WorldWideScience

Sample records for rongelap atoll recommendations

  1. Radionuclides in sediments and seawater at Rongelap Atoll

    Energy Technology Data Exchange (ETDEWEB)

    Noshkin, V.E.; Robison, W.L.; Eagle, R.J.; Brunk, J.L.

    1998-03-01

    The present concentrations and distributions of long-lived, man-made radionuclides in Rongelap Atoll lagoon surface sediments, based on samples collected and analyzed in this report. The radionuclides were associated with debris generated with the 1954 Bravo thermonuclear test at Bikini Atoll. Presently, only {sup 90}Sr and the transuranic radionuclides are found associated with the surface sediments in any quantity. Other radionuclides, including {sup 60}Co and {sup 137} Cs, are virtually absent and have either decayed or migrated from the deposits to the overlying seawater. Present inventories of {sup 241}Am and {sup 249+240}Pu in the surface layer at Rongelap are estimated to be 3% of the respective inventories in surface sediments from Bikini Atoll. There is a continuous slow release of the transuranics from the sediments back to the water column. The inventories will only slowly change with time unless the chemical-physical processes that now regulate this release to the water column are changed or altered.

  2. Transuranics in bone of deceased former residents of Rongelap Atoll, Marshall Islands

    International Nuclear Information System (INIS)

    Franke, B.; Schupfner, R.; Schuettelkopf, H.; Spennemann, D.H.R.

    1995-01-01

    Rongelap Atoll received intensive fallout from the 1 March 1954 Bravo thermonuclear test 105 miles upwind at Bikini. Fearful of their continued exposure to radiation, the residences of Rongelap Atoll went into voluntary exile in 1985. Transuranic soil concentrations on Rongelap Island are about 2-3 orders of magnitude greater than the average for the Northern hemisphere; the three dominating transuranic are 239,240 Pu and 241 Am. Only conflicting information has been available about the extent of transuranic uptake by the Rongelap community. As part of the Rongelap Resettlement Project, the community endorsed the exhumation of bones of deceased former atoll residents to provide an independent estimate of plutonium intake. This approach has the advantage of reducing the uncertainties associated with pathway modeling and the interpretation of urine data. Six graves (4 adults, 2 children) were selected for exhumation. Femora and tibiae were selected as well as humeri from the children's graves. The rest of the remains were left undisturbed. The results of the analysis of 239,240 Pu and 241 Am are presented. Assuming that the data can be considered as representative for the Rongelap population as a whole, the contamination with transuranics on Rongelap Atoll appears to result in radiation exposures in the order of 1% of the compliance limit of 100 mrem (1 mSv) effective dose equivalent per year. (author)

  3. Transuranics in bone of deceased former residents of Rongelap Atoll, Marshall Islands

    Energy Technology Data Exchange (ETDEWEB)

    Franke, B. [Institute for Energy and Environmental Research, Takoma Park, MD (United States)]|[Institut fuer Energie- und Umweltforschung e.V., Heidelberg (Germany); Schupfner, R.; Schuettelkopf, H. [Regensburg Univ. (Germany). Lab. for Environmental Radioactivity; Spennemann, D.H.R. [Charles Sturt Univ., Albury (Australia). School of Environmental and Information Sciences

    1995-11-01

    Rongelap Atoll received intensive fallout from the 1 March 1954 Bravo thermonuclear test 105 miles upwind at Bikini. Fearful of their continued exposure to radiation, the residences of Rongelap Atoll went into voluntary exile in 1985. Transuranic soil concentrations on Rongelap Island are about 2-3 orders of magnitude greater than the average for the Northern hemisphere; the three dominating transuranic are {sup 239,240}Pu and {sup 241}Am. Only conflicting information has been available about the extent of transuranic uptake by the Rongelap community. As part of the Rongelap Resettlement Project, the community endorsed the exhumation of bones of deceased former atoll residents to provide an independent estimate of plutonium intake. This approach has the advantage of reducing the uncertainties associated with pathway modeling and the interpretation of urine data. Six graves (4 adults, 2 children) were selected for exhumation. Femora and tibiae were selected as well as humeri from the children`s graves. The rest of the remains were left undisturbed. The results of the analysis of {sup 239,240}Pu and {sup 241}Am are presented. Assuming that the data can be considered as representative for the Rongelap population as a whole, the contamination with transuranics on Rongelap Atoll appears to result in radiation exposures in the order of 1% of the compliance limit of 100 mrem (1 mSv) effective dose equivalent per year. (author).

