Science.gov

Sample records for alaska greenland turbot

  1. 75 FR 38940 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Aleutian Islands...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    ... BSAI (75 FR 11778, March 12, 2010). In accordance with Sec. 679.20(d)(1)(i), the Administrator, Alaska... Economic Zone Off Alaska; Greenland Turbot in the Aleutian Islands Subarea of the Bering Sea and Aleutian... for Greenland turbot in the Aleutian Islands subarea of the Bering Sea and Aleutian Islands...

  2. 78 FR 54591 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Bering Sea and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-05

    ... under Sec. 679.20(d)(1)(iii) on May 1, 2013 (78 FR 24361, April 25, 2013). NMFS has determined that as... Economic Zone Off Alaska; Greenland Turbot in the Bering Sea and Aleutian Islands Management Area AGENCY... Greenland turbot in the Bering Sea subarea of the Bering Sea and Aleutian Islands Management Area...

  3. 76 FR 71269 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Bering Sea Subarea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-17

    ... groundfish in the BSAI (76 FR 11139, March 1, 2011). The harvest specification for the 2011 Greenland turbot... 2011 and 2012 harvest specifications for groundfish of the BSAI (76 FR 11139, March 1, 2011). In... Economic Zone Off Alaska; Greenland Turbot in the Bering Sea Subarea of the Bering Sea and Aleutian...

  4. 78 FR 24361 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Bering Sea Subarea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ... and 2014 harvest specifications for groundfish in the BSAI (78 FR 13813, March 1, 2013). In accordance... Economic Zone Off Alaska; Greenland Turbot in the Bering Sea Subarea of the Bering Sea and Aleutian Islands... for Greenland turbot in the Bering Sea subarea of the Bering Sea and Aleutian Islands management...

  5. 78 FR 24362 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Aleutian Islands...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ... the final 2013 and 2014 harvest specifications for groundfish in the BSAI (78 FR 13813, March 1, 2013... Economic Zone Off Alaska; Greenland Turbot in the Aleutian Islands Subarea of the Bering Sea and Aleutian... for Greenland turbot in the Aleutian Islands subarea of the Bering Sea and Aleutian Islands...

  6. 75 FR 38430 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Aleutian Islands...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... and 2011 harvest specifications for groundfish of the BSAI (75 FR 11788, March 12, 2010). In... specifications for groundfish in the BSAI (75 FR 11788, March 12, 2010). The harvest specification for the 2010... Economic Zone Off Alaska; Greenland Turbot in the Aleutian Islands Subarea of the Bering Sea and...

  7. 21 CFR 102.57 - Greenland turbot (Reinhardtius hippoglossoides).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Greenland turbot (Reinhardtius hippoglossoides... for Specific Nonstandardized Foods § 102.57 Greenland turbot (Reinhardtius hippoglossoides). “Greenland turbot” is the common or usual name of the food fish Reinhardtius hippoglossoides, a species...

  8. 21 CFR 102.57 - Greenland turbot (Reinhardtius hippoglossoides).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Greenland turbot (Reinhardtius hippoglossoides... for Specific Nonstandardized Foods § 102.57 Greenland turbot (Reinhardtius hippoglossoides). “Greenland turbot” is the common or usual name of the food fish Reinhardtius hippoglossoides, a species...

  9. 21 CFR 102.57 - Greenland turbot (Reinhardtius hippoglossoides).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Greenland turbot (Reinhardtius hippoglossoides... for Specific Nonstandardized Foods § 102.57 Greenland turbot (Reinhardtius hippoglossoides). “Greenland turbot” is the common or usual name of the food fish Reinhardtius hippoglossoides, a species...

  10. 21 CFR 102.57 - Greenland turbot (Reinhardtius hippoglossoides).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Greenland turbot (Reinhardtius hippoglossoides... for Specific Nonstandardized Foods § 102.57 Greenland turbot (Reinhardtius hippoglossoides). “Greenland turbot” is the common or usual name of the food fish Reinhardtius hippoglossoides, a species...

  11. Killer whale depredation and associated costs to Alaskan sablefish, Pacific halibut and Greenland turbot longliners.

    PubMed

    Peterson, Megan J; Mueter, Franz; Criddle, Keith; Haynie, Alan C

    2014-01-01

    Killer whale (Orcinus orca) depredation (whales stealing or damaging fish caught on fishing gear) adversely impacts demersal longline fisheries for sablefish (Anoplopoma fimbria), Pacific halibut (Hippoglossus stenolepis) and Greenland turbot (Reinhardtius hippoglossoides) in the Bering Sea, Aleutian Islands and Western Gulf of Alaska. These interactions increase direct costs and opportunity costs associated with catching fish and reduce the profitability of longline fishing in western Alaska. This study synthesizes National Marine Fisheries Service observer data, National Marine Fisheries Service sablefish longline survey and fishermen-collected depredation data to: 1) estimate the frequency of killer whale depredation on longline fisheries in Alaska; 2) estimate depredation-related catch per unit effort reductions; and 3) assess direct costs and opportunity costs incurred by longliners in western Alaska as a result of killer whale interactions. The percentage of commercial fishery sets affected by killer whales was highest in the Bering Sea fisheries for: sablefish (21.4%), Greenland turbot (9.9%), and Pacific halibut (6.9%). Average catch per unit effort reductions on depredated sets ranged from 35.1-69.3% for the observed longline fleet in all three management areas from 1998-2012 (p<0.001). To compensate for depredation, fishermen set additional gear to catch the same amount of fish, and this increased fuel costs by an additional 82% per depredated set (average $433 additional fuel per depredated set). In a separate analysis with six longline vessels in 2011 and 2012, killer whale depredation avoidance measures resulted in an average additional cost of $494 per depredated vessel-day for fuel and crew food. Opportunity costs of time lost by fishermen averaged $522 per additional vessel-day on the grounds. This assessment of killer whale depredation costs represents the most extensive economic evaluation of this issue in Alaska to date and will help longline

  12. Killer whale depredation and associated costs to Alaskan sablefish, Pacific halibut and Greenland turbot longliners.

    PubMed

    Peterson, Megan J; Mueter, Franz; Criddle, Keith; Haynie, Alan C

    2014-01-01

    Killer whale (Orcinus orca) depredation (whales stealing or damaging fish caught on fishing gear) adversely impacts demersal longline fisheries for sablefish (Anoplopoma fimbria), Pacific halibut (Hippoglossus stenolepis) and Greenland turbot (Reinhardtius hippoglossoides) in the Bering Sea, Aleutian Islands and Western Gulf of Alaska. These interactions increase direct costs and opportunity costs associated with catching fish and reduce the profitability of longline fishing in western Alaska. This study synthesizes National Marine Fisheries Service observer data, National Marine Fisheries Service sablefish longline survey and fishermen-collected depredation data to: 1) estimate the frequency of killer whale depredation on longline fisheries in Alaska; 2) estimate depredation-related catch per unit effort reductions; and 3) assess direct costs and opportunity costs incurred by longliners in western Alaska as a result of killer whale interactions. The percentage of commercial fishery sets affected by killer whales was highest in the Bering Sea fisheries for: sablefish (21.4%), Greenland turbot (9.9%), and Pacific halibut (6.9%). Average catch per unit effort reductions on depredated sets ranged from 35.1-69.3% for the observed longline fleet in all three management areas from 1998-2012 (p<0.001). To compensate for depredation, fishermen set additional gear to catch the same amount of fish, and this increased fuel costs by an additional 82% per depredated set (average $433 additional fuel per depredated set). In a separate analysis with six longline vessels in 2011 and 2012, killer whale depredation avoidance measures resulted in an average additional cost of $494 per depredated vessel-day for fuel and crew food. Opportunity costs of time lost by fishermen averaged $522 per additional vessel-day on the grounds. This assessment of killer whale depredation costs represents the most extensive economic evaluation of this issue in Alaska to date and will help longline

  13. Native Language Dictionaries and Grammars of Alaska, Northern Canada, and Greenland.

    ERIC Educational Resources Information Center

    Goniwiecha, Mark C.; Hales, David A.

    1988-01-01

    Describes recent political and social activities aimed at preserving the culture of Native Americans in Alaska, Northern Canada, and Greenland. An annotated bibliography of sources for the Eskimo Aleut, Tsimshian, Haida, Athabascan (Athapascan), Eyak and Tlingit languages is provided. (CLB)

  14. Correlation of the Cretaceous formations of Greenland and Alaska

    USGS Publications Warehouse

    Imlay, Ralph Willard; Reeside, John B.

    1953-01-01

    This is Number 10d of a series of correlation charts prepared for the Committee on Stratigraphy of the National Research Council. It has been sponsored by the U.S. Geological Survey and has required about seven months' time of both authors gathering and compiling data and evaluating fossil evidence. As the two regions dealt with in the chart are widely separated, the lists of references are also given separately. The annotations dealing with Greenland are based entirely on published information. The annotations dealing with Alaska are based on a re-examination of nearly all the Cretaceous fossils from Alaska are based on a re-examination of nearly all the Cretaceous fossils from Alaska in the collections of the Geological Survey. This has resulted in many concepts not hitherto published and in some concepts that are completely at variance with those that have been published. Naturally for large areas undergoing active exploration, such as Alaska, a correlation chart is out of date in many particulars as soon as published. Nevertheless it is valuable to the field man whose activities are confined to small areas but who must interpret much of his data in terms of surrounding areas that he has not seen. It is valuable to the student and to the general geologist because it organizes scattered information in a manner that can be applied in their field problems, makes quite unnecessary the memorization of stratigraphic correlations are based on observation and reasoning and not on a vast memory. It is probably of greatest value to the specialist who makes the chart because he discovers what areas and problems are most in need of research and can thereby direct his efforts and those of his associates in a manner that will yield the greatest results.

  15. NOAA Atmospheric Baseline Observatories in the Arctic: Alaska & Greenland

    NASA Astrophysics Data System (ADS)

    Vasel, B. A.; Butler, J. H.; Schnell, R. C.; Crain, R.; Haggerty, P.; Greenland, S.

    2013-12-01

    The National Oceanic and Atmospheric Administration (NOAA) operates two year-round, long-term climate research facilities, known as Atmospheric Baseline Observatories (ABOs), in the Arctic Region. The Arctic ABOs are part of a core network to support the NOAA Global Monitoring Division's mission to acquire, evaluate, and make available accurate, long-term records of atmospheric gases, aerosol particles, and solar radiation in a manner that allows the causes of change to be understood. The observatory at Barrow, Alaska (BRW) was established in 1973 and is now host to over 200 daily measurements. Located a few kilometers to the east of the village of Barrow at 71.3° N it is also the northernmost point in the United States. Measurement records from Barrow are critical to our understanding of the Polar Regions including exchange among tundra, atmosphere, and ocean. Multiple data sets are available for carbon cycle gases, halogenated gases, solar radiation, aerosol properties, ozone, meteorology, and numerous others. The surface, in situ carbon dioxide record alone consists of over 339,000 measurements since the system was installed in July 1973. The observatory at Summit, Greenland (SUM) has been a partnership with the National Science Foundation (NSF) Division of Polar Programs since 2004, similar to that for South Pole. Observatory data records began in 1997 from this facility located at the top of the Greenland ice sheet at 72.58° N. Summit is unique as the only high-altitude (3200m), mid-troposphere, inland, Arctic observatory, largely free from outside local influences such as thawing tundra or warming surface waters. The measurement records from Summit help us understand long-range transport across the Arctic region, as well as interactions between air and snow. Near-real-time data are available for carbon cycle gases, halogenated gases, solar radiation, aerosol properties, meteorology, ozone, and numerous others. This poster will highlight the two facilities

  16. Cross-Cultural Education and the Economic Situation: The Greenland and Alaska Cases.

    ERIC Educational Resources Information Center

    Rogers, George W.

    The paper examines the economic situations in Greenland and Alaska. Similar in many ways, the 2 countries represent opposite policy poles from a cultural standpoint. The basic economic problem is one of severe regional imbalance when compared with the rest of the nation. For both, government policy has tried to raise income and consumption to a…

  17. Ice mass loss in Greenland, the Gulf of Alaska, and the Canadian Archipelago: Seasonal cycles and decadal trends

    NASA Astrophysics Data System (ADS)

    Harig, Christopher; Simons, Frederik J.

    2016-04-01

    Over the past several decades mountain glaciers and ice caps have been significant contributors to sea level rise. Here we estimate the ice mass changes in the Canadian Archipelago, the Gulf of Alaska, and Greenland since 2003 by analyzing time-varying gravimetry data from the Gravity Recovery and Climate Experiment. Prior to 2013, interannual ice mass variability in the Gulf of Alaska and in regions around Greenland remains within the average estimated over the whole data span. Beginning in summer 2013, ice mass in regions around Greenland departs positively from its long-term trend. Over Greenland this anomaly reached almost 500 Gt through the end of 2014. Overall, long-term ice mass loss from Greenland and the Canadian Archipelago continues to accelerate, while losses around the Gulf of Alaska region continue but remain steady with no significant acceleration.

  18. Methane seeps along boundaries of receding glaciers in Alaska and Greenland

    NASA Astrophysics Data System (ADS)

    Walter Anthony, K. M.; Anthony, P. M.; Grosse, G.; Chanton, J.

    2012-12-01

    Glaciers, ice sheets, and permafrost form a 'cryosphere cap' that traps methane formed in the subsurface, restricting its flow to the Earth's surface and atmosphere. Despite model predictions that glacier melt and degradation of permafrost open conduits for methane's escape, there has been a paucity of field evidence for 'subcap' methane seepage to the atmosphere as a direct result of cryosphere disintegration in the terrestrial Arctic. Here, we document for the first time the release of sub-cryosphere methane to lakes, rivers, shallow marine fjords and the atmosphere from abundant gas seeps concentrated along boundaries of receding glaciers and permafrost thaw in Alaska and Greenland. Through aerial and ground surveys of 6,700 lakes and fjords in Alaska we mapped >150,000 gas seeps identified as bubbling-induced open holes in seasonal ice. Using gas flow rates, stable isotopes, and radiocarbon dating, we distinguished recent ecological methane from subcap, geologic methane. Subcap seeps had anomalously high bubbling rates, 14C-depletion, and stable isotope values matching microbial sources associated with sedimentary deposits and coal beds as well as thermogenic methane accumulations in Alaska. Since differential ice loading can overpressurize fluid reservoirs and cause sediment fracturing beneath ice sheets, and since the loss of glacial ice reduces normal stress on ground, opens joints, and activates faults and fissures, thereby increasing permeability of the crust to fluid flow, we hypothesized that in the previously glaciated region of Southcentral Alaska, where glacial wastage continues presently, subcap seeps should be disproportionately associated with neotectonic faults. Geospatial analysis confirmed that subcap seep sites were associated with faults within a 7 km belt from the modern glacial extent. The majority of seeps were located in areas affected by seismicity from isostatic rebound associated with deglaciation following the Little Ice Age (LIA; ca

  19. 78 FR 76245 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Bering Sea Subarea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE... Administration (NOAA), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS is prohibiting directed fishing... and 2014 harvest specifications for groundfish in the BSAI (78 FR 13813, March 1, 2013). In...

  20. Flow Characteristics of Tidewater Glaciers in Greenland and Alaska using Ground-Based LiDAR

    NASA Astrophysics Data System (ADS)

    Finnegan, D. C.; Stearns, L. A.; Hamilton, G. S.; O'Neel, S.

    2010-12-01

    LiDAR scanning systems have been employed to characterize and quantify multi-temporal glacier and ice sheet changes for nearly three decades. Until recently, LiDAR scanning systems were limited to airborne and space-based platforms which come at a significant cost to deploy and are limited in spatial and temporal sampling capabilities necessary to compare with in-situ field measurements. Portable ground-based LiDAR scanning systems are now being used as a glaciological tool. We discuss research efforts to employ ground-based near-infrared LiDAR systems at two differing tidewater glacier systems in the spring of 2009; Helheim Glacier in southeast Greenland and Columbia Glacier in southeast Alaska. Preliminary results allow us to characterize short term displacement rates and detailed observations of calving processes. These results highlight the operational limitations and capabilities of commercially available LiDAR systems, and allow us to identify optimal operating characteristics for monitoring small to large-scale tidewater glaciers in near real-time. Furthermore, by identifying the operational limitations of these sensors it allows for optimal design characteristics of new sensors necessary to meet ground-based calibration and validation requirements of ongoing scientific missions.

  1. Regional sea level change in response to ice mass loss in Greenland, the West Antarctic and Alaska

    NASA Astrophysics Data System (ADS)

    Brunnabend, S.-E.; Schröter, J.; Rietbroek, R.; Kusche, J.

    2015-11-01

    Besides the warming of the ocean, sea level is mainly rising due to land ice mass loss of the major ice sheets in Greenland, the West Antarctic, and the Alaskan Glaciers. However, it is not clear yet how these land ice mass losses influence regional sea level. Here, we use the global Finite Element Sea-ice Ocean Model (FESOM) to simulate sea surface height (SSH) changes caused by these ice mass losses and combine it with the passive ocean response to varying surface loading using the sea level equation. We prescribe rates of fresh water inflow, not only around Greenland, but also around the West Antarctic Ice Sheet and the mountain glaciers in Alaska with approximately present-day amplitudes of 200, 100, and 50 Gt/yr, respectively. Perturbations in sea level and in freshwater distribution with respect to a reference simulation are computed for each source separately and in their combination. The ocean mass change shows an almost globally uniform behavior. In the North Atlantic and Arctic Ocean, mass is redistributed toward coastal regions. Steric sea level change varies locally in the order of several centimeters on advective timescales of decades. Steric effects to local sea level differ significantly in different coastal locations, e.g., at North American coastal regions the steric effects may have the same order of magnitude as the mass driven effect, whereas at the European coast, steric effects remain small during the simulation period.

  2. Tradition and transition: parasitic zoonoses of people and animals in Alaska, northern Canada, and Greenland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zoonotic parasites have been recognized as important causes of endemic and emerging human disease in northern North America and Greenland, with increased prevalence of some parasites in Indigenous and northern residents as compared to the general North American population. This is in part due to tr...

  3. Antarctica, Greenland and Gulf of Alaska Land-ice Evolution from an Iterated GRACE Global Mascon Solution

    NASA Technical Reports Server (NTRS)

    Luthcke, Scott B.; Sabaka, T. J.; Loomis, B. D.; Arendt, A. A.; McCarthy, J. J.; Camp, J.

    2013-01-01

    We have determined the ice mass evolution of the Antarctica and Greenland ice sheets (AIS and GIS) and Gulf of Alaska (GOA) glaciers from a new GRACE global solution of equal-area surface mass concentration parcels (mascons) in equivalent height of water. The mascons were estimated directly from the reduction of the inter-satellite K-band range-rate (KBRR) observations, taking into account the full noise covariance, and formally iterating the solution. The new solution increases signal recovery while reducing the GRACE KBRR observation residuals. The mascons were estimated with 10 day and 1 arc degree equal-area sampling, applying anisotropic constraints. An ensemble empirical mode decomposition adaptive filter was applied to the mascon time series to compute annual mass balances. The details and causes of the spatial and temporal variability of the land-ice regions studied are discussed. The estimated mass trend over the total GIS, AIS and GOA glaciers for the time period 1 December 2003 to 1 December 2010 is -380 plus or minus 31 Gt a(exp -1), equivalent to -1.05 plus or minus 0.09 mma(exp -1) sea-level rise. Over the same time period we estimate the mass acceleration to be -41 plus or minus 27 Gt a(exp -2), equivalent to a 0.11 plus or minus 0.08 mm a(exp -2) rate of change in sea level. The trends and accelerations are dependent on significant seasonal and annual balance anomalies.

  4. Antarctica, Greenland and Gulf of Alaska Land-Ice Evolution from an Iterated GRACE Global Mascon Solution

    NASA Technical Reports Server (NTRS)

    Luthcke, Scott B.; Sabaka, T. J.; Loomis, B. D.; Arendt, A. A.; McCarthy, J. J.; Camp, J.

    2013-01-01

    We have determined the ice mass evolution of the Antarctica and Greenland ice sheets (AIS and GIS) and Gulf of Alaska (GOA) glaciers from a new GRACE global solution of equal-area surface mass concentration parcels (mascons) in equivalent height of water. The mascons were estimated directly from the reduction of the inter-satellite K-band range-rate (KBRR) observations, taking into account the full noise covariance, and formally iterating the solution. The new solution increases signal recovery while reducing the GRACE KBRR observation residuals. The mascons were estimated with 10 day and 1 arc degree equal-area sampling, applying anisotropic constraints. An ensemble empirical mode decomposition adaptive filter was applied to the mascon time series to compute annual mass balances. The details and causes of the spatial and temporal variability of the land-ice regions studied are discussed. The estimated mass trend over the total GIS, AIS and GOA glaciers for the time period 1 December 2003 to 1 December 2010 is -380 plus or minus 31 Gt a(exp -1), equivalent to -1.05 plus or minus 0.09 mma(exp -1) sea-level rise. Over the same time period we estimate the mass acceleration to be -41 plus or minus 27 Gt a(exp -2), equivalent to a 0.11 plus or minus 0.08 mm a(exp -2) rate of change in sea level. The trends and accelerations are dependent on significant seasonal and annual balance anomalies.

  5. Overseas trip report, CV 990 underflight mission. [Norwegian Sea, Greenland ice sheet, and Alaska

    NASA Technical Reports Server (NTRS)

    Gloersen, P.; Crawford, J.; Hardis, L.

    1980-01-01

    The scanning microwave radiometer-7 simulator, the ocean temperature scanner, and an imaging scatterometer/altimeter operating at 14 GHz were carried onboard the NASA CV-990 over open oceans, sea ice, and continental ice sheets to gather surface truth information. Data flights were conducted over the Norwegian Sea to map the ocean polar front south and west of Bear Island and to transect several Nimbus-7 footprints in a rectangular pattern parallel to the northern shoreline of Norway. Additional flights were conducted to obtain correlative data on the cryosphere parameters and characteristics of the Greenland ice sheet, and study the frozen lakes near Barrow. The weather conditions and flight path way points for each of the nineteen flights are presented in tables and maps.

  6. Results and Error Estimates from GRACE Forward Modeling over Greenland, Canada, and Alaska

    NASA Astrophysics Data System (ADS)

    Bonin, J. A.; Chambers, D. P.

    2012-12-01

    Forward modeling using a weighted least squares technique allows GRACE information to be projected onto a pre-determined collection of local basins. This decreases the impact of spatial leakage, allowing estimates of mass change to be better localized. The technique is especially valuable where models of current-day mass change are poor, such as over Greenland and Antarctica. However, the accuracy of the forward model technique has not been determined, nor is it known how the distribution of the local basins affects the results. We use a "truth" model composed of hydrology and ice-melt slopes as an example case, to estimate the uncertainties of this forward modeling method and expose those design parameters which may result in an incorrect high-resolution mass distribution. We then apply these optimal parameters in a forward model estimate created from RL05 GRACE data. We compare the resulting mass slopes with the expected systematic errors from the simulation, as well as GIA and basic trend-fitting uncertainties. We also consider whether specific regions (such as Ellesmere Island and Baffin Island) can be estimated reliably using our optimal basin layout.

  7. Flame retardants and legacy contaminants in polar bears from Alaska, Canada, East Greenland and Svalbard, 2005-2008.

    PubMed

    McKinney, Melissa A; Letcher, Robert J; Aars, Jon; Born, Erik W; Branigan, Marsha; Dietz, Rune; Evans, Thomas J; Gabrielsen, Geir W; Peacock, Elizabeth; Sonne, Christian

    2011-02-01

    Flame retardants and legacy contaminants were analyzed in adipose tissue from 11 circumpolar polar bear (Ursus maritimus) subpopulations in 2005-2008 spanning Alaska east to Svalbard. Although 37 polybrominated diphenyl ethers (PBDEs), total-(α)-hexabromocyclododecane (HBCD), 2 polybrominated biphenyls (PBBs), pentabromotoluene, pentabromoethylbenzene, hexabromobenzene, 1,2-bis(2,4,6-tribromophenoxy(ethane) and decabromodiphenyl ethane were screened, only 4 PBDEs, total-(α-)HBCD and BB153 were consistently found. Geometric mean ΣPBDE (4.6-78.4 ng/g lipid weight (lw)) and BB153 (2.5-81.1 ng/g lw) levels were highest in East Greenland (43.2 and 39.2 ng/g lipid weight (lw), respectively), Svalbard (44.4 and 20.9 ng/g lw) and western (38.6 and 30.1 ng/g lw) and southern Hudson Bay (78.4 and 81.1 ng/g lw). Total-(α)-HBCD levels (<0.3-41.1 ng/g lw) were lower than ΣPBDE levels in all subpopulations except in Svalbard, consistent with greater European HBCD use versus North American pentaBDE product use. ΣPCB levels were high relative to flame retardants as well as other legacy contaminants and increased from west to east (1797-10,537 ng/g lw). ΣCHL levels were highest among legacy organochlorine pesticides and relatively spatially uniform (765-3477 ng/g lw). ΣDDT levels were relatively low and spatially variable (31.5-206 ng/g lw). However, elevated proportions of p,p'-DDT to ΣDDT in Alaska and Beaufort Sea relative to other subpopulations suggested fresh inputs from vector control use in Asia and/or Africa. Comparing earlier circumpolar polar bear studies, ΣPBDE, total-(α)-HBCD, p,p'-DDE and ΣCHL levels consistently declined, whereas levels of other legacy contaminants did not. International regulations have clearly been effective in reducing levels of several legacy contaminants in polar bears relative to historical levels. However, slow or stalling declines of certain historic pollutants like PCBs and a complex mixture of "new" chemicals continue to be of

  8. Tradition and transition: parasitic zoonoses of people and animals in Alaska, northern Canada, and Greenland.

    PubMed

    Jenkins, Emily J; Castrodale, Louisa J; de Rosemond, Simone J C; Dixon, Brent R; Elmore, Stacey A; Gesy, Karen M; Hoberg, Eric P; Polley, Lydden; Schurer, Janna M; Simard, Manon; Thompson, R C Andrew

    2013-01-01

    Zoonotic parasites are important causes of endemic and emerging human disease in northern North America and Greenland (the North), where prevalence of some parasites is higher than in the general North American population. The North today is in transition, facing increased resource extraction, globalisation of trade and travel, and rapid and accelerating environmental change. This comprehensive review addresses the diversity, distribution, ecology, epidemiology, and significance of nine zoonotic parasites in animal and human populations in the North. Based on a qualitative risk assessment with criteria heavily weighted for human health, these zoonotic parasites are ranked, in the order of decreasing importance, as follows: Echinococcus multilocularis, Toxoplasma gondii, Trichinella and Giardia, Echinococcus granulosus/canadensis and Cryptosporidium, Toxocara, anisakid nematodes, and diphyllobothriid cestodes. Recent and future trends in the importance of these parasites for human health in the North are explored. For example, the incidence of human exposure to endemic helminth zoonoses (e.g. Diphyllobothrium, Trichinella, and Echinococcus) appears to be declining, while water-borne protozoans such as Giardia, Cryptosporidium, and Toxoplasma may be emerging causes of human disease in a warming North. Parasites that undergo temperature-dependent development in the environment (such as Toxoplasma, ascarid and anisakid nematodes, and diphyllobothriid cestodes) will likely undergo accelerated development in endemic areas and temperate-adapted strains/species will move north, resulting in faunal shifts. Food-borne pathogens (e.g. Trichinella, Toxoplasma, anisakid nematodes, and diphyllobothriid cestodes) may be increasingly important as animal products are exported from the North and tourists, workers, and domestic animals enter the North. Finally, key needs are identified to better assess and mitigate risks associated with zoonotic parasites, including enhanced

  9. Tradition and transition: parasitic zoonoses of people and animals in Alaska, northern Canada, and Greenland.

    PubMed

    Jenkins, Emily J; Castrodale, Louisa J; de Rosemond, Simone J C; Dixon, Brent R; Elmore, Stacey A; Gesy, Karen M; Hoberg, Eric P; Polley, Lydden; Schurer, Janna M; Simard, Manon; Thompson, R C Andrew

    2013-01-01

    Zoonotic parasites are important causes of endemic and emerging human disease in northern North America and Greenland (the North), where prevalence of some parasites is higher than in the general North American population. The North today is in transition, facing increased resource extraction, globalisation of trade and travel, and rapid and accelerating environmental change. This comprehensive review addresses the diversity, distribution, ecology, epidemiology, and significance of nine zoonotic parasites in animal and human populations in the North. Based on a qualitative risk assessment with criteria heavily weighted for human health, these zoonotic parasites are ranked, in the order of decreasing importance, as follows: Echinococcus multilocularis, Toxoplasma gondii, Trichinella and Giardia, Echinococcus granulosus/canadensis and Cryptosporidium, Toxocara, anisakid nematodes, and diphyllobothriid cestodes. Recent and future trends in the importance of these parasites for human health in the North are explored. For example, the incidence of human exposure to endemic helminth zoonoses (e.g. Diphyllobothrium, Trichinella, and Echinococcus) appears to be declining, while water-borne protozoans such as Giardia, Cryptosporidium, and Toxoplasma may be emerging causes of human disease in a warming North. Parasites that undergo temperature-dependent development in the environment (such as Toxoplasma, ascarid and anisakid nematodes, and diphyllobothriid cestodes) will likely undergo accelerated development in endemic areas and temperate-adapted strains/species will move north, resulting in faunal shifts. Food-borne pathogens (e.g. Trichinella, Toxoplasma, anisakid nematodes, and diphyllobothriid cestodes) may be increasingly important as animal products are exported from the North and tourists, workers, and domestic animals enter the North. Finally, key needs are identified to better assess and mitigate risks associated with zoonotic parasites, including enhanced

  10. Spatial and temporal trends of selected trace elements in liver tissue from polar bears (Ursus maritimus) from Alaska, Canada and Greenland

    USGS Publications Warehouse

    Routti, H.; Letcher, R.J.; Born, E.W.; Branigan, M.; Dietz, R.; Evans, T.J.; Fisk, A.T.; Peacock, E.; Sonne, C.

    2011-01-01

    Spatial trends and comparative changes in time of selected trace elements were studied in liver tissue from polar bears from ten different subpopulation locations in Alaska, Canadian Arctic and East Greenland. For nine of the trace elements (As, Cd, Cu, Hg, Mn, Pb, Rb, Se and Zn) spatial trends were investigated in 136 specimens sampled during 2005-2008 from bears from these ten subpopulations. Concentrations of Hg, Se and As were highest in the (northern and southern) Beaufort Sea area and lowest in (western and southern) Hudson Bay area and Chukchi/Bering Sea. In contrast, concentrations of Cd showed an increasing trend from east to west. Minor or no spatial trends were observed for Cu, Mn, Rb and Zn. Spatial trends were in agreement with previous studies, possibly explained by natural phenomena. To assess temporal changes of Cd, Hg, Se and Zn concentrations during the last decades, we compared our results to previously published data. These time comparisons suggested recent Hg increase in East Greenland polar bears. This may be related to Hg emissions and/or climate-induced changes in Hg cycles or changes in the polar bear food web related to global warming. Also, Hg:Se molar ratio has increased in East Greenland polar bears, which suggests there may be an increased risk for Hg 2+-mediated toxicity. Since the underlying reasons for spatial trends or changes in time of trace elements in the Arctic are still largely unknown, future studies should focus on the role of changing climate and trace metal emissions on geographical and temporal trends of trace elements. ?? 2011 The Royal Society of Chemistry.

  11. Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Though it's not quite spring, waters in the Gulf of Alaska (right) appear to be blooming with plant life in this true-color MODIS image from March 4, 2002. East of the Alaska Peninsula (bottom center), blue-green swirls surround Kodiak Island. These colors are the result of light reflecting off chlorophyll and other pigments in tiny marine plants called phytoplankton. The bloom extends southward and clear dividing line can be seen west to east, where the bloom disappears over the deeper waters of the Aleutian Trench. North in Cook Inlet, large amounts of red clay sediment are turning the water brown. To the east, more colorful swirls stretch out from Prince William Sound, and may be a mixture of clay sediment from the Copper River and phytoplankton. Arcing across the top left of the image, the snow-covered Brooks Range towers over Alaska's North Slope. Frozen rivers trace white ribbons across the winter landscape. The mighty Yukon River traverses the entire state, beginning at the right edge of the image (a little way down from the top) running all the way over to the Bering Sea, still locked in ice. In the high-resolution image, the circular, snow-filled calderas of two volcanoes are apparent along the Alaska Peninsula. In Bristol Bay (to the west of the Peninsula) and in a couple of the semi-clear areas in the Bering Sea, it appears that there may be an ice algae bloom along the sharp ice edge (see high resolution image for better details). Ground-based observations from the area have revealed that an under-ice bloom often starts as early as February in this region and then seeds the more typical spring bloom later in the season.

  12. 21 CFR 102.57 - Greenland turbot (Reinhardtius hippoglossoides).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...). 102.57 Section 102.57 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION COMMON OR USUAL NAME FOR NONSTANDARDIZED FOODS Requirements... Pleuronectidae right-eye flounders. The term “halibut” may be associated only with Atlantic halibut...

  13. Colour preferences of juvenile turbot (Scophthalmus maximus).

    PubMed

    Li, Xian; Chi, Liang; Tian, Huiqin; Meng, Lingjie; Zheng, Jimeng; Gao, Xiaolong; Liu, Ying

    2016-03-15

    The background colour of aquaculture tanks is normally chosen based on practical experience and/or observations of fish behaviour and the growth rates achieved. However, some farmed species, including turbot, are sentient and can show a preference for a particular environment. In the current study, a self-referent colour preference device was developed and the self-referent colour preference of farmed fish investigated. In experiment 1, the background colour preference of juvenile turbot cultured under a grey background for >3months post-incubation was evaluated. Based on these results, in experiment 2, juvenile turbot were adapted to blue, pink, white, or black backgrounds for 50days and their preferences established. Meanwhile, the growth rates, feed intake, and metabolic rates (including oxygen consumption rate, and ammonia excretion rate) of the turbot were evaluated. The results showed that turbot farmed under a grey background, or after long-term white, blue, pink and black colour adaptation, always displayed a preference for a white background and a dislike for black, red, or brown backgrounds, although their body colour was greyish. Long-term adaptation influenced the frequency of juveniles selecting white, black, pink or blue backgrounds. They showed the highest growth rate, feed intake, and metabolic rates under blue and white backgrounds, and the lowest under a black background in accordance with their preferences shown in experiment 1. Although it is unclear how turbot determine their self-referent colour preferences over such a short period of time, these results indicate that dark colours are unsuitable for the aquaculture of turbot culture in terms of the welfare of the fish. PMID:26792527

  14. Gravity anomaly at a Pleistocene lake bed in NW Alaska interpreted by analogy with Greenland's Lake Taserssauq and its floating ice tongue

    USGS Publications Warehouse

    Barnes, D.F.

    1987-01-01

    A possible example of a very deep glacial excavation is provided by a distinctive gravity low located at the front of a valley glacier that once flowed into glacial Lake Aniuk (formerly Lake Noatak) in the western Brooks Range. Geologic and geophysical data suggest that sediments or ice filling a glacially excavated valley are the most probable cause of the 30-50 mGal anomaly. Reasonable choices of geometric models and density contrasts indicate that the former excavation is now filled with a buried-ice thickness of 700 m or sediment thicknesses greater than 1 km. No direct evidence of efficient excavation was observed in Greenland, but efficient glacial erosion behind a floating polar ice tongue could explain the excavation that caused the Alaskan gravity anomaly. -from Author

  15. Nuuk, Greenland

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Nuuk (or Gadthab) is the capital and largest city of Greenland. It is located at the mouth of the Nuup Kangerlua inlet on the west coast of Greenland. It has a population of about 15,000. The site has a long history of different inhabitation: first by the Inuit people around 2000 B.C., later by Viking explorers in the 10th century. Inuit and Vikings lived together for about 500 years until about 1500, when human habitation suddenly stopped, most likely due to change in climate and vegetation.

    The image was acquired August 2, 2004, covers an area of 22.7 x 26 km, and is located at 64.2 degrees north latitude, 51.8 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  16. Biogeochemical Indicators in High- and Low-Arctic Marine and Terrestrial Avian Community Changes: Comparative Isotopic (13C, 15N, and 34S) Studies in Alaska and Greenland

    NASA Astrophysics Data System (ADS)

    Causey, D.; Bargmann, N. A.; Burnham, K. K.; Burnham, J. L.; Padula, V. M.; Johnson, J. A.; Welker, J. M.

    2011-12-01

    Understanding the complex dynamics of environmental change in northern latitudes is of paramount importance today, given documented rapid shifts in sea ice, plant phenology, temperatures, deglaciation, and habitat fidelity. This knowledge is particularly critical for Arctic avian communities, which are integral components by which biological teleconnections are maintained between the mid and northern latitudes. Furthermore, Arctic birds are fundamental to Native subsistence lifestyles and a focus for conservation activities. Avian communities of marine and terrestrial Arctic environments represent a broad spectrum of trophic levels, from herbivores (eg., geese Chen spp.), planktivores (eg., auklets Aethia spp.), and insectivores (eg., passerines: Wheatears Oenanthe spp., Longspurs Calcarius spp.), to predators of marine invertebrates (eg., eiders Somateria spp.), nearshore and offshore fish (eg., cormorants Phalacrocorax spp, puffins Fratercula spp.), even other bird species (eg., gulls Larus spp., falcons Peregrinus spp.). This diversity of trophic interconnections is an integral factor in the dynamics of Arctic ecosystem ecology, and they are key indicators for the strength and trajectories of change. We are especially interested in their feeding ecology, using stable isotope-diet relations to examine historical diets and to predict future feeding ecology by this range of species. Since 2009, we have been studying the foodweb ecology using stable isotopes (δ13C, δ15N, δ34S) of contemporaneous coastal and marine bird communities in High Arctic (Northwest Greenland) and Low Arctic (western Aleutian Islands, AK). We are quantifying the isotopic values of blood, organ tissues, and feathers, and have carried out comparisons between native and lipid-extracted samples. Although geographically distant, these communities comprise similar taxonomic and ecological congeners, including several species common to both (eg., Common Eider, Black-legged Kittiwake, Northern

  17. Characterization of gonadal transcriptomes from the turbot (Scophthalmus maximus).

    PubMed

    Hu, Yulong; Huang, Meng; Wang, Weiji; Guan, Jiantao; Kong, Jie

    2016-01-01

    The mechanisms underlying sexual reproduction and sex ratio determination remains unclear in turbot, a flatfish of great commercial value. And there is limited information in the turbot database regarding genes related to the reproductive system. Here, we conducted high-throughput transcriptome profiling of turbot gonad tissues to better understand their reproductive functions and to supply essential gene sequence information for marker-assisted selection programs in the turbot industry. In this study, two gonad libraries representing sex differences in Scophthalmus maximus yielded 453 818 high-quality reads that were assembled into 24 611 contigs and 33 713 singletons by using 454 pyrosequencing, 13 936 contigs and singletons (CS) of which were annotated using BLASTx. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analyses revealed that various biological functions and processes were associated with many of the annotated CS. Expression analyses showed that 510 genes were differentially expressed in males versus females; 80% of these genes were annotated. In addition, 6484 and 6036 single nucleotide polymorphisms (SNPs) were identified in male and female libraries, respectively. This transcriptome resource will serve as the foundation for cDNA or SNP microarray construction, gene expression characterization, and sex-specific linkage mapping in turbot. PMID:26745327

  18. Post-release survival and feeding in reared turbot

    NASA Astrophysics Data System (ADS)

    Sparrevohn, Claus R.; Støttrup, Josianne G.

    2007-02-01

    As part of the Danish restocking program, an experiment was carried out with four groups of turbot Psetta maxima released on two different occasions at the same location in Århus Bay, Denmark. One objective was to analyse the duration of post-release mortality and the magnitude of this mortality. In 2003 a group called Large turbot (17.1 cm total length (L T)) and a group called Intermediate (L T = 11.8 cm) were released, and in 2004 two similar-sized groups called Naive and Conditioned (L T = 9.8 cm) were released. The Conditioned differed from the Naive turbot by being transferred to enclosures at the release location six days prior to the actual release. This experiment was performed to investigate whether such a conditioning period had a positive effect on the survival and hence the success of the stocking. All the groups released were monitored daily until day 8, using a juvenile flatfish-trawl to recapture the fish. The catches were analyzed on the basis of a normal distribution approximation method, founded in diffusion theory, from which daily abundance of the released fish and hence post-release mortality could be estimated. The group of Large turbot suffered negligible post-release mortality, but for the Conditioned, Naive and Intermediate groups the loss varied between 34 and 66% d - 1 . The mortality for the Conditioned group was found to be half that of the Naive turbot released simultaneously. The period of high post-release mortality was estimated to be restricted to three days after release. The only active predators observed in the area were birds. Besides estimating mortality the diffusion model provides an estimate on the catchability of the released turbot when fished with a juvenile flatfish-trawl. Catchabilities varied between 38 and 52% for all releases except for the 17 cm sized turbot released, where catchability was only 12%. The feeding performance of the released fish was also analysed and compared with that of wild fish caught at the

  19. The Greenland Ice Mapping Project

    NASA Astrophysics Data System (ADS)

    Joughin, I.; Smith, B.; Howat, I. M.; Moon, T. A.; Scambos, T. A.

    2015-12-01

    Numerous glaciers in Greenland have sped up rapidly and unpredictably during the first part of the 21st Century. We started the Greenland Ice Mapping Project (GIMP) to produce time series of ice velocity for Greenland's major outlet glaciers. We are also producing image time series to document the advance and retreat of glacier calving fronts and other changes in ice-sheet geometry (e.g., shrinking ice caps and ice shelves). When the project began, there was no digital elevation model (DEM) with sufficient accuracy and resolution to terrain-correct the SAR-derived products. Thus, we also produced the 30-m GIMP DEM, which, aside from improving our processing, is an important product in its own right. Although GIMP focuses on time series, complete spatial coverage for initializing ice sheet models also is important. There are insufficient data, however, to map the full ice sheet in any year. There is good RADARSAT coverage for many years in the north, but the C-band data decorrelate too quickly to measure velocity in the high accumulation regions of the southeast. For such regions, ALOS data usually correlate well, but speckle-tracking estimates at L-band are subject to large ionospheric artifacts. Interferometric phase data are far less sensitive to the effect of the ionosphere, but velocity estimates require results from crossing orbits. Thus, to produce a nearly complete mosaic we used data from multiple sensors, beginning with ERS-1/2 data from the mid 1990s. By using a primarily phase-only solution for much of the interior, we have reduced the velocity errors to ~1-3 m/yr. For the faster moving ice-sheet margin where phase data cannot be unwrapped, we used speckle-tracking data. In particular, we have relied on TerraSAR-X for many fast-moving glaciers because the ionosphere far less affects X-band data. This pan-Greenland velocity map as well as many of the time series would not have been possible without an extensive archive of data collected using six

  20. A Microsatellite Genetic Map of the Turbot (Scophthalmus maximus)

    PubMed Central

    Bouza, Carmen; Hermida, Miguel; Pardo, Belén G.; Fernández, Carlos; Fortes, Gloria G.; Castro, Jaime; Sánchez, Laura; Presa, Pablo; Pérez, Montse; Sanjuán, Andrés; de Carlos, Alejandro; Álvarez-Dios, José Antonio; Ezcurra, Susana; Cal, Rosa M.; Piferrer, Francesc; Martínez, Paulino

    2007-01-01

    A consensus microsatellite-based linkage map of the turbot (Scophthalmus maximus) was constructed from two unrelated families. The mapping panel was derived from a gynogenetic family of 96 haploid embryos and a biparental diploid family of 85 full-sib progeny with known linkage phase. A total of 242 microsatellites were mapped in 26 linkage groups, six markers remaining unlinked. The consensus map length was 1343.2 cM, with an average distance between markers of 6.5 ± 0.5 cM. Similar length of female and male maps was evidenced. However, the mean recombination at common intervals throughout the genome revealed significant differences between sexes, ∼1.6 times higher in the female than in the male. The comparison of turbot microsatellite flanking sequences against the Tetraodon nigroviridis genome revealed 55 significant matches, with a mean length of 102 bp and high sequence similarity (81–100%). The comparative mapping revealed significant syntenic regions among fish species. This study represents the first linkage map in the turbot, one of the most important flatfish in European aquaculture. This map will be suitable for QTL identification of productive traits in this species and for further evolutionary studies in fish and vertebrate species. PMID:18073440

  1. Helmintofauna of turbot Scophthalmus maximus (Linnaeus, 1758) from the southern Baltic Sea including new data.

    PubMed

    Skrzypczak, M; Rolbiecki, L

    2015-01-01

    Turbot Scophthalmus maximus (Linnaeus, 1758) is a fish belonging to the Pleuronectiformes order. It is commonly observed in waters of the northern Atlantic, and also in the Baltic Sea. As an economically significant species, it is fished on an industrial scale, and also farmed in some European countries. Seventy-two turbots from the Gulf of Gdańsk (26th ICES zone) were examined for parasite presence in the years 2010-2012. The study revealed the presence of the tapeworm Bothriocephalus scorpii (Müller, 1776) and acanthocephalan Corynosoma semerme (Forssell, 1904). The overall (both parasites) prevalence of turbot infection was 100% with a mean intensity of 18.7. C. semerme is a parasite which has not been noted so far in turbot from the southern Baltic. The presence of C. semerme in turbot was emphasized in the context of possible infection of terrestrial mammals, including humans. PMID:26618593

  2. The peopling of Greenland: further insights from the analysis of genetic diversity using autosomal and X-chromosomal markers.

    PubMed

    Pereira, Vania; Tomas, Carmen; Sanchez, Juan J; Syndercombe-Court, Denise; Amorim, António; Gusmão, Leonor; Prata, Maria João; Morling, Niels

    2015-02-01

    The peopling of Greenland has a complex history shaped by population migrations, isolation and genetic drift. The Greenlanders present a genetic heritage with components of European and Inuit groups; previous studies using uniparentally inherited markers in Greenlanders have reported evidence of a sex-biased, admixed genetic background. This work further explores the genetics of the Greenlanders by analysing autosomal and X-chromosomal data to obtain deeper insights into the factors that shaped the genetic diversity in Greenlanders. Fourteen Greenlandic subsamples from multiple geographical settlements were compared to assess the level of genetic substructure in the Greenlandic population. The results showed low levels of genetic diversity in all sets of the genetic markers studied, together with an increased number of X-chromosomal loci in linkage disequilibrium in relation to the Danish population. In the broader context of worldwide populations, Greenlanders are remarkably different from most populations, but they are genetically closer to some Inuit groups from Alaska. Admixture analyses identified an Inuit component in the Greenlandic population of approximately 80%. The sub-populations of Ammassalik and Nanortalik are the least diverse, presenting the lowest levels of European admixture. Isolation-by-distance analyses showed that only 16% of the genetic substructure of Greenlanders is most likely to be explained by geographic barriers. We suggest that genetic drift and a differentiated settlement history around the island explain most of the genetic substructure of the population in Greenland.

  3. Development of an inactivated iridovirus vaccine against turbot viral reddish body syndrome

    NASA Astrophysics Data System (ADS)

    Fan, Tingjun; Hu, Xiuzhong; Wang, Liyan; Geng, Xiaofen; Jiang, Guojian; Yang, Xiuxia; Yu, Miaomiao

    2012-03-01

    Turbot ( Scophthalmus maximus L.) reddish body iridovirus (TRBIV) was propagated in turbot fin cells (TF cells) and inactivated as the TRBIV vaccine with its protection efficiency evaluated in this study. TF cells were cultured in 10% bovine calf serum (BCS)-containing MEM medium (pH7.0) at 22°C, in which TRBIV propagated to a titer as high as 105.6 TCID50 mL-1. The TRBIV was inactivated with 0.1% formalin and formulated with 0.5% aluminum hydroxide. The inactivated vaccine caused neither cytopathogenic effect (CPE) on TF cells nor pathogenic effect on turbots. After being administered with the vaccine twice via muscle injection, the turbot developed high-tittered TRBIV neutralizing antibodies in a dose-dependent manner. The vaccine protected the turbot from dying with an immunoprotection rate of 83.3% as was determined via subcutaneous vaccination in the laboratory and 90.5% via bath vaccination in turbot farms, respectively. The inactivated vaccine was very immunogenic, efficiently preventing turbot from death. It holds the potential of being applied in aquaculture.

  4. Turbot (Scophthalmus maximus) vs. VHSV (Viral Hemorrhagic Septicemia Virus): A Review

    PubMed Central

    Pereiro, Patricia; Figueras, Antonio; Novoa, Beatriz

    2016-01-01

    Turbot (Scophthalmus maximus) is a very valuable fish species both in Europe and China. The culture of this flatfish is well-established but several bacteria, viruses, and parasites can produce mortality or morbidity episodes in turbot farms. Viral Hemorrhagic Septicemia Virus (VHSV) is one of the most threatening pathogens affecting turbot, because neither vaccines nor treatments are commercially available. Although the mortality in the turbot farms is relatively low, when this virus is detected all the stock have to be destroyed. The main goals that need to be improved in order to reduce the incidence of this disease is to know what are the strategies or molecules the host use to fight the virus and, in consequence, try to potentiate this response using different ways. Certain molecules can be selected as potential antiviral treatments because of their high protective effect against VHSV. On the other hand, the use of resistance markers for selective breeding is one of the most attractive approaches. This review englobes all the investigation concerning the immune interaction between turbot and VHSV, which until the last years was very scarce, and the knowledge about VHSV-resistance markers in turbot. Nowadays, the availability of abundant transcriptomic information and the recent sequencing of the turbot genome open the door to a more exhaustive and profuse investigation in these areas. PMID:27303308

  5. Turbot (Scophthalmus maximus) vs. VHSV (Viral Hemorrhagic Septicemia Virus): A Review.

    PubMed

    Pereiro, Patricia; Figueras, Antonio; Novoa, Beatriz

    2016-01-01

    Turbot (Scophthalmus maximus) is a very valuable fish species both in Europe and China. The culture of this flatfish is well-established but several bacteria, viruses, and parasites can produce mortality or morbidity episodes in turbot farms. Viral Hemorrhagic Septicemia Virus (VHSV) is one of the most threatening pathogens affecting turbot, because neither vaccines nor treatments are commercially available. Although the mortality in the turbot farms is relatively low, when this virus is detected all the stock have to be destroyed. The main goals that need to be improved in order to reduce the incidence of this disease is to know what are the strategies or molecules the host use to fight the virus and, in consequence, try to potentiate this response using different ways. Certain molecules can be selected as potential antiviral treatments because of their high protective effect against VHSV. On the other hand, the use of resistance markers for selective breeding is one of the most attractive approaches. This review englobes all the investigation concerning the immune interaction between turbot and VHSV, which until the last years was very scarce, and the knowledge about VHSV-resistance markers in turbot. Nowadays, the availability of abundant transcriptomic information and the recent sequencing of the turbot genome open the door to a more exhaustive and profuse investigation in these areas. PMID:27303308

  6. Greenland Ice Flow

    NASA Video Gallery

    Greenland looks like a big pile of snow seen from space using a regular camera. But satellite radar interferometry helps us detect the motion of ice beneath the snow. Ice starts flowing from the fl...

  7. Dietary protein requirement of juvenile turbot ( Scophthalmus maximus Linnaeus)

    NASA Astrophysics Data System (ADS)

    Liu, Xingwang; Mai, Kangsen; Liufu, Zhiguo; Ai, Qinghui

    2015-04-01

    The dietary protein requirement of juvenile turbot (initial average weight, 38.2 g ± 0.1 g) reared indoor in aerated aquaria was determined in this study. Five energy equal experimental diets were formulated with fish meal as protein source, which contained different concentrations of protein (47.2%, 51.0%, 54.6%, 59.3% and 63.6% of dry diet). Three groups of fish with 18 individuals in each, were cultured in 300-L tanks and fed twice a day for 8 weeks. During culture, temperature was controlled between 15.0 and 18.0°C, salinity was controlled between 28.5 and 32.0, acidity was controlled between pH7.8 and pH8.5, and ammonia nitrogen was maintained below 0.03 mg L-1 and dissolved oxygen was maintained about 7 mg L-1. Results showed that the growth of fish was significantly affected by dietary protein content ( P < 0.05). Specific growth rate ( SGR) of turbot increased when dietary protein content varied between 47.2% and 51.0% ( P < 0.05), and then kept stable when dietary protein content was higher than 51.0%. Fish which were fed the diet containing 63.6% protein showed the highest SGR while those fed the diet containing 59.3% protein showed the highest feed efficiency rate. No significant difference of feed intake and protein efficiency ratio was found among experimental diets ( P > 0.05). Broken-line regression analysis of SGR showed that the optimal dietary protein requirement of turbot was about 57.0%.

  8. Flying Low over Southeast Greenland

    NASA Video Gallery

    Few of us ever get to see Greenland's glaciers from 500 meters above the ice. But in this video — recorded on April 9,2013 in southeast Greenland using a cockpit camera installed and operated by ...

  9. Heritability and genetic correlation of survival in turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Wang, Xin'an; Ma, Aijun; Huang, Zhihui; Zhou, Zhou

    2010-11-01

    We analyzed the survival data of the offspring from 21 sires and 42 dams of turbot. The results show that the cumulative survival rates for turbot from 2 to 18 months range from 17.5% to 28.5%; main mortality occurred during months 2-5; and the highest survival rates of families were 97.9%, 98.8%, 99.4%, 99.7% during months 2-5, 5-6, 6-8, 8-11, and 11-18, respectively, and 99.5%, being 53.5%, 23.8%, 19.5%, 14.9%, and 13.2% higher, respectively, than the mean values in each period. In all periods, the estimated heritabilities for survival were very low without significant difference from zero ( P≫0.05) (values ranged from 0.06 to 0.12), indicating low additive genetic effects. The genetic correlations of survival among families in different periods were all positive, but low in magnitude (values range from 0.03 to 0.31). Genetic correlations between long-term survival and other periods’ survival had negative values (-0.06 and -0.15) and three positive values (0.16, 0.12 and 0.14). Genetic correlations between survival and weight were all positive, except for survival at months 2-5 and weight at 18 months, which was not significantly negative (-0.18).

  10. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life.

    PubMed

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-06-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot.

  11. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life

    PubMed Central

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A.; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G.; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-01-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot. PMID:26951068

  12. Host range susceptibility of Enterococcus sp. strains isolated from diseased turbot: possible routes of infection.

    PubMed Central

    Romalde, J L; Magariños, B; Nuñez, S; Barja, J L; Toranzo, A E

    1996-01-01

    Experiments were conducted to assess the pathogenicity of Enterococcus sp. strains isolated from diseased turbot for several fish species (turbot, salmon, trout, and seabream), as well as for mice. The intraperitoneal injection assays indicated that the tested strains showed host specificity for turbot, with a high degree of virulence (50% lethal dose of 10(4) cells per g of fish). The Spanish Enterococcus sp. isolates were nonpathogenic for the other fish species studied and for mice. The possible routes of infection were determined by bath exposure (with and without prior abrasion of the skin) and by intragastric inoculations with food and feces contaminated with the pathogen. The bath challenges indicated that the Enterococcus isolates were able to overcome the defense mechanisms present on the surface of the turbot only if the skin was abraded prior to the exposure. The antibacterial activities of components of a glycoprotein nature present in the turbot skin mucus are probably responsible in part for the resistance in noninjured fish to infection. On the other hand, we demonstrated the capacity of this pathogen to overcome adverse conditions in the stomachs of fish when associated with food or fecal material, since it is able to establish an infective state and to produce mortalities after 16 to 20 days postingestion. From all of these findings, we can conclude that horizontal transmissions through water and the fecal-oral route are the main avenues of infection of turbot streptococcosis. PMID:8593061

  13. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life.

    PubMed

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-06-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot. PMID:26951068

  14. An early Holocene Greenland whale from Melville Bugt, Greenland

    NASA Astrophysics Data System (ADS)

    Bennike, Ole

    2008-01-01

    Radiocarbon age determination of a Greenland whale ( Balaena mysticetus) vertebra from Melville Bugt in northwestern Greenland yields an age of 9259-8989 cal yr BP. The margin of the Greenland Ice Sheet in Melville Bugt was situated behind its AD 1950-2000 position in the early Holocene, at a similar position to that being reached following rapid retreat in recent years. Such an early deglaciation of areas close to the Greenland Ice Sheet is unusual. This probably reflects the unique glaciological setting resulting from the narrow fringe of ice-free islands and peninsulas and offshore waters with deep areas that characterize this part of Greenland. The timing of Greenland Ice Sheet retreat to its present margin varies significantly around Greenland.

  15. Glaciers of Greenland

    USGS Publications Warehouse

    Williams, Richard S.; Ferrigno, Jane G.

    1995-01-01

    Landsat imagery, combined with aerial photography, sketch maps, and diagrams, is used as the basis for a description of the geography, climatology, and glaciology, including mass balance, variation, and hazards, of the Greenland ice sheet and local ice caps and glaciers. The Greenland ice sheet, with an estimated area of 1,736,095+/-100 km2 and volume of 2,600,000 km3, is the second largest glacier on the planet and the largest relict of the Ice Age in the Northern Hemisphere. Greenland also has 48,599+/-100 km2 of local ice caps and other types of glaciers in coastal areas and islands beyond the margin of the ice sheet.

  16. UNIT, ALASKA.

    ERIC Educational Resources Information Center

    Louisiana Arts and Science Center, Baton Rouge.

    THE UNIT DESCRIBED IN THIS BOOKLET DEALS WITH THE GEOGRAPHY OF ALASKA. THE UNIT IS PRESENTED IN OUTLINE FORM. THE FIRST SECTION DEALS PRINCIPALLY WITH THE PHYSICAL GEOGRAPHY OF ALASKA. DISCUSSED ARE (1) THE SIZE, (2) THE MAJOR LAND REGIONS, (3) THE MOUNTAINS, VOLCANOES, GLACIERS, AND RIVERS, (4) THE NATURAL RESOURCES, AND (5) THE CLIMATE. THE…

  17. Q Fever in Greenland

    PubMed Central

    Svendsen, Claus Bo; Christensen, Jens Jørgen; Bundgaard, Henning; Vindfeld, Lars; Christiansen, Claus Bohn; Kemp, Michael; Villumsen, Steen

    2010-01-01

    We report a patient with Q fever endocarditis in a settlement in eastern Greenland (Isortoq, Ammassalik area). Likely animal sources include sled dogs and seals. Q fever may be underdiagnosed in Arctic areas but may also represent an emerging infection. PMID:20202433

  18. Population ecology of turbot and brill: What can we learn from two rare flatfish species?

    NASA Astrophysics Data System (ADS)

    van der Hammen, Tessa; Poos, Jan Jaap; van Overzee, Harriët M. J.; Heessen, Henk J. L.; Magnusson, Arni; Rijnsdorp, Adriaan D.

    2013-11-01

    Turbot and brill are widely distributed in the Northeast Atlantic but occur at low abundance. They are ecologically very similar and closely related. The low abundance and the similarities make them particularly interesting to study the population dynamics because it raises the questions how the populations can sustain themselves at low abundances and how turbot and brill avoid strong interspecific competition. Knowledge of both species is hampered by lack of analysed data. The main objective of this study is therefore to increase the knowledge of turbot and brill and in particular to compare the two species in order to address the above questions. Based on biological samples collected in the North Sea, we calculated seasonal von Bertalanffy growth parameters, maturity ogives, monthly gonado-somatic indices (GSI) and condition factors (Fulton's K) and indices of inter- and intraspecific mean crowding and compared the results for turbot and brill. The main differences between the two species were found in their spawning period, with brill having a more protracted spawning period. Brill also showed an earlier peak in their GSI values, suggesting an earlier start of their spawning period. The mean crowding showed that interspecific competition was lower than intraspecific competition. The exploitation pattern was also studied. Turbot and brill are exploited as a bycatch species in the mixed demersal fishery. We found that productivity is highest in areas where the maximum temperature is close to the optimal temperature for growth (16-18 °C) and landings decrease where salinity falls below ~ 5 psu (turbot) and ~ 15 psu (brill). Recent fishing mortality rates of North Sea turbot are around 0.5-0.7, but there is no indication that recruitment is impaired at low levels of spawning stock biomass. We conclude that although both species have similar ecological characteristics, differences may reduce inter-specific competition.

  19. Fine Mapping and Evolution of the Major Sex Determining Region in Turbot (Scophthalmus maximus)

    PubMed Central

    Taboada, Xoana; Hermida, Miguel; Pardo, Belén G.; Vera, Manuel; Piferrer, Francesc; Viñas, Ana; Bouza, Carmen; Martínez, Paulino

    2014-01-01

    Fish sex determination (SD) systems are varied, suggesting evolutionary changes including either multiple evolution origins of genetic SD from nongenetic systems (such as environmental SD) and/or turnover events replacing one genetic system by another. When genetic SD is found, cytological differentiation between the two members of the sex chromosome pair is often minor or undetectable. The turbot (Scophthalmus maximus), a valuable commercial flatfish, has a ZZ/ZW system and a major SD region on linkage group 5 (LG5), but there are also other minor genetic and environmental influences. We here report refined mapping of the turbot SD region, supported by comparative mapping with model fish species, to identify the turbot master SD gene. Six genes were located to the SD region, two of them associated with gonad development (sox2 and dnajc19). All showed a high association with sex within families (P = 0), but not at the population level, so they are probably partially sex-linked genes, but not SD gene itself. Analysis of crossovers in LG5 using two families confirmed a ZZ/ZW system in turbot and suggested a revised map position for the master gene. Genetic diversity and differentiation for 25 LG5 genetic markers showed no differences between males and females sampled from a wild population, suggesting a recent origin of the SD region in turbot. We also analyzed associations with markers of the most relevant sex-related linkage groups in brill (S. rhombus), a closely related species to turbot; the data suggest that an ancient XX/XY system in brill changed to a ZZ/ZW mechanism in turbot. PMID:25106948

  20. Consolidation of the genetic and cytogenetic maps of turbot (Scophthalmus maximus) using FISH with BAC clones.

    PubMed

    Taboada, Xoana; Pansonato-Alves, Jose C; Foresti, Fausto; Martínez, Paulino; Viñas, Ana; Pardo, Belén G; Bouza, Carmen

    2014-06-01

    Bacterial artificial chromosomes (BAC) have been widely used for fluorescence in situ hybridization (FISH) mapping of chromosome landmarks in different organisms, including a few in teleosts. In this study, we used BAC-FISH to consolidate the previous genetic and cytogenetic maps of the turbot (Scophthalmus maximus), a commercially important pleuronectiform. The maps consisted of 24 linkage groups (LGs) but only 22 chromosomes. All turbot LGs were assigned to specific chromosomes using BAC probes obtained from a turbot 5× genomic BAC library. It consisted of 46,080 clones with inserts of at least 100 kb and <5 % empty vectors. These BAC probes contained gene-derived or anonymous markers, most of them linked to quantitative trait loci (QTL) related to productive traits. BAC clones were mapped by FISH to unique marker-specific chromosomal positions, which showed a notable concordance with previous genetic mapping data. The two metacentric pairs were cytogenetically assigned to LG2 and LG16, and the nucleolar organizer region (NOR)-bearing pair was assigned to LG15. Double-color FISH assays enabled the consolidation of the turbot genetic map into 22 linkage groups by merging LG8 with LG18 and LG21 with LG24. In this work, a first-generation probe panel of BAC clones anchored to the turbot linkage and cytogenetical map was developed. It is a useful tool for chromosome traceability in turbot, but also relevant in the context of pleuronectiform karyotypes, which often show small hardly identifiable chromosomes. This panel will also be valuable for further integrative genomics of turbot within Pleuronectiformes and teleosts, especially for fine QTL mapping for aquaculture traits, comparative genomics, and whole-genome assembly.

  1. Egg production of turbot, Scophthalmus maximus, in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Nissling, Anders; Florin, Ann-Britt; Thorsen, Anders; Bergström, Ulf

    2013-11-01

    In the brackish water Baltic Sea turbot spawn at ~ 6-9 psu along the coast and on offshore banks in ICES SD 24-29, with salinity influencing the reproductive success. The potential fecundity (the stock of vitellogenic oocytes in the pre-spawning ovary), egg size (diameter and dry weight of artificially fertilized 1-day-old eggs) and gonad dry weight were assessed for fish sampled in SD 25 and SD 28. Multiple regression analysis identified somatic weight, or total length in combination with Fulton's condition factor, as main predictors of fecundity and gonad dry weight with stage of maturity (oocyte packing density or leading cohort) as an additional predictor. For egg size, somatic weight was identified as main predictor while otolith weight (proxy for age) was an additional predictor. Univariate analysis using GLM revealed significantly higher fecundity and gonad dry weight for turbot from SD 28 (3378-3474 oocytes/g somatic weight) compared to those from SD 25 (2343 oocytes/g somatic weight), with no difference in egg size (1.05 ± 0.03 mm diameter and 46.8 ± 6.5 μg dry weight; mean ± sd). The difference in egg production matched egg survival probabilities in relation to salinity conditions suggesting selection for higher fecundity as a consequence of poorer reproductive success at lower salinities. This supports the hypothesis of higher size-specific fecundity towards the limit of the distribution of a species as an adaptation to harsher environmental conditions and lower offspring survival probabilities. Within SD 28 comparisons were made between two major fishing areas targeting spawning aggregations and a marine protected area without fishing. The outcome was inconclusive and is discussed with respect to potential fishery induced effects, effects of the salinity gradient, effects of specific year-classes, and effects of maturation status of sampled fish.

  2. Tectonic events in Greenland

    NASA Astrophysics Data System (ADS)

    Dahl-Jensen, T.; Voss, P.; Larsen, T.; Pinna, L.

    2012-12-01

    In Greenland a station separation of around 400km mean that many earthquakes are only detected on one or two stations. The development of the seismic monitoring have gone from having only three seismic stations in Greenland up to the late 1990'ies, till today where there are 18 permanent stations. All stations are equipped with broadband sensors and all of the permanent stations transmit data in real time. The recent major improvement of the seismic monitoring is performed by the Greenland ice sheet monitoring network (GLISN, http://glisn.info). The primary goal of GLISN is to provide broadband seismic data for the detection of glacial earthquakes. GLISN is now fully implemented with Iridium real time data transfer is in operation at five stations. In the Ammassalik region in Southeast Greenland, where small earthquakes often are felt, data from a temporary additional station has been utilized for a study covering 9 months in 2008/9. In this period 62 local earthquakes have been analyzed and re-located. Some of the events had formerly been located from distant stations by using a universal earth model. The result of this localization was a scattered distribution of the events in the region. The locations have now been improved by using a local earth model along with phase readings from two local stations not previously included; ANG in Tasiilaq and ISOG in Isortoq. From relocating the events two zones with a higher degree of seismicity than in the rest of the region are observed. The first zone is located by felsic intrusions. The second zone is at the boundary between the Archaean Craton and the Ammasalik region where reworked Archaean gneisses are dominating the geology. During the analysis it was observed that the additional information from the local stations are of great importance for the result. Active broad band stations in Greenland

  3. The Wegener Memorial Expedition to the Greenland Caledonides

    NASA Astrophysics Data System (ADS)

    Stüwe, Kurt; Piller, Werner

    2014-05-01

    2012 marked the 100 anniversary of the publication of Alfred Wegeners book: 'Die Entstehung der Kontinente' - which is often hailed as the discovery of continental drift theory in the advent of plate tectonics. Wegener was later appointed as professor for geophysics at the University of Graz in Austria - in part for this discovery. He held this position until his death in Greenland in 1930. In honor of the hundredth anniversary of the 1912 milestone publication, the University of Graz in Austria stages an expedition to Greenland in the spirit of Alfred Wegener, supported by the Austrian Academy of Sciences. The expedition aims predominantly to unravel secrets of the Caledonides of Northeastern Greenland using an extensive sampling program to some of the least explored corners of the orogenic belt. Particular emphasis will be placed on the Hager Bjerg allochthon and its relationship to the hanging wall and footwall units. The expedition will use the unparalleled flexibility of small aircraft that will be piloted by experienced Alaskan bush pilots and brought to Greenland from Alaska for this purpose.

  4. Regional Observations of Alaska Glacier Dynamics

    NASA Astrophysics Data System (ADS)

    Burgess, E. W.; Forster, R. R.; Hall, D. K.

    2010-12-01

    Alaska glaciers contribute more to sea level rise than any other glacierized mountain region in the world. Alaska is loosing ~84 Gt of ice annually, which accounts for ~0.23 mm/yr of SLR (Luthcke et al., 2008). Complex glacier flow dynamics, frequently related to tidewater environments, is the primary cause of such rapid mass loss (Larsen et al., 2007). Indirect observations indicate these complex flow dynamics occur on many glaciers throughout Alaska, but no comprehensive velocity measurements exist. We are working to measure glacier surface velocities throughout Alaska using synthetic aperture radar (SAR) offset tracking. This work focuses on the Seward/Malaspina, Bering, Columbia, Kaskawulsh, and Hubbard Glaciers and uses a MODIS land surface temperature "melt-day" product (Hall et al., 2006, 2008) to identify potential links between velocity variability and summertime temperature fluctuations. Hall, D., R. Williams Jr., K. Casey, N. DiGirolamo, and Z. Wan (2006), Satellite-derived, melt-season surface temperature of the Greenland Ice Sheet (2000-2005) and its relationship to mass balance, Geophysical Research Letters, 33(11). Hall, D., J. Box, K. Casey, S. Hook, C. Shuman, and K. Steffen (2008), Comparison of satellite-derived and in-situ observations of ice and snow surface temperatures over Greenland, Remote Sensing of Environment, 112(10), 3739-3749. Larsen, C. F., R. J. Motyka, A. A. Arendt, K. A. Echelmeyer, and P. E. Geissler (2007), Glacier changes in southeast Alaska and northwest British Columbia and contribution to sea level rise, J. Geophys. Res. Luthcke, S., A. Arendt, D. Rowlands, J. McCarthy, and C. Larsen (2008), Recent glacier mass changes in the Gulf of Alaska region from GRACE mascon solutions, Journal of Glaciology, 54(188), 767-777.

  5. Gravity in Greenland

    SciTech Connect

    Hughes, R.J.; Goldman, T.; Nieto, M.M.

    1988-01-01

    Preliminary results of the test of the Newtonian Law of Gravitation conducted by Ander et al., in a borehole in the Greenland ice-cap were reported at this meeting. In this paper we consider the interpretations of these results in terms of a non-Newtonian component of gravity, and compare them with the results of other geophysical inverse-square law tests. 8 refs.

  6. Chemokine receptor CXCR3 in turbot (Scophthalmus maximus): cloning, characterization and its responses to lipopolysaccharide.

    PubMed

    Chen, Yadong; Zhou, Shuhong; Jiang, Zhiqiang; Wang, Xiuli; Liu, Yang

    2016-04-01

    Chemokine (C-X-C motif) receptor 3, a member of the G protein-coupled receptors superfamily, regulates the responses of many immune responses. In this experiment, we cloned and characterized the cDNA of CXCR3 in Scophthalmus maximus (turbot). A 5'-UTR of 216-bp, a 259-bp 3'-UTR with a poly (A) tail and a 1089-bp CDS encoding 362 amino acids form the cDNA of CXCR3, which is 1564-bp long. Phylogenetic analyses indicated that turbot CXCR3 shared a high similarity with other CXCR3s and shared more similarity with CXCR5 than the other subfamilies of chemokines. The CXCR3 protein in turbot showed the highest similarity with the CXCR3b from rainbow trout (44.5%), which indicated that this CXCR3 gene/protein may be a CXCR3b isoform. Quantitative real-time PCR analysis showed that CXCR3 transcripts were constitutively expressed in all the tissues of the non-injected turbot used in this study, with the highest expression occurring in blood. Several immune-related tissues of fish, such as the spleen, head kidney, liver and blood, tissues, which were abundant of lymphocyte, were investigated in this study. CXCR3 gene was expressed at the highest level in blood than the other tested tissues. The injection experiment suggested that the CXCR3 expression level after LPS injection was significantly up-regulated in all immune-related tissues in turbot. These results improve our understanding of the functions of CXCR3 in the turbot immune response. PMID:26585996

  7. Atuarfitsialak: Greenland's Cultural Compatible Reform

    ERIC Educational Resources Information Center

    Wyatt, Tasha R.

    2012-01-01

    In 2002, Greenlandic reform leaders launched a comprehensive, nation-wide reform to create culturally compatible education. Greenland's reform work spans the entire educational system and includes preschool through higher education. To assist their efforts, reform leaders adopted the Standards for Effective Pedagogy developed at the Center for…

  8. Entering uncharted waters: Long-term dynamics of two data limited fish species, turbot and brill, in the North Sea

    NASA Astrophysics Data System (ADS)

    Kerby, Tina K.; Cheung, William W. L.; van Oosterhout, Cock; Engelhard, Georg H.

    2013-11-01

    In the North Sea, turbot (Scophthalmus maximus) and brill (Scophthalmus rhombus) represent highly valuable species in commercial fisheries. Still, available data for both species are limited, making stock assessment difficult. Long-term fisheries data have the potential to improve the understanding of stock dynamics such as long-term distribution changes or development in species' abundances. Historical British otter trawler lpue (landings-per-unit-effort) data from 1923 to 2009, and at the spatial scale of ICES rectangles, revealed that the distribution patterns of turbot and brill were different for most of the 20th century and only became similar in the recent decade. Further, between the 1920s and 1960s, turbot was commonly caught in the northern North Sea and in particular on Turbot Bank, at that time a turbot hotspot off the east coast of Scotland. Within a short time period turbot nearly disappeared from this region. Brill, in contrast, revealed a stable distribution in the southern and central North Sea with a slow expansion into the central North Sea. We used survey cpue (catch-per-unit-effort) from the International Bottom Trawl Survey (IBTS; 1970-2009) and the Beam Trawl Survey (BTS; 1985-2009), as well as British otter trawler lpue, as proxies for the abundance of adult turbot and brill. Commercial lpue suggested for brill and turbot a long-term decrease in abundance. IBTS cpue suggested an increase in abundance for turbot, but this was not confirmed by the BTS. For brill, both surveys did not show a clear trend.