  4. Transuranics in bone of deceased former residents of Rongelap Atoll, Marshall Islands.

    Science.gov (United States)

    Franke, B; Schupfner, R; Schüttelkopf, H; Spennemann, D H

    1995-11-01

    Rongelap Atoll received intensive fallout from the 1 March 1954 Bravo thermonuclear test 105 miles upwind at Bikini. Fearful of their continued exposure to radiation, the residents of Rongelap Atoll went into voluntary exile in 1985. Transuranic soil concentrations on Rongelap Island are about 2-3 orders of magnitude greater than the average for the Northern hemisphere; the three dominating transuranics are 239,240Pu and 241Am. Only conflicting information has been available about the extent of transuranic uptake by the Rongelap community. As part of the Rongelap Resettlement Project, the community endorsed the exhumation of bones of deceased former atoll residents to provide an independent estimate of plutonium intake. This approach has the advantage of reducing the uncertainties associated with pathway modeling and the interpretation of urine data. Six graves (4 adults, 2 children) were selected for exhumation. Femora and tibiae were selected as well as humeri from the children's graves. The rest of the remains was left undisturbed. The results of the analysis of 239,240Pu and 241Am are presented. Assuming that the data can be considered as representative for the Rongelap population as a whole, the contamination with transuranics on Rongelap Atoll appears to result in radiation exposures in the order of 1% of the compliance limit of 100 mrem (1 mSv) effective dose equivalent per year.

  5. External radiation survey and dose predictions for Rongelap, Utirik, Rongerik, Ailuk, and Wotje Atolls

    International Nuclear Information System (INIS)

    Greenhouse, N.A.; Miltenberger, R.P.

    1977-01-01

    External radiation measurements were made at several atolls in the northern Marshall Islands, which are known or suspected to have been the recipients of tropospheric fallout during the Pacific Testing Programs. Sufficient data were available to ascertain realistic dose predictions for the inhabitants of Rongelap and Utirik Atolls where the 30 year integral doses from external sources exclusive of background radiation were 0.65 and 0.06 rem respectively. These estimates are based on realistic life-style models based on observations of each atoll community. Ailuk and Wotje Atolls were found to be represenatives of regional background radiation levels

  6. A comparison of independently conducted dose assessments to determine compliance and resettlement options for the people of Rongelap Atoll

    International Nuclear Information System (INIS)

    Simon, S.L.; Robison, W.L.; Thorne, M.C.

    1997-01-01

    Rongelap Island was the home of Marshallese people numbering less than 120 in 1954; 67 were on the island and severely exposed to radioactive fallout from an atomic weapons test in March of that year. Those resident on Rongelap were evacuated 50 h after the test, returned 3 y later, then voluntarily left their home island in 1985 due to their ongoing fear of radiation exposure from residual radioactive contamination. Following international negotiations in 1991, a Memorandum of Understanding (NIOU) was signed in early 1992 between the Republic of the Marshall Islands Government, the Rongelap Atoll Local Government, the U.S. Department of Energy, and the U.S. Department of the Interior. In this MOU it was agreed that the Republic of the Marshall Islands, with the aid of the U.S. Department of Energy, would carry out independent dose assessments for the purpose of assisting and advising the Rongelap community on radiological issues related to a safe resettlement of Rongelap. In 1994, four independent assessments were reported, including one from each of the following entities: Marshall Islands Nationwide Radiological Study; Lawrence Livermore National Laboratory; an independent advisor from the United Kingdom (MCT); and a committee of the National Research Council. All four assessments concluded that possibly more than 25% of the adult population could exceed the 1 mSv y -1 dose level based on strict utilization of a local food diet. The purpose of this report is to summarize the methodology, assumptions, and findings from each of four assessments; to summarize the recommendations related to mitigation and resettlement options; to discuss unique programmatic aspects of the study; and to consider the implications of the findings to the future of the Rongelap people. 63 refs., 5 figs., 3 tabs

  7. Radiological conditions at Naen, Yugui, Lomiulal, Kabelle and Mellu Islands in the northern half of Rongelap Atoll

    International Nuclear Information System (INIS)

    Robison, W.L.; Conrado, C.L.

    1996-03-01

    The data presented in the following tables is the total available for each northern island; they include both the data from the 1978 Northern Marshall Island Radiological Survey (NMIRS) and trips to Rongelap Atoll from 1986 through 1989. In one table we present the number of vegetation samples collected in the 1978 NMIRS and from 1986 through 1989. Again the majority of the 137 Cs data is from the 1986-1989 trips. We have not made additional analyses of 239+240 Pu, 241 Am and 90 Sr because the concentrations are very low and these radionuclides contribute less than 5% of an already very small dose. In another table we show the number of soil samples collected at each island in 1978 and the number collected since 1986. Most of the data are from 1986 through 1989. The major exception is 90 Sr where all of the data are from the 1978 NMIRS. We have done some additional Pu analyses of surface soils (0-5 cm depth) in the northern islands. A significant amount of new data for 137 Cs and 241 Am have been generated from the samples collected from 1986 through 1989. The data are presented in the form of summary tables, graphics, detailed appendices and aerial photographs of the islands with the sample locations marked. The identified sample locations from the 1978 NMIRS will be added later

  8. Collection and processing of plant, animal and soil samples from Bikini, Enewetak and Rongelap Atolls

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, M.L.

    1995-09-01

    The United States used the Marshall Islands for its nuclear weapons program testing site from 1946 to 1958. The BRAVO test was detonated at Bikini Atoll on March 1, 1954. Due to shifting wind conditions at the time of the nuclear detonation, many of the surrounding Atolls became contaminated with fallout (radionuclides carried by the wind currents). Lawrence Livermore National Laboratory`s (LLNL) Marshall Islands Project has been responsible for the collecting, processing, and analyzing of food crops, vegetation, soil, water, animals, and marine species to characterize the radionuclides in the environment, and to estimate dose at atolls that may have been contaminated. Tropical agriculture experiments reducing the uptake of {sup 137}Cs have been conducted on Bikini Atoll. The Marshall Islands field team and laboratory processing team play an important role in the overall scheme of the Marshall Islands Dose Assessment and Radioecology Project. This report gives a general description of the Marshall Islands field sampling and laboratory processing procedures currently used by our staff.

  9. Collection and processing of plant, animal and soil samples from Bikini, Enewetak and Rongelap Atolls

    International Nuclear Information System (INIS)

    Stuart, M.L.

    1995-09-01

    The United States used the Marshall Islands for its nuclear weapons program testing site from 1946 to 1958. The BRAVO test was detonated at Bikini Atoll on March 1, 1954. Due to shifting wind conditions at the time of the nuclear detonation, many of the surrounding Atolls became contaminated with fallout (radionuclides carried by the wind currents). Lawrence Livermore National Laboratory's (LLNL) Marshall Islands Project has been responsible for the collecting, processing, and analyzing of food crops, vegetation, soil, water, animals, and marine species to characterize the radionuclides in the environment, and to estimate dose at atolls that may have been contaminated. Tropical agriculture experiments reducing the uptake of 137 Cs have been conducted on Bikini Atoll. The Marshall Islands field team and laboratory processing team play an important role in the overall scheme of the Marshall Islands Dose Assessment and Radioecology Project. This report gives a general description of the Marshall Islands field sampling and laboratory processing procedures currently used by our staff

  10. An updated dose assessment for Rongelap Island

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W.L.; Conrado, C.L.; Bogen, K.T.

    1994-07-01

    We have updated the radiological dose assessment for Rongelap Island at Rongelap Atoll using data generated from field trips to the atoll during 1986 through 1993. The data base used for this dose assessment is ten fold greater than that available for the 1982 assessment. Details of each data base are presented along with details about the methods used to calculate the dose from each exposure pathway. The doses are calculated for a resettlement date of January 1, 1995. The maximum annual effective dose is 0.26 mSv y{sup {minus}1} (26 mrem y{sup {minus}1}). The estimated 30-, 50-, and 70-y integral effective doses are 0.0059 Sv (0.59 rem), 0.0082 Sv (0.82 rem), and 0.0097 Sv (0.97 rem), respectively. More than 95% of these estimated doses are due to 137-Cesium ({sup 137}Cs). About 1.5% of the estimated dose is contributed by 90-Strontium ({sup 90}Sr), and about the same amount each by 239+240-Plutonium ({sup 239+240}PU), and 241-Americium ({sup 241}Am).

  11. The department of energy's environmental monitoring support for Rongelap resettlement in the Marshall Island: a partnership for the future

    International Nuclear Information System (INIS)

    Bell, T.R.

    2002-01-01

    The Department of Energy (DOE) initiated a dedicated program in 1974 to determine residual levels of contamination remaining in the Northern Marshall Islands from the 66 Pacific atmospheric nuclear weapons tests. The United States atmospheric nuclear weapons test code-named 'Castle BRAVO', conducted at the Bikini atoll in 1954, inadvertently deposited radioactive fallout on 253 residents of the Rongelap and Utrik atolls. The Rongelap people were evacuated 3 days after Castle Bravo, but not before they received significant fallout doses. Although the Rongelap people resettled on Rongelap Island from June 1957 until May 1985, the Rongelap community self-exiled themselves at that time for fear of what they believed to be rising levels of 137 Cs in their local food supplies. Since that time, the U.S. government has worked with the Rongelap people in a partnership to address environmental concerns and provide environmental monitoring, dose assessment data and information and mitigation strategy alternatives. DOE has been an instrumental partner in agreements, town meetings, interactions at the level of the local atoll government councils as well as the government of the Republic of the Marshall Islands have been needed to do this successfully. (author)

  12. Radiological assessments for resettlement of Rongelap in the Republic of the Marshall Islands

    International Nuclear Information System (INIS)

    1994-01-01

    The Committee on Radiological Safety in the Marshall Islands was established by the National Research Council in response to a request from the US Department of Energy (DOE) to assist the department in evaluating radiological conditions on certain atolls in the Republic of the Marshall Islands, especially Rongelap Atoll. The need stems from the provisions of a memorandum of understanding (MOU) established between the Republic of the Marshall Islands and the US in 1992. That agreement sets out criteria and stipulations pertaining to the resettlement of Rongelap Atoll. The issue of resettlement itself originated in the desire for the people of the Marshall Islands to return to the atolls from which they were evacuated as a consequence of nuclear-weapons testing by the US during the 1940s and 1950s. The National Research Council was asked to review the scientific studies undertaken by the US Department of Energy to determine if reliable and modern scientific methodology was being used to assess the potential hazard, if any, to persons who might return to live on Rongelap Atoll. A crucial provision of the MOU is that resettlement will occur only if no person returning to Rongelap and substituting on a native-foods-only diet will receive a calculated annual whole-body radiation dose equivalent of more than 100 mrem above background. The MOU also presents an action level of 17 pCi/g for the concentration of transuranic contamination, i.e., plutonium and americium, in soils below which mitigation will be considered unnecessary