  9. SeaWinds - Greenland

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The frequent coverage provided by NASA's SeaWinds instrument on the QuikScat satellite provides unprecedented capability to monitor daily and seasonal changes in the key melt zones of Greenland, which is covered with a thick ice sheet that resulted from snow accumulating over tens of thousands of years. The thickness of the snow layers reveals details about the past global climate, and comparing snow accumulation and snow melting can provide insight into climate change and global warming. In particular, the extent of summer melting of snow in Greenland is considered a sensitive indicator of global change.

    Earlier scatterometer data has suggested that Greenland has experienced significantly more melting in recent years. This figure compares the melting observed over 15 days during July 1999 in Greenland. The red areas around the central blue and white areas are the main melt zones and have lower radar back scatter because of water on the surface that saturates the surface snow. As the days warm up, the melt extent dramatically increases. Comparing this data with computer models and past scatterometer data will help scientists evaluate the inter-annual variability of the melting as a step toward understanding potential climate change.

    The world's large ice sheets in Greenland and Antarctica act as vast storehouses of freshwater. Summer season melting releases large quantities of freshwater into the ocean, and year-to-year variations can have a significant impact on global sea level. Furthermore, long-term changes in the patterns and extent of melting on the large ice sheets reflect the effects of climate variability; thus Greenland is considered a sensitive indicator of global warming.

    Satellite microwave radars are extremely sensitive to melting and can provide the only effective means of accurately measuring the year-round picture of the extent and variability in ice sheet melting. Daily mean images were produced from QuikScat data collected over the

  10. Adventure Learning @ Greenland

    NASA Astrophysics Data System (ADS)

    Miller, B. G.; Cox, C. J.; Hougham, J.; Walden, V. P.; Eitel, K.; Albano, A.

    2013-12-01

    Teaching the general public and K-12 communities about scientific research has taken on greater importance as climate change increasingly impacts the world we live in. Science researchers and the educational community have a widening responsibility to produce and deliver curriculum and content that is timely, scientifically sound and engaging. To address this challenge, in the summer of 2012 the Adventure Learning @ Greenland (AL@GL) project, a United States' National Science Foundation (NSF) funded initiative, used hands-on and web-based climate science experiences for high school students to promote climate and science literacy. This presentation will report on an innovative approach to education and outreach for environmental science research known as Adventure Learning (AL). The purpose of AL@GL was to engage high school students in the US, and in Greenland, in atmospheric research that is being conducted in the Arctic to enhance climate and science literacy. Climate and science literacy was explored via three fundamental concepts: radiation, the greenhouse effect, and climate vs. weather. Over the course of the project, students in each location engaged in activities and conducted experiments through the use of scientific instrumentation. Students were taught science research principles associated with an atmospheric observatory at Summit Station, Greenland with the objective of connecting climate science in the Arctic to student's local environments. Summit Station is located on the Greenland Ice Sheet [72°N, 38°W, 3200 m] and was the primary location of interest. Approximately 35 students at multiple locations in Idaho, USA, and Greenland participated in the hybrid learning environments as part of this project. The AL@GL project engaged students in an inquiry-based curriculum with content that highlighted a cutting-edge geophysical research initiative at Summit: the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at

  11. Greenland Glacier Albedo Variability

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The program for Arctic Regional Climate Assessment (PARCA) is a NASA-funded project with the prime goal of addressing the mass balance of the Greenland ice sheet. Since the formal initiation of the program in 1995, there has been a significant improvement in the estimates of the mass balance of the ice sheet. Results from this program reveal that the high-elevation regions of the ice sheet are approximately in balance, but the margins are thinning. Laser surveys reveal significant thinning along 70 percent of the ice sheet periphery below 2000 m elevations, and in at least one outlet glacier, Kangerdlugssuaq in southeast Greenland, thinning has been as much as 10 m/yr. This study examines the albedo variability in four outlet glaciers to help separate out the relative contributions of surface melting versus ice dynamics to the recent mass balance changes. Analysis of AVHRR Polar Pathfinder albedo shows that at the Petermann and Jakobshavn glaciers, there has been a negative trend in albedo at the glacier terminus from 1981 to 2000, whereas the Stor+strommen and Kangerdlugssuaq glaciers show slightly positive trends in albedo. These findings are consistent with recent observations of melt extent from passive microwave data which show more melt on the western side of Greenland and slightly less on the eastern side. Significance of albedo trends will depend on where and when the albedo changes occur. Since the majority of surface melt occurs in the shallow sloping western margin of the ice sheet where the shortwave radiation dominates the energy balance in summer (e.g. Jakobshavn region) this region will be more sensitive to changes in albedo than in regions where this is not the case. Near the Jakobshavn glacier, even larger changes in albedo have been observed, with decreases as much as 20 percent per decade.

  12. Pharmacokinetics and acetylation of sulfamethoxazole in turbot Scophthalmus maximus after intravascular administration

    NASA Astrophysics Data System (ADS)

    Chang, Zhiqiang; Liu, Fei; Lian, Chun'ang; Zhai, Qianqian; Li, Jian

    2016-07-01

    The pharmacokinetic profiles and sulfamethoxazole (SMX) acetylation process in turbot reared at 18°C were investigated. Either SMX (parent drug) or its acetylized metabolite, N4-acetylsulfamethoxazole (AcSMX), was administered intravascularly to turbot at a dosage of 50 mg/kg BW. Serum concentrations of the parent drug and its metabolite were both measured by HPLC, and the changes in concentration over time were analyzed in two- and non-compartment models because SMX treatment produced multiple peaks. The results demonstrated that the elimination half-life of the parent drugs, SMX and AcSMX, were 159.2 and 5.9 h, respectively. The apparent volume of distribution was 0.2 and 0.8 L/kg, and the clearance was 0.038 and 0.222 L/(h·kg), for SMX and AcSMX, respectively. SMX acetylation in turbot was 2.8%, and the deacetylation of AcSMX was 0.2%. These findings may be useful in optimizing SMX dosage regimens in turbot aquaculture.

  13. Enhancing the culturability of bacteria from the gastrointestinal tract of farmed adult turbot Scophthalmus maximus

    NASA Astrophysics Data System (ADS)

    Xing, Mengxin; Hou, Zhanhui; Qu, Yanmei; Liu, Bin

    2014-03-01

    Eighteen agar media were tested for the culture of gut-associated bacteria from farmed adult turbot ( Scophthalmus maximus), including 16 agar media with or without 1% gastrointestinal (GI) supernatant, or with 2% or 4% GI supernatant. A total of 1 711 colonies were analyzed and 24 operational taxonomic units (OTUs) were identified. The greatest bacterial diversity was isolated on Zobell 2216E/Zobell 2216E+ agar media, whereas MRS/MRS+ agar media produced a low diversity of colonies. Agar media with GI supernatant (1%, 2%, or 4%) showed increased diversity and yielded different profiles of OTUs from the corresponding original media, suggesting that GI supernatant provides substances that enhance the culture efficiency of bacteria from the turbot GI tract. The large majority of the colonies (82%) were γ-Proteobacteria, whereas 15.6% and 2.4% of colonies were Firmicutes and Actinobacteria, respectively. At the genus level, 49.4% of all colonies were assigned to Vibrio. Other potential pathogens, including Pseudomonas, Photobacterium, and Enterobacter, and potential probiotics, including Bacillus, Paenibacillus, and Pseudomonas, were also isolated on agar media. Most cultured bacteria belonged to species that were first described in the turbot GI tract. The impact of these species on turbot physiology and health should be investigated further.

  14. Morphological, immunohistochemical and ultrastructural characterization of the skin of turbot (Psetta maxima L.).

    PubMed

    Faílde, L D; Bermúdez, R; Vigliano, F; Coscelli, G A; Quiroga, M I

    2014-10-01

    This study was undertaken to identify the normal morphologic, immunohistochemical and ultrastructural features of skin of the turbot (Psetta maxima L.). In the turbot skin, three morphologically distinct layers were identified: epidermis, dermis and hypodermis. The epidermis was non-keratinizing, stratified squamous epithelium that varies in thickness from 5 to 14 cells and 60 to 100μm in size. Goblet cells were seen randomly distributed between malpighian cells in the epidermal layer. These mucous cells were mainly located in the upper third of the epidermis and displayed a spherical to elongated morphology. Dermis was divided in two well-differentiated layers, the superficial stratum laxum and the deeper stratum compactum. Hypodermis was a loose layer mainly composed by adipocytes but we could observe variable amounts of fibroblast, collagen and blood vessels. In turbot two pigmentary layers could be identified: the pigmentary layer of dermis was located between basement membrane and dermis and the pigmentary layer of hypodermis immediately above the muscular layer. Three different types of chromatophores were present: melanophores, iridophores and xanthophores. The main differences observed between groups of fish with different colouration were in the amount of melanophores and xanthophores. The purpose of this article is to provide an overview of normal cutaneous biology prior to consideration of specific cutaneous alterations and diseases in turbot.

  15. Fast Real-Time PCR assay for detection of Tetramicra brevifilum in cultured turbot.

    PubMed

    Alonso, Mercedes; Lago, Fátima C; Gómez-Reino, María; Fernández, Jacobo; Martín, Iris; Vieites, Juan M; Espiñeira, Montserrat

    2013-03-01

    Global aquaculture production of turbot has rapidly increased worldwide in the last decade and it is expected to have even bigger growth in the next years due to new farms operating. The losses caused by pathogen infections have grown at the same time as the production of this species. Parasitological infections are among the main relevant pathologies associated with its culture and produce serious losses in aquaculture, reduce the growth rate in fish and may lead to unmarketable fish due to skeletal muscle abnormalities in cases with high intensity of infection. The microsporidian parasite Tetramicra brevifilum causes severe infections and generates major losses in farmed turbot. Infections are difficult to control due to spore longevity and its direct transmission. To facilitate the infection management, an effective tool for fast detection and identification of T. brevifilum is needed. This study provides a molecular methodology of fast Real-Time PCR for T. brevifilum detection to the aquaculture industry, useful for routine control of T. brevifilum at turbot farms. The method is characterized by its high specificity and sensitivity, and it can be applied to cultured turbot for parasite detection regardless of the life-cycle stage of the pathogen or the infection intensity.

  16. Crustal structure beneath Eastern Greenland

    NASA Astrophysics Data System (ADS)

    Reiche, S.; Thybo, H.; Kaip, G.; Skjoth Bruun, A.; Reid, I.; Chemia, Z.; Greschke, B.

    2011-12-01

    The conjugate Atlantic passive margins of western Norway and eastern Greenland are characterized by the presence of coast-parallel mountain ranges with peak elevations of more than 3.5 km close to Scoresby Sund in Eastern Greenland. Knowledge about crustal thickness and composition below these mountain belts is needed for assessing the isostatic balance of the crust and to gain insight into possible links between crustal composition, rifting history and present-day topography of the North Atlantic Region. However, the acquisition of geophysical data onshore Greenland is logistically complicated by the presence of an up to 4 km thick ice sheet, permanently covering the largest part of the land mass. Hence previous seismic surveys have only been carried out offshore and near the coast of Greenland, where little information about the continental part of the crust could be gained. To get insight into crustal thickness and composition below the Greenland ice sheet, the TopoGreenland project collects the first ever seismic data onshore Greenland. Wide-angle data was acquired along an EW-trending profile, extending 350 km inland from the approximate edge of the stable ice cap near Scoresby Sund. Data is recorded by 350 Reftek Texan receivers for 10 equidistant shot points along the profile. We use forward ray tracing modelling to construct a two-dimensional velocity model from the observed travel times. These results show the first images of the subsurface velocity structure beneath the Greenland ice sheet and provide a link between the composition of the crust and the present-day topography of Greenland.

  17. Greenland Sea observations

    SciTech Connect

    Gudmandsen, P.; Mortensen, H.B.; Pedersen, L.T.; Skriver, H.; Minnett, P.

    1992-12-31

    ERS-1 SAR data have been acquired over the Greenland Sea and Fram Strait during two periods, the Ice Phase of three-day repeat cycle from January to March 1992 and a one-month period in the 35-day repeat cycle from 16 July to 15 August 1992. Most data became available by way of the Broadband Data Dissemination System, i.e. with a spatial resolution of about 100 m. With these data various algorithms have been tested to derive sea ice parameters such as ice extent, ice concentration and ice displacement. In the latter period data were collected to support the activities of a research vessel in the area mainly related to the large polynyas that form east and north of Greenland. The formation of polynyas could clearly be outlined but also other phenomena were observed related to the influence of wind streets and gravity waves associated with the atmospheric boundary layer. The data will have to be studied further including full-resolution data to substantiate the conclusions arrived at.

  18. mtDNA variation in Inuit populations of Greenland and Canada: migration history and population structure.

    PubMed

    Helgason, Agnar; Pálsson, Gísli; Pedersen, Henning Sloth; Angulalik, Emily; Gunnarsdóttir, Ellen Dröfn; Yngvadóttir, Bryndís; Stefánsson, Kári

    2006-05-01

    We examined 395 mtDNA control-region sequences from Greenlandic Inuit and Canadian Kitikmeot Inuit with the aim of shedding light on the migration history that underlies the present geographic patterns of genetic variation at this locus in the Arctic. In line with previous studies, we found that Inuit populations carry only sequences belonging to haplotype clusters A2 and D3. However, a comparison of Arctic populations from Siberia, Canada, and Greenland revealed considerable differences in the frequencies of these haplotypes. Moreover, large sample sizes and regional information about birthplaces of maternal grandmothers permitted the detection of notable differences in the distribution of haplotypes among subpopulations within Greenland. Our results cast doubt on the prevailing hypothesis that contemporary Inuit trace their all of their ancestry to so-called Thule groups that expanded from Alaska about 800-1,000 years ago. In particular, discrepancies in mutational divergence between the Inuit populations and their putative source mtDNA pool in Siberia/Alaska for the two predominant haplotype clusters, A2a and A2b, are more consistent with the possibility that expanding Thule groups encountered and interbred with existing Dorset populations in Canada and Greenland.

  19. Modelling Greenland Outlet Glaciers

    NASA Technical Reports Server (NTRS)

    vanderVeen, Cornelis; Abdalati, Waleed (Technical Monitor)

    2001-01-01

    The objective of this project was to develop simple yet realistic models of Greenland outlet glaciers to better understand ongoing changes and to identify possible causes for these changes. Several approaches can be taken to evaluate the interaction between climate forcing and ice dynamics, and the consequent ice-sheet response, which may involve changes in flow style. To evaluate the icesheet response to mass-balance forcing, Van der Veen (Journal of Geophysical Research, in press) makes the assumption that this response can be considered a perturbation on the reference state and may be evaluated separately from how this reference state evolves over time. Mass-balance forcing has an immediate effect on the ice sheet. Initially, the rate of thickness change as compared to the reference state equals the perturbation in snowfall or ablation. If the forcing persists, the ice sheet responds dynamically, adjusting the rate at which ice is evacuated from the interior to the margins, to achieve a new equilibrium. For large ice sheets, this dynamic adjustment may last for thousands of years, with the magnitude of change decreasing steadily over time as a new equilibrium is approached. This response can be described using kinematic wave theory. This theory, modified to pertain to Greenland drainage basins, was used to evaluate possible ice-sheet responses to perturbations in surface mass balance. The reference state is defined based on measurements along the central flowline of Petermann Glacier in north-west Greenland, and perturbations on this state considered. The advantage of this approach is that the particulars of the dynamical flow regime need not be explicitly known but are incorporated through the parameterization of the reference ice flux or longitudinal velocity profile. The results of the kinematic wave model indicate that significant rates of thickness change can occur immediately after the prescribed change in surface mass balance but adjustments in flow

  20. Horizontal transmission of nervous necrosis virus between turbot Scophthalmus maximus and Atlantic cod Gadus morhua using cohabitation challenge.

    PubMed

    Korsnes, Kjetil; Karlsbakk, Egil; Nylund, Are; Nerland, Audun Helge

    2012-05-15

    Experimental horizontal transmission of nervous necrosis virus (NNV) originating from halibut Hippoglossus hippoglossus was studied through cohabitation of intraperitoneally (i.p.) injected fish with uninfected fish for 125 d. The experimental groups consisted of i.p. injected turbot Scophthalmus maximus or i.p. injected Atlantic salmon Salmo salar with turbot, salmon or Atlantic cod Gadus morhua cohabitants. The initial weights were cod 10 g, salmon 40 g and turbot 3 g. NNV was detected in brain, eye and spleen by real-time reverse transcriptase PCR (qRT-PCR) in cod cohabitated with i.p. injected turbot after 90 and 125 d, suggesting NNV infection was transmitted horizontally from the turbot to cod. NNV was not detected in salmon that were cohabitated with i.p. challenged turbot or salmon. This study shows that NNV strains belonging to the Barfin Flounder Nervous Necrosis Virus (BFNNV) clade may be transmitted from halibut to cod via water. Hence there is a potential risk of horizontal transmission of the virus from farmed halibut to farmed and wild cod. The lack of detection of NNV in cohabitant salmon suggests that this fish species is less susceptible than cod, or not susceptible, to horizontal NNV transmission. This result might be influenced by the size of salmon, viral load in i.p. injected cohabitants or insufficient duration of the experiment.

  1. Greenland meltwater experiments

    NASA Astrophysics Data System (ADS)

    Olsen, S. M.; Schmith, T.

    2012-04-01

    We explore the climatic response to additional Greenland Ice Sheet melting in the EC-EARTH coupled climate model. As reference runs, we use an ensemble of two simulations from 1850 to present with historic forcing. For each of these we pick the years 1935,1950 and 1965, respectively as initial conditions for perturbed experiments with an additional freshwater forcing of 0.1 Sv distributed uniformly around Greenland , a plausible value in the upper end of future Greenland ice sheet melt estimates. We find give no evidence for abrupt transitions associated with tipping points in the Atlantic overturning circulation and mid-latitude heat transport. In fact, modelled decline in overturning in response to the additional forcing does not project onto a comparable reduction in the mid latitude (36N) ocean heat transport. This result points to an ongoing watermass transformation in the subpolar region and Arctic Mediterranean as a whole and a continued thermal mode of operation of the overturning. At the northern boundary of the subpolar region (60N) the response in overturning shows a contrasting increase in intensity along with an increase in heat transport. Whereas the latter may be expected as a result of freshwater capping and subsurface warming in the subpolar region, the increased overturning at 60N is more difficult to explain. In order to assess this in more detail we have quantified the individual thermohaline exchange components of light and dense water masses across the Greenland-Scotland Ridge. We find that the intensified overturning at 60N is reflected in increased transports of light Atlantic Water to the Nordic Seas. However, the vertical, thermohalinie overturning loop is not equally strengthened. On the contrary, we model a decline in the denser parts of the outflow, the overflows in the Denmark Strait and Faroe Bank Channel and a strong increase in the polar outflow in the Denmark Strait. We observe a gradual transition from a vertical mode of operation

  2. Alaska Resource Data File, Noatak Quadrangle, Alaska

    USGS Publications Warehouse

    Grybeck, Donald J.; Dumoulin, Julie A.

    2006-01-01

    This report gives descriptions of the mineral occurrences in the Noatak 1:250,000-scale quadrangle, Alaska. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  3. Greenland to gather more exploration data

    SciTech Connect

    Not Available

    1991-01-28

    Danish authorities are taking steps to make more exploration data available on Greenland in advance of a possible West Greenland shelf licensing round in 1993. Seismic data acquisition and other studies continue toward more fully evaluating Greenland's oil and gas potential. Geological Survey of Greenland (GGU), Copenhagen, Denmark, is processing 2,041 line miles of reflection seismic data shot on the West Greenland shelf in August and September of 1990. Sixty-fold stacks and migrations will be obtained. Total field magnetic data were also recorded during the survey, known as project Syd Vest Seis. Early work is under way to kick off the multicompany Kanumas seismic acquisition project, proposed in 1986, during 1991. Meanwhile, the Mineral Resources Administration for Greenland (MRA), Copenhagen, the Danish and Greenland governments aim to sweeten Greenland's exploration regulations prior to making areas available.

  4. Accumulation of polychlorinated biphenyls in turbot (Scophthalmus maximus) from seawater sediments and food

    NASA Astrophysics Data System (ADS)

    Courtney, W. A. M.; Langston, W. J.

    1980-03-01

    Juvenile turbot, Scophthalmus maximus (L.), were exposed to 0.58 µg 1-1 Aroclor 1254 in seawater, to sediments containing 100, 60 and 1 ppm or fed with cockle containing 20 ppm PCB (polychlorinated biphenyls). Concentration factors for liver and muscle were 104 and 103, respectively, for uptake of PCB from seawater. Contamination of muscle was similar to that of sediments containing 1 and 60 ppm PCB to which turbot were exposed, but less than the 20 ppm in their experimental diet. Contamination of flatfish in the North Sea area is compared with the levels of PCB in the flounder, Platichthys flesus (L.), in the River Thames and predictable values for uptake of PCB from different pathways discussed.

  5. Evaluation on activity of cytochrome p450 enzymes in turbot via a probe drug cocktail.

    PubMed

    Chang, Zhi-Qiang; Li, Jian; Zhai, Qian-Qian

    2014-12-01

    Cytochrome P450s (CYPs) are the main catalytic enzymes for metabolism by a variety of endogenous and exogenous substrates in mammals, fish, insects, etc. We evaluated the application of a multidrug cocktail on changes in CYP1, CYP2, and CYP3 activity in Turbot Scophthalmus maximus. The probe drugs were a combination of caffeine (5 mg/kg body weight), dapsone (5 mg/kg), and chlorzoxazone (10 mg/kg). After a single intraperitoneal injection of the cocktail, the concentration of all three probe drugs in the plasma increased quickly to a peak and then decreased gradually over 24 h. Pharmacokinetic profiles of the three probe drugs were determined using a noncompartmental analysis, and the typical parameters were calculated. In the assay for CYP induction, pretreatment with rifampicin significantly reduced the typical pharmacokinetic metrics for caffeine and chlorzoxazone, but not dapsone, indicating that the activity of CYP1 and CYP2 in turbot were induced by rifampicin. PMID:25369285

  6. Zinc, cadmium, mercury and selenium in polar bears (Ursus maritimus) from Central East Greenland

    SciTech Connect

    Dietz, R.; Born, E.W.; Agger, C.T.; Nielsen, C.O.

    1995-02-01

    Muscle, liver, and kidney tissues from 38 polar bears (Ursus maritimus) caught in the Scoresby Sound area, Central East Greenland, were analysed for zinc, cadmium, mercury and selenium. In general, cadmium concentrations were low in muscle, liver and kidney tissue. This finding can be explained by low cadmium levels in the blubber of ringed seals. The concentration of mercury in muscle tissue was low, whereas concentrations in liver and kidney tissue were relatively high. Mercury and cadmium were positively correlated with age in liver and kidney. Zinc was positively correlated with in kidney, and selenium was correlated with age in liver. Contrary to other marine mammals, polar bears had higher mercury levels in the kidneys than in the liver. In all three tissues polar bears had significantly lower cadmium levels than ringed seals from the same area. Mercury levels were significantly lower in the muscle tissue of polar bears than in ringed seals, where-as levels in the liver and kidney were significantly higher. The previous geographic trend for cadmium and mercury found in Canadian polar bears could be extended to cover East Greenland as well. Hence cadmium levels were higher in Greenland than in Canada, while the opposite was the case for mercury. Greenland polar bears had higher mercury and cadmium contents in livers and kidneys than polar bears from Svalbard. The mercury levels in muscle and liver tissue from polar bears from East Greenland were twice as high as found in bears from western Alaska, but half the levels found in northern Alaska. Cadmium and zinc were partially correlated in kidney tissue, and this was found for mercury and selenium as well. Cadmium and zinc showed molar ratios close to unity with the highest concentrations occurring in kidney tissue, while the levels of zinc exceeded cadmium in muscle and liver tissue by up to several decades. Mercury and selenium showed molar ratios close to unity in liver and kidneys. 56 refs., 5 figs., 6 tabs.

  7. Immunohistochemical detection and gene expression of TNFα in turbot (Scophthalmus maximus) enteromyxosis.

    PubMed

    Ronza, Paolo; Bermúdez, Roberto; Losada, Ana Paula; Sitjà-Bobadilla, Ariadna; Pardo, Belén G; Quiroga, María Isabel

    2015-11-01

    Enteromyxum scophthalmi (Myxozoa) constitutes one of the most devastating pathogens for turbot (Scophthalmus maximus, L.) aquaculture. This parasite causes a severe intestinal parasitosis that leads to a cachectic syndrome with high morbidity and mortality rates for which no therapeutic options are available. Presence of inflammatory infiltrates, increased apoptotic rates and epithelial detaching have been described at intestinal level, as well as leukocyte depletion in lymphohaematopoietic organs. Previous investigations on enteromyxosis in turbot showed the high susceptibility of this species to the parasite and reported the existence of a dysregulated immune response against the parasite. The pleiotropic cytokine tumour necrosis factor alpha (TNFα) plays a major role in immune response and is involved in a wide range of biological activities. In teleost, the gene expression of this cytokine has been found regulated under several pathological conditions. Teleost TNFα shows some analogous functions with its mammalian counterparts, but the extent of its activities is still poorly understood. Cytokines are generally considered as a double-edge sword and TNFα has been implicated in the pathogenesis of different inflammatory diseases as well as in wasting syndromes described in mammals. The aim of this work was to analyse the expression of TNFα during enteromyxosis with molecular (Q-PCR) and morphological (immunohistochemistry) tools. Kidney, spleen and pyloric caeca from turbot with moderate and severe infections were analysed and compared to healthy naïve fish. TNFα expression was increased in both spleen and kidney in the earlier stages of the disease, whereas in severely infected fish, the expression decreased, especially in kidney. At the intestinal level, an increase in the number of TNFα-positive cells was noticed, which was proportional to the infiltration of inflammatory cells. The results demonstrate the involvement of TNFα in the immune response to

  8. Diet and niche overlap of southern populations of brill Scophthalmus rhombus and turbot Scophthalmus maximus.

    PubMed

    Vinagre, C; Silva, A; Lara, M; Cabral, H N

    2011-11-01

    The diets of adult brill Scophthalmus rhombus and turbot Scophthalmus maximus from the Portuguese coast relied mostly on fishes. There was a higher diversity of food items compared to their northern counterparts, and several of the identified prey are the first records of these species, including a brown alga, echinoderms, nematodes, oligochaetes, gastropods, bivalves and various fish species. The diet of the two species was significantly different and niche overlap was low. PMID:22026615

  9. Northern Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Seasonal ice in the Beaufort Sea off Alaska's North Slope has begun its spring retreat. This true color MODIS image from March 18, 2002, shows the pack ice in the Chuckchi Sea (left) and Beaufort Sea (top) backing away from its winter position snug up against Alaska's coasts, beginning its retreat into the Arctic Ocean. While not as pronounced in the Beaufort and Chukchi Seas as other part of the Arctic, scientists studying Arctic sea ice over the course of the century have documented dramatic changes in the extent of Arctic sea ice. It retreats farther in the summer and does not advance as far in the winter than it did a half-century ago. Both global warming and natural variation in regional weather systems have been proposed as causes. Along the coastal plain of the North Slope, gray-brown tracks (see high-resolution image) hint at melting rivers. South of the North Slope, the rugged mountains of the Brooks Range make a coast-to-coast arc across the state. Coming in at the lower right of the image, the Yukon River traces a frozen white path westward across half the image before veering south and out of view. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  10. Identification of the Major Sex-Determining Region of Turbot (Scophthalmus maximus)

    PubMed Central

    Martínez, Paulino; Bouza, Carmen; Hermida, Miguel; Fernández, Jesús; Toro, Miguel Angel; Vera, Manuel; Pardo, Belén; Millán, Adrián; Fernández, Carlos; Vilas, Román; Viñas, Ana; Sánchez, Laura; Felip, Alicia; Piferrer, Francesc; Ferreiro, Isabel; Cabaleiro, Santiago

    2009-01-01

    Sex determination in fish is a labile character in evolutionary terms. The sex-determining (SD) master gene can differ even between closely related fish species. This group is an interesting model for studying the evolution of the SD region and the gonadal differentiation pathway. The turbot (Scophthalmus maximus) is a flatfish of great commercial value, where a strong sexual dimorphism exists for growth rate. Following a QTL and marker association approach in five families and a natural population, we identified the main SD region of turbot at the proximal end of linkage group (LG) 5, close to the SmaUSC-E30 marker. The refined map of this region suggested that this marker would be 2.6 cM and 1.4 Mb from the putative SD gene. This region appeared mostly undifferentiated between males and females, and no relevant recombination frequency differences were detected between sexes. Comparative genomics of LG5 marker sequences against five model species showed no similarity of this chromosome to the sex chromosomes of medaka, stickleback, and fugu, but suggested a similarity to a sex-associated QTL from Oreochromis spp. The segregation analysis of the closest markers to the SD region demonstrated a ZW/ZZ model of sex determination in turbot. A small proportion of families did not fit perfectly with this model, which suggests that other minor genetic and/or environmental factors are involved in sex determination in this species. PMID:19786621

  11. Identification of the major sex-determining region of turbot (Scophthalmus maximus).

    PubMed

    Martínez, Paulino; Bouza, Carmen; Hermida, Miguel; Fernández, Jesús; Toro, Miguel Angel; Vera, Manuel; Pardo, Belén; Millán, Adrián; Fernández, Carlos; Vilas, Román; Viñas, Ana; Sánchez, Laura; Felip, Alicia; Piferrer, Francesc; Ferreiro, Isabel; Cabaleiro, Santiago

    2009-12-01

    Sex determination in fish is a labile character in evolutionary terms. The sex-determining (SD) master gene can differ even between closely related fish species. This group is an interesting model for studying the evolution of the SD region and the gonadal differentiation pathway. The turbot (Scophthalmus maximus) is a flatfish of great commercial value, where a strong sexual dimorphism exists for growth rate. Following a QTL and marker association approach in five families and a natural population, we identified the main SD region of turbot at the proximal end of linkage group (LG) 5, close to the SmaUSC-E30 marker. The refined map of this region suggested that this marker would be 2.6 cM and 1.4 Mb from the putative SD gene. This region appeared mostly undifferentiated between males and females, and no relevant recombination frequency differences were detected between sexes. Comparative genomics of LG5 marker sequences against five model species showed no similarity of this chromosome to the sex chromosomes of medaka, stickleback, and fugu, but suggested a similarity to a sex-associated QTL from Oreochromis spp. The segregation analysis of the closest markers to the SD region demonstrated a ZW/ZZ model of sex determination in turbot. A small proportion of families did not fit perfectly with this model, which suggests that other minor genetic and/or environmental factors are involved in sex determination in this species. PMID:19786621

  12. Molecular identification, polymorphism, and expression analysis of major histocompatibility complex class IIA and B genes of turbot (Scophthalmus maximus).

    PubMed

    Zhang, Yu-Xi; Chen, Song-Lin

    2006-01-01

    Major histocompatibility complex (MHC) class II has a central role in the adaptive immune system by presenting foreign peptides to the T-cell receptor. The full lengths of MHC class II A and B cDNA were cloned from turbot by homology cloning and rapid amplification of cDNA ends polymerase chain reaction (RACE PCR), and genomic organization, molecular polymorphism, and expression of turbot class IIB gene were examined to study the function of class IIB gene in fish. The deduced amino acid sequence of turbot class II A (GenBank accession no.DQ001730) and turbot class IIB (GenBank accession no. DQ094170) had 69.8%, 67.6%, 65.5%, 59.2%, 54.5%, 52.8%, 46.2%, 46.6%, 28.3%, 28.5%, 22.2% identity and 71.5%, 70.7%, 67.1%, 68.4%, 46.7%, 53.5%, 46.7%, 50.0%, 25.2%, 29.2%, 27.6% identity with those of Japanese flounder, striped sea bass, red sea bream, cichlid, rainbow trout, Atlantic salmon, carp, zebrafish, nurse shark, mouse and human, respectively. Eleven class IIB alleles were identified from three turbot individuals. The amino acid sequence of turbot class IIB designated as Scma-DAB*0101 had 86.9%, 88.6%, 88.6%, 89.4%, 87.8%, 86.9%, 84.1%, 86.5%, 87.3%, 77.1%, and 86.9% identity with those of turbot class IIB 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 (Scma-DAB*0201- Scma-DAB*1201), respectively. Six different class IIB alleles observed in a single individual may infer the existence of three loci at least. Semiquantitative reverse transcriptase PCR (RT-PCR) demonstrated that turbot class IIA and B were ubiquitously expressed in normal tissues. Challenge of turbot with pathogenic bacteria, Vibrio anguillarum, resulted in a significant decrease in the expression of MHC class IIB mRNA from 24 h to 48 h after infection in liver and head kidney, and a significant decrease from 24 h to 72 h after infection in spleen, followed by an increase after 96 h, respectively.

  13. Effects of waterborne Fe(II) on juvenile turbot Scophthalmus maximus: analysis of respiratory rate, hematology and gill histology

    NASA Astrophysics Data System (ADS)

    Wu, Zhihao; You, Feng; Liu, Hongjun; Liu, Mengxia; Li, Jun; Zhang, Peijun

    2012-03-01

    The concentration of Fe(II) is high in some groundwater supplies used in turbot culture, and the toxicity of waterborne Fe(II) is unknown. We investigated the stress responses of juvenile turbot, Scophthalmus maximus, exposed to Fe(II) of different concentrations (0.01, 0.05, 0.1, 0.5, 1, and 2 mg/L) for 1, 7, 14, and 28 d, under the same ambient conditions of other parameters. Changes in respiratory rate, hematological parameters, and gill structure were determined. The results show that waterborne Fe(II) did not cause severe hematological perturbation to turbot. A low-medium Fe(II) concentration (lower than 0.1 mg/L) could boost the respiratory rate, and caused no or very limited damage to fish. A high Fe(II) concentration (0.1 mg/L or higher), however, caused gill damage, such as vacuoles in branchial lamellae, epithelial necrosis, and hypertrophy of epithelial cells, and even death after extended exposure time. Therefore, excess waterborne Fe(II) and long-term exposure to Fe(II) could be responsible for poor growth and high mortality of turbot in culture. The concentration of waterborne Fe(II) in turbot culture should be kept below 0.1 mg/L.

  14. The Greenland Telescope

    NASA Astrophysics Data System (ADS)

    Grimes, Paul; Blundell, Raymond

    2012-09-01

    In the spring of 2010, the Academia Sinica Institute of Astronomy and Astrophysics, and the Smithsonian Astrophysical Observatory, acquired the ALMA North America prototype antenna - a state-of-the-art 12-m diameter dish designed for submillimeter astronomy. Together with the MIT-Haystack Observatory and the National Radio Astronomy Observatory, the plan is to retrofit this antenna for cold-weather operation and equip it with a suite of instruments designed for a variety of scientific experiments and observations. The primary scientific goal is to image the shadow of the Super-Massive Black Hole in M87 in order to test Einstein’s theory of relativity under extreme gravity. This requires the highest angular resolution, which can only be achieved by linking this antenna with others already in place to form a telescope almost the size of the Earth. We are therefore developing plans to install this antenna at the peak of the Greenland ice-sheet. This location will produce an equivalent North-South separation of almost 9,000 km when linked to the ALMA telescope in Northern Chile, and an East-West separation of about 6,000 km when linked to SAO and ASIAA’s Submillimeter Array on Mauna Kea, Hawaii, and will provide an angular resolution almost 1000 times higher than that of the most powerful optical telescopes. Given the quality of the atmosphere at the proposed telescope location, we also plan to make observations in the atmospheric windows at 1.3 and 1.5 THz. We will present plans to retrofit the telescope for cold-weather operation, and discuss potential instrumentation and projected time-line.

  15. Brief communication: Getting Greenland's glaciers right - a new data set of all official Greenlandic glacier names

    NASA Astrophysics Data System (ADS)

    Bjørk, A. A.; Kruse, L. M.; Michaelsen, P. B.

    2015-12-01

    Place names in Greenland can be difficult to get right, as they are a mix of Greenlandic, Danish, and other foreign languages. In addition, orthographies have changed over time. With this new data set, we give the researcher working with Greenlandic glaciers the proper tool to find the correct name for glaciers and ice caps in Greenland and to locate glaciers described in the historic literature with the old Greenlandic orthography. The data set contains information on the names of 733 glaciers, 285 originating from the Greenland Ice Sheet (GrIS) and 448 from local glaciers and ice caps (LGICs).

  16. Self-Sufficiency in Northern Justice Issues. Proceedings of the Northern Justice Society Meeting (5th, Sitka, Alaska, April 1991).

    ERIC Educational Resources Information Center

    Griffiths, Curt Taylor, Ed.

    As indigenous peoples in the Arctic move closer to sovereignty, self-sufficiency in the realm of criminal justice assumes paramount importance. This book outlines initiatives and strategies to improve the delivery of justice services to aboriginal peoples in Canada, Alaska, and Greenland. Topics include: social and spiritual causes of alcoholism…

  17. The Pedagogical Situation in Greenland.

    ERIC Educational Resources Information Center

    Gunther, Bent

    The history of Greenland's educational activities began in 1721 with the work of a missionary who encouraged the people to learn to read and write. A century later, higher education became available. In 1905, legislation was enacted that served as a milestone of progress for the growth of education. Separation from Denmark, which was leading…

  18. Greenland: More Questions than Answers.

    ERIC Educational Resources Information Center

    Allison, Pete

    1998-01-01

    Journal entries, reflections, and interviews from a phenomenological study indicate the benefits experienced by 70 British youth participating in a six-week Greenland expedition. Themes emerging from the data include reflection on values, life and career plans, friendships and relationships, connectedness to self and society, environmental…

  19. Outbreak of trichinellosis associated with consumption of game meat in West Greenland.

    PubMed

    Møller, Lone Nukâraq; Petersen, Eskild; Kapel, Christian M O; Melbye, Mads; Koch, Anders

    2005-09-01

    The Inuit population of the Arctic has always been at risk of acquiring trichinellosis and severe outbreaks have been recorded in Alaska and Canada. In West Greenland, a number of large outbreaks took place during the 1940s and 1950s; they involved total 420 cases including 37 deaths. Since then only sporadic cases have been reported. Here, we describe an outbreak of infection with Trichinella spp. after consumption of infected meat presumably from walrus or polar bear caught in western Greenland. Six persons who had eaten of the walrus and polar bear meat were two males and four females, age range 6--47 years. Using ELISA and Western blot analysis (Trichinella-specific IgG antibodies against excreted/secreted antigen and synthetic tyvelose antigen, respectively) four of these persons were found to be sero-positive for Trichinella antibodies, with three of these having clinical symptoms compatible with trichinellosis. On re-test, 12--14 months later one of the two sero-negative persons had sero-converted, probably due to a new, unrelated infection. This study demonstrates that acquiring Trichinella from the consumption of marine mammals remains a possibility in Greenland, and that cases may go undetected. Trichinellosis in Greenland can be prevented by the implementation of public health measures.

  20. Alaska's Children, 1997.

    ERIC Educational Resources Information Center

    Douglas, Dorothy, Ed.

    1997-01-01

    These four issues of the "Alaska's Children" provide information on the activities of the Alaska Head Start State Collaboration Project and other Head Start activities. Legal and policy changes affecting the education of young children in Alaska are also discussed. The Spring 1997 issue includes articles on brain development and the "I Am Your…

  1. Alaska's Economy: What's Ahead?

    ERIC Educational Resources Information Center

    Alaska Review of Social and Economic Conditions, 1987

    1987-01-01

    This review describes Alaska's economic boom of the early 1980s, the current recession, and economic projections for the 1990s. Alaska's economy is largely influenced by oil prices, since petroleum revenues make up 80% of the state government's unrestricted general fund revenues. Expansive state spending was responsible for most of Alaska's…

  2. Alaska Natives & the Land.

    ERIC Educational Resources Information Center

    Arnold, Robert D.; And Others

    Pursuant to the Native land claims within Alaska, this compilation of background data and interpretive materials relevant to a fair resolution of the Alaska Native problem seeks to record data and information on the Native peoples; the land and resources of Alaska and their uses by the people in the past and present; land ownership; and future…

  3. Alaska Women: A Databook.

    ERIC Educational Resources Information Center

    White, Karen; Baker, Barbara

    This data book uses survey and census information to record social and economic changes of the past three decades and their effects upon the role of Alaska women in society. Results show Alaska women comprise 47% of the state population, an increase of 9% since 1950. Marriage continues as the predominant living arrangement for Alaska women,…

  4. Annual and spatial variation in the abundance length and condition of juvenile turbot ( Psetta maxima L.) on nursery grounds on the west coast of Ireland: 2000-2007

    NASA Astrophysics Data System (ADS)

    Haynes, Paula S.; Brophy, Deirdre; McGrath, David; O'Callaghan, Roisin; Comerford, Stephen; Casburn, Paul

    2010-11-01

    Turbot ( Psetta maxima Linnaeus) is a high value commercially exploited marine flatfish which occurs in European waters, from the Northeast Atlantic to the Arctic Circle, the Baltic and Mediterranean Sea. In Ireland, turbot are the most valuable commercial non-quota species. Very little is known about their population dynamics in the wild, in particular during the sandy beach nursery phase of the life history. In 2000, a survey was established to assess flatfish species on nursery grounds on the west coast of Ireland. Eleven sandy beaches were assessed for 0+ turbot by beach seining, over an eight year period (2000-2007) during the months of August and September. The objective of the study was to estimate juvenile turbot abundance and size structure to determine if any spatial and annual trends existed. Large scale variability in the recruitment of fish to nursery grounds may be indicative of fluctuations in the adult stock. Turbot were found to recruit to five beaches consistently over the eight year period. Temporal and spatial variability in the relative abundance and length of turbot was discerned, with no apparent overall trend. However, certain nursery grounds were shown in most of the years examined to support higher abundances of turbot in comparison to other areas over the eight year period. Turbot abundances on nursery grounds were significantly correlated with mean spring sea temperatures during the pelagic stage. The condition of turbot did not significantly differ on an annual or spatial scale. Mean densities of 0+ turbot along the Irish coast were found to be similar and at times higher than other areas in Europe, ranging from 0.1 (± 0.3) individuals 1000 m - 2 to 18.5 (± 6.9) individuals 1000 m - 2 . Mean turbot total length on beaches ranged from 3.8 cm (± 0.6) to 6.6 cm (± 4.3). The observed spatial and temporal variability in abundance and length highlights the need for long-term studies when assessing juvenile flatfish populations. Results

  5. Trophic transfer and effects of DDT in male hornyhead turbot (Pleuronichthys verticalis) from Palos Verdes Superfund site, CA (USA) and comparisons to field monitoring.

    PubMed

    Crago, Jordan; Xu, Elvis Genbo; Kupsco, Allison; Jia, Fang; Mehinto, Alvine C; Lao, Wenjian; Maruya, Keith A; Gan, Jay; Schlenk, Daniel

    2016-06-01

    High concentrations of DDT and metabolites (ΣDDT) have been detected in sediment and the demersal flatfish hornyhead turbot (Pleuronichtys verticalis) collected from Palos Verdes (PV), California, USA, a site contaminated with over 100 metric tons of DDT throughout 1960s-70s. This study was conducted to assess the transfer of ΣDDT from PV-sediment into polychaetes (Neanthes arenaceodentata) and hornyhead turbot, and to investigate if the responses in turbots from two different laboratory exposures mimic those in turbots caught in PV (PV-turbot). Turbot fed PV-sediment-contaminated polychaete for 7 days had liver concentrations of ΣDDT similar to PV-turbot. After 28 days, ΣDDT also accumulated in livers of turbot gavaged with a ΣDDT mixture. In vitro cell bioassays indicated significant increases of 17β-estradiol equivalents (EEQ) in turbot bile extracts as compared to the control in the 7-day study. These responses corresponded to those measured in PV-fish. Glucocorticoid receptor (GR), anti-androgen receptor (anti-AR), estrogen receptor (ER) or aryl hydrocarbon receptor (AhR) activities were also observed in extracts of PV-sediment, and PV-sediment-exposed worm. Anti-AR, AhR and GR activities were significantly higher in PV-sediment than reference sediment (San Diego, SD). Higher transcripts of hepatic VTG, ERα and ERβ were found in PV-turbot than SD-turbot, but were unaltered in fish exposed to sediment-contaminated worms for the 7-day study. In contrast, liver extracts from the 28-day treatment of ΣDDT showed lower EEQ but similar hepatic VTG and ERβ transcripts relative to those of PV-turbot. These data indicated that trophic transfer of sediment-associated DDT in 7-day exposures corresponded to field measurements of DDT residues and in vitro ER bioactivities, but failed to mimic in vivo biological effects observed in field fish. In contrast, treatment with ΣDDT alone for 28 days mimicked in vivo biological effects of DDTs in PV fish, but did not

  6. Effects of temperature and salinity on embryonic development of turbot ( Scophthalmus maximus L.) from the North Sea, and comparisons with Baltic populations

    NASA Astrophysics Data System (ADS)

    Karås, P.; Klingsheim, V.

    1997-08-01

    Optimum temperature and salinity conditions for viable hatch were studied for turbot ( Scophthalmus maximus L.) from the North Sea. Temperatures ranging from 6 to 22°C and salinities from 5 to 35‰ were used. Optimum conditions were observed to be between 12 and 18°C at salinities between 20 and 35‰. This contrasted with corresponding data for turbot from the southern Baltic proper, according to which survival sharply decreased in temperatures below 14°C and was high in salinities of 10 to 15‰. Thus, it is concluded that Baltic and Atlantic turbot should be considered as different races.

  7. Variation in the immunoglobulin levels in turbot ( Scophthalmus maximus) after vaccination with Streptococcus iniae

    NASA Astrophysics Data System (ADS)

    Zhan, Wenbin; Liu, Hongming; Xing, Jing; Sheng, Xiuzhen; Tang, Xiaoqian

    2009-09-01

    A pathogenic bacterium (S636), identified as Streptococcus iniae, was isolated from turbot ( Scophthalmus maximus) in 2005. We immunized turbot with formalin-killed S. iniae four times (on days 1, 14, 21, and 28) by intraperitoneal inoculation. After each vaccination, we obtained serum samples and isolated the lymphocytes from the peripheral blood, spleen, pronephros, and mesonephros. We measured surface Ig-positive (sIg+) lymphocytes and serum antibody levels from these organs using flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively, using monoclonal antibodies against turbot immunoglobulin. We confirmed that the antibody reacted with both the surface and plasma Ig by confocal laser scanning microscopy and electron microscopy. The percentage of sIg+ in the lymphocytes increased following each successive vaccination. The mean percentage increased from 31.96% (control) to 37.49%, 38.36%, 42.9%, and 51.63% in the peripheral blood; from 27.09% to 36.63%, 36.81%, 39.28%, and 46.0% in the spleen; from 22.2% to 28.99%, 29.21%, 32.83%, and 41.58% in pronephros; and from 18.12% to 22.17%, 22.45%, 25.69%, and 31.68% in the mesonephros. The ELISA results were consistent with these results. Both the total and specific antibody levels increased with each vaccination. The mean OD value of the specific antibody assay increased from 0.094, to 0.269, 0.283, 0.333, and 0.421; for total antibody the mean OD value increased from 0.133, to 0.292, 0.323, 0.413, and 0.527.

  8. Stress and immune responses in skin of turbot (Scophthalmus maximus) under different stocking densities.

    PubMed

    Jia, Rui; Liu, Bao-Liang; Feng, Wen-Rong; Han, Cen; Huang, Bin; Lei, Ji-Lin

    2016-08-01

    Fish skin and its mucus provide the first line of defense against chemical, physical and biological stressors, but little is known about the role of skin and its mucus in immune response to crowding stress. In the present study, we investigated the stress and immune responses in skin of turbot (Scophthalmus maximus) under different stocking densities. Turbot (average weight 185.4 g) were reared for 120 days under three densities: low density (LD), medium density (MD), and high density (HD). After 120 days, fish were weighed and sampled to obtain blood, mucus and skin tissues which were used for analyses of biochemical parameters and genes expression. The results showed HD treatment significantly suppressed growth and enhanced plasma cortisol and glucose levels (P < 0.05). In mucus, the activities of lysozyme (LZM), alkaline phosphatase (ALP) and esterase in HD treatment were lower than LD and MD treatments (P < 0.05) In skin, HD treatment resulted in up-regulation in malondialdehyde (MDA) formation and heat shock protein 70 (HSP 70) mRNA level, and down-regulation in activity of superoxide dismutase (SOD) and the transcriptions of glutathione-s-transferase (GST), interleukin-1β (IL-1β), tumor necrosis factor -α (TNF-α), insulin-like growth factor- (IGF-) and LZM (P < 0.05). Overall, the data suggested that overly high stocking density was a stressor which caused an immunosuppression in skin of turbot. Moreover, this information would help to understand the skin immunity and their relation with stress and disease in fish. PMID:27235366

  9. Comprehensive transcriptomic analysis of the process of gonadal sex differentiation in the turbot (Scophthalmus maximus).

    PubMed

    Ribas, L; Robledo, D; Gómez-Tato, A; Viñas, A; Martínez, P; Piferrer, F

    2016-02-15

    The turbot is a flatfish with a ZW/ZZ sex determination system but with a still unknown sex determining gene(s), and with a marked sexual growth dimorphism in favor of females. To better understand sexual development in turbot we sampled young turbot encompassing the whole process of gonadal differentiation and conducted a comprehensive transcriptomic study on its sex differentiation using a validated custom oligomicroarray. Also, the expression profiles of 18 canonical reproduction-related genes were studied along gonad development. The expression levels of gonadal aromatase cyp19a1a alone at three months of age allowed the accurate and early identification of sex before the first signs of histological differentiation. A total of 56 differentially expressed genes (DEG) that had not previously been related to sex differentiation in fish were identified within the first three months of age, of which 44 were associated with ovarian differentiation (e.g., cd98, gpd1 and cry2), and 12 with testicular differentiation (e.g., ace, capn8 and nxph1). To identify putative sex determining genes, ∼4.000 DEG in juvenile gonads were mapped and their positions compared with that of previously identified sex- and growth-related quantitative trait loci (QTL). Although no genes mapped to the previously identified sex-related QTLs, two genes (foxl2 and 17βhsd) of the canonical reproduction-related genes mapped to growth-QTLs in linkage group (LG) 15 and LG6, respectively, suggesting that these genes are related to the growth dimorphism in this species. PMID:26586209

  10. Molecular cloning and expression analysis of interferon stimulated gene 15 (ISG15) in turbot, Scophthalmus maximus.

    PubMed

    Lin, Jing-Yun; Hu, Guo-Bin; Liu, Da-Hai; Li, Song; Liu, Qiu-Ming; Zhang, Shi-Cui

    2015-08-01

    The interferon stimulated gene 15 (ISG15) is strongly induced in many cell types by double-stranded RNA (polyinosinic: polycytidylic acid, poly I:C) and viral infection. In this study, we described the nucleotide, mRNA tissue distribution and regulation of an ISG15 gene from turbot, Scophthalmus maximus (SmISG15). SmISG15 gene is 862 bp in length, composed of two exons and one intron, and encodes 158 amino acids. The deduced protein exhibits the highest homology (44.7-71.2% identity) with ISG15s from other fishes and possesses two conserved tandem ubiquitin-like (UBL) domains and a C-terminal RLRGG conjugating motif known to be important for the functions of ISG15s in vertebrates. Phylogenetic analysis grouped SmISG15 into fish ISG15. SmISG15 mRNA was constitutively expressed in all tissues examined, with higher levels observed in immune organs. Gene expression analysis was performed for SmISG15 in the spleen, head kidney, gills and muscle of turbots challenged with poly I:C or turbot reddish body iridovirus (TRBIV) over a 7-day time course. The result showed that SmISG15 was upregulated by both stimuli in all four tissues, with induction by poly I:C apparently stronger and initiated more quickly. A two-wave induced expression of SmISG15 was seen in the spleen, head kidney and gills, suggesting an induction of SmISG15 either by IFN-dependent or -independent pathway. These results provide insights into the roles of fish ISG15 in antiviral immunity. PMID:26095010

  11. Effect of stocking density on performances of juvenile turbot ( Scophthalmus maximus) in recirculating aquaculture systems

    NASA Astrophysics Data System (ADS)

    Li, Xian; Liu, Ying; Blancheton, Jean-Paul

    2013-05-01

    Limited information has been available about the influence of loading density on the performances of Scophthalmus maximus, especially in recirculating aquaculture systems (RAS). In this study, turbot (13.84±2.74 g; average weight±SD) were reared at four different initial densities (low 0.66, medium 1.26, sub-high 2.56, high 4.00 kg/m2) for 10 weeks in RAS at 23±1°C. Final densities were 4.67, 7.25, 14.16, and 17.47 kg/m2, respectively, which translate to 82, 108, 214, and 282 percent coverage of the tank bottom. Density had both negative and independent impacts on growth. The final mean weight, specific growth rate (SGR), and voluntary feed intake significantly decreased and the coefficient of variation (CV) of final body weight increased with increase in stocking density. The medium and sub-high density groups did not differ significantly in SGR, mean weight, CV, food conversion rate (FCR), feed intake, blood parameters, and digestive enzymes. The protease activities of the digestive tract at pH 7, 8.5, 9, and 10 were significantly higher for the highest density group, but tended to be lower (not significantly) at pH 4 and 8.5 for the lowest density group. The intensity of protease activity was inversely related to feed intake at the different densities. Catalase activity was higher (but not significantly) at the highest density, perhaps because high density started to induce an oxidative effect in turbot. In conclusion, turbot can be cultured in RAS at a density of less than 17.47 kg/m2. With good water quality and no feed limitation, initial density between 1.26 and 2.56 kg/m2 (final: 7.25 and 14.16 kg/m2) would not negatively affect the turbot cultured in RAS. For culture at higher density, multi-level feeding devices are suggested to ease feeding competition.

  12. Effect of temperature and short chain fructooligosaccharides supplementation on the hepatic oxidative status and immune response of turbot (Scophthalmus maximus).

    PubMed

    Guerreiro, Inês; Pérez-Jiménez, Amalia; Costas, Benjamín; Oliva-Teles, Aires

    2014-10-01

    In this study the effect of diet supplementation with different levels of short-chain fructooligosaccharides (scFOS) on the hepatic oxidative status, hematology and innate immune parameters was evaluated in turbot reared at 15 °C and 20 °C. Four practical diets containing half of the protein provided by plant ingredients and the other half by fish meal were supplemented with scFOS at 0%, 0.5%, 1.0% and 2.0% and fed to turbot juveniles for 9 weeks. Independently of the rearing temperature, diet with 1% scFOS increased the haematocrit (Ht) while 2% scFOS augmented the mean corpuscular haemoglobin concentration (MCHC). Mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), white blood cells (%) and lysozyme were higher in fish reared at 15 °C, whereas red blood cells and neutrophil numbers increased in fish reared at 20 °C. Catalase (CAT) and glutathione peroxidase (GPX) activities were affected by rearing temperature being lower in fish reared at 20 °C. Compared to the control diet, at 15 °C, turbot fed 0.5 or 1% scFOS presented lower activities of CAT and glutathione reductase (GR). At 20 °C turbot fed the 2% scFOS diet presented lower activities of CAT and GPX. Lipid peroxidation (LPO) and glucose 6-phosphate dehydrogenase (G6PDH) activity were not affected by temperature nor dietary prebiotic incorporation. Results of this study suggest scFOS has no effect on innate immunology or hematology. High temperature (20 °C) does not induce turbot oxidative stress, but the recommended dietary scFOS incorporation level for counteracting oxidative stress may differ with other rearing temperature. PMID:25149593

  13. Evaluation of reproductive endocrine status in hornyhead turbot sampled from Southern California's urbanized coastal environments.

    PubMed

    Reyes, Jesus A; Vidal-Dorsch, Doris E; Schlenk, Daniel; Bay, Steven M; Armstrong, Jeffrey L; Gully, Joseph R; Cash, Curtis; Baker, Michael; Stebbins, Timothy D; Hardiman, Gary; Kelley, Kevin M

    2012-12-01

    As part of a regionwide collaboration to determine the occurrence of contaminants and biological effects in coastal ecosystems offshore of urban southern California, the present study characterized the reproductive endocrinology of an indigenous flatfish, the hornyhead turbot (Pleuronichthys verticalis), and compared groups sampled from different study sites representing varying degrees of pollution to screen for potential endocrine disruptive effects. Turbot were sampled from locations near the coastal discharge sites of four large municipal wastewater treatment plants (WWTPs) located between Los Angeles and San Diego, California, USA, and were compared with fish sampled from three far-field reference locations in the region. Despite environmental presence of both legacy contaminants and contaminants of emerging concern and evidence for fish exposure to several classes of contaminants, both males and females generally exhibited coordinated seasonal reproductive cycles at all study sites. Patterns observed included peaks in sex steroids (17β-estradiol, testosterone, 11-ketotestosterone) in the spring and low levels in the fall, changes corresponding to similarly timed gonadal changes and plasma vitellogenin concentrations in females. Comparisons between fish captured at the different study sites demonstrated some regional differences in plasma levels of estrogens and androgens, indicative of location-associated effects on the endocrine system. The observed differences, however, could not be linked to the ocean discharge locations of four of the largest WWTPs in the world.

  14. Chronic rapamycin treatment on the nutrient utilization and metabolism of juvenile turbot (Psetta maxima)

    PubMed Central

    Wang, Qingchao; He, Gen; Mai, Kangsen; Xu, Wei; Zhou, Huihui; Wang, Xuan; Mei, Lin

    2016-01-01

    High dietary protein inclusion is necessary in fish feeds and also represents a major cost in the aquaculture industry, which demands improved dietary conversion into body proteins in fish. In mammals, the target of rapamycin (TOR) is a key nutritionally responsive molecule governing postprandial anabolism. However, its physiological significance in teleosts has not been fully examined. In the present study, we examined the nutritional physiology of turbot after chronic rapamycin inhibition. Our results showed that a 6-week inhibition of TOR using dietary rapamycin inclusion (30 mg/kg diet) reduced growth performance and feed utilization. The rapamycin treatment inhibited TOR signaling and reduced expression of key enzymes in glycolysis, lipogenesis, cholesterol biosynthesis, while increasing the expression of enzymes involved in gluconeogenesis. Furthermore, rapamycin treatment increased intestinal goblet cell number in turbot, while the expressions of Notch and Hes1 were down regulated. It was possible that stimulated goblet cell differentiation by rapamycin was mediated through Notch-Hes1 pathway. Therefore, our results demonstrate the important role of TOR signaling in fish nutritional physiology. PMID:27305975

  15. Identification and characterization of pathogen to bacterial septicaemia in cultured turbot, Scophthalmus maximus

    NASA Astrophysics Data System (ADS)

    Qin, Guomin; Zhang, Xiaojun; Chen, Cuizhen; Fang, Hai; Zhan, Wenbin

    2007-10-01

    Bacteria-infected turbots Scophthalmus maximus with septicaemia were examined between 2001 and 2004 in aspects of the conditions of disease occurrence, clinical syndromes and pathological changes. The phenotypic information of pathogenic bacteria was studied, including morphology, physiological and biochemical characteristics, and the mol% G+C of the DNA. In addition, representative strains (S010623-1, LH031120-1) were selected for molecular identification by partial 16S rRNA gene sequencing. The results show that the isolates (LH031120-1 to LH031120-6, HT040308-1 to HT040308-6, HT040620-1 to HT040620-6) from three farms were identified as Edwardsiella tarda. The isolates (S010610-1 to S010610-10, S010623-1 to S010623-20) from one farm were identified as Listonella anguillarum. We conducted studies on the pathogenicity of isolates by artificial infection, and revealed all infected groups in morbidity and mortality. The septicaemia infected turbot showed a syndrome similar to that of the naturally infected fish. Antibiotic sensitivity showed that of 37 antimicrobial agents, E. tarda was sensitive to 27 agents, and L. anguillarum was sensitive to 21 agents.

  16. The mucosal expression signatures of g-type lysozyme in turbot (Scophthalmus maximus) following bacterial challenge.

    PubMed

    Gao, Chengbin; Fu, Qiang; Zhou, Shun; Song, Lin; Ren, Yichao; Dong, Xiaoyu; Su, Baofeng; Li, Chao

    2016-07-01

    The mucosal surfaces constitute the first line of host defense against infection, and also serve as the dynamic interfaces that simultaneously mediate a diverse array of critical physiological processes, while in constantly contact with a wide range of pathogens. The lysozymes are considered as key components for innate immune response to pathogen infection with their strong antibacterial activities. But their activities in mucosal immune responses were always overlooked, especially for g-type lysozymes, whose expression patterns in mucosal tissues following bacterial challenge are still limited. Towards to this end, here, we characterized the g-type lysozymes, Lyg1 and Lyg2 in turbot, and determined their expression patterns in mucosal barriers following different bacterial infection. The phylogenetic analysis revealed the turbot g-type lysozyme genes showed the closest relationship to Cynoglossus semilaevis. The two lysozyme genes showed different expression patterns following challenge. Lyg2 was significantly up-regulated in mucosal tissues following Vibrio anguillarum and Streptococcus iniae challenge, while Lyg1 showed a general trend of down-regulation. The significant mucosal expression signatures of g-type lysozyme genes indicated their key roles to prevent pathogen attachment and entry in the first line of host defense system. Further functional studies should be carried out to better characterize the availability of utilization of g-type lysozyme to increase the disease resistance in the mucosal surfaces and facilitate the disease resistant breeding selection. PMID:27189917

  17. Stomatin-like protein 2 of turbot Scopthalmus maximus: Gene cloning, expression profiling and immunoregulatory properties.

    PubMed

    Chi, Heng; Hu, Yong-Hua

    2016-02-01

    Stomatin-like protein 2 (SLP-2) is a novel and unusual member of the stomatin gene superfamily. In this study, we obtained a full-length SLP-2 (SmSLP-2) cDNA from turbot (Scopthalmus maximus) spleen cDNA library. The cDNA sequence of SmSLP-2 contains a 5'-UTR of 107 bp, an ORF of 1050 bp, and a 3'-UTR of 959 bp. The ORF encodes a putative protein of 349 residues, which has a calculated molecular mass of 38.7 kDa. The SmSLP-2 protein possesses a prohibitin-homology (PHB) domain (residues 40 to 198) and shares 72.4-87.6% overall sequence identity with that of the teleost species. The highest expression of SmSLP-2 mRNA was found in the skin, followed by the head kidney, gut, spleen, liver, heart, gill and muscle. Moreover, both viral and bacterial pathogen infection resulted in the up-regulation of SmSLP-2 mRNA in the turbot head kidney and spleen in vivo. Subcellular localization analysis indicated that the SmSLP-2 proteins are mainly located in the peripheral membrane of ZF4 cells. This study also demonstrated that SmSLP-2 modulates IL-2 expression via active NFκB signaling pathway, and is possibly involved in host immune defense against bacterial and viral pathogens. PMID:26806162

  18. Chronic rapamycin treatment on the nutrient utilization and metabolism of juvenile turbot (Psetta maxima).

    PubMed

    Wang, Qingchao; He, Gen; Mai, Kangsen; Xu, Wei; Zhou, Huihui; Wang, Xuan; Mei, Lin

    2016-01-01

    High dietary protein inclusion is necessary in fish feeds and also represents a major cost in the aquaculture industry, which demands improved dietary conversion into body proteins in fish. In mammals, the target of rapamycin (TOR) is a key nutritionally responsive molecule governing postprandial anabolism. However, its physiological significance in teleosts has not been fully examined. In the present study, we examined the nutritional physiology of turbot after chronic rapamycin inhibition. Our results showed that a 6-week inhibition of TOR using dietary rapamycin inclusion (30 mg/kg diet) reduced growth performance and feed utilization. The rapamycin treatment inhibited TOR signaling and reduced expression of key enzymes in glycolysis, lipogenesis, cholesterol biosynthesis, while increasing the expression of enzymes involved in gluconeogenesis. Furthermore, rapamycin treatment increased intestinal goblet cell number in turbot, while the expressions of Notch and Hes1 were down regulated. It was possible that stimulated goblet cell differentiation by rapamycin was mediated through Notch-Hes1 pathway. Therefore, our results demonstrate the important role of TOR signaling in fish nutritional physiology. PMID:27305975

  19. Effect of dietary vitamin E on the sperm quality of turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Xu, Houguo; Huang, Lina; Liang, Mengqing; Zheng, Keke; Wang, Xinxing

    2015-08-01

    A 3-month feeding experiment was conducted in an in-door seawater system to investigate the effect of dietary vitamin E (Ve) on the sperm quality of turbot ( Scophthalmus maximus). D-α-tocopherol acetate was supplemented to the basal (control) diet (65.14 mg kg-1 Ve) to obtain low and high levels of dietary Ve (244.60 mg kg-1, LVe; 721.60 mg kg-1, HVe). Compared with the control, sperm concentration was significantly increased in Ve-supplemented groups (LVe and HVe); while relative sperm volume and testis-somatic index were significantly increased in group HVe only. Sperm motility duration was significantly longer in group HVe than in the control, but no significant difference was observed in percent motility among groups. Sperm size, the uniformity of mitochondrial size, and the integrity of mitochondria cristae and plasma membrane were improved by dietary Ve, especially in HVe. The content of Ve in testis and liver as well as polyunsaturated fatty acids in sperm increased with dietary Ve. These results suggested that dietary Ve, especially at the high level (721.60 mg kg-1), significantly improved sperm concentration and motility duration and maintained normal sperm morphology of turbot.

  20. Cloning, expression and characterization of translationally controlled tumor protein (TCTP) gene from flatfish turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Guo, Huarong; Zhang, Shicui; Yin, Licheng; Guo, Bin; Wang, Shaojie

    2008-05-01

    A full-length cDNA encoding translationally controlled tumor protein of marine flatfish turbot ( Scophthalmus maximus), SmTCTP, was isolated with rapid amplification of cDNA Ends (RACE). SmTCTP consisted of a 5' untranslated region (UTR) of 84 bp, a 3' UTR of 451 bp and an open reading frame (ORF) of 513 bp, encoding a protein of 170 amino acid residues, which contained two signature sequences of TCTP family. The 5'UTR of SmTCTP started with a 5'-terminal oligopyrimidine tract (5'-TOP), a typical feature for translationally controlled mRNAs. The deduced amino acid sequence of SmTCTP was similar to the other known vertebrate TCTPs in a range of 58.8% to 64.1%. The length of fish TCTPs was diverse among species, e.g., TCP of turbot and sea perch ( Lateolabrax japonicus) is 170 aa in length, while that of zebrafish ( Danio rerio) and rohu ( Labeo rohita) is 171 aa in length. Northern blot analysis revealed that SmTCTP has only one type of mRNA. Its expression level in albino skin was slightly higher than that in normal skin. We constructed the pET30a- SmTCTP expression plasmid. The recombinant protein of His-tag SmTCTP was over-expressed in E. coli, purified and identified with peptide mass fingerprinting. These results may pave the way of further investigation of the biological function of TCTP in fish.

  1. Alaska Volcano Observatory

    USGS Publications Warehouse

    Venezky, Dina Y.; Murray, Tom; Read, Cyrus

    2008-01-01

    Steam plume from the 2006 eruption of Augustine volcano in Cook Inlet, Alaska. Explosive ash-producing eruptions from Alaska's 40+ historically active volcanoes pose hazards to aviation, including commercial aircraft flying the busy North Pacific routes between North America and Asia. The Alaska Volcano Observatory (AVO) monitors these volcanoes to provide forecasts of eruptive activity. AVO is a joint program of the U.S. Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO is one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about Augustine volcano and AVO at http://www.avo.alaska.edu.

  2. Trophic transfer and accumulation of TiO2 nanoparticles from clamworm (Perinereis aibuhitensis) to juvenile turbot (Scophthalmus maximus) along a marine benthic food chain.

    PubMed

    Wang, Zhenyu; Yin, Liyun; Zhao, Jian; Xing, Baoshan

    2016-05-15

    In the present work, we investigated the potential benthic trophic transfer of TiO2 nanoparticles (NPs) from clamworm (Perinereis aibuhitensis) to juvenile turbot (Scophthalmus maximus) and their related distribution and toxicity. TiO2 NPs (at 10, 50 and 100 mg/L) could be taken up by clamworms, and mainly accumulated in the lower-digestive tract. TiO2 NPs were able to transfer from clamworms to juvenile turbots. The accumulation of TiO2 NPs in juvenile turbots increased with increasing Ti contents in clamworms during the dietary exposure, however, no biomagnification (BMFs, 0.30-0.33) of TiO2 NPs was observed. For both dietary and waterborne exposure, accumulation of TiO2 NPs was higher in the gill, intestine and stomach of juvenile turbot, following by skin, liver, and muscle. During dietary exposure at Day 20, the growth of turbots was reduced, and abnormal symptoms of liver and spleen were detected. Moreover, both dietary (50 and 100 mg/L TiO2 NPs-treated clamworms) and waterborne (100 mg/L TiO2 NPs) exposures led to significantly lower protein and higher lipid contents, suggesting the nutrition quality reduction of turbots. The findings from this work highlighted the trophic transfer of TiO2 NPs in marine benthic food chain, leading to the potential negative impact on marine aquaculture and food quality. PMID:27010785

  3. Trophic transfer and accumulation of TiO2 nanoparticles from clamworm (Perinereis aibuhitensis) to juvenile turbot (Scophthalmus maximus) along a marine benthic food chain.

    PubMed

    Wang, Zhenyu; Yin, Liyun; Zhao, Jian; Xing, Baoshan

    2016-05-15

    In the present work, we investigated the potential benthic trophic transfer of TiO2 nanoparticles (NPs) from clamworm (Perinereis aibuhitensis) to juvenile turbot (Scophthalmus maximus) and their related distribution and toxicity. TiO2 NPs (at 10, 50 and 100 mg/L) could be taken up by clamworms, and mainly accumulated in the lower-digestive tract. TiO2 NPs were able to transfer from clamworms to juvenile turbots. The accumulation of TiO2 NPs in juvenile turbots increased with increasing Ti contents in clamworms during the dietary exposure, however, no biomagnification (BMFs, 0.30-0.33) of TiO2 NPs was observed. For both dietary and waterborne exposure, accumulation of TiO2 NPs was higher in the gill, intestine and stomach of juvenile turbot, following by skin, liver, and muscle. During dietary exposure at Day 20, the growth of turbots was reduced, and abnormal symptoms of liver and spleen were detected. Moreover, both dietary (50 and 100 mg/L TiO2 NPs-treated clamworms) and waterborne (100 mg/L TiO2 NPs) exposures led to significantly lower protein and higher lipid contents, suggesting the nutrition quality reduction of turbots. The findings from this work highlighted the trophic transfer of TiO2 NPs in marine benthic food chain, leading to the potential negative impact on marine aquaculture and food quality.

  4. Alaska's renewable energy potential.

    SciTech Connect

    Not Available

    2009-02-01

    This paper delivers a brief survey of renewable energy technologies applicable to Alaska's climate, latitude, geography, and geology. We first identify Alaska's natural renewable energy resources and which renewable energy technologies would be most productive. e survey the current state of renewable energy technologies and research efforts within the U.S. and, where appropriate, internationally. We also present information on the current state of Alaska's renewable energy assets, incentives, and commercial enterprises. Finally, we escribe places where research efforts at Sandia National Laboratories could assist the state of Alaska with its renewable energy technology investment efforts.

  5. Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland.

    PubMed

    Hanke, Dennis; Freuling, Conrad M; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R; Bøtner, Anette; Mettenleiter, Thomas C; Beer, Martin; Rasmussen, Thomas B; Müller, Thomas F; Höper, Dirk

    2016-07-01

    There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1-4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I - 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure in

  6. Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland.

    PubMed

    Hanke, Dennis; Freuling, Conrad M; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R; Bøtner, Anette; Mettenleiter, Thomas C; Beer, Martin; Rasmussen, Thomas B; Müller, Thomas F; Höper, Dirk

    2016-07-01

    There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1-4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I - 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure in

  7. Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland

    PubMed Central

    Hanke, Dennis; Freuling, Conrad M.; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R.; Bøtner, Anette; Mettenleiter, Thomas C.; Beer, Martin; Rasmussen, Thomas B.; Müller, Thomas F.; Höper, Dirk

    2016-01-01

    There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1–4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I – 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure

  8. Crustal structure beneath Central-Eastern Greenland

    NASA Astrophysics Data System (ADS)

    Reiche, S.; Thybo, H.; Reid, I.; Shulgin, A.

    2012-04-01

    Acquisition of geophysical data onshore Greenland is logistically complicated by the presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass. Previous seismic surveys have only been carried out offshore and near the coast of Greenland, where little information about the continental part of the crust could be gained. Aiming to improve our understanding about crustal thickness and composition below the Greenland ice cap, the TopoGreenland project was initiated to collect the first ever controlled source seismic data onshore Greenland. Wide-angle seismic data were acquired along an EW-trending profile, extending 310 km inland from the approximate edge of the stable ice cap near Scoresby Sund across the centre of the ice cap. In total, 348 Reftek Texan receivers recorded high-quality data from 8 equidistant shot points along the profile. Based on forward ray tracing modelling, a two-dimensional velocity model provides the first insight into the velocity structure beneath the Greenland ice sheet. Modelling results indicate a decrease of crustal thickness from 50 km below the centre of Greenland to 42 km in the eastern part of the profile. Relatively high lower crustal velocities (Vp 6.8 - 7.3) in the western part of the model may be related to past collisional tectonic events or to the passage of the Iceland mantle plume.

  9. Southwest coast of Greenland and Davis Strait

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image was taken by MODIS as it passed over the southwest coast of Greenland (right) and the Davis Strait (center and left). The Davis Strait connects Baffin Bay to the north and the Labrador Sea to the south, and separates Greenland from Baffin Island, Canada. The Davis Strait is part of the Northwest Passage, a navigable seaway connecting the Atlantic Ocean and the Pacific Ocean. The image shows the prevailing currents in the area, with the warm water of a branch of the North Atlantic Drift flowing northward along the Greenland coast, and the cold, iceberg-filled Labrador Current flowing southward along the Baffin Island coast.

  10. Alaska Library Directory, 1996.

    ERIC Educational Resources Information Center

    Jennings, Mary, Ed.

    This directory of Alaska's Libraries lists: members of the Alaska Library Association (AkLA) Executive Council and Committee Chairs; State Board of Education members; members of the Governor's Advisory Council on Libraries; school, academic and public libraries and their addresses, phone and fax numbers, and contact persons; personal,…

  11. Renewable Energy in Alaska

    SciTech Connect

    Not Available

    2013-03-01

    This report examines the opportunities, challenges, and costs associated with renewable energy implementation in Alaska and provides strategies that position Alaska's accumulating knowledge in renewable energy development for export to the rapidly growing energy/electric markets of the developing world.

  12. Alaska geothermal bibliography

    SciTech Connect

    Liss, S.A.; Motyka, R.J.; Nye, C.J.

    1987-05-01

    The Alaska geothermal bibliography lists all publications, through 1986, that discuss any facet of geothermal energy in Alaska. In addition, selected publications about geology, geophysics, hydrology, volcanology, etc., which discuss areas where geothermal resources are located are included, though the geothermal resource itself may not be mentioned. The bibliography contains 748 entries.

  13. Oxidants and anti-oxidants in turbot seminal plasma and their effects on sperm quality

    NASA Astrophysics Data System (ADS)

    Han, Mingming; Ding, Fuhong; Meng, Zhen; Lei, Jilin

    2015-08-01

    In this research, the concentration and activity of oxidants and anti-oxidants in turbot semen, and their effects on sperm quality were studied. The results showed that superoxide dismutase (SOD), catalase, glutathione reductase (GR), uric acid, vitamin E (VE) and vitamin C (VC) were more abundant in seminal plasma than in spermatozoa. The variation for each of them was specific. In seminal plasma, the activity of SOD and GR increased from November 15, November 30 to December 15, and then decreased on December 30. The concentrations of both VC and uric acid decreased during the first 3 sampling times and increased on December 30. The oxidants in seminal plasma accumulated to the highest on December 30. Lactic acid (LA) and ATP levels decreased to the lowest on December 30. The correlation analysis showed that GR had the significant positive relevance to sperm motility and VSL/VCL, while ·OH had negative relevance to them.

  14. East Asian origin of central Greenland last glacial dust: just one possible scenario?

    NASA Astrophysics Data System (ADS)

    Újvári, Gábor; Stevens, Thomas; Svensson, Anders; Klötzli, Urs Stephan; Manning, Christina; Németh, Tibor; Kovács, János

    2016-04-01

    Dust in Greenland ice cores is used to reconstruct the activity of dust emitting regions and atmospheric circulation for the last glacial period. However, the source dust material to Greenland over this period is the subject of considerable uncertainty. Here we use new clay mineral and Sr-Nd isotopic data from eleven loess samples collected around the Northern Hemisphere and compare the 87Sr/86Sr and 143Nd/144Nd isotopic signatures of fine (<10 μm) separates to existing Greenland ice core dust data (GISP2, GRIP; [1]; [2]). Smectite contents and kaolinite/chlorite (K/C) ratios allow exclusion of continental US dust emitting regions as potential sources, because of the very high (>3.6) K/C ratios and extremely high (>~70%) smectite contents. At the same time, Sr-Nd isotopic compositions demonstrate that ice core dust isotopic compositions can be explained by East Asian (Chinese loess) and/or Central/East Central European dust contributions. Central/East Central European loess Sr-Nd isotopic compositions overlap most with ice core dust, while the Sr isotopic signature of Chinese loess is slightly more radiogenic. Nevertheless, an admixture of 90‒10 % from Chinese loess and circum-Pacific volcanic material would also account for the Sr‒Nd isotopic ratios of central Greenland LGM dust. At the same time, sourcing of ice core dust from Alaska, continental US and NE Siberia seems less likely based on Sr and Nd isotopic signatures. The data demonstrate that currently no unique source discrimination for Greenland dust is possible using both published and our new data [3]. Thus, there is a need to identify more diagnostic tracers. Based on initial Hf isotope analyses of fine separates of three loess samples (continental US, Central Europe, China), an apparent dependence of Hf isotopic signatures on the relative proportions of radiogenic clay minerals (primarily illite) was found, as these fine dust fractions are apparently zircon-free. The observed difference between

  15. Immunolocalization of tumor necrosis factor alpha in turbot (Scophthalmus maximus, L.) tissues.

    PubMed

    Ronza, Paolo; Losada, Ana Paula; Villamarín, Antonio; Bermúdez, Roberto; Quiroga, María Isabel

    2015-08-01

    Tumor necrosis factor alpha (TNFα) is a cytokine involved in a broad spectrum of cellular and organismal responses. Its main function, as a potent pro-inflammatory mediator, has been demonstrated in numerous teleost species and there are many reports on the modulation of TNFα gene expression under pathological conditions. Nevertheless, there is still scarce knowledge about the tissue distribution and type of cells that express this cytokine in fish species, which would help to further investigate its biological activities. These studies are hampered by the lack of molecular markers for teleost that hinder the development of morphological techniques, like immunohistochemistry. The aim of this work was to develop an immunohistochemical technique for the detection of TNFα in paraffin-embedded organs from healthy turbot (Scophthalmus maximus), an economically-important marine fish species. A commercial anti-human TNFα antibody, whose specificity was confirmed by western blot analysis, was used. Immunoreactive cells were observed in higher numbers in the lymphohematopoietic organs, kidney, spleen and thymus, although TNFα-positive cells were also present in the digestive tract, liver, heart, gills and skin. Similarly to non-fish species, monocytes/macrophages appeared to be the main producers of this cytokine; nevertheless, the presence of immunoreactive rodlet cells in different tissues was also reported. The nature and distribution of the labeled cells appeared to be related with a strategic localization for defense response to antigenic challenge. The relative abundance of TNFα-positive cells in the lymphohematopoietic organs also suggests that this cytokine may have a broader role in the normal physiology of those organs. The immunohistochemical technique allowed the in-situ characterization of TNFα expression, representing a valid tool to investigate the immune response of turbot.

  16. The physiological performance and immune response of juvenile turbot (Scophthalmus maximus) to nitrite exposure.

    PubMed

    Jia, Rui; Liu, Bao-Liang; Han, Cen; Huang, Bin; Lei, Ji-Lin

    2016-01-01

    Nitrite (NO(2-)) is the most common toxic nitrogenous compound in aquatic environment. The aim of the present study was to investigate the effects of nitrite physiological performance and immune response of turbot. Fish were exposed to 0, 0.02, 0.08, 0.4 and 0.8 mM nitrite for 96 h. After 0, 24, 48 and 96 h of exposure, blood were collected to measure the levels of glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), alkaline phosphatase (ALP), total protein (TP), albumin (Alb), complement C3 (C3), complement C4 (C4), immunoglobulin M (IgM) and lysozyme (LYS); gill samples were taken to analyze mRNA levels of LYS, heat shock protein 70 (HSP 70), heat shock protein 90 (HSP 90), metallothionein (MT), toll-like receptor 3 (TLR-3), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and insulin-like growth factor I (IGF-I). The results showed that nitrite (0.4 and/or 0.8mM) significantly increased the levels of GPT, GOT, ALP, C3 and C4, reduced the levels of IgM and LYS, up-regulated the gene expressions of HSP 70, HSP 90, MT, TLR-3, TNF-α and IL-1β, and down-regulated the gene expressions of LYS and IGF-1 after 48 and 96 h of exposure. Based on the results, it can be concluded that high level nitrite exposure results in dysfunction of the blood physiology and immunity in turbot. Further, this study will be helpful to understand the mechanism of aquatic toxicology induced by nitrite in marine fish. PMID:26802553

  17. Rich Rogers Flying Over Greenland Icecap

    NASA Video Gallery

    Ihis is a view from the NASA P3 aircraft cockpit as it flies 1000 feet over the Greenland icecap during Operation Icebridge mission, which flies each March-May. The end of video shows an ice camp w...

  18. Transcriptomic profiling revealed the signatures of intestinal barrier alteration and pathogen entry in turbot (Scophthalmus maximus) following Vibrio anguillarum challenge.

    PubMed

    Gao, Chengbin; Fu, Qiang; Su, Baofeng; Zhou, Shun; Liu, Fengqiao; Song, Lin; Zhang, Min; Ren, Yichao; Dong, Xiaoyu; Tan, Fenghua; Li, Chao

    2016-12-01

    The mucosal immune system serves as the frontline barriers of host defense against pathogen infection, especially for the fishes, which are living in the pathogen rich aquatic environment. The intestine constitutes the largest surface body area in constantly contact with the external pathogens, and plays a vital role in the immune defense against inflammation and pathogen infection. Previous studies have revealed that fish intestine might serves as the portal of entry for Vibrio anguillarum. To characterize the immune actors and their associated immune activities in turbot intestine barrier during bacterial infection, here we examined the gene expression profiles of turbot intestine at three time points following experimental infection with V. anguillarum utilizing RNA-seq technology. A total of 122 million reads were assembled into 183,101 contigs with an average length of 1151 bp and the N50 size of 2302 bp. Analysis of differential gene expression between control and infected samples at 1 h, 4 h, and 12 h revealed 2079 significantly expressed genes. Enrichment and pathway analysis of the differentially expressed genes showed the centrality of the pathogen attachment and recognition, antioxidant/apoptosis, mucus barrier modification and immune activation/inflammation in the pathogen entry and host immune responses. The present study reported the novel gene expression patterns in turbot mucosal immunity, which were overlooked in previous studies. Our results can help to understand the mechanisms of turbot host defense, and may also provide foundation to identify the biomarkers for future selection of disease-resistant broodstock and evaluation of disease prevention and treatment options. PMID:27431928

  19. RNA-seq analysis of early enteromyxosis in turbot (Scophthalmus maximus): new insights into parasite invasion and immune evasion strategies.

    PubMed

    Ronza, Paolo; Robledo, Diego; Bermúdez, Roberto; Losada, Ana Paula; Pardo, Belén G; Sitjà-Bobadilla, Ariadna; Quiroga, María Isabel; Martínez, Paulino

    2016-07-01

    Enteromyxum scophthalmi, an intestinal myxozoan parasite, is the causative agent of a threatening disease for turbot (Scophthalmus maximus, L.) aquaculture. The colonisation of the digestive tract by this parasite leads to a cachectic syndrome associated with high morbidity and mortality rates. This myxosporidiosis has a long pre-patent period and the first detectable clinical and histopathological changes are subtle. The pathogenic mechanisms acting in the early stages of infection are still far from being fully understood. Further information on the host-parasite interaction is needed to assist in finding efficient preventive and therapeutic measures. Here, a RNA-seq-based transcriptome analysis of head kidney, spleen and pyloric caeca from experimentally-infected and control turbot was performed. Only infected fish with early signs of infection, determined by histopathology and immunohistochemical detection of E. scophthalmi, were selected. The RNA-seq analysis revealed, as expected, less intense transcriptomic changes than those previously found during later stages of the disease. Several genes involved in IFN-related pathways were up-regulated in the three organs, suggesting that the IFN-mediated immune response plays a main role in this phase of the disease. Interestingly, an opposite expression pattern had been found in a previous study on severely infected turbot. In addition, possible strategies for immune system evasion were suggested by the down-regulation of different genes encoding complement components and acute phase proteins. At the site of infection (pyloric caeca), modulation of genes related to different structural proteins was detected and the expression profile indicated the inhibition of cell proliferation and differentiation. These transcriptomic changes provide indications regarding the mechanisms of parasite attachment to and invasion of the host. The current results contribute to a better knowledge of the events that characterise the early

  20. Involvement of Acylated Homoserine Lactones (AHLs) of Aeromonas sobria in Spoilage of Refrigerated Turbot (Scophthalmus maximus L.)

    PubMed Central

    Li, Tingting; Cui, Fangchao; Bai, Fengling; Zhao, Guohua; Li, Jianrong

    2016-01-01

    One quorum sensing strain was isolated from spoiled turbot. The species was determined by 16S rRNA gene analysis and classical tests, named Aeromonas sobria AS7. Quorum-sensing (QS) signals (N-acyl homoserine lactones (AHLs)) were detected by report strains and their structures were further determined by GC-MS. The activity changes of AHLs on strain growth stage as well as the influence of different culture conditions on secretion activity of AHLs were studied by the punch method. The result indicated that strain AS7 could induce report strains to produce typical phenotypic response. N-butanoyl-dl-homoserine lactone (C4–HSL), N-hexanoyl-dl-homoserine lactone (C6–HSL), N-octanoyl-dl-homoserine lactone (C8–HSL), N-decanoyl-dl-homoserine lactone (C10–HSL), N-dodecanoyl-dl-homoserine lactone (C12–HSL) could be detected. The activities of AHLs were density-dependent and the max secretion level was at pH 8, sucrose culture, 1% NaCl and 32 h, respectively. The production of siderophore in strain AS7 was regulated by exogenous C8–HSL, rather than C6–HSL. Exogenous C4–HSL and C8–HSL accelerated the growth rate and population density of AS7 in turbot samples under refrigerated storage. However, according to the total viable counts and total volatile basic nitrogen (TVB-N) values of the fish samples, exogenous C6–HSL did not cause spoilage of the turbot fillets. In conclusion, our results suggested that QS was involved in the spoilage of refrigerated turbot. PMID:27420072

  1. RNA-seq analysis of early enteromyxosis in turbot (Scophthalmus maximus): new insights into parasite invasion and immune evasion strategies.

    PubMed

    Ronza, Paolo; Robledo, Diego; Bermúdez, Roberto; Losada, Ana Paula; Pardo, Belén G; Sitjà-Bobadilla, Ariadna; Quiroga, María Isabel; Martínez, Paulino

    2016-07-01

    Enteromyxum scophthalmi, an intestinal myxozoan parasite, is the causative agent of a threatening disease for turbot (Scophthalmus maximus, L.) aquaculture. The colonisation of the digestive tract by this parasite leads to a cachectic syndrome associated with high morbidity and mortality rates. This myxosporidiosis has a long pre-patent period and the first detectable clinical and histopathological changes are subtle. The pathogenic mechanisms acting in the early stages of infection are still far from being fully understood. Further information on the host-parasite interaction is needed to assist in finding efficient preventive and therapeutic measures. Here, a RNA-seq-based transcriptome analysis of head kidney, spleen and pyloric caeca from experimentally-infected and control turbot was performed. Only infected fish with early signs of infection, determined by histopathology and immunohistochemical detection of E. scophthalmi, were selected. The RNA-seq analysis revealed, as expected, less intense transcriptomic changes than those previously found during later stages of the disease. Several genes involved in IFN-related pathways were up-regulated in the three organs, suggesting that the IFN-mediated immune response plays a main role in this phase of the disease. Interestingly, an opposite expression pattern had been found in a previous study on severely infected turbot. In addition, possible strategies for immune system evasion were suggested by the down-regulation of different genes encoding complement components and acute phase proteins. At the site of infection (pyloric caeca), modulation of genes related to different structural proteins was detected and the expression profile indicated the inhibition of cell proliferation and differentiation. These transcriptomic changes provide indications regarding the mechanisms of parasite attachment to and invasion of the host. The current results contribute to a better knowledge of the events that characterise the early

  2. Involvement of Acylated Homoserine Lactones (AHLs) of Aeromonas sobria in Spoilage of Refrigerated Turbot (Scophthalmus maximus L.).

    PubMed

    Li, Tingting; Cui, Fangchao; Bai, Fengling; Zhao, Guohua; Li, Jianrong

    2016-01-01

    One quorum sensing strain was isolated from spoiled turbot. The species was determined by 16S rRNA gene analysis and classical tests, named Aeromonas sobria AS7. Quorum-sensing (QS) signals (N-acyl homoserine lactones (AHLs)) were detected by report strains and their structures were further determined by GC-MS. The activity changes of AHLs on strain growth stage as well as the influence of different culture conditions on secretion activity of AHLs were studied by the punch method. The result indicated that strain AS7 could induce report strains to produce typical phenotypic response. N-butanoyl-dl-homoserine lactone (C₄-HSL), N-hexanoyl-dl-homoserine lactone (C₆-HSL), N-octanoyl-dl-homoserine lactone (C₈-HSL), N-decanoyl-dl-homoserine lactone (C10-HSL), N-dodecanoyl-dl-homoserine lactone (C12-HSL) could be detected. The activities of AHLs were density-dependent and the max secretion level was at pH 8, sucrose culture, 1% NaCl and 32 h, respectively. The production of siderophore in strain AS7 was regulated by exogenous C₈-HSL, rather than C₆-HSL. Exogenous C₄-HSL and C₈-HSL accelerated the growth rate and population density of AS7 in turbot samples under refrigerated storage. However, according to the total viable counts and total volatile basic nitrogen (TVB-N) values of the fish samples, exogenous C₆-HSL did not cause spoilage of the turbot fillets. In conclusion, our results suggested that QS was involved in the spoilage of refrigerated turbot. PMID:27420072

  3. Involvement of Acylated Homoserine Lactones (AHLs) of Aeromonas sobria in Spoilage of Refrigerated Turbot (Scophthalmus maximus L.).

    PubMed

    Li, Tingting; Cui, Fangchao; Bai, Fengling; Zhao, Guohua; Li, Jianrong

    2016-07-13

    One quorum sensing strain was isolated from spoiled turbot. The species was determined by 16S rRNA gene analysis and classical tests, named Aeromonas sobria AS7. Quorum-sensing (QS) signals (N-acyl homoserine lactones (AHLs)) were detected by report strains and their structures were further determined by GC-MS. The activity changes of AHLs on strain growth stage as well as the influence of different culture conditions on secretion activity of AHLs were studied by the punch method. The result indicated that strain AS7 could induce report strains to produce typical phenotypic response. N-butanoyl-dl-homoserine lactone (C₄-HSL), N-hexanoyl-dl-homoserine lactone (C₆-HSL), N-octanoyl-dl-homoserine lactone (C₈-HSL), N-decanoyl-dl-homoserine lactone (C10-HSL), N-dodecanoyl-dl-homoserine lactone (C12-HSL) could be detected. The activities of AHLs were density-dependent and the max secretion level was at pH 8, sucrose culture, 1% NaCl and 32 h, respectively. The production of siderophore in strain AS7 was regulated by exogenous C₈-HSL, rather than C₆-HSL. Exogenous C₄-HSL and C₈-HSL accelerated the growth rate and population density of AS7 in turbot samples under refrigerated storage. However, according to the total viable counts and total volatile basic nitrogen (TVB-N) values of the fish samples, exogenous C₆-HSL did not cause spoilage of the turbot fillets. In conclusion, our results suggested that QS was involved in the spoilage of refrigerated turbot.

  4. Greenland's Coast in Holiday Colors

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Vibrant reds, emerald greens, brilliant whites, and pastel blues adorn this view of the area surrounding the Jakobshavn Glacier on the western coast of Greenland. The image is a false-color (near-infrared, green, blue) view acquired by the Multi-angle Imaging SpectroRadiometer's nadir camera. The brightness of vegetation in the near-infrared contributes to the reddish hues; glacial silt gives rise to the green color of the water; and blue-colored melt ponds are visible in the bright white ice. A scattering of small icebergs in Disco Bay adds a touch of glittery sparkle to the scene.

    The large island in the upper left is called Qeqertarsuaq. To the east of this island, and just above image center, is the outlet of the fast-flowing Jakobshavn (or Ilulissat) glacier. Jakobshavn is considered to have the highest iceberg production of all Greenland glaciers and is a major drainage outlet for a large portion of the western side of the ice sheet. Icebergs released from the glacier drift slowly with the ocean currents and pose hazards for shipping along the coast.

    The Multi-angle Imaging SpectroRadiometer views the daylit Earth continuously and the entire globe between 82 degrees north and 82 degrees south latitude is observed every 9 days. These data products were generated from a portion of the imagery acquired on June 18, 2003 during Terra orbit 18615. The image cover an area of about 254 kilometers x 210 kilometers, and use data from blocks 34 to 35 within World Reference System-2 path 10.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  5. Involvement of VAMP-2 in exocytosis of IL-1{beta} in turbot (Scophthalmus maximus) leukocytes after Vibrio anguillarum infection

    SciTech Connect

    Chai Yingmei; Huang Xiaohang . E-mail: xiaohanghuang@yahoo.ca; Cong Bailin; Liu Shenghao; Chen Kui; Li Guangyou; Gaisano, Herbert Y.

    2006-04-07

    Vibrio anguillarum is a major pathogen threatening the fish aquaculture in China. Infection of cultivated turbot (Scophthalmus maximus) with V. anguillarum induced rapid synthesis and secretion of IL-1{beta}, which initiates the innate immune response. SNARE proteins are known to regulate vesicular trafficking and fusion in all eukaryotes. Here, we determined whether SNARE proteins, specifically vesicle-associated membrane protein-2 (VAMP-2), are involved in regulated exocytosis of IL-1{beta} of leukocytes in marine fish. We show that VAMP-2 is present in turbot blood leukocytes, with nucleotide sequence identity of 88.2% and 93.0% to those of zebra fish and sea bass, respectively. After Vibrio infection, turbot leukocyte VAMP-2 was increased at the levels of transcription and translation in a temporal pattern coinciding with leukocyte IL-1{beta} secretion. Confocal microscopy localized VAMP-2 to vesicle structures in leukocytes. Taken together, our results suggest that VAMP-2 is involved in regulated exocytosis of cytokines in immunocytes in fish.

  6. Effects of chemical stress and food limitation on the energy reserves and growth of turbot, Scophthalmus maximus.

    PubMed

    Kerambrun, E; Henry, F; Rabhi, K; Amara, R

    2014-12-01

    The objective of the present study is to examine the growth and energetic performance of juvenile turbot after exposure to contaminated sediment and during the subsequent recovery period with or without food limitation. We designed a two-step experiment by first exposing juvenile turbot to harbour sediment for 26 days and then transferring them to clean sea water with different frequencies of feeding for 35 days. Without food limitation, fish previously exposed to contaminated sediment compensated for weight, length and lipid reserve losses; we did not record any differences in size, Fulton's K condition index and triacylglycerol/sterol (TAG/ST) ratio after the 35-day depuration period compared to the reference fish. This result could be related to the compensatory growth mechanism observed in a wide range of fish species following a period of growth depression. With food limitation during the 35-day depuration period, recovery growth was not sufficient to restore length and weight values similar to the reference fish. Moreover, turbot previously exposed to contaminated sediment and subsequently fed twice or once a week exhibited extremely low TAG/ST ratios, but the reference fish submitted to the same restrictive feeding conditions did not. This study indicates that juvenile fish affected by chemical pollution can improve their biological performance if pollution events are followed by a period of abundant food. However, if pollution events occur during periods of food scarcity, e.g. in winter, storage of energy reserves will be compromised. PMID:25015714

  7. Wnt/β-catenin signaling participates in the regulation of lipogenesis in the liver of juvenile turbot (Scophthalmus maximus L.).

    PubMed

    Liu, Dongwu; Mai, Kangsen; Zhang, Yanjiao; Xu, Wei; Ai, Qinghui

    2016-01-01

    In this study, the mechanism that Wnt/β-catenin signaling inhibits lipogenesis was investigated in the liver of juvenile turbot (Scophthalmus maximus L.) by LiCl or XAV939 treatment. Wnt/β-catenin signaling was activated by LiCl treatment or inhibited by XAV939 treatment through regulating the expression of glycogen synthase kinase-3β (GSK-3β) and Wnt10b. In addition, the expression of lipoprotein lipase (LPL), fatty acid synthetase (FAS), peroxisome proliferator-activated receptor γ (PPARγ), and CCAAT/enhancer binding protein α (C/EBPα) was inhibited by LiCl treatment, but induced by XAV939 treatment. In the plasma of juvenile turbot, the level of nonesterified fatty acid (NEFA), glycerol, triglyceride (TG), total cholesterol (TC), and low density lipoprotein cholesterol (LDL-C) was decreased by LiCl treatment, which was related to the decrease of the activity of LPL and FAS. Thus the inhibitory effect of Wnt/β-catenin signaling on lipogenesis was associated with the expression of key enzymes and transcriptional factors. Wnt/β-catenin signaling may participate in inhibiting lipogenesis by inhibiting the expression of PPARγ and C/EBPα in the liver of juvenile turbot.

  8. Inter-species transmission of viral hemorrhagic septicemia virus (VHSV) from turbot (Scophthalmus maximus) to rainbow trout (Onchorhynchus mykiss).

    PubMed

    Schönherz, Anna A; Lorenzen, Niels; Einer-Jensen, Katja

    2013-04-01

    Successful viral infection is a complex mechanism, involving many host-pathogen interactions that developed during coevolution of host and pathogen, and often result in host-species specificity. Nevertheless, many viruses are able to infect several host species and sporadically cross species barriers. The viral hemorrhagic septicemia virus (VHSV), a rhabdovirus with high economic impact on the aquaculture industry, has developed an exceptionally wide host range across marine and freshwater environments. Transmission of VHSV between host species therefore represents a potential risk for aquaculture, which currently is not addressed in biosecurity managements. The objective of this study was to investigate the inter-species transmission potential of VHSV and evaluate whether infected marine wild fish pose a potential risk on marine cultured rainbow trout. A cohabitation infection trial with turbot as donor and rainbow trout as recipient host species was conducted. Turbot were intraperitoneally injected with either a marine-adapted (MA) or a trout-adapted (TA) VHSV isolate and subsequently grouped with naïve rainbow trout. Both VHSV isolates were able to replicate and cause mortality in turbot, while only the TA isolate was able to cross the species barrier and infect rainbow trout with fatal outcome. The results demonstrate that a marine fish species can function as reservoir and transmitter of TA VHSV isolates.

  9. Identification and expression analysis of TLR2 in mucosal tissues of turbot (Scophthalmus maximus L.) following bacterial challenge.

    PubMed

    Liu, Fengqiao; Su, Baofeng; Gao, Chengbin; Zhou, Shun; Song, Lin; Tan, Fenghua; Dong, Xiaoyu; Ren, Yichao; Li, Chao

    2016-08-01

    The pathogen recognition receptors (PRRs), which can recognize the conserved pathogen-associated molecular patterns (PAMPs) of the bacteria, play key roles in the mucosal surfaces for pathogen recognition and activation of immune signaling pathways. However, our understanding of the PRRs and their activities in mucosal surfaces in the critical early time points during pathogen infection is still limited. Towards to this end, here, we sought to identify the Toll-like receptor 2 (TLR2) in turbot as well as its expression profiles in mucosal barriers following bacterial infection in the early time points. The full-length TLR2 transcript consists of open reading frame (ORF) of 2451 bp encoding the putative peptide of 816 amino acids. The phylogenetic analysis revealed the turbot TLR2 showed the closest relationship to Paralichthys olivaceus. The TLR2 mRNA expression could be detected in all examined tissues, with the most abundant expression level in liver, and the lowest expression level in skin. In addition, TLR2 showed different expression patterns following Vibrio anguillarum and Streptococcus iniae infection, but was up-regulated following both challenge, especially post S. iniae challenge. Characterization of TLR2 will probably contribute to understanding of a number of infectious diseases and broaden the knowledge of interactions between host and pathogen, which will eventually help in the development of novel intervention strategies for farming turbot. PMID:27368539

  10. Comparison of the morphometric dynamics of fast-growing and slow-growing strains of turbot Scophthalmus maximus

    NASA Astrophysics Data System (ADS)

    Wang, Xin'an; Ma, Aijun

    2015-07-01

    The dynamics of changes in body shape of fast-growing and slow-growing strains of turbot Scophthalmus maximus, and of the differences in body shape between the two strains, were evaluated from 3 to 27 months of age. The ratios of total length/body length, body width/body length and total length/body width were used as morphometric indices. The two strains exhibited different temporal trends in total length/body length but similar trends in body width/body length and total length/body width. Generally, body width/body length of the two strains increased with time and total length/body width decreased. Thus, the bodies of both fast-growing and slow-growing strains of turbot changed from a narrow to a more rounded shape. However, the ratio total length/body length was generally lower, body width/body length was mostly higher and total length/body width was consistently lower in the fast-growing strain than in the slow-growing strain. Correlation analysis of the three shape ratios with body weight showed that total length/body length and total length/body width were unsuitable, and that width/body length was suitable, for use as a phenotypic marker for selective breeding of turbot for growth in weight.

  11. Wnt/β-catenin signaling participates in the regulation of lipogenesis in the liver of juvenile turbot (Scophthalmus maximus L.).

    PubMed

    Liu, Dongwu; Mai, Kangsen; Zhang, Yanjiao; Xu, Wei; Ai, Qinghui

    2016-01-01

    In this study, the mechanism that Wnt/β-catenin signaling inhibits lipogenesis was investigated in the liver of juvenile turbot (Scophthalmus maximus L.) by LiCl or XAV939 treatment. Wnt/β-catenin signaling was activated by LiCl treatment or inhibited by XAV939 treatment through regulating the expression of glycogen synthase kinase-3β (GSK-3β) and Wnt10b. In addition, the expression of lipoprotein lipase (LPL), fatty acid synthetase (FAS), peroxisome proliferator-activated receptor γ (PPARγ), and CCAAT/enhancer binding protein α (C/EBPα) was inhibited by LiCl treatment, but induced by XAV939 treatment. In the plasma of juvenile turbot, the level of nonesterified fatty acid (NEFA), glycerol, triglyceride (TG), total cholesterol (TC), and low density lipoprotein cholesterol (LDL-C) was decreased by LiCl treatment, which was related to the decrease of the activity of LPL and FAS. Thus the inhibitory effect of Wnt/β-catenin signaling on lipogenesis was associated with the expression of key enzymes and transcriptional factors. Wnt/β-catenin signaling may participate in inhibiting lipogenesis by inhibiting the expression of PPARγ and C/EBPα in the liver of juvenile turbot. PMID:26545985

  12. Integrative Transcriptome, Genome and Quantitative Trait Loci Resources Identify Single Nucleotide Polymorphisms in Candidate Genes for Growth Traits in Turbot.

    PubMed

    Robledo, Diego; Fernández, Carlos; Hermida, Miguel; Sciara, Andrés; Álvarez-Dios, José Antonio; Cabaleiro, Santiago; Caamaño, Rubén; Martínez, Paulino; Bouza, Carmen

    2016-01-01

    Growth traits represent a main goal in aquaculture breeding programs and may be related to adaptive variation in wild fisheries. Integrating quantitative trait loci (QTL) mapping and next generation sequencing can greatly help to identify variation in candidate genes, which can result in marker-assisted selection and better genetic structure information. Turbot is a commercially important flatfish in Europe and China, with available genomic information on QTLs and genome mapping. Muscle and liver RNA-seq from 18 individuals was carried out to obtain gene sequences and markers functionally related to growth, resulting in a total of 20,447 genes and 85,344 single nucleotide polymorphisms (SNPs). Many growth-related genes and SNPs were identified and placed in the turbot genome and genetic map to explore their co-localization with growth-QTL markers. Forty-five SNPs on growth-related genes were selected based on QTL co-localization and relevant function for growth traits. Forty-three SNPs were technically feasible and validated in a wild Atlantic population, where 91% were polymorphic. The integration of functional and structural genomic resources in turbot provides a practical approach for QTL mining in this species. Validated SNPs represent a useful set of growth-related gene markers for future association, functional and population studies in this flatfish species. PMID:26901189

  13. Integrative Transcriptome, Genome and Quantitative Trait Loci Resources Identify Single Nucleotide Polymorphisms in Candidate Genes for Growth Traits in Turbot

    PubMed Central

    Robledo, Diego; Fernández, Carlos; Hermida, Miguel; Sciara, Andrés; Álvarez-Dios, José Antonio; Cabaleiro, Santiago; Caamaño, Rubén; Martínez, Paulino; Bouza, Carmen

    2016-01-01

    Growth traits represent a main goal in aquaculture breeding programs and may be related to adaptive variation in wild fisheries. Integrating quantitative trait loci (QTL) mapping and next generation sequencing can greatly help to identify variation in candidate genes, which can result in marker-assisted selection and better genetic structure information. Turbot is a commercially important flatfish in Europe and China, with available genomic information on QTLs and genome mapping. Muscle and liver RNA-seq from 18 individuals was carried out to obtain gene sequences and markers functionally related to growth, resulting in a total of 20,447 genes and 85,344 single nucleotide polymorphisms (SNPs). Many growth-related genes and SNPs were identified and placed in the turbot genome and genetic map to explore their co-localization with growth-QTL markers. Forty-five SNPs on growth-related genes were selected based on QTL co-localization and relevant function for growth traits. Forty-three SNPs were technically feasible and validated in a wild Atlantic population, where 91% were polymorphic. The integration of functional and structural genomic resources in turbot provides a practical approach for QTL mining in this species. Validated SNPs represent a useful set of growth-related gene markers for future association, functional and population studies in this flatfish species. PMID:26901189

  14. Involvement of VAMP-2 in exocytosis of IL-1 beta in turbot (Scophthalmus maximus) leukocytes after Vibrio anguillarum infection.

    PubMed

    Chai, Yingmei; Huang, Xiaohang; Cong, Bailin; Liu, Shenghao; Chen, Kui; Li, Guangyou; Gaisano, Herbert Y

    2006-04-01

    Vibrio anguillarum is a major pathogen threatening the fish aquaculture in China. Infection of cultivated turbot (Scophthalmus maximus) with V. anguillarum induced rapid synthesis and secretion of IL-1beta, which initiates the innate immune response. SNARE proteins are known to regulate vesicular trafficking and fusion in all eukaryotes. Here, we determined whether SNARE proteins, specifically vesicle-associated membrane protein-2 (VAMP-2), are involved in regulated exocytosis of IL-1beta of leukocytes in marine fish. We show that VAMP-2 is present in turbot blood leukocytes, with nucleotide sequence identity of 88.2% and 93.0% to those of zebra fish and sea bass, respectively. After Vibrio infection, turbot leukocyte VAMP-2 was increased at the levels of transcription and translation in a temporal pattern coinciding with leukocyte IL-1beta secretion. Confocal microscopy localized VAMP-2 to vesicle structures in leukocytes. Taken together, our results suggest that VAMP-2 is involved in regulated exocytosis of cytokines in immunocytes in fish.

  15. Alaska marine ice atlas

    SciTech Connect

    LaBelle, J.C.; Wise, J.L.; Voelker, R.P.; Schulze, R.H.; Wohl, G.M.

    1982-01-01

    A comprehensive Atlas of Alaska marine ice is presented. It includes information on pack and landfast sea ice and calving tidewater glacier ice. It also gives information on ice and related environmental conditions collected over several years time and indicates the normal and extreme conditions that might be expected in Alaska coastal waters. Much of the information on ice conditions in Alaska coastal waters has emanated from research activities in outer continental shelf regions under assessment for oil and gas exploration and development potential. (DMC)

  16. In vitro and in vivo evaluation of lactic acid bacteria of aquatic origin as probiotics for turbot (Scophthalmus maximus L.) farming.

    PubMed

    Muñoz-Atienza, Estefanía; Araújo, Carlos; Magadán, Susana; Hernández, Pablo E; Herranz, Carmen; Santos, Ysabel; Cintas, Luis M

    2014-12-01

    Turbot (Scophthalmus maximus L.) is an important commercial marine flatfish. Its production may be affected by bacterial diseases that cause severe economical losses, mainly tenacibaculosis and vibriosis, provoked by Tenacibaculum maritimum and Vibrio splendidus, respectively. An alternative or complementary strategy to chemotherapy and vaccination for the control of these diseases is the use of probiotics. In this work, we report the in vitro and in vivo potential of eight lactic acid bacteria (LAB), previously isolated from fish, seafood and fish products intended for human consumption, as turbot probiotics. Seven out of the eight LAB exerted direct antimicrobial activity against, at least, four strains of T. maritimum and V. splendidus. All LAB survived in seawater at 18 °C for 7 days, and withstood exposure to pH 3.0 and 10% (v/v) turbot bile; however, they differed in cell surface hydrophobicity (8.2-21.7%) and in their ability to adhere to turbot skin (1.2-21.7%) and intestinal (0.7-2.1%) mucus. Most of the tested strains inhibited the binding of turbot pathogens to the mucus. Leuconostoc mesenteroides subsp. cremoris SMM69 and Weissella cibaria P71 were selected based on their strong antimicrobial activity against T. maritimum and V. splendidus, good probiotic properties, and different adhesion ability to skin mucus and capacity to inhibit the adhesion of turbot pathogens to mucus. These two LAB strains were harmless when administered by bath to turbot larvae and juveniles; moreover, real-time PCR on the transcription levels of the immunity-related genes encoding IL-1β, TNF-α, lysozyme, C3, MHC-Iα and MHC-IIα in five organs (head-kidney, spleen, liver, intestine and skin) revealed the ability of these LAB to stimulate their expression in turbot juveniles, especially the non-specific immunity associated genes in mucosal tissues. Based on our results, Lc. cremoris SMM69 and W. cibaria P71 may be considered as suitable probiotic candidates for turbot

  17. In vitro and in vivo evaluation of lactic acid bacteria of aquatic origin as probiotics for turbot (Scophthalmus maximus L.) farming.

    PubMed

    Muñoz-Atienza, Estefanía; Araújo, Carlos; Magadán, Susana; Hernández, Pablo E; Herranz, Carmen; Santos, Ysabel; Cintas, Luis M

    2014-12-01

    Turbot (Scophthalmus maximus L.) is an important commercial marine flatfish. Its production may be affected by bacterial diseases that cause severe economical losses, mainly tenacibaculosis and vibriosis, provoked by Tenacibaculum maritimum and Vibrio splendidus, respectively. An alternative or complementary strategy to chemotherapy and vaccination for the control of these diseases is the use of probiotics. In this work, we report the in vitro and in vivo potential of eight lactic acid bacteria (LAB), previously isolated from fish, seafood and fish products intended for human consumption, as turbot probiotics. Seven out of the eight LAB exerted direct antimicrobial activity against, at least, four strains of T. maritimum and V. splendidus. All LAB survived in seawater at 18 °C for 7 days, and withstood exposure to pH 3.0 and 10% (v/v) turbot bile; however, they differed in cell surface hydrophobicity (8.2-21.7%) and in their ability to adhere to turbot skin (1.2-21.7%) and intestinal (0.7-2.1%) mucus. Most of the tested strains inhibited the binding of turbot pathogens to the mucus. Leuconostoc mesenteroides subsp. cremoris SMM69 and Weissella cibaria P71 were selected based on their strong antimicrobial activity against T. maritimum and V. splendidus, good probiotic properties, and different adhesion ability to skin mucus and capacity to inhibit the adhesion of turbot pathogens to mucus. These two LAB strains were harmless when administered by bath to turbot larvae and juveniles; moreover, real-time PCR on the transcription levels of the immunity-related genes encoding IL-1β, TNF-α, lysozyme, C3, MHC-Iα and MHC-IIα in five organs (head-kidney, spleen, liver, intestine and skin) revealed the ability of these LAB to stimulate their expression in turbot juveniles, especially the non-specific immunity associated genes in mucosal tissues. Based on our results, Lc. cremoris SMM69 and W. cibaria P71 may be considered as suitable probiotic candidates for turbot

  18. Libraries in Alaska: MedlinePlus

    MedlinePlus

    ... this page: https://medlineplus.gov/libraries/alaska.html Libraries in Alaska To use the sharing features on ... JavaScript. Anchorage University of Alaska Anchorage Alaska Medical Library 3211 Providence Drive Anchorage, AK 99508-8176 907- ...

  19. 75 FR 53331 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... Interest to Hadohdleekaga, Incorporated, for the Native village of Hughes, Alaska, pursuant to the Alaska... Hughes, Alaska, and are located in: Kateel River Meridian, Alaska T. 9 N., R. 23 E., Sec. 5....

  20. Crustal Structure in Central-Eastern Greenland

    NASA Astrophysics Data System (ADS)

    Shulgin, A.; Thybo, H.

    2013-12-01

    We present the seismic structure in the interior of Greenland based on the first measurements by the seismic refraction/wide angle reflection method. Previous seismic surveys have only been carried out offshore and near the coast of Greenland, where the crustal structure is affected by oceanic break-up and may not be representative of the interior of the island. Acquisition of geophysical data onshore Greenland is logistically complicated by the presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The EW-trending profile extends 310 km inland from the approximate edge of the stable ice cap near Scoresby Sund across the centre of the ice cap. The planned extension of the profile by use of OBSs and air gun shooting in Scoresbysund Fjord to the east coast of Greenland was unfortunately cancelled, because navigation was prevented by ice drift. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along the profile. Explosive charge sizes were 1 ton at the ends and ca. 500 kg along the profile, loaded with about 100 kg at 35-85 m depth in individual boreholes. Two-dimensional velocity model based on forward ray tracing and tomography modelling shows a decrease of crustal thickness from 47 km below the centre of Greenland in the western part to 40 km in the eastern part of the profile. Earlier studies show that crustal thickness further decreases eastward to ca. 30 km below the fjord system, but details of the changes are unknown. Relatively high lower crustal velocities (Vp 6.8 - 7.3) in the western part of the TopoGreenland profile may indicate past collision tectonics or may be related or to the passage of the Iceland mantle plume. The origin of the pronounced circum-Atlantic mountain ranges in Norway and eastern Greenland, which have

  1. Molecular Analysis of Endocrine Disruption in Hornyhead Turbot at Wastewater Outfalls in Southern California Using a Second Generation Multi-Species Microarray

    PubMed Central

    Baker, Michael E.; Vidal-Dorsch, Doris E.; Ribecco, Cataldo; Sprague, L. James; Angert, Mila; Lekmine, Narimene; Ludka, Colleen; Martella, Andrea; Ricciardelli, Eugenia; Bay, Steven M.; Gully, Joseph R.; Kelley, Kevin M.; Schlenk, Daniel; Carnevali, Oliana; Šášik, Roman; Hardiman, Gary

    2013-01-01

    Sentinel fish hornyhead turbot (Pleuronichthysverticalis) captured near wastewater outfalls are used for monitoring exposure to industrial and agricultural chemicals of ~ 20 million people living in coastal Southern California. Although analyses of hormones in blood and organ morphology and histology are useful for assessing contaminant exposure, there is a need for quantitative and sensitive molecular measurements, since contaminants of emerging concern are known to produce subtle effects. We developed a second generation multi-species microarray with expanded content and sensitivity to investigate endocrine disruption in turbot captured near wastewater outfalls in San Diego, Orange County and Los Angeles California. Analysis of expression of genes involved in hormone [e.g., estrogen, androgen, thyroid] responses and xenobiotic metabolism in turbot livers was correlated with a series of phenotypic end points. Molecular analyses of turbot livers uncovered altered expression of vitellogenin and zona pellucida protein, indicating exposure to one or more estrogenic chemicals, as well as, alterations in cytochrome P450 (CYP) 1A, CYP3A and glutathione S-transferase-α indicating induction of the detoxification response. Molecular responses indicative of exposure to endocrine disruptors were observed in field-caught hornyhead turbot captured in Southern California demonstrating the utility of molecular methods for monitoring environmental chemicals in wastewater outfalls. Moreover, this approach can be adapted to monitor other sites for contaminants of emerging concern in other fish species for which there are few available gene sequences. PMID:24086568

  2. Tissue Localization of Lymphocystis Disease Virus (LCDV) Receptor-27.8 kDa and Its Expression Kinetics Induced by the Viral Infection in Turbot (Scophthalmus maximus)

    PubMed Central

    Sheng, Xiuzhen; Wu, Ronghua; Tang, Xiaoqian; Xing, Jing; Zhan, Wenbin

    2015-01-01

    The 27.8 kDa membrane protein expressed in flounder (Paralichthys olivaceus) gill cells was proved to be a receptor mediating lymphocystis disease virus (LCDV) infection. In this study, SDS-PAGE and Western blotting demonstrated that 27.8 kDa receptor (27.8R) was shared by flounder and turbot (Scophthalmus maximus). Indirect immunofluorescence assay (IIFA) and immunohistochemistry showed that 27.8R was widely expressed in tested tissues of healthy turbot. The indirect enzyme-linked immunosorbent assay indicated that 27.8R expression was relatively higher in stomach, gill, heart, and intestine, followed by skin, head kidney, spleen, blood cells, kidney and liver, and lower in ovary and brain in healthy turbot, and it was significantly up-regulated after LCDV infection. Meanwhile, real-time quantitative PCR demonstrated that LCDV was detected in heart, peripheral blood cells, and head kidney at 3 h post infection (p.i.), and then in other tested tissues at 12 h p.i. LCDV copies increased in a time-dependent manner, and were generally higher in the tissues with higher 27.8R expression. Additionally, IIFA showed that 27.8R and LCDV were detected at 3 h p.i. in some leukocytes. These results suggested that 27.8R also served as a receptor in turbot, and LCDV can infect some leukocytes which might result in LCDV spreading to different tissues in turbot. PMID:26556346

  3. Tissue Localization of Lymphocystis Disease Virus (LCDV) Receptor-27.8 kDa and Its Expression Kinetics Induced by the Viral Infection in Turbot (Scophthalmus maximus).

    PubMed

    Sheng, Xiuzhen; Wu, Ronghua; Tang, Xiaoqian; Xing, Jing; Zhan, Wenbin

    2015-01-01

    The 27.8 kDa membrane protein expressed in flounder (Paralichthys olivaceus) gill cells was proved to be a receptor mediating lymphocystis disease virus (LCDV) infection. In this study, SDS-PAGE and Western blotting demonstrated that 27.8 kDa receptor (27.8R) was shared by flounder and turbot (Scophthalmus maximus). Indirect immunofluorescence assay (IIFA) and immunohistochemistry showed that 27.8R was widely expressed in tested tissues of healthy turbot. The indirect enzyme-linked immunosorbent assay indicated that 27.8R expression was relatively higher in stomach, gill, heart, and intestine, followed by skin, head kidney, spleen, blood cells, kidney and liver, and lower in ovary and brain in healthy turbot, and it was significantly up-regulated after LCDV infection. Meanwhile, real-time quantitative PCR demonstrated that LCDV was detected in heart, peripheral blood cells, and head kidney at 3 h post infection (p.i.), and then in other tested tissues at 12 h p.i. LCDV copies increased in a time-dependent manner, and were generally higher in the tissues with higher 27.8R expression. Additionally, IIFA showed that 27.8R and LCDV were detected at 3 h p.i. in some leukocytes. These results suggested that 27.8R also served as a receptor in turbot, and LCDV can infect some leukocytes which might result in LCDV spreading to different tissues in turbot.

  4. Tissue Localization of Lymphocystis Disease Virus (LCDV) Receptor-27.8 kDa and Its Expression Kinetics Induced by the Viral Infection in Turbot (Scophthalmus maximus).

    PubMed

    Sheng, Xiuzhen; Wu, Ronghua; Tang, Xiaoqian; Xing, Jing; Zhan, Wenbin

    2015-01-01

    The 27.8 kDa membrane protein expressed in flounder (Paralichthys olivaceus) gill cells was proved to be a receptor mediating lymphocystis disease virus (LCDV) infection. In this study, SDS-PAGE and Western blotting demonstrated that 27.8 kDa receptor (27.8R) was shared by flounder and turbot (Scophthalmus maximus). Indirect immunofluorescence assay (IIFA) and immunohistochemistry showed that 27.8R was widely expressed in tested tissues of healthy turbot. The indirect enzyme-linked immunosorbent assay indicated that 27.8R expression was relatively higher in stomach, gill, heart, and intestine, followed by skin, head kidney, spleen, blood cells, kidney and liver, and lower in ovary and brain in healthy turbot, and it was significantly up-regulated after LCDV infection. Meanwhile, real-time quantitative PCR demonstrated that LCDV was detected in heart, peripheral blood cells, and head kidney at 3 h post infection (p.i.), and then in other tested tissues at 12 h p.i. LCDV copies increased in a time-dependent manner, and were generally higher in the tissues with higher 27.8R expression. Additionally, IIFA showed that 27.8R and LCDV were detected at 3 h p.i. in some leukocytes. These results suggested that 27.8R also served as a receptor in turbot, and LCDV can infect some leukocytes which might result in LCDV spreading to different tissues in turbot. PMID:26556346

  5. Alaska telemedicine: growth through collaboration.

    PubMed

    Patricoski, Chris

    2004-12-01

    The last thirty years have brought the introduction and expansion of telecommunications to rural and remote Alaska. The intellectual and financial investment of earlier projects, the more recent AFHCAN Project and the Universal Service Administrative Company Rural Health Care Division (RHCD) has sparked a new era in telemedicine and telecommunication across Alaska. This spark has been flamed by the dedication and collaboration of leaders at he highest levels of organizations such as: AFHCAN member organizations, AFHCAN Office, Alaska Clinical Engineering Services, Alaska Federal Health Care Partnership, Alaska Federal Health Care Partnership Office, Alaska Native health Board, Alaska Native Tribal health Consortium, Alaska Telehealth Advisory Council, AT&T Alascom, GCI Inc., Health care providers throughout the state of Alaska, Indian Health Service, U.S. Department of Health and Human Services, Office of U.S. Senator Ted Steens, State of Alaska, U.S. Department of Homeland Security--United States Coast Guard, United States Department of Agriculture, United States Department of Defense--Air Force and Army, United States Department of Veterans Affairs, University of Alaska, and University of Alaska Anchorage. Alaska now has one of the largest telemedicine programs in the world. As Alaska moves system now in place become self-sustaining, and 2) collaborating with all stakeholders in promoting the growth of an integrated, state-wide telemedicine network.

  6. Alaska: A frontier divided

    SciTech Connect

    O'Dell, R. )

    1986-09-01

    The superlatives surrounding Alaska are legion. Within the borders of the 49th US state are some of the world's greatest concentrations of waterfowl, bald eagles, fur seals, walrus, sea lions, otters, and the famous Kodiak brown bear. Alaska features the highest peak of North America, the 20,320-foot Mount McKinley, and the longest archipelago of small islands, the Aleutians. The state holds the greatest percentage of protected wilderness per capita in the world. The expanse of some Alaskan glaciers dwarfs entire countries. Like the periodic advance and retreat of its glaciers, Alaska appears with some regularity on the national US agenda. It last achieved prominence when President Jimmy Carter signed the Alaska National Interest Lands Conservation Act in 1980. Since then the conflict between environmental protection and economic development has been played out throughout the state, and Congress is expected to turn to Alaskan issues again in its next sessions.

  7. Earthshots: Satellite images of environmental change – Petermann Glacier, Greenland

    USGS Publications Warehouse

    Adamson, Thomas

    2016-01-01

    This calving is normal, but it’s worth watching Petermann and other Greenland glaciers closely. Petermann is one of the major marine-terminating glaciers of Greenland. Ice loss from the Greenland Ice Sheet has increased recently. An article in Nature concluded that climate change may cause Petermann and other Greenland glaciers to contribute to sea level rise. Landsat helps glaciologists keep a close eye on this remote but significant glacier.

  8. Alaska looks HOT!

    SciTech Connect

    Belcher, J.

    1997-07-01

    Production in Alaska has been sluggish in recent years, with activity in the Prudhoe Bay region in the North Slope on a steady decline. Alaska North Slope (ANS) production topped out in 1988 at 2.037 MMbo/d, with 1.6 MMbo/d from Prudhoe Bay. This year operators expect to produce 788 Mbo/d from Prudhoe Bay, falling to 739 Mbo/d next year. ANS production as a whole should reach 1.3 MMbo/d this year, sliding to 1.29 MMbo/d in 1998. These declining numbers had industry officials and politicians talking about the early death of the Trans-Alaskan Pipeline System-the vital link between ANS crude and markets. But enhanced drilling technology coupled with a vastly improved relationship between the state government and industry have made development in Alaska more economical and attractive. Alaska`s Democratic Gov. Tommy Knowles is fond of telling industry {open_quotes}we`re open for business.{close_quotes} New discoveries on the North Slope and in the Cook Inlet are bringing a renewed sense of optimism to the Alaska exploration and production industry. Attempts by Congress to lift a moratorium on exploration and production activity in the Arctic National Wildlife Refuge (ANWR) have been thwarted thus far, but momentum appears to be with proponents of ANWR drilling.

  9. Polar continental margins: Studies off East Greenland

    NASA Astrophysics Data System (ADS)

    Mienert, J.; Thiede, J.; Kenyon, N. H.; Hollender, F.-J.

    The passive continental margin off east Greenland has been shaped by tectonic and sedimentary processes, and typical physiographic patterns have evolved over the past few million years under the influence of the late Cenozoic Northern Hemisphere glaciations. The Greenland ice shield has been particularly affected.GLORIA (Geological Long Range Inclined Asdic), the Institute of Oceanographic Sciences' (IOS) long-range, side-scan sonar, was used on a 1992 RV Livonia cruise to map large-scale changes in sedimentary patterns along the east Greenland continental margin. The overall objective of this research program was to determine the variety of large-scale seafloor processes to improve our understanding of the interaction between ice sheets, current regimes, and sedimentary processes. In cooperation with IOS and the RV Livonia, a high-quality set of seafloor data has been produced. GLORIA'S first survey of east Greenland's continental margin covered several 1000- × 50-km-wide swaths (Figure 1) and yielded an impressive sidescan sonar image of the complete Greenland Basin and margin (about 250,000 km2). A mosaic of the data was made at a scale of 1:375,000. The base map was prepared with a polar stereographic projection having a standard parallel of 71°.

  10. Clouds enhance Greenland ice sheet meltwater runoff

    NASA Astrophysics Data System (ADS)

    Van Tricht, Kristof; Lhermitte, Stef; Lenaerts, Jan T. M.; Gorodetskaya, Irina V.; L'Ecuyer, Tristan S.; Noël, Brice; van den Broeke, Michiel R.; Turner, David D.; van Lipzig, Nicole P. M.

    2016-04-01

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2) W m‑2. Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise.

  11. Clouds enhance Greenland ice sheet meltwater runoff.

    PubMed

    Van Tricht, K; Lhermitte, S; Lenaerts, J T M; Gorodetskaya, I V; L'Ecuyer, T S; Noël, B; van den Broeke, M R; Turner, D D; van Lipzig, N P M

    2016-01-12

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2) W m(-2). Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise.

  12. Clouds enhance Greenland ice sheet meltwater runoff

    NASA Astrophysics Data System (ADS)

    Van Tricht, Kristof; Lhermitte, Stef; Lenaerts, Jan T. M.; Gorodetskaya, Irina V.; L'Ecuyer, Tristan S.; Noël, Brice; van den Broeke, Michiel R.; Turner, David D.; van Lipzig, Nicole P. M.

    2016-04-01

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2) W m-2. Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise.

  13. Clouds enhance Greenland ice sheet meltwater runoff

    NASA Astrophysics Data System (ADS)

    van Tricht, K.; Lhermitte, S.; Lenaerts, J. T. M.; Gorodetskaya, I. V.; L'Ecuyer, T. S.; Noël, B.; van den Broeke, M. R.; Turner, D. D.; van Lipzig, N. P. M.

    2016-01-01

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (+/-5.2) W m-2. Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise.

  14. Clouds enhance Greenland ice sheet meltwater runoff

    PubMed Central

    Van Tricht, K.; Lhermitte, S.; Lenaerts, J. T. M.; Gorodetskaya, I. V.; L'Ecuyer, T. S.; Noël, B.; van den Broeke, M. R.; Turner, D. D.; van Lipzig, N. P. M.

    2016-01-01

    The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2) W m−2. Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise. PMID:26756470

  15. Airborne Laser Mapping of Greenland

    SciTech Connect

    Krabill, W.B.; Thomas, R.H.; Martin, C.F.; Sonntag, J.G.

    1996-10-01

    The Polar ice sheets contain enough water to raise Earth`s sea level by some 70 m. It is not clear whether changes in these ice sheets are contributing to the current rise. Ice sheet mass balance estimates can be obtained by monitoring the topography of selected Polar regions. The Arctic Ice Mapping (AIM) Project is a continuing program designed to provide a record of the absolute height of representative Arctic ice sheets. Using the Global Positioning System (GPS), aircraft flight lines may be duplicated with sufficient tolerance to provide repeated laser elevation measurements from one year to another. The raw GPS measurements are re-processed post-mission to provide sub-10 cm trajectories for each aircraft flight. This program began in 1991 with a proof-of-concept mission to Greenland. The data from this mission demonstrates 20 cm repeatability, principally due to the limited GPS constellation available. Refinements in all phases of the program (software, law and GPS hardware, and a complete GPS constellation) have yielded 10 cm repeatability in data from subsequent years, which includes probable geophysical change in the surface due to storm events and wind drift. 5 refs., 5 figs., 2 tabs.

  16. Immunological responses of turbot (Psetta maxima) to nodavirus infection or polyriboinosinic polyribocytidylic acid (pIC) stimulation, using expressed sequence tags (ESTs) analysis and cDNA microarrays.

    PubMed

    Park, Kyoung C; Osborne, Jane A; Montes, Ariana; Dios, Sonia; Nerland, Audun H; Novoa, Beatriz; Figueras, Antonio; Brown, Laura L; Johnson, Stewart C

    2009-01-01

    To investigate the immunological responses of turbot to nodavirus infection or pIC stimulation, we constructed cDNA libraries from liver, kidney and gill tissues of nodavirus-infected fish and examined the differential gene expression within turbot kidney in response to nodavirus infection or pIC stimulation using a turbot cDNA microarray. Turbot were experimentally infected with nodavirus and samples of each tissue were collected at selected time points post-infection. Using equal amount of total RNA at each sampling time, we made three tissue-specific cDNA libraries. After sequencing 3230 clones we obtained 3173 (98.2%) high quality sequences from our liver, kidney and gill libraries. Of these 2568 (80.9%) were identified as known genes and 605 (19.1%) as unknown genes. A total of 768 unique genes were identified. The two largest groups resulting from the classification of ESTs according to function were the cell/organism defense genes (71 uni-genes) and apoptosis-related process (23 uni-genes). Using these clones, a 1920 element cDNA microarray was constructed and used to investigate the differential gene expression within turbot in response to experimental nodavirus infection or pIC stimulation. Kidney tissue was collected at selected times post-infection (HPI) or stimulation (HPS), and total RNA was isolated for microarray analysis. Of the 1920 genes studied on the microarray, we identified a total of 121 differentially expressed genes in the kidney: 94 genes from nodavirus-infected animals and 79 genes from those stimulated with pIC. Within the nodavirus-infected fish we observed the highest number of differentially expressed genes at 24 HPI. Our results indicate that certain genes in turbot have important roles in immune responses to nodavirus infection and dsRNA stimulation.

  17. Food and feeding habits of juvenile flounder Platichthys flesus (L.), abd turbot Scophthalmus maximus L. in the åland archipelago, northern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Aarnio, Katri; Bonsdorff, Erik; Rosenback, Nina

    1996-12-01

    The food choice of juvenile flounder ( Platichthys flesus) and turbot ( Scophthalmus maximus) was studied in the northern Baltic Sea during the years 1988, 1989, 1994 and 1995. The diet included organisms from 30 species/taxa in flounder (n = 306) and 10 species/taxa in turbot (n = 41). Flounder ⩽ 45 mm mainly consumed meiofauna (dominating taxon: Harpacticoida, Copepoda) and larger fish (46-101 mm) consumed macrofauna (dominating taxa: Oligochaeta, Amphipoda and Chironomidae). In terms of biomass, macrofauna dominated for all sizes of flounders, and meiofauna was important only for the smallest fish. A strong seasonal variation could be detected in the diet. In spring, macrofauna dominated for all size classes of fish (only fish > 30 mm were caught in spring), while in summer and autumn meiofauna dominated the diets for fish ⩽ 45 mm in size. Juvenile turbot (22-88 mm) consumed macrofauna and small fish. Turbot ⩽ 30 mm consumed mainly amphipods, while > 30 mm turbot consumed mysid shrimps, amphipods and fish. The ontogenetic shift from meio- to macrofauna-sized prey in flounders occurs at a larger fish size in the northern Baltic Sea than reported in other areas, possibly depending on the increased relative importance of meiofauna in the northern Baltic. The seasonal variation in the diet could be due to seasonally changing abundances in the zoobenthos, or for the small fish (1-group, spring), to switching from meio- to macrofauna in order to optimize their energy gain. The 0-group flounders consumed meiofauna for a long period, possibly due to a learning-process or simply due to easy availability of meiofauna. Turbot has a much larger mouth gap than flounders, thus allowing them to consume macrofauna from the beginning of their benthic life.

  18. Alaska Resource Data File: Chignik quadrangle, Alaska

    USGS Publications Warehouse

    Pilcher, Steven H.

    2000-01-01

    Descriptions of the mineral occurrences can be found in the report. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska. There is a website from which you can obtain the data for this report in text and Filemaker Pro formats

  19. Greenland unveils terms for offshore licenses

    SciTech Connect

    Not Available

    1992-04-20

    This paper reports that Greenland has spelled out terms for its first round of offshore licensing. The action off western Greenland could lead to the first oil and gas exploration there since an unsuccessful campaign in the 1970s. The Mineral Resources Administration (MRA) for Greenland pegged exploration license terms on 133 blocks, all south of the 66th parallel, at 10 years with options for 2 year extensions to a maximum of 6 more years. The license can cover as many as six blocks. In the first 3 year period companies will have only a seismic obligation of 1,588 km per six blocks. For the second 3 year period there will be a one well obligation and one well in each subsequent 2 year periods.

  20. Fatal outbreak of botulism in Greenland.

    PubMed

    Hammer, Tóra Hedinsdottir; Jespersen, Sanne; Kanstrup, Jakob; Ballegaard, Vibe Cecilie; Kjerulf, Anne; Gelvan, Allan

    2015-03-01

    Botulism commonly occurs when the anaerobic, gram-positive bacterium Clostridium botulinum, under suitable conditions, produces botulinum neurotoxins. Named A-F, these toxins are the immediate causative agent of the clinical symptoms of symmetrical, descending neurological deficits, including respiratory muscle paralysis. We present five cases of foodborne botulism occurring in Greenland, two with fatal outcome, caused by ingestion of tradionally preserved eider fowl. In the cases of the survivors, antitoxin and supportive care, including mechanical ventilation, were administered. In these cases recovery was complete. Microbiological assays, including toxin neutralization bioassay, demonstrated the presence of neurotoxin E in two survivors. The third survivor was shown by PCR to have the BoNT type E gene in faeces. This is the first report of cases of fatal botulism in Greenland. It underscores the importance of prompt coordinated case management effort in a geographically isolated area such as Greenland.

  1. Lead Sources in Human Diet in Greenland

    PubMed Central

    Bjerregaard, Peter; Johansen, Poul; Mulvad, Gert; Pedersen, Henning Sloth; Hansen, Jens C.

    2004-01-01

    Although blood lead levels have declined in Greenland, they are still elevated despite the fact that lead levels in the Greenland environment are very low. Fragments of lead shot in game birds have been suggested as an important source of dietary exposure, and meals of sea birds, particularly eider, contain high concentrations of lead. In a cross-sectional population survey in Greenland in 1993–1994, blood lead adjusted for age and sex was found to be associated with the reported consumption of sea birds. Participants reporting less than weekly intake of sea birds had blood lead concentrations of approximately 75 μg/L, whereas those who reported eating sea birds several times a week had concentrations of approximately 110 μg/L, and those who reported daily intake had concentrations of 170 μg/L (p = 0.01). Blood lead was not associated with dietary exposure to other local or imported food items. PMID:15531433

  2. Late Pliocene deglaciation of Southern Greenland

    NASA Astrophysics Data System (ADS)

    Walczak, M. H.; Carlson, A. E.; Stoner, J. S.; Hatfield, R. G.; Wolhowe, M. D.; Mathias, A.

    2015-12-01

    Predicting the response of the remaining Antarctic and Greenland ice sheets to increasing atmospheric greenhouse gas concentrations is an important goal of climate science. The late Pliocene (3.3-3.0 Ma; formerly the middle Pliocene) may offer a natural quasi-analogue to climate in the upcoming centuries: CO2 levels were ~400 PPM, global surface temperatures were 2-3 degrees higher, and sea level was likely at least 6 m higher than today. Yet little is currently known about the history of the pre-Quaternary Greenland ice sheet. IODP Expedition 303 site U1307 at 2575 m depth on the Eirik Ridge extends back to 3.4 Ma, capturing the late-Pliocene warm period adjacent to the southern Greenland ice sheet. Ice-rafted debris records, interpreted on a paleomagnetic reversal age model, suggest roughly 40 ka cyclicity of between ~5% and ~40% sand. Between ~3.3 and 3.2 Ma there is a significant change in lithology characterized by an abrupt reduction in magnetic susceptibility, during which time the sand fraction remains below 10%. Assuming a magnetite mineralogy, hysteresis ratios support a much finer magnetic assemblage of unique provenance in this interval; Mrs/Ms values of the silt fraction range from ~0.2-0.25, compared to ~0.1 in the sediments above and below. The origin this material will be discussed, although this observation is unambiguously consistent with the disappearance of silt transported from the southern Greenland ice sheet. The lack of Greenlandic source material observed in this interval is unique in the last 3.4 Ma at this location, and may indicate full deglaciation of southern Greenland in the late Pliocene.

  3. Towards Greenland Glaciation: cumulative or abrupt transition?

    NASA Astrophysics Data System (ADS)

    Tan, Ning; Dumas, Christophe; Ladant, Jean-Baptiste; Ramstein, Gilles; Contoux, Camille

    2016-04-01

    During the mid-Pliocene warming period (3-3.3 Ma BP), global annual mean temperature is warmer by 2-3 degree than pre-industrial. Greenland ice sheet volume is supposed to be a 50% reduction compared to nowadays [Haywood et al. 2010]. Around 2.7-2.6 Ma BP, just ~ 500 kyr after the warming peak of mid-Pliocene, there is already full Greenland Glaciation [Lunt et al. 2008]. How does Greenland ice sheet evolve from a half size to a glaciation level during 3 Ma - 2.5 Ma? Data show that there is a decreasing trend of atmospheric CO2 concentration from 3 Ma to 2.5 Ma [Seki et al.2010; Bartoli et al. 2011; Martinez et al. 2015]. However, a recent study [Contoux et al. 2015] suggests that a lowering of CO2 is not sufficient to initiate a perennial glaciation on Greenland and must be combined to low summer insolation, to preserve the ice sheet during insolation maximum, suggesting a cumulative process. In order to diagnose whether the ice sheet build-up is an abrupt event or a cumulative process, we carry on, for the first time, a transient simulation of climate and ice sheet evolutions from 3 Ma to 2.5 Ma. This strategy enables to investigate waxing and waning of the ice sheet during several orbital cycles. To reach this goal, we use a tri-dimensional interpolation method designed by Ladant et al. (2014) which combines the evolution of CO2 concentration, orbital parameters and Greenland ice sheet sizes in an off-line way by interpolating snapshots simulations. Thanks to this new method, we can build a transient like simulation through asynchronous coupling between GCM and ice sheet model. With this method, we may consistently answer the question of the build-up of Greenland: abrupt or cumulative process.

  4. Quaternary vertebrates from Greenland: A review

    NASA Astrophysics Data System (ADS)

    Bennike, Ole

    Remains of fishes, birds and mammals are rarely reported from Quaternary deposits in Greenland. The oldest remains come from Late Pliocene and Early Pleistocene deposits and comprise Atlantic cod, hare, rabbit and ringed seal. Interglacial and interstadial deposits have yielded remains of cod, little auk, collared lemming, ringed seal, reindeer and bowhead whale. Early and Mid-Holocene finds include capelin, polar cod, red fish, sculpin, three-spined stickleback, Lapland longspur, Arctic hare, collared lemming, wolf, walrus, ringed seal, reindeer and bowhead whale. It is considered unlikely that vertebrates could survive in Greenland during the peak of the last glaciation, but many species had probably already immigrated in the Early Holocene.

  5. Flood frequency in Alaska

    USGS Publications Warehouse

    Childers, J.M.

    1970-01-01

    Records of peak discharge at 183 sites were used to study flood frequency in Alaska. The vast size of Alaska, its great ranges of physiography, and the lack of data for much of the State precluded a comprehensive analysis of all flood determinants. Peak stream discharges, where gaging-station records were available, were analyzed for 2-year, 5-year, 10-year, 25-year, and 50-year average-recurrence intervals. A regional analysis of the flood characteristics by multiple-regression methods gave a set of equations that can be used to estimate floods of selected recurrence intervals up to 50 years for any site on any stream in Alaska. The equations relate floods to drainage-basin characteristics. The study indicates that in Alaska the 50-year flood can be estimated from 10-year gaging- station records with a standard error of 22 percent whereas the 50-year flood can be estimated from the regression equation with a standard error of 53 percent. Also, maximum known floods at more than 500 gaging stations and miscellaneous sites in Alaska were related to drainage-area size. An envelope curve of 500 cubic feet per second per square mile covered all but 2 floods in the State.

  6. Late Holocene expansion of Istorvet ice cap, Liverpool Land, east Greenland

    NASA Astrophysics Data System (ADS)

    Lowell, Thomas V.; Hall, Brenda L.; Kelly, Meredith A.; Bennike, Ole; Lusas, Amanda R.; Honsaker, William; Smith, Colby A.; Levy, Laura B.; Travis, Scott; Denton, George H.

    2013-03-01

    The Greenland Ice Sheet is undergoing dynamic changes that will have global implications if they continue into the future. In this regard, an understanding of how the ice sheet responded to past climate changes affords a baseline for anticipating future behavior. Small, independent ice caps adjacent to the Greenland Ice Sheet (hereinafter called "local ice caps") are sensitive indicators of the response of Greenland ice-marginal zones to climate change. Therefore, we reconstructed late Holocene ice-marginal fluctuations of the local Istorvet ice cap in east Greenland, using radiocarbon dates of subfossil plants, 10Be dates of surface boulders, and analyses of sediment cores from both threshold and control lakes. During the last termination, the Istorvet ice cap had retreated close to its maximum Holocene position by ˜11,730 cal yr BP. Radiocarbon dates of subfossil plants exposed by recent recession of the ice margin indicate that the Istorvet cap was smaller than at present from AD 200 to AD 1025. Sediments from a threshold lake show no glacial input until the ice cap advanced to within 365 m of its Holocene maximum position by ˜AD 1150. Thereafter the ice cap remained at or close to this position until at least AD 1660. The timing of this, the most extensive of the Holocene, expansion is similar to that recorded at some glaciers in the Alps and in southern Alaska. However, in contrast to these other regions, the expansion in east Greenland at AD 1150 appears to have been very close to, if not at, a maximum Holocene value. Comparison of the Istorvet ice-cap fluctuations with Holocene glacier extents in Southern Hemisphere middle-to-high latitude locations on the Antarctic Peninsula and in the Andes and the Southern Alps suggests an out-of-phase relationship. If correct, this pattern supports the hypothesis that a bipolar see-saw of oceanic and/or atmospheric circulation during the Holocene produced asynchronous glacier response at some localities in the two

  7. [Visualization of the chilling storage time for turbot flesh based on hyperspectral imaging technique].

    PubMed

    Zhu, Feng-Le; Zhang, Hai-Liang; Shao, Yong-Ni; He, Yong

    2014-07-01

    This study proposed a new method using visible and near infrared (Vis/NIR) hyperspectral imaging for the detection and visualization of the chilling storage time for turbot flesh rapid and nondestructively. A total of 160 fish samples with 8 different storage days were collected for hyperspectral image scanning, and mean spectra were extracted from the region of interest (ROD inside each image. Partial least squares regression (PLSR) was applied as calibration method to correlate the spectral data and storage time for the 120 samples in calibration set. Then the PLSR model was used to predict the storage time for the 40 prediction samples, which achieved accurate results with determination coefficient (R2) of 0.966 2 and root mean square error of prediction (RMSEP) of 0.679 9 d. Finally, the storage time of each pixel in the hyperspectral images for all prediction samples was predicted and displayed in different colors for visualization based on pseudo-color images with the aid of an IDL program. The results indicated that hyperspectral imaging technique combined with chemometrics and image processing allows the determination and visualization of the chilling storage time for fish, displaying fish freshness status and distribution vividly and laying a foundation for the automatic processing of aquatic products.

  8. Digestive enzyme activities of turbot (Scophthalmus maximus L.) during early developmental stages under culture condition.

    PubMed

    Tong, X H; Xu, S H; Liu, Q H; Li, J; Xiao, Z Z; Ma, D Y

    2012-06-01

    Digestive enzyme activities were analysed in turbot (Scophthalmus maximus) from hatching until 60 days after hatching (DAH). Trypsin sharply increased to the climax at 17 DAH and decreased until 31 DAH followed by a stable level thereafter. Amylase was determined at 4 DAH, reached the maximum value at 19 DAH and declined sharply to 39 DAH and remained at a low level thereafter, suggesting the carbohydrate component should remain at a low level in formulated diets. Pepsin was detected at 9 DAH and increased to 34 DAH and then remained at a stable level. The above results revealed pancreatic enzymes are no longer main enzymes for food digestion after the formation of functional stomach. Leucine-alanine peptidase (Leu-ala) and alkaline phosphatase (AP) and leucine aminopeptidase N (LAP) were found in newly hatched larvae. Both AP and LAP activities markedly increased to 23 DAH, decreased abruptly to 50 DAH and increased gradually to 60 DAH. Leu-ala reached the plateau from 23 to 39 DAH, followed by a decline to 46 DAH and an increase until 60 DAH. The brush border membrane (BBM)-bound enzyme activities increased from 30% at 31 DAH to 81% at 38 DAH of the total activities, indicating the maturation of intestinal tract.

  9. Turbot Scophthalmus maximus: stocking density on growth, pigmentation and feed conversion

    NASA Astrophysics Data System (ADS)

    Ma, Aijun; Chen, Chao; Lei, Jilin; Chen, Siqing; Zhuang, Zhimeng; Wang, Yingeng

    2006-09-01

    Juvenile turbot ( Scophthalmus maximus) were reared in five different experiment groups in the initial stock densities at 0.28, 0.87, 1.12, 1.16, 2.75 kg/m2 respectively for the study of the density effect on growth, pigmentation and feed coefficient rate. The experiment lasted for 60 days with final stock densities at 1.91, 6.31, 8.86, 11.97, 17.67 kg/m2 respectively. Result showed that, in the same experiment condition, the stocking density has a positive effect on growth in low density and negative in high density. The SGR (special growth rate) was 3.189, 3.304, 3.447, 3.341, and 3.087 respectively. The uniformity of weight distributing among experiment groups decreased with increasing density. The stocking density had positive effect on feed coefficient rate. Group 1 had the least feed coefficient rate 0.96, and highest at 1.25 in Group 5, the highest density group. High stocking density inhibited the growth and increased the feed coefficient rate. The stocking density had negative relationship to pigmentation improvement for whitened fish.