  13. Protracted exposure to fallout: the Rongelap and Utirik experience

    Energy Technology Data Exchange (ETDEWEB)

    Lessard, E.T.; Miltenberger, R.P.; Cohn, S.H.; Musolino, S.V.; Conard, R.A.

    1984-03-01

    From June 1946 to August 1958, the U.S. Department of Defense and the U.S. Atomic Energy Commission (AEC) conducted nuclear weapons tests in the Northern Marshall Islands. On 1 March 1954, BRAVO, an above-ground test in the Castle series, produced high levels of radioactive material, some of which subsequently fell on Rongelap and Utirik Atolls due to an unexpected wind shift. On 3 March 1954, the inhabitants of these atolls were moved out of the affected area. They later returned to Utirik in June 1954 and to Rongelap in June 1957. Comprehensive environmental and personnel radiological monitoring programs were initiated in the mid 1950s by Brookhaven National Laboratory to ensure that body burdens of the exposed Marshallese subjects remained within AEC guidelines. Their body-burden histories and calculated activity ingestion rate patterns post-return are presented along with estimates of internal committed effective dose equivalents. External exposure data are also included. In addition, relationships between body burden or urine-activity concentration and declining continuous intake were developed.

  14. Protracted exposure to fallout: the Rongelap and Utirik experience.

    Science.gov (United States)

    Lessard, E T; Miltenberger, R P; Cohn, S H; Musolino, S V; Conard, R A

    1984-03-01

    From June 1946 to August 1958, the U.S. Department of Defense and the U.S. Atomic Energy Commission (AEC) conducted nuclear weapons tests in the Northern Marshall Islands. On 1 March 1954, BRAVO, an above-ground test in the Castle series, produced high levels of radioactive material, some of which subsequently fell on Rongelap and Utirik Atolls due to an unexpected wind shift. On 3 March 1954, the inhabitants of these atolls were moved out of the affected area. They later returned to Utirik in June 1954 and to Rongelap in June 1957. Comprehensive environmental and personnel radiological monitoring programs were initiated in the mid 1950s by Brookhaven National Laboratory to ensure that body burdens of the exposed Marshallese subjects remained within AEC guidelines. Their body-burden histories and calculated activity ingestion rate patterns post-return are presented along with estimates of internal committed effective dose equivalents. External exposure data are also included. In addition, relationships between body burden or urine-activity concentration and declining continuous intake were developed. The implications of these studies are: (1) the dietary intake of 137Cs was a major component contributing to the committed effective dose equivalent for the years after the initial contamination of the atolls; (2) for persons whose diet included fish, 65Zn was a major component of committed effective dose equivalent during the first years post-return; (3) a decline in the daily activity ingestion rate greater than that resulting from radioactive decay of the source was estimated for 137Cs, 65Zn, 90Sr and 60Co; (4) the relative impact of each nuclide on the estimate of committed effective dose equivalent was dependent upon the time interval between initial contamination and rehabilitation; and (5) the internal committed effective dose equivalent exceeded the external dose equivalent by a factor of 1.1 at Utirik and 1.5 at Rongelap during the rehabitation period. Few

  15. Assessment of plutonium exposures in Rongelap and Utirik populations by fission track analysis of urine

    International Nuclear Information System (INIS)

    Sun, L.C.; Moorthy, A.R.; Kaplan, E.; Baum, J.W.; Meinhold, C.B.

    1994-01-01

    A nuclear device, code-named Bravo, detonated at Bikini Atoll at 6:45 a.m. on 1 March 1954, unexpectedly released a large amount of radioactivity. Over 40 years after this incident, the study of its impact on the radiological health and environmental safety of the residents of Rongelap and Utirik Atolls continues. In 1987, researchers at Brookhaven National Laboratory established a fission track analysis (FTA) method for low-level 239 Pu urinalysis. Two years later, a new shipboard protocol was developed for collecting 24-h radiologically clean urine samples. The purpose of this paper is to update information on the FTA method for measuring low-levels of plutonium, and to summarize results on the distribution of 239 Pu in the populations of Rongelap and Utirik between 1981--1991. Plutonium detection levels (99% confidence level) in these samples were 2--3 μBq, which is equivalent to 0.2--0.3 mSv effective dose equivalent (EDE) to age 70 for Marshallese. The latest 1991 FTA data indicate average EDE of 0.62 mSv and 1.6 mSv for the people of Rongelap and Utirik, respectively, which both are the highest values since 1988

  16. Assessment of plutonium exposures in Rongelap and Utirik populations by fission track analysis of urine

    International Nuclear Information System (INIS)

    Sun, L.C.; Moorthy, A.R.; Kaplan, E.; Baum, J.W.; Meinhold, C.B.