  10. First Younger Dryas moraines in Greenland

    NASA Astrophysics Data System (ADS)

    Funder, Svend; Larsen, Nicolaj K.; Linge, Henriette; Möller, Per; Schomacker, Anders; Fabel, Derek; Kjær, Kurt H.; Xu, Sheng

    2016-04-01

    Over the Greenland ice sheet the Younger Dryas (YD) cold climate oscillation (12.9-11.7 kaBP) began with up to 10°C drop in temperatures and ended with up to 12°C abrupt warming. In the light of the present warming and melting of the ice sheet, and its importance for future climate change, the ice sheet's response to these dramatic changes in the past is of great interest. However, even though much effort has gone into charting YD ice margin behaviour around Greenland in recent years, no clear-cut signal of response to the oscillation has been uncovered. Here we show evidence to suggest that three major outlets from a local ice cap at Greenland's north coast advanced and retreated synchronously during YD. The evidence comprises OSL (optically stimulated luminescence) dates from a marine transgression of the coastal valleys that preceded the advance, and exposure ages from boulders on the moraines, formed by glaciers that overrode the marine sediment. The OSL ages suggest a maximum age of 12.4 ±0.6 kaBP for the marine incursion, and 10 exposure ages on boulders from the three moraines provide an average minimum age of 12.5 ±0.7 kaBP for the moraines, implying that the moraines were formed within the interval 11.8-13.0 kaBP. Elsewhere in Greenland evidence for readvance has been recorded in two areas. Most notably, in the East Greenland fjord zone outlet glaciers over a stretch of 800 km coast advanced through the fjords. In Scoresby Sund, where the moraines form a wide belt, an extensive 14C and exposure dating programme has shown that the readvance here probably culminated before YD, while cessation of moraine formation and rapid retreat from the moraine belt did not commence until c. 11.5 kaBP, but no moraines have so far been dated to YD. Readvance is also seen in Disko Bugt, the largest ice sheet outlet in West Greenland. However, here the advance and retreat of the ice stream took place in mid YD times, and lasted only a few hundred years, while YD in

  11. Accretion of southern Alaska

    USGS Publications Warehouse

    Hillhouse, J.W.

    1987-01-01

    Paleomagnetic data from southern Alaska indicate that the Wrangellia and Peninsular terranes collided with central Alaska probably by 65 Ma ago and certainly no later than 55 Ma ago. The accretion of these terranes to the mainland was followed by the arrival of the Ghost Rocks volcanic assemblage at the southern margin of Kodiak Island. Poleward movement of these terranes can be explained by rapid motion of the Kula oceanic plate, mainly from 85 to 43 Ma ago, according to recent reconstructions derived from the hot-spot reference frame. After accretion, much of southwestern Alaska underwent a counterclockwise rotation of about 50 ?? as indicated by paleomagnetic poles from volcanic rocks of Late Cretaceous and Early Tertiary age. Compression between North America and Asia during opening of the North Atlantic (68-44 Ma ago) may account for the rotation. ?? 1987.

  12. Effects of dietary stachyose on growth performance, digestive enzyme activities and intestinal morphology of juvenile turbot ( Scophthalmus maximus L)

    NASA Astrophysics Data System (ADS)

    Hu, Haibin; Zhang, Yanjiao; Mai, Kangsen; Ai, Qinghui; Xu, Wei; Zhang, Wenbing; Li, Yanxian; Liu, Jintao

    2015-10-01

    A 12-week feeding trial was conducted to evaluate the effects of dietary stachyose on the growth performance, digestive enzymes activities and intestinal structures of juvenile turbot ( Scophthalmus maximus L). Five isonitrogenous (49.58% crude protein) and isolipidic (10.50% crude lipid) diets were formulated to contain 0 (Control), 0.625% (S-0.625), 1.25% (S-1.25), 2.5% (S-2.5) and 5% (S-5) stachyose, respectively. With the increase of stachyose level, the growth performance and feed utilization of turbot, such as the specific growth rate, final mean body weight, weight gain rate and feed efficiency, increased significantly ( P< 0.05) and then stabilized. The feed intake of fish fed S-5 was significantly higher ( P< 0.05) than that of fish in other groups. The activities of trypsin, intestinal caseinolytic, stomach and intestinal amylase were significantly influenced by stachyose ( P<0.05). The highest values of trypsin and intestinal caseinolytic activities were observed in group S-1.25, while the highest activity of stomach amylase and the lowest activity of intestine amylase were observed in group S-5. No lesion or damage was found on the distal intestine structures of fish from all treatments, while the height of simple folds in the distal intestine was significantly increased ( P< 0.05) when 1.25% or 2.5% stachyose was added in the diets. These results indicated that moderate level of stachyose (1.25%) improves the growth performance, feed utilization, digestive enzyme activities and the distal intestine structures of juvenile turbot.

  13. Effectiveness of probiotic Phaeobacter bacteria grown in biofilters against Vibrio anguillarum infections in the rearing of Turbot (Psetta maxima) larvae.

    PubMed

    Prol-García, María J; Pintado, José

    2013-12-01

    The rearing environment of first-feeding turbot larvae, usually with high larvae densities and organic matter concentrations, may promote the growth of opportunistic pathogenic Vibrionaceae bacteria, compromising the survival of the larvae. The aim of this study was to assess the effectiveness of the biofilm-forming probiotic Phaeobacter 27-4 strain grown on a ceramic biofilter (probiofilter) in preventing Vibrio anguillarum infections in turbot larvae. In seawater with added microalgae and maintained under turbot larvae rearing conditions, the probiofilter reduced the total Vibrionaceae count and the concentration of V. anguillarum, which was undetectable after 144 h by real-time PCR. The probiofilter also improved the survival of larvae challenged with V. anguillarum, showing an accumulated mortality similar to that of uninfected larvae (35-40 %) and significantly (p < 0.05) lower than that of infected larvae with no probiofilter (76 %) due to a decrease in the pathogen concentration and in total Vibrionaceae. Furthermore, the probiofilter improved seawater quality by decreasing turbidity. Phaeobacter 27-4 released from the probiofilters was able to survive in the seawater for at least 11 days. The bacterial diversity in the larvae, analysed by denaturing gradient gel electrophoresis, was low, as in the live prey (rotifers), and remained unchanged in the presence of V. anguillarum or the probiofilter; however, the probiofilter reduced the bacterial carrying capacity of the seawater in the tanks. Phaeobacter-grown biofilters can constantly inoculate probiotics into rearing tanks and are therefore potentially useful for bacterial control in both open and recirculating industrial units.

  14. Cloning and expression analysis of a Toll-like receptor 22 (tlr22) gene from turbot, Scophthalmus maximus.

    PubMed

    Hu, Guo-Bin; Zhang, Shou-Feng; Yang, Xi; Liu, Da-Hai; Liu, Qiu-Ming; Zhang, Shi-Cui

    2015-06-01

    Toll-like receptor 22 (TLR22) exists exclusively in aquatic animals and recognizes double stranded RNA (dsRNA). In the present study, a tlr22 gene and its 5'-flanking sequence were cloned from turbot, Scophthalmus maximus, its immune responsive expression was subsequently studied in vivo. The turbot (sm)tlr22 gene spans over 5.6 kb with a structure of 4 exon-3 intron and encodes 962 amino acids. The deduced protein shows the highest sequence identity (76.7%) to Japanese flounder Tlr22 and possesses a signal peptide sequence, a leucine-rich repeat (LRR) domain composed of 27 LRR motifs, a transmembrane region and a Toll/interleukin-1 receptor (TIR) domain. Phylogenetic analysis grouped it with other teleost Tlr22s. The interferon-stimulated response element (ISRE) and signal transducer and activator of transcription (STAT) binding site important for the basal transcriptional activity of TLR3 were predicted in the 5'-flanking sequence of smtlr22 gene. Quantitative real-time PCR (qPCR) analysis demonstrated the constitutive expression of smtlr22 mRNA in all examined tissues with higher levels in the head kidney, kidney and spleen. Further, smtlr22 expression was significantly up-regulated following challenge with polyinosinic: polycytidylic acid (poly I:C), lipopolysaccharide (LPS) or turbot reddish body iridovirus (TRBIV) in the gills, head kidney, spleen and muscle, with maximum increases ranging from 2.56 to 6.24 fold upon different immunostimulants and organs. These findings suggest a possible role of Smtlr22 in the immune responses to the infections of a broad range of pathogens that include DNA and RNA viruses and Gram-negative bacteria. PMID:25770871

  15. Effects of dietary carbohydrate-to-lipid ratio on the growth performance and feed utilization of juvenile turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Miao, Shuyan; Nie, Qin; Miao, Huijun; Zhang, Wenbing; Mai, Kangsen

    2016-08-01

    A 9-week feeding trial was conducted to investigate the effects of dietary carbohydrate to lipid ratio (CHO:LIP) on the growth performance and feed utilization of juvenile turbot Scophthalmus maximus (initial body weight 8.75 g ± 0.04 g). Four isonitrogenous and isoenergetic low protein level (39%) diets were formulated with increasing ratios of dietary carbohydrate to lipid (2:18, 6:18, 18:12 and 28:6). A high protein level (50%) diet with the 2:12 ratio of carbohydrate to lipid was used as the control. Results showed that the survival rate, contents of moisture, crude protein and ash in muscle were not significantly affected by dietary treatments. With the dietary CHO:LIP ratio increased from 2:18 to 18:12, weight gain rate significantly increased ( P < 0.05). Higher dietary CHO:LIP ratio (28:6) resulted in the significantly decreased weight gain rate ( P < 0.05). Meanwhile, this treatment also resulted in the highest daily feed intake and liver glycogen content, as well as the lowest feed efficiency ( P < 0.05). Muscle glycogen content in fish fed the diet with 2:12 or 2:18 CHO:LIP ratio was significantly lower than those fed with the other three diets ( P < 0.05). The present results confirmed that the juvenile turbot can utilize carbohydrate. Furthermore, the appropriate ratio of dietary carbohydrate to lipid was important to the growth and feed utilization of turbot. The proper CHO:LIP ratio based on the growth performance in the present study was determined to be 18:12 when the dietary protein level was 39%.

  16. Paleoclimate. Synchronization of North Pacific and Greenland climates preceded abrupt deglacial warming.

    PubMed

    Praetorius, Summer K; Mix, Alan C

    2014-07-25

    Some proposed mechanisms for transmission of major climate change events between the North Pacific and North Atlantic predict opposing patterns of variations; others suggest synchronization. Resolving this conflict has implications for regulation of poleward heat transport and global climate change. New multidecadal-resolution foraminiferal oxygen isotope records from the Gulf of Alaska (GOA) reveal sudden shifts between intervals of synchroneity and asynchroneity with the North Greenland Ice Core Project (NGRIP) δ(18)O record over the past 18,000 years. Synchronization of these regions occurred 15,500 to 11,000 years ago, just prior to and throughout the most abrupt climate transitions of the last 20,000 years, suggesting that dynamic coupling of North Pacific and North Atlantic climates may lead to critical transitions in Earth's climate system. PMID:25061208

  17. USGS Alaska State Mosaic

    USGS Publications Warehouse

    ,

    2008-01-01

    The Alaska State Mosaic consists of portions of scenes from the Multi-Resolution Land Characteristics 2001 (MRLC 2001) collection. The 172 selected scenes have been geometrically and radiometrically aligned to produce a seamless, relatively cloud-free image of the State. The scenes were acquired between July 1999 and September 2002, resampled to 120-meter pixels, and cropped to the State boundary. They were reprojected into a standard Alaska Albers projection with the U.S. National Elevation Dataset (NED) used to correct for relief.

  18. ICESat Observations of Southern Alaska Glaciers

    NASA Technical Reports Server (NTRS)

    Sauber, Jeanne; Molnia, Bruce F.; Mitchell, Darius

    2003-01-01

    In late February and March, 2003, the Ice, Cloud, and land Elevation Satellite (ICESat) measured ice and land elevations along profiles across southern Alaska. During this initial data acquisition stage ICESat observations were made on 8-day repeat tracks to enable calibration and validation of the ICESat data products. Each profile consists of a series of single point values derived from centroid elevations of an $\\approx$70 m diameter laser footprint. The points are s4pakated by $\\approx$172 m along track. Data siets of 8-day observations (an ascending and descending ground track) crossed the Bering and Malaspina Glacier. Following its 1993--1995 surge; the Bering Glacier has undergone major terminus retreat as well as ike thinning in the abtation zone. During the later part of the 20th century, parts of the Malaspina thinned by about 1 m/yr. The multiple observation profiles across the Bering and Malaspina piedmont lobes obtained in February/March are being geolocated on Landsat images and the elevation profiles will be used for a number o scientific objectives. Based on our simulations of ICESat performance over the varied ice surface of the Jakobshavn Glacier of GReenland, 2003, we expect to measure annual, and possibly seasonal, ice elevation changes on the large Alaskan glaciers. Using elevation data obtained from a second laser, we plan to estimate ice elevation changes on the Bering Glacier between March and October 2003.

  19. Pharmacokinetics and tissue behavior of enrofloxacin and its metabolite ciprofloxacin in turbot Scophthalmus maximus at two water temperatures

    NASA Astrophysics Data System (ADS)

    Liang, Junping; Li, Jian; Zhao, Fazhen; Liu, Ping; Chang, Zhiqiang

    2012-07-01

    Turbot Scophthalmus maximus, an important aquaculture species in China, currently suffers from epizootic diseases because of high density aquaculture. Enrofloxacin has been used to treat various systemic bacterial fish infections. However, studies concerning the pharmacokinetics of enrofloxacin in turbot are limited. In this study, the pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin, were investigated in the turbot following intravenous and oral administration at 10 mg enrofloxacin/kg body weight, at 16°C and 10°C water temperatures. The concentrations of enrofloxacin and ciprofloxacin in the main tissues (plasma, muscle, liver and kidney) were detected by HPLC. The results show that the plasma concentration-time data for enrofloxacin were best described as a two-compartment open model after intravenous and oral administration. Three pharmacokinetic equations were established between the concentrations and temperatures. The kinetic profile of enrofloxacin was temperature dependent. The absorption half-life of enrofloxacin was 1.99 h and 2.17 h after oral administration, whereas the elimination half-life of the drug was 98.63 h and 136.59 h at 16°C and 10°C, respectively. The peak concentration of enrofloxacin in plasma and tissues was higher at 16°C than that at 10°C, and the peak plasma concentration time in the liver was the shortest at both temperatures among those of other tissues. The plasma C max /MIC ratio varied between 11.08 and 5 540.00 at 16°C; and between 7.92 and 3 960.00 at 10°C. The AUC/MIC ratio was 467.82-280 690.00 at 16°C, and 359.48-215 690.00 at 10°C. These ratios indicate that it is possible to obtain therapeutic efficacy. Very low levels of ciprofloxacin were detected. The AUC ratios of ciprofloxacin and enrofloxacin in plasma suggest that plasma ciprofloxacin might play a minor role in enrofloxacin treatment for turbot.

  20. Ellesmere Island (Canada) and Northern Greenland

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In late July, our planet.s northernmost land masses appear to finally be responding to the warmth of Northern Hemisphere summer. Ellesmere Island, Canada, (top left) and northern Greenland (right) have decided kick off their snowy winter garments in this true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from July 3, 200. Bare brown soils are exposed along the coasts of the still frozen (but thawing!) Arctic waters. Several large, permanent ice caps and glaciers will remain on Ellesmere Island year-round, and Greenland does little more than remove her mittens, but thinning, blue ice is showing up in the many fjords and inlets in the rocky coastlines, showing that temperatures are on the rise. The Nares Strait, which separates the two land masses, still has a way to go before a passage opens up between Baffin Bay to the south and the Artic Ocean to the north. Although Ellesmere Island appears to be 'higher' or farther north than Greenland, that is simply a result of the way the high-latitude scene was projected into an image. To better picture the terrain, imagine that you took a printed copy of the rectangular image and rolled it into a cylinder along its northeast-southwest axis. If you held that cylinder straight up in front of you, you would find that Peary Land, Greenland (right of center), is actually the more northern terrain. In fact Peary Land is the northernmost point on land on the Earth.

  1. Characterization of household waste in Greenland

    SciTech Connect

    Eisted, Rasmus; Christensen, Thomas H.

    2011-07-15

    The composition of household waste in Greenland was investigated for the first time. About 2 tonnes of household waste was sampled as every 7th bag collected during 1 week along the scheduled collection routes in Sisimiut, the second largest town in Greenland with about 5400 inhabitants. The collection bags were sorted manually into 10 material fractions. The household waste composition consisted primarily of biowaste (43%) and the combustible fraction (30%), including anything combustible that did not belong to other clean fractions as paper, cardboard and plastic. Paper (8%) (dominated by magazine type paper) and glass (7%) were other important material fractions of the household waste. The remaining approximately 10% constituted of steel (1.5%), aluminum (0.5%), plastic (2.4%), wood (1.0%), non-combustible waste (1.8%) and household hazardous waste (1.2%). The high content of biowaste and the low content of paper make Greenlandic waste much different from Danish household waste. The moisture content, calorific value and chemical composition (55 elements, of which 22 were below detection limits) were determined for each material fraction. These characteristics were similar to what has been found for material fractions in Danish household waste. The chemical composition and the calorific value of the plastic fraction revealed that this fraction was not clean but contained a lot of biowaste. The established waste composition is useful in assessing alternative waste management schemes for household waste in Greenland.

  2. The Greenland Ice Sheet Monitoring Network (GLISN)

    NASA Astrophysics Data System (ADS)

    Anderson, K. R.; Beaudoin, B. C.; Butler, R.; Clinton, J. F.; Dahl-Jensen, T.; Ekstrom, G.; Giardini, D.; Govoni, A.; Hanka, W.; Kanao, M.; Larsen, T.; Lasocki, S.; McCormack, D. A.; Mykkeltveit, S.; Nettles, M.; Agostinetti, N. P.; Stutzmann, E.; Tsuboi, S.; Voss, P.

    2010-12-01

    The GreenLand Ice Sheet monitoring Network (GLISN) is an international, broadband seismic capability for Greenland, being installed and implemented through the collaboration of Denmark, Canada, Germany, Italy, Japan, Norway, Poland, Switzerland, and USA. GLISN is a real-time sensor array of seismic stations to enhance and upgrade the performance of the sparse Greenland seismic infrastructure for detecting, locating, and characterizing glacial earthquakes and other cryo-seismic phenomena, and contributing to our understanding of Ice Sheet dynamics. Complementing data from satellites, geodesy, and other sources, and in concert with these technologies, GLISN will provide a powerful tool for detecting change, and will advance new frontiers of research in the glacial systems; the underlying geological and geophysical processes affecting the Greenland Ice Sheet; interactions between oceans, climate, and the cryosphere; and other multidisciplinary areas of interest to geoscience and climate dynamics. The glacial processes that induce seismic events (internal deformation, sliding at the base, disintegration at the calving front, drainage of supra-glacial lakes) are all integral to the overall dynamics of glaciers, and seismic observations of glaciers therefore provide a quantitative means for monitoring changes in their behavior over time. Long-term seismic monitoring of the Greenland Ice Sheet will contribute to identifying possible unsuspected mechanisms and metrics relevant to ice sheet collapse, and will provide new constraints on Ice Sheet dynamic processes and their potential roles in sea-level rise during the coming decades. GLISN will provide a new, fiducial reference network in and around Greenland for monitoring these phenomena in real-time, and for the broad seismological study of Earth and earthquakes. The 2010 summer field season saw the installation or upgrade of 9 stations in the GLISN network. Sites visited under the GLISN project include Station Nord (NOR

  3. Drivers of River Water Temperature Space-time Variability in Northeast Greenland

    NASA Astrophysics Data System (ADS)

    Hannah, D. M.; Docherty, C.; Milner, A.

    2015-12-01

    Water temperature plays an important role in stream ecosystem functioning; however, water temperature dynamics in high Arctic environments have received relatively little attention. Given that global climate is predicted to change most at high latitudes, it is vital we broaden our knowledge of space-time variability in Arctic river temperature to understand controlling processes and potential consequences of climate change. To address this gap, our research aims: (1) to characterise seasonal and diel patterns of variability over three summer and two winter seasons with contrasting hydrometeorological conditions, (2) to unravel the key drivers influencing thermal regimes and (3) to place these results in the context of other snow/ glacier-melt dominated environments. Fieldwork was undertaken in July-September 2013, 2014 and 2015 close to the Zackenberg Research Station in Northeast Greenland - an area of continuous permafrost with a mean July air temperature of 6 °C. Five streams were chosen that drain different water source contributions (glacier melt, snow melt, groundwater). Data were collected at 30 minute intervals using micro-dataloggers. Air temperature data were collected within 7km by the Greenland Survey. Weather conditions were highly variable between field campaigns, with 2013 experiencing below average, and 2014 and 2015 above average, snowfall. Summer water temperatures appear to be high in comparison to some Arctic streams in Alaska and in Svalbard. Winter snowfall extent decreases stream water temperature; and water temperature increases with atmospheric exposure time (distance from source) - illustrating the intertwined controls of water and heat fluxes. These Greenland streams are most strongly influenced by snowmelt, but groundwater contributions could increase with a changing climate due to increased active layer thickness, which may result in increased river temperature with implications for aquatic biodiversity and ecosystem functioning.

  4. Discharge of debris from ice at the margin of the Greenland ice sheet

    USGS Publications Warehouse

    Knight, P.G.; Waller, R.I.; Patterson, C.J.; Jones, A.P.; Robinson, Z.P.

    2002-01-01

    Sediment production at a terrestrial section of the ice-sheet margin in West Greenland is dominated by debris released through the basal ice layer. The debris flux through the basal ice at the margin is estimated to be 12-45 m3 m-1 a-1. This is three orders of magnitude higher than that previously reported for East Antarctica, an order of magnitude higher than sites reported from in Norway, Iceland and Switzerland, but an order of magnitude lower than values previously reported from tidewater glaciers in Alaska and other high-rate environments such as surging glaciers. At our site, only negligible amounts of debris are released through englacial, supraglacial or subglacial sediment transfer. Glacio-fluvial sediment production is highly localized, and long sections of the ice-sheet margin receive no sediment from glaciofluvial sources. These findings differ from those of studies at more temperate glacial settings where glaciofluvial routes are dominant and basal ice contributes only a minor percentage of the debris released at the margin. These data on debris flux through the terrestrial margin of an outlet glacier contribute to our limited knowledge of debris production from the Greenland ice sheet.

  5. Arctic cyclone water vapor isotopes support past sea ice retreat recorded in Greenland ice

    PubMed Central

    Klein, Eric S.; Cherry, J. E.; Young, J.; Noone, D.; Leffler, A. J.; Welker, J. M.

    2015-01-01

    Rapid Arctic warming is associated with important water cycle changes: sea ice loss, increasing atmospheric humidity, permafrost thaw, and water-induced ecosystem changes. Understanding these complex modern processes is critical to interpreting past hydrologic changes preserved in paleoclimate records and predicting future Arctic changes. Cyclones are a prevalent Arctic feature and water vapor isotope ratios during these events provide insights into modern hydrologic processes that help explain past changes to the Arctic water cycle. Here we present continuous measurements of water vapor isotope ratios (δ18O, δ2H, d-excess) in Arctic Alaska from a 2013 cyclone. This cyclone resulted in a sharp d-excess decrease and disproportional δ18O enrichment, indicative of a higher humidity open Arctic Ocean water vapor source. Past transitions to warmer climates inferred from Greenland ice core records also reveal sharp decreases in d-excess, hypothesized to represent reduced sea ice extent and an increase in oceanic moisture source to Greenland Ice Sheet precipitation. Thus, measurements of water vapor isotope ratios during an Arctic cyclone provide a critical processed-based explanation, and the first direct confirmation, of relationships previously assumed to govern water isotope ratios during sea ice retreat and increased input of northern ocean moisture into the Arctic water cycle. PMID:26023728

  6. TopoGreenland: crustal structure in central-eastern Greenland along a new refraction profile

    NASA Astrophysics Data System (ADS)

    Shulgin, Alexey; Thybo, Hans; Field Team TopoGreenland

    2013-04-01

    We present the seismic structure in the interior of Greenland based on the first measurements by the seismic refraction/wide angle reflection method. Previous seismic surveys have only been carried out offshore and near the coast of Greenland, where the crustal structure is affected by oceanic break-up and may not be representative of the interior of the island. Acquisition of geophysical data in onshore Greenland is logistically complicated by the presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The EW-trending profile extends 310 km inland from the approximate edge of the stable ice cap near Scoresby Sund across the center of the ice cap. The planned extension of the profile by use of OBSs and air gun shooting in Scoresbysund Fjord to the east coast of Greenland was unfortunately canceled, because navigation was prevented by ice drift. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along the profile. Explosive charge sizes were 1 ton at the ends and ca. 500 kg along the profile, loaded with about 125 kg at 35-85 m depth in individual boreholes. Two-dimensional velocity model based on tomographic inversion and forward ray tracing modeling shows a decrease of crustal thickness from 47 km below the center of Greenland in the western part to 40 km in the eastern part of the profile. Earlier studies show that crustal thickness further decreases eastward to ca. 30 km below the fjord system, but details of the changes are unknown. Relatively high lower crustal velocities (Vp 6.8 - 7.3) in the western part of the TopoGreenland profile may indicate past collision tectonics or may be related or to the passage of the Iceland mantle plume. The origin of the pronounced circum-Atlantic mountain ranges in Norway and eastern Greenland

  7. Identification of quantitative trait loci associated with resistance to viral haemorrhagic septicaemia (VHS) in turbot (Scophthalmus maximus ): a comparison between bacterium, parasite and virus diseases.

    PubMed

    Rodríguez-Ramilo, Silvia T; De La Herrán, Roberto; Ruiz-Rejón, Carmelo; Hermida, Miguel; Fernández, Carlos; Pereiro, Patricia; Figueras, Antonio; Bouza, Carmen; Toro, Miguel A; Martínez, Paulino; Fernández, Jesús

    2014-06-01

    One of the main objectives of genetic breeding programs in turbot industry is to reduce disease-related mortality. In the present study, a genome scan to detect quantitative trait loci (QTL) affecting resistance and survival to viral haemorrhagic septicaemia (VHS) was carried out. Three full-sib families with approximately 90 individuals each were genotyped and evaluated by linear regression and maximum likelihood approaches. In addition, a comparison between QTL detected for resistance and survival time to other important bacterial and parasite diseases affecting turbot (furunculosis and scuticociliatosis) was also carried out. Finally, the relationship between QTL affecting resistance/survival time to the virus and growth-related QTL was also evaluated. Several genomic regions controlling resistance and survival time to VHS were detected. Also significant associations between the evaluated traits and genotypes at particular markers were identified, explaining up to 14 % of the phenotypic variance. Several genomic regions controlling general and specific resistance to different diseases in turbot were detected. A preliminary gene mining approach identified candidate genes related to general or specific immunity. This information will be valuable to develop marker-assisted selection programs and to discover candidate genes related to disease resistance to improve turbot production.

  8. Interaction of temperature and salinity on the expression of immunity factors in different tissues of juvenile turbot Scophthalmus maximus based on response surface methodology

    NASA Astrophysics Data System (ADS)

    Huang, Zhihui; Ma, Aijun; Wang, Xin'an; Lei, Jilin; Li, Weiye; Wang, Ting; Yang, Zhi; Qu, Jiangbo

    2015-01-01

    Central Composite Design (CCD) and response surface methodology were used in the experiment to examine the combined effect of temperature (16-28°C) and salinity (18-42) on Hsp70 and IgM genes expression levels in turbot ( Scophthalmus maximus) liver and kidney. The results showed that the coefficients of determination ( R 2 =0.965 2 for liver Hsp70, 0.972 9 for kidney Hsp70, 0.921 for liver IgM and 0.962 1 for kidney IgM) and probability values ( P<0.01) were significant for the regression model. The interactive effect between temperature and salinity on liver Hsp70, kidney Hsp70 and liver IgM were not significant ( P>0.05), while the interactive effect between temperature and salinity on kidney IgM was significant ( P<0.01). The model equation could be used in practice for forecasting Hsp70 and IgM genes expression levels in the liver and kidney of juvenile turbot via applying statistical optimization of the response of interest, at which the maximum liver Hsp70, kidney Hsp70, liver IgM and kidney IgM of 1.48, 1.49, 2.48, and 1.38, respectively, were reached. The present model may be valuable in assessing the feasibility of turbot farming at different geographic locations and, furthermore, could be a useful reference for scientists studying the immunity of turbot.

  9. Alaska Glaciers and Rivers

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image on October 7, 2007, showing the Alaska Mountains of south-central Alaska already coated with snow. Purple shadows hang in the lee of the peaks, giving the snow-clad land a crumpled appearance. White gives way to brown on the right side of the image where the mountains yield to the lower-elevation Susitna River Valley. The river itself cuts a silver, winding path through deep green forests and brown wetlands and tundra. Extending from the river valley, are smaller rivers that originated in the Alaska Mountains. The source of these rivers is evident in the image. Smooth white tongues of ice extend into the river valleys, the remnants of the glaciers that carved the valleys into the land. Most of the water flowing into the Gulf of Alaska from the Susitna River comes from these mountain glaciers. Glacier melt also feeds glacier lakes, only one of which is large enough to be visible in this image. Immediately left of the Kahiltna River, the aquamarine waters of Chelatna Lake stand out starkly against the brown and white landscape.

  10. Alaska Mathematics Standards

    ERIC Educational Resources Information Center

    Alaska Department of Education & Early Development, 2012

    2012-01-01

    High academic standards are an important first step in ensuring that all Alaska's students have the tools they need for success. These standards reflect the collaborative work of Alaskan educators and national experts from the nonprofit National Center for the Improvement of Educational Assessment. Further, they are informed by public…

  11. Suicide in Northwest Alaska.

    ERIC Educational Resources Information Center

    Travis, Robert

    1983-01-01

    Between 1975 and 1979 the Alaskan Native suicide rate (90.9 per 100,000) in Northwest Alaska was more than seven times the national average. Alienation, loss of family, low income, alcohol abuse, high unemployment, and more education were factors related to suicidal behavior. Average age for suicidal behavior was 22.5. (Author/MH)

  12. Alaska's Young Entrepreneurs.

    ERIC Educational Resources Information Center

    Knapp, Marilyn R.

    1989-01-01

    Describes Edgecumbe Enterprises, a four-year-old fish exporting venture run by Mt. Edgecumbe High School in Sitka, Alaska, and the students' meeting with business leaders in Tokyo, Japan. The young entrepreneurs spent two weeks studying the Japanese marketing structure. (JOW)

  13. Seismology Outreach in Alaska

    NASA Astrophysics Data System (ADS)

    Gardine, L.; Tape, C.; West, M. E.

    2014-12-01

    Despite residing in a state with 75% of North American earthquakes and three of the top 15 ever recorded, most Alaskans have limited knowledge about the science of earthquakes. To many, earthquakes are just part of everyday life, and to others, they are barely noticed until a large event happens, and often ignored even then. Alaskans are rugged, resilient people with both strong independence and tight community bonds. Rural villages in Alaska, most of which are inaccessible by road, are underrepresented in outreach efforts. Their remote locations and difficulty of access make outreach fiscally challenging. Teacher retention and small student bodies limit exposure to science and hinder student success in college. The arrival of EarthScope's Transportable Array, the 50th anniversary of the Great Alaska Earthquake, targeted projects with large outreach components, and increased community interest in earthquake knowledge have provided opportunities to spread information across Alaska. We have found that performing hands-on demonstrations, identifying seismological relevance toward career opportunities in Alaska (such as natural resource exploration), and engaging residents through place-based experience have increased the public's interest and awareness of our active home.

  14. Current Ethnomusicology in Alaska.

    ERIC Educational Resources Information Center

    Johnston, Thomas F.

    The systematic study of Eskimo, Indian, and Aleut musical sound and behavior in Alaska, though conceded to be an important part of white efforts to foster understanding between different cultural groups and to maintain the native cultural heritage, has received little attention from Alaskan educators. Most existing ethnomusical studies lack one or…

  15. Alaska's Cold Desert.

    ERIC Educational Resources Information Center

    Brune, Jeff; And Others

    1996-01-01

    Explores the unique features of Alaska's Arctic ecosystem, with a focus on the special adaptations of plants and animals that enable them to survive in a stressful climate. Reviews the challenges facing public and private land managers who seek to conserve this ecosystem while accommodating growing demands for development. Includes classroom…

  16. Venetie, Alaska energy assessment.

    SciTech Connect

    Jensen, Richard Pearson; Baca, Michael J.; Schenkman, Benjamin L.; Brainard, James Robert

    2013-07-01

    This report summarizes the Energy Assessment performed for Venetie, Alaska using the principals of an Energy Surety Microgrid (ESM) The report covers a brief overview of the principals of ESM, a site characterization of Venetie, a review of the consequence modeling, some preliminary recommendations, and a basic cost analysis.

  17. A combined strategy involving Sanger and 454 pyrosequencing increases genomic resources to aid in the management of reproduction, disease control and genetic selection in the turbot (Scophthalmus maximus)

    PubMed Central

    2013-01-01

    Background Genomic resources for plant and animal species that are under exploitation primarily for human consumption are increasingly important, among other things, for understanding physiological processes and for establishing adequate genetic selection programs. Current available techniques for high-throughput sequencing have been implemented in a number of species, including fish, to obtain a proper description of the transcriptome. The objective of this study was to generate a comprehensive transcriptomic database in turbot, a highly priced farmed fish species in Europe, with potential expansion to other areas of the world, for which there are unsolved production bottlenecks, to understand better reproductive- and immune-related functions. This information is essential to implement marker assisted selection programs useful for the turbot industry. Results Expressed sequence tags were generated by Sanger sequencing of cDNA libraries from different immune-related tissues after several parasitic challenges. The resulting database (“Turbot 2 database”) was enlarged with sequences generated from a 454 sequencing run of brain-hypophysis-gonadal axis-derived RNA obtained from turbot at different development stages. The assembly of Sanger and 454 sequences generated 52,427 consensus sequences (“Turbot 3 database”), of which 23,661 were successfully annotated. A total of 1,410 sequences were confirmed to be related to reproduction and key genes involved in sex differentiation and maturation were identified for the first time in turbot (AR, AMH, SRY-related genes, CYP19A, ZPGs, STAR FSHR, etc.). Similarly, 2,241 sequences were related to the immune system and several novel key immune genes were identified (BCL, TRAF, NCK, CD28 and TOLLIP, among others). The number of genes of many relevant reproduction- and immune-related pathways present in the database was 50–90% of the total gene count of each pathway. In addition, 1,237 microsatellites and 7,362 single

  18. High-density genetic linkage mapping in turbot (Scophthalmus maximus L.) based on SNP markers and major sex- and growth-related regions detection.

    PubMed

    Wang, Weiji; Hu, Yulong; Ma, Yu; Xu, Liyong; Guan, Jiantao; Kong, Jie

    2015-01-01

    This paper describes the development of a high density consensus genetic linkage map of a turbot (Scophthalmus maximus L.) family composed of 149 mapping individuals using Single Nucleotide Polymorphisms (SNP) developed using the restriction-site associated DNA (RAD) sequencing technique with the restriction enzyme, PstI. A total of 6,647 SNPs were assigned to 22 linkage groups, which is equal to the number of chromosome pairs in turbot. For the first time, the average marker interval reached 0.3958 cM, which is equal to approximately 0.1203 Mb of the turbot genome. The observed 99.34% genome coverage indicates that the linkage map was genome-wide. A total of 220 Quantitative Traits Locus (QTLs) associated with two body length traits, two body weight traits in different growth periods and sex determination were detected with an LOD > 5.0 in 12 linkage groups (LGs), which explained the corresponding phenotypic variance (R2), ranging from 14.4-100%. Among them, 175 overlapped with linked SNPs, and the remaining 45 were located in regions between contiguous SNPs. According to the QTLs related to growth trait distribution and the changing of LGs during different growth periods, the growth traits are likely controlled by multi-SNPs distributed on several LGs; the effect of these SNPs changed during different growth periods. Most sex-related QTLs were detected at LG 21 with a linkage span of 70.882 cM. Additionally, a small number of QTLs with high feasibility and a narrow R2 distribution were also observed on LG7 and LG14, suggesting that multi LGs or chromosomes might be involved in sex determination. High homology was recorded between LG21 in Cynoglossus semilaevis and turbot. This high-saturated turbot RAD-Seq linkage map is undoubtedly a promising platform for marker assisted selection (MAS) and flatfish genomics research.

  19. Molecular cloning and expression studies of the adapter molecule myeloid differentiation factor 88 (MyD88) in turbot (Scophthalmus maximus).

    PubMed

    Lin, Jing-Yun; Hu, Guo-Bin; Yu, Chang-Hong; Li, Song; Liu, Qiu-Ming; Zhang, Shi-Cui

    2015-10-01

    Myeloid differentiation factor 88 (MyD88) is an adapter protein involved in the interleukin-1 receptor (IL-1R) and Toll-like receptor (TLR)-mediated activation of nuclear factor-kappaB (NF-κB). In this study, a full length cDNA of MyD88 was cloned from turbot, Scophthalmus maximus. It is 1619 bp in length and contains an 858-bp open reading frame that encodes a peptide of 285 amino acid residues. The putative turbot (Sm)MyD88 protein possesses a N-terminal death domain and a C-terminal Toll/IL-1 receptor (TIR) domain known to be important for the functions of MyD88 in mammals. Phylogenetic analysis grouped SmMyD88 with other fish MyD88s. SmMyD88 mRNA was ubiquitously expressed in all examined tissues of healthy turbots, with higher levels observed in immune-relevant organs. To explore the role of SmMyD88, its gene expression profile in response to stimulation of lipopolysaccharide (LPS), CpG oligodeoxynucleotide (CpG-ODN) or turbot reddish body iridovirus (TRBIV) was studied in the head kidney, spleen, gills and muscle over a 7-day time course. The results showed an up-regulation of SmMyD88 transcript levels by the three immunostimulants in all four examined tissues, with the induction by CpG-ODN strongest and initiated earliest and inducibility in the muscle very weak. Additionally, TRBIV challenge resulted in a quite high level of SmMyD88 expression in the spleen, whereas the two synthetic immunostimulants induced the higher levels in the head kidney. These data provide insights into the roles of SmMyD88 in the TLR/IL-1R signaling pathway of the innate immune system in turbot. PMID:26025195

  20. Comparative study of ranavirus isolates from cod (Gadus morhua) and turbot (Psetta maxima) with reference to other ranaviruses.

    PubMed

    Ariel, Ellen; Holopainen, Riikka; Olesen, Niels Jørgen; Tapiovaara, Hannele

    2010-08-01

    Two iridovirus isolates recovered from cod (Gadus morhua) and turbot (Psetta maxima) in Denmark were examined in parallel with a panel of other ranaviruses including frog virus 3 (FV3), the reference strain for the genus Ranavirus. The isolates were assessed according to their reactivity in immunofluoresent antibody tests (IFAT) using both homologous and heterologous antisera and their amplification in PCR using primers targeting five genomic regions. The corresponding PCR fragments were sequenced, and the sequences obtained were used in phylogenetic analysis. In addition, the pathogenicity to rainbow trout under experimental challenge conditions was investigated. The viruses were serologically and genetically closely related to highly pathogenic ranaviruses such as European catfish iridovirus (ECV), European sheatfish iridovirus (ESV) and epizootic haematopoietic necrosis virus (EHNV). The challenge trials indicate that rainbow trout fry cultured at 15 degrees C are not target species for the virus isolates in the present panel. We suggest that the two isolates belong in the genus Ranavirus and propose the name Ranavirus maxima (Rmax) for the turbot isolate.

  1. Isolation and characterization of 45 Polymorphie microsatellite loci of turbot ( Scophthalmus maximus) and cross-species amplification

    NASA Astrophysics Data System (ADS)

    Hou, Shiying; Ma, Aijun; Wang, Xin'an; Huang, Zhihui; Xue, Baogui; Yang, Zhi; Qu, Jiangbo

    2011-03-01

    Turbot ( Scophthalmus maximus) is a flatfish species commercially important for aquaculture. In this study, we generated a microsatellite-enriched genomic DNA library for Scophthalmus maximus, and then isolated and characterized 45 microsatellite loci by genotyping 30 individuals. The observed number of alleles ranged from 2 to 19 with an average of 6.24, while the effective number of alleles ranged from 1.30 to 11.11 with an average of 3.66. The expected heterozygosities varied from 0.235 to 0.925 4 and Polymorphie information content ranged from 0.2044 to 0.903 3, with an average of 0.622. Twelve loci deviated significantly from Hardy-Weinberg equilibrium, and no significant linkage disequilibrium was observed between any pair of loci after Bonferroni correction. In cross-species amplification, five flatfish species ( Paralichthys lethostigma, Verasper moseri, platichthys stellatus, Hippoglossoides dubius and Cynoglossus semilaevis) showed at least one Polymorphie locus. These Polymorphie microsatellite loci should prove useful for Population analysis of turbot and other related species.

  2. Aliphatic hydrocarbon levels in turbot and salmon farmed close to the site of the Aegean Sea oil spill

    SciTech Connect

    Alvarez Pineiro, M.E.; Gonzalez-Barros, S.T.C.; Lozano, J.S.

    1996-12-31

    After the Andros Patria oil spill, the most serious oil tanker accident to occur off the coast of Galicia (N.W. Spain) was the running aground and subsequent conflagration of the Aegean Sea supertanker outside the northern Spanish port of La Coruna (December 3rd 1992). Approximately 60,000 tonnes of Brent oil were spilled into the Atlantic Ocean in the cited coastal region. Subsequently, an impropitious combination of a high tide and a change in wind direction caused the resulting slick to rapidly spread into the port. Measures aimed at cleaning up affected areas and evacuating the ca. 11,215 tonnes of oil remaining in the supertanker were immediately implemented. However, within just a few days the resulting contamination had killed some 15000 turbot juveniles and larvae, which are cultivated in fish farms close to the accident site. The environmental impact of major oil spillages has been widely studied. Several scientists have suggested that, in terms of the negative effects on the seawater quality and productive capacity of the affected maritime regions, the magnitudes of the Aegean Sea and Amoco Cadiz accidents are comparable. This paper reports variations over time of aliphatic hydrocarbon levels in turbot and Atlantic salmon sampled from fish farms close to the site of the Aegean Sea oil spill. 6 refs., 2 figs., 1 tab.

  3. Low temperature stress on the hematological parameters and HSP gene expression in the turbot Scophthalmus maximus

    NASA Astrophysics Data System (ADS)

    Ji, Liqin; Jiang, Keyong; Liu, Mei; Wang, Baojie; Han, Longjiang; Zhang, Mingming; Wang, Lei

    2016-05-01

    To study the effect of low temperature stress on hematological parameters and HSP gene expression in the turbot ( Scophthalmus maximus), water temperature was lowered rapidly from 18 to 1°C. During the cooling process, three individuals were removed from culture tanks at 18, 13, 8, 5, 3, and 1°C. Blood samples and tissues were taken from each individual, hematological indices and HSP gene expression in tissues were measured. The red blood cell count, white blood cell count, and hemoglobin concentration decreased significantly ( P < 0.05) as temperature decreased. Enzyme activities of plasma alanine transaminase and creatine kinase increased as temperature decreased, whereas aspartic transaminase and γ-glutamyl transpeptidase activities displayed no obvious changes above 1°C and lactate dehydrogenase activity increased first and then decreased. Blood urea nitrogen and uric acid levels were highest at 8°C, and creatinine concentration was highest at 3°C. The concentrations of plasma cortisol, cholesterol, and triglyceride all increased significantly ( P < 0.05) as temperature decreased. The serum glucose concentration increased first and then decreased to the initial level. The HSP70 mRNA expression showed various patterns in different tissues, whereas HSP90 mRNA expression showed the same tendency in all tissues. Overall, these results indicate that temperature decreases in the range of 8 to 5°C may induce a stress response in S. maximus and that temperature should be kept above 8°C in the aquaculture setting to avoid damage to the fish.

  4. Fecundity regulation by atresia in turbot Scophthalmus maximus in the Baltic Sea.

    PubMed

    Nissling, A; Thorsen, A; da Silva, F F G

    2016-04-01

    Down-regulation of fecundity through oocyte resorption was assessed in Baltic Sea turbot Scophthalmus maximus at three locations in the period from late vitellogenesis in April to spawning during June to July. The mean ± s.d. total length of the sampled fish was 32.7 ± 3.1 cm and mean ± s.d. age was 6.2 ± 1.5 years. Measurements of atresia were performed using the 'profile method' with the intensity of atresia adjusted according to the 'dissector method' (10.6% adjustment; coefficient of determination was 0.675 between methods). Both prevalence (portion of fish with atresia) and intensity (calculated as the average proportion of atretic cells in fish displaying atresia) of atresia were low in prespawning fish, but high from onset of spawning throughout the spawning period. Atretic oocytes categorized as in early alpha and in late alpha state occurred irrespective of maturity stage from late prespawning individuals up to late spawning fish, showing that oocytes may become atretic throughout the spawning period. Observed prevalence of atresia throughout the spawning period was almost 40% with an intensity of c. 20%. This indicates extensive down-regulation, i.e. considerably lower realized (number of eggs spawned) v. potential fecundity (number of developing oocytes), suggesting significant variability in reproductive potential. The extent of fecundity regulation in relation to fish condition (Fulton's condition factor) is discussed, suggesting an association between levels of atresia and fish condition. PMID:26928526

  5. Effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus).

    PubMed

    Jia, Rui; Han, Cen; Lei, Ji-Lin; Liu, Bao-Liang; Huang, Bin; Huo, Huan-Huan; Yin, Shu-Ting

    2015-12-01

    Nitrite (NO2(-)) is commonly present as contaminant in aquatic environment and toxic to aquatic organisms. In the present study, we investigated the effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus). Fish were exposed to various concentrations of nitrite (0, 0.02, 0.08, 0.4 and 0.8mM) for 96 h. Fish blood and gills were collected to assay haematological parameters, oxidative stress and expression of genes after 0, 24, 48 and 96 h of exposure. In blood, the data showed that the levels of methemoglobin (MetHb), triglyceride (TG), potassium (K(+)), cortisol, heat shock protein 70 (HSP70) and glucose significantly increased in treatments with higher concentrations of nitrite (0.4 and/or 0.8mM) after 48 and 96 h, while the levels of haemoglobin (Hb) and sodium (Na(+)) significantly decreased in these treatments. In gills, nitrite (0.4 and/or 0.8mM) apparently reduced the levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione (GSH), increased the formation of malondialdehyde (MDA), up-regulated the mRNA levels of c-jun amino-terminal kinase (JUK1), p53, caspase-3, caspase-7 and caspase-9 after 48 and 96 h of exposure. The results suggested caspase-dependent and JUK signaling pathways played important roles in nitrite-induced apoptosis in fish. Further, this study provides new insights into how nitrite affects the physiological responses and apoptosis in a marine fish. PMID:26476021

  6. Vaccine-induced modulation of gene expression in turbot peritoneal cells. A microarray approach.

    PubMed

    Fontenla, Francisco; Blanco-Abad, Verónica; Pardo, Belén G; Folgueira, Iria; Noia, Manuel; Gómez-Tato, Antonio; Martínez, Paulino; Leiro, José M; Lamas, Jesús

    2016-07-01

    We used a microarray approach to examine changes in gene expression in turbot peritoneal cells after injection of the fish with vaccines containing the ciliate parasite Philasterides dicentrarchi as antigen and one of the following adjuvants: chitosan-PVMMA microspheres, Freund́s complete adjuvant, aluminium hydroxide gel or Matrix-Q (Isconova, Sweden). We identified 374 genes that were differentially expressed in all groups of fish. Forty-two genes related to tight junctions and focal adhesions and/or actin cytoskeleton were differentially expressed in free peritoneal cells. The profound changes in gene expression related to cell adherence and cytoskeleton may be associated with cell migration and also with the formation of cell-vaccine masses and their attachment to the peritoneal wall. Thirty-five genes related to apoptosis were differentially expressed. Although most of the proteins coded by these genes have a proapoptotic effect, others are antiapoptotic, indicating that both types of signals occur in peritoneal leukocytes of vaccinated fish. Interestingly, many of the genes related to lymphocytes and lymphocyte activity were downregulated in the groups injected with vaccine. We also observed decreased expression of genes related to antigen presentation, suggesting that macrophages (which were abundant in the peritoneal cavity after vaccination) did not express these during the early inflammatory response in the peritoneal cavity. Finally, several genes that participate in the inflammatory response were differentially expressed, and most participated in resolution of inflammation, indicating that an M2 macrophage response is generated in the peritoneal cavity of fish one day post vaccination. PMID:27318565

  7. Vaccine-induced modulation of gene expression in turbot peritoneal cells. A microarray approach.

    PubMed

    Fontenla, Francisco; Blanco-Abad, Verónica; Pardo, Belén G; Folgueira, Iria; Noia, Manuel; Gómez-Tato, Antonio; Martínez, Paulino; Leiro, José M; Lamas, Jesús

    2016-07-01

    We used a microarray approach to examine changes in gene expression in turbot peritoneal cells after injection of the fish with vaccines containing the ciliate parasite Philasterides dicentrarchi as antigen and one of the following adjuvants: chitosan-PVMMA microspheres, Freund́s complete adjuvant, aluminium hydroxide gel or Matrix-Q (Isconova, Sweden). We identified 374 genes that were differentially expressed in all groups of fish. Forty-two genes related to tight junctions and focal adhesions and/or actin cytoskeleton were differentially expressed in free peritoneal cells. The profound changes in gene expression related to cell adherence and cytoskeleton may be associated with cell migration and also with the formation of cell-vaccine masses and their attachment to the peritoneal wall. Thirty-five genes related to apoptosis were differentially expressed. Although most of the proteins coded by these genes have a proapoptotic effect, others are antiapoptotic, indicating that both types of signals occur in peritoneal leukocytes of vaccinated fish. Interestingly, many of the genes related to lymphocytes and lymphocyte activity were downregulated in the groups injected with vaccine. We also observed decreased expression of genes related to antigen presentation, suggesting that macrophages (which were abundant in the peritoneal cavity after vaccination) did not express these during the early inflammatory response in the peritoneal cavity. Finally, several genes that participate in the inflammatory response were differentially expressed, and most participated in resolution of inflammation, indicating that an M2 macrophage response is generated in the peritoneal cavity of fish one day post vaccination.

  8. Inflammatory responses and side effects generated by several adjuvant-containing vaccines in turbot.

    PubMed

    Noia, M; Domínguez, B; Leiro, J; Blanco-Méndez, J; Luzardo-Álvarez, A; Lamas, J

    2014-05-01

    Several of the adjuvants used in fish vaccines cause adhesions in internal organs when they are injected intraperitoneally. We describe the damage caused by vaccines containing different adjuvants in the turbot Scophthalmus maximus and show that internal adhesions can be greatly reduced by injecting the fish in a specific way. Injection of fish with the needle directed towards the anterior part of the peritoneal cavity induced formation of a single cell-vaccine mass (CVM) that became attached to the parietal peritoneum. However, injection of the fish with the needle pointing in the opposite direction generated many small CVM that became attached to the visceral and parietal peritoneum and in some cases caused internal adhesions. We describe the structural and cellular changes in the adjuvant-induced CVMs. The CVMs mainly comprised neutrophils and macrophages, although most of the former underwent apoptosis, which was particularly evident from day 3 post-injection. The apoptotic cells were phagocytosed by macrophages, which were the dominant cell type from the first days onwards. All of the vaccines induced angiogenesis in the area of contact between the CVM and the mesothelium. Vaccines containing oil-based adjuvants or microspheres induced the formation of granulomas in the CVM; however, no granulomas were observed in the CVM induced by vaccines containing aluminium hydroxide or Matrix-Q(®) as adjuvants. All of the vaccines induced strong migration of cells to the peritoneal cavity. Although some of these cells remained unattached in the peritoneal cavity, most of them formed part of the CVM. We also observed migration of the cells from the peritoneal cavity to lymphoid organs, indicating bidirectional traffic of cells between the inflamed areas and these organs.

  9. Modern solar maximum forced late twentieth century Greenland cooling

    NASA Astrophysics Data System (ADS)

    Kobashi, T.; Box, J. E.; Vinther, B. M.; Goto-Azuma, K.; Blunier, T.; White, J. W. C.; Nakaegawa, T.; Andresen, C. S.

    2015-07-01

    The abrupt Northern Hemispheric warming at the end of the twentieth century has been attributed to an enhanced greenhouse effect. Yet Greenland and surrounding subpolar North Atlantic remained anomalously cold in 1970s to early 1990s. Here we reconstructed robust Greenland temperature records (North Greenland Ice Core Project and Greenland Ice Sheet Project 2) over the past 2100 years using argon and nitrogen isotopes in air trapped within ice cores and show that this cold anomaly was part of a recursive pattern of antiphase Greenland temperature responses to solar variability with a possible multidecadal lag. We hypothesize that high solar activity during the modern solar maximum (approximately 1950s-1980s) resulted in a cooling over Greenland and surrounding subpolar North Atlantic through the slowdown of Atlantic Meridional Overturning Circulation with atmospheric feedback processes.

  10. Asthma and American Indians/Alaska Natives

    MedlinePlus

    ... Minority Population Profiles > American Indian/Alaska Native > Asthma Asthma and American Indians/Alaska Natives In 2014, 218, ... Native American adults reported that they currently have asthma. American Indian/Alaska Native children are 30% more ...

  11. Recent Changes in Arctic Glaciers, Ice Caps, and the Greenland Ice Sheet: Cold Facts About Warm Ice

    NASA Astrophysics Data System (ADS)

    Abdalati, W.

    2005-12-01

    One of the major manifestations of Arctic change can be observed in the state of balance of Arctic glaciers and ice caps and the Greenland ice sheet. These ice masses are estimated to contain nearly 3 million cubic kilometers of ice, which is more than six times greater than all the water stored in the Earth's lakes, rivers, and snow combined and is the equivalent of over 7 meters of sea level. Most of these ice masses have been shrinking in recent in years, but their mass balance is highly variable on a wide range of spatial and temporal scales. On the Greenland ice sheet most of the coastal regions have thinned substantially as melt has increased and some of its outlet glaciers have accelerated. Near the equilibrium line in West Greenland, we have seen evidence of summer acceleration that is linked to surface meltwater production, suggesting a relatively rapid response mechanism of the ice sheet change to a warming climate. At the same time, however, the vast interior regions of the Greenland ice sheet have shown little change or slight growth, as accumulation in these areas may have increased. Throughout much of the rest of the Arctic, many glaciers and ice caps have been shrinking in the past few decades, and in Canada and Alaska, the rate of ice loss seems to have accelerated during the late 1990s. These recent observations offer only a snapshot in time of the long-term behavior, but they are providing crucial information about the current state of ice mass balance and the mechanisms that control it in one of the most climatically sensitive regions on Earth. As we continue to learn more through a combination of remote sensing observations, in situ measurements and improved modeling capabilities, it is important that we coordinate and integrate these approaches effectively in order to predict future changes and their impact on sea level, freshwater discharge, and ocean circulation.

  12. MABEL photon-counting laser altimetry data in Alaska for ICESat-2 simulations and development

    NASA Astrophysics Data System (ADS)

    Brunt, K. M.; Markus, T.; Neumann, T.; Amundson, J. M.; Kavanaugh, J. L.; Cook, W. B.

    2014-12-01

    Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) is scheduled to launch in 2017 and will carry the Advanced Topographic Laser Altimeter System (ATLAS), which is a photon-counting laser altimeter and represents a new approach to space-borne determination of surface elevation. Given the new technology of ATLAS, an airborne instrument, the Multiple Altimeter Beam Experimental Lidar (MABEL), has been deployed to both Greenland (April 2012) and Alaska (July 2014) to provide data needed for: 1) satellite algorithm development; 2) to simulate key elements of this photon-counting sampling strategy; and 3) to assess elements of this sampling strategy that may vary seasonally. Here, we compare seasonal aspects of the two datasets, with a focus on results from the latter campaign, where in situ observations in southeastern Alaska help to assess instrument performance in summer conditions and in the presence of glacier melt ponds.

  13. Identifying potential Greenland halibut spawning areas and nursery grounds off East and South-western Greenland and its management implications

    NASA Astrophysics Data System (ADS)

    Gundersen, A. C.; Kennedy, J.; Woll, A.; Fossen, I.; Boje, J.

    2013-01-01

    Spawning and nursery grounds are poorly described for the West Nordic stock of Greenland halibut (Reinhardtius hippoglossoides) and the entire stock is assumed to originate from a common spawning ground southwest of Iceland. Greenland halibut with hydrated eggs in their ovary were caught during a gillnet survey in 1995 in Greenland waters. This suggests that the spawning areas for the West Nordic stock are not limited to the previously described area southwest of Iceland. Further this paper provides information on distribution of immature Greenland halibut in the fjords of East Greenland. The densities in Tasilaq area suggest that this area may be part of a nursery area in the West-Nordic management unit. However, the importance of this area to the stock is currently unknown. The results have potential implications for the management of the West Nordic Greenland halibut as the management seems to comprise of several stocks, or perhaps a meta-population.

  14. Building sustained partnerships in Greenland through shared science

    NASA Astrophysics Data System (ADS)

    Culler, L. E.; Albert, M. R.; Ayres, M. P.; Grenoble, L. A.; Virginia, R. A.

    2013-12-01

    Greenland is a hotspot for polar environmental change research due to rapidly changing physical and ecological conditions. Hundreds of international scientists visit the island each year to carry out research on diverse topics ranging from atmospheric chemistry to ice sheet dynamics to Arctic ecology. Despite the strong links between scientific, social, and political issues of rapid environmental change in Greenland, communication with residents of Greenland is often neglected by researchers. Reasons include language barriers, difficulties identifying pathways for communication, balancing research and outreach with limited resources, and limited social and cultural knowledge about Greenland by scientists. Dartmouth College has a legacy of work in the Polar Regions. In recent years, a National Science Foundation (NSF) Integrative Graduate Education and Research Traineeship (IGERT) in Polar Environmental Change funded training for 25 Ph.D. students in the Ecology, Earth Science, and Engineering graduate programs at Dartmouth. An overarching goal of this program is science communication between these disciplines and to diverse audiences, including communicating about rapid environmental change with students, residents, and the government of Greenland. Students and faculty in IGERT have been involved in the process of engaging with and sustaining partnerships in Greenland that support shared cultural and educational experiences. We have done this in three ways. First, a key component of our program has been hosting students from Ilisimatusarfik (the University of Greenland). Since 2009, five Greenlandic students have come to Dartmouth and formed personal connections with Dartmouth students while introducing their Greenlandic culture and language (Kalaallisut). Second, we have used our resources to extend our visits to Greenland, which has allowed time to engage with the community in several ways, including sharing our science via oral and poster presentations at Katuaq

  15. Satellite Gravity Measurements Confirm Accelerated Melting of Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Chen, J. L.; Wilson, C. R.; Tapley, B. D.

    2006-09-01

    Using time-variable gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) satellite mission, we estimate ice mass changes over Greenland during the period April 2002 to November 2005. After correcting for the effects of spatial filtering and limited resolution of GRACE data, the estimated total ice melting rate over Greenland is -239 +/- 23 cubic kilometers per year, mostly from East Greenland. This estimate agrees remarkably well with a recent assessment of -224 +/- 41 cubic kilometers per year, based on satellite radar interferometry data. GRACE estimates in southeast Greenland suggest accelerated melting since the summer of 2004, consistent with the latest remote sensing measurements.

  16. Greenland opens more offshore, land acreage to exploration

    SciTech Connect

    Not Available

    1992-01-13

    Greenland's Mineral Resources Administration (MRA) plans a series of licensing rounds off western Greenland. Meanwhile, the MRA has declared the Jameson Land basin of east central Greenland as open acreage. Greenland Geological Survey (GGU), Copenhagen, has prepared a report on the geographical conditions, logistics, exploration history, and geological development of Jameson Land. The article emphasizes source and reservoir rocks, conceptual play types with six seismic examples, and thermal history with basin modeling. It also includes two interpreted regional seismic lines, a geological and an aeromagnetic map, depth structure, and isopach maps of selected formations.

  17. Educating medical students for Alaska.

    PubMed

    Fortuine, R; Dimino, M J

    1998-01-01

    Because Alaska does not have its own medical school, it has become part of WAMI (Washington, Alaska, Montana, Idaho), an educational agreement with the University of Washington School of Medicine (UWSM). Each year, 10 Alaskans are accepted into the entering class of UWSM and spend their first year at the University of Alaska Anchorage (UAA). UWSM third- and fourth-year medical students can obtain some of their clinical experience in Alaska. To meet the needs of Alaska, students are chosen based on academic and personal records, as well as the likelihood of their returning to Alaska for practice. To this end, over the last seven years 30% of accepted students have come from rural communities and 10% are Alaska Natives. The curriculum for the first year includes several sessions dedicated to Alaska health problems, cross-cultural issues, and Alaska's unique rural health care delivery system. Students do two preceptorships--one with a private primary care physician and one with a physician at the Alaska Native Medical Center. Additionally, students have the option to spend a week at a rural site to learn about the community's health care system. An Alaska track is being developed whereby an Alaskan UWSM student can do most of the third year in state via clerkships in family medicine, obstetrics/gynecology, psychiatry, internal medicine, and pediatrics. All UWSM students at the end of their first year can elect to participate for one month in the R/UOP (Rural/Underserved Opportunities Program), which includes several Alaska sites. The overall goals of these approaches are to educate UWSM students, especially Alaskans, about the state's health needs and health care system and to encourage UWSM graduates to practice in the state.

  18. Holocene deceleration of the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    MacGregor, Joseph A.; Colgan, William T.; Fahnestock, Mark A.; Morlighem, Mathieu; Catania, Ginny A.; Paden, John D.; Gogineni, S. Prasad

    2016-02-01

    Recent peripheral thinning of the Greenland Ice Sheet is partly offset by interior thickening and is overprinted on its poorly constrained Holocene evolution. On the basis of the ice sheet’s radiostratigraphy, ice flow in its interior is slower now than the average speed over the past nine millennia. Generally higher Holocene accumulation rates relative to modern estimates can only partially explain this millennial-scale deceleration. The ice sheet’s dynamic response to the decreasing proportion of softer ice from the last glacial period and the deglacial collapse of the ice bridge across Nares Strait also contributed to this pattern. Thus, recent interior thickening of the Greenland Ice Sheet is partly an ongoing dynamic response to the last deglaciation that is large enough to affect interpretation of its mass balance from altimetry.

  19. Complex Greenland outlet glacier flow captured.

    PubMed

    Aschwanden, Andy; Fahnestock, Mark A; Truffer, Martin

    2016-01-01

    The Greenland Ice Sheet is losing mass at an accelerating rate due to increased surface melt and flow acceleration in outlet glaciers. Quantifying future dynamic contributions to sea level requires accurate portrayal of outlet glaciers in ice sheet simulations, but to date poor knowledge of subglacial topography and limited model resolution have prevented reproduction of complex spatial patterns of outlet flow. Here we combine a high-resolution ice-sheet model coupled to uniformly applied models of subglacial hydrology and basal sliding, and a new subglacial topography data set to simulate the flow of the Greenland Ice Sheet. Flow patterns of many outlet glaciers are well captured, illustrating fundamental commonalities in outlet glacier flow and highlighting the importance of efforts to map subglacial topography. Success in reproducing present day flow patterns shows the potential for prognostic modelling of ice sheets without the need for spatially varying parameters with uncertain time evolution. PMID:26830316

  20. Secret Science: Exploring Cold War Greenland

    NASA Astrophysics Data System (ADS)

    Harper, K.

    2013-12-01

    During the early Cold War - from the immediate postwar period through the 1960s - the United States military carried out extensive scientific studies and pursued technological developments in Greenland. With few exceptions, most of these were classified - sometimes because new scientific knowledge was born classified, but mostly because the reasons behind the scientific explorations were. Meteorological and climatological, ionospheric, glaciological, seismological, and geological studies were among the geophysical undertakings carried out by military and civilian scientists--some in collaboration with the Danish government, and some carried out without their knowledge. This poster will present some of the results of the Exploring Greenland Project that is coming to a conclusion at Denmark's Aarhus University.

  1. Complex Greenland outlet glacier flow captured

    PubMed Central

    Aschwanden, Andy; Fahnestock, Mark A.; Truffer, Martin

    2016-01-01

    The Greenland Ice Sheet is losing mass at an accelerating rate due to increased surface melt and flow acceleration in outlet glaciers. Quantifying future dynamic contributions to sea level requires accurate portrayal of outlet glaciers in ice sheet simulations, but to date poor knowledge of subglacial topography and limited model resolution have prevented reproduction of complex spatial patterns of outlet flow. Here we combine a high-resolution ice-sheet model coupled to uniformly applied models of subglacial hydrology and basal sliding, and a new subglacial topography data set to simulate the flow of the Greenland Ice Sheet. Flow patterns of many outlet glaciers are well captured, illustrating fundamental commonalities in outlet glacier flow and highlighting the importance of efforts to map subglacial topography. Success in reproducing present day flow patterns shows the potential for prognostic modelling of ice sheets without the need for spatially varying parameters with uncertain time evolution. PMID:26830316

  2. Holocene deceleration of the Greenland Ice Sheet.

    PubMed

    MacGregor, Joseph A; Colgan, William T; Fahnestock, Mark A; Morlighem, Mathieu; Catania, Ginny A; Paden, John D; Gogineni, S Prasad

    2016-02-01

    Recent peripheral thinning of the Greenland Ice Sheet is partly offset by interior thickening and is overprinted on its poorly constrained Holocene evolution. On the basis of the ice sheet's radiostratigraphy, ice flow in its interior is slower now than the average speed over the past nine millennia. Generally higher Holocene accumulation rates relative to modern estimates can only partially explain this millennial-scale deceleration. The ice sheet's dynamic response to the decreasing proportion of softer ice from the last glacial period and the deglacial collapse of the ice bridge across Nares Strait also contributed to this pattern. Thus, recent interior thickening of the Greenland Ice Sheet is partly an ongoing dynamic response to the last deglaciation that is large enough to affect interpretation of its mass balance from altimetry. PMID:26912699

  3. Significant Alaska minerals

    SciTech Connect

    Robinson, M.S.; Bundtzen, T.K.

    1982-01-01

    Alaska ranks in the top four states in gold production. About 30.5 million troy oz have been produced from lode and placer deposits. Until 1930, Alaska was among the top 10 states in copper production; in 1981, Kennecott Copper Company had prospects of metal worth at least $7 billion. More than 85% of the 20 million oz of silver derived have been byproducts of copper mining. Nearly all lead production has been as a byproduct of gold milling. Molybdenum is a future Alaskan product; in 1987 production is scheduled to be about 12% of world demand. Uranium deposits discovered in the Southeast are small but of high grade and easily accessible; farther exploration depends on improvement of a depressed market. Little has been done with Alaskan iron and zinc, although large deposits of the latter were discovered. Alaskan jade has a market among craftspeople. A map of the mining districts is included. 2 figures, 1 table.

  4. Seabirds in Alaska

    USGS Publications Warehouse

    Hatch, Scott A.; Piatt, John F.

    1995-01-01

    Techniques for monitoring seabird populations vary according to habitat types and the breeding behavior of individual species (Hatch and Hatch 1978, 1989; Byrd et al. 1983). An affordable monitoring program can include but a few of the 1,300 seabird colonies identified in Alaska, and since the mid-1970's, monitoring effotrts have emphasized a small selection of surface-feeding and diving species, primarily kittiwakes (Rissa spp.) and murres (Uria spp.). Little or no information on trends is available for other seabirds (Hatch 1993a). The existing monitoring program occurs largely on sites within the Alaska Maritime National Wildlife Refuge, which was established primarily for the conservation of marine birds. Data are collected by refuge staff, other state and federal agencies, private organizations, university faculty, and students.

  5. Coal resources of Alaska

    SciTech Connect

    Sanders, R.B.

    1982-01-01

    In the late 1800s, whaling ships carried Alaskan coal, and it was used to thaw ground for placer gold mining. Unfortunate and costly political maneuvers in the early 1900s delayed coal removal, but the Alaska Railroad and then World War II provided incentives for opening mines. Today, 33 million acres (about 9% of the state) is classified as prospectively valuable for coal, much of it under federal title. Although the state's geology is poorly known, potential for discovery of new fields exists. The US Geological Survey estimates are outdated, although still officially used. The total Alaska onshore coal resource is estimated to be 216 to 4216 billion tons of which 141 billion tons are identified resources; an additional 1430 billion tons are believed to lie beneath Cook Inlet. Transportation over mountain ranges and wetlands is the biggest hurdle for removal. Known coal sources and types are described and mapped. 1 figure.

  6. Geologic map of Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.; Hults, Chad P.; Mull, Charles G.; Karl, Susan M.

    2015-12-31

    This Alaska compilation is unique in that it is integrated with a rich database of information provided in the spatial datasets and standalone attribute databases. Within the spatial files every line and polygon is attributed to its original source; the references to these sources are contained in related tables, as well as in stand-alone tables. Additional attributes include typical lithology, geologic setting, and age range for the map units. Also included are tables of radiometric ages.

  7. Aniakchak Crater, Alaska Peninsula

    USGS Publications Warehouse

    Smith, Walter R.

    1925-01-01

    The discovery of a gigantic crater northwest of Aniakchak Bay (see fig. 11) closes what had been thought to be a wide gap in the extensive series of volcanoes occurring at irregular intervals for nearly 600 miles along the axial line of the Alaska Peninsula and the Aleutian Islands. In this belt there are more active and recently active volcanoes than in all the rest of North America. Exclusive of those on the west side of Cook Inlet, which, however, belong to the same group, this belt contains at least 42 active or well-preserved volcanoes and about half as many mountains suspected or reported to be volcanoes. The locations of some of these mountains and the hot springs on the Alaska Peninsula and the Aleutian Islands are shown on a map prepared by G. A. Waring. Attention has been called to these volcanoes for nearly two centuries, but a record of their activity since the discovery of Alaska is far from being complete, and an adequate description of them as a group has never been written. Owing to their recent activity or unusual scenic beauty, some of the best known of the group are Mounts Katmai, Bogoslof, and Shishaldin, but there are many other beautiful and interesting cones and craters.

  8. Rapid wastage of Alaska glaciers and their contribution to rising sea level.

    PubMed

    Arendt, Anthony A; Echelmeyer, Keith A; Harrison, William D; Lingle, Craig S; Valentine, Virginia B

    2002-07-19

    We have used airborne laser altimetry to estimate volume changes of 67 glaciers in Alaska from the mid-1950s to the mid-1990s. The average rate of thickness change of these glaciers was -0.52 m/year. Extrapolation to all glaciers in Alaska yields an estimated total annual volume change of -52 +/- 15 km3/year (water equivalent), equivalent to a rise in sea level (SLE) of 0.14 +/- 0.04 mm/year. Repeat measurements of 28 glaciers from the mid-1990s to 2000-2001 suggest an increased average rate of thinning, -1.8 m/year. This leads to an extrapolated annual volume loss from Alaska glaciers equal to -96 +/- 35 km3/year, or 0.27 +/- 0.10 mm/year SLE, during the past decade. These recent losses are nearly double the estimated annual loss from the entire Greenland Ice Sheet during the same time period and are much higher than previously published loss estimates for Alaska glaciers. They form the largest glaciological contribution to rising sea level yet measured.

  9. Towards Greenland Glaciation: Cumulative or Abrupt Transition?

    NASA Astrophysics Data System (ADS)

    Tan, N.; Ramstein, G.; Contoux, C.; Ladant, J. B.; Dumas, C.; Donnadieu, Y.

    2014-12-01

    The insolation evolution [Laskar 2004] from 4 to 2.5 Ma depicts a series of three summer solstice insolation minima between 2.7 and 2.6 Ma, but there are other more important summer solstice minima notably around 3.82 and 3.05 Ma. On such a time span of more than 1 Ma, data shows that there are variations in the evolution of atmospheric CO2 concentration with a local maximum around 3 Ma [Seki et al.2010; Bartoli et al. 2011], before a decrease between 3 and 2.6 Ma. The latter, suggesting an abrupt ice sheet inception around 2.7 Ma, has been shown to be a major culprit for the full Greenland Glaciation [Lunt et al. 2008]. However, a recent study [Contoux et al. 2014, in review] suggests that a lowering of CO2 is not sufficient to initiate a glaciation on Greenland and must be combined to low summer insolation, with surviving ice during insolation maximum, suggesting a cumulative process in the first place, which could further lead to full glaciation at 2.7 Ma. Through a new tri-dimensional interpolation method implemented within the asynchronous coupling between an atmosphere ocean general circulation model (IPSL-CM5A) and an ice sheet model (GRISLI), we investigate the transient evolution of Greenland ice sheet during the Pliocene to diagnose whether the ice sheet inception is an abrupt event or rather a cumulative process, involving waxing and waning of the ice sheet during several orbital cycles. ReferencesBartoli, G., Hönisch, B., & Zeebe, R. E. (2011). Atmospheric CO2 decline during the Pliocene intensification of Northern Hemisphere glaciations. Paleoceanography, 26(4). Contoux C, Dumas C, Ramstein G, Jost A, Dolan A. M. (2014) Modelling Greenland Ice sheet inception and sustainability during the late Pliocene. (in review for Earth and Planetary Science Letters.).Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A. C. M., & Levrard, B. (2004). A long-term numerical solution for the insolation quantities of the Earth. Astronomy & Astrophysics, 428

  10. Lomonosov Ridge off Greenland (LOMROG) 2007

    NASA Astrophysics Data System (ADS)

    Marcussen, C.; Jakobsson, M.

    2007-12-01

    The Lomonosov Ridge off Greenland was the primary focus for the LOMROG expedition. This part of the Arctic is virtually unexplored as difficult sea ice conditions have made it inaccessible for surface vessels. With Swedish icebreaker /Oden/ supported by new Russian nuclear icebreaker /50 Let Pobedy/, LOMROG managed to reach the southern most tip of the Lomonosov Ridge off Greenland to carry out multibeam mapping, subbottom and seismic reflection profiling, gravity measurements, geological coring and oceanographic station work. The LOMROG expedition is a Swedish/Danish collaboration project with participating scientists also from Canada, Finland, and USA. The data collection was made for the purpose of studying paleoceanography/oceanography, glacial history and the tectonic evolution of the of the Arctic Ocean as well as for Denmark's Continental Shelf Project under the United Nations Convention on the Law of the Sea Article 76. One of the reasons for targeting the ice-infested area north of Greenland was that it likely holds answers to key questions regarding the glacial history of the Arctic Ocean, such as whether immense ice shelves existed in the Arctic Ocean during past glacial periods./ /Previous expeditions with /Oden/ in 1996 and the US nuclear submarine /Hawkbill/ in 1999, have demonstrated the occurrence of ice grounding down to 1000 m present water depth at about 87°N 145°E on the Lomonosov Ridge crest. If this ice grounding event resulted from a much debated, but supposedly coherent and large floating ice shelf, the Lomonosov Ridge north of Greenland must also be scoured. To test the hypothesis of a huge Arctic Ocean ice shelf LOMROG mapped the areas of the Lomonosov Ridge north of Greenland using the new EM120 multibeam bathymetry and SBP120 subbottom profiling system installed on the /Oden/ during the spring of 2007. Glacial erosion was indeed found at water depth shallower than approximately 800 m and two sediment cores retrieved from the glacially

  11. Responses of conventional and molecular biomarkers in turbot Scophthalmus maximus exposed to heavy fuel oil no. 6 and styrene.

    PubMed

    Ruiz, Pamela; Ortiz-Zarragoitia, Maren; Orbea, Amaia; Theron, Michael; Le Floch, Stéphane; Cajaraville, Miren P

    2012-07-15

    Several accidental spills in European coastal areas have resulted in the release of different toxic compounds into the marine environment, such as heavy fuel oil type no. 6 in the "Erika" and "Prestige" oil spills and the highly toxic styrene after the loss of the "Ievoli Sun". There is a clear need to develop tools that might allow assessing the biological impact of these accidental spills on aquatic organisms. The aim of the present study was to determine the short-term effects and recovery after exposure of juvenile fish (Scophthalmus maximus) to heavy fuel oil no. 6 and styrene by using a battery of molecular, cell and tissue level biomarkers. Turbots were exposed to styrene for 7 days and to the diluted soluble fraction of the oil (10%) for 14 days, and then allowed to recover in clean seawater for the same time periods. cyp1a1 transcript was overexpressed in turbots after 3 and 14 days of exposure to heavy fuel oil, whereas ahr transcription was not modulated after heavy fuel oil and styrene exposure. pparα transcription level was significantly up-regulated after 3 days of treatment with styrene. Liver activity of peroxisomal acyl-CoA oxidase (AOX) was significantly induced after 14 days of oil exposure, but it was not affected by styrene. Hepatocyte lysosomal membrane stability (LMS) was significantly reduced after exposure to both treatments, indicating that the tested compounds significantly impaired fish health. Both AOX and LMS values returned to control levels after the recovery period. No differences in gamete development were observed between fuel- or styrene- exposed fish and control fish, and vitellogenin plasma levels were low, suggesting no xenoestrogenic effects of fuel oil or styrene. While styrene did not cause any increase in the prevalence of liver histopathological alterations, prevalence of extensive cell vacuolization increased after exposure to heavy fuel oil for 14 days. In conclusion, the suite of selected biomarkers proved to be

  12. Rural Alaska Mentoring Project (RAMP)

    ERIC Educational Resources Information Center

    Cash, Terry

    2011-01-01

    For over two years the National Dropout Prevention Center (NDPC) at Clemson University has been supporting the Lower Kuskokwim School District (LKSD) in NW Alaska with their efforts to reduce high school dropout in 23 remote Yup'ik Eskimo villages. The Rural Alaska Mentoring Project (RAMP) provides school-based E-mentoring services to 164…

  13. Alaska Native Land Claims. [Textbook].

    ERIC Educational Resources Information Center

    Arnold, Robert D.; And Others

    Written for students at the secondary level, this textbook on Alaska Native land claims includes nine chapters, eight appendices, photographs, maps, graphs, bibliography, and an index. Chapters are titled as follows: (1) Earliest Times (Alaska's first settlers, eighteenth century territories, and other claimants); (2) American Indians and Their…

  14. Greenland surface albedo changes 1981-2012 from satellite observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Significant melt over Greenland has been observed during the last several decades associated with extreme warming events over the northern Atlantic Ocean. An analysis of surface albedo change over Greenland is presented, using a 32-year consistent satellite albedo product from the Global Land Surfac...

  15. GeoFORCE Alaska, A Successful Summer Exploring Alaska's Geology

    NASA Astrophysics Data System (ADS)

    Wartes, D.

    2012-12-01

    Thirty years old this summer, RAHI, the Rural Alaska Honors Institute is a statewide, six-week, summer college-preparatory bridge program at the University of Alaska Fairbanks for Alaska Native and rural high school juniors and seniors. This summer, in collaboration with the University of Texas Austin, the Rural Alaska Honors Institute launched a new program, GeoFORCE Alaska. This outreach initiative is designed to increase the number and diversity of students pursuing STEM degree programs and entering the future high-tech workforce. It uses Earth science to entice kids to get excited about dinosaurs, volcanoes and earthquakes, and includes physics, chemistry, math, biology and other sciences. Students were recruited from the Alaska's Arctic North Slope schools, in 8th grade to begin the annual program of approximately 8 days, the summer before their 9th grade year and then remain in the program for all four years of high school. They must maintain a B or better grade average and participate in all GeoFORCE events. The culmination is an exciting field event each summer. Over the four-year period, events will include trips to Fairbanks and Anchorage, Arizona, Oregon and the Appalachians. All trips focus on Earth science and include a 100+ page guidebook, with tests every night culminating with a final exam. GeoFORCE Alaska was begun by the University of Alaska Fairbanks in partnership with the University of Texas at Austin, which has had tremendous success with GeoFORCE Texas. GeoFORCE Alaska is managed by UAF's long-standing Rural Alaska Honors Institute, that has been successfully providing intense STEM educational opportunities for Alaskan high school students for over 30 years. The program will add a new cohort of 9th graders each year for the next four years. By the summer of 2015, GeoFORCE Alaska is targeting a capacity of 160 students in grades 9th through 12th. Join us to find out more about this exciting new initiative, which is enticing young Alaska Native

  16. 2013 Alaska Performance Scholarship Outcomes Report

    ERIC Educational Resources Information Center

    Rae, Brian

    2013-01-01

    In accordance with Alaska statute the departments of Education & Early Development (EED) and Labor and Workforce Development (DOLWD), the University of Alaska (UA), and the Alaska Commission on Postsecondary Education (ACPE) present this second annual report on the Alaska Performance Scholarship (APS). Among the highlights: (1) In the public…

  17. Brief communication "The aerophotogrammetric map of Greenland ice masses"

    NASA Astrophysics Data System (ADS)

    Citterio, M.; Ahlstrøm, A. P.

    2013-03-01

    The PROMICE (Programme for Monitoring of the Greenland Ice Sheet) aerophotogrammetric map of Greenland ice masses is the first high resolution dataset documenting the mid-1980s areal extent of the Greenland Ice Sheet and all the local glaciers and ice caps. The total glacierized area excluding nunataks was 1 804 638 km2 ± 2178 km2, of which 88 083 ± 1240 km2 belonged to local glaciers and ice caps (GIC) substantially independent from the Greenland Ice Sheet. This new result of GIC glacierized area is higher than most previous estimates, 81% greater than Weng's (1995) measurements, but is in line with contemporary findings based on independent data sources. A comparison between our map and the recently released Rastner et al. (2012) inventory and GIMP (Greenland Ice Mapping Project) Ice-Cover Mask (Howat and Negrete, 2013) shows potential for change-assessment studies.

  18. Accumulation rates in Northwest Greenland from continuous GPR profiling along the Greenland Inland Traverse

    NASA Astrophysics Data System (ADS)

    Hawley, R. L.; Courville, Z.; Kehrl, L. M.; Lutz, E.; Osterberg, E. C.; Overly, T. B.; Wong, G. J.

    2012-12-01

    Snow accumulation is one of the fundamental parameters governing the mass balance of the Greenland Ice Sheet. While many point measurements of accumulation exist from shallow and deep ice cores, there are few spatially extensive and continuous records of accumulation in Greenland, particularly in the northwest quadrant. In April and May 2011, the Greenland Inland Traverse traveled via tractor train from Thule Air Base in northwest Greenland to Summit Station, at the center of the ice sheet. The science team on the traverse collected both point and profile measurements along the route. Kinematic GPS and 400 MHz GPR profiles provide geolocated subsurface stratigraphy. Density measurements from snowpits and shallow cores on the profile allow us to determine the true depth of radar reflecting horizons, commonly interpreted to be isochrons. We use three ice cores collected at the beginning, the end, and roughly the middle of the route to date horizons. We traced strong reflecting horizons along the entire route. From the combination of dated, traced horizons, density measurements, and position measurements, we determine accumulation rates continuously along the traverse route. We find our traverse route begins in a high-accumulation area, and accumulation decreases as we cross to the east side of the summit ridge. Accumulation then climbs again as we approach summit (directly on the summit ridge). We compare our accumulation rates with previous studies, both measurements (traverse and point measurements) and models.

  19. The East Greenland Ridge - a continental sliver along the Greenland Fracture Zone

    NASA Astrophysics Data System (ADS)

    Gerlings, Joanna; Funck, Thomas; Castro, Carlos F.; Hopper, John R.

    2014-05-01

    The East Greenland Ridge (EGR), situated along the Greenland Fracture Zone in the northern part of the Greenland-Norwegian Sea, is a NW-SE trending 250-km-long and up to 50-km-wide bathymetric high that separates the Greenland Basin in the south from the Boreas Basin in the north. Previous seismic work established that the EGR is primarily continental in nature. Detailed swath bathymetric data revealed a complex internal structure of the ridge with two main overstepping ridge segments. These segments were not adequately covered by the GEUS2002NEG seismic survey as the detailed structure was not known at that time. The crustal affinity of the northwestern, landward-most ridge segment, and how it is attached to the Northeast Greenland continental shelf, remained unclear. The GEUS-EAGER2011 survey was designed to address these issues and to provide further constraints on the structural development of the EGR. During the GEUS-EAGER2011 survey, additional seismic refraction and reflection data were acquired on the EGR and the Northeast Greenland shelf. The data set consists of two strike lines covering the seaward-most part of the Northeast Greenland shelf and the landward-most part of the EGR, and one cross line extending from the Boreas Basin, across the ridge and into the Greenland Basin. A total of 15 ocean bottom seismometers and 46 sonobuoys were deployed along the three seismic refraction lines. P-wave velocity models for the crust and upper mantle were derived by forward and inverse modelling of the travel times of the observed seismic phases using the raytracing algorithm RAYINVR. Seismic reflection data, coinciding with the seismic refraction data were used to guide the modelling of the sedimentary layers down to basement. The velocity models confirm that the crust has a continental nature along both ridge segments with a velocity structure that significantly differs from that of normal oceanic crust. The models also show that the crust of the EGR is linked to

  20. Geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

    USGS Publications Warehouse

    Wilson, Frederic H.; Detterman, Robert L.; DuBois, Gregory D.

    2015-01-01

    The boundaries separating the Alaska Peninsula terrane from other terranes are commonly indistinct or poorly defined. A few boundaries have been defined at major faults, although the extensions of these faults are speculative through some areas. The west side of the Alaska Peninsula terrane is overlapped by Tertiary s

  1. Geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

    USGS Publications Warehouse

    Wilson, Frederic H.; Detterman, Robert L.; DuBois, Gregory D.

    2015-01-01

    The boundaries separating the Alaska Peninsula terrane from other terranes are commonly indistinct or poorly defined. A few boundaries have been defined at major faults, although the extensions of these faults are speculative through some areas. The west side of the Alaska Peninsula terrane is overlapped by Tertiary sedimentary and volcanic rocks and Quaternary deposits.

  2. Expression of insulin-like growth factors at mRNA levels during the metamorphic development of turbot (Scophthalmus maximus).

    PubMed

    Meng, Zhen; Hu, Peng; Lei, Jilin; Jia, Yudong

    2016-09-01

    Insulin-like growth factors I and II (IGF-I and IGF-II) are important regulators of vertebrate growth and development. This study characterized the mRNA expressions of igf-i and igf-ii during turbot (Scophthalmus maximus) metamorphosis to elucidate the possible regulatory role of the IGF system in flatfish metamorphosis. Results showed that the mRNA levels of igf-i significantly increased at the early-metamorphosis stage and then gradually decreased until metamorphosis was completed. By contrast, mRNA levels of igf-ii significantly increased at the pre-metamorphosis stage and then substantially decreased during metamorphosis. Meanwhile, the whole-body thyroxine (T4) levels varied during larval metamorphosis, and the highest value was observed in the climax-metamorphosis. The mRNA levels of igf-i significantly increased and decreased by T4 and thiourea (TU, inhibitor of endogenous thyroid hormone) during metamorphosis, respectively. Conversely, the mRNA levels of igf-ii remained unchanged. Furthermore, TU significantly inhibited the T4-induced mRNA up-regulation of igf-i during metamorphosis. The whole-body thyroxine (T4) levels were significantly increased and decreased by T4 and TU during metamorphosis, respectively. These results suggested that igf-i and igf-ii may play different functional roles in larval development stages, and igf-i may have a crucial function in regulating the early metamorphic development of turbot. These findings may enhance our understanding of the potential roles of the IGF system to control flatfish metamorphosis and contribute to the improvement of broodstock management for larvae.

  3. Protein-sparing effect of carbohydrate in diets for juvenile turbot Scophthalmus maximus reared at different salinities

    NASA Astrophysics Data System (ADS)

    Zeng, Lin; Lei, Jilin; Ai, Chunxiang; Hong, Wanshu; Liu, Bin

    2015-01-01

    The aim of the present study was to investigate the protein-sparing effect of carbohydrate in diets for juvenile turbot ( Scophthalmus maximus) reared at five salinities (12, 18, 24, 30, and 36). The fish were fed three isocaloric and isolipidic diets for 60 days. The results show that specific growth rate (SGR) and feed conversion efficiency (FCE) were higher in fish reared at salinities of 18 and 36, but lower at 12. Fish fed with diet C25P40 (25% carbohydrate and 40% protein) had lower SGR and FCE values compared with those fed with the C5P52 (5% carbohydrate and 52% protein) and C15P46 (15% carbohydrate and 46% protein) diets; however, there was no statistical difference between diet C5P52 and C15P46. SGR and FCE values were unaffected by diet composition in fish reared at salinity 36. Hepatic lipogenic enzyme activities were higher in fish reared at 18 and 36, but lower at 12, while glucokinase (GK) activity was higher in fish reared at 12, and lower at 18 and 36. Dietary starch enhanced GK activity while depressing lipogenic enzyme activity. However, lipogenic enzyme activity increased with increasing dietary starch in fish reared at 36. It is recommended that salinity should be maintained >12 in the farming of juvenile turbot. In addition, an increase in gelatinized starch from 5% to 15% could spare 6% dietary protein in fish reared at salinities of 18-30, while higher salinity (36) could improve dietary carbohydrate use and enhance the protein-sparing effect, which is linked with the induction of lipogenic capacities.

  4. Expression of insulin-like growth factors at mRNA levels during the metamorphic development of turbot (Scophthalmus maximus).

    PubMed

    Meng, Zhen; Hu, Peng; Lei, Jilin; Jia, Yudong

    2016-09-01

    Insulin-like growth factors I and II (IGF-I and IGF-II) are important regulators of vertebrate growth and development. This study characterized the mRNA expressions of igf-i and igf-ii during turbot (Scophthalmus maximus) metamorphosis to elucidate the possible regulatory role of the IGF system in flatfish metamorphosis. Results showed that the mRNA levels of igf-i significantly increased at the early-metamorphosis stage and then gradually decreased until metamorphosis was completed. By contrast, mRNA levels of igf-ii significantly increased at the pre-metamorphosis stage and then substantially decreased during metamorphosis. Meanwhile, the whole-body thyroxine (T4) levels varied during larval metamorphosis, and the highest value was observed in the climax-metamorphosis. The mRNA levels of igf-i significantly increased and decreased by T4 and thiourea (TU, inhibitor of endogenous thyroid hormone) during metamorphosis, respectively. Conversely, the mRNA levels of igf-ii remained unchanged. Furthermore, TU significantly inhibited the T4-induced mRNA up-regulation of igf-i during metamorphosis. The whole-body thyroxine (T4) levels were significantly increased and decreased by T4 and TU during metamorphosis, respectively. These results suggested that igf-i and igf-ii may play different functional roles in larval development stages, and igf-i may have a crucial function in regulating the early metamorphic development of turbot. These findings may enhance our understanding of the potential roles of the IGF system to control flatfish metamorphosis and contribute to the improvement of broodstock management for larvae. PMID:27255364

  5. Continuous broadband seismic observation on the Greenland Ice Sheet under Greenland Ice Sheet monitoring Network

    NASA Astrophysics Data System (ADS)

    Tsuboi, Seiji; Kanao, Masaki; Tono, Yoko; Himeno, Tetsuto; Toyokuni, Genti; Childs, Dean; Dahl-Jensen, Trine; anderson, Kent

    2013-04-01

    We have installed the ice sheet broadband seismograph station, called ICE-S (DK.ICESG) in June 2011, in collaboration with IRIS Polar Services under the GreenLand Ice Sheet monitoring Network (GLISN), which is a new, international, broadband seismic capability for Greenland being implemented through the collaboration between Denmark, Canada, France, Germany, Italy, Japan, Norway, Poland, Switzerland, and the USA. The primary purpose of GLISN project is to define the fine structure and detailed mechanisms of glacial earthquakes within the Greenland Ice Sheet. These glacial earthquakes in the magnitude range 4.6-5.1 may be modeled as a large glacial ice mass sliding downhill several meters on its basal surface over duration of 30 to 60 seconds. Glacial earthquakes have been observed at seismic stations within Greenland (Larsen et al, 2006), but the coverage was very sparse and a broadband, real-time seismic network was needed to be installed throughout Greenland's Ice Sheet and perimeter. The National Institute for Polar Research and Japan Agency for Marine-Earth Science and Technology are members of GLISN project and we have started to operate ICESG station since 2011. The station is equipped with a CMG-3T broadband seismometer and a Quanterra Q330 data logger. We have visited the station again in May, 2012 and successfully retrieved one year of continuous records from the broadband seismometer and updated the telemetry system to eventually allow real time monitoring of the station. ICESG station is now daily sending 1 Hz continuous data over the iridium satellite system using RUDICS. The observed three component seismograms demonstrate that the quality of this ice sheet station is good enough to record not only local earthquakes around Greeland but also teleseismic earthquakes. We could record three component broadband seismograms for April 11, 2012 Off the west coast of Northern Sumatra earthquake (Mw8.6). These seismograms show high signal to noise ratio

  6. 78 FR 53137 - Flint Hills Resources Alaska, LLC, BP Pipelines (Alaska) Inc., ConocoPhillips Transportation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ...Phillips Transportation Alaska, Inc., ExxonMobil Pipeline Company; Notice of Complaint Take notice that on... formal complaint against BP Pipelines (Alaska) Inc., ConocoPhillips Transportation Alaska, Inc.,...

  7. Clouds enhance Greenland ice sheet mass loss

    NASA Astrophysics Data System (ADS)

    Van Tricht, Kristof; Gorodetskaya, Irina V.; L'Ecuyer, Tristan; Lenaerts, Jan T. M.; Lhermitte, Stef; Noel, Brice; Turner, David D.; van den Broeke, Michiel R.; van Lipzig, Nicole P. M.

    2015-04-01

    Clouds have a profound influence on both the Arctic and global climate, while they still represent one of the key uncertainties in climate models, limiting the fidelity of future climate projections. The potentially important role of thin liquid-containing clouds over Greenland in enhancing ice sheet melt has recently gained interest, yet current research is spatially and temporally limited, focusing on particular events, and their large scale impact on the surface mass balance remains unknown. We used a combination of satellite remote sensing (CloudSat - CALIPSO), ground-based observations and climate model (RACMO) data to show that liquid-containing clouds warm the Greenland ice sheet 94% of the time. High surface reflectivity (albedo) for shortwave radiation reduces the cloud shortwave cooling effect on the absorbed fluxes, while not influencing the absorption of longwave radiation. Cloud warming over the ice sheet therefore dominates year-round. Only when albedo values drop below ~0.6 in the coastal areas during summer, the cooling effect starts to overcome the warming effect. The year-round excess of energy due to the presence of liquid-containing clouds has an extensive influence on the mass balance of the ice sheet. Simulations using the SNOWPACK snow model showed not only a strong influence of these liquid-containing clouds on melt increase, but also on the increased sublimation mass loss. Simulations with the Community Earth System Climate Model for the end of the 21st century (2080-2099) show that Greenland clouds contain more liquid water path and less ice water path. This implies that cloud radiative forcing will be further enhanced in the future. Our results therefore urge the need for improving cloud microphysics in climate models, to improve future projections of ice sheet mass balance and global sea level rise.

  8. Cenozoic Motion of Greenland - Overlaps and Seaways

    NASA Astrophysics Data System (ADS)

    Lawver, L. A.; Norton, I. O.; Gahagan, L.

    2014-12-01

    Using the seafloor magnetic anomalies found in the Labrador Sea, North Atlantic and Eurasian basin to constrain the Cenozoic motion of Greenland, we have produced a new model for the tectonic evolution of the region. The aeromagnetic data collected by the Naval Research Lab [Brozena et al., 2003] in the Eurasian Basin and Canadian data from the Labrador Sea have been re-evaluated using new gridding algorithms and profile modeling using ModMag (Mendel et al., 2005). As a consequence, we have changed the published correlations, mostly prior to Chron C6 [19.05 Ma]. Presently published seafloor magnetic anomalies from the Labrador Sea assume that seafloor spreading ceased at C13 [33.06 Ma] but such an assumption produces an unacceptable overlap of Kronprins Christian Land of northeast Greenland with Svalbard, up to 140 km of overlap in some models. Our new model does not need any "unacceptable" overlap but does produce a slight amount of Eocene compression on Svalbard as is found on land there. Our model allows for an Early Eocene seaway between Ellesmere Island and northwest Greenland that may have connected the Labrador Sea through Baffin Bay and ultimately to the nascent Eurasian Basin, although its depth or even its essential existence is unknowable. During the Miocene, there is no room for a deepwater seaway in Fram Strait until at least the very end of the Early Miocene and perhaps not until Middle Miocene. Brozena, J. and six others, 2003. New aerogeophysical study of the Eurasia Basin and Lomonosov Ridge: Implications for basin development. Geology 31, 825-828. Mendel, V., M. Munschy and D.Sauter, 2005, MODMAG, a MATLAB program to model marine magnetic anomalies, Comp. Geosci., 31, .589-597

  9. Expression analysis of the insulin-like growth factors I and II during embryonic and early larval development of turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Wen, Haishen; Qi, Qian; Hu, Jian; Si, Yufeng; He, Feng; Li, Jifang

    2015-04-01

    The insulin-like growth factors I and II (IGF-I and IGF-II) are important proteins involved in fish growth and development. Here, we report the isolation of IGF-II and expression analysis of IGFs in turbot Scophthalmus maximus, aiming to clarify their function in embryonic and larval development of fish. The deduced IGF-II gene is 808 bp in full length, which encodes a protein of 219 amino acids and is 93% similar with that of Paralichthys olicaceus in amino acid sequence. The tissue abundance and the expression pattern of IGFs in a turbot at early development stages were investigated via reverse transcription-polymer chain reaction. Result showed that the IGF-I and IGF-II genes were widely expressed in tissues of S. maximus. IGF-I was detected in all tissues except intestines with the highest level in liver, while IGF-II transcript presented in all tissues except muscle. At the stages of embryonic and larval development, the mRNA levels of IGFs sharply increased from the stage of unfertilized egg to post larva, followed by a decrease with larval development. However, there was an increase in IGF-I at the embryonic stage and IGF-II at the gastrula stage, respectively. These results suggested that IGFs play important roles in cell growth and division of the turbot. Our study provides reference data for further investigation of growth regulation in turbot, which can guarantee better understanding of the physiological role that IGFs play in fish.

  10. The recent warming trend in North Greenland

    NASA Astrophysics Data System (ADS)

    Orsi, Anais; Kawamura, Kenji; Masson-Delmotte, Valerie; Landais, Amaelle; Severinghaus, Jeff

    2015-04-01

    The arctic is the fastest warming region on Earth, but it is also one where there is little historical data. Although summer warming causes melt, the annual temperature trend is dominated by the winter and fall season, which are much less well documented. In addition, the instrumental record relies principally on coastal weather stations, and there are very few direct temperature observations in the interior dating back more than 30 years, especially in North Greenland, where the current warming trend is the largest. Here, we present a temperature reconstruction from NEEM (51°W, 77°N), in North Greenland, for the last 100 years, which allows us to put the recent trend in the context of the longer term climate. We use a combination of two independent proxies to reconstruct the temperature history at NEEM: borehole temperature and inert gas isotope measurements in the firn. Borehole temperature takes advantage of the low temperature diffusivity of the snow and ice, which allows the temperature history to be preserved in the ice for several centuries. Temperature gradients in the firn (old snow above the ice) influence the gas isotopic composition: thermal fractionation causes heavy isotopes to concentrate on the cold end of the firn column. We measured the isotopes of inert gases (N2, Ar and Kr), which have a constant atmospheric composition through time, and use the thermal fractionation signal as an additional constraint on the temperature history at the site. We find that NEEM has been warming by 0.86±0.22°C/decade over the past 30 years, from -28.55±0.29°C for the 1900-1970 average to -26.77±0.16°C for the 2000-2010 average. The warming rate at NEEM is similar to that of Greenland Summit, and confirms the large warming trends in North Greenland (polar amplification) and high altitude sites (tropospheric rather than surface warming). Water isotopes show that the recent past has not met the level of the 1928 anomaly; but the average of the past 30 years has

  11. Growth of Greenland ice sheet - Measurement

    NASA Technical Reports Server (NTRS)

    Zwally, H. Jay; Bindschadler, Robert A.; Marsh, James G.; Brenner, Anita C.; Major, Judy A.

    1989-01-01

    Measurements of ice-sheet elevation change by satellite altimetry show that the Greenland surface elevation south of 72 deg north latitude is increasing. The vertical velocity of the surface is 0.20 + or - 0.06 meters/year from measured changes in surface elevations at 5906 intersections between Geosat paths in 1985 and Seasat in 1978, and 0.28 + or - 0.02 meters/year from 256,694 intersections of Geosat paths during a 548-day period of 1985 to 1986.

  12. Towards Introducing a Geocoding Information System for Greenland

    NASA Astrophysics Data System (ADS)

    Siksnans, J.; Pirupshvarre, Hans R.; Lind, M.; Mioc, D.; Anton, F.

    2011-08-01

    Currently, addressing practices in Greenland do not support geocoding. Addressing points on a map by geographic coordinates is vital for emergency services such as police and ambulance for avoiding ambiguities in finding incident locations (Government of Greenland, 2010) Therefore, it is necessary to investigate the current addressing practices in Greenland. Asiaq (Asiaq, 2011) is a public enterprise of the Government of Greenland which holds three separate databases regards addressing and place references: - list of locality names (towns, villages, farms), - technical base maps (including road center lines not connected with names, and buildings), - the NIN registry (The Land Use Register of Greenland - holds information on the land allotments and buildings in Greenland). The main problem is that these data sets are not interconnected, thus making it impossible to address a point in a map with geographic coordinates in a standardized way. The possible solutions suffer from the fact that Greenland has a scattered habitation pattern and the generalization of the address assignment schema is a difficult task. A schema would be developed according to the characteristics of the settlement pattern, e.g. cities, remote locations and place names. The aim is to propose an ontology for a common postal address system for Greenland. The main part of the research is dedicated to the current system and user requirement engineering. This allowed us to design a conceptual database model which corresponds to the user requirements, and implement a small scale prototype. Furthermore, our research includes resemblance findings in Danish and Greenland's addressing practices, data dictionary for establishing Greenland addressing system's logical model and enhanced entity relationship diagram. This initial prototype of the Greenland addressing system could be used to evaluate and build the full architecture of the addressing information system for Greenland. Using software engineering

  13. Immunohistochemical study of inducible nitric oxide synthase and tumour necrosis factor alpha response in turbot (Scophthalmus maximus) experimentally infected with Aeromonas salmonicida subsp. salmonicida.

    PubMed

    Coscelli, Germán; Bermúdez, Roberto; Ronza, Paolo; Losada, Ana Paula; Quiroga, María Isabel

    2016-09-01

    Aeromonas salmonicida subsp. salmonicida represents one of the major threats in aquaculture, especially in salmonid fish and turbot farming. In order to fight bacterial infections, fish have an immune system composed by innate and specific cellular and humoral elements analogous to those present in mammals. However, innate immunity plays a primordial role against bacterial infections in teleost fish. Among these non-specific mechanisms, the production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) pathway and the tumour necrosis factor-alpha (TNFα) produced by mononuclear phagocytes, are two of the main immune effectors to eliminate bacterial pathogens. In this study, the distribution and kinetic of iNOS and TNFα-producing cells of kidney and spleen of turbot experimentally inoculated with A. salmonicida was assessed by immunohistochemistry. In control and challenged fish, individual iNOS(+) and TNFα(+) cells, showing a similar pattern of distribution, were detected. In challenged fish, the number of immunoreactive cells was significantly increased in the evaluated organs, as well as the melanomacrophage centres showed variable positivity for both antigens. These results indicate that A. salmonicida induced an immune response in challenged turbot, which involved the increase of the activity of iNOS and TNFα in the leukocytic population from kidney and spleen. PMID:27431586

  14. Characterization and expression analysis of a peptidoglycan recognition protein gene, SmPGRP2 in mucosal tissues of turbot (Scophthalmus maximus L.) following bacterial challenge.

    PubMed

    Zhang, Linan; Gao, Chengbin; Liu, Fengqiao; Song, Lin; Su, Baofeng; Li, Chao

    2016-09-01

    Peptidoglycan recognition receptor proteins (PGRPs), a group of pattern recognition receptors (PRRs), can recognize peptidoglycan (PGN) of the bacteria cell wall and play an important role in host immune defense against pathogen infection. They are highly structurally conserved through evolution, but with different function in innate immunity between invertebrates and vertebrates. In teleost fish, several PGRPs have been characterized recently. They have both amidase activity and bactericidal activity and are involved in indirectly killing bacteria and regulating multiple signaling pathways. However, the knowledge of PGRPs in mucosal immunity of teleost fish is still limited. In this study, we identified a PGRPs gene (SmPGRP2) of turbot and investigated its expression patterns in mucosal tissues after challenge with Gram-positive bacteria Streptococcus iniae and Gram-negative bacteria Vibrio anguillarum. Phylogenetic analysis showed the strongest relationship of turbot PGRP to halibut, which was consistent with their phylogenetic relationships. In addition, SmPGRP2 was ubiquitously expressed in turbot tissues, and constitutive expression levels were higher in classical immune tissues (including liver, spleen, and head-kidney) than mucosal tissues (intestine, gill and skin). After bacterial challenge, the expression of SmPGRP2 was induced and showed a general trend of up-regulation in mucosal tissues, except in intestine following V. anguillarum infection. These different expression patterns varied depending on both pathogen and tissue type, suggesting its distinct roles in the host immune response to bacterial pathogen. PMID:27461422

  15. Immunohistochemical study of inducible nitric oxide synthase and tumour necrosis factor alpha response in turbot (Scophthalmus maximus) experimentally infected with Aeromonas salmonicida subsp. salmonicida.

    PubMed

    Coscelli, Germán; Bermúdez, Roberto; Ronza, Paolo; Losada, Ana Paula; Quiroga, María Isabel

    2016-09-01

    Aeromonas salmonicida subsp. salmonicida represents one of the major threats in aquaculture, especially in salmonid fish and turbot farming. In order to fight bacterial infections, fish have an immune system composed by innate and specific cellular and humoral elements analogous to those present in mammals. However, innate immunity plays a primordial role against bacterial infections in teleost fish. Among these non-specific mechanisms, the production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) pathway and the tumour necrosis factor-alpha (TNFα) produced by mononuclear phagocytes, are two of the main immune effectors to eliminate bacterial pathogens. In this study, the distribution and kinetic of iNOS and TNFα-producing cells of kidney and spleen of turbot experimentally inoculated with A. salmonicida was assessed by immunohistochemistry. In control and challenged fish, individual iNOS(+) and TNFα(+) cells, showing a similar pattern of distribution, were detected. In challenged fish, the number of immunoreactive cells was significantly increased in the evaluated organs, as well as the melanomacrophage centres showed variable positivity for both antigens. These results indicate that A. salmonicida induced an immune response in challenged turbot, which involved the increase of the activity of iNOS and TNFα in the leukocytic population from kidney and spleen.

  16. Different impact of heat-inactivated and viable lactic acid bacteria of aquatic origin on turbot (Scophthalmus maximus L.) head-kidney leucocytes.

    PubMed

    Muñoz-Atienza, Estefanía; Araújo, Carlos; Lluch, Nuria; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M; Magadán, Susana

    2015-05-01

    In aquaculture, several criteria should be considered to select an appropriate probiotic, including the aquatic origin and safety of the strain and its ability to modulate the host immune response. The properties and effects of probiotics are strain-specific and some factors such as viability, dose and duration of diet supplementation may regulate their immunomodulatory activities. In this study, we assessed the in vitro effect of eight heat-inactivated and viable lactic acid bacteria (LAB) of aquatic origin belonging to the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella on the viability and innate immune response of turbot (Scophthalmus maximus L.) leucocytes. Head-kidney leucocytes were incubated with viable and heat-inactivated LAB at different concentrations. After incubation, the viability of leucocytes was evaluated using colorimetric assays (MTT and LDH) and flow cytometry (annexin V/propidium iodide). Heat-inactivated LAB showed no cytotoxic effect while viable LAB exerted variable influence on apoptosis of turbot phagocytes and lymphocytes. Leucocyte respiratory burst activity and phagocytosis were also differentially activated, as viable LAB stimulated leucocytes more efficiently than the heat-inactivated LAB. Our results suggest diverse strain-specific mechanisms of interaction between the evaluated LAB and turbot leucocytes. Furthermore, our work sets up in vitro systems to evaluate the effect of LAB as potential probiotics, which will be useful to develop efficient screening.

  17. Different impact of heat-inactivated and viable lactic acid bacteria of aquatic origin on turbot (Scophthalmus maximus L.) head-kidney leucocytes.

    PubMed

    Muñoz-Atienza, Estefanía; Araújo, Carlos; Lluch, Nuria; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M; Magadán, Susana

    2015-05-01

    In aquaculture, several criteria should be considered to select an appropriate probiotic, including the aquatic origin and safety of the strain and its ability to modulate the host immune response. The properties and effects of probiotics are strain-specific and some factors such as viability, dose and duration of diet supplementation may regulate their immunomodulatory activities. In this study, we assessed the in vitro effect of eight heat-inactivated and viable lactic acid bacteria (LAB) of aquatic origin belonging to the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella on the viability and innate immune response of turbot (Scophthalmus maximus L.) leucocytes. Head-kidney leucocytes were incubated with viable and heat-inactivated LAB at different concentrations. After incubation, the viability of leucocytes was evaluated using colorimetric assays (MTT and LDH) and flow cytometry (annexin V/propidium iodide). Heat-inactivated LAB showed no cytotoxic effect while viable LAB exerted variable influence on apoptosis of turbot phagocytes and lymphocytes. Leucocyte respiratory burst activity and phagocytosis were also differentially activated, as viable LAB stimulated leucocytes more efficiently than the heat-inactivated LAB. Our results suggest diverse strain-specific mechanisms of interaction between the evaluated LAB and turbot leucocytes. Furthermore, our work sets up in vitro systems to evaluate the effect of LAB as potential probiotics, which will be useful to develop efficient screening. PMID:25707601

  18. Trans-Alaska pipeline

    SciTech Connect

    Not Available

    1991-07-01

    The Trans-Alaska Pipeline system transports nearly 25 percent of the nation's domestically produced crude oil. Since operations began in 1977, the system has delivered over 8 billion barrels of oil to Port Veldez for shipment. This paper reports that concerns have been raised about whether the system is meeting special engineering design and operations requirements imposed by federal and state regulators. GAO found that the five principal federal and state regulatory agencies have not pursued a systematic, disciplined, and coordinated approach to regulating the Trans-Alaska Pipeline System. Instead, these agencies have relied on the Alyeska Pipeline Service Company, which runs the system, to police itself. It was only after the Exxon Valdez spill and the discovery of corrosion that the regulators began to reevaluate their roles and focus on issues such as whether Alyeska's operating and maintenance procedures meet the pipelines, special engineering design and operating requirements, or whether Alyeska can adequately respond to a large oil spill. In January 1990, the regulators established a joint office to provide more effective oversight of the system. GAO believes that central leadership and a secured funding sources may help ensure that this office provides adequate oversight.

  19. Metamorphic facies map of Alaska

    SciTech Connect

    Dusel-Bacon, C.; O-Rourke, E.F.; Reading, K.E.; Fitch, M.R.; Klute, M.A.

    1985-04-01

    A metamorphic-facies of Alaska has been compiled, following the facies-determination scheme of the Working Group for the Cartography of the Metamorphic Belts of the World. Regionally metamorphosed rocks are divided into facies series where P/T gradients are known and into facies groups where only T is known. Metamorphic rock units also are defined by known or bracketed age(s) of metamorphism. Five regional maps have been prepared at a scale of 1:1,000,000; these maps will provide the basis for a final colored version of the map at a scale of 1:2,500,000. The maps are being prepared by the US Geological Survey in cooperation with the Alaska Division of Geological and Geophysical Surveys. Precambrian metamorphism has been documented on the Seward Peninsula, in the Baird Mountains and the northeastern Kuskokwim Mountains, and in southwestern Alaska. Pre-Ordovician metamorphism affected the rocks in central Alaska and on southern Prince of Wales Island. Mid-Paleozoic metamorphism probably affected the rocks in east-central Alaska. Most of the metamorphic belts in Alaska developed during Mesozoic or early Tertiary time in conjuction with accretion of many terranes. Examples are Jurassic metamorphism in east-central Alaska, Early Cretaceous metamorphism in the southern Brooks Range and along the rim of the Yukon-Kovyukuk basin, and late Cretaceous to early Tertiary metamorphism in the central Alaska Range. Regional thermal metamorphism was associated with multiple episodes of Cretaceous plutonism in southeastern Alaska and with early Tertiary plutonism in the Chugach Mountains. Where possible, metamorphism is related to tectonism. Meeting participants are encouraged to comment on the present version of the metamorphic facies map.

  20. Mental disorders in the Greenlandic population. A register study.

    PubMed

    Lynge, I; Mortensen, P B; Munk-Jørgensen, P

    1999-07-01

    In a register study of all psychiatric first hospitalizations (1974-93) of persons born and resident in Greenland rates for all admissions as well as for the separate diagnostic groups, hierarchically organized, were compared with corresponding figures for the population in Denmark. Relative mortality rates for the psychiatric patients compared with the general population were computed for the Greenlandic and Danish populations respectively. No significant differences in the total pattern of hospitalization was found, but Greenlandic men 15-24 years old and Greenlandic women 25-34 years old had significantly higher and older age groups lower first admission rates than Danish men and women, respectively. The rates for affective psychoses were low especially among men in Greenland, whereas the rates for schizophrenia among men were comparatively high. The relative mortality risk compared to the general population was much higher among Danish than Greenlandic psychiatric patients, especially regarding suicide. A probable explanation for that is that the suicide rate in the Green-landic general population is very high.

  1. Variability in the East Greenland Current

    NASA Astrophysics Data System (ADS)

    Holfort, J.; Meincke, J.; Mortensen, J.

    2003-04-01

    The East Greenland Current (EGC) carries different water masses along the eastern coast of Greenland to the south. Denmark Strait overflow water (DSOW) is a mixture of these southward flowing water masses. The Polar Water part (liquid and ice) is the main oceanic fresh water source for the North Atlantic. Changes in the composition of the EGC can therefore have considerable impact also on the larger scale (e.g. the global thermohaline circulation). We will give a picture of the variability of the water mass characteristics of the EGC based on oceanic data and discuss possible effect onto the DSOW. For the shorter term variability the main data sources are recent hydrographic data; and temperature, salinity and current data from a mooring array across the EGC at 75°N. The mooring data spans 2 years (9/2000-9/2002) for deep bottom part and 1 year (9/2001-9/2002) for the upper water column. For longer term (>2 years) variability the main source are historical and recent hydrografic data.

  2. Anthropogenic carbon in the East Greenland Current

    NASA Astrophysics Data System (ADS)

    Jutterström, Sara; Jeansson, Emil

    2008-07-01

    Sections of dissolved inorganic anthropogenic carbon ( CTanthro) based on 2002 data in the East Greenland Current (EGC) are presented. The CTanthro has been estimated using a model based on optimum multiparameter analysis with predefined source water types. Values of CTanthro have been assigned to the source water types through age estimations based on the transit time distribution (TTD) technique. The validity of this approach is discussed and compared to other methods. The results indicated that the EGC had rather high levels of CTanthro in the whole water column, and the anthropogenic signal of the different source areas were detected along the southward transit. We estimated an annual transport of CTanthro with the Denmark Strait overflow ( σθ > 27.8 kg m -3) of ∼0.036 ± 0.005 Gt C y -1. The mean CTanthro concentration in this density range was ∼30 μmol kg -1. The main contribution was from Atlantic derived waters, the Polar Intermediate Water and the Greenland Sea Arctic Intermediate Water.

  3. Pathways of Petermann Glacier meltwater, Greenland

    NASA Astrophysics Data System (ADS)

    Heuzé, Céline; Wåhlin, Anna; Johnson, Helen; Münchow, Andreas

    2016-04-01

    Radar and satellite observations suggest that the floating ice shelf of Petermann Glacier loses up to 80% of its mass through basal melting, caused by the intrusion of warm Atlantic Water into the fjord and under the ice shelf. The fate of Petermann's glacial meltwater is still largely unknown. It is investigated here, using hydrographic observations collected during a research cruise on board I/B Oden in August 2015. Two methods are used to detect the meltwater from Petermann: a mathematical one that provides the concentration of ice shelf meltwater, and a geometrical one to distinguish the meltwater from Petermann and the meltwater from other ice shelves. The meltwater from Petermann mostly circulates on the north side of the fjord. At the sill, 0.5 mSv of meltwater leave the fjord, mostly on the northeastern side between 100 and 350 m depth, but also in the central channel, albeit with a lesser concentration. Meltwater from Petermann is found in all the casts in Hall Basin, notably north of the sill by Greenland coast. The geometrical method reveals that the casts closest to the Canadian side mostly contain meltwater from other, unidentified glaciers. As Atlantic Water warms up, it is key to monitor Greenland melting glaciers and track their meltwater to properly assess their impact on the ocean circulation and sea level rise.

  4. Robots could assist scientists working in Greenland

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-07-01

    GREENLAND—Tom Lane and Suk Joon Lee, recent graduates of Dartmouth University's Thayer School of Engineering, in Hanover, N. H., are standing outside in the frigid cold testing an autonomous robot that could help with scientific research and logistics in harsh polar environments. This summer, Lane, Lee, and others are at Summit Station, a U.S. National Science Foundation (NSF)-sponsored scientific research station in Greenland, fine-tuning a battery-powered Yeti robot as part of a team working on the NSF-funded Cool Robot project. The station, also known as Summit Camp, is located on the highest point of the Greenland Ice Sheet (72°N, 38°W, 3200 meters above sea level) near the middle of the island. It is a proving ground this season for putting the approximately 68-kilogram, 1-cubic-meter robot through its paces, including improving Yeti's mobility capabilities and field-testing the robot. (See the electronic supplement to this Eos issue for a video of Yeti in action (http://www.agu.org/eos_elec/).) During field-testing, plans call for the robot to collect data on elevation and snow surface characteristics, including accumulation. In addition, the robot will collect black carbon and elemental carbon particulate matter air samples around Summit Camp's power generator to help study carbon dispersion over snow.

  5. Toxaphene in the aquatic environment of Greenland.

    PubMed

    Vorkamp, Katrin; Rigét, Frank F; Dietz, Rune

    2015-05-01

    The octa- and nonachlorinated bornanes (toxaphene) CHBs 26, 40, 41, 44, 50 and 62 were analysed in Arctic char (Salvelinus alpinus), shorthorn sculpin (Myoxocephalus scorpius), ringed seal (Pusa hispida) and black guillemot eggs (Cepphus grylle) from Greenland. Despite their high trophic level, ringed seals had the lowest concentrations of these species, with a Σ6Toxaphene median concentration of 13-20 ng/g lipid weight (lw), suggesting metabolisation. The congener composition also suggests transformation of nona- to octachlorinated congeners. Black guillemot eggs had the highest concentrations (Σ6Toxaphene median concentration of 971 ng/g lw). Although concentrations were higher in East than in West Greenland differences were smaller than for other persistent organic pollutants. In a circumpolar context, toxaphene had the highest concentrations in the Canadian Arctic. Time trend analyses showed significant decreases for black guillemot eggs and juvenile ringed seals, with annual rates of -5 to -7% for Σ6Toxaphene. The decreases were generally steepest for CHBs 40, 41 and 44.

  6. Instrument for Analysis of Greenland's Glacier Mills

    NASA Technical Reports Server (NTRS)

    Behar, Alberto E.; Matthews, Jaret B.; Tran, Hung B.; Steffen, Konrad; McGrath, Dan; Phillips, Thomas; Elliot, Andrew; OHern, Sean; Lutz, Colin; Martin, Sujita; Wang, Henry

    2010-01-01

    A new instrument is used to study the inner workings of Greenland s glacier mills by riding the currents inside a glacier s moulin. The West Greenland Moulin Explorer instrument was deployed into a tubular shaft to autonomously record temperature, pressure, 3D acceleration, and location. It is built with a slightly positive buoyancy in order to assist in recovery. The unit is made up of several components. A 3-axis MEMS (microelectromechanical systems) accelerometer with 0.001-g resolution forms the base of the unit. A pressure transducer is added that is capable of withstanding 500 psi (=3.4 MPa), and surviving down to -40 C. An Iridium modem sends out data every 10 minutes. The location is traced by a GPS (Global Positioning System) unit. This GPS unit is also used for recovery after the mission. Power is provided by a high-capacity lithium thionyl chloride D-sized battery. The accelerometer is housed inside a cylindrical, foot-long (=30 cm) polyvinyl chloride (PVC) shell sealed at each end with acrylic. The pressure transducer is attached to one of these lids and a MEMS accelerometer to the other, recording 100 samples per second per axis.

  7. SIMPL/AVIRIS-NG Greenland 2015: Flight Report

    NASA Technical Reports Server (NTRS)

    Brunt, Kelly M.; Neumann, Thomas A.; Markus, Thorsten

    2015-01-01

    In August 2015, NASA conducted a two-­aircraft, coordinated campaign based out of Thule Air Base, Greenland, in support of Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) algorithm development. The survey targeted the Greenland Ice Sheet and sea ice in the Arctic Ocean during the summer melt season. The survey was conducted with a photon-counting laser altimeter in one aircraft and an imaging spectrometer in the second aircraft. Ultimately, the mission, SIMPL/AVIRIS-NG Greenland 2015, conducted nine coordinated science flights, for a total of 37 flight hours over the ice sheet and sea ice.

  8. Winter Camp: A Blog from the Greenland Summit, Part II

    NASA Technical Reports Server (NTRS)

    Koenig, Lora

    2009-01-01

    An earlier issue presents the first half of the author's experience living and working at the National Science Foundation's (NSF) Greenland Summit Camp. The author is a remote-sensing glaciologist at NASA s Goddard Space Flight Center. She took measurements that will be used to validate data collected by NASA s Aqua, Terra, and Ice, Clouds, and land Elevation Satellite (ICESat) satellites with ground-truth measurements of the Greenland Ice Sheet she made at Summit Camp from November 2008-February 2009. This article presents excerpts from the second half of her stay and work at the Greenland Summit.

  9. Influence of light and feeding conditions on swimming activity rhythms of larval and juvenile turbot. Scophthalmus maximus L.: An experimental study

    NASA Astrophysics Data System (ADS)

    Champalbert, Gisèle; Le Direach-Boursier, Laurence

    1998-12-01

    Turbot larvae are transported towards coastal nursery areas and live in very shallow waters. Food availability is assumed to be an important factor that retains them in such areas. To study the effects of a biotic factor (food) and an abiotic factor (light) that strongly influence behavioural mechanisms, experiments were carried out on laboratory-reared animals: larvae (1 cm), post-larvae (1.2 to 2.5 cm) and early juveniles (6 to 7 cm). Three kinds of apparatus and methods were used to record variations in swimming activity: (1) a phototaxis device to study orientation reactions in horizontal tanks; (2) actographs with infrared photoelectric barriers fitted around vertical cylindrical tanks; and (3) video cameras and cylindrical tanks. Observations were performed in total darkness and under dark-light regimes. Different types and quantities of food were provided to the fish. Larvae and juveniles of turbot exhibited a positive phototaxis from 1 to 1000 μW cm -2. At intensities lower than or equal to 0.1 μW cm -2, they did not exhibit clear reactions toward or away from the light. Turbot larvae and juveniles kept in total darkness did not show a clear rhythm of activity. Under natural illumination as well as in artificial LD conditions of similar periodicity, larvae swam by day and night. Live food ( Artemia nauplii or juvenile mysids) induced an immediate increase in activity or the maintenance of a high level of activity, which decreased over the following days. Recently metamorphosed turbot kept under LD conditions exhibited a clear rhythm with a nocturnal maximum. Food given at night did not induce swimming changes as long as food density remained low. At higher prey concentrations, increased activity during feeding was followed by reduced activity for more than 24 hours. A similar response pattern was noted when active food was given in large quantities during the day: juveniles displayed an immediate increase in activity, which subsequently decreased. Regular

  10. Modelling the present and future behaviour of the glaciers terminating into Godthåbsfjord, West Greenland

    NASA Astrophysics Data System (ADS)

    Fitzner, Antje; Dahl-Jensen, Dorthe

    2013-04-01

    The mass loss of the Greenland ice sheet is caused by changing surface mass balance, direct melting on the surface, ice flow through the numerous outlet glaciers, and basal melt. The largest outlet glaciers, like Jabobshavn Isbræ, are studied in great detail. However, processes leading to their behaviour such as calving and basal melting are not well understood. In this study, we focus on the fjord system, Godthåbsfjord, near Nuuk in West Greenland. Godthåbsfjord is a unique fjord with its length of about 300 km and a shallow sill at the fjord entrance that protects the fjord system. There are several tidewater glaciers terminating into the fjord contributing to the fresh water content in the fjord. The largest contributor is Kangiata Nunâta Sermia (KNS). Also, comprehensive oceanographic measurements in Godthåbsfjord are compared to link the ice sheet model to the fjord system. Here we aim to describe the present and future behaviour of KNS. The Parallel Ice Sheet Model (PISM), developed at the University of Alaska Fairbanks, is used for the regional modelling applied to the KNS drainage basin. Climatic forcing is provided by the Danish Meteorological Institute in form of HIRHAM5 ERA-Interim reanalysis model output covering the 1989 - 2011 period. PISM is able to show seasonal variability in the modelled fluxes when monthly means of the climatic forcing are applied. Observed surface velocities from InSAR and GPSs, ice thickness, and solid ice flux estimates at the terminus are used to determine the best parameter setting describing the present state of KNS. Those settings are then used for future projections (until 2050) to estimate solid ice flux and basal melt, that enters the fjord system as fresh water. This study is conducted in affiliation with the Greenland Climate Research Centre in Nuuk.

  11. Distribution of Alexandrium fundyense (Dinophyceae) cysts in Greenland and Iceland, with an emphasis on viability and growth in the Arctic

    PubMed Central

    Richlen, Mindy L.; Zielinski, Oliver; Holinde, Lars; Tillmann, Urban; Cembella, Allan; Lyu, Yihua; Anderson, Donald M.

    2016-01-01

    The bloom-forming dinoflagellate Alexandrium fundyense has been extensively studied due its toxin-producing capabilities and consequent impacts to human health and economies. This study investigated the prevalence of resting cysts of A. fundyense in western Greenland and Iceland to assess the historical presence and magnitude of bloom populations in the region, and to characterize environmental conditions during summer, when bloom development may occur. Analysis of sediments collected from these locations showed that Alexandrium cysts were present at low to moderate densities in most areas surveyed, with highest densities observed in western Iceland. Additionally, laboratory experiments were conducted on clonal cultures established from isolated cysts or vegetative cells from Greenland, Iceland, and the Chukchi Sea (near Alaska) to examine the effects of photoperiod interval and irradiance levels on growth. Growth rates in response to the experimental treatments varied among isolates, but were generally highest under conditions that included both the shortest photoperiod interval (16h:8h light:dark) and higher irradiance levels (~146–366 μmol photons m−2 s−1), followed by growth under an extended photoperiod interval and low irradiance level (~37 μmol photons m−2 s−1). Based on field and laboratory data, we hypothesize that blooms in Greenland are primarily derived from advected Alexandrium populations, as low bottom temperatures and limited light availability would likely preclude in situ bloom development. In contrast, the bays and fjords in Iceland may provide more favorable habitat for germling cell survival and growth, and therefore may support indigenous, self-seeding blooms. PMID:27721528

  12. Persistent organochlorine compounds in peregrine falcon (Falco peregrinus) eggs from South Greenland: levels and temporal changes between 1986 and 2003.

    PubMed

    Vorkamp, Katrin; Thomsen, Marianne; Møller, Søren; Falk, Knud; Sørensen, Peter B

    2009-02-01

    Thirty-seven addled peregrine falcon eggs collected in South Greenland between 1986 and 2003 were analysed for their content of the organochlorine compounds polychlorinated biphenyls (PCBs), dichlorodiphenyl tricloroethane (DDT) and its degradation products, hexachlorocyclohexane (HCH) isomers and hexachlorobenzene (HCB). PCBs and DDT (including metabolites) were by far the most abundant OC groups, with median concentrations of 55 and 40 microg/g lw, respectively. The concentrations were high in an Arctic context, but similar to previously reported levels from Alaska and Norway and slightly lower than concentrations measured in eggs from industrialised regions. Geographical differences may be of importance, considering the migration of peregrine falcons and their prey. SigmaHCH and HCB had median concentrations of 0.39 and 0.17 microg/g lw, respectively. On average, DDE accounted for 97% of SigmaDDT, but was below critical levels for eggshell thinning. All compound groups showed a weak decreasing trend over the study period, which was statistically significant for HCB and close to being significant for SigmaHCH. The weak decrease of SigmaPCB and SigmaDDT is different from other time trend studies from Greenland, usually showing a more pronounced decrease in the beginning of the study period, followed by a certain stabilisation in recent years. PMID:18823663

  13. Size and perspective in Alaska.

    PubMed

    Towle, Jim

    2006-01-01

    By far America's largest state, Alaska has only 350 members, so effective communication matters in overcoming distance. Alaska has led the way in direct reimbursement, diversity in leadership, member involvement, and a distinctive lifestyle for its practitioners. The tripartite structure of organized dentistry is crucial in building understanding the issues involved in providing oral health care to the members of this vast state. PMID:17585733

  14. Radiation Climatology of the Greenland Ice Sheet Derived from Greenland Climate Network Data

    NASA Technical Reports Server (NTRS)

    Steffen, Konrad; Box, Jason

    2003-01-01

    The magnitude of shortwave and longwave dative fluxes are critical to surface energy balance variations over the Greenland ice sheet, affecting many aspects of its climate, including melt rates, the nature of low-level temperature inversions, the katabatic wind regime and buoyant stability of the atmosphere. Nevertheless, reliable measurements of the radiative fluxes over the ice sheet are few in number, and have been of limited duration and areal distribution (e.g. Ambach, 1960; 1963, Konzelmann et al., 1994, Harding et al., 1995, Van den Broeke, 1996). Hourly GC-Net radiation flux measurements spanning 1995-2001 period have been used to produce a monthly dataset of surface radiation balance components. The measurements are distributed widely across Greenland and incorporate multiple sensors

  15. Crustal structure of the Central-Eastern Greenland: results from the TopoGreenland refraction profile

    NASA Astrophysics Data System (ADS)

    Shulgin, Alexey; Thybo, Hans

    2014-05-01

    Until present, seismic surveys have only been carried out offshore and near the coasts of Greenland, where the crustal structure is affected by oceanic break-up. We present the deep seismic structure of the crust of the interior of Greenland, based on the new and the only existing so far seismic refraction/wide-angle reflection profile. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass, made acquisition of geophysical data logistically complicated. The profile extends 310 km inland in E-W direction from the approximate edge of the stable ice cap near the Scoresby Sund across the center of the ice cap. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along the profile. Explosive charge sizes were 1 ton at the ends and ca. 500 kg along the profile, loaded with about 125 kg at 35-85 m depth in individual boreholes. Given that the data acquisition was affected by the thick ice sheet, we questioned the quality of seismic records in such experiment setup. We have developed an automatic routine to check the amplitudes and spectra of the selected seismic phases and to check the differences/challenges in making seismic experiments on ice and the effects of ice on data interpretation. Using tomographic inversion and forward ray tracing modelling we have obtained the two-dimensional velocity model down to a 50 km depth. The model shows a decrease of crustal thickness from 47 km below the centre of Greenland in the western part of the profile to 40 km in its eastern part. Relatively high lower crustal velocities (Vp 6.8 - 7.3 km/s) in the western part of the TopoGreenland profile may result from past collision tectonics or, alternatively, may be related to the speculated passage of the Iceland mantle plume. Comparison of our results

  16. Alaska Athabascan stellar astronomy

    NASA Astrophysics Data System (ADS)

    Cannon, Christopher M.

    Stellar astronomy is a fundamental component of Alaska Athabascan cultures that facilitates time-reckoning, navigation, weather forecasting, and cosmology. Evidence from the linguistic record suggests that a group of stars corresponding to the Big Dipper is the only widely attested constellation across the Northern Athabascan languages. However, instruction from expert Athabascan consultants shows that the correlation of these names with the Big Dipper is only partial. In Alaska Gwich'in, Ahtna, and Upper Tanana languages the Big Dipper is identified as one part of a much larger circumpolar humanoid constellation that spans more than 133 degrees across the sky. The Big Dipper is identified as a tail, while the other remaining asterisms within the humanoid constellation are named using other body part terms. The concept of a whole-sky humanoid constellation provides a single unifying system for mapping the night sky, and the reliance on body-part metaphors renders the system highly mnemonic. By recognizing one part of the constellation the stargazer is immediately able to identify the remaining parts based on an existing mental map of the human body. The circumpolar position of a whole-sky constellation yields a highly functional system that facilitates both navigation and time-reckoning in the subarctic. Northern Athabascan astronomy is not only much richer than previously described; it also provides evidence for a completely novel and previously undocumented way of conceptualizing the sky---one that is unique to the subarctic and uniquely adapted to northern cultures. The concept of a large humanoid constellation may be widespread across the entire subarctic and have great antiquity. In addition, the use of cognate body part terms describing asterisms within humanoid constellations is similarly found in Navajo, suggesting a common ancestor from which Northern and Southern Athabascan stellar naming strategies derived.

  17. Alaska Interagency Ecosystem Health Work Group

    USGS Publications Warehouse

    Shasby, Mark

    2009-01-01

    The Alaska Interagency Ecosystem Health Work Group is a community of practice that recognizes the interconnections between the health of ecosystems, wildlife, and humans and meets to facilitate the exchange of ideas, data, and research opportunities. Membership includes the Alaska Native Tribal Health Consortium, U.S. Geological Survey, Alaska Department of Environmental Conservation, Alaska Department of Health and Social Services, Centers for Disease Control and Prevention, U.S. Fish and Wildlife Service, Alaska Sea Life Center, U.S. Environmental Protection Agency, and Alaska Department of Fish and Game.

  18. Operation IceBridge Alaska

    NASA Astrophysics Data System (ADS)

    Larsen, C.

    2015-12-01

    The University of Alaska Fairbanks (UAF) has flown LiDAR missions for Operation IceBridge in Alaska each year since 2009, expanding upon UAF's airborne laser altimetry program which started in 1994. These observations show that Alaska's regional mass balance is -75+11/-16 Gt yr-1 (1994-2013) (Larsen et al., 2015). A surprising result is that the rate of surface mass loss observed on non-tidewater glaciers in Alaska is extremely high. At these rates, Alaska contributes ~1 mm to global sea level rise every 5 years. Given the present lack of adequate satellite resources, Operation IceBridge airborne surveys by UAF are the most effective and efficient method to monitor this region's impact on global sea level rise. Ice depth measurements using radar sounding have been part of these airborne surveys since 2012. Many of Alaska's tidewater glaciers are bedded significantly below sea level. The depth and extent of glacier beds below sea level are critical factors in the dynamics of tidewater retreat. Improved radar processing tools are being used to predict clutter using forward simulation. This is essential to properly sort out true bed returns, which are often masked or obscured by valley wall returns. This presentation will provide an overview of the program, highlighting recent findings and observations from the most recent campaigns, and focusing on techniques used for the extrapolation of surface elevation changes to regional mass balances.

  19. Otitis media in Greenland. Studies on historical, epidemiological, microbiological, and immunological aspects.

    PubMed

    Homøe, P

    2001-01-01

    This thesis describes the different aspects of otitis media (OM) in the population of Greenland viewed in a historical and modern clinical perspective. Chapter 1 outlines the addressed problems and aims while chapters 2 and 3 deal with historical studies and an evaluation of the present knowledge based on the literature. Physical anthropological studies, using skeletal samples of adult Eskimo crania from before and after the colonization of Greenland in 1721 and information about modern living Eskimos (Inuit), have shown that OM sequelae of the temporal bones were significantly less common in pre-colonization Eskimos and that the mean area size of the pneumatized cell system in the temporal bone was significantly larger in pre-colonization Eskimos. These findings indicated an increase in OM after the colonization most likely caused by the social, cultural, habitary, and dietary changes due to increased contact with the outside world. Historical reports after the colonization confirm a high prevalence of OM especially in children. Modern epidemiological studies from the 1960's to 1980's in the Arctic region of Alaska, Canada, and Greenland along with reports from visiting consultant otologists in Greenland almost uniformly mention prevalent OM problems in children as well as in adults. The aim was therefore to further describe the epidemiological pattern of the different OM disease entities (acute OM (AOM), chronic OM (COM), COM with suppuration (CSOM), secretory OM (SOM), and cholesteatoma) and investigate the potentially associated risk factors in especially Greenlandic children because these diseases are primarily established and problematical in childhood. Chapter 4 describes the definitions used in the thesis and chapter 5 describes the studies included. Section 5.1 describes a study of cholesteatoma in Greenlanders. The study revealed an almost similar incidence of hospital treated children with cholesteatoma (6.6 per 100,000) as seen in comparable studies

  20. The first glacier inventory for entire Greenland

    NASA Astrophysics Data System (ADS)

    Rastner, P.; Bolch, T.; Mölg, N.; Le Bris, R.; Paul, F.

    2012-04-01

    Detailed glacier data is becoming more and more important in the last decades to solve several research issues. One of the most prominent questions in this regard is the potential contribution of glaciers and icecaps (GIC) to global sea-level rise. Primarily, estimates are uncertain due to the globally still incomplete information about glacier location and size, as well as large uncertainties in future climate scenarios. Recent studies that calculate global sea-level rise from GIC have developed simplified approaches using information from glacier inventories or gridded data sets and a range of different global climate models and emission scenarios. However, for several strongly glacierized regions very rough assumptions about the ice distribution have to be made and an urgent demand for a globally complete glacier inventory is expressed. The GIC on Greenland are one of the regions with lacking information. Within the EU FP7 project ice2sea we mapped the GIC on Greenland using Landsat TM/ETM+ imagery acquired around the year 2000, along with an additional dataset in the North (DCW - Digital Chart of the World). A digital elevation model (DEM) with 90 m resolution (GIMP DEM) was used to derive drainage divides and henceforth topographic parameters for each entity. A major challenge in this regard is the application of a consistent strategy to separate the local GIC from the ice sheet. For this purpose we have defined different levels of connectivity (CL) of the local GIC with the ice sheet: CL0: Not connected. CL1: Connected but separable (either with drainage divides in the accumulation region or in touch only - and thus separable - in the ablation region). CL2: Connected but non-separable (the local GIC contribute to the flow of an ice sheet outlet in the ablation area). Up to now close to 12'000 GIC (only CL0 and CL1) with a total area of about 129'000 km2 have been mapped considering only entities larger than 0.1 km2. The area of the ice sheet itself is

  1. Permian of Norwegian-Greenland sea margins: future exploration target

    SciTech Connect

    Surlyk, F.; Hurst, J.M.; Piasecki, S.; Rolle, F.; Stemmerik, L.; Thomsen, E.; Wrang, P.

    1984-09-01

    Oil and gas exploration in the northern North Sea and the southern Norwegian shelf has mainy been concentrated on Jurassic and younger reservoirs with Late Jurassic black shale source rocks. New onshore investigations in Jameson Land, central East Greenland, suggest that the Permian of the Norwegian-Greenland Sea margins contains relatively thick sequences of potential oil source rocks interbedded with carbonate reefs. The East Greenland, Upper Permian marine basin is exposed over a length of 400 km (250 mi) from Jameson Land in the south to Wollaston Forland in the north, parallel with the continental margin. The Upper Permian black shale is relatively thick, widely distributed, has a high organic carbon content, and a favorable kerogen type. Consequently, the possibilities for a Permian play in the northern part of the Norwegian shelf and along parts of the Norwegian-Greenland Sea margins are worth evaluating.

  2. High export of dissolved silica from the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Meire, L.; Meire, P.; Struyf, E.; Krawczyk, D. W.; Arendt, K. E.; Yde, J. C.; Juul Pedersen, T.; Hopwood, M. J.; Rysgaard, S.; Meysman, F. J. R.

    2016-09-01

    Silica is an essential element for marine life and plays a key role in the biogeochemistry of the ocean. Glacial activity stimulates rock weathering, generating dissolved silica that is exported to coastal areas along with meltwater. The magnitude of the dissolved silica export from large glacial areas such as the Greenland Ice Sheet is presently poorly quantified and not accounted for in global budgets. Here we present data from two fjord systems adjacent to the Greenland Ice Sheet which reveal a large export of dissolved silica by glacial meltwater relative to other macronutrients. Upscaled to the entire Greenland Ice Sheet, the export of dissolved silica equals 22 ± 10 Gmol Si yr-1. When the silicate-rich meltwater mixes with upwelled deep water, either inside or outside Greenland's fjords, primary production takes place at increased silicate to nitrate ratios. This likely stimulates the growth of diatoms relative to other phytoplankton groups.

  3. Pathways of warm water to the Northeast Greenland outlet glaciers

    NASA Astrophysics Data System (ADS)

    Schaffer, Janin; Timmermann, Ralph; Kanzow, Torsten; Arndt, Jan Erik; Mayer, Christoph; Schauer, Ursula

    2015-04-01

    The ocean plays an important role in modulating the mass balance of the Greenland Ice Sheet by delivering heat to the marine-terminating outlet glaciers surrounding the Greenland coast. The warming and accumulation of Atlantic Water in the subpolar North Atlantic has been suggested to be a potential driver of the glaciers' retreat over the last decades. The shelf regions thus play a critical role for the transport of Atlantic Water towards the glaciers, but also for the transfer of freshwater towards the deep ocean. A key region for the mass balance of the Greenland Ice Sheet is the Northeast Greenland Ice Stream. This large ice stream drains the second-largest basin of the Greenland Ice Sheet and feeds three outlet glaciers. The largest one is Nioghalvfjerdsfjorden (79°N-Glacier) featuring an 80 km long floating ice tongue. Both the ocean circulation on the continental shelf off Northeast Greenland and the circulation in the cavity below the ice tongue are weakly constrained so far. In order to study the relevant processes of glacier-ocean interaction we combine observations and model work. Here we focus on historic and recent hydrographic observations and on the complex bathymetry in the Northeast Greenland shelf region, which is thought to steer the flux of warm Atlantic water onto the continental shelf and into the sub-ice cavity beneath the 79°N-Glacier. We present a new global topography data set, RTopo-2, which includes the most recent surveys on the Northeast Greenland continental shelf and provides a detailed bathymetry for all around Greenland. In addition, RTopo-2 contains ice and bedrock surface topographies for Greenland and Antarctica. Based on the updated ocean bathymetry and a variety of hydrographic observations we show the water mass distribution on the continental shelf off Northeast Greenland. These maps enable us to discuss possible supply pathways of warm modified Atlantic waters on the continental shelf and thus potential ways of heat

  4. Improving Student Achievement in Alaska. Alaska Goals 2000 Annual Report, 1997-98.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau.

    Alaska Goals 2000 is part of a coordinated, statewide effort to improve public education for all students in Alaska. In 1997-1998, 90% of Alaska's federal funding was used to fund grants to local school districts, and 10% was used to fund state-level activities through the Alaska Department of Education. During 1997-1998, curriculum frameworks and…

  5. Alaska GeoFORCE, A New Geologic Adventure in Alaska

    NASA Astrophysics Data System (ADS)

    Wartes, D.

    2011-12-01

    RAHI, the Rural Alaska Honors Institute is a statewide, six-week, summer college-preparatory bridge program at the University of Alaska Fairbanks for Alaska Native and rural high school juniors and seniors. A program of rigorous academic activity combines with social, cultural, and recreational activities. Students are purposely stretched beyond their comfort levels academically and socially to prepare for the big step from home or village to a large culturally western urban campus. This summer RAHI is launching a new program, GeoFORCE Alaska. This outreach initiative is designed to increase the number and diversity of students pursuing STEM degree programs and entering the future high-tech workforce. It uses Earth science as the hook because most kids get excited about dinosaurs, volcanoes and earthquakes, but it includes physics, chemistry, math, biology and other sciences. Students will be recruited, initially from the Arctic North Slope schools, in the 8th grade to begin the annual program of approximately 8 days, the summer before their 9th grade year and then remain in the program for all four years of high school. They must maintain a B or better grade average and participate in all GeoFORCE events. The carrot on the end of the stick is an exciting field event each summer. Over the four-year period, events will include trips to Fairbanks, Arizona, Oregon and the Appalachians. All trips are focused on Earth science and include a 100+ page guidebook, with tests every night culminating with a final exam. GeoFORCE Alaska is being launched by UAF in partnership with the University of Texas at Austin, which has had tremendous success with GeoFORCE Texas. GeoFORCE Alaska will be managed by UAF's long-standing Rural Alaska Honors Insitute (RAHI) that has been successfully providing intense STEM educational opportunities for Alaskan high school students for almost 30 years. The Texas program, with adjustments for differences in culture and environment, will be

  6. Arctic Warming, Greenland Melt and Moulins

    NASA Astrophysics Data System (ADS)

    Steffen, K.; Huff, R.; Behar, A.

    2007-12-01

    Air temperatures on the Greenland ice sheet have increased by 4 deg. C since 1991. The ice sheet melt area increased by 30% for the western part between 1979-2006, with record melt years in 1987, 1991, 1998, 2002, 2005, and possibly the most extreme melt year in 2007. The increasing trend in the total area of melting bare ice is unmistakable at 13% per year, significant at a probability of 0.99. Hence, the bare ice region, the wet snow region, and the equilibrium line altitude have moved further inland and resulting in increased melt water flux towards the coast. Warm and extended air temperatures are to blame for 1.5 m water equivalent surface reduction at the long-term equilibrium line altitude, 1100 m elevation at 70 deg. N during summer 2007. Increase in ice velocity in the ablation region and the concurrent increase in melt water suggests that water penetrates to great depth through moulins and cracks, lubricating the bottom of the ice sheet. New insight was gained of subsurface hydrologic channels and cavities using new instrumentation and a video system during the melt peak in August 2007. Volume and geometry of a 100 m deep moulin were mapped with a rotating laser, and photographs with digital cameras. Sub-glacial hydrologic channels were investigated and filmed using a tethered, autonomous system, several hundred meters into the ice. These new results will be discussed in view of the rapid increase in melt area and mass loss of the Greenland ice sheet due to increasing air temperatures.

  7. Alaska Native Education Study: A Statewide Study of Alaska Native Values and Opinions Regarding Education in Alaska.

    ERIC Educational Resources Information Center

    McDowell Group, Juneau, AK.

    This document contains four reports detailing a four-phase research project on Alaska Natives' attitudes and values toward education. A literature review examines the history of Native education in Alaska, issues in research on American Indian and Alaska Native education, dropout studies, student assessment, language and culture, learning styles,…

  8. Profile: American Indian/Alaska Native

    MedlinePlus

    ... million American Indians and Alaska Natives. Typically, this urban clientele has less accessibility to hospitals; health clinics ... IHS and tribal health programs. Studies on the urban American Indian and Alaska Native population have documented ...

  9. Malaspina Glacier, Alaska

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite covers an area of 55 by 40 kilometers (34 by 25 miles) over the southwest part of the Malaspina Glacier and Icy Bay in Alaska. The composite of infrared and visible bands results in the snow and ice appearing light blue, dense vegetation is yellow-orange and green, and less vegetated, gravelly areas are in orange. According to Dr. Dennis Trabant (U.S. Geological Survey, Fairbanks, Alaska), the Malaspina Glacier is thinning. Its terminal moraine protects it from contact with the open ocean; without the moraine, or if sea level rises sufficiently to reconnect the glacier with the ocean, the glacier would start calving and retreat significantly. ASTER data are being used to help monitor the size and movement of some 15,000 tidal and piedmont glaciers in Alaska. Evidence derived from ASTER and many other satellite and ground-based measurements suggests that only a few dozen Alaskan glaciers are advancing. The overwhelming majority of them are retreating.