    1995-01-01

    A nuclear device, code-named Bravo, detonated at Bikini Atoll at 6.45 a.m. on 1 March 1954, unexpectedly released a large amount of radioactivity. Over 40 years after this incident, the study of its impact on the radiological health and environmental safety of the residents of Rongelap and Utirik Atolls continues. In 1987, researchers at Brookhaven National Laboratory established a fission track analysis (FTA) method for low-level 239 Pu urinalysis. Two years later, a new shipboard protocol was developed for collecting 24-h radiologically clean urine samples. The purpose of this paper is to update information on the FTA method for measuring low-levels of plutonium, and to summarize results on the distribution of 239 Pu in the populations of Rongelap and Utirik between 1981-1991. Plutonium detection levels (99% confidence level) in these samples were 2-3 μBq, which is equivalent to 0.2-0.3 mSv effective dose equivalent (EDE) to age 70 for Marshallese. The latest 1991 FTA data indicate average EDE of 0.62 mSv and 1.6 mSv for the people of Rongelap and Utirik, respectively, which both are the highest values since 1988. (author)

  17. Aerial radiological and photographic survey of eleven atolls and two islands within the Northern Marshall Islands. Dates of surveys, July-November 1978

    International Nuclear Information System (INIS)

    1981-06-01

    An aerial radiological survey was conducted over eleven atolls and two islands within the northern Marshall Islands between September and November 1978. This survey was part of a comprehensive radiological survey, which included extensive terrestrial and marine sampling, to determine possible residual contamination which might remain as a result of the United States nuclear testing program conducted at Bikini Enewetak Atolls between 1946 and 1958. A similar survey was conducted at Enewetak Atoll in 1972. The present survey covered those atolls known to have received direct fallout from the Bravo event, conducted in March 1954 at Bikini Atoll. These included Bikini, Rongelap, Rongerik, Ailinginae, Bikar, Taka, and Utirik Atolls. In addition, several atolls and islands which might have been at the fringes of the Bravo fallout were also surveyed, including Likiep and Ailuk Atolls, Jemo and Mejit Islands, and Wotho Atoll. Ujelang Atoll, which lies approximately 200 km southwest of Enewetak, was also surveyed. Island-averaged terrestrial exposure rates in the range of 30 to 50 μR/h were observed over parts of Bikini Atoll, including Bikini Island, and over the northern part of Rongelap Atoll. Levels over southern Rongelap and over Rongerik Atoll ranged from 4 to 7 μR/h. Levels were somewhat lower at Ailinginae Atoll (approximately 2 μR/h) and at Utirik Atoll (approximately 0.7 μR/h). The variations observed were consistent with what might be expected from the fallout pattern of the Bravo event. Levels at Ailuk, Likiep, Wotho and Ujelang Atolls and at Mejit and Jemo Islands were consistent with 137 Cs activity, due to worldwide fallout, observed within the United States and at other locations in the central Pacific. These four atolls and the two islands, therefore, do not appear to have recieved any significant direct contamination from the Bravo event or the other tests conducted at Bikini and Enewetak Atolls

  18. Radiological survey of plants, animals, and soil at five atolls in the Marshall Islands; September--October 1976

    International Nuclear Information System (INIS)

    Nelson, V.A.

    1979-01-01

    The Division of Operational Safety's portion of the Pacific Radioecology Program began in 1974 and it is a continuing program to determine the kinds and amounts of radionuclides distributed in the foods, plants, animals, and soils of the Central Pacific, especially the Marshall Islands. As part of this program, Wotje, Ailuk, Utirik, Rongelap, and Bikini tolls were visited in 1976 and samples collected. Results of the radiometric analyses of the samples are presented. Results of these analyses indicate that 90 Sr and 137 Cs are predominant in the terrestrial environment and, in addition, 241 Am and 239 240 Pu are also important in the soil from Rongelap and Bikini Atols. Naturally occurring 40 K is the predominant radionuclide in marine organisms, while 60 Co is significant in the tridacnid clams. Amounts of radioactivity vary with distance from the Bikini test site and in relation to the fallout pattern from the March 1954 Bravo test. Thus, samples from Bikini Atol had the greatest amounts of radioactivity while the northern islands of Rongelap had slightly lower amounts. The southern islands of Rongelap Atoll and Utirik Atoll had intermediate amounts of radioactivity while Ailuk and Wotje atolls had the least radioactivity of the atolls visited

  19. Radiological survey of plants, animals, and soil at Christmas Island and seven atolls in the Marshall Islands. Progress report for 1974--1975

    International Nuclear Information System (INIS)

    Nelson, V.A.