    This ASTER image was acquired on June 8, 2001. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next six years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. science team leader; Bjorn Eng of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The Terra mission is part of NASA's Earth Science Enterprise, along-term research and

  10. Trends in Alaska's People and Economy.

    ERIC Educational Resources Information Center

    Leask, Linda; Killorin, Mary; Martin, Stephanie

    This booklet provides data on Alaska's population, economy, health, education, government, and natural resources, including specific information on Alaska Natives. Since 1960, Alaska's population has tripled and become more diverse, more stable, older, less likely to be male or married, and more concentrated. About 69 percent of the population…

  11. Role of Greenland meltwater in the changing Arctic

    NASA Astrophysics Data System (ADS)

    Dukhovskoy, Dmitry; Proshutinsky, Andrey; Timmermans, Mary-Louise; Myers, Paul; Platov, Gennady; Bamber, Jonathan; Curry, Beth; Somavilla, Raquel

    2016-04-01

    Observational data show that the Arctic ocean-ice-atmosphere system has been changing over the last two decades. Arctic change is manifest in the atypical behavior of the climate indices in the 21st century. Before the 2000s, these indices characterized the quasi-decadal variability of the Arctic climate related to different circulation regimes. Between 1948 and 1996, the Arctic atmospheric circulation alternated between anticyclonic circulation regimes and cyclonic circulation regimes with a period of 10-15 years. Since 1997, however, the Arctic has been dominated by an anticyclonic regime. Previous studies indicate that in the 20th century, freshwater and heat exchange between the Arctic Ocean and the sub-Arctic seas were self-regulated and their interactions were realized via quasi-decadal climate oscillations. What physical processes in the Arctic Ocean - sub-Arctic ocean-ice-atmosphere system are responsible for the observed changes in Arctic climate variability? The presented work is motivated by our hypothesis that in the 21st century, these quasi-decadal oscillations have been interrupted as a result of an additional freshwater source associated with Greenland Ice Sheet melt. Accelerating since the early 1990s, the Greenland Ice Sheet mass loss exerts a significant impact on thermohaline processes in the sub-Arctic seas. Surplus Greenland freshwater, the amount of which is about a third of the freshwater volume fluxed into the region during the 1970s Great Salinity Anomaly event, can spread and accumulate in the sub-Arctic seas influencing convective processes there. It is not clear, however, whether Greenland freshwater can propagate into the interior convective regions in the Labrador Sea and the Nordic Seas. In order to investigate the fate and pathways of Greenland freshwater in the sub-Arctic seas and to determine how and at what rate Greenland freshwater propagates into the convective regions, several numerical experiments using a passive tracer to

  12. Instrumentation for single-dish observations with The Greenland Telescope

    NASA Astrophysics Data System (ADS)

    Grimes, Paul K.; Asada, K.; Blundell, R.; Burgos, R.; Chang, H.-H.; Chen, M. T.; Goldie, D.; Groppi, C.; Han, C. C.; Ho, P. T. P.; Huang, Y. D.; Inoue, M.; Kubo, D.; Koch, P.; Leech, J.; de Lera Acedo, E.; Martin-Cocher, P.; Nishioka, H.; Nakamura, M.; Matsushita, S.; Paine, S. N.; Patel, N.; Raffin, P.; Snow, W.; Sridharan, T. K.; Srinivasan, R.; Thomas, C. N.; Tong, E.; Wang, M.-J.; Wheeler, C.; Withington, S.; Yassin, G.; Zeng, L.-Z.

    2014-07-01

    The Greenland Telescope project will deploy and operate a 12m sub-millimeter telescope at the highest point of the Greenland i e sheet. The Greenland Telescope project is a joint venture between the Smithsonian As- trophysical Observatory (SAO) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). In this paper we discuss the concepts, specifications, and science goals of the instruments being developed for single-dish observations with the Greenland Telescope, and the coupling optics required to couple both them and the mm-VLBI receivers to antenna. The project will outfit the ALMA North America prototype antenna for Arctic operations and deploy it to Summit Station,1 a NSF operated Arctic station at 3,100m above MSL on the Greenland I e Sheet. This site is exceptionally dry, and promises to be an excellent site for sub-millimeter astronomical observations. The main science goal of the Greenland Telescope is to carry out millimeter VLBI observations alongside other telescopes in Europe and the Americas, with the aim of resolving the event horizon of the super-massive black hole at the enter of M87. The Greenland Telescope will also be outfitted for single-dish observations from the millimeter-wave to Tera-hertz bands. In this paper we will discuss the proposed instruments that are currently in development for the Greenland Telescope - 350 GHz and 650 GHz heterodyne array receivers; 1.4 THz HEB array receivers and a W-band bolometric spectrometer. SAO is leading the development of two heterodyne array instruments for the Greenland Telescope, a 48- pixel, 325-375 GHz SIS array receiver, and a 4 pixel, 1.4 THz HEB array receiver. A key science goal for these instruments is the mapping of ortho and para H2D+ in old protostellar ores, as well as general mapping of CO and other transitions in molecular louds. An 8-pixel prototype module for the 350 GHz array is currently being built for laboratory and operational testing on the Greenland Telescope

  13. Levels and trends of radioactive contaminants in the Greenland environment.

    PubMed

    Dahlgaard, Henning; Eriksson, Mats; Nielsen, Sven P; Joensen, Hans Pauli

    2004-09-20

    Levels of radioactive contaminants in various Greenland environments have been assessed during 1999-2001. The source of 137Cs, 90Sr and (239,240)Pu in terrestrial and fresh water environments is mainly global fallout. In addition, the Chernobyl accident gave a small contribution of 137Cs. Reindeer and lamb contain the largest observed 137Cs concentrations in the terrestrial environment--up to 80 Bq kg(-1) fresh weight have been observed in reindeer. Due to special environmental conditions, 137Cs is transferred to landlocked Arctic char with extremely high efficiency in South Greenland leading to concentrations up to 100 Bq kg(-1) fresh weight. In these cases very long ecological half-lives are seen. Concentrations of 99Tc, 137Cs and 90Sr in seawater and in marine biota decrease in the order North-East Greenland and the coastal East Greenland current > South-West Greenland > Central West Greenland and North-West Greenland > Irmiger Sea-Faroe Islands. The general large-scale oceanic circulation combined with European coastal discharges and previous contamination of the Arctic Ocean causes this. As the same tendency is seen for the persistent organic pollutants (POPs) DDT and PCB in marine biota, it is suggested that long-distance oceanic transport by coastal currents is a significant pathway also for POPs in the Greenland marine environment. The peak 99Tc discharge from Sellafield 1994-1995 has only been slightly visible in the present survey year 2000. The concentrations are expected to increase in the future, especially in East Greenland. The Bylot Sound at the Thule Airbase (Pituffik) in North-West Greenland was contaminated with plutonium and enriched uranium in a weapons accident in 1968. Biological activity has mixed accident plutonium efficiently into the new sediments resulting in continued high surface sediment concentrations three decades after the accident. Transfer of plutonium to benthic biota is low--and lower than observed in the Irish Sea. This is

  14. Crustal Structure in Central-Eastern Greenland: TOPOGREENLAND Refraction Profile

    NASA Astrophysics Data System (ADS)

    Shulgin, A. A.; Thybo, H.

    2013-05-01

    We present the seismic structure in the interior of Greenland based on the first measurements by the seismic refraction/wide angle reflection method. Previous seismic surveys have only been carried out offshore and near the coast of Greenland, where the crustal structure is affected by oceanic break-up and may not be representative of the interior of the island. Acquisition of geophysical data onshore Greenland is logistically complicated by the presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The EW-trending profile extends 310 km inland from the approximate edge of the stable ice cap near Scoresby Sund across the centre of the ice cap. The planned extension of the profile by use of OBSs and air gun shooting in Scoresbysund Fjord to the east coast of Greenland was unfortunately cancelled, because navigation was prevented by ice drift. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along the profile. Explosive charge sizes were 1 ton at the ends and ca. 500 kg along the profile, loaded with about 100 kg at 35-85 m depth in individual boreholes. Two-dimensional velocity model based on forward ray tracing and tomography modelling shows a decrease of crustal thickness from 47 km below the centre of Greenland in the western part to 40 km in the eastern part of the profile. Earlier studies show that crustal thickness further decreases eastward to ca. 30 km below the fjord system, but details of the changes are unknown. Relatively high lower crustal velocities (Vp 6.8 - 7.3) in the western part of the TopoGreenland profile may indicate past collision tectonics or may be related or to the passage of the Iceland mantle plume. The origin of the pronounced circum-Atlantic mountain ranges in Norway and eastern Greenland, which have

  15. Alaska Pipeline Insulation

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Crude oil moving through the 800-mile Trans-Alaska Pipeline must be kept at a relatively high temperature, about 180 degrees Fahrenheit, to maintain the fluidity of the oil. In Arctic weather, that demands highly effective insulation. General Electric Co.'s Space Division, Valley Forge, Pennsylvania, provided it with a spinoff product called Therm-O-Trol. Shown being installed on the pipeline, Therm-O-Trol is a metal-bonded polyurethane foam especially formulated for Arctic insulation. A second GE spinoff product, Therm-O-Case, solved a related problem involved in bringing hot crude oil from 2,000-foot-deep wells to the surface without transferring oil heat to the surrounding permafrost soil; heat transfer could melt the frozen terrain and cause dislocations that might destroy expensive well casings. Therm-O-Case is a double-walled oil well casing with multi-layered insulation which provides an effective barrier to heat transfer. Therm-O-Trol and Therm-O-Case are members of a family of insulating products which stemmed from technology developed by GE Space Division in heat transferlthermal control work on Gemini, Apollo and other NASA programs.

  16. Alexander Archipelago, Southeastern Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    West of British Columbia, Canada, and south of the Yukon Territory, the southeastern coastline of Alaska trails off into the islands of the Alexander Archipelago. The area is rugged and contains many long, U-shaped, glaciated valleys, many of which terminate at tidewater. The Alexander Archipelago is home to Glacier Bay National Park. The large bay that has two forks on its northern end is Glacier Bay itself. The eastern fork is Muir inlet, into which runs the Muir glacier, named for the famous Scottish-born naturalist John Muir. Glacier Bay opens up into the Icy Strait. The large, solid white area to the west is Brady Icefield, which terminates at the southern end in Brady's Glacier. To locate more interesting features from Glacier Bay National Park, take a look at the park service map. As recently as two hundred years ago, a massive ice field extended into Icy Strait and filled the Glacier Bay. Since that time, the area has experienced rapid deglaciation, with many large glaciers retreating 40, 60, even 80 km. While temperatures have increased in the region, it is still unclear whether the rapid recession is part of the natural cycle of tidewater glaciers or is an indicator of longer-term climate change. For more on Glacier Bay and climate change, read an online paper by Dr. Dorothy Hall, a MODIS Associate Science Team Member. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  17. Alaska Energy Inventory Project: Consolidating Alaska's Energy Resources

    NASA Astrophysics Data System (ADS)

    Papp, K.; Clough, J.; Swenson, R.; Crimp, P.; Hanson, D.; Parker, P.

    2007-12-01

    Alaska has considerable energy resources distributed throughout the state including conventional oil, gas, and coal, and unconventional coalbed and shalebed methane, gas hydrates, geothermal, wind, hydro, and biomass. While much of the known large oil and gas resources are concentrated on the North Slope and in the Cook Inlet regions, the other potential sources of energy are dispersed across a varied landscape from frozen tundra to coastal settings. Despite the presence of these potential energy sources, rural Alaska is mostly dependent upon diesel fuel for both electrical power generation and space heating needs. At considerable cost, large quantities of diesel fuel are transported to more than 150 roadless communities by barge or airplane and stored in large bulk fuel tank farms for winter months when electricity and heat are at peak demands. Recent increases in the price of oil have severely impacted the price of energy throughout Alaska, and especially hard hit are rural communities and remote mines that are off the road system and isolated from integrated electrical power grids. Even though the state has significant conventional gas resources in restricted areas, few communities are located near enough to these resources to directly use natural gas to meet their energy needs. To address this problem, the Alaska Energy Inventory project will (1) inventory and compile all available Alaska energy resource data suitable for electrical power generation and space heating needs including natural gas, coal, coalbed and shalebed methane, gas hydrates, geothermal, wind, hydro, and biomass and (2) identify locations or regions where the most economic energy resource or combination of energy resources can be developed to meet local needs. This data will be accessible through a user-friendly web-based interactive map, based on the Alaska Department of Natural Resources, Land Records Information Section's (LRIS) Alaska Mapper, Google Earth, and Terrago Technologies' Geo

  18. Hypoosmoregulation of larvae of the turbot, Scophthalamus maximus: drinking and gut function in relation to environmental salinity.

    PubMed

    Brown, J A; Tytler, P

    1993-04-01

    Measurement of blood osmolarity of pre-metamorphic turbot larvae demonstrated that hypoosmoregulation is well established in larvae 6 days post-hatch (121 degree-days) and older. Blood osmolarity of 121-420 degree-day larvae reared in 100% seawater was significantly greater than blood osmolarity of larvae reared in 50% seawater. Hypoosmoregulation involved drinking, but instantaneous drinking rates of 340 degree-day larvae reared in 100% seawater were only slightly more than those of similarly aged larvae reared in 50% seawater. Adaptation to environmental salinity involved changes in gut water absorption; 65-74% water absorption occurred in larvae reared in seawater compared to 30-35% water absorption in larvae reared in 50% seawater. Gastrointestinal water absorption occurred prior to the rectum. In seawater this occurred alongside a decrease in gut fluid osmolarity but desalting was apparently less significant than in adult fish. Absolute water absorption by the gut of 340 degree-day larvae reared in seawater was about 2-fold that of larvae held in 50% seawater, while the osmotic gradient between internal body fluids and environmental media differed by 4-fold, which implies changes the in water permeability of skin and/or developing gills. PMID:24214447

  19. Postprandial nutrient-sensing and metabolic responses after partial dietary fishmeal replacement by soyabean meal in turbot (Scophthalmus maximus L.).

    PubMed

    Xu, Dandan; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei; Song, Fei

    2016-02-14

    In this study, we chose a carnivorous fish, turbot (Scophthalmus maximus L.), to examine its nutrient-sensing and metabolic responses after ingestion of diets with fishmeal (FM), or 45% of FM replaced by soyabean meal (34·6% dry diet) balanced with or without essential amino acids (EAA) to match the amino acid profile of FM diet for 30 d. After a 1-month feeding trial, fish growth, feed efficiency and nutrient retention were markedly reduced by soyabean meal-incorporated (SMI) diets. Compared with the FM diet, SMI led to a reduction of postprandial influx of free amino acids, hypoactivated target of rapamycin signalling and a hyperactivated amino acid response pathway after refeeding, a status associated with reduced protein synthesis, impaired postprandial glycolysis and lipogenesis. These differential effects were not ameliorated by matching an EAA profile of soyabean meal to that of the FM diet through dietary amino acid supplementation. Therefore, this study demonstrated that the FM diet and SMI diets led to distinct nutrient-sensing responses, which in turn modulated metabolism and determined the utilisation efficiency of diets. Our results provide a new molecular explanation for the role of nutrient sensing in the inferior performance of aquafeeds in which FM is replaced by soyabean meal.

  20. Morphological comparison between a selected fast-growing strain and the common cultured strain of turbot Scophthalmus maximus

    NASA Astrophysics Data System (ADS)

    Liang, Xingming; Ma, Aijun; Wang, Xin'an; Li, Juan; Huang, Zhihui; Shang, Xiaomei

    2012-07-01

    To evaluate the effect of genetic improvement of the turbot Scophthalmus maximus, we analyzed morphological differences between a fast-growing strain obtained by family selection and the common cultured strain, by principal component analysis, stepwise discriminant analysis, and t -tests. Although they clearly differed morphologically, plots of the principal components of the two strains partially overlapped. However, the difference between the strains was supported with very high precision by discriminant analysis. The t -tests revealed that 4 of the 13 morphological traits analyzed were highly significantly different ( P <0.01), 4 traits also differed significantly ( P <0.05), and the remainder did not differ significantly. The coefficients of difference of the 13 traits were all lower than the threshold value between subspecies (1.28). Together, the results indicate that a trend for segregation of characters from the common cultured strain have already appeared in the selected fast-growing strain but the degree of segregation have not risen to subspecies level.

  1. Growth, oxygen consumption and activity of juvenile turbot ( scophthalmus maximus L.) reared under different temperatures and photoperiods

    NASA Astrophysics Data System (ADS)

    Imsland, Albert K.; Folkvord, A.; Stefansson, S. O.

    Juvenile turbot (5-125 g) were reared under two experimental temperatures: 10°C and 16°C, and three experimental photoperiods: LDN (natural photoperiod), LD 16:8 (16 h light: 8 h darkness), LD24:0 (continuous light), to study effects of temperature and photoperiod on growth, activity and oxygen consumption. Growth was strongly affected by temperature and was higher at 16°C than at 10°C. Continuous light had a growth-promoting effect at 10°C from mid-December to late March, while at 16°C this effect was restricted to December and January. A seasonal change in the condition index was found. The groups reared in continuous light had higher condition indices in winter. The experimental groups held at 16°C had higher O 2 consumption than those at 10°C. The LD24:0 groups invariably had a higher overall O 2 consumption than did the LDN and LD16:8 groups, the differences being caused by reduced O 2 consumption in the latter groups during darkness. The LD24:0 groups displayed higher activity than the LDN groups, in which activity was very low at night.

  2. Postprandial nutrient-sensing and metabolic responses after partial dietary fishmeal replacement by soyabean meal in turbot (Scophthalmus maximus L.).

    PubMed

    Xu, Dandan; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei; Song, Fei

    2016-02-14

    In this study, we chose a carnivorous fish, turbot (Scophthalmus maximus L.), to examine its nutrient-sensing and metabolic responses after ingestion of diets with fishmeal (FM), or 45% of FM replaced by soyabean meal (34·6% dry diet) balanced with or without essential amino acids (EAA) to match the amino acid profile of FM diet for 30 d. After a 1-month feeding trial, fish growth, feed efficiency and nutrient retention were markedly reduced by soyabean meal-incorporated (SMI) diets. Compared with the FM diet, SMI led to a reduction of postprandial influx of free amino acids, hypoactivated target of rapamycin signalling and a hyperactivated amino acid response pathway after refeeding, a status associated with reduced protein synthesis, impaired postprandial glycolysis and lipogenesis. These differential effects were not ameliorated by matching an EAA profile of soyabean meal to that of the FM diet through dietary amino acid supplementation. Therefore, this study demonstrated that the FM diet and SMI diets led to distinct nutrient-sensing responses, which in turn modulated metabolism and determined the utilisation efficiency of diets. Our results provide a new molecular explanation for the role of nutrient sensing in the inferior performance of aquafeeds in which FM is replaced by soyabean meal. PMID:26586314

  3. How warm was Greenland during the last interglacial period?

    NASA Astrophysics Data System (ADS)

    Landais, Amaelle; Masson-Delmotte, Valérie; Capron, Emilie; Langebroek, Petra M.; Bakker, Pepijn; Stone, Emma J.; Merz, Niklaus; Raible, Christoph C.; Fischer, Hubertus; Orsi, Anaïs; Prié, Frédéric; Vinther, Bo; Dahl-Jensen, Dorthe

    2016-09-01

    The last interglacial period (LIG, ˜ 129-116 thousand years ago) provides the most recent case study of multimillennial polar warming above the preindustrial level and a response of the Greenland and Antarctic ice sheets to this warming, as well as a test bed for climate and ice sheet models. Past changes in Greenland ice sheet thickness and surface temperature during this period were recently derived from the North Greenland Eemian Ice Drilling (NEEM) ice core records, northwest Greenland. The NEEM paradox has emerged from an estimated large local warming above the preindustrial level (7.5 ± 1.8 °C at the deposition site 126 kyr ago without correction for any overall ice sheet altitude changes between the LIG and the preindustrial period) based on water isotopes, together with limited local ice thinning, suggesting more resilience of the real Greenland ice sheet than shown in some ice sheet models. Here, we provide an independent assessment of the average LIG Greenland surface warming using ice core air isotopic composition (δ15N) and relationships between accumulation rate and temperature. The LIG surface temperature at the upstream NEEM deposition site without ice sheet altitude correction is estimated to be warmer by +8.5 ± 2.5 °C compared to the preindustrial period. This temperature estimate is consistent with the 7.5 ± 1.8 °C warming initially determined from NEEM water isotopes but at the upper end of the preindustrial period to LIG temperature difference of +5.2 ± 2.3 °C obtained at the NGRIP (North Greenland Ice Core Project) site by the same method. Climate simulations performed with present-day ice sheet topography lead in general to a warming smaller than reconstructed, but sensitivity tests show that larger amplitudes (up to 5 °C) are produced in response to prescribed changes in sea ice extent and ice sheet topography.

  4. Late Pleistocene and Holocene tephrostratigraphy of interior Alaska and Yukon: Key beds and chronologies over the past 30,000 years

    NASA Astrophysics Data System (ADS)

    Davies, Lauren J.; Jensen, Britta J. L.; Froese, Duane G.; Wallace, Kristi L.

    2016-08-01

    The Aleutian Arc-Alaska Peninsula and Wrangell volcanic field are the main source areas for tephra deposits found across Alaska and northern Canada, and increasingly, tephra from these eruptions have been found further afield in North America, Greenland, and Europe. However, there have been no broad scale reviews of the Late Pleistocene and Holocene tephrostratigraphy for this region since the 1980s, and this lack of data is hindering progress in identifying these tephra both locally and regionally. To address this gap and the variable quality of associated geochemical and chronological data, we undertake a detailed review of the latest Pleistocene to Holocene tephra found in interior Alaska and Yukon. This paper discusses nineteen tephra that have distributions beyond southwest Alaska and that have the potential to become, or already are, important regional markers. This includes three 'modern' events from the 20th century, ten with limited data availability but potentially broad distributions, and six that are widely reported in interior Alaska and Yukon. Each tephra is assessed in terms of chronology, geochemistry and distribution, with new Bayesian age estimates and geochemical data when possible. This includes new major-element geochemical data for Crater Peak 1992, Redoubt 1989-90, and two andesitic tephra from St Michael Island (Tephra D), as well as revised age estimates for Dawson tephra, Oshetna, Hayes set H, Aniakchak CFE II, and the White River Ashes, northern and eastern lobes.

  5. Dietary β-glucan (MacroGard®) enhances survival of first feeding turbot (Scophthalmus maximus) larvae by altering immunity, metabolism and microbiota.

    PubMed

    Miest, Joanna J; Arndt, Carmen; Adamek, Mikolaj; Steinhagen, Dieter; Reusch, Thorsten B H

    2016-01-01

    Reflecting the natural biology of mass spawning fish aquaculture production of fish larvae is often hampered by high and unpredictable mortality rates. The present study aimed to enhance larval performance and immunity via the oral administration of an immunomodulator, β-glucan (MacroGard(®)) in turbot (Scophthalmus maximus). Rotifers (Brachionus plicatilis) were incubated with or without yeast β-1,3/1,6-glucan in form of MacroGard(®) at a concentration of 0.5 g/L. Rotifers were fed to first feeding turbot larvae once a day. From day 13 dph onwards all tanks were additionally fed untreated Artemia sp. nauplii (1 nauplius ml/L). Daily mortality was monitored and larvae were sampled at 11 and 24 dph for expression of 30 genes, microbiota analysis, trypsin activity and size measurements. Along with the feeding of β-glucan daily mortality was significantly reduced by ca. 15% and an alteration of the larval microbiota was observed. At 11 dph gene expression of trypsin and chymotrypsin was elevated in the MacroGard(®) fed fish, which resulted in heightened tryptic enzyme activity. No effect on genes encoding antioxidative proteins was observed, whilst the immune response was clearly modulated by β-glucan. At 11 dph complement component c3 was elevated whilst cytokines, antimicrobial peptides, toll like receptor 3 and heat shock protein 70 were not affected. At the later time point (24 dph) an anti-inflammatory effect in form of a down-regulation of hsp 70, tnf-α and il-1β was observed. We conclude that the administration of MacroGard(®) induced an immunomodulatory response and could be used as an effective measure to increase survival in rearing of turbot.

  6. Cloning and sequence analysis of a full-length cDNA of SmPP1cb encoding turbot protein phosphatase 1 beta catalytic subunit

    NASA Astrophysics Data System (ADS)

    Qi, Fei; Guo, Huarong; Wang, Jian

    2008-02-01

    Reversible protein phosphorylation, catalyzed by protein kinases and phosphatases, is an important and versatile mechanism by which eukaryotic cells regulate almost all the signaling processes. Protein phosphatase 1 (PP1) is the first and well-characterized member of the protein serine/threonine phosphatase family. In the present study, a full-length cDNA encoding the beta isoform of the catalytic subunit of protein phosphatase 1(PP1cb), was for the first time isolated and sequenced from the skin tissue of flatfish turbot Scophthalmus maximus, designated SmPP1cb, by the rapid amplification of cDNA ends (RACE) technique. The cDNA sequence of SmPP1cb we obtained contains a 984 bp open reading frame (ORF), flanked by a complete 39 bp 5' untranslated region and 462 bp 3' untranslated region. The ORF encodes a putative 327 amino acid protein, and the N-terminal section of this protein is highly acidic, Met-Ala-Glu-Gly-Glu-Leu-Asp-Val-Asp, a common feature for PP1 catalytic subunit but absent in protein phosphatase 2B (PP2B). And its calculated molecular mass is 37 193 Da and pI 5.8. Sequence analysis indicated that, SmPP1cb is extremely conserved in both amino acid and nucleotide acid levels compared with the PP1cb of other vertebrates and invertebrates, and its Kozak motif contained in the 5'UTR around ATG start codon is GXXAXXGXX ATGG, which is different from mammalian in two positions A-6 and G-3, indicating the possibility of different initiation of translation in turbot, and also the 3'UTR of SmPP1cb is highly diverse in the sequence similarity and length compared with other animals, especially zebrafish. The cloning and sequencing of SmPP1cb gene lays a good foundation for the future work on the biological functions of PP1 in the flatfish turbot.

  7. Effects of dietary glucose and dextrin on activity and gene expression of glucokinase and fructose-1,6-bisphosphatase in liver of turbot Scophthalmus maximus.

    PubMed

    Nie, Qin; Miao, Huijun; Miao, Shuyan; Zhou, Huihui; Zhang, Yanjiao; Zhang, Wenbing; Mai, Kangsen

    2015-06-01

    Glucokinase (GK) and fructose-1,6-bisphosphatase (FBPase) play crucial role in glucose metabolism. In the present study, the cDNA encoding GK and FBPase was cloned from the liver of turbot Scophthalmus maximus by rapid amplification of cDNA end technique. Effects of dietary glucose and dextrin on the activities and gene expressions of these two enzymes were also studied. Results showed that the full length of GK cDNA was 2226 bp, consisting of an open reading frame (ORF) of 1434 bp. The full-length cDNA coding FBPase was 1314 bp with a 1014 bp ORF encoding 337 amino acids. Analyses of gene expression of GK and FBPase were conducted in gill, liver, the whole intestine, the whole kidney, heart, the dorsal white muscle and brain. The highest expression of GK was found in liver, followed by muscle. The expression of FBPase was found higher in liver than heart and gill. Both hepatic GK activity and mRNA expression were highly induced in turbot after being fed with dietary carbohydrates (p < 0.05). However, the GK activity and mRNA expression in the group with dietary glucose did not significantly differ from those in the group with dietary dextrin (p > 0.05). Compared with the control group, there were no significant differences in FBPase activity and mRNA expression in the glucose as well as dextrin group (p > 0.05). The increased hepatic GK activity and gene expression indicated that the first step of glycolysis was activated in turbot by dietary carbohydrates.

  8. Dietary β-glucan (MacroGard®) enhances survival of first feeding turbot (Scophthalmus maximus) larvae by altering immunity, metabolism and microbiota.

    PubMed

    Miest, Joanna J; Arndt, Carmen; Adamek, Mikolaj; Steinhagen, Dieter; Reusch, Thorsten B H

    2016-01-01

    Reflecting the natural biology of mass spawning fish aquaculture production of fish larvae is often hampered by high and unpredictable mortality rates. The present study aimed to enhance larval performance and immunity via the oral administration of an immunomodulator, β-glucan (MacroGard(®)) in turbot (Scophthalmus maximus). Rotifers (Brachionus plicatilis) were incubated with or without yeast β-1,3/1,6-glucan in form of MacroGard(®) at a concentration of 0.5 g/L. Rotifers were fed to first feeding turbot larvae once a day. From day 13 dph onwards all tanks were additionally fed untreated Artemia sp. nauplii (1 nauplius ml/L). Daily mortality was monitored and larvae were sampled at 11 and 24 dph for expression of 30 genes, microbiota analysis, trypsin activity and size measurements. Along with the feeding of β-glucan daily mortality was significantly reduced by ca. 15% and an alteration of the larval microbiota was observed. At 11 dph gene expression of trypsin and chymotrypsin was elevated in the MacroGard(®) fed fish, which resulted in heightened tryptic enzyme activity. No effect on genes encoding antioxidative proteins was observed, whilst the immune response was clearly modulated by β-glucan. At 11 dph complement component c3 was elevated whilst cytokines, antimicrobial peptides, toll like receptor 3 and heat shock protein 70 were not affected. At the later time point (24 dph) an anti-inflammatory effect in form of a down-regulation of hsp 70, tnf-α and il-1β was observed. We conclude that the administration of MacroGard(®) induced an immunomodulatory response and could be used as an effective measure to increase survival in rearing of turbot. PMID:26564474

  9. Phaeobacter and Ruegeria species of the Roseobacter clade colonize separate niches in a Danish Turbot (Scophthalmus maximus)-rearing farm and antagonize Vibrio anguillarum under different growth conditions.

    PubMed

    Porsby, Cisse Hedegaard; Nielsen, Kristian Fog; Gram, Lone

    2008-12-01

    Members of the Roseobacter clade colonize a Spanish turbot larval unit, and one isolate (Phaeobacter strain 27-4) is capable of disease suppression in in vivo challenge trials. Here, we demonstrate that roseobacters with antagonistic activity against Vibrio anguillarum also colonize a Danish turbot larval farm that relies on a very different water source (the Danish fiord Limfjorden as opposed to the Galician Atlantic Ocean). Phylogenetic analyses based on 16S rRNA and gyrase B gene sequences revealed that different species colonized different niches in the larval unit. Phaeobacter inhibens- and Phaeobacter gallaeciensis-like strains were primarily found in the production sites, whereas strains identified as Ruegeria mobilis or Ruegeria pelagia were found only in the algal cultures. Phaeobacter spp. were more inhibitory against the general microbiota from the Danish turbot larval unit than were the Ruegeria spp. Phaeobacter spp. produced tropodithietic acid (TDA) and brown pigment and antagonized V. anguillarum when grown under shaking (200 rpm) and stagnant (0 rpm) conditions, whereas Ruegeria spp. behaved similarly to Phaeobacter strain 27-4 and expressed these three phenotypes only during stagnant growth. Both genera attached to an inert surface and grew in multicellular rosettes after stagnant growth, whereas shaking conditions led to single cells with low attachment capacity. Bacteria from the Roseobacter clade appear to be universal colonizers of marine larval rearing units, and since the Danish Phaeobacter spp. displayed antibacterial activity under a broader range of growth conditions than did Phaeobacter strain 27-4, these organisms may hold greater promise as fish probiotic organisms.

  10. Site-specific effects of 17β-estradiol in hornyhead turbot (Pleuronichthys verticalis) collected from a wastewater outfall and reference location

    PubMed Central

    Rempel-Hester, Mary Ann; Hong, Haizheng; Wang, Yinsheng; Deng, Xin; Armstrong, Jeff; Gully, Joe; Schlenk, Daniel

    2011-01-01

    Studies throughout the southern California bight have indicated persistent estrogenic activity in male hornyhead turbot (Pleuronichthys verticalis). Plasma 17β-estradiol (E2) concentrations correlated with gonadal DNA damage in fish collected near a wastewater treatment plant outfall, but not from fish collected at the reference location. When the same species was collected from the same reference location and treated with E2, no relationship between uptake and gonadal DNA damage was observed. To evaluate the site-specific effects of E2 in fish from a wastewater outfall and fish from a reference location, male hornyhead turbot from each location were exposed to 15 μg/L aqueous E2 in a time-course experiment, with fish sampled every 12 h for 48 h. Concentrations of E2 were measured in the aqueous exposure and in plasma from the fish. Vitellogenin (vtg) was also measured in the plasma, and 8-oxo-7,8-dihydro-2′-deoxyguanosine levels in male gonads were measured as an indicator of DNA damage. Untreated fish from the outfall had significantly lower E2 in the plasma relative to the untreated reference fish, and this trend was consistent at each time point in the E2-treated fish. Vtg was significantly induced after 36 h of exposure in fish from both sites and no significant differences were observed between the sites. A significant increase of oxidative DNA damage was observed in E2-treated fish from the outfall population and the damage was significantly correlated with plasma E2 concentrations only in fish from the outfall after 48 h. These results indicated that there were significant differences in E2 disposition and gonadal genotoxicity between the hornyhead turbot populations following exposure to E2, suggesting that fish at wastewater outfalls may be more sensitive to DNA damage, which may be temporally related to concentrations of E2 in plasma. PMID:19286174

  11. Alaska volcanoes guidebook for teachers

    USGS Publications Warehouse

    Adleman, Jennifer N.

    2011-01-01

    Alaska’s volcanoes, like its abundant glaciers, charismatic wildlife, and wild expanses inspire and ignite scientific curiosity and generate an ever-growing source of questions for students in Alaska and throughout the world. Alaska is home to more than 140 volcanoes, which have been active over the last 2 million years. About 90 of these volcanoes have been active within the last 10,000 years and more than 50 of these have been active since about 1700. The volcanoes in Alaska make up well over three-quarters of volcanoes in the United States that have erupted in the last 200 years. In fact, Alaska’s volcanoes erupt so frequently that it is almost guaranteed that an Alaskan will experience a volcanic eruption in his or her lifetime, and it is likely they will experience more than one. It is hard to imagine a better place for students to explore active volcanism and to understand volcanic hazards, phenomena, and global impacts. Previously developed teachers’ guidebooks with an emphasis on the volcanoes in Hawaii Volcanoes National Park (Mattox, 1994) and Mount Rainier National Park in the Cascade Range (Driedger and others, 2005) provide place-based resources and activities for use in other volcanic regions in the United States. Along the lines of this tradition, this guidebook serves to provide locally relevant and useful resources and activities for the exploration of numerous and truly unique volcanic landscapes in Alaska. This guidebook provides supplemental teaching materials to be used by Alaskan students who will be inspired to become educated and prepared for inevitable future volcanic activity in Alaska. The lessons and activities in this guidebook are meant to supplement and enhance existing science content already being taught in grade levels 6–12. Correlations with Alaska State Science Standards and Grade Level Expectations adopted by the Alaska State Department of Education and Early Development (2006) for grades six through eleven are listed at

  12. Variations in Alaska tidewater glacier frontal ablation, 1985-2013

    NASA Astrophysics Data System (ADS)

    McNabb, R. W.; Hock, R.; Huss, M.

    2015-01-01

    Our incomplete knowledge of the proportion of mass loss due to frontal ablation (the sum of ice loss through calving and submarine melt) from tidewater glaciers outside of the Greenland and Antarctic ice sheets has been cited as a major hindrance to accurate predictions of global sea level rise. We present a 28 year record (1985-2013) of frontal ablation for 27 Alaska tidewater glaciers (representing 96% of the total tidewater glacier area in the region), calculated from satellite-derived ice velocities and modeled estimates of glacier ice thickness. We account for cross-sectional ice thickness variation, long-term thickness changes, mass lost between an upstream fluxgate and the terminus, and mass change due to changes in terminus position. The total mean rate of frontal ablation for these 27 glaciers over the period 1985-2013 is 15.11 ± 3.63Gta-1. Two glaciers, Hubbard and Columbia, account for approximately 50% of these losses. The regional total ablation has decreased at a rate of 0.14Gta-1 over this time period, likely due to the slowing and thinning of many of the glaciers in the study area. Frontal ablation constitutes only ˜4% of the total annual regional ablation, but roughly 20% of net mass loss. Comparing several commonly used approximations in the calculation of frontal ablation, we find that neglecting cross-sectional thickness variations severely underestimates frontal ablation.

  13. Weathering along a periglacial stream, Western Greenland

    NASA Astrophysics Data System (ADS)

    Evans, M.; Beal, S.

    2009-12-01

    Chemical weathering of Ca-Mg silicate minerals followed by marine carbonate precipitation is the fundamental sink for atmospheric CO2 in the long-term carbon cycle. Weathering of silicates along the margins of large ice sheets has been implicated in reducing atmospheric CO2 and impacting global climate despite low temperatures and a lack of significant soil cover; conditions not traditionally considered conducive to high reaction rates. Most glacial weathering studies have focused on valley glacier settings, where high water flux and an abundance of clay to silt sized sediments speed the breakdown of silicate minerals. However, little is known about these processes in the marginal zones of the Greenland Ice Sheet (GIS), where recent warming and accelerated melt may lead to profound shifts in hydrology and biogeochemistry. Continued melting should increase water flux and eventually expose additional margin land-surface. It is unclear however if these changing conditions will lead to increased chemical denudation along the margin. An examination of the current weathering regime along the GIS margin is necessary to better constrain estimates of the impacts of changing conditions on future chemical weathering fluxes and related CO2 drawdown. Water, suspended load, and bedload samples were collected in July 2008 along a 6 km stretch of stream exiting the western side of the Greenland Ice Sheet. Waters and sediments were analyzed for major ions, alkalinity and Sr isotopes to determine the character and extent of weathering. Major ion concentrations in the stream waters are very low (0-45 μM HCO3- and 2-26 μM for individual salts) with significant dilution by superglacial ice melt. There are no systematic down-stream trends in ion concentrations. Silicate-derived ions make up most of the stream alkalinity indicating little to no carbonate weathering. K+ contributes up to 40% of the cation load and K+/Σcation ratios in streams far exceed those in bedload samples. This

  14. Teshekpuk Lake, Alaska

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This ASTER image of Teshekpuk Lake on Alaska's North Slope, within the National Petroleum Reserve, was acquired on August 15, 2000. It covers an area of 58.7 x 89.9 km, and is centered near 70.4 degrees north latitude, 153 degrees west longitude.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

    Size: 58.7 by 89.9 kilometers (36.4 by 55.7 miles) Location: 70.4 degrees North latitude, 153 degrees West longitude Orientation: North at top Image Data: ASTER Bands 3, 2, and 1 Original Data Resolution: ASTER 30 meters (98.4 feet) Dates Acquired: August 15, 2000

  15. Long term mass changes and interannual variability in the Canadian Archipelago and Gulf of Alaska from GRACE

    NASA Astrophysics Data System (ADS)

    Harig, C.; Simons, F. J.

    2015-12-01

    The mass transfer from land ice to the oceans is a major contributor to global sea-level rise. The glaciated regions of the Canadian Archipelago and the Gulf of Alaska are the next largest ice mass loss contributors outside of the Greenland and Antarctic ice sheets. Here we estimate the ice mass change of these regions since 2003 using time-variable gravity data from the GRACE mission. We employ an estimation technique based on spherical Slepian localization functions. These Slepian functions form a sparse set of orthogonal basis functions for a specific region and maximize the signal-to-noise levels of the gravity fields, making them excellent candidates to analyze regional data on the sphere.Between 2003 and 2012 Ellesmere Island lost mass (-38 Gt/yr) at an accelerating rate (-8 Gt/yr2), while Baffin Island lost mass at a lower rate (-22 Gt/yr) with very low acceleration. During this time, interannual variations were well described by an average seasonal cycle. Since 2013 ice mass in Ellesmere and Baffin islands, as well as Greenland, have diverged from their long term mass change trends. During the summer of 2013 these areas had the lowest recorded melt since the start of the GRACE mission. Through the end of 2014, the difference between the observed mass and the extrapolated long term trend for Greenland grew to over 500 gigatons. In contrast to the Canadian Archipelago, the Gulf of Alaska region has average seasonal mass variations four times larger per unit area and greater variability from year to year. Recent years of below average mass loss have lowered the average mass loss rate from previous estimates.

  16. Language Policy and Language Planning after the Establishment of the Home Rule in Greenland.

    ERIC Educational Resources Information Center

    Moller, Aquigssiaq

    1988-01-01

    Discusses the progress made and problems still surrounding Greenland's Home Rule Act which established the roles of Greenlandic and Danish in the instructional arena, covering attempts to make Greenlandic the native language while also encouraging bilingualism through mastery of Danish. (Author/CB)

  17. The United States National Climate Assessment - Alaska Technical Regional Report

    USGS Publications Warehouse

    Markon, Carl J.; Trainor, Sarah F.; Chapin, F. Stuart; Markon, Carl J.; Trainor, Sarah F.; Chapin, F. Stuart

    2012-01-01

    , because cold sea water absorbs CO2 more rapidly than warm water, and a decrease in sea ice extent has allowed increased sea surface exposure and more uptake of CO2 into these northern waters. Ocean acidification will likely affect the ability of organisms to produce and maintain shell material, such as aragonite or calcite (calcium carbonate minerals structured from carbonate ions), required by many shelled organism, from mollusks to corals to microscopic organisms at the base of the food chain. Direct biological effects in Alaska further along the food chain have yet to be studied and may vary among organisms. Some of the potentially most significant changes to Alaska that could result from a changing climate are the effects on the terrestrial cryosphere - particularly glaciers and permafrost. Alaskan glaciers are changing at a rapid rate, the primary driver appearing to be temperature. Statewide, glaciers lost 13 cubic miles of ice annually from the 1950s to the 1990s, and that rate doubled in the 2000s. However, like temperature and precipitation, glacier ice loss is not spatially uniform; most glaciers are losing mass, yet some are growing (for example Hubbard Glacier in southeast Alaska). Alaska glaciers with the most rapid loss are those terminating in sea water or lakes. With this increasing rate of melt, the contribution of surplus fresh water entering into the oceans from Alaska's glaciers, as well as those in neighboring British Columbia, Canada, is approximately 20 percent of that contributed by the Greenland Ice Sheet. Permafrost degradation (that is, the thawing of ice-rich soils) is currently (2012) impacting infrastructure and surface-water availability in areas of both discontinuous and continuous ground ice. Over most of the State, the permafrost is warming, with increasing temperatures broadly consistent with increasing air temperatures. On the Arctic coastal plain of Alaska, permafrost temperatures showed some cooling in the 1950s and 1960s but have

  18. Spatial variability of snow physical properties across northwestern Greenland

    NASA Astrophysics Data System (ADS)

    Courville, Z.; Polashenski, C.; Dibb, J. E.; Domine, F.

    2013-12-01

    In the late spring and early summer of 2013, researchers on the SAGE (Sunlight Absorption on the Greenland ice sheet Experiment) Traverse, embarked on a 4000 km ground traverse across northwestern Greenland in an attempt to quantify spatial variability of snow chemistry, snow physical properties, and snow reflectance. The field team targeted sites first visited by Carl Benson during his series of traverses from 1952 to 1955 as part of his pioneering work to characterize the Greenland Ice Sheet. This route now represents a rapidly changing and variable area of Greenland, as the route passes through several of the ice sheet facies first delimited by Benson. Along the traverse, the SAGE field team made ground-based albedo measurements using a hand-held spectroradiometer and collected snow physical property samples to determine snow specific surface area (SSA) from shallow, 2m pits. In addition, snow density and stratigraphy were measured. Snow layers in the near-surface and at the previous season's melt layer were targeted for sampling. Here we present preliminary snow physical property results from the upper portion of the snow pits and relate these to surface albedo data collected over the route. Further measurements of snow properties in the 2012 melt layer will be analyzed to assess the potential role of snow chemical (see Dibb et al. for a discussion of chemical analysis) and physical property driven albedo feedbacks could have played in contributing to that event. Route of 2013 SAGE Traverse in northwestern Greenland.

  19. How warm was Greenland during the last interglacial period?

    NASA Astrophysics Data System (ADS)

    Landais, Amaelle; Masson-Delmotte, Valérie; Capron, Emilie; Langenbroeck, Petra; Bakker, Pepijn; Stone, Emma; Fischer, Hubertus; Vinther, Bo; Dahl-Jensen, Dorthe

    2016-04-01

    The last interglacial period (LIG, ~129-116 thousand years ago) provides the most recent evidence for the response of Greenland and Antarctic ice sheets to polar warming above pre-industrial level, and a valuable test bed for ice sheet models. Key constraints on past changes in both ice sheet topography and surface temperature are derived from Greenland ice cores. The large warming estimated from the recent NEEM ice core drilled in northwest Greenland (8 ±4°C above pre-industrial) together with the evidence for limited local ice thinning have led to the "NEEM paradox", suggesting more stability of the ice sheet than simulated by ice flow models in response to such large warming. Here, we provide a new assessment of the LIG warming using ice core air isotopic composition (d15N) together with available relationships for Greenland between accumulation rate and temperature. The temperature at the upstream NEEM deposition site is estimated to be between -20°C to -24°C which is consistent with the 8±4°C warming relative to pre-industrial previously determined from water isotopic records measured on the NEEM ice, although we feel the lower end of this range to be more likely. Moreover, we show that under such warm temperature, melting of snow probably led to a significant firn shrinking by 15 m. We show that confirmation of this high temperature range for the LIG in Greenland is difficult to reconcile with climate modeling experiments

  20. Resolving bathymetry from airborne gravity along Greenland fjords

    USGS Publications Warehouse

    Boghosian, Alexandra; Tinto, Kirsty; Cochran, James R.; Porter, David; Elieff, Stefan; Burton, Bethany; Bell, Robin E.

    2015-01-01

    Recent glacier mass loss in Greenland has been attributed to encroaching warming waters, but knowledge of fjord bathymetry is required to investigate this mechanism. The bathymetry in many Greenland fjords is unmapped and difficult to measure. From 2010 to 2012, National Aeronautics and Space Administration's Operation IceBridge collected a unique set of airborne gravity, magnetic, radar, and lidar data along the major outlet glaciers and fjords in Greenland. We applied a consistent technique using the IceBridge gravity data to create 90 bathymetric profiles along 54 Greenland fjords. We also used this technique to recover subice topography where warm or crevassed ice prevents the radar system from imaging the bed. Here we discuss our methodology, basic assumptions and error analysis. We present the new bathymetry data and discuss observations in six major regions of Greenland covered by IceBridge. The gravity models provide a total of 1950 line kilometers of bathymetry, 875 line kilometers of subice topography, and 12 new grounding line depths.

  1. Exploring Greenland: science and technology in Cold War settings.

    PubMed

    Heymann, Matthias; Knudsen, Henrik; Lolck, Maiken L; Nielsen, Henry; Nielsen, Kristian H; Ries, Christopher J

    2010-01-01

    This paper explores a vacant spot in the Cold War history of science: the development of research activities in the physical environmental sciences and in nuclear science and technology in Greenland. In the post-war period, scientific exploration of the polar areas became a strategically important element in American and Soviet defence policy. Particularly geophysical fields like meteorology, geology, seismology, oceanography, and others profited greatly from military interest. While Denmark maintained formal sovereignty over Greenland, research activities were strongly dominated by U.S. military interests. This paper sets out to summarize the limited current state of knowledge about activities in the environmental physical sciences in Greenland and their entanglement with military, geopolitical, and colonial interests of both the USA and Denmark. We describe geophysical research in the Cold War in Greenland as a multidimensional colonial endeavour. In a period of decolonization after World War II, Greenland, being a Danish colony, became additionally colonized by the American military. Concurrently, in a period of emerging scientific internationalism, the U.S. military "colonized" geophysical research in the Arctic, which increasingly became subject to military directions, culture, and rules.

  2. Resolving bathymetry from airborne gravity along Greenland fjords

    NASA Astrophysics Data System (ADS)

    Boghosian, Alexandra; Tinto, Kirsty; Cochran, James R.; Porter, David; Elieff, Stefan; Burton, Bethany L.; Bell, Robin E.

    2015-12-01

    Recent glacier mass loss in Greenland has been attributed to encroaching warming waters, but knowledge of fjord bathymetry is required to investigate this mechanism. The bathymetry in many Greenland fjords is unmapped and difficult to measure. From 2010 to 2012, National Aeronautics and Space Administration's Operation IceBridge collected a unique set of airborne gravity, magnetic, radar, and lidar data along the major outlet glaciers and fjords in Greenland. We applied a consistent technique using the IceBridge gravity data to create 90 bathymetric profiles along 54 Greenland fjords. We also used this technique to recover subice topography where warm or crevassed ice prevents the radar system from imaging the bed. Here we discuss our methodology, basic assumptions and error analysis. We present the new bathymetry data and discuss observations in six major regions of Greenland covered by IceBridge. The gravity models provide a total of 1950 line kilometers of bathymetry, 875 line kilometers of subice topography, and 12 new grounding line depths.

  3. Exploring Greenland: science and technology in Cold War settings.

    PubMed

    Heymann, Matthias; Knudsen, Henrik; Lolck, Maiken L; Nielsen, Henry; Nielsen, Kristian H; Ries, Christopher J

    2010-01-01

    This paper explores a vacant spot in the Cold War history of science: the development of research activities in the physical environmental sciences and in nuclear science and technology in Greenland. In the post-war period, scientific exploration of the polar areas became a strategically important element in American and Soviet defence policy. Particularly geophysical fields like meteorology, geology, seismology, oceanography, and others profited greatly from military interest. While Denmark maintained formal sovereignty over Greenland, research activities were strongly dominated by U.S. military interests. This paper sets out to summarize the limited current state of knowledge about activities in the environmental physical sciences in Greenland and their entanglement with military, geopolitical, and colonial interests of both the USA and Denmark. We describe geophysical research in the Cold War in Greenland as a multidimensional colonial endeavour. In a period of decolonization after World War II, Greenland, being a Danish colony, became additionally colonized by the American military. Concurrently, in a period of emerging scientific internationalism, the U.S. military "colonized" geophysical research in the Arctic, which increasingly became subject to military directions, culture, and rules. PMID:22043659

  4. Early Tertiary marine fossils from northern Alaska: implications for Arctic Ocean paleogeography and faunal evolution.

    USGS Publications Warehouse

    Marincovich, L.; Brouwers, E.M.; Carter, L.D.

    1985-01-01

    Marine mollusks and ostracodes indicate a post-Danian Paleocene to early Eocene (Thanetian to Ypresian) age for a fauna from the Prince Creek Formation at Ocean Point, northern Alaska, that also contains genera characteristic of the Cretaceous and Neogene-Quaternary. The life-assocation of heterochronous taxa at Ocean Point resulted from an unusual paleogeographic setting, the nearly complete isolation of the Arctic Ocean from about the end of the Cretaceous until sometime in the Eocene, in which relict Cretaceous taxa survived into Tertiary time while endemic taxa evolved in situ; these later migrated to the northern mid- latitudes. Paleobiogeographic affinities of the Ocean Point assocation with mild temperate faunas of the London Basin (England), Denmark, and northern Germany indicate that a shallow, intermittent Paleocene seaway extended through the Norwegian-Greenland Sea to the North Sea Basin. Early Tertiary Arctic Ocean paleogeography deduced from faunal evidence agrees with that inferred from plate-tectonic reconstructions.-Authors

  5. Contaminants in two West Greenland caribou populations.

    PubMed

    Gamberg, Mary; Cuyler, Christine; Wang, Xiaowa

    2016-06-01

    Two caribou populations in West Greenland were sampled and the kidneys, liver and muscle analyzed for contaminants, including aluminum, arsenic, cadmium, copper, lead, mercury, selenium and zinc. Although close in proximity, the two populations are topographically separated by an ice cap, which creates different climates and vegetation types in each region. Contaminant levels reflected the differing diets of the two caribou populations. To the south in the wetter lichen-rich region, caribou had significantly more aluminum, arsenic, cadmium, lead, mercury, selenium and zinc, likely due to atmospheric deposition on lichens. To the north in the dry desert steppe where grasses predominate, caribou had higher levels of copper. Cows collected in late winter had significantly less hepatic copper, lead and mercury if pregnant, indicating placental transfer of these elements. Our results suggest that hepatic copper levels <200 μg g(-1) dry weight may result in copper depletion in pregnant cows and hepatic mercury concentrations above 0.5 μg g(-1) dry weight may negatively affect fertility in caribou cows. Hepatic mercury levels were negatively correlated with cow body weight, suggesting an adverse effect on body condition. Element concentrations found in tissues from these caribou are not considered to be of a health concern for those consuming this traditional food. PMID:26956180

  6. Permanent GPS and crustal deformation in Greenland

    NASA Astrophysics Data System (ADS)

    Khan, S. A.

    2003-12-01

    The National Survey and Cadastre - Denmark (KMS) is responsible for the geodetic definition of the reference network in Greenland. Permanent GPS plays an important role in the monitoring and maintenance of the geodetic network. Furthermore, KMS supports the international GPS infrastructure and research by supporting IGS. In October 1998 KMS has established a permanent GPS station THU2 at Thule Airbase. Besides THU2 the old permanent station THU1 is also running. The Thule stations are important because they are two of the few northernmost stations in the IGS network. THU2 has been operating since March 1999, and it is now a high quality and high performance station contributing to the IGS Low-Earth Orbiters (LEO) network. Besides the GPS stations in Thule, KMS is also running a permanent GPS station SCOB in Scoresbysund, which was established in August 1997, and in October 2001 a permanent station QAQ1 was established in Qaqortoq. This station is registered at IGS. Furthermore, University of Colorado operates the IGS station Kellyville near Kangerlussuaq and a station in Kulusuk. Using the BERNESE software, we have calculated daily baseline solutions between the GPS sites. The time series of the 3D crustal movements are analyzed due to post glacial rebound, plate tectonic and seasonal deformations (e.g. atmosphere loading). In addition, we have used the GIPSY OASIS II software to obtain similar time series. The results are compared with modeled estimates of the glacial rebound.

  7. Hydrocarbon prospects offshore southern West Greenland

    SciTech Connect

    Chalmers, J.A.; Dahl-Jensen, T.; Bate, K.J.; Whittaker, R.C. )

    1996-01-01

    Interpretation of regional seismic data acquired in the 1990s together with a re-appraisal of the wells drilled in the 1970s has lead to an appreciation that the southern West Greenland Basin is underexplored and may contain large quantities of hydrocarbons. The regional structure and stratigraphy of the basin has been worked out. An early phase of extension, probably in the Early Cretaceous, was followed by a thermal subsidence phase in the Late Cretaceous during which thick mudstones were deposited. Renewed extension and strike-slip faulting associated with the onset of sea-floor spreading in the Labrador Sea in the Early Tertiary lead to the formation of large structures capable of trapping large quantities of hydrocarbons. Flat spots have been identified in several prospects in the Fylla Structural Complex, which is presently open for licensing, and other large structural traps exist on the Kang[cflx a]miut Ridge and in the Ikermiut area. Stratigraphic traps exist in a large syn-rift fan of mid-Cretaceous age and in Lower Tertiary basin-floor fans. All of these after structures are found in an area with an [open quotes]open-door[close quotes] licensing policy.

  8. Hydrocarbon prospects offshore southern West Greenland

    SciTech Connect

    Chalmers, J.A.; Dahl-Jensen, T.; Bate, K.J.; Whittaker, R.C.

    1996-12-31

    Interpretation of regional seismic data acquired in the 1990s together with a re-appraisal of the wells drilled in the 1970s has lead to an appreciation that the southern West Greenland Basin is underexplored and may contain large quantities of hydrocarbons. The regional structure and stratigraphy of the basin has been worked out. An early phase of extension, probably in the Early Cretaceous, was followed by a thermal subsidence phase in the Late Cretaceous during which thick mudstones were deposited. Renewed extension and strike-slip faulting associated with the onset of sea-floor spreading in the Labrador Sea in the Early Tertiary lead to the formation of large structures capable of trapping large quantities of hydrocarbons. Flat spots have been identified in several prospects in the Fylla Structural Complex, which is presently open for licensing, and other large structural traps exist on the Kang{cflx a}miut Ridge and in the Ikermiut area. Stratigraphic traps exist in a large syn-rift fan of mid-Cretaceous age and in Lower Tertiary basin-floor fans. All of these after structures are found in an area with an {open_quotes}open-door{close_quotes} licensing policy.

  9. Distinct patterns of seasonal Greenland glacier velocity

    PubMed Central

    Moon, Twila; Joughin, Ian; Smith, Ben; van den Broeke, Michiel R; van de Berg, Willem Jan; Noël, Brice; Usher, Mika

    2014-01-01

    Predicting Greenland Ice Sheet mass loss due to ice dynamics requires a complete understanding of spatiotemporal velocity fluctuations and related control mechanisms. We present a 5 year record of seasonal velocity measurements for 55 marine-terminating glaciers distributed around the ice sheet margin, along with ice-front position and runoff data sets for each glacier. Among glaciers with substantial speed variations, we find three distinct seasonal velocity patterns. One pattern indicates relatively high glacier sensitivity to ice-front position. The other two patterns are more prevalent and appear to be meltwater controlled. These patterns reveal differences in which some subglacial systems likely transition seasonally from inefficient, distributed hydrologic networks to efficient, channelized drainage, while others do not. The difference may be determined by meltwater availability, which in some regions may be influenced by perennial firn aquifers. Our results highlight the need to understand subglacial meltwater availability on an ice sheet-wide scale to predict future dynamic changes. Key Points First multi-region seasonal velocity measurements show regional differences Seasonal velocity fluctuations on most glaciers appear meltwater controlled Seasonal development of efficient subglacial drainage geographically divided PMID:25821275

  10. Biology of the Greenland shark Somniosus microcephalus.

    PubMed

    MacNeil, M A; McMeans, B C; Hussey, N E; Vecsei, P; Svavarsson, J; Kovacs, K M; Lydersen, C; Treble, M A; Skomal, G B; Ramsey, M; Fisk, A T

    2012-04-01

    Greenland shark Somniosus microcephalus is a potentially important yet poorly studied cold-water species inhabiting the North Atlantic and Arctic Oceans. Broad-scale changes in the Arctic ecosystem as a consequence of climate change have led to increased attention on trophic dynamics and the role of potential apex predators such as S. microcephalus in the structure of Arctic marine food webs. Although Nordic and Inuit populations have caught S. microcephalus for centuries, the species is of limited commercial interest among modern industrial fisheries. Here, the limited historical information available on S. microcephalus occurrence and ecology is reviewed and new catch, biological and life-history information from the Arctic and North Atlantic Ocean region is provided. Given the considerable by-catch rates in high North Atlantic Ocean latitudes it is suggested that S. microcephalus is an abundant predator that plays an important, yet unrecognized, role in Arctic marine ecosystems. Slow growth and large pup sizes, however, may make S. microcephalus vulnerable to increased fishing pressure in a warming Arctic environment.

  11. Contaminants in two West Greenland caribou populations.

    PubMed

    Gamberg, Mary; Cuyler, Christine; Wang, Xiaowa

    2016-06-01

    Two caribou populations in West Greenland were sampled and the kidneys, liver and muscle analyzed for contaminants, including aluminum, arsenic, cadmium, copper, lead, mercury, selenium and zinc. Although close in proximity, the two populations are topographically separated by an ice cap, which creates different climates and vegetation types in each region. Contaminant levels reflected the differing diets of the two caribou populations. To the south in the wetter lichen-rich region, caribou had significantly more aluminum, arsenic, cadmium, lead, mercury, selenium and zinc, likely due to atmospheric deposition on lichens. To the north in the dry desert steppe where grasses predominate, caribou had higher levels of copper. Cows collected in late winter had significantly less hepatic copper, lead and mercury if pregnant, indicating placental transfer of these elements. Our results suggest that hepatic copper levels <200 μg g(-1) dry weight may result in copper depletion in pregnant cows and hepatic mercury concentrations above 0.5 μg g(-1) dry weight may negatively affect fertility in caribou cows. Hepatic mercury levels were negatively correlated with cow body weight, suggesting an adverse effect on body condition. Element concentrations found in tissues from these caribou are not considered to be of a health concern for those consuming this traditional food.

  12. Tuberculosis among Children in Alaska.

    ERIC Educational Resources Information Center

    Gessner, Bradford D.

    1997-01-01

    The incidence of tuberculosis among Alaskan children under 15 was more than twice the national rate, with Alaska Native children showing a much higher incidence. Children with household exposure to adults with active tuberculosis had a high risk of infection. About 22 percent of pediatric tuberculosis cases were identified through school…

  13. Tularemia in Alaska, 1938 - 2010

    PubMed Central

    2011-01-01

    Tularemia is a serious, potentially life threatening zoonotic disease. The causative agent, Francisella tularensis, is ubiquitous in the Northern hemisphere, including Alaska, where it was first isolated from a rabbit tick (Haemophysalis leporis-palustris) in 1938. Since then, F. tularensis has been isolated from wildlife and humans throughout the state. Serologic surveys have found measurable antibodies with prevalence ranging from < 1% to 50% and 4% to 18% for selected populations of wildlife species and humans, respectively. We reviewed and summarized known literature on tularemia surveillance in Alaska and summarized the epidemiological information on human cases reported to public health officials. Additionally, available F. tularensis isolates from Alaska were analyzed using canonical SNPs and a multi-locus variable-number tandem repeats (VNTR) analysis (MLVA) system. The results show that both F. t. tularensis and F. t. holarctica are present in Alaska and that subtype A.I, the most virulent type, is responsible for most recently reported human clinical cases in the state. PMID:22099502

  14. A Title I Refinement: Alaska.

    ERIC Educational Resources Information Center

    Hazelton, Alexander E.; And Others

    Through joint planning with a number of school districts and the Region X Title I Technical Assistance Center, and with the help of a Title I Refinement grant, Alaska has developed a system of data storage and retrieval using microcomputers that assists small school districts in the evaluation and reporting of their Title I programs. Although this…

  15. Adventures in the Alaska Economy.

    ERIC Educational Resources Information Center

    Jackstadt, Steve; Huskey, Lee

    This publication was developed to increase students' understanding of basic economic concepts and the historical development of Alaska's economy. Comics depict major historical events as they occurred, but specific characters are fictionalized. Each of nine episodes is accompanied by several pages of explanatory text, which enlarges on the episode…

  16. Tularemia in Alaska, 1938 - 2010.

    PubMed

    Hansen, Cristina M; Vogler, Amy J; Keim, Paul; Wagner, David M; Hueffer, Karsten

    2011-01-01

    Tularemia is a serious, potentially life threatening zoonotic disease. The causative agent, Francisella tularensis, is ubiquitous in the Northern hemisphere, including Alaska, where it was first isolated from a rabbit tick (Haemophysalis leporis-palustris) in 1938. Since then, F. tularensis has been isolated from wildlife and humans throughout the state. Serologic surveys have found measurable antibodies with prevalence ranging from < 1% to 50% and 4% to 18% for selected populations of wildlife species and humans, respectively. We reviewed and summarized known literature on tularemia surveillance in Alaska and summarized the epidemiological information on human cases reported to public health officials. Additionally, available F. tularensis isolates from Alaska were analyzed using canonical SNPs and a multi-locus variable-number tandem repeats (VNTR) analysis (MLVA) system. The results show that both F. t. tularensis and F. t. holarctica are present in Alaska and that subtype A.I, the most virulent type, is responsible for most recently reported human clinical cases in the state. PMID:22099502

  17. Gestational diabetes mellitus in Greenland: a national study of prevalence and testing efficacy

    PubMed Central

    Pedersen, Michael Lynge; Olesen, Jesper; Jørgensen, Marit Eika; Damm, Peter

    2016-01-01

    Background Within the last 20 years, the prevalence of gestational diabetes mellitus (GDM) has been reported to be increasing worldwide in correlation with ethnic and geographic variations. The actual prevalence of GDM throughout all of Greenland remains unknown. Objective The aim of this study was to estimate the prevalence of GDM among Greenlanders and non-Greenlanders living in Greenland and to estimate the efficacy of testing for GDM. Design This study was performed as an observational, cross-sectional study including all women with permanent address in Greenland who had given birth to a singleton during 2014. The prevalence of GDM was calculated as the proportion of all pregnant women tested with a 75-g 2-h glucose tolerance test who had a 2-h capillary whole-blood glucose value of 8.5 mmol/l or above. Testing efficacy was calculated as the proportion of women who fulfilled the testing criteria who were actually tested in Greenland in 2014. Results A total of 794 women (727 Greenlanders and 67 non-Greenlanders) were included in the study. The prevalence of GDM among tested women was 3.3% (confidence interval, CI: 0.9–5.6) among Greenlanders and 12.5% (CI: 0–25.7) among non-Greenlanders, corresponding, respectively, to 1.0% (CI: 0.3–1.3) and 4.5% (CI: 0–9.4) of all singleton pregnancies in Greenland in 2014. The overall testing efficacy was 69.0% among all eligible residents of Greenland and 85.1% among eligible residents in the capital city, Nuuk. Conclusion In conclusion, the prevalence of GDM seems quite low in Greenland. Although diagnostic testing activity has improved within the last 6 years, still around one-third of all pregnant women in all Greenland fulfilling the testing criteria were not tested. Universal testing for GDM may be needed to improve testing of GDM in Greenland. PMID:27562574

  18. Subglacial lake drainage detected beneath the Greenland ice sheet

    PubMed Central

    Palmer, Steven; McMillan, Malcolm; Morlighem, Mathieu

    2015-01-01

    The contribution of the Greenland ice sheet to sea-level rise has accelerated in recent decades. Subglacial lake drainage events can induce an ice sheet dynamic response—a process that has been observed in Antarctica, but not yet in Greenland, where the presence of subglacial lakes has only recently been discovered. Here we investigate the water flow paths from a subglacial lake, which drained beneath the Greenland ice sheet in 2011. Our observations suggest that the lake was fed by surface meltwater flowing down a nearby moulin, and that the draining water reached the ice margin via a subglacial tunnel. Interferometric synthetic aperture radar-derived measurements of ice surface motion acquired in 1995 suggest that a similar event may have occurred 16 years earlier, and we propose that, as the climate warms, increasing volumes of surface meltwater routed to the bed will cause such events to become more common in the future. PMID:26450175

  19. Observation and modeling of surface ozone over Greenland

    SciTech Connect

    Kiilsholm, I.S.; Mikkelsen, I.S.; Rasmussen, A.; Sorensen, J.H.

    1996-12-31

    DMI initiated continuous measurements of surface ozone concentration in Greenland during spring 1994 as apart of the ARCTOC project (ARCtic Tropospheric Ozone Chemistry). The ARCTOC project is partially financed by EU, and is coordinated by the Institute for Environmental Physics, University of Heidelberg. The objectives are to investigate the mechanism causing sudden arctic tropospheric ozone loss, spatial extent and possible consequences of the phenomenon. The observation sites in Greenland are Thule (76{degrees} 31{prime} N, 68{degrees} 50{prime} W), Sondre Stromfjord (67{degrees} 00{prime} N, 50{degrees} 48{prime}W) and Scoresbysund (70{degrees} 29{prime}N, 21{degrees} 58{prime} W). The instruments are photometric ozone analyzers. Preliminary results show that the air parcels with low ozone values have spent four days or more in the boundary layer and have recently passed the strait between Canada and Greenland.

  20. Deformation Studies of NEEM, Greenland Basal Folded Ice

    NASA Astrophysics Data System (ADS)

    Keegan, K.; Dahl-Jensen, D.; Montagnat, M.; Weikusat, I.

    2015-12-01

    Deep Greenland ice cores and airborne radio echo sounding (RES) images have recently revealed that basal ice flow of the Greenland Ice Sheet is very unstable. In many locations, a basal layer of disturbed ice is observed. At the NEEM, Greenland site this folding occurs at the boundary between the Eemian and glacial ice regimes, indicating that differences in physical properties of the ice play a role in the disturbance. Past work in metallurgy and ice suggests that impurity content controls grain evolution and therefore deformation. We hypothesize that the differences in ice flow seen deep in the NEEM ice core are controlled by differences in the impurity content of the ice layers. Here we present results of fabric, grain size, impurity content, and deformation studies from samples above and below this unstable boundary in the ice sheet.

  1. Greenland temperature response to climate forcing during the last deglaciation.

    PubMed

    Buizert, Christo; Gkinis, Vasileios; Severinghaus, Jeffrey P; He, Feng; Lecavalier, Benoit S; Kindler, Philippe; Leuenberger, Markus; Carlson, Anders E; Vinther, Bo; Masson-Delmotte, Valérie; White, James W C; Liu, Zhengyu; Otto-Bliesner, Bette; Brook, Edward J

    2014-09-01

    Greenland ice core water isotopic composition (δ(18)O) provides detailed evidence for abrupt climate changes but is by itself insufficient for quantitative reconstruction of past temperatures and their spatial patterns. We investigate Greenland temperature evolution during the last deglaciation using independent reconstructions from three ice cores and simulations with a coupled ocean-atmosphere climate model. Contrary to the traditional δ(18)O interpretation, the Younger Dryas period was 4.5° ± 2°C warmer than the Oldest Dryas, due to increased carbon dioxide forcing and summer insolation. The magnitude of abrupt temperature changes is larger in central Greenland (9° to 14°C) than in the northwest (5° to 9°C), fingerprinting a North Atlantic origin. Simulated changes in temperature seasonality closely track changes in the Atlantic overturning strength and support the hypothesis that abrupt climate change is mostly a winter phenomenon. PMID:25190795

  2. Greenland temperature response to climate forcing during the last deglaciation.

    PubMed

    Buizert, Christo; Gkinis, Vasileios; Severinghaus, Jeffrey P; He, Feng; Lecavalier, Benoit S; Kindler, Philippe; Leuenberger, Markus; Carlson, Anders E; Vinther, Bo; Masson-Delmotte, Valérie; White, James W C; Liu, Zhengyu; Otto-Bliesner, Bette; Brook, Edward J

    2014-09-01

    Greenland ice core water isotopic composition (δ(18)O) provides detailed evidence for abrupt climate changes but is by itself insufficient for quantitative reconstruction of past temperatures and their spatial patterns. We investigate Greenland temperature evolution during the last deglaciation using independent reconstructions from three ice cores and simulations with a coupled ocean-atmosphere climate model. Contrary to the traditional δ(18)O interpretation, the Younger Dryas period was 4.5° ± 2°C warmer than the Oldest Dryas, due to increased carbon dioxide forcing and summer insolation. The magnitude of abrupt temperature changes is larger in central Greenland (9° to 14°C) than in the northwest (5° to 9°C), fingerprinting a North Atlantic origin. Simulated changes in temperature seasonality closely track changes in the Atlantic overturning strength and support the hypothesis that abrupt climate change is mostly a winter phenomenon.

  3. Y-chromosome STR haplotypes in males from Greenland.

    PubMed

    Hallenberg, Charlotte; Tomas, Carmen; Simonsen, Bo; Morling, Niels

    2009-09-01

    A total of 272 males from Greenland were typed for 11 Y-chromosome STRs DYS19, DYS385a/b, DYS389-I, DYS389-II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439 with the PowerPlex Y System (Promega). A total of 146 different haplotypes were observed and the haplotype diversity was 0.9887. The number of haplotypes seen once was 108 and the most common haplotype was observed in 12 males. A significant F(ST) value was observed (F(ST)=0.012, P<0.00001) when comparing the population of 15 locations in Greenland assigned to 7 groups. The significance could mainly be attributed to the subpopulation of males from Tasiilaq (East of Greenland). The R(ST) value was not statistically significant (R(ST)=0.016, P=0.15). PMID:19647703

  4. Paleofluvial mega-canyon beneath the central Greenland ice sheet.

    PubMed

    Bamber, Jonathan L; Siegert, Martin J; Griggs, Jennifer A; Marshall, Shawn J; Spada, Giorgio

    2013-08-30

    Subglacial topography plays an important role in modulating the distribution and flow of basal water. Where topography predates ice sheet inception, it can also reveal insights into former tectonic and geomorphological processes. Although such associations are known in Antarctica, little consideration has been given to them in Greenland, partly because much of the ice sheet bed is thought to be relatively flat and smooth. Here, we present evidence from ice-penetrating radar data for a 750-km-long subglacial canyon in northern Greenland that is likely to have influenced basal water flow from the ice sheet interior to the margin. We suggest that the mega-canyon predates ice sheet inception and will have influenced basal hydrology in Greenland over past glacial cycles. PMID:23990558

  5. Paleofluvial mega-canyon beneath the central Greenland ice sheet.

    PubMed

    Bamber, Jonathan L; Siegert, Martin J; Griggs, Jennifer A; Marshall, Shawn J; Spada, Giorgio

    2013-08-30

    Subglacial topography plays an important role in modulating the distribution and flow of basal water. Where topography predates ice sheet inception, it can also reveal insights into former tectonic and geomorphological processes. Although such associations are known in Antarctica, little consideration has been given to them in Greenland, partly because much of the ice sheet bed is thought to be relatively flat and smooth. Here, we present evidence from ice-penetrating radar data for a 750-km-long subglacial canyon in northern Greenland that is likely to have influenced basal water flow from the ice sheet interior to the margin. We suggest that the mega-canyon predates ice sheet inception and will have influenced basal hydrology in Greenland over past glacial cycles.

  6. Alcohol in Greenland 1951–2010: consumption, mortality, prices

    PubMed Central

    Aage, Hans

    2012-01-01

    Background Fluctuations in alcohol consumption in Greenland have been extreme since alcohol became available to the Greenland Inuit in the 1950s, increasing from low levels in the 1950s to very high levels in the 1980s – about twice as high as alcohol consumption in Denmark. Since then, consumption has declined, and current consumption is slightly below alcohol consumption in Denmark, while alcohol prices are far above Danish prices. Objective Description of historical trends and possible causal connections of alcohol prices, alcohol consumption and alcohol-related mortality in Greenland 1951–2010 as a background for the evaluation of the impact of various types of policy. Design Time series for Greenland 1951–2010 for alcohol prices, consumption and mortality are compiled, and variation and correlations are discussed in relation to various policies aimed at limiting alcohol consumption. Corresponding time series for Denmark 1906–2010 are presented for comparison. Results The trends in alcohol prices and consumption followed each other rather closely until the 1990s in Greenland and the 1980s in Denmark. At this time, consumption stabilised while prices decreased further, but the effect of prices upon consumption is strong, also in recent years. A trend in Greenlandic mortality similar to consumption is discernible, but not significant. Among alcohol-related deaths cirrhosis of the liver is less prevalent whilst accidents are more prevalent than in Denmark. Conclusions The effect of alcohol excise taxes and rationing upon consumption is evident. The stabilisation and subsequent decline in consumption since the mid-1990s, while alcohol prices decreased persistently, does not preclude continued effects of prices. On the contrary, price effects have been neutralised by other stronger causes. Whether these are government anti-alcohol campaigns or a cultural change is not clear. PMID:23256091

  7. Processes affecting the CO2 concentrations measured in Greenland ice

    NASA Astrophysics Data System (ADS)

    Anklin, Martin; Barnola, Jean-Marc; Schwander, Jakob; Stauffer, Bernhard; Raynaud, Dominique

    1995-09-01

    Detailed CO2 measurements on ice cores from Greenland and Antarctica show different mean CO2 concentrations for samples at the same gas age. The deviation between Antarctic and Greenland CO2 records raises up to 20 ppmv during the last millennium. Based on the present knowledge of the global carbon cycle we can exclude such a high mean interhemispheric difference of the CO2 concentration between high northern and southern latitudes. Diffusive mixing of the air in the firn smoothes out short term variations of the atmospheric CO2 Concentration. Nevertheless, we observe short term CO2 variations in Greenland ice in the range of 10 20 ppmv, which cannot represent atmospheric CO2 variations. Due to the low temperature at Summit, meltlayers can be excluded for most of the ice and they cannot account for the frequent anomalous short term CO2 variations and the elevated mean CO2 concentration in the Greenland ice. In this work we give some clues, that in situ production of CO2 in Greenland ice could build up excess CO2 after pore close of. Possible chemical reactions are the oxidation of organic carbon and the reaction between acidity and carbonate. We conclude that the carbonate-acidity reaction is the most probable process to explain the excess CO2 in the bubbles. The reaction could take place in very small liquid-like veins in cold ice, where the mobility of impurities is higher than in the ice lattice. At present, there exists no technique to measure the carbonate concentration in the ice directly. However, a comparison of CO2 analyses performed with a dry- and a wet-extraction technique allows to estimate the carbonate content of the ice. This estimate indicates a carbonate concentration in Greenland ice of about 0.4±0.2µmol/l and a much lower concentration in Antarctic ice.

  8. Acoustic mapping of the Ilulissat Ice Fjord mouth, West Greenland

    NASA Astrophysics Data System (ADS)

    Schumann, Kai; Völker, David; Weinrebe, Wilhelm R.

    2012-04-01

    A ship-based acoustic mapping campaign was conducted at the exit of Ilulissat Ice Fjord of West Greenland and in the sedimentary basin of Disko Bay west of the fjord mouth. Submarine landscape and sediment distribution patterns represented by five acoustic facies types represent glaciomarine sediment facies types that are related to variations in the past position and relative motion of the glacier front. Asymmetric ridges on the shelf that form a curved entity and a large sill at the fjord mouth represent moraines that depict at least two relatively stable positions of the ice front in the Disko Bay and at the fjord mouth. Comparable ice-end features are not observed seaward of the East Greenland Kangerdlugssuaq Glacier, although both glaciers are comparable in their latitudinal position, present size and present role for the ice discharge from the Inland Ice sheet. Apparently, the retreat of the Greenland Inland Ice after the last maximum expansion was a more discontinuous process on the West Greenland Shelf than on the East Greenland Shelf. The Iceberg Bank, a prominent sill at the fjord exit appears to play an important role for the sedimentation after the retreat of the ice front from the shelf was completed. The retreat of the glacier behind the Iceberg Bank into the inner fjord is marked by a reorganization of sediment delivery in Disko Bay, as most of the till is now deposited within the fjord. Two linear clusters of pockmarks in the center of the sedimentary basin seem to be linked to methane release due to dissociation of gas hydrates, a process driven by fast crustal uplift of the Greenland Shelf. The orientation of these clusters appears to reflect a migration path that is defined by a buried structure which we could not resolve.

  9. Leakage of the Greenland Ice Sheet through accelerated ice flow

    NASA Astrophysics Data System (ADS)

    Rignot, E.

    2005-12-01

    A map of coastal velocities of the Greenland ice sheet was produced from Radarsat-1 acquired during the background mission of 2000 and combined with radio echo sounding data to estimate the ice discharge from the ice sheet. On individual glaciers, ice discharge was compared with snow input from the interior and melt above the flux gate to determine the glacier mass balance. Time series of velocities on several glaciers at different latitudes reveal seasonal fluctuations of only 7-8 percent so that winter velocities are only 2 percent less than the yearly mean. The results show the northern Greenland glaciers to be close to balance yet losing mass. No change in ice flow is detected on Petermann, 79north and Zachariae Isstrom in 2000-2004. East Greenland glaciers are in balance and flowing steadily north of Kangerdlussuaq, but Kangerdlussuaq, Helheim and all the southeastern glaciers are thinning dramatically. All these glaciers accelerated, Kangerdlussuaq in 2000, Helheim prior to 2004, and southeast Greenland glaciers accelerated 10 to 50 percent in 2000-2004. Glacier acceleration is generally brutal, probably once the glacier reached a threshold, and sustained. In the northwest, most glaciers are largely out of balance. Jakobshavn accelerated significantly in 2002, and glaciers in its immediate vicinity accelerated more than 50 percent in 2000-2004. Less is known about southwest Greenland glaciers due to a lack of ice thickness data but the glaciers have accelerated there as well and are likely to be strongly out of balance despite thickening of the interior. Overall, I estimate the mass balance of the Greenland ice sheet to be about -80 +/-10 cubic km of ice per year in 2000 and -110 +/-15 cubic km of ice per year in 2004, i.e. more negative than based on partial altimetry surveys of the outlet glaciers. As climate continues to warm, more glaciers will accelerate, and the mass balance will become increasingly negative, regardless of the evolution of the ice sheet

  10. Tumour necrosis factor-α inhibits hepatic lipid deposition through GSK-3β/β-catenin signaling in juvenile turbot (Scophthalmus maximus L.).

    PubMed

    Liu, Dongwu; Mai, Kangsen; Zhang, Yanjiao; Xu, Wei; Ai, Qinghui

    2016-03-01

    In this study, the mechanism that TNFα inhibits lipid deposition through GSK-3β/β-catenin signaling was investigated in the liver of juvenile turbot (Scophthalmus maximus L.) by injection of TNFα or TNFα inhibitor pomalidomide (POM). It was found that TNFα inhibited the expression of GSK-3β and induced β-catenin expression. TNFα inhibited the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα), as well as the activity of lipoprotein lipase (LPL) and fatty acid synthetase (FAS). In addition, the level of triglyceride (TG), total cholesterol (TC), nonesterified fatty acid (NEFA), and glycerol was decreased by TNFα treatment in the liver. In the plasma, the level of TG, TC, low density lipoprotein cholesterol (LDL-C), NEFA, and glycerol was decreased, but high density lipoprotein cholesterol (HDL-C) was increased by TNFα treatment. However, compared to TNFα, POM had the opposite effect on the biochemical indexes and genes related to lipid deposition in the liver. The results indicated that TNFα may regulate hepatic lipid metabolism and fat distribution through GSK-3β/β-catenin signaling as well as transcription factors PPARγ and C/EBPα in juvenile turbot. PMID:26747182

  11. Effects of temperature, pH and NaCl on protease activity in digestive tract of young turbot, Scophthalmus maximus

    NASA Astrophysics Data System (ADS)

    Chen, Muyan; Zhang, Xiumei; Gao, Tianxiang; Chen, Chao

    2006-09-01

    The protease activity in digestive tract of young turbot Scophthalmus maximum was studied, and the optimal pH, temperature and NaCl concentration were determined for different portions of the fish's internal organs. The optimal activity in the fish's stomach was at pH of 2.2, while that in the intestinal extracts was within the alkaline range from 9.5 to 10.0. In hepatopancreas, the optimal pH was in low alkalinity at 8.5. The optimal reaction temperature was above 40°C in stomach, intestine and hepatopancreas. With increasing temperature, the pH value increased in stomach, while in the intestine, an opposite tendency was observed due to combined effect of pH and temperature. NaCl concentration showed inhibitory impact on protein digestion in hepatopancreas. The main protease for protein digestion in turbot seemed to be pepsin. Moreover, the maximum protease activity in different segments of intestine existed in the hindgut.

  12. [Biochemical, physicochemical and functional characterization of turbot (Scophthalmus maximus). Study of the changes occurring during the 4 degrees C storage].

    PubMed

    Abugoch, Lilian; Tapia, Cristian; Aravena, María Elena; López, Luis; Ramírez, Alberto; Oyarzo, Manuel

    2011-06-01

    The turbot (Scophthalmus maximus) is a kind of flatfish that is well adapted to intensive farm culture. After the harvest it is necessary to know the physicochemical, biochemical and technological properties and if during the refrigerated storage, changes of these properties are developed. The main objective of the study was the assessment of the proximal composition, the biochemical, physicochemical and functional properties, and how they are influenced during the 16 days storage at 4 degrees C. Parameters such as centesimal composition, PAGE-SDS, and protein thermal stability through a DSC were carried out. pH, total volatile base-nitrogen (TVB-N) dripping, texture, holding water capacity (WHC), emulsification (EC) and gelification (GC) were also determined. Results for the proximal composition were: humidity 76.3%; fat content 2.71%; proteins 19.6%; and ashes 1.3%. Two different thermal transitions at 47.5 degrees C (myosin) and 76.9 degrees C (actin) were observed. The PAGE-SDS showed profiles corresponding to myofibrilars and sarcoplasmatic proteins, which presented no changes during the storage. pH experimented an increase from 5.9 to 6.6; TVB-N showed a variation from 20.0 to 39.5 mg TVB-N/100 g of muscle at the day 16. The WHC started with a 10.5% and ended in 58.1%; no GC was observed. The increase of the EC and WHC during the storage was due to conformational changes of proteins. The compression force presented a fluctuation between 111.2 and 106.0 N and the shear strain decreased during the storage from 148.6 to 95.2 N. The dripping showed a variation between 1.7% and 2.5%. According to the results of the storage during 16 days at 4 degrees C, the NBV-T content determined a shelf life of 14 days. PMID:22308947

  13. Expression pattern of peptide and amino acid genes in digestive tract of transporter juvenile turbot ( Scophthalmus maximus L.)

    NASA Astrophysics Data System (ADS)

    Xu, Dandan; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei; Song, Fei

    2016-04-01

    Turbot ( Scophthalmus maximus L.), a carnivorous fish species with high dietary protein requirement, was chosen to examine the expression pattern of peptide and amino acid transporter genes along its digestive tract which was divided into six segments including stomach, pyloric caeca, rectum, and three equal parts of the remainder of the intestine. The results showed that the expression of two peptide and eleven amino acid transporters genes exhibited distinct patterns. Peptide transporter 1 (PepT1) was rich in proximal intestine while peptide transporter 2 (PepT2) was abundant in distal intestine. A number of neutral and cationic amino acid transporters expressed richly in whole intestine including B0-type amino acid transporter 1 (B0AT1), L-type amino acid transporter 2 (LAT2), T-type amino acid transporter 1 (TAT1), proton-coupled amino acid transporter 1 (PAT1), y+L-type amino acid transporter 1 (y+LAT1), and cationic amino acid transporter 2 (CAT2) while ASC amino acid transporter 2 (ASCT2), sodium-coupled neutral amino acid transporter 2 (SNAT2), and y+L-type amino acid transporter 2 (y+LAT2) abundantly expressed in stomach. In addition, system b0,+ transporters (rBAT and b0,+AT) existed richly in distal intestine. These findings comprehensively characterized the distribution of solute carrier family proteins, which revealed the relative importance of peptide and amino acid absorption through luminal membrane. Our findings are helpful to understand the mechanism of the utilization of dietary protein in fish with a short digestive tract.

  14. Surface Drifters Track the Fate of Greenland Ice Sheet Meltwater

    NASA Astrophysics Data System (ADS)

    Hauri, Claudine; Truffer, Martin; Winsor, Peter; Lennert, Kunuk

    2014-07-01

    Understanding the fate and influence of glacial meltwater in heavily ice-covered fjord systems has proven difficult because previous measurement platforms were con­strained to deeper water to keep instrumentation safe from drifting icebergs. Now, using novel, satellite-tracked devices that can with­ stand multiple collisions with ice blocks (see Figure 1) without incurring much damage, scientists have obtained new and detailed data about the role of Greenland Ice Sheet meltwater and its trajectories through God­thåbsfjord in western Greenland.

  15. Operation of a Radar Altimeter over the Greenland Ice Sheet

    NASA Technical Reports Server (NTRS)

    Grund, Matthew D.

    1996-01-01

    This thesis presents documentation for the Advanced Application Flight Experiment (AAFE) pulse compression radar altimeter and its role in the NASA Multisensor Airborne Altimetry Experiment over Greenland in 1993. The AAFE Altimeter is a Ku-band microwave radar which has demonstrated 14 centimeter range precision in operation over arctic ice. Recent repairs and improvements were required to make the Greenland missions possible. Transmitter, receiver and software modifications, as well as the integration of a GPS receiver are thoroughly documented. Procedures for installation, and operation of the radar are described. Finally, suggestions are made for further system improvements.

  16. North and northeast Greenland ice discharge from satellite radar interferometry

    SciTech Connect

    Rignot, E.J.; Gogineni, S.P.; Krabill, W.B.

    1997-05-09

    Ice discharge from north and northeast Greenland calculated from satellite radar interferometry data of 14 outlet glaciers is 3.5 times that estimated from iceberg production. The satellite estimates, obtained at the grounding line of the outlet glaciers, differ from those obtained at the glacier front, because basal melting is extensive at the underside of the floating glacier sections. The results suggest that the north and northeast parts of the Greenland ice sheet may be thinning and contributing positively to sea-level rise. 24 refs., 3 figs., 1 tab.

  17. Minority Women's Health: American Indians/Alaska Natives

    MedlinePlus

    ... Health > American Indians/Alaska Natives Minority Women's Health American Indians/Alaska Natives Related information How to Talk to ... disease. Return to top Health conditions common in American Indian and Alaska Native women Accidents Alcoholism and drug ...

  18. Late glacial and Holocene history of the Greenland Ice Sheet margin, Nunatarssuaq, Northwestern Greenland

    NASA Astrophysics Data System (ADS)

    Farnsworth, L. B.; Kelly, M. A.; Axford, Y.; Bromley, G. R.; Osterberg, E. C.; Howley, J. A.; Zimmerman, S. R. H.; Jackson, M. S.; Lasher, G. E.; McFarlin, J. M.

    2015-12-01

    Defining the late glacial and Holocene fluctuations of the Greenland Ice Sheet (GrIS) margin, particularly during periods that were as warm or warmer than present, provides a longer-term perspective on present ice margin fluctuations and informs how the GrIS may respond to future climate conditions. We focus on mapping and dating past GrIS extents in the Nunatarssuaq region of northwestern Greenland. During the summer of 2014, we conducted geomorphic mapping and collected rock samples for 10Be surface exposure dating as well as subfossil plant samples for 14C dating. We also obtained sediment cores from an ice-proximal lake. Preliminary 10Be ages of boulders deposited during deglaciation of the GrIS subsequent to the Last Glacial Maximum range from ~30-15 ka. The apparently older ages of some samples indicate the presence of 10Be inherited from prior periods of exposure. These ages suggest deglaciation occurred by ~15 ka however further data are needed to test this hypothesis. Subfossil plants exposed at the GrIS margin on shear planes date to ~ 4.6-4.8 cal. ka BP and indicate less extensive ice during middle Holocene time. Additional radiocarbon ages from in situ subfossil plants on a nunatak date to ~3.1 cal. ka BP. Geomorphic mapping of glacial landforms near Nordsø, a large proglacial lake, including grounding lines, moraines, paleo-shorelines, and deltas, indicate the existence of a higher lake level that resulted from a more extensive GrIS margin likely during Holocene time. A fresh drift limit, characterized by unweathered, lichen-free clasts approximately 30-50 m distal to the modern GrIS margin, is estimated to be late Holocene in age. 10Be dating of samples from these geomorphic features is in progress. Radiocarbon ages of subfossil plants exposed by recent retreat of the GrIS margin suggest that the GrIS was at or behind its present location at AD ~1650-1800 and ~1816-1889. Results thus far indicate that the GrIS margin in northwestern Greenland

  19. Forestry timber typing. Tanana demonstration project, Alaska ASVT. [Alaska

    NASA Technical Reports Server (NTRS)

    Morrissey, L. A.; Ambrosia, V. G.

    1982-01-01

    The feasibility of using LANDSAT digital data in conjunction with topographic data to delineate commercial forests by stand size and crown closure in the Tanana River basin of Alaska was tested. A modified clustering approach using two LANDSAT dates to generate an initial forest type classification was then refined with topographic data. To further demonstrate the ability of remotely sensed data in a fire protection planning framework, the timber type data were subsequently integrated with terrain information to generate a fire hazard map of the study area. This map provides valuable assistance in initial attack planning, determining equipment accessibility, and fire growth modeling. The resulting data sets were incorporated into the Alaska Department of Natural Resources geographic information system for subsequent utilization.

  20. Lithospheric flexure across an extremely stretched and detached transform margin: Example from the East Greenland Ridge and Greenland FZ in the Norwegian-Greenland Sea.

    NASA Astrophysics Data System (ADS)

    Døssing, A.; Watts, A. B.

    2009-04-01

    The 250 km long East Greenland Ridge (EGR) is located along the Greenland Fracture Zone (GFZ), which is part of a first-order plate tectonic feature in the Norwegian-Greenland Sea that formed when Eocene seafloor spreading was translated along the De Geer megashear region between Greenland and Svalbard to the Arctic Ocean. The EGR rises abruptly about 250 km west from the Mohns-Knipovich Ridge axis in Chron 13 (33.3 Ma) crust and continues to Chron 24 (54.4 Ma) crust. Results of recently acquired wide-angle and MCS seismic data have shown that the EGR and an adjacent faulted basin province to the north of the ridge represent a continental sliver detached from the incipient NE Greenland and SW Barents Sea margins. Crustal thicknesses were found to be around 10 km (Døssing et al., 2008). The EGR-GFZ tectonic setting can therefore be rendered as an extremely stretched transform margin. A strong asymmetry is observed across the GFZ going from south to north with (i) a long wave-length downwards deflection of the oceanic crust, (ii) a steep southern flank of the EGR reaching more than 4 km above the predicted lithospheric thermal contraction level, and (iii) a gentle northern flank of the ridge dipping towards the faulted basin province. Hence, the ridge resembles the characteristics of other anomalously shallow, FZ parallel, transverse ridges. We propose a model in which flexural response of the lithosphere to normal faulting is responsible for the formation of the ridge. Interpretations of three, ~250 km long, seismic profiles normal to the GFZ are used to model the across-strike basement geometry. The results indicate that the observed lithospheric flexure was formed due to ~20 km extension normal to the GFZ along low-angle faults. Ref: Døssing, A., T. Dahl-Jensen, H. Thybo, R. Mjelde, and Y. Nishimura (2008), East Greenland Ridge in the North Atlantic Ocean: An integrated geophysical study of a continental sliver in a boundary transform fault setting, J. Geophys

  1. 76 FR 303 - Alaska: Adequacy of Alaska's Municipal Solid Waste Landfill Permit Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ... From the Federal Register Online via the Government Publishing Office ] ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 239 and 258 Alaska: Adequacy of Alaska's Municipal Solid Waste Landfill Permit... proposes to approve Alaska's modification of its approved Municipal Solid Waste Landfill (MSWLF)...

  2. Fisheries Education in Alaska. Conference Report. Alaska Sea Grant Report 82-4.

    ERIC Educational Resources Information Center

    Smoker, William W., Ed.

    This conference was an attempt to have the fishing industry join the state of Alaska in building fisheries education programs. Topics addressed in papers presented at the conference include: (1) fisheries as a part of life in Alaska, addressing participation of Alaska natives in commercial fisheries and national efforts; (2) the international…

  3. Alaska Native Participation in the Civilian Conservation Corps. Alaska Historical Commission Studies in History No. 206.

    ERIC Educational Resources Information Center

    Sorensen, Connor; And Others

    The report is a finding aid to the sources which document the 1937 federal policy decision mandating that 50% of the enrollees in the Civilian Conservation Corps (CCC) in Alaska must be Alaska Natives and provides a list of the Native CCC projects in Alaska. The finding aid section is organized according to the location of the collections and…

  4. Greenland Ice Sheet Surface Elevation at Summit, Greenland: 2007-2013

    NASA Astrophysics Data System (ADS)

    Lutz, E.; Hawley, R. L.; Herring, T.

    2013-12-01

    Quantifying surface elevation change is essential for ice sheet mass balance estimates. We assessed surface elevation and elevation change of the Greenland Ice Sheet at a range of spatial scales using six years of monthly GPS surveys conducted near Summit between 8/2007 and 3/2013. The ~11 km route consists of 15 transects that run parallel and orthogonal to IceSat's groundtrack 412 and includes 121 repeat locations spatially distributed along the route (Figure 1). Horizontal velocities and velocity gradients derived from base station and transect positions agree closely with previous studies. At the survey scale, no significant linear elevation trend is evident over the study period. However, local- and transect-scale time series revealed significant elevation increases of 1--2 cm per year in the central and southern regions of the survey that spatially and temporally may correlate with wind transport events from Summit station. This finding illustrates how sample scale (e.g., density, location and extent) affects surface elevation estimates critical to remote sensing validation and mass balance estimation. Spectral time series analysis showed that the expected annual elevation cycle was dwarfed by a two-year periodicity that dominated nearly all time series. The elevation maximum of Winter 2012-2013 fell short of the expected elevation peak, possibly due to accelerated compaction forced by high temperatures in the preceding Summer of 2012. We also highlight spatial comparisons with elevation products from three NASA altimeters, including the Airborne Topographic Mapper (ATM), the Land, Vegetation, and Ice Sensor (LVIS), and the Multiple Altimeter Beam Experiment Lidar (MABEL). This unique long-term GPS dataset is valuable for assessing ice sheet elevation change at a range of spatial-temporal scales, and for validating remote sensing products. With continued effort this survey will provide invaluable ground-based observations linking ICESat, IceBridge and ICESat

  5. Unified Ecoregions of Alaska: 2001

    USGS Publications Warehouse

    Nowacki, Gregory J.; Spencer, Page; Fleming, Michael; Brock, Terry; Jorgenson, Torre

    2003-01-01

    Major ecosystems have been mapped and described for the State of Alaska and nearby areas. Ecoregion units are based on newly available datasets and field experience of ecologists, biologists, geologists and regional experts. Recently derived datasets for Alaska included climate parameters, vegetation, surficial geology and topography. Additional datasets incorporated in the mapping process were lithology, soils, permafrost, hydrography, fire regime and glaciation. Thirty two units are mapped using a combination of the approaches of Bailey (hierarchial), and Omernick (integrated). The ecoregions are grouped into two higher levels using a 'tri-archy' based on climate parameters, vegetation response and disturbance processes. The ecoregions are described with text, photos and tables on the published map.

  6. Alaska Natural Gas Transportation System

    SciTech Connect

    Jones, V.T.

    1984-04-27

    The proven reserves of natural gas in Prudhoe Bay remain the single largest block of reserves under US control. The sponsors of the Alaska Natural Gas Transportation System, including The Williams Companies, remain convinced that Alaskan gas will be increasingly important to meet future needs here in the lower 48 states. Both Canada and the US will increasingly have to turn to more costly supplies of gas as the closer, traditional areas of gas supply are exhausted. A principal motivation for Canada's participation in the ANGTS was the prospect of a jointly sponsored pipeline through Canada which would facilitate bringing frontier gas to market - through the so-called Dempster lateral. The high cost of transportation systems in the Artic necessitates pipelines with large capacities in order to minimize the cost of transportation per unit of gas delivered. It is clear that Canada still strongly supports the ANGTS project as a means of opening up the frontier resources of both Alaska and Canada.

  7. 1964 Great Alaska Earthquake: a photographic tour of Anchorage, Alaska

    USGS Publications Warehouse

    Thoms, Evan E.; Haeussler, Peter J.; Anderson, Rebecca D.; McGimsey, Robert G.

    2014-01-01

    On March 27, 1964, at 5:36 p.m., a magnitude 9.2 earthquake, the largest recorded earthquake in U.S. history, struck southcentral Alaska (fig. 1). The Great Alaska Earthquake (also known as the Good Friday Earthquake) occurred at a pivotal time in the history of earth science, and helped lead to the acceptance of plate tectonic theory (Cox, 1973; Brocher and others, 2014). All large subduction zone earthquakes are understood through insights learned from the 1964 event, and observations and interpretations of the earthquake have influenced the design of infrastructure and seismic monitoring systems now in place. The earthquake caused extensive damage across the State, and triggered local tsunamis that devastated the Alaskan towns of Whittier, Valdez, and Seward. In Anchorage, the main cause of damage was ground shaking, which lasted approximately 4.5 minutes. Many buildings could not withstand this motion and were damaged or collapsed even though their foundations remained intact. More significantly, ground shaking triggered a number of landslides along coastal and drainage valley bluffs underlain by the Bootlegger Cove Formation, a composite of facies containing variably mixed gravel, sand, silt, and clay which were deposited over much of upper Cook Inlet during the Late Pleistocene (Ulery and others, 1983). Cyclic (or strain) softening of the more sensitive clay facies caused overlying blocks of soil to slide sideways along surfaces dipping by only a few degrees. This guide is the document version of an interactive web map that was created as part of the commemoration events for the 50th anniversary of the 1964 Great Alaska Earthquake. It is accessible at the U.S. Geological Survey (USGS) Alaska Science Center website: http://alaska.usgs.gov/announcements/news/1964Earthquake/. The website features a map display with suggested tour stops in Anchorage, historical photographs taken shortly after the earthquake, repeat photography of selected sites, scanned documents

  8. Lidar observations of the Pinatubo aerosol layer at Thule, Greenland

    SciTech Connect

    Di Girolamo, P.; Cacciani, M.; Sarra, A. di; Fiocco, G.; Fua, D. )

    1994-06-22

    This paper summarizes lidar measurements from Thule Greenland made during EASOE. The lidar was able to track aerosols, primarily of volcanic origin, through the winter. Above 18 km the aerosol content was strongly dependent upon the location of the vortex, and did not show a substantial increase until the vortex broke up.

  9. Greenland ice sheet motion insensitive to exceptional meltwater forcing

    PubMed Central

    Tedstone, Andrew J.; Nienow, Peter W.; Sole, Andrew J.; Mair, Douglas W. F.; Cowton, Thomas R.; Bartholomew, Ian D.; King, Matt A.

    2013-01-01

    Changes to the dynamics of the Greenland ice sheet can be forced by various mechanisms including surface-melt–induced ice acceleration and oceanic forcing of marine-terminating glaciers. We use observations of ice motion to examine the surface melt–induced dynamic response of a land-terminating outlet glacier in southwest Greenland to the exceptional melting observed in 2012. During summer, meltwater generated on the Greenland ice sheet surface accesses the ice sheet bed, lubricating basal motion and resulting in periods of faster ice flow. However, the net impact of varying meltwater volumes upon seasonal and annual ice flow, and thus sea level rise, remains unclear. We show that two extreme melt events (98.6% of the Greenland ice sheet surface experienced melting on July 12, the most significant melt event since 1889, and 79.2% on July 29) and summer ice sheet runoff ∼3.9σ above the 1958–2011 mean resulted in enhanced summer ice motion relative to the average melt year of 2009. However, despite record summer melting, subsequent reduced winter ice motion resulted in 6% less net annual ice motion in 2012 than in 2009. Our findings suggest that surface melt–induced acceleration of land-terminating regions of the ice sheet will remain insignificant even under extreme melting scenarios. PMID:24248343

  10. The extreme melt across the Greenland ice sheet in 2012

    NASA Astrophysics Data System (ADS)

    Nghiem, S. V.; Hall, D. K.; Mote, T. L.; Tedesco, M.; Albert, M. R.; Keegan, K.; Shuman, C. A.; DiGirolamo, N. E.; Neumann, G.

    2012-10-01

    The discovery of the 2012 extreme melt event across almost the entire surface of the Greenland ice sheet is presented. Data from three different satellite sensors - including the Oceansat-2 scatterometer, the Moderate-resolution Imaging Spectroradiometer, and the Special Sensor Microwave Imager/Sounder - are combined to obtain composite melt maps, representing the most complete melt conditions detectable across the ice sheet. Satellite observations reveal that melt occurred at or near the surface of the Greenland ice sheet across 98.6% of its entire extent on 12 July 2012, including the usually cold polar areas at high altitudes like Summit in the dry snow facies of the ice sheet. This melt event coincided with an anomalous ridge of warm air that became stagnant over Greenland. As seen in melt occurrences from multiple ice core records at Summit reported in the published literature, such a melt event is rare with the last significant one occurring in 1889 and the next previous one around seven centuries earlier in the Medieval Warm Period. Given its rarity, the 2012 extreme melt across Greenland provides an exceptional opportunity for new studies in broad interdisciplinary geophysical research.

  11. Surface-atmosphere decoupling limits accumulation at Summit, Greenland.

    PubMed

    Berkelhammer, Max; Noone, David C; Steen-Larsen, Hans Christian; Bailey, Adriana; Cox, Christopher J; O'Neill, Michael S; Schneider, David; Steffen, Konrad; White, James W C

    2016-04-01

    Despite rapid melting in the coastal regions of the Greenland Ice Sheet, a significant area (~40%) of the ice sheet rarely experiences surface melting. In these regions, the controls on annual accumulation are poorly constrained owing to surface conditions (for example, surface clouds, blowing snow, and surface inversions), which render moisture flux estimates from myriad approaches (that is, eddy covariance, remote sensing, and direct observations) highly uncertain. Accumulation is partially determined by the temperature dependence of saturation vapor pressure, which influences the maximum humidity of air parcels reaching the ice sheet interior. However, independent proxies for surface temperature and accumulation from ice cores show that the response of accumulation to temperature is variable and not generally consistent with a purely thermodynamic control. Using three years of stable water vapor isotope profiles from a high altitude site on the Greenland Ice Sheet, we show that as the boundary layer becomes increasingly stable, a decoupling between the ice sheet and atmosphere occurs. The limited interaction between the ice sheet surface and free tropospheric air reduces the capacity for surface condensation to achieve the rate set by the humidity of the air parcels reaching interior Greenland. The isolation of the surface also acts to recycle sublimated moisture by recondensing it onto fog particles, which returns the moisture back to the surface through gravitational settling. The observations highlight a unique mechanism by which ice sheet mass is conserved, which has implications for understanding both past and future changes in accumulation rate and the isotopic signal in ice cores from Greenland.

  12. Project CAP. Boston Mountains Educational Cooperative, Greenland, Arkansas.

    ERIC Educational Resources Information Center

    Hamilton, Jack A.; Leffler, Jeanne

    This description of career education activities in Greenland, Arkansas, was prepared as part of a study conducted to identify evaluated, exemplary career education activities which represent the best of the current career education programs and practices referred to in Public Law 93-380. (See CE 018 212 for the final report of this study.) This…

  13. Supporting an Externally Developed Model of Education in Greenland

    ERIC Educational Resources Information Center

    Wyatt, Tasha R.

    2010-01-01

    This study investigated the adaptation process of an externally developed model of reform in Greenland's educational system. Under investigation was how reform leaders responded to the needs of the community after implementing an educational model developed in the United States by researchers at the Center for Research on Education, Diversity, and…

  14. 34 First Callisto solar burst spectrometer station in Greenland

    NASA Astrophysics Data System (ADS)

    Monstein, Christian

    2016-04-01

    In mid of March 2016 a new long wavelength station in Greenland was set into operation. It is a dual circular polarization, frequency agile solar radio burst spectrometer based on two Callisto spectrometers and the Long Wavelength Array antenna. During the commissioning phase several nice radio burst observations proved that the system works as expected.

  15. Cultural adaptation, compounding vulnerabilities and conjunctures in Norse Greenland

    PubMed Central

    Dugmore, Andrew J.; McGovern, Thomas H.; Vésteinsson, Orri; Arneborg, Jette; Streeter, Richard; Keller, Christian

    2012-01-01

    Norse Greenland has been seen as a classic case of maladaptation by an inflexible temperate zone society extending into the arctic and collapse driven by climate change. This paper, however, recognizes the successful arctic adaptation achieved in Norse Greenland and argues that, although climate change had impacts, the end of Norse settlement can only be truly understood as a complex socioenvironmental system that includes local and interregional interactions operating at different geographic and temporal scales and recognizes the cultural limits to adaptation of traditional ecological knowledge. This paper is not focused on a single discovery and its implications, an approach that can encourage monocausal and environmentally deterministic emphasis to explanation, but it is the product of sustained international interdisciplinary investigations in Greenland and the rest of the North Atlantic. It is based on data acquisitions, reinterpretation of established knowledge, and a somewhat different philosophical approach to the question of collapse. We argue that the Norse Greenlanders created a flexible and successful subsistence system that responded effectively to major environmental challenges but probably fell victim to a combination of conjunctures of large-scale historic processes and vulnerabilities created by their successful prior response to climate change. Their failure was an inability to anticipate an unknowable future, an inability to broaden their traditional ecological knowledge base, and a case of being too specialized, too small, and too isolated to be able to capitalize on and compete in the new protoworld system extending into the North Atlantic in the early 15th century. PMID:22371594

  16. Assessment of Glacial Isostatic Adjustment in Greenland using GPS

    NASA Astrophysics Data System (ADS)

    Khan, S. A.; Bevis, M. G.; Sasgen, I.; van Dam, T. M.; Wahr, J. M.; Wouters, B.; Bamber, J. L.; Willis, M. J.; Knudsen, P.; Helm, V.; Kuipers Munneke, P.; Muresan, I. S.

    2015-12-01

    The Greenland GPS network (GNET) was constructed to provide a new means to assess viscoelastic and elastic adjustments driven by past and present-day changes in ice mass. Here we assess existing glacial isostatic adjustments (GIA) predictions by analysing 1995-2015 data from 61 continuous GPS receivers located along the margin of the Greenland ice sheet. Since GPS receivers measure both the GIA and elastic signals, we isolate GIA, by removing the elastic adjustments of the lithosphere due to present-day mass changes using high-resolution fields of ice surface elevation change derived from satellite and airborne altimetry measurements (ERS1/2, ICESat, ATM, ENVISAT, and CryoSat-2). For most GPS stations, our observed GIA rates contradict GIA predictions; particularly, we find huge uplift rates in southeast Greenland of up to 14 mm/yr while models predict rates of 0-2 mm/yr. Our results suggest possible improvements of GIA predictions, and hence of the poorly constrained ice load history and Earth structure models for Greenland.

  17. Antarctic climate signature in the Greenland ice core record

    PubMed Central

    Barker, Stephen; Knorr, Gregor

    2007-01-01

    A numerical algorithm is applied to the Greenland Ice Sheet Project 2 (GISP2) dust record from Greenland to remove the abrupt changes in dust flux associated with the Dansgaard–Oeschger (D–O) oscillations of the last glacial period. The procedure is based on the assumption that the rapid changes in dust are associated with large-scale changes in atmospheric transport and implies that D–O oscillations (in terms of their atmospheric imprint) are more symmetric in form than can be inferred from Greenland temperature records. After removal of the abrupt shifts the residual, dejumped dust record is found to match Antarctic climate variability with a temporal lag of several hundred years. It is argued that such variability may reflect changes in the source region of Greenland dust (thought to be the deserts of eastern Asia). Other records from this region and more globally also reveal Antarctic-style variability and suggest that this signal is globally pervasive. This provides the potential basis for suggesting a more important role for gradual changes in triggering more abrupt transitions in the climate system. PMID:17954910

  18. A high-resolution record of Greenland mass balance

    NASA Astrophysics Data System (ADS)

    McMillan, Malcolm; Leeson, Amber; Shepherd, Andrew; Briggs, Kate; Armitage, Thomas W. K.; Hogg, Anna; Kuipers Munneke, Peter; Broeke, Michiel; Noël, Brice; Berg, Willem Jan; Ligtenberg, Stefan; Horwath, Martin; Groh, Andreas; Muir, Alan; Gilbert, Lin

    2016-07-01

    We map recent Greenland Ice Sheet elevation change at high spatial (5 km) and temporal (monthly) resolution using CryoSat-2 altimetry. After correcting for the impact of changing snowpack properties associated with unprecedented surface melting in 2012, we find good agreement (3 cm/yr bias) with airborne measurements. With the aid of regional climate and firn modeling, we compute high spatial and temporal resolution records of Greenland mass evolution, which correlate (R = 0.96) with monthly satellite gravimetry and reveal glacier dynamic imbalance. During 2011-2014, Greenland mass loss averaged 269 ± 51 Gt/yr. Atmospherically driven losses were widespread, with surface melt variability driving large fluctuations in the annual mass deficit. Terminus regions of five dynamically thinning glaciers, which constitute less than 1% of Greenland's area, contributed more than 12% of the net ice loss. This high-resolution record demonstrates that mass deficits extending over small spatial and temporal scales have made a relatively large contribution to recent ice sheet imbalance.

  19. Greenland ice sheet motion insensitive to exceptional meltwater forcing.

    PubMed

    Tedstone, Andrew J; Nienow, Peter W; Sole, Andrew J; Mair, Douglas W F; Cowton, Thomas R; Bartholomew, Ian D; King, Matt A

    2013-12-01

    Changes to the dynamics of the Greenland ice sheet can be forced by various mechanisms including surface-melt-induced ice acceleration and oceanic forcing of marine-terminating glaciers. We use observations of ice motion to examine the surface melt-induced dynamic response of a land-terminating outlet glacier in southwest Greenland to the exceptional melting observed in 2012. During summer, meltwater generated on the Greenland ice sheet surface accesses the ice sheet bed, lubricating basal motion and resulting in periods of faster ice flow. However, the net impact of varying meltwater volumes upon seasonal and annual ice flow, and thus sea level rise, remains unclear. We show that two extreme melt events (98.6% of the Greenland ice sheet surface experienced melting on July 12, the most significant melt event since 1889, and 79.2% on July 29) and summer ice sheet runoff ~3.9 σ above the 1958-2011 mean resulted in enhanced summer ice motion relative to the average melt year of 2009. However, despite record summer melting, subsequent reduced winter ice motion resulted in 6% less net annual ice motion in 2012 than in 2009. Our findings suggest that surface melt-induced acceleration of land-terminating regions of the ice sheet will remain insignificant even under extreme melting scenarios.

  20. Holocene coastal glaciation of Alaska

    NASA Astrophysics Data System (ADS)

    Calkin, Parker E.; Wiles, Gregory C.; Barclay, David J.

    2001-01-01

    Holocene fluctuations of the three cirque glaciers on the Seward Peninsula and five groups of tidewater- and land-terminating glaciers along the northernmost Gulf of Alaska, provide a proxy record of late Holocene climatic change. Furthermore, the movements of the coastal glaciers were relevant to late Holocene native American migration. The earliest expansion was recorded about 6850 yr BP by Hubbard Glacier at the head of Yakutat Bay in the Gulf of Alaska; however, its down-fjord advance to the bay mouth was delayed until ˜2700 BP. Similarly, expansions of the Icy Bay, Bering, and McCarty glaciers occurred near their present termini by ˜3600-3000 BP, compatible with marked cooling and precipitation increases suggested by the Alaskan pollen record. Decrease in glacier activity ˜2000 BP was succeeded by advances of Gulf coastal glaciers between 1500 and 1300 BP, correlative with early Medieval expansions across the Northern Hemisphere. A Medieval Optimum, encompassing at least a few centuries prior to AD 1200 is recognized by general retreat of land-terminating glaciers, but not of all tidewater glaciers. Little Ice Age advances of land-based glaciers, many dated with the precision of tree-ring cross-dating, were centered on the middle 13th or early 15th centuries, the middle 17th and the last half of the 19th century A.D. Strong synchrony of these events across coastal Alaska is evident.

  1. Greenlandic Microbiomes and Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Jacobsen, C. S.; Nielsen, M. S.; Priemé, A.; Holben, W. E.; Stibal, M.; Morales, S.; Bælum, J.; Elberling, B.; Kuhry, P.; Hugelius, G.

    2014-12-01

    Thawing permafrost and the resulting mineralization of previously frozen organic carbon (C) and nitrogen (N) are considered important future feedbacks from terrestrial ecosystems to the atmosphere. We characterized two contrasting permafrost cores as well as 21 top permafrost cores from Zackenberg in High-Arctic Greenland which is a site characterized by progressive permafrost thawing of more than 1 cm y-1 since 1996. Samples have been analyzed for total C and N content, dissolved C and N as well as the potential production of carbon dioxide, methane and nitrous oxide in an incubation experiment. 10 days after the thawing was initiated, rRNA from selected samples were extracted, transformed into cDNA and cloned to obtain an overview of the most abundant active bacterial populations in the incubation experiment. A total of 697 clones were successfully sequenced, yielding 21 unique OTUs. Despite the relatively high coverage values the diversity of bacteria in the samples was low (with a maximum Shannon-Wiener diversity index of 2.1). Firmicutes (6 OTUs, 45-77% of clones) and Gammaproteobacteria (5 OTUs, 19-47% of clones) were the dominant groups in the samples, with Betaproteobacteria (4 OTUs), Actinobacteria (4 OTUs), Alphaproteobacteria (1 OTU) and Bacteroidetes (1 OTU) being less dominant. These characterizations revealed that those bacteria that are able to quickly colonize the thawing permafrost are mainly related to three groups of bacterial clones: Lysinibacillus; Pseudomonas and Clostridium. Quantification of functional genes related to soil nitrogen transformation were performed both on the DNA and on the mRNA level using primers specific for genes involved in production of nitrous oxide (nirS, nirK) and consumption of nitrous oxide (nosZ). This showed that the genes were found in most soils, but that they only were expressed at a low level. We further measured the rates of nitrous oxide release from the soils and found that these were not clearly related to

  2. Modeled variations of precipitation over the Greenland Ice Sheet

    SciTech Connect

    Bromwich, D.H.; Robasky, F.M.; Bolzan, J.F. ); Keen, R.A.

    1993-07-01

    A parameterization of the synoptic activity at 500 hPa and a simple orographic scheme are used to model the spatial and temporal variations of precipitation over the Greenland Ice Sheet for 1963-88 from information from the National Meteorological Center (NMC). Most major spatial characteristics of the observed accumulation distribution are reproduced. The modeled time-averaged total precipitation amount over Greenland is within the range of values determined by other investigators from surface-based observations. A downward trend in simulated ice sheet precipitation over the 26 years is found, supported by a number of lines of evidence. This negative precipitation trend would mean that the Greenland Ice Sheet, depending on its 1963 mass balance state, has over the 1963-88 period either decreased its negative, or increased its positive, contribution to recently observed global sea level rise. Superimposed on the declining simulated precipitation rate for the entire ice sheet is a pronounced 3-5-yr periodicity. This is prominent in the observed and modeled precipitation time series from Summit, Greenland. This cycle shows some aspects in common with the Southern Oscillation. Some deficiencies in the NMC analyses were highlighted by this work. A large jump in simulated precipitation amounts at Summit around 1962, which is not verified by accumulation data, is inferred to be due to an artificial increase in cyclonic activity at 500 hPa associated with the NMC change from manual to numerical analyses. The activity of the storm track along the west coast of Greenland appears to be anomalously low in the NMC analyses, perhaps due to mesoscale cyclogenesis that is not resolved by the NMC analysis scheme. 71 refs., 21 figs., 1 tab.

  3. Radiostratigraphy and age structure of the Greenland Ice Sheet

    PubMed Central

    MacGregor, Joseph A; Fahnestock, Mark A; Catania, Ginny A; Paden, John D; Prasad Gogineni, S; Young, S Keith; Rybarski, Susan C; Mabrey, Alexandria N; Wagman, Benjamin M; Morlighem, Mathieu

    2015-01-01

    Several decades of ice-penetrating radar surveys of the Greenland and Antarctic ice sheets have observed numerous widespread internal reflections. Analysis of this radiostratigraphy has produced valuable insights into ice sheet dynamics and motivates additional mapping of these reflections. Here we present a comprehensive deep radiostratigraphy of the Greenland Ice Sheet from airborne deep ice-penetrating radar data collected over Greenland by The University of Kansas between 1993 and 2013. To map this radiostratigraphy efficiently, we developed new techniques for predicting reflection slope from the phase recorded by coherent radars. When integrated along track, these slope fields predict the radiostratigraphy and simplify semiautomatic reflection tracing. Core-intersecting reflections were dated using synchronized depth-age relationships for six deep ice cores. Additional reflections were dated by matching reflections between transects and by extending reflection-inferred depth-age relationships using the local effective vertical strain rate. The oldest reflections, dating to the Eemian period, are found mostly in the northern part of the ice sheet. Within the onset regions of several fast-flowing outlet glaciers and ice streams, reflections typically do not conform to the bed topography. Disrupted radiostratigraphy is also observed in a region north of the Northeast Greenland Ice Stream that is not presently flowing rapidly. Dated reflections are used to generate a gridded age volume for most of the ice sheet and also to determine the depths of key climate transitions that were not observed directly. This radiostratigraphy provides a new constraint on the dynamics and history of the Greenland Ice Sheet. Key Points Phase information predicts reflection slope and simplifies reflection tracing Reflections can be dated away from ice cores using a simple ice flow model Radiostratigraphy is often disrupted near the onset of fast ice flow PMID:26213664

  4. Moho, LAB and crustal velocities underneath central-eastern Greenland

    NASA Astrophysics Data System (ADS)

    Kraft, H. A.; Thybo, H.

    2014-12-01

    Major parts of Greenland are covered with up to 3.4 km of ice. Due to logistical challenges connected to the ice only very sparse geophysical information is available. We present here results of the TopoGreenland project, which forms the first regional seismic experiment conducted on the Greenlandic ice shield. Our objective is to gain detailed information about the lithospheric structure and to connect it with topographic features, the recent substantial uplift and the earlier history of rifting and break-up in the region. We focus on a 200 km x 600 km large area in central-eastern Greenland, where 22 broadband seismometers were installed between June 2009 and May 2012. 10 of those were operating on the ice cap, 12 on bedrock. 16 of the stations were installed along a 600 km long profile at 70°N, from Scorsbysund to the centre of the ice cap. The remaining 6 stations covered a 200 km wide area north of this profile. In addition data from 6 permanent and long-term stations from the GLISN network were integrated. Here we present models from P- and S- receiver function (PRF, SRF) calculations and Rayleigh wave tomography. The RF calculations were used to map Moho and LAB depths and to have well constrained input parameters for the tomography. From the Rayleigh wave tomography we then obtain models for crustal shear-velocities. The PRF for the stations on the ice cap show multiples with very high amplitudes from within the ice, why we decided to derive Moho and LAB depths for those stations from SRF. The results will be compared with a seismic refraction profile acquired in the same region and then linked to topographic features like the uplift of the mountain chain in East Greenland.

  5. Linking petrology and seismology of the southwest Greenland lithosphere

    NASA Astrophysics Data System (ADS)

    Lesher, C. E.; Vestergaard, C.; Brown, E.; Schutt, D.

    2015-12-01

    Mantle xenoliths from late-Proterozoic diamond-bearing kimberlitic dikes in the Kangerlussuaq, Sarfartoq and Maniitsoq areas of southwestern Greenland provide constraints on the composition and thermal state of lithospheric mantle beneath Greenland to depths of ~200 km [1]. Similarly, surface wave tomography studies carried out as part of the GLATIS project use a range of Rayleigh wave periods sensitive to structures at a similar depth interval within southwestern Greenland lithospheric mantle [2]. Here we link petrologic and seismologic constraints on the mantle lithosphere beneath Greenland utilizing methods of [3] that show that inferred chemical and mineralogical stratification inferred from petrology, showing mantle peridotite transitioning from garnet-free harzburgite to garnet lherzolite between ~70 and 180 km, cannot readily be resolved with fundamental mode Rayleigh waves. On the other hand, comparing phase velocities predicted from xenolith compositions, mineralogy and last equilibration temperatures and pressures, defining the continental geotherm during late-Proterozoic time, with those for the present-day mantle lithosphere suggest significant cooling of the cratonic mantle to a modern geotherm characterized by a heat flux of 30 mW/m2 and average crustal heat production of 0.3 mW/m3 [4]. These preliminary findings point to the weak dependence of shear wave velocities on mantle peridotite composition and mineralogy, and further illustrate its strong temperature dependence. Comparison of ancient and modern continental geotherms made possible by combining petrologic and seismological data, as shown here for southwest Greenland, provide additional constraints on secular cooling of cratonic regions linked to large-scale tectonic processes. [1] Bizzarro et al., 2003, CMP, 146; Sand et al., Lithos, 112. [2] Darbyshire et al., 2004, GJI, 158. [3] Schutt and Lesher, 2006, JGR, 111. [4] Meirerbachtol et al., 2015, JGR/ES, 120.

  6. Seasonal changes in Fe along a glaciated Greenlandic fjord.

    NASA Astrophysics Data System (ADS)

    Hopwood, Mark; Connelly, Douglas; Arendt, Kristine; Juul-Pedersen, Thomas; Stinchcombe, Mark; Meire, Lorenz; Esposito, Mario; Krishna, Ram

    2016-03-01

    Greenland's ice sheet is the second largest on Earth, and is under threat from a warming Arctic climate. An increase in freshwater discharge from Greenland has the potential to strongly influence the composition of adjacent water masses with the largest impact on marine ecosystems likely to be found within the glaciated fjords. Here we demonstrate that physical and chemical estuarine processes within a large Greenlandic fjord are critical factors in determining the fate of meltwater derived nutrients and particles, especially for non-conservative elements such as Fe. Concentrations of Fe and macronutrients in surface waters along Godthåbsfjord, a southwest Greenlandic fjord with freshwater input from 6 glaciers, changed markedly between the onset and peak of the meltwater season due to the development of a thin (<10 m), outflowing, low-salinity surface layer. Dissolved (<0.2 µm) Fe concentrations in meltwater entering Godthåbsfjord (200 nM), in freshly melted glacial ice (mean 38 nM) and in surface waters close to a land terminating glacial system (80 nM) all indicated high Fe inputs into the fjord in summer. Total dissolvable (unfiltered at pH <2.0) Fe was similarly high with concentrations always in excess of 100 nM throughout the fjord and reaching up to 5.0 µM close to glacial outflows in summer. Yet, despite the large seasonal freshwater influx into the fjord, Fe concentrations near the fjord mouth in the out-flowing surface layer were similar in summer to those measured before the meltwater season. Furthermore, turbidity profiles indicated that sub-glacial particulate Fe inputs may not actually mix into the outflowing surface layer of this fjord. Emphasis has previously been placed on the possibility of increased Fe export from Greenland as meltwater fluxes increase. Here we suggest that in-fjord processes may be effective at removing Fe from surface waters before it can be exported to coastal seas.

  7. Ice stream retreat following the LGM and onset of the west Greenland current in Uummannaq Trough, west Greenland

    NASA Astrophysics Data System (ADS)

    Sheldon, Christina; Jennings, Anne; Andrews, John T.; Ó Cofaigh, Colm; Hogan, Kelly; Dowdeswell, Julian A.; Seidenkrantz, Marit-Solveig

    2016-09-01

    The deglacial history and oceanography of Uummannaq Trough, central West Greenland continental shelf, was investigated using foraminiferal, sedimentological, and bathymetric records together with a radiocarbon chronology, providing a timeline for the retreat of glacial ice after the Last Glacial Maximum (LGM). To map ice stream retreat, data were collected from cores from the outer (JR175-VC45 and JR175-VC43) and inner (JR175-VC42) Uummannaq Trough. A large ice stream, fed by confluent glaciers draining the interior of the Greenland Ice Sheet, extended across the outer shelf during the LGM and was in retreat by 15.0 cal kyr BP. Foraminiferal data indicate that the 'warm' West Greenland Current (WGC) was established prior to 14.0 cal kyr BP, which is the hitherto earliest record of Atlantic Water found on the West Greenland shelf. For each of the cores, foraminifera indicate that ice sheet retreat was followed quickly by incursion of the WGC, suggesting that the warm water may have enhanced ice retreat. Prior to the Younger Dryas cold event, the radiocarbon chronology indicates that the ice sheet retreated to the mid-shelf, where it subsequently stabilised and formed a large grounding-zone wedge (GZW). After the Younger Dryas, around 11.5 cal kyr BP, the ice retreated rapidly from the GZW and into the fjords.

  8. Mycobacterium tuberculosis outbreak strain of Danish origin spreading at worrying rates among greenland-born persons in Denmark and Greenland.

    PubMed

    Lillebaek, T; Andersen, A B; Rasmussen, E M; Kamper-Jørgensen, Z; Pedersen, M K; Bjorn-Mortensen, K; Ladefoged, K; Thomsen, V O

    2013-12-01

    Transmission of Mycobacterium tuberculosis continues at high rates among Greenland-born persons in Greenland and Denmark, with 203 and 450 notified cases per 10(5) population, respectively, in the year 2010. Here, we document that the predominant M. tuberculosis outbreak strain C2/1112-15 of Danish origin has been transmitted to Greenland-born persons in Denmark and subsequently to Greenland, where it is spreading at worrying rates and adding to the already heavy tuberculosis burden in this population group. It is now clear that the C2/1112-15 strain is able to gain new territories using a new population group as the "vehicle." Thus, it might have the ability to spread even further, considering the potential clinical consequences of strain diversity such as that seen in the widely spread Beijing genotype. The introduction of the predominant M. tuberculosis outbreak strain C2/1112-15 into the Arctic circumpolar region is a worrying tendency which deserves attention. We need to monitor whether this strain already has, or will, spread to other countries.

  9. Palatability of water-soluble extracts of protein sources and replacement of fishmeal by a selected mixture of protein sources for juvenile turbot ( Scophthalmus maximus)

    NASA Astrophysics Data System (ADS)

    Dong, Chun; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei

    2016-06-01

    Poor palatability is a limiting factor for replacing fishmeal with other protein sources in aquaculture. The water-soluble molecules with low molecular weights are the major determinants of the palatability of diets. The present study was conducted to investigate the palatability of water-soluble extracts from single protein source (single extract pellets) and the mixture of these extracts with different proportions (blended extract pellets) in juvenile turbot ( Scophthalmus maximus). Then according to the palatability of blended extract pellets, an optimal mixture proportion was selected, and a new protein source made from raw protein materials with the selected proportion was formulated to replace fishmeal. Summarily, the palatability of single extract pellets for turbot was descendent from fishmeal to pet-food grade poultry by-product meal, wheat gluten meal, soybean meal, peanut meal, meat and bone meal, and corn gluten meal. Subsequently, according to the palatability of single extract pellets, 52 kinds of blended extract pellets were designed to test their palatability. The results showed that the pellets presented remarkably different palatability, and the optimal one was diet 52 (wheat gluten meal: pet-food grade poultry by-product meal: meat and bone meal: corn gluten meal = 1:6:1:2). The highest ingestion ratio (the number of pellets ingested/the number of pellets fed) was 0.73 ± 0.03, which was observed in Diet 52. Then five isonitrogenous (52% crude protein) and isocaloric (20 kJ g-1 gross energy) diets were formulated by replacing 0 (control), 35%, 50%, 65% and 80% of fishmeal with No.52 blending proportion. After a 10-weeks feeding trial, a consistent feed intake was found among all replacement treatments. Replacement level of fishmeal up to 35% did not significantly influence final body weight, specific growth rate, feed efficiency ratio, and protein efficiency ratio of turbot. Therefore, the water-soluble extracts of protein sources play an

  10. How much can Greenland melt? An upper bound on mass loss from the Greenland Ice Sheet through surface melting

    NASA Astrophysics Data System (ADS)

    Liu, X.; Bassis, J. N.

    2015-12-01

    With observations showing accelerated mass loss from the Greenland Ice Sheet due to surface melt, the Greenland Ice Sheet is becoming one of the most significant contributors to sea level rise. The contribution of the Greenland Ice Sheet o sea level rise is likely to accelerate in the coming decade and centuries as atmospheric temperatures continue to rise, potentially triggering ever larger surface melt rates. However, at present considerable uncertainty remains in projecting the contribution to sea level of the Greenland Ice Sheet both due to uncertainty in atmospheric forcing and the ice sheet response to climate forcing. Here we seek an upper bound on the contribution of surface melt from the Greenland to sea level rise in the coming century using a surface energy balance model coupled to an englacial model. We use IPCC Representative Concentration Pathways (RCP8.5, RCP6, RCP4.5, RCP2.6) climate scenarios from an ensemble of global climate models in our simulations to project the maximum rate of ice volume loss and related sea-level rise associated with surface melting. To estimate the upper bound, we assume the Greenland Ice Sheet is perpetually covered in thick clouds, which maximize longwave radiation to the ice sheet. We further assume that deposition of black carbon darkens the ice substantially turning it nearly black, substantially reducing its albedo. Although assuming that all melt water not stored in the snow/firn is instantaneously transported off the ice sheet increases mass loss in the short term, refreezing of retained water warms the ice and may lead to more melt in the long term. Hence we examine both assumptions and use the scenario that leads to the most surface melt by 2100. Preliminary models results suggest that under the most aggressive climate forcing, surface melt from the Greenland Ice Sheet contributes ~1 m to sea level by the year 2100. This is a significant contribution and ignores dynamic effects. We also examined a lower bound

  11. Alaska Volcano Observatory at 20

    NASA Astrophysics Data System (ADS)

    Eichelberger, J. C.

    2008-12-01

    The Alaska Volcano Observatory (AVO) was established in 1988 in the wake of the 1986 Augustine eruption through a congressional earmark. Even within the volcanological community, there was skepticism about AVO. Populations directly at risk in Alaska were small compared to Cascadia, and the logistical costs of installing and maintaining monitoring equipment were much higher. Questions were raised concerning the technical feasibility of keeping seismic stations operating through the long, dark, stormy Alaska winters. Some argued that AVO should simply cover Augustine with instruments and wait for the next eruption there, expected in the mid 90s (but delayed until 2006), rather than stretching to instrument as many volcanoes as possible. No sooner was AVO in place than Redoubt erupted and a fully loaded passenger 747 strayed into the eruption cloud between Anchorage and Fairbanks, causing a powerless glide to within a minute of impact before the pilot could restart two engines and limp into Anchorage. This event forcefully made the case that volcano hazard mitigation is not just about people and infrastructure on the ground, and is particularly important in the heavily traveled North Pacific where options for flight diversion are few. In 1996, new funding became available through an FAA earmark to aggressively extend volcano monitoring far into the Aleutian Islands with both ground-based networks and round-the-clock satellite monitoring. Beyond the Aleutians, AVO developed a monitoring partnership with Russians volcanologists at the Institute of Volcanology and Seismology in Petropavlovsk-Kamchatsky. The need to work together internationally on subduction phenomena that span borders led to formation of the Japan-Kamchatka-Alaska Subduction Processes (JKASP) consortium. JKASP meets approximately biennially in Sapporo, Petropavlovsk, and Fairbanks. In turn, these meetings and support from NSF and the Russian Academy of Sciences led to new international education and

  12. Greenland ice cores tell tales on the extent of the Greenland Ice Sheet during the warm climate Eemian period 130.000 - 115.000 years BP.

    NASA Astrophysics Data System (ADS)

    Dahl-Jensen, D.

    2012-12-01

    A new Greenland ice core has been drilled. The first results from the NEEM ice core are presented and then combined with the results from the other deep ice cores from the Greenland Ice Sheet. All the ice cores drilled though the Greenland ice sheets have been analyzed and the results show that all the ice cores contain ice from the last interglacial, the Eemian, near the base. Is it thus clear that the Greenland Ice Sheet did exist 124.000 years ago in the previous warm climate period where it was more than 5 deg C warmer over Greenland. The difference between the Eemian and the Holocene stable oxygen isotope values have been combined with an ice sheet flow model constrained by the ice core results and internal radio echo sounding layers to estimate the volume of the Greenland Ice Sheet 124.000 years ago. The results show that South Greenland has not been ice free during the Eemian period and that the sea level contribution from the Greenland Ice Sheet has been 2.0 +-0.5 m.

  13. Skeletal development and abnormalities of the vertebral column and of the fins in hatchery-reared turbot Scophthalmus maximus.

    PubMed

    Tong, X H; Liu, Q H; Xu, S H; Ma, D Y; Xiao, Z Z; Xiao, Y S; Li, J

    2012-03-01

    To describe the skeletal development and abnormalities in turbot Scophthalmus maximus, samples were collected every day from hatching to 60 days after hatching (DAH). A whole-mount cartilage and bone-staining technique was used. Vertebral ontogeny started with the formation of anterior haemal arches at 5·1 mm standard length (L(S) ) c. 11 DAH, and was completed by the full attainment of parapophyses at 16·9 mm L(S) c. 31 DAH. Vertebral centra started to develop at 6·3 mm L(S) c. 16 DAH and ossification in all centra was visible at 11·0 mm L(S) c. 25 DAH. The caudal fin appeared at 5·1 mm L(S) c. 11 DAH and ossification was visible at 20·6 mm L(S) c. 37 DAH. The onset of dorsal and anal fin elements appeared at 5·8 mm L(S) c. 15 DAH and 6·3 mm L(S) c. 16 DAH, respectively. Ossifications of both dorsal fin and anal fin were visible at 20·6 mm L(S) c. 37 DAH. The pectorals were the only fins present before first feeding, their ossifications were completed at 23·5 mm L(S) c. 48 DAH. Pelvic fins began forming at 7·2 mm L(S) c. 19 DAH and calcification of the whole structure was visible at 19·8 mm L(S) c. 36 DAH. In the present study, 24 types of skeletal abnormalities were observed. About 51% of individuals presented skeletal abnormalities, and the highest occurrence was found in the haemal region of the vertebral column. As for each developmental stage, the most common abnormalities were in the dorsal fin during early metamorphic period (stage 2), vertebral fusion during climax metamorphosis (stage 3) and caudal fin abnormality during both late-metamorphic period (stage 4) and post-metamorphic period (stage 5). Such research will be useful for early detection of skeletal malformations during different growth periods of reared S. maximus.

  14. Bioavailability of free lysine and protein-bound lysine from casein and fishmeal in juvenile turbot (Psetta maxima).

    PubMed

    Kroeckel, Saskia; Dietz, Carsten; Schulz, Carsten; Susenbeth, Andreas

    2015-03-14

    In the present study, a linear regression analysis between lysine intake and lysine retention was conducted to investigate the efficiency of lysine utilisation (k(Lys)) at marginal lysine intake of either protein-bound or free lysine sources in juvenile turbot (Psetta maxima). For this purpose, nine isonitrogenous and isoenergetic diets were formulated to contain 2·25-4·12 g lysine/100 g crude protein (CP) to ensure that lysine was the first-limiting amino acid in all diets. The basal diet contained 2·25 g lysine/100 g CP. Graded levels of casein (Cas), fishmeal (FM) and L-lysine HCl (Lys) were added to the experimental diets to achieve stepwise lysine increments. A total of 240 fish (initial weight 50·1 g) were hand-fed all the experimental diets once daily until apparent satiation over a period of 56 d. Feed intake was significantly affected by dietary lysine concentration rather than by dietary lysine source. Specific growth rate increased significantly at higher lysine concentrations (P< 0·001). CP, crude lipid and crude ash contents in the whole body were affected by the dietary treatments. The linear regression slope between lysine retention and lysine intake (k(Lys)) was similar between all the dietary lysine sources. The k(Lys) values for the diets supplemented with Cas, Lys or FM were 0·833, 0·857 and 0·684, respectively. The bioavailability of lysine from the respective lysine sources was determined by a slope-ratio approach. The bioavailability of lysine (relative to the reference lysine source Cas) from FM and Lys was 82·1 and 103 %, respectively. Nutrient requirement for maintenance was in the range of 16·7-23·4 mg/kg(0·8) per d, and did not differ between the treatments. There were no significant differences in lysine utilisation efficiency or bioavailability of protein-bound or crystalline lysine from the respective sources observed when lysine was confirmed to be the first-limiting nutrient.

  15. Modelling spoilage of fresh turbot and evaluation of a time-temperature integrator (TTI) label under fluctuating temperature.

    PubMed

    Nuin, Maider; Alfaro, Begoña; Cruz, Ziortza; Argarate, Nerea; George, Susie; Le Marc, Yvan; Olley, June; Pin, Carmen

    2008-10-31

    Kinetic models were developed to predict the microbial spoilage and the sensory quality of fresh fish and to evaluate the efficiency of a commercial time-temperature integrator (TTI) label, Fresh Check(R), to monitor shelf life. Farmed turbot (Psetta maxima) samples were packaged in PVC film and stored at 0, 5, 10 and 15 degrees C. Microbial growth and sensory attributes were monitored at regular time intervals. The response of the Fresh Check device was measured at the same temperatures during the storage period. The sensory perception was quantified according to a global sensory indicator obtained by principal component analysis as well as to the Quality Index Method, QIM, as described by Rahman and Olley [Rahman, H.A., Olley, J., 1984. Assessment of sensory techniques for quality assessment of Australian fish. CSIRO Tasmanian Regional Laboratory. Occasional paper n. 8. Available from the Australian Maritime College library. Newnham. Tasmania]. Both methods were found equally valid to monitor the loss of sensory quality. The maximum specific growth rate of spoilage bacteria, the rate of change of the sensory indicators and the rate of change of the colour measurements of the TTI label were modelled as a function of temperature. The temperature had a similar effect on the bacteria, sensory and Fresh Check kinetics. At the time of sensory rejection, the bacterial load was ca. 10(5)-10(6) cfu/g. The end of shelf life indicated by the Fresh Check label was close to the sensory rejection time. The performance of the models was validated under fluctuating temperature conditions by comparing the predicted and measured values for all microbial, sensory and TTI responses. The models have been implemented in a Visual Basic add-in for Excel called "Fish Shelf Life Prediction (FSLP)". This program predicts sensory acceptability and growth of spoilage bacteria in fish and the response of the TTI at constant and fluctuating temperature conditions. The program is freely

  16. Miocene uplift of the NE Greenland margin linked to plate tectonics: Seismic evidence from the Greenland Fracture Zone, NE Atlantic

    NASA Astrophysics Data System (ADS)

    Døssing, Arne; Japsen, Peter; Watts, Anthony B.; Nielsen, Tove; Jokat, Wilfried; Thybo, Hans; Dahl-Jensen, Trine

    2016-02-01

    Tectonic models predict that following breakup, rift margins undergo only decaying thermal subsidence during their postrift evolution. However, postbreakup stratigraphy beneath the NE Atlantic shelves shows evidence of regional-scale unconformities, commonly cited as outer margin responses to inner margin episodic uplift, including the formation of coastal mountains. The origin of these events remains enigmatic. We present a seismic reflection study from the Greenland Fracture Zone-East Greenland Ridge (GFZ-EGR) and the NE Greenland shelf. We document a regional intra-Miocene seismic unconformity (IMU), which marks the termination of synrift deposition in the deep-sea basins and onset of (i) thermomechanical coupling across the GFZ, (ii) basin compression, and (iii) contourite deposition, north of the EGR. The onset of coupling across the GFZ is constrained by results of 2-D flexural backstripping. We explain the thermomechanical coupling and the deposition of contourites by the formation of a continuous plate boundary along the Mohns and Knipovich ridges, leading to an accelerated widening of the Fram Strait. We demonstrate that the IMU event is linked to onset of uplift and massive shelf progradation on the NE Greenland margin. Given an estimated middle to late Miocene (~15-10 Ma) age of the IMU, we speculate that the event is synchronous with uplift of the east and west Greenland margins. The correlation between margin uplift and plate motion changes further indicates that the uplift was triggered by plate tectonic forces, induced perhaps by a change in the Iceland plume (a hot pulse) and/or by changes in intraplate stresses related to global tectonics.

  17. Miocene uplift of the NE Greenland margin linked to plate tectonics: Seismic evidence from the Greenland Fracture Zone, NE Atlantic.

    NASA Astrophysics Data System (ADS)

    Døssing, Arne; Japsen, Peter; Watts, Anthony; Nielsen, Tove; Jokat, Wilfried; Thybo, Hans

    2016-04-01

    Tectonic models predict that, following breakup, rift margins undergo only decaying thermal subsidence during their post-rift evolution. However, post-breakup stratigraphy beneath the NE Atlantic shelves shows evidence of regional-scale unconformities, commonly cited as outer margin responses to inner margin episodic uplift, including the formation of coastal mountains. The origin of these events remains enigmatic. We present a seismic reflection study from the Greenland Fracture Zone - East Greenland Ridge (GFZ-EGR) and the NE Greenland shelf. We document a regional intra-Miocene seismic unconformity (IMU), which marks the termination of syn-rift deposition in the deep-sea basins and onset of: (i) thermo-mechanical coupling across the GFZ, (ii) basin compression, and (iii) contourite deposition, north of the EGR. The onset of coupling across the GFZ is constrained by results of 2-D flexural backstripping. We explain the thermo-mechanical coupling and the deposition of contourites by the formation of a continuous plate boundary along the Mohns and Knipovich ridges, leading to an accelerated widening of the Fram Strait. We demonstrate that the IMU event is linked to onset of uplift and massive shelf-progradation on the NE Greenland margin. Given an estimated middle-to-late Miocene (~15-10 Ma) age of the IMU, we speculate that the event is synchronous with uplift of the East and West Greenland margins. The correlation between margin uplift and plate-motion changes further indicates that the uplift was triggered by plate tectonic forces, induced perhaps by a change in the Iceland plume (a hot pulse) and/or by changes in intra-plate stresses related to global tectonics.

  18. Caledonian Deformation in Polydeformed Pre-Mississippian Rocks of the Northeast Brooks Range, Alaska

    NASA Astrophysics Data System (ADS)

    Johnson, B. G.; Toro, J.; Benowitz, J.

    2013-12-01

    In the northeastern Brooks Range of Alaska there are polydeformed metasedimentary and metavolcanic rocks exposed below a major pre-Mississippian unconformity. Elsewhere in northern Alaska it has been challenging to correlate the tectonic fabrics of these early Paleozoic to Neoproterozoic rocks to the different orogenic events of the Arctic because of the strong overprint of Mesozoic and Tertiary Brookian deformation. However, our recent field investigations along the Kongakut and Aichiklik rivers of ANWR have identified an older (pre-Brookian) structural event based on the orientation of penetrative cleavage planes and a contrast in folding style to Brookian structures. Many of the cleavage planes are north dipping and orientated parallel to the axial planes of south-vergent folds. Although metamorphic grade is generally low, in localized areas the cleavage planes contain white micas, whose petrologic and isotopic characteristics indicate that they crystallized during fabric formation. 40Ar/39Ar dating of the white micas yield a metamorphic age of ~400 Ma (Early Devonian). This is evidence for a south-directed structural event which is contemporaneous with Caledonian deformation in East Greenland and Svalbard. Stratigraphicaly, the basement consists of a diverse package of highly deformed marine clastic sediments, and a thick section of basaltic to andesitic flows and volcaniclastic rocks, the Whale Mountain volcanics, which have a sharp southern contact but grade northward and upwards into the clastic rocks. All units are metamorphosed to lower greenschist facies. We are currently investigating the age and geochemical characteristics of the Whale Mountain volcanics to determine their tectonic affinity and role in the assemblage of the North Slope block of Northern Alaska.

  19. Alaska School District Cost Study Update

    ERIC Educational Resources Information Center

    Tuck, Bradford H.; Berman, Matthew; Hill, Alexandra

    2005-01-01

    The Legislative Budget and Audit Committee of the Alaska Legislature has asked The Institute of Social and Economic Research (ISER) at the University of Alaska Anchorage to make certain changes and adjustments to the Geographic Cost of Education Index (GCEI) that the American Institutes for Research (AIR) constructed and reported on in Alaska…

  20. Bill Demmert and Native Education in Alaska

    ERIC Educational Resources Information Center

    Barnhardt, Ray

    2011-01-01

    This article describes the influences of William Demmert's formative years growing up in Alaska and his years as an educator of Native American students upon his career in Native education policy. It focuses on Alaska Native education during a ten-year period between 1980 and 1990 during which time he served as the director of the Center for…

  1. Women's Legal Rights in Alaska. Reprint.

    ERIC Educational Resources Information Center

    Tatter, Sue Ellen; Saville, Sandra K.

    This publication is intended to help women in Alaska learn about their legal rights. Some of the information is of a general nature and will be of interest to women in other states. Some of the laws and resources are relevant to Alaska only. The publication can serve as a model to other states wanting to develop a resource to inform women about…

  2. Culturally Responsive Guidelines for Alaska Public Libraries.

    ERIC Educational Resources Information Center

    Alaska Univ., Fairbanks. Alaska Native Knowledge Network.

    These guidelines are predicated on the belief that culturally appropriate service to indigenous peoples is a fundamental principle of Alaska public libraries. While the impetus for developing the guidelines was service to the Alaska Native community, they can also be applied to other cultural groups. A culturally responsive library environment is…

  3. Building a Workforce Development System in Alaska

    ERIC Educational Resources Information Center

    Spieker, Sally

    2004-01-01

    The Alaska Human Resources Investment Council developed a blueprint to guide a system that is needs-driven, accessible, interconnected, accountable, sustainable, and has collaborative governance. Vocational Technical Education Providers (VTEP) representing secondary education, technical schools, proprietary institutions, the University of Alaska,…

  4. Distance Learning in Alaska's Rural Schools.

    ERIC Educational Resources Information Center

    Bramble, William J.

    1986-01-01

    The distance education and instructional technology projects that have been undertaken in Alaska over the last decade are detailed in this paper. The basic services offered by the "Learn Alaska Network" are described in relation to three user groups: K-12 education; postsecondary education; and general public education and information. The audio…

  5. 77 FR 16314 - Alaska Disaster #AK-00024

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-20

    ... ADMINISTRATION Alaska Disaster AK-00024 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of Alaska dated 03/13/2012... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409...

  6. 78 FR 39822 - Alaska Disaster #AK-00028

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... ADMINISTRATION Alaska Disaster AK-00028 AGENCY: U.S. Small Business Administration. ACTION: Notice SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Alaska (FEMA-4122-DR... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409...

  7. 75 FR 43199 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... approving the conveyance of surface estate for certain lands to Beaver Kwit'chin Corporation, pursuant to... Doyon, Limited when the surface estate is conveyed to Beaver Kwit'chin Corporation. The lands are in the vicinity of Beaver, Alaska, and are located in: Fairbanks Meridian, Alaska T. 16 N., R. 1 E., Secs. 1 to...

  8. 77 FR 21802 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-11

    ... Kongnikilnomuit Yuita Corporation. The lands are in the vicinity of Bill Moore's Slough, Alaska, and are located... conveyance pursuant to the Alaska Native Claims Settlement Act (43 U.S.C. 1601, et seq). The subsurface... hours. Jennifer Noe, Land Law Examiner, Land Transfer Adjudication II Branch. BILLING CODE 4310-JA-P...

  9. Alaska Head Start. Annual Report for 1998.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Community and Regional Affairs, Juneau.