    1977-01-01

    The Division of Operational Safety or DOS (now Safety Standards and Compliance) portion of the Laboratory of Radiation Ecology (LRE) Pacific Radiocology Program (formerly Johnston Atoll Program) began on 1 July 1974 and is continuing. The purpose of this program is to determine the kinds and amounts of radionuclides distributed in the foods, plants, animals, and soil of the Central Pacific, especially the Marshall Islands. Five field trips were conducted for this program between April 1974 and August 1975, and about 600 samples were collected. Results of the analyses indicate that 90 Sr and 137 Cs are dominant in the terrestrial environment and, in addition, 241 Am and /sup 239,240/Pu are also important in the soil from Bikini and Rongelap atolls. Cobalt-60 and 55 Fe are predominant in the marine environment together with naturally occurring 40 K. Amounts of radioactivity vary between atolls and between islands within an atoll in relation to the distance from the nuclear weapons test sites. Bikini atoll has the highest amounts of radioactivity, but the northern islands of Rongelap Atoll have only slightly lower amounts. Rongerik and Ailinginae atolls and the southern islands of Rongelap Atoll have similar amounts of radioactivity which are lower than Bikini by factors of 5 to 10 or more. Values at Utirik Atoll are lower still, but are higher than amounts at Wotho and Kwajalein atolls. Christmas Island in the Line Islands has the least amount of radioactivity of the areas surveyed for this report

  20. Radiation doses for Marshall Islands Atolls Affected by U.S. Nuclear Testing:All Exposure Pathways, Remedial Measures, and Environmental Loss of 137Cs

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W L; Hamilton, T F

    2009-04-20

    The United States conducted 24 nuclear tests at Bikini Atoll with a total yield of 76.8 Megatons (MT). The Castle series produced about 60% of this total and included the Bravo test that was the primary source of contamination of Bikini Island and Rongelap and Utrok Atolls. One of three aerial drops missed the atoll and the second test of the Crossroads series, the Baker test, was an underwater detonation. Of the rest, 17 were on barges on water and 3 were on platforms on an island; they produced most of the contamination of islands at the atoll. There were 42 tests conducted at Enewetak Atoll with a total yield of 31.7 MT (Simon and Robison, 1997; UNSCEAR, 2000). Of these tests, 18 were on a barge over wateror reef, 7 were surface shots, 2 aerial drops, 2 under water detonations, and 13 tower shots on either land or reef. All produced some contamination of various atoll islands. Rongelap Atoll received radioactive fallout as a result of the Bravo test on March 1, 1954 that was part of the Castle series of tests. This deposition was the result of the Bravo test producing a yield of 15 MT, about a factor of three to four greater than the predicted yield that resulted in vaporization of more coral reef and island than expected and in the debris-cloud reaching a much higher altitude than anticipated. High-altitude winds were to the east at the time of detonation and carried the debris-cloud toward Rongelap Atoll. Utrok Atoll also received fallout from the Bravo test but at much lower air and ground-level concentrations than at Rongelap atoll. Other atolls received Bravo fallout at levels below that of Utrok [other common spellings of this island and atoll (Simon, et al., 2009)]. To avoid confusion in reading other literature, this atoll and island are spelled in a variety of ways (Utrik, Utirik, Uterik or Utrok). Dose assessments for Bikini Island at Bikini Atoll (Robison et al., 1997), Enjebi Island at Enewetak Atoll (Robison et al., 1987), Rongelap Island at

  1. Radiation doses for Marshall Islands Atolls affected by U.S. nuclear testing: all exposure pathways, remedial measures, and environmental loss of (137)Cs.

    Science.gov (United States)

    Robison, William L; Hamilton, Terry F

    2010-01-01

    Radiation doses calculated for people resettling Bikini Island at Bikini Atoll, Enjebi Island at Enewetak Atoll, Rongelap Island at Rongelap Atoll, and Utrōk Island at Utrōk Atoll are presented. Residence is assumed to begin in 2010. In previous dose assessments it was shown that (137)Cs accounts for about 98% of the total dose for returning residents. About 85 to 90% (depending on the atoll) is via consumption of locally grown foods containing (137)Cs, and about 10 to 15% is due to external exposure from (137)Cs in the soil. These assessments were made using only the radiological half-life of (137)Cs (30.1 y). We have shown since that there is an environmental loss of (137)Cs from soil to groundwater that results in a more rapid loss of (137)Cs from the atoll ecosystem. The mean effective half-life of (137)Cs at the atolls is 8.5 y. Moreover, treatment of coconut trees with potassium (K) reduces (137)Cs concentration in drinking coconut meat at Bikini Atoll to about 5% of pretreatment concentrations. The magnitude of reduction is dependent on the concentration of (137)Cs in soil, and thereby in food crops, and is less for Enjebi and Rongelap Islands than for Bikini Island. Treatment of food crops and fruit trees with K and removal of the top 15 cm of soil around houses and community buildings prior to construction to reduce external exposure where people spend most of their time has been presented to the communities as a "Combined Option" remediation strategy. Doses presented here are calculated using the Combined Option, effective half-life of (137)Cs at the atolls, and a diet of both imported and local foods. The average natural background dose in the Marshall Islands, plus the anthropogenic nuclear test-related dose at Bikini, Enjebi, and Rongelap Islands, is less for each of the islands than the average background dose in the U.S. and Europe.

  2. Biosecurity Plan for Palmyra Atoll

    Science.gov (United States)

    Hathaway, Stacie A.; Fisher, Robert N.

    2010-01-01

    extent and impacts of these and other non-native and (or) invasive species are not fully understood, they are clearly a threat to the native species and overall ecosystem integrity of Palmyra Atoll. In fact, non-native invasive species have been considered the most important threat to ecosystems in Hawai`i and the second most important threat to biodiversity world-wide. Palmyra Atoll is somewhat protected because of its remote location, but there are still potential pathways for the introduction of non-native and possibly invasive species. With the continued influx of aircraft and ocean vessels and their contents to and around Palmyra Atoll, we anticipate many more concerns related to the import and spread of non-native invasive species in the future. In terms of ecosystem security, prevention is the most effective and efficient tool for managing invasive species. There are various potential pathways for introduction and spread of non-native species within Palmyra Atoll's terrestrial and marine ecosystems. Identification of these pathways provides a first step in preventing introductions. We also recommend establishing, enhancing, and enforcing quarantine protocols to prevent future non-native species invasions. Other critical steps to minimize the impacts and spread of invasive species include early detection through inventory and monitoring, as well as containment, control, and management of non-native species already established at Palmyra Atoll. These efforts in combination with research and education will serve to inform management decisions related to ecosystem integrity. Along with reinstating ecosystem security, this Biosecurity Plan aims to evaluate new risk factors related to non-native and potentially invasive species. To that end, an adaptive management process of audit and review is highly recommended to ensure the implementation and efficacy of the management practices outlined above. In addition, it will be important to identify high r

  3. Thyroid disease among the Rongelap and Utirik population - an update

    International Nuclear Information System (INIS)

    Howard, J.E.; Vaswani, A.; Heotis, P.

    1997-01-01

    In 1954, 253 Marshallese were accidentally exposed to fallout radiation from the hydrogen bomb, BRAVO. The Marshall Islands Medical Program (MIMP) was established by the Department of Energy in 1955 to monitor and treat radiation-related disease pursuant to this accident. Medical teams from Brookhaven National laboratory, a federal institution, regularly visit the Marshall Islands to give medical care to the exposed population. The most significant complication of the exposure has been found to be thyroid disease due to the ingestion of radioactive iodides from the fallout. In 1963 the first thyroid nodules were found in Rongelap subjects and in 1969 in Utirik. Non-neoplastic adenomatous nodules were associated with higher doses of radiation and neoplastic nodules developed in individuals receiving lower doses of radiation. Women were more susceptible to the development of palpable thyroid nodules than men. In 1994 the MIMP initiated examination of the thyroid by ultrasound to supplement the clinical examination. One hundred and sixty-four patients were evaluated. No significant differences were found in the incidence of thyroid nodules or the mean nodule count between the three groups of Rongelap and Utirik exposed and a comparison patient population. There was no significant difference in the incidence of thyroid nodules in males vs. females. Five exposed patients were referred for surgical excision of a nodule detected only by ultrasound. These ultrasound findings are unexpected in that females are known to have a higher incidence of thyroid disease than males and we expected that the incidence of ultrasound nodules would be higher in the exposed population. 36 refs., 2 figs., 8 tabs

  4. Bikini Atoll coral biodiversity resilience five decades after nuclear testing

    International Nuclear Information System (INIS)

    Richards, Zoe T.; Beger, Maria; Pinca, Silvia; Wallace, Carden C.

    2008-01-01

    Five decades after a series of nuclear tests began, we provide evidence that 70% of the Bikini Atoll zooxanthellate coral assemblage is resilient to large-scale anthropogenic disturbance. Species composition in 2002 was assessed and compared to that seen prior to nuclear testing. A total of 183 scleractinian coral species was recorded, compared to 126 species recorded in the previous study (excluding synonomies, 148 including synonomies). We found that 42 coral species may be locally extinct at Bikini. Fourteen of these losses may be pseudo-losses due to inconsistent taxonomy between the two studies or insufficient sampling in the second study, however 28 species appear to represent genuine losses. Of these losses, 16 species are obligate lagoonal specialists and 12 have wider habitat compatibility. Twelve species are recorded from Bikini for the first time. We suggest the highly diverse Rongelap Atoll to the east of Bikini may have contributed larval propagules to facilitate the partial resilience of coral biodiversity in the absence of additional anthropogenic threats

  5. Bikini Atoll coral biodiversity resilience five decades after nuclear testing

    Energy Technology Data Exchange (ETDEWEB)

    Richards, Zoe T. [Museum of Tropical Queensland, Flinders St, Townsville, QLD 4810 (Australia) and Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811 (Australia) and School of Marine and Tropical Biology, James Cook University, Townsville QLD 4811 (Australia); NRAS - Marshall Islands: Natural Resource Assessment Surveys (Australia)], E-mail: zoe.richards@jcu.edu.au; Beger, Maria [Ecology Centre and Commonwealth Research Facility for Applied Environmental Decision Analysis, University of Queensland, St Lucia, QLD 4072 (Australia); NRAS - Marshall Islands: Natural Resource Assessment Surveys (Australia); Pinca, Silvia [College of the Marshall Islands, Majuro, Marshall Islands, NRAS - Marshall Islands: Natural Resource Assessment Surveys (Australia); Wallace, Carden C. [Museum of Tropical Queensland, Flinders St, Townsville, QLD 4810 (Australia)

    2008-03-15

    Five decades after a series of nuclear tests began, we provide evidence that 70% of the Bikini Atoll zooxanthellate coral assemblage is resilient to large-scale anthropogenic disturbance. Species composition in 2002 was assessed and compared to that seen prior to nuclear testing. A total of 183 scleractinian coral species was recorded, compared to 126 species recorded in the previous study (excluding synonomies, 148 including synonomies). We found that 42 coral species may be locally extinct at Bikini. Fourteen of these losses may be pseudo-losses due to inconsistent taxonomy between the two studies or insufficient sampling in the second study, however 28 species appear to represent genuine losses. Of these losses, 16 species are obligate lagoonal specialists and 12 have wider habitat compatibility. Twelve species are recorded from Bikini for the first time. We suggest the highly diverse Rongelap Atoll to the east of Bikini may have contributed larval propagules to facilitate the partial resilience of coral biodiversity in the absence of additional anthropogenic threats.

  6. 137Cs Inter-Plant Concentration Ratios Provide a Predictive Tool for Coral Atolls with Distinct Benefits Over Transfer Factors

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W L; Hamilton, T F; Bogen, K; Corado, C L; Kehl, S R

    2007-07-17

    Inter-plant concentration ratios (IPCR), [Bq g{sup -1} {sup 137}Cs in coral atoll tree food-crops/Bq g{sup -1} {sup 137}Cs in leaves of native plant species whose roots share a common soil volume], can replace transfer factors (TF) to predict {sup 137}Cs concentration in tree food-crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact tree roots naturally integrate 137Cs over large volumes of soil. Root absorption of {sup 137}Cs replaces large-scale, expensive soil sampling schemes to reduce variability in {sup 137}Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log normally distributed (LND) with geometric standard deviation (GSD) = 1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSD's of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD = 1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF variability, relative sampling error of an IPCR field sample mean is up 6- to 10-fold lower than that of a TF sample mean if sample sizes are small (10 to 20). Other IPCR advantages are that plant leaf samples are collected and processed in far less time with much less effort and cost than soil samples.

  7. 137Cs inter-plant concentration ratios provide a predictive tool for coral atolls with distinct benefits over transfer factors

    International Nuclear Information System (INIS)

    Robison, William L.; Hamilton, Terry F.; Bogen, Kenneth T.; Conrado, Cynthia L.; Kehl, Steven R.

    2008-01-01

    Inter-plant concentration ratios (IPCR) [Bq g -1137 Cs in coral atoll tree food crops/Bq g -1137 Cs in leaves of native plant species whose roots share a common soil volume] can replace transfer factors (TF) to predict 137 Cs concentration in tree food crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact that tree roots naturally integrate 137 Cs over large volumes of soil. Root absorption of 137 Cs replaces large-scale, expensive soil sampling schemes to reduce variability in 137 Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log-normally distributed (LND) with geometric standard deviation (GSD) = 1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSDs of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD = 1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF variability, relative sampling error of an IPCR field sample mean is up 6- to 10-fold lower than that of a TF sample mean if sample sizes are small (10-20). Other IPCR advantages are that plant leaf samples are collected and processed in far less time with much less effort and cost than soil samples

  8. Meteorites, atolls and whisky

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1967-06-15

    Improvements in the methods of measuring radioactive traces of elements in substances which can be hundreds of millions of years old have enabled many secrets of the remote past to be revealed. The techniques developed by nuclear scientists can also be applied to more recent times. In a symposium held in Monaco during March the discussions of radioactive dating and methods of low level counting brought references to meteorites, rocks, archaeology, coral atolls, ancient ceramics, and even whisky

  9. Bikini Atoll groundwater development

    International Nuclear Information System (INIS)

    Peterson, F.L.

    1985-01-01

    Nuclear weapons testing during the 1950's has left the soil and ground water on Bikini Atoll contaminated with cesium-137, and to a lesser extent, strontium-90. Plans currently are underway for the clean-up and resettlement of the atoll by removal of approximately the upper 30 cm of soil. Any large-scale resettlement program must include provisions for water supply. This will be achieved principally by catchment and storage of rain water, however, since rainfall in Bikini is highly seasonal and droughts occur frequently, ground water development must also be considered. The quantity of potable ground water that can be developed is limited by its salinity and radiological quality. The few ground