    This annual report details the accomplishments of the Alaska Head Start Program for fiscal year 1998. The report begins with a graphic presentation of the locations of Alaska Head Start programs and a table delineating the administrative and program partners of Head Start, its service population, eligibility requirements, funding sources, service…

  10. Facts & Figures about Education in Alaska, 1992.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau.

    This collection of tables presents selected facts and figures about education in Alaska. General and district school information about Alaska's 469 public schools in 54 districts and its 276 private and denominational schools is followed by tables of general student information, including average daily membership, enrollment, graduates, and…

  11. Integrating Intercultural Education: The Anchorage Alaska Experience.

    ERIC Educational Resources Information Center

    Fenton, Ray

    The desire for students to understand and respect each other is a primary motivation for the effort to integrate multicultural education into all aspects of the Anchorage School District (Alaska) curriculum. The Anchorage curriculum emphasizes the cultural heritage of Alaska Natives, other resident ethnic groups and Pacific Rim cultures. In recent…

  12. Viewpoints: Reflections on the Principalship in Alaska.

    ERIC Educational Resources Information Center

    Hagstrom, David A., Ed.

    In this collection, 32 Alaskan principals, retired principals, assistant principals, and principals-to-be share their experiences as administrators and reflect on their feelings about the nature of the work and about schooling issues in Alaska. Nine of the writings were selected from "Totem Tales," the newsletter of Alaska's Association of…

  13. Joint Science Education Project: Learning about polar science in Greenland

    NASA Astrophysics Data System (ADS)

    Foshee Reed, Lynn

    2014-05-01

    The Joint Science Education Project (JSEP) is a successful summer science and culture opportunity in which students and teachers from the United States, Denmark, and Greenland come together to learn about the research conducted in Greenland and the logistics involved in supporting the research. They conduct experiments first-hand and participate in inquiry-based educational activities alongside scientists and graduate students at a variety of locations in and around Kangerlussuaq, Greenland, and on the top of the ice sheet at Summit Station. The Joint Committee, a high-level forum involving the Greenlandic, Danish and U.S. governments, established the Joint Science Education Project in 2007, as a collaborative diplomatic effort during the International Polar Year to: • Educate and inspire the next generation of polar scientists; • Build strong networks of students and teachers among the three countries; and • Provide an opportunity to practice language and communication skills Since its inception, JSEP has had 82 student and 22 teacher participants and has involved numerous scientists and field researchers. The JSEP format has evolved over the years into its current state, which consists of two field-based subprograms on site in Greenland: the Greenland-led Kangerlussuaq Science Field School and the U.S.-led Arctic Science Education Week. All travel, transportation, accommodations, and meals are provided to the participants at no cost. During the 2013 Kangerlussuaq Science Field School, students and teachers gathered data in a biodiversity study, created and set geo- and EarthCaches, calculated glacial discharge at a melt-water stream and river, examined microbes and tested for chemical differences in a variety of lakes, measured ablation at the edge of the Greenland Ice Sheet, and learned about fossils, plants, animals, minerals and rocks of Greenland. In addition, the students planned and led cultural nights, sharing food, games, stories, and traditions of

  14. Natural variability of Greenland climate, vegetation, and ice volume during the past million years.

    PubMed

    de Vernal, Anne; Hillaire-Marcel, Claude

    2008-06-20

    The response of the Greenland ice sheet to global warming is a source of concern notably because of its potential contribution to changes in the sea level. We demonstrated the natural vulnerability of the ice sheet by using pollen records from marine sediment off southwest Greenland that indicate important changes of the vegetation in Greenland over the past million years. The vegetation that developed over southern Greenland during the last interglacial period is consistent with model experiments, suggesting a reduced volume of the Greenland ice sheet. Abundant spruce pollen indicates that boreal coniferous forest developed some 400,000 years ago during the "warm" interval of marine isotope stage 11, providing a time frame for the development and decline of boreal ecosystems over a nearly ice-free Greenland. PMID:18566284

  15. Sexual and reproductive health in Greenland: evaluation of implementing sexual peer-to-peer education in Greenland (the SexInuk project)

    PubMed Central

    Homøe, Anne-Sophie; Knudsen, Ane-Kersti Skaarup; Nielsen, Sigrid Brisson; Grynnerup, Anna Garcia-Alix

    2015-01-01

    Background For decades, the rates of sexually transmitted infections (STIs), such as gonorrhoea, chlamydia and syphilis, have increased in Greenland, especially within the young age groups (15–29 years). From 2006 to 2013, the number of abortions has been consistent with approximately 800–900 abortions per year in Greenland, which is nearly as high as the total number of births during the same period. Previous studies in Greenland have reported that knowledge about sexual health is important, both as prevention and as facilitator to stop the increasing rates of STIs. A peer-to-peer education programme about sexual health requires adaption to cultural values and acceptance among the population and government in order to be sustainable. Objective Formative evaluation of a voluntary project (SexInuk), in relation to peer-to-peer education with focus on sexual health. Two workshops were conducted in Nuuk, Greenland, to recruit Greenlandic students. Design Qualitative design with focus group interviews (FGIs) to collect qualitative feedback on feasibility and implementation of the project. Supplemented with a brief questionnaire regarding personal information (gender, age, education) and questions about the educational elements in the SexInuk project. Eight Greenlandic students, who had completed one or two workshops, were enrolled. Results The FGIs showed an overall consensus regarding the need for improving sexual health education in Greenland. The participants requested more voluntary educators, to secure sustainability. The articulation of taboo topics in the Greenlandic society appeared very important. The participants suggested more awareness by promoting the project. Conclusion Cultural values and language directions were important elements in the FGIs. To our knowledge, voluntary work regarding peer-to-peer education and sexual health has not been structurally evaluated in Greenland before. To achieve sustainability, the project needs educators and financial

  16. Native Pathways to Education: Alaska Rural Systemic Initiative.

    ERIC Educational Resources Information Center

    Alaska Univ., Fairbanks.

    The Alaska Federation of Natives, in cooperation with the University of Alaska, received funding to implement the Alaska Rural Systemic Initiative (AKRSI). Over a 5-year period (1995-2000), AKRSI initiatives are systematically documenting the indigenous knowledge systems of Alaska Native people and developing educational policies and practices…

  17. Infant Mortality and American Indians/Alaska Natives

    MedlinePlus

    ... Heath & Mortality Infant Mortality and American Indians/Alaska Natives American Indian/Alaska Natives have 1.5 times the ... Cause of Death (By rank) # American Indian/Alaska Native Deaths American Indian/Alaska Native Death Rate #Non- Hispanic White ...

  18. The Alaska State Writing Consortium: The First Five Years.

    ERIC Educational Resources Information Center

    Parson, Gail

    This booklet documents the first 5 years of the Alaska State Writing Consortium, an association made up of 45 Alaska school districts, the Alaska Department of Education, and the University of Alaska. The Consortium, which oversees the organization and implementation of teacher training programs in writing and the teaching of writing, has five…

  19. Age of Magmatism and Eurekan Deformation in North Greenland

    NASA Astrophysics Data System (ADS)

    Tegner, Christian; Storey, Michael; Holm, Paul M.; Thorarinsson, Sigurjon; Knudsen, Mads F.

    2014-05-01

    The alpine mountains of Northernmost Greenland are composed of Phanerozoic sediments and volcanic rocks that make up a broadly East-West striking orogenic belt. The major components include: 1) Cambrian-Devonian sediments deposited in the Franklinian Basin; 2) Ellesmerian (365-345 Ma) deformation of these sediments into a fold belt; 3) renewed extension and deposition of Carboniferous-Cretaceous sediments and Cretaceous-Paleogene volcanic rocks of the Kap Washington Group; and 4) Eurekan deformation of sediments and volcanic rocks. We present results of 40Ar-39Ar, U-Pb and Rb-Sr dating of volcanic rocks of the Kap Washington Group. This volcanic succesion is part of the High Arctic Large Igneous Province, exceeds 5 km in thickness, and is composed of bimodal alkaline flows, agglomerates and ignimbrites including peralkaline compositions typical of continental rifts such as the East African Rift. Based on zircon U-Pb and amphibole 40Ar-39Ar ages most volcanics were emplaced at 71-68 Ma, but activity continued down to 61 Ma. A thermal resetting age of 49-47 Ma is also identified in 40Ar-39Ar whole-rock data for trachyte flows. Patch perthite feldspars and coeval resetting of Rb-Sr isotopes by hydrothermal fluids provide further support for thermal overprinting, interpreted as a result of Eurekan compressional tectonism. It is striking that North Greenland volcanism terminated at about the same time (c. 61 Ma) as magmatism in the North Atlantic Large Igneous Province began. We suggest that this was a corollary of a change from extensional to compressional tectonism in the High Arctic. In the period when Greenland moved together with Eurasia (>60 Ma), the separation from North America resulted in rift-related alkaline magmatism in the High Arctic. When Greenland subsequently moved as a separate plate (60-35 Ma), overlapping spreading on both sides pushed it northwards and volcanism in the High Arctic stopped due to compression. Evaluation of plate kinematic models

  20. An integrated geophysical investigation of Greenland's tectonic history

    NASA Astrophysics Data System (ADS)

    Roman, Daniel Robert

    A new model for the crustal evolution of the Labrador Sea region of southwestern Greenland (58.7--61.9°N and 48--53°W) was developed from gravity-derived Moho estimates and lithologic and geologic features interpreted from correlative geopotential anomalies, and recent seismic surveys [Chian and Louden, 1994; Chian et al., 1995a, Chian et al., 1995b; Chalmers and Laursen, 1995]. Previous kinematic models [Srivastava, 1978; Srivastava and Tapscott, 1986; Roest and Srivastava, 1989] suggested that the opening of the Labrador Sea caused a counterclockwise rotation of Greenland from ca. 92 to 36 Ma as a part of the opening of the North Atlantic Ocean. These models were based on interpretation of a 150 km wide zone of crust off of the coasts of Greenland and Labrador as oceanic crust with continuous magnetic isochrons through anomaly 33. The structural implications of the gravity-derived Moho and crustal density models challenge this interpretation. Instead, this region is interpreted a combination of rifted-continental and transitional crust. The correlation analysis of free-air gravity and magnetic anomalies determined that rocks within this 150 km zone were more characteristic of rifted-continental or transitional crust, and this was further supported by the results of seismic surveys [Chian and Louden, 1994; Chian et al., 1995a; 1995b; Chalmers and Laursen, 19951. The linear magnetic anomalies interpreted as isochrons 31 and 33 by Roest and Srivastava [1995] were interpreted as serpentinization along the crustal rupture and delamination surfaces or along the base of regional-scale half-grabens. The revised model postulates that the rotational opening of the Canada Basin from 135 to 118 Ma induced a counterclockwise rotation of Greenland, which extended and thinned the Archean crust between Greenland and Labrador. This weakened crust was thus well disposed to rifting when the North Atlantic rift system propagated northward into the region at about 90 Ma. Slow

  1. Metalliferous lode deposits of Alaska

    USGS Publications Warehouse

    Berg, Henry C.; Cobb, Edward Huntington

    1967-01-01

    This report summarizes from repoAs of Federal and State agencies published before August 31, 1965, the geology of Alaska's metal-bearing lodes, including their structural or stratigraphic control, host rock, mode of origin, kinds of .Q minerals, grade, past production, and extent of exploration. In addition, the lists of mineral occurrences that accompany the 35 mineral-deposit location maps constitute an inventory of the State's known lodes. A total of 692 localities where m&alliferous deposits have been found are shown on the maps. The localities include 1,739 mines, prospects, and reported occurrences, of which 821 are described individually or otherwise cited in the text.

  2. 78 FR 57106 - Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-17

    ... Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment 95 to the Fishery Management Plan for... implement Amendment 95 to the Fishery Management Plan for Groundfish of the Gulf of Alaska (FMP). This proposed action would modify halibut prohibited species catch (PSC) management in the Gulf of Alaska...

  3. Diachronous retreat of the Greenland ice sheet during the last deglaciation

    NASA Astrophysics Data System (ADS)

    Sinclair, G.; Carlson, A. E.; Mix, A. C.; Lecavalier, B. S.; Milne, G.; Mathias, A.; Buizert, C.; DeConto, R.

    2016-08-01

    The last deglaciation is the most recent interval of large-scale climate change that drove the Greenland ice sheet from continental shelf to within its present extent. Here, we use a database of 645 published 10Be ages from Greenland to document the spatial and temporal patterns of retreat of the Greenland ice sheet during the last deglaciation. Following initial retreat of its marine margins, most land-based deglaciation occurred in Greenland following the end of the Younger Dryas cold period (12.9-11.7 ka). However, deglaciation in east Greenland peaked significantly earlier (13.0-11.5 ka) than that in south Greenland (11.0-10 ka) or west Greenland (10.5-7.0 ka). The terrestrial deglaciation of east and south Greenland coincide with adjacent ocean warming. 14C ages and a recent ice-sheet model reconstruction do not capture this progression of terrestrial deglacial ages from east to west Greenland, showing deglaciation occurring later than observed in 10Be ages. This model-data misfit likely reflects the absence of realistic ice-ocean interactions. We suggest that oceanic changes may have played an important role in driving the spatial-temporal ice-retreat pattern evident in the 10Be data.

  4. Ocean Melting Greenland (OMG) bathymetric survey of northwest Greenland and implications for the recent evolution of its glaciers

    NASA Astrophysics Data System (ADS)

    Wood, M.; Rignot, E. J.; Willis, J. K.; Fenty, I. G.

    2015-12-01

    Oceans Melting Greenland (OMG) is a five-year Earth Ventures Suborbital Mission funded by NASA to investigate the role of the oceans in ice loss around the margins of the Greenland Ice Sheet, which includes measurements of seafloor bathymetry from multibeam surveys and airborne gravity, glacier surface elevation from high-frequency radar interferometry, and temperature/salinity/depth from vessels and airborne-dropped probes. Here, we describe the results of the 2016 bathymetry survey of northwest Greenland that took place in the summer of 2015: july 22-August 19 and Sept 2-Sept 16 spanning from Ilulissat to Thule AFB in north Greenland, and to be complemented by a survey of southeast Greenland in 2016. We deployed a multibeam Reson 7160 with 512 beams installed on the hull of the Cape Race vessel, with enhanced capabilities for fjord wall and ice face mapping. The survey tracks were optimized based on the IBCAO3 database, recent cruises, airborne gravity data collected by NASA Operation IceBridge which indicated the presence of troughs, bed topography mapped inland using a mass conservation approach, the spatial distribution of ice discharge to locate the largest outlets and maximizing the number of major fjords sampled during the survey, with the goal to identify all troughs that are major pathways for subsurface ocean heat, and constrain as many glacier ice front thickness as permitted by time and the practicality of navigating the ice-choked fjords. The data reveal many deep, U-shaped, submarine valleys connected to the glaciers, intercut with sills and over deepened in narrower passages where former glaciers and ice streams merged into larger units; as well as fjords ending in shallow plateaus with glaciers in retreated positions. The presence of warm, salty water of Atlantic origin (AW) in the fjords is documented using CTD. Some glaciers sit on shallow plateaus in cold, fresh polar waters (PW) at the end of deep fjords, while others are deeper and standing in

  5. The Changing Albedo of the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Human, J. M.; Box, J. E.

    2009-12-01

    The study evaluates Greenland ice sheet surface albedo sensitivity to surface melt intensity, air pollution, and precipitation using data from the MODIS and MOPITT sensors operating on the NASA Terra satellite 2000-2009. Precipitation rates are simulated by the Polar WRF climate model running in data assimilation mode. Statistical regression facilitates ranking the relative importance of each of the albedo forcings in space and time. Further, quantitative estimates of the albedo sensitivity to its forcing factors are made, for the first time and over the observed inter-annual range. The work investigates regional patterns in detail to quantify melt water production associated with absorbed solar radiation variability. In-situ records are used to evaluate the cloud radiative effect as another important factor of absorbed solar radiation and ice melt. Insight into Greenland ice sheet melt-precipitation-pollution-albedo feedback is gained, key in better understanding the mass balance response of the ice sheet to future climate change.

  6. A Comparison of Geoid Undulations for West Central Greenland

    NASA Technical Reports Server (NTRS)

    Roman, Daniel R.; Csatho, Beata; Jezek, Kenneth C.; Thomas, Robert H.; Krabill, William B.; vonFrese, Ralph R. B.; Forsberg, Rene

    1997-01-01

    The accuracy of a new local gravity field model, GEOID94A, is examined at a site on the western Greenland ice sheet. The model, developed by the Danish National Survey and Cadastre, incorporates several new gravity data sets including an extensive amount of airborne gravity data. Model-derived geoid undulations were compared to independently determined undulations found by differencing the elevations from Global Positioning System controlled airborne laser altimetry and optical leveling surveys. Differences between the two sets of undulations were less than +/- 6 cm RMS. The comparison improved (+/- 5 cm RMS) when GEOID94A undulations were adjusted by local gravity observations also acquired at the site. Our comparisons demonstrate that GEOID94A adequately models the long to intermediate wavelengths of the gravity field. We conclude that GEOID94A constitutes a reliable reference model for studies of Greenland's gravity field.

  7. Conditioning instabilities of the Greenland Sea. Master's thesis

    SciTech Connect

    Olson, J.M.

    1992-09-01

    This is an examination of the open ocean deep water formation process of the Greenland Sea and how it is effected by the depth dependent thermal expansion coefficient. It is hypothesized that free convection associated with parcel instability is possible because of the increase in the thermal expansion coefficient with pressure in conjunction with requisite ambient temperature and salinity profiles. Based on the depth dependence of the thermal expansion coefficient, a neutral profile model for parcel instability was formulated and the effects on mixed layer dynamics were investigated. in situ profiles for the wintertime Greenland Sea were examined for potential parcel instabilities. It was shown that only small surface salinity increases associated with freezing could lead to deep penetrative convection. Finally, an analysis was performed for regions of low stability using climatology from the Levitus data set to determine regions most likely for deep convection.

  8. Greenland precipitation estimates from the atmospheric moisture budget

    SciTech Connect

    Robasky, F.M.; Bromwich, D.H.

    1994-11-15

    Eight radiosonde stations surrounding Greenland at an average separation of 750 km are used to compute the atmospheric moisture budget. Radiosonde data were available from 1963-89, but were not used for 1963-79 due to insufficient data coverage which likely resulted in a major underestimation of large moisture inflow events. There is a mean annual inflow of moisture to the atmospheric volume over Greenland through its southeast and southwest sectors, and outflow to the northeast. Moisture convergences, equivalent to precipitation minus evaporation, yield an areal average of 32 cm yr{sup {minus}1} of water equivalent; they also show high inter- and intra-annual agreement with earlier modeled precipitation estimates found by the authors and serve as further confirmation of their modeling results. The time-averaged eddy component accounts for 90% of the total moisture convergence, reflecting the dominant contribution of precipitation from synoptic-scale cyclones. 20 refs., 5 figs.

  9. RadarSAT And Snow Characteristics At Greenland Summit

    NASA Astrophysics Data System (ADS)

    Manninen, Terhikki; Lahtinen, Panu; Anttila, Kati; Riihela, Aku

    2013-12-01

    The RASCALS (Radiation, Snow Characteristics and Albedo at Summit) campaign [1] was carried out at the Greenland Summit camp research station during June - July 2010. The collection of surface roughness, dielectric constant and density profiles of snow were carried out concurrently with snow albedo and bidirectional reflectance distribution function (BRDF) measurements. Polarimetric interferometry of Radarsat-2 quad pol fine beam images is used to study the snow surface anisotropy at Summit, Greenland. Various methods of determining the polarimetric coherence are tested and the results are compared with the in situ surface roughness results, which show a clear anisotropy varying with time. In addition, surface backscattering modelling is used to check the fraction of the surface backscattering.

  10. Deformation of Eemian and Glacial ice at NEEM, Greenland

    NASA Astrophysics Data System (ADS)

    Keegan, Kaitlin; Dahl-Jensen, Dorthe; Montagnat, Maurine; Weikusat, Ilka; Kipfstuhl, Sepp

    2015-04-01

    New findings from deep Greenland ice cores and airborne radio echo sounding (RES) images show that basal ice flow is very unstable, and a basal layer of disturbed ice is often observed. At NEEM, Greenland this folding occurs at the boundary between the Eemian and glacial ice regimes, suggesting that differences in physical properties of the ice play a role in the disturbance. Past work in metallurgy (Burke, 1957) and ice (Hammer et al., 1978; Langway et al., 1988; Dahl-Jensen et al., 1997), suggests that impurity content controls grain evolution, and therefore deformation, which we hypothesize to be analogous to the differences in ice flow seen deep in the NEEM ice core. Here we present results of fabric, grain size, impurity content, and deformation studies from samples above and below this unstable boundary in the ice sheet.

  11. Past temperatures directly from the greenland ice sheet

    PubMed

    Dahl-Jensen; Mosegaard; Gundestrup; Clow; Johnsen; Hansen; Balling

    1998-10-01

    A Monte Carlo inverse method has been used on the temperature profiles measured down through the Greenland Ice Core Project (GRIP) borehole, at the summit of the Greenland Ice Sheet, and the Dye 3 borehole 865 kilometers farther south. The result is a 50, 000-year-long temperature history at GRIP and a 7000-year history at Dye 3. The Last Glacial Maximum, the Climatic Optimum, the Medieval Warmth, the Little Ice Age, and a warm period at 1930 A.D. are resolved from the GRIP reconstruction with the amplitudes -23 kelvin, +2.5 kelvin, +1 kelvin, -1 kelvin, and +0.5 kelvin, respectively. The Dye 3 temperature is similar to the GRIP history but has an amplitude 1.5 times larger, indicating higher climatic variability there. The calculated terrestrial heat flow density from the GRIP inversion is 51.3 milliwatts per square meter. PMID:9765146

  12. Recent warming at Summit, Greenland: Global context and implications

    NASA Astrophysics Data System (ADS)

    McGrath, Daniel; Colgan, William; Bayou, Nicolas; Muto, Atsuhiro; Steffen, Konrad

    2013-05-01

    at Summit, Greenland suggest that the annual mean near-surface air temperature increased at 0.09 ± 0.01°C/a over the 1982-2011 climatology period. This rate of warming, six times the global average, places Summit in the 99th percentile of all globally observed warming trends over this period. The rate of warming at Summit is increasing over time. During the instrumental period (1987-2011), warming has been greatest in the winter season, although the implications of summer warming are more acute. The annual maximum elevation of the equilibrium line and dry snow line has risen at 44 and 35 m/a over the past 15 and 18 years, respectively. Extrapolation of this observed trend now suggests, with 95% confidence intervals, that the dry snow facies of the Greenland Ice Sheet will inevitably transition to percolation facies. There is a 50% probability of this transition occurring by 2025.

  13. Paleofluvial landscape inheritance for Jakobshavn Isbræ catchment, Greenland

    NASA Astrophysics Data System (ADS)

    Cooper, M. A.; Michaelides, K.; Siegert, M. J.; Bamber, J. L.

    2016-06-01

    Subglacial topography exerts strong controls on glacier dynamics, influencing the orientation and velocity of ice flow, as well as modulating the distribution of basal waters and sediment. Bed geometry can also provide a long-term record of geomorphic processes, allowing insight into landscape evolution, the origin of which may predate ice sheet inception. Here we present evidence from ice-penetrating radar data for a large dendritic drainage network, radiating inland from Jakobshavn Isbræ, Greenland's largest outlet glacier. The size of the drainage basin is ˜450,000 km2 and accounts for about 20% of the total land area of Greenland. Topographic and basin morphometric analyses of an isostatically uplifted (ice-free) bedrock topography suggests that this catchment predates ice sheet initiation and has likely been instrumental in controlling the location and form of the Jakobshavn ice stream, and ice flow from the deep interior to the margin, now and over several glacial cycles.

  14. Large Fluctuations in Speed on Jakobshavn Isbrae, Greenland

    NASA Technical Reports Server (NTRS)

    Joughin, Ian; Abdalati, Waleed; Fahnestock, Mark

    2003-01-01

    We have assembled an 18-year velocity record for Jakobshavn Isbrae, Greenland. From a 1985 speed of approx. 7000 m/yr, the glacier had slowed by approx. 1000 m/ yr in 1992, which coincided with independently observed thickening in the early 1990s . The glacier then sped up by approx. 4000 m/yr between 1997 and 2000, during which time other measurements show rapid thinning . From 2000 to 2003, the glacier s floating ice tongue almost entirely disintegrated, as speed increased to 12,600 m/yr. If the retreat of the ice tongue caused the acceleration, then similar losses of floating ice tongues since the Little Ice Age may explain the current rapid thinning observed for many of Greenland s outlet glaciers.

  15. Micrometeorite pre-solar diamonds from Greenland cryoconite?

    NASA Technical Reports Server (NTRS)

    Yates, P. D.

    1993-01-01

    An acid-resistant residue prepared from Greenland cryoconite has been investigated to determine whether the micrometeorite component within the cryoconite contains pre-solar material analogous to that found in primitive chondritic meteorites. The residue has been analyzed for carbon content and stable isotopic comparison, by electron probe micro-analysis (EPMA) for major element chemistry and then by a combination of X-ray diffraction (XRD) and transmission electron microscopy (TEM) to elucidate the structure of any constituent mineral phases. The cryoconite sample, which was collected ca. 25 km inland of the ice margin at the latitude of Sondre Stromfjord on the west coast of Greenland, was processed following procedures used on bulk meteorite samples for the isolation of pre-solar dust components.

  16. North Atlantic warming and the retreat of Greenland's outlet glaciers.

    PubMed

    Straneo, Fiammetta; Heimbach, Patrick

    2013-12-01

    Mass loss from the Greenland ice sheet quadrupled over the past two decades, contributing a quarter of the observed global sea-level rise. Increased submarine melting is thought to have triggered the retreat of Greenland's outlet glaciers, which is partly responsible for the ice loss. However, the chain of events and physical processes remain elusive. Recent evidence suggests that an anomalous inflow of subtropical waters driven by atmospheric changes, multidecadal natural ocean variability and a long-term increase in the North Atlantic's upper ocean heat content since the 1950s all contributed to a warming of the subpolar North Atlantic. This led, in conjunction with increased runoff, to enhanced submarine glacier melting. Future climate projections raise the potential for continued increases in warming and ice-mass loss, with implications for sea level and climate.

  17. Black carbon concentration in a Greenland Dye-3 ice core

    SciTech Connect

    Chylek, P.; Johnson, B.; Wu, Hong )

    1992-10-01

    We have determined the black carbon concentration in Greenland Dye-3 ice core samples covering the time period from about 3380 to 100 years before present. The average concentration found is 1.53 microg of black carbon per 1 kg of ice. We have found significantly lower black carbon concentrations during the time period from 750 to 100 years before present connected possibly with the Little Ice Age and corresponding changes in atmospheric general circulation patterns and black carbon sources. 18 refs.

  18. The East Greenland Coastal Current: Structure, variability, and forcing

    NASA Astrophysics Data System (ADS)

    Sutherland, David A.; Pickart, Robert S.

    2008-07-01

    The subtidal circulation of the southeast Greenland shelf is described using a set of high-resolution hydrographic and velocity transects occupied in summer 2004. The main feature is the East Greenland Coastal Current (EGCC), a low-salinity, high-velocity jet with a wedge-shaped hydrographic structure characteristic of other surface buoyancy-driven currents. The EGCC was observed along the entire Greenland shelf south of Denmark Strait, while the transect north of the strait showed only a weak shelf flow. This observation, in conjunction with water mass considerations and other supporting evidence, suggests that the EGCC is an inner branch of the East Greenland Current (EGC) that forms south of Denmark Strait. It is argued that bathymetric steering is the most likely reason why the EGC apparently bifurcates at this location. Repeat sections occupied at Cape Farewell between 1997 and 2004 show that the alongshelf wind stress can have an influence on the structure and strength of the EGCC and EGC on timescales of 2-3 days. Accounting for the wind-induced effects, the volume transport of the combined EGCC/EGC system is roughly constant (∼2 Sv) over the study domain, from 68°N to Cape Farewell near 60°N. The corresponding freshwater transport increases by roughly 60% over this distance (59-96 mSv, referenced to a salinity of 34.8). This trend is consistent with a simple freshwater budget of the EGCC/EGC system that accounts for meltwater runoff, melting sea-ice and icebergs, and net precipitation minus evaporation.

  19. Surface-atmosphere decoupling limits accumulation at Summit, Greenland.

    PubMed

    Berkelhammer, Max; Noone, David C; Steen-Larsen, Hans Christian; Bailey, Adriana; Cox, Christopher J; O'Neill, Michael S; Schneider, David; Steffen, Konrad; White, James W C

    2016-04-01

    Despite rapid melting in the coastal regions of the Greenland Ice Sheet, a significant area (~40%) of the ice sheet rarely experiences surface melting. In these regions, the controls on annual accumulation are poorly constrained owing to surface conditions (for example, surface clouds, blowing snow, and surface inversions), which render moisture flux estimates from myriad approaches (that is, eddy covariance, remote sensing, and direct observations) highly uncertain. Accumulation is partially determined by the temperature dependence of saturation vapor pressure, which influences the maximum humidity of air parcels reaching the ice sheet interior. However, independent proxies for surface temperature and accumulation from ice cores show that the response of accumulation to temperature is variable and not generally consistent with a purely thermodynamic control. Using three years of stable water vapor isotope profiles from a high altitude site on the Greenland Ice Sheet, we show that as the boundary layer becomes increasingly stable, a decoupling between the ice sheet and atmosphere occurs. The limited interaction between the ice sheet surface and free tropospheric air reduces the capacity for surface condensation to achieve the rate set by the humidity of the air parcels reaching interior Greenland. The isolation of the surface also acts to recycle sublimated moisture by recondensing it onto fog particles, which returns the moisture back to the surface through gravitational settling. The observations highlight a unique mechanism by which ice sheet mass is conserved, which has implications for understanding both past and future changes in accumulation rate and the isotopic signal in ice cores from Greenland. PMID:27386509

  20. The Nitrate Content of Greenland Ice and Solar Activity

    NASA Astrophysics Data System (ADS)

    Kocharov, G. E.; Kudryavtsev, I. V.; Ogurtsov, M. G.; Sonninen, E.; Jungner, H.

    2000-12-01

    Past solar activity is studied based on analysis of data on the nitrate content of Greenland ice in the period from 1576 1991. Hundred-year (over the entire period) and quasi-five-year (in the middle of the 18th century) variations in the nitrate content are detected. These reflect the secular solar-activity cycle and cyclicity in the flare activity of the Sun.

  1. Ice Core Records of Recent Northwest Greenland Climate

    NASA Astrophysics Data System (ADS)

    Osterberg, E. C.; Wong, G. J.; Ferris, D.; Lutz, E.; Howley, J. A.; Kelly, M. A.; Axford, Y.; Hawley, R. L.

    2014-12-01

    Meteorological station data from NW Greenland indicate a 3oC temperature rise since 1990, with most of the warming occurring in fall and winter. According to remote sensing data, the NW Greenland ice sheet (GIS) and coastal ice caps are responding with ice mass loss and margin retreat, but the cryosphere's response to previous climate variability is poorly constrained in this region. We are developing multi-proxy records (lake sediment cores, ice cores, glacial geologic data, glaciological models) of Holocene climate change and cryospheric response in NW Greenland to improve projections of future ice loss and sea level rise in a warming climate. As part of our efforts to develop a millennial-length ice core paleoclimate record from the Thule region, we collected and analyzed snow pit samples and short firn cores (up to 21 m) from the coastal region of the GIS (2Barrel site; 76.9317o N, 63.1467o W, 1685 m el.) and the summit of North Ice Cap (76.938o N, 67.671o W, 1273 m el.) in 2011, 2012 and 2014. The 2Barrel ice core record has statistically significant relationships with regional spring and fall Baffin Bay sea ice extent, summertime temperature, and annual precipitation. Here we evaluate relationships between the 2014 North Ice Cap firn core glaciochemical record and climate variability from regional instrumental stations and reanalysis datasets. We compare the coastal North Ice Cap record to more inland records from 2Barrel, Camp Century and NEEM to evaluate spatial and elevational gradients in recent NW Greenland climate change.

  2. Surface-atmosphere decoupling limits accumulation at Summit, Greenland

    PubMed Central

    Berkelhammer, Max; Noone, David C.; Steen-Larsen, Hans Christian; Bailey, Adriana; Cox, Christopher J.; O’Neill, Michael S.; Schneider, David; Steffen, Konrad; White, James W. C.

    2016-01-01

    Despite rapid melting in the coastal regions of the Greenland Ice Sheet, a significant area (~40%) of the ice sheet rarely experiences surface melting. In these regions, the controls on annual accumulation are poorly constrained owing to surface conditions (for example, surface clouds, blowing snow, and surface inversions), which render moisture flux estimates from myriad approaches (that is, eddy covariance, remote sensing, and direct observations) highly uncertain. Accumulation is partially determined by the temperature dependence of saturation vapor pressure, which influences the maximum humidity of air parcels reaching the ice sheet interior. However, independent proxies for surface temperature and accumulation from ice cores show that the response of accumulation to temperature is variable and not generally consistent with a purely thermodynamic control. Using three years of stable water vapor isotope profiles from a high altitude site on the Greenland Ice Sheet, we show that as the boundary layer becomes increasingly stable, a decoupling between the ice sheet and atmosphere occurs. The limited interaction between the ice sheet surface and free tropospheric air reduces the capacity for surface condensation to achieve the rate set by the humidity of the air parcels reaching interior Greenland. The isolation of the surface also acts to recycle sublimated moisture by recondensing it onto fog particles, which returns the moisture back to the surface through gravitational settling. The observations highlight a unique mechanism by which ice sheet mass is conserved, which has implications for understanding both past and future changes in accumulation rate and the isotopic signal in ice cores from Greenland. PMID:27386509

  3. Lively Earthquake Activity in North-Eastern Greenland

    NASA Astrophysics Data System (ADS)

    Larsen, Tine B.; Dahl-Jensen, Trine; Voss, Peter H.

    2016-04-01

    The seismograph at the Danish military outpost, Station Nord (NOR) in North East Greenland, records many regional/local earthquakes every day. Most of these events originate at the Arctic plate boundary between the Eurasian and the North American plates. The plate boundary has a particularly active segment approximately 200 km from the seismograph. Additionally we find a seismically very active region 20-30 km from NOR on the Kronprins Christian Land peninsula. The BB seismograph at NOR was installed in 2002 and later upgraded with real-time telemetry as part of the GLISN-project. Since late 2013 data from NOR have been included in routine processing at GEUS. Phase readings on some of the older data, primarily 2002-2003, have been carried out previously in connection with other projects. As a result, phase readings for more than 6000 local events, recorded exclusively at NOR, were found in the GEUS data base. During the years 2004 to 2007 four locations were occupied by temporary BB seismographs on the North coast of Greenland as part of the Law of the Sea preparatory work. Data from these stations have not previously been analyzed for local and regional events. In this study we combine the recordings from NOR with phase readings from the temporary seismographs in Northern Greenland. The local events on Kronprins Christian Land range in magnitude from less than 2 to a 4.8 event widely recorded in the region and felt by the personnel at Station Nord on August 30, 2005. Station Nord is located in the seismically most active region of Greenland.

  4. Hyperspectral surveying for mineral resources in Alaska

    USGS Publications Warehouse

    Kokaly, Raymond F.; Graham, Garth E.; Hoefen, Todd M.; Kelley, Karen D.; Johnson, Michaela R.; Hubbard, Bernard E.

    2016-07-07

    Alaska is a major producer of base and precious metals and has a high potential for additional undiscovered mineral resources. However, discovery is hindered by Alaska’s vast size, remoteness, and rugged terrain. New methods are needed to overcome these obstacles in order to fully evaluate Alaska’s geology and mineral resource potential. Hyperspectral surveying is one method that can be used to rapidly acquire data about the distributions of surficial materials, including different types of bedrock and ground cover. In 2014, the U.S. Geological Survey began the Alaska Hyperspectral Project to assess the applicability of this method in Alaska. The primary study area is a remote part of the eastern Alaska Range where porphyry deposits are exposed. In collaboration with the Alaska Division of Geological and Geophysical Surveys, the University of Alaska Fairbanks, and the National Park Service, the U.S. Geological Survey is collecting and analyzing hyperspectral data with the goals of enhancing geologic mapping and developing methods to identify and characterize mineral deposits elsewhere in Alaska.

  5. Review: groundwater in Alaska (USA)

    USGS Publications Warehouse

    Callegary, J.B.; Kikuchi, C.P.; Koch, J.C.; Lilly, M.R.; Leake, S.A.

    2013-01-01

    Groundwater in the US state of Alaska is critical to both humans and ecosystems. Interactions among physiography, ecology, geology, and current and past climate have largely determined the location and properties of aquifers as well as the timing and magnitude of fluxes to, from, and within the groundwater system. The climate ranges from maritime in the southern portion of the state to continental in the Interior, and arctic on the North Slope. During the Quaternary period, topography and rock type have combined with glacial and periglacial processes to develop the unconsolidated alluvial aquifers of Alaska and have resulted in highly heterogeneous hydrofacies. In addition, the long persistence of frozen ground, whether seasonal or permanent, greatly affects the distribution of aquifer recharge and discharge. Because of high runoff, a high proportion of groundwater use, and highly variable permeability controlled in part by permafrost and seasonally frozen ground, understanding groundwater/surface-water interactions and the effects of climate change is critical for understanding groundwater availability and the movement of natural and anthropogenic contaminants.

  6. Large fluctuations in speed on Greenland's Jakobshavn Isbrae glacier.

    PubMed

    Joughin, Ian; Abdalati, Waleed; Fahnestock, Mark

    2004-12-01

    It is important to understand recent changes in the velocity of Greenland glaciers because the mass balance of the Greenland Ice Sheet is partly determined by the flow rates of these outlets. Jakobshavn Isbrae is Greenland's largest outlet glacier, draining about 6.5 per cent of the ice-sheet area, and it has been surveyed repeatedly since 1991 (ref. 2). Here we use remote sensing data to measure the velocity of Jakobshavn Isbrae between 1992 and 2003. We detect large variability of the velocity over time, including a slowing down from 6,700 m yr(-1) in 1985 to 5,700 m yr(-1) in 1992, and a subsequent speeding up to 9,400 m yr(-1) by 2000 and 12,600 m yr(-1) in 2003. These changes are consistent with earlier evidence for thickening of the glacier in the early 1990s and rapid thinning thereafter. Our observations indicate that fast-flowing glaciers can significantly alter ice discharge at sub-decadal timescales, with at least a potential to respond rapidly to a changing climate. PMID:15577906

  7. Mineralogy and composition of Archean Crust, Greenland: A pilot study

    NASA Technical Reports Server (NTRS)

    Goetz, Alexander F. H.; Curtiss, Brian

    1989-01-01

    The Portable Instant Display and Analysis Spectrometer (PIDAS) was taken to southwestern Greenland to investigate in situ the potential application of AVIRIS to estimate the mineralogy and composition of rocks exposed in Archean terranes. The goal was to determine the feasibility of using a high spectral resolution scanner to find and study pristine rocks, those that have not been altered by subsequent deformation and metamorphism. The application of AVIRIS data to the problems in Greenland is logical. However, before a costly deployment of the U-2 aircraft to Greenland is proposed, this study was undertaken to acquire the spectral data necessary to verify that mineralogical mapping in the environmental conditions found there is possible. Although field conditions were far from favorable, all of the major objectives of the study were addressed. One of the major concerns was that lichens would obscure the rock surfaces. It was found that the spectral signature of the lichens was distinct from the underlying rocks. Thus, a spectrum of a rock outcrop, with its partial cover of lichens, can be un-mixed into rock and lichen components. The data acquired during the course of this study supports the conclusion that areas of pristine Archean crust can be differentiated from that which has experienced low grade alteration associated with Proterizoic faulting.

  8. The Greenland Telescope (GLT): antenna status and future plans

    NASA Astrophysics Data System (ADS)

    Raffin, Philippe; Algaba-Marcosa, Juan Carlos; Asada, Keiichi; Blundell, Raymond; Burgos, Roberto; Chang, Chih-Cheng; Chen, Ming-Tang; Christensen, Robert; Grimes, Paul K.; Han, C. C.; Ho, Paul T. P.; Huang, Yau-De; Inoue, Makoto; Koch, Patrick M.; Kubo, Derek; Leiker, Steve; Liu, Ching-Tang; Martin-Cocher, Pierre; Matsushita, Satoki; Nakamura, Masanori; Nishioka, Hiroaki; Nystrom, George; Paine, Scott N.; Patel, Nimesh A.; Pradel, Nicolas; Pu, Hung-Yi; Shen, H.-Y.; Snow, William; Sridharan, Tirupati K.; Srinivasan, Ranjani; Tong, Edward; Wang, Jackie

    2014-07-01

    The ALMA North America Prototype Antenna was awarded to the Smithsonian Astrophysical Observatory (SAO) in 2011. SAO and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), SAO's main partner for this project, are working jointly to relocate the antenna to Greenland to carry out millimeter and submillimeter VLBI observations. This paper presents the work carried out on upgrading the antenna to enable operation in the Arctic climate by the GLT Team to make this challenging project possible, with an emphasis on the unexpected telescope components that had to be either redesigned or changed. Five-years of inactivity, with the antenna laying idle in the desert of New Mexico, coupled with the extreme weather conditions of the selected site in Greenland have it necessary to significantly refurbish the antenna. We found that many components did need to be replaced, such as the antenna support cone, the azimuth bearing, the carbon fiber quadrupod, the hexapod, the HVAC, the tiltmeters, the antenna electronic enclosures housing servo and other drive components, and the cables. We selected Vertex, the original antenna manufacturer, for the main design work, which is in progress. The next coming months will see the major antenna components and subsystems shipped to a site of the US East Coast for test-fitting the major antenna components, which have been retrofitted. The following step will be to ship the components to Greenland to carry out VLBI

  9. Greenland ice sheet melting during the last interglacial

    NASA Astrophysics Data System (ADS)

    Langebroek, Petra M.; Nisancioglu, Kerim H.

    2016-04-01

    During the last interglacial period (LIG) peak temperatures over Greenland were several degrees warmer than today. The Greenland ice sheet (GIS) retreated causing a global sea-level rise in the order of several meters. Large uncertainties still exist in the exact amount of melt and on the source location of this melt. Here we examine the GIS response to LIG temperature and precipitation patterns using the SICOPOLIS ice sheet model. The LIG climate was simulated by forcing the Norwegian Earth System Model (NorESM) with the appropriate greenhouse gases and orbital settings. The resulting LIG ice volume evolution strongly depends on the chosen value of uncertain model parameters for the ice sheet (e.g. basal sliding parameter, PDD factors, and atmospheric temperature lapse rate). We reduce the uncertainty by evaluating an ensemble of model results against present-day observations of ice sheet size, elevation and stability, together with paleo information from deep ice cores. We find a maximum GIS reduction equivalent to 0.8 to 2.2m of global sea-level rise. In this model set-up most of the melting occurs in southwestern Greenland.

  10. Coastal Greenland air temperature extremes 1890-2010

    NASA Astrophysics Data System (ADS)

    Mernild, Sebastian H.; Hanna, Edward; Cappelen, John

    2013-04-01

    We use observed air temperature data series from fourteen meteorological stations in coastal Greenland (located all around the Greenland Ice Sheet (GrIS)) for 1960-2010, where long-term records for five of the stations extend back to 1890, to illustrate the annual and monthly temporal and spatial distribution of temperature extremes. We find that the 2000s (2001-2010) had the highest number of mean annual air temperature (MAAT) warm extremes, and the 1890s (1891-1900) the highest number of cold extremes. For the 2000s the number of warm extremes was significantly higher by around 50% than the number in the 1940s (the Early Twentieth Century Warm Period): the decade with the second highest occurrence of MAAT warm extremes. Since 1960, based on MAAT the number of cold extremes has decreased on the decadal timescale, while warm extremes have increased leading to a higher occurrence of extremes (cold plus warm extremes): an almost similar pattern occurred on mean monthly and on monthly mean daily maximum and minimum scales. Further, a division of Greenland into east and west sectors shows that the occurrence of cold (warm) extremes was more pronounced in the East than in the West in the 1960s and 1970s (mid-1980s to the 2000s).

  11. Continental ice in Greenland during the Eocene and Oligocene

    NASA Astrophysics Data System (ADS)

    Eldrett, James S.; Harding, Ian C.; Wilson, Paul A.; Butler, Emily; Roberts, Andrew P.

    2007-03-01

    The Eocene and Oligocene epochs (~55 to 23 million years ago) comprise a critical phase in Earth history. An array of geological records supported by climate modelling indicates a profound shift in global climate during this interval, from a state that was largely free of polar ice caps to one in which ice sheets on Antarctica approached their modern size. However, the early glaciation history of the Northern Hemisphere is a subject of controversy. Here we report stratigraphically extensive ice-rafted debris, including macroscopic dropstones, in late Eocene to early Oligocene sediments from the Norwegian-Greenland Sea that were deposited between about 38 and 30million years ago. Our data indicate sediment rafting by glacial ice, rather than sea ice, and point to East Greenland as the likely source. Records of this type from one site alone cannot be used to determine the extent of ice involved. However, our data suggest the existence of (at least) isolated glaciers on Greenland about 20million years earlier than previously documented, at a time when temperatures and atmospheric carbon dioxide concentrations were substantially higher.

  12. Factors Controlling Methane in Arctic Lakes of Southwest Greenland.

    PubMed

    Northington, Robert M; Saros, Jasmine E

    2016-01-01

    We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region.

  13. Unexpected Melt at Summit, Greenland: Its Potential Legacy

    NASA Astrophysics Data System (ADS)

    Albert, M. R.

    2012-12-01

    Summit, Greenland is a high altitude cold site where snow on the ice sheet rarely melts; it was the site where the GISP2 ice core was drilled almost two decades ago. In July 2012, unusual meteorological events caused the surface snow at Summit to experience a very rare true melt event. The melt period was short-lived, and subfreezing temperatures soon turned the melt into an ice layer. Modern satellite-born sensing technologies provided the first opportunity to witness and confirm that indeed the melt was very widespread over most of the surface of the Greenland Ice Sheet. Many tens of meters beneath the firn surface at Summit is the next significantly thick ice layer, dating to 1889; this layer also has been identified at a number of other sites in Greenland. The 2012 melt at Summit provided an unusual opportunity to investigate the way in which the melt alters the properties of the snow at this site. Measurements of the nature of the melt at Summit in 2012 and its impact on stratigraphy, density, permeability, and grain size are presented. Insights from the observations we made in July 2012 and comparisons with characteristics of the 1889 ice layer from Summit are employed in a description of the potential impacts of refrozen melt layers on polar snow and firn processes in the dry snow zones of ice sheets. The potential legacy that the 2012 ice layer may imprint on future ice core records is discussed.

  14. First Characterization of Avian Influenza Viruses from Greenland 2014.

    PubMed

    Hartby, Christina Marie; Krog, Jesper Schak; Merkel, Flemming; Holm, Elisabeth; Larsen, Lars Erik; Hjulsager, Charlotte Kristiane

    2016-05-01

    In late February 2014, unusually high numbers of wild thick-billed murres (Uria lomvia) were found dead on the coast of South Greenland. To investigate the cause of death, 45 birds were submitted for laboratory examination in Denmark. Avian influenza viruses (AIVs) with subtypes H11N2 and low pathogenic H5N1 were detected in some of the birds. Characterization of the viruses by full genome sequencing revealed that all the gene segments belonged to the North American lineage of AIVs. The seemingly sparse and mixed subtype occurrence of low pathogenic AIVs in these birds, in addition to the emaciated appearance of the birds, suggests that the murre die-off was due to malnutrition as a result of sparse food availability or inclement weather. Here we present the first characterization of AIVs isolated in Greenland, and our results support the idea that wild birds in Greenland may be involved in the movement of AIV between North America and Europe.

  15. Radar attenuation and temperature within the Greenland Ice Sheet

    USGS Publications Warehouse

    MacGregor, Joseph A; Li, Jilu; Paden, John D; Catania, Ginny A; Clow, Gary D.; Fahnestock, Mark A; Gogineni, Prasad S.; Grimm, Robert E.; Morlighem, Mathieu; Nandi, Soumyaroop; Seroussi, Helene; Stillman, David E

    2015-01-01

    The flow of ice is temperature-dependent, but direct measurements of englacial temperature are sparse. The dielectric attenuation of radio waves through ice is also temperature-dependent, and radar sounding of ice sheets is sensitive to this attenuation. Here we estimate depth-averaged radar-attenuation rates within the Greenland Ice Sheet from airborne radar-sounding data and its associated radiostratigraphy. Using existing empirical relationships between temperature, chemistry, and radar attenuation, we then infer the depth-averaged englacial temperature. The dated radiostratigraphy permits a correction for the confounding effect of spatially varying ice chemistry. Where radar transects intersect boreholes, radar-inferred temperature is consistently higher than that measured directly. We attribute this discrepancy to the poorly recognized frequency dependence of the radar-attenuation rate and correct for this effect empirically, resulting in a robust relationship between radar-inferred and borehole-measured depth-averaged temperature. Radar-inferred englacial temperature is often lower than modern surface temperature and that of a steady state ice-sheet model, particularly in southern Greenland. This pattern suggests that past changes in surface boundary conditions (temperature and accumulation rate) affect the ice sheet's present temperature structure over a much larger area than previously recognized. This radar-inferred temperature structure provides a new constraint for thermomechanical models of the Greenland Ice Sheet.

  16. Factors Controlling Methane in Arctic Lakes of Southwest Greenland.

    PubMed

    Northington, Robert M; Saros, Jasmine E

    2016-01-01

    We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region. PMID:27454863

  17. Factors Controlling Methane in Arctic Lakes of Southwest Greenland

    PubMed Central

    2016-01-01

    We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region. PMID:27454863

  18. Tributyltin accumulation and effects in marine molluscs from West Greenland.

    PubMed

    Strand, Jakob; Asmund, Gert

    2003-01-01

    The levels of the antifouling agent tributyltin (TBT) and its breakdown products in bivalves were investigated in 1999-2000 at six areas along the west coast of Greenland with focus on locations inside and outside harbours. In addition female gastropods were examined for the development of TBT-induced masculine characteristics in form of imposex or intersex. The highest TBT concentration, 254 ng x g(-1) ww, was found in the bivalve Mytilus edulis sampled inside Nuuk harbour, but significant TBT concentrations were also present in bivalves from the other harbour areas. Only low levels of TBT were detected in bivalves sampled outside the harbours and in several of the samples the TBT level was below the detection limit. The examination of neogastropods like Buccinum revealed that imposex development occurred in all the harbours. In contrast, imposex was not found in any neogastropods sampled outside the harbour areas. However, the value of marine neogastropods as indicators of TBT contamination in West Greenland seems limited, because of large species diversity and the difficulties in sampling enough specimens at least with the current sampling strategy. No effects, which could be related to TBT contamination, were found in the most abundant tidal gastropod in West Greenland, Littorina saxatilis.

  19. Continental ice in Greenland during the Eocene and Oligocene.

    PubMed

    Eldrett, James S; Harding, Ian C; Wilson, Paul A; Butler, Emily; Roberts, Andrew P

    2007-03-01

    The Eocene and Oligocene epochs (approximately 55 to 23 million years ago) comprise a critical phase in Earth history. An array of geological records supported by climate modelling indicates a profound shift in global climate during this interval, from a state that was largely free of polar ice caps to one in which ice sheets on Antarctica approached their modern size. However, the early glaciation history of the Northern Hemisphere is a subject of controversy. Here we report stratigraphically extensive ice-rafted debris, including macroscopic dropstones, in late Eocene to early Oligocene sediments from the Norwegian-Greenland Sea that were deposited between about 38 and 30 million years ago. Our data indicate sediment rafting by glacial ice, rather than sea ice, and point to East Greenland as the likely source. Records of this type from one site alone cannot be used to determine the extent of ice involved. However, our data suggest the existence of (at least) isolated glaciers on Greenland about 20 million years earlier than previously documented, at a time when temperatures and atmospheric carbon dioxide concentrations were substantially higher.

  20. Unusual radar echoes from the Greenland ice sheet

    NASA Technical Reports Server (NTRS)

    Rignot, E. J.; Vanzyl, J. J.; Ostro, S. J.; Jezek, K. C.

    1993-01-01

    In June 1991, the NASA/Jet Propulsion Laboratory airborne synthetic-aperture radar (AIRSAR) instrument collected the first calibrated data set of multifrequency, polarimetric, radar observations of the Greenland ice sheet. At the time of the AIRSAR overflight, ground teams recorded the snow and firn (old snow) stratigraphy, grain size, density, and temperature at ice camps in three of the four snow zones identified by glaciologists to characterize four different degrees of summer melting of the Greenland ice sheet. The four snow zones are: (1) the dry-snow zone, at high elevation, where melting rarely occurs; (2) the percolation zone, where summer melting generates water that percolates down through the cold, porous, dry snow and then refreezes in place to form massive layers and pipes of solid ice; (3) the soaked-snow zone where melting saturates the snow with liquid water and forms standing lakes; and (4) the ablation zone, at the lowest elevations, where melting is vigorous enough to remove the seasonal snow cover and ablate the glacier ice. There is interest in mapping the spatial extent and temporal variability of these different snow zones repeatedly by using remote sensing techniques. The objectives of the 1991 experiment were to study changes in radar scattering properties across the different melting zones of the Greenland ice sheet, and relate the radar properties of the ice sheet to the snow and firn physical properties via relevant scattering mechanisms. Here, we present an analysis of the unusual radar echoes measured from the percolation zone.

  1. Arctic coastal zone mapping: Evolution of sedimentary coasts in Greenland

    NASA Astrophysics Data System (ADS)

    Bendixen, M.; Kroon, A.

    2015-12-01

    Climate change threatens many of the coastal areas all over the world. In the Arctic, the warming happens at a rate which is three times faster than the global average increasing the pressure on the coast. Arctic coasts differ from coasts in lower latitude in terms of the natural conditions prevailing, i.e. sea-ice, permafrost, and thermal erosion. These factors are likely to change with an increasing temperature, and thereby the erodibility of the shores and the erosivity of the coastal processes are changing. The majority of studies on arctic coasts focus on tundra coasts. Here, there is a general increase of coastal erosion rates over the last decades. However, the arctic coastal areas of Greenland differ; they are often close to hard rock protrusions and are characterized by large differences in geomorphology, erodibility of sediments, and erosivity by coastal processes. Sedimentary coasts in Greenland are only sporadically investigated, and it is thus difficult to predict the impact of climate changes in these areas. With this work we focus on sedimentary coasts in Greenland and present shoreline analysis of two sedimentary coastal sites. We show how the position of the shoreline has changed since the 1930'ies and we address the responsible factors controlling this evolution. The hotspots of coastal change are all located near delta mouths and the detected changes are coupled to dominating process occurring here.

  2. Unmanned Aircraft System (UAS) Assessment of Melt Lakes in Greenland

    NASA Astrophysics Data System (ADS)

    Adler, J.; Steffen, K.

    2007-12-01

    The objective of this August 2007 week-long test campaign was to assess the viability of supraglacial lake depths with high-resolution hyperspectral measurements. The knowledge of melt lake depth is essential in determining the volume of water which forms on top of glacial surfaces during the annual melt season. The assessment of melt water volume is a crucial input parameter for modeling the Greenland ice sheet dynamics. UAS operations were flown out of western Greenland. Preliminary results from five hyperspectral data cubes are presented, indicating that supraglacial water depths can be determined from low altitude, high-resolution hyperspectral imaging. The pixel resolution of the hyperspectral sensor is 0.2 meters at an altitude of 300 meters above the ice surface; this provides accuracy that is two orders of magnitude better than imagery obtained by the MODIS sensor or other similar satellite-based methods. Further, a UAS-based hyperspectral approach enables the measurement of supraglacial lake depths under most cloud cover conditions. The capabilities of three UAS types (Manta, Silver Fox, and electric Silver Fox) flight tested in Greenland are discussed. Also, we present future field planning (2008 and 2009) to measure supraglacial lake depths with hyperspectral imagery in conjunction with a green laser altimeter.

  3. Greenland supraglacial rivers and the extreme 2012 melt season

    NASA Astrophysics Data System (ADS)

    Smith, L. C.; Rennermalm, A. K.; Legleiter, C. J.; Behar, A. E.; Chu, V. W.; Forster, R. R.; Gleason, C. J.; Moustafa, S.; Overstreet, B. T.; Pitcher, L. H.; Tedesco, M.; Yang, K.

    2012-12-01

    July 2012 was an extreme melt period for the Greenland ice sheet, affecting up to ~97% of its surface and producing severe proglacial flooding and destruction of an important bridge at Kangerlussuaq. This presentation summarizes collaborative, multi-institutional research to study the production, storages and fluxes of Greenland ice sheet meltwater in supraglacial streams, rivers and lakes that form on the ice surface and emerge as proglacial braided rivers downstream at its edge. The 2012 field season focused on supraglacial river hydraulics, with unprecedented measurements of flow velocity, bathymetric depth, surface slope, hydraulic roughness coefficient, and water-column optical attenuation and spectral characteristics, acquired using telemetered river drifters, Acoustic Doppler Current Profiler (ADCP), an unmanned drone boat, and traditional field surveys. Field sites span ~520 to 1600 m elevation and range from the ice terminus up to ~85 km into the ice sheet interior. These new datasets are especially valuable for scale-up and calibration of remotely sensed observations owing to targeted acquisitions of WorldView-2 and ASTER visible/NIR satellite imagery made contemporaneously with the field measurements. Preliminary analysis indicates that Greenland supraglacial rivers represent major, high-flux pathways for meltwater transport, with flow velocities and hydraulic characteristics quite extraordinary as compared with terrestrial rivers.

  4. Evidence of Meltwater Retention within the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Rennermalm, A. K.; Smith, L. C.; Chu, V. W.; Box, J. E.; Forster, R. R.; van den Broeke, M. R.

    2012-12-01

    Greenland ice sheet water release, and the magnitude of sub- and englacial storage, firn densification, internal refreezing and other hydrologic processes that delay or reduce true water export to the global ocean remain poorly understood. This problem is compounded by scant hydrometerological measurements. Here, ice sheet surface meltwater runoff and proglacial river discharge determined between 2008 and 2010 for three sites near Kangerlussuaq, western Greenland were used to establish the water budget for a small ice sheet watershed. The water budget could not be closed in the three years, even when uncertainty ranges were considered. Instead, between 12% and 53% of ice sheet surface runoff is retained within the catchment each melt year (time between onset of ice sheet runoff in two consecutive years) most likely in en- and subglacial storages. Evidence suggests that while some holdover summer meltwater may escape during the cold-season, this water volume is too small to close the budget. Thus, this study indicates that the Greenland ice sheet cryo-hydrologic system may remain active year round, and that meltwater may be retained in the pro glacial area, internally, or in firn layers for prolonged time periods before release to the ocean.

  5. Observed runoff, jokulhlaups and suspended sediment load from the Greenland ice at Kangerlussuaq, West Greenland, 2007 and 2008

    SciTech Connect

    Mernild, Sebastian Haugard; Hasholt, Bent

    2009-01-01

    This study fills the gap in hydrologic measurements of runoff exiting a part of the Greenland Ice Sheet (GrIS), the Kangerlussuaq drainage area, West Greenland. The observations are of value for obtaining knowledge about the terrestrial freshwater and sediment output from part of the GrIS and the strip of land between the GrIS and the ocean, in the context of varying ice sheet surface melt and influx entering the ocean. High-resolution stage, discharge and suspended sediment load show a decrease in runoff of {approx} 25% and in sediment load of {approx} 40% from 2007 to 2008 in response to a decrease in the summer accumulated number of positive degree days. During the 2007 and 2008 runoff season, joekulhlaups are observed at Kangerlussuaq, drained from an ice-dammed lake at the margin of the GrIS.

  6. 77 FR 50712 - Information Collection: Southern Alaska Sharing Network and Subsistence Study; Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ... Bureau of Ocean Energy Management Information Collection: Southern Alaska Sharing Network and Subsistence... in Alaska, ``Southern Alaska Sharing Network and Subsistence Study.'' DATES: Submit written comments.... Title: Southern Alaska Sharing Network and Subsistence Study. Abstract: The Bureau of Ocean...

  7. Geology of the Alaska-Juneau lode system, Alaska

    USGS Publications Warehouse

    Twenhofel, William Stephens

    1952-01-01

    The Alaska-Juneau lode system for many years was one of the worlds leading gold-producing areas. Total production from the years 1893 to 1946 has amounted to about 94 million dollars, with principal values in contained gold but with some silver and lead values. The principal mine is the Alaska-Juneau mine, from which the lode system takes its name. The lode system is a part of a larger gold-bearing belt, generally referred to as the Juneau gold belt, along the western border of the Coast Range batholith. The rocks of the Alaska-Juneau lode system consist of a monoclinal sequence of steeply northeasterly dipping volcanic, state, and schist rocks, all of which have been metamorphosed by dynamic and thermal processes attendant with the intrusion of the Coast Range batholith. The rocks form a series of belts that trend northwest parallel to the Coast Range. In addition to the Coast Range batholith lying a mile to the east of the lode system, there are numerous smaller intrusives, all of which are sill-like in form and are thus conformable to the regional structure. The bedded rocks are Mesozoic in age; the Coast Range batholith is Upper Jurassic and Lower Cretaceous in age. Some of the smaller intrusives pre-date the batholith, others post-date it. All of the rocks are cut by steeply dipping faults. The Alaska-Juneau lode system is confined exclusively to the footwall portion of the Perseverance slate band. The slate band is composed of black slate and black phyllite with lesser amounts of thin-bedded quartzite. Intrusive into the slate band are many sill-like bodies of rocks generally referred to as meta-gabbro. The gold deposits of the lode system are found both within the slate rocks and the meta-gabbro rocks, and particularly in those places where meta-gabbro bodies interfinger with slate. Thus the ore bodies are found in and near the terminations of meta-gabbro bodies. The ore bodies are quartz stringer-lodes composed of a great number of quartz veins from 6

  8. Organotropism of persistent organic pollutants and heavy metals in the Greenland shark Somniosus microcephalus in NE Greenland.

    PubMed

    Corsolini, Simonetta; Ancora, Stefania; Bianchi, Nicola; Mariotti, Giacomo; Leonzio, Claudio; Christiansen, Jørgen S

    2014-10-15

    The Greenland shark Somniosus microcephalus is an opportunistic feeder, a top predator, and a very long-lived species. The brain, liver, red and white muscle, gonads, fat, skin, pancreas, and spleen of Greenland sharks from NE Greenland fjords were analysed for PCBs, PCDDs/DFs, PBDEs; DDT isomers; HCH isomers; dieldrin; endrin; HCB; Cd, Hg, Pb, and Se. PCBs (2.01-103 ng/g wet wt) and PBDEs (7.9-3050 pg/g wet wt) were detected in most of the samples. PCDDs/DFs showed high values when detected. DDTs, HCB and HCHs were only detected in some tissues. The ΣTEQ was 5.76 pg/g in muscle. Cadmium mainly accumulated in the pancreas and liver (19.6 and 10.7 mg/kg dry wt, respectively); mercury in red muscle (4.10-6.91 mg/kg dry wt); selenium in the pancreas (3.57 mg/kg dry wt) and spleen (1.95 mg/kg dry wt); lead in the skin (0.358 mg/kgd ry wt). The selenium-mercury ratio in the liver was also evaluated.

  9. Late-Holocene Fluctuations of the Greenland Ice Sheet: Insights from a south Greenland threshold lake

    NASA Astrophysics Data System (ADS)

    Sinclair, G.; Carlson, A. E.; Reilly, B.

    2015-12-01

    Several centennial-scale climate fluctuations during the late-Holocene make it an ideal test case for examining the effects of climate change on sea level at societally-relevant timescales. Across much of the Arctic, glaciers and ice sheets reached their maximum late-Holocene extent during the Little Ice Age (LIA, 1400-1900 C.E.), approximately coincident with the global temperature minima observed during this time. However, ongoing work suggests the south Greenland Ice Sheet (sGrIS) may have behaved differently during the late-Holocene, with several outlet glaciers retreating, rather than advancing, during the LIA, possibly due to regional warming in the region different from the Arctic trend. The Qassimiut lobe, a low-lying piedmont-like extension of the sGrIS, may be especially sensitive to late-Holocene climate changes. Geomorphic evidence outboard of Naujaat Sermia, an outlet glacier draining the Qassimiut lobe, suggests three distinct periods of land exposure. We hypothesize these occurred during the last deglacial period, after an advance from near or behind the present margin during the Neoglacial, and during warming following the Little Ice Age in the last 1-2 centuries. Here, we present data from threshold lake cores immediately outboard of the presumed Neoglacial moraine. A sharp contact divides glacial sands and silts from organic gyttja, indicating glacial retreat from the moraine and subsequent meltwater diversion. The contact is accompanied by several geochemical changes, including increased Fe/Ti ratios, increased Br, and decreased Si and K, indicating a switch from more clastic to organic sedimentation. Radiocarbon ages from eight macrofossils immediately above this contact are calibrated to 1350-1950 C.E., suggesting the ice sheet may have retreated from its late-Holocene maximum during the Little Ice Age, but the wide range in ages suggests reworking of organic material may be significant in this region.

  10. Greenland temperature response to climate forcing during the last deglaciation

    NASA Astrophysics Data System (ADS)

    Buizert, C.; Gkinis, V.; Severinghaus, J. P.; He, F.; Lecavalier, B.; Kindler, P.; Leuenberger, M.; Carlson, A. E.; Vinther, B.; White, J. W.; Liu, Z.; Otto-Bliesner, B. L.; Brook, E.

    2013-12-01

    Much of the regional and global climate variability during the last glacial termination (19-11 ka BP) can be explained as the superposition of two distinct modes (1, 2); a spatially uniform increase in global temperature correlated with greenhouse gas forcing, and a redistribution of heat associated with variability in the Atlantic meridional overturning circulation (AMOC) strength. The latter mode is expressed most clearly in the abrupt climate shifts recorded in the precipitation isotopic composition (δ18O) of Greenland ice cores, which are now widely used as a template for abrupt change in the northern hemisphere. Greenland δ18O is influenced by many factors, including source temperature, moisture transport and origin, and precipitation seasonality, complicating reconstruction of past temperatures. Here we use three non-δ18O temperature reconstructions from three ice cores and a general circulation model (GCM) to elucidate the (often abrupt) Greenland surface temperature response to external (insolation) and internal (CO2, AMOC, ice topography) climate forcings during the last termination. Our reconstructions are based on δ15N (NEEM, GISP2) and water isotope diffusion (NGRIP), both of which depend on physical processes in the firn column. The GCM and our reconstructions show excellent agreement on several key features. First, we find that the Younger Dryas (YD) period was 4-6oC warmer than the Oldest Dryas (OD) period in response to increased summer insolation and CO2 forcing. By contrast, δ18O-based reconstrucions from Greenland summit suggest the YD to be the colder of the two periods. Our finding is consistent with non-ice core NH proxy reconstructions, as well as with East Greenland deglacial moraine sequences that suggest only a modest glacial re-advance during the YD. Second, the YD-OD temperature difference shows a polar amplification signal, with warming being greatest at the northernmost NEEM site. By isolating different forcings in the GCM, we

  11. Has dynamic thinning switched off in south-east Greenland?

    NASA Astrophysics Data System (ADS)

    Murray, T.; Scharrer, K.; James, T. D.; Dye, S. R.; Hanna, E.; Booth, A. D.; Selmes, N.; Luckman, A.; Hughes, A. L. C.; Huybrechts, P.

    2009-04-01

    Following a relatively stable period during the 1990's, dramatic changes have been reported for many tidewater outlets in the south-eastern part of the Greenland Ice Sheet (GrIS). Results from measurements using the GRACE (Gravity Recovery and Climate Experiment) mission clearly identified the south-eastern part of the GrIS as having the highest rates of mass loss (1, 2). Two of the major outlet glaciers in this area, Helheim and Kangerdlugssuaq, accelerated by about 100 percent and 40 percent, respectively, and their calving fronts retreated by several km (3). Retreat and acceleration occurred in two phases during summer 2003 and 2005 at Helheim, and in a single period between late 2004 and early 2005 at Kangerdlugssuaq. Further south widespread glacier acceleration between 1996 and 2005 affected most of the outlet glaciers (4). In all Greenland's mass loss was calculated to have doubled in the period (4). Increased discharge due to thinning in the marginal areas, coupled to rapid changes in ice dynamics and synchronous retreat of their calving front positions, led to speculations that the GrIS had crossed a "tipping point" induced by global warming. However, subsequent studies showed that during summer 2006 Helheim and Kangerlugssuaq had simultaneously slowed down and their thinning had stopped. Because variability in the ice sheet's mass loss results mostly from the SE Greenland sector, further understanding of the nature, distribution, and controls of dynamic change in this region is essential. In order to examine the extent of the dynamic changes and to identify their cause we used satellite data to measure glacier surface elevation and calving front positions of 24 outlets of 14 major tidewater terminating glaciers, as well as speeds of 9 outlets in SE Greenland. We concentrate on the region where the GRACE data show highest rates of mass change and our data cover the period during and after the cessation of fast flow and thinning at Helheim and

  12. Has dynamic thinning switched off in south-east Greenland?

    NASA Astrophysics Data System (ADS)

    Murray, T.; Scharrer, K.; James, T.; Luckman, A.; Selmes, N.; Cook, S.; Hughes, A.; Cordero Llana, L.; Booth, A.; McGovern, J.; Rutt, I.

    2008-12-01

    Following a relatively stable period during the 1990s, dramatic changes have been reported for many tidewater outlets in SE Greenland. Some of the most important results come from measurements using the GRACE (Gravity Recovery and Climate Experiment) mission (1, 2). These data clearly identified the SE of the Greenland Ice Sheet (GrIS) as having the highest rates of mass loss. Two of the major outlet glaciers in this area, Helheim and Kangerdlugssuaq accelerated by about 100% and 40%, respectively, and their calving fronts retreated by several km (3, 4). Retreat and acceleration occurred in two phases during summer 2003 and 2005 at Helheim, and in a single period between late 2004 and early 2005 at Kangerdlugssuaq. Further south, widespread glacier acceleration between 1996 and 2005 affected most of the outlet glaciers, and Greenland's mass loss doubled in the period (5). Increased discharge due to thinning in the marginal areas, coupled to rapid changes in ice dynamics and synchronous retreat of calving front positions, led to speculations that the GrIS had crossed a "tipping point" induced by global warming. However, subsequent studies in summer 2006 showed that Helheim and Kangerdlugssuaq had simultaneously slowed down again and thinning stopped (6). In summer 2007, we collected lidar data over Helheim and Kangerdlugssuaq flown by the NERC Airborne Research and Survey Facility. Data collected were single swaths over mountain areas, as well as centerline profiles. In cooperation with NASA Goddard Space Flight Center, we conducted a similar but extended campaign in 2008, collecting lidar and radar data for the 16 largest outlet glaciers in SE Greenland, targeting the full extent of the major GRACE anomaly. We used lidar swaths from bedrock as ground-control for extracting DEMs from ASTER satellite images covering the period with major changes in 2004 to 2006, and compared them to lidar and SPOT 5 DEMs to produce the most recent volume change and velocity estimates

  13. Columbia Glacier, Alaska, 1986-2011

    NASA Video Gallery

    The Columbia Glacier in Alaska is one of many vanishing around the world. Glacier retreat is one of the most direct and understandable effects of climate change. The consequences of the decline in ...

  14. 77 FR 35998 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... Nunapiglluraq Corporation (Native Village of Hamilton). The decision approves the surface estate in the lands... is conveyed to Nunapiglluraq Corporation. The lands are in the vicinity of Hamilton, Alaska, and...

  15. Alaska Simulator - A Journey to Planning

    NASA Astrophysics Data System (ADS)

    Weber, Barbara; Pinggera, Jakob; Zugal, Stefan; Wild, Werner

    The Alaska Simulator is an interactive software tool developed at the University of Innsbruck which allows people to test, analyze and improve their own planning behavior. In addition, the Alaska Simulator can be used for studying research questions in the context of software project management and other related fields. Thereby, the Alaska Simulator uses a journey as a metaphor for planning a software project. In the context of software project management the simulator can be used to compare traditional rather plan-driven project management methods with more agile approaches. Instead of pre-planning everything in advance agile approaches spread planning activities throughout the project and provide mechanisms for effectively dealing with uncertainty. The biggest challenge thereby is to find the right balance between pre-planning activities and keeping options open. The Alaska Simulator allows to explore how much planning is needed under different circumstances.

  16. 76 FR 72212 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-22

    ... conveyance pursuant to the Alaska Native Claims Settlement Act (43 U.S.C. 1601, et seq). The subsurface... published four times in The Delta Discovery. DATES: Any party claiming a property interest in the...

  17. 78 FR 64002 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ... for conveyance pursuant to the Alaska Native Claims Settlement Act (43 U.S.C. 1601, et seq.). The... decision will also be published once a week for four ] consecutive weeks in the Delta Discovery. DATES:...

  18. 77 FR 20046 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... described below pursuant to the Alaska Native Claims Settlement Act (ANCSA) (43 U.S.C. 1601, et seq.). The lands being approved for conveyance are lands originally selected under ANCSA in the withdrawal area...

  19. Advancing Efforts to Energize Native Alaska (Brochure)

    SciTech Connect

    Not Available

    2013-04-01

    This brochure describes key programs and initiatives of the DOE Office of Indian Energy Policy and Programs to advance energy efficiency, renewable energy, and energy infrastructure projects in Alaska Native villages.

  20. Cross Cultural Scientific Communication in Alaska

    NASA Astrophysics Data System (ADS)

    Bertram, K. B.

    2006-12-01

    An example of cross-cultural education is provided by the Aurora Alive curriculum. Aurora Alive communicates science to Alaska Native students through cross-cultural educational products used in Alaska schools for more than a decade, including (1) a CDROM that provides digital graphics, bilingual (English and Athabascan language) narration-over-text and interactive elements that help students visualize scientific concepts, and (2) Teacher's Manuals containing more than 150 hands-on activities aligned to national science standards, and to Alaska Standards for Culturally Responsive Schools. Created by Native Elders and teachers working together with University Alaska Fairbanks Geophysical Institute scientists, Aurora Alive blends Native "ways of knowing" with current "western" research to teach the physics and math of the aurora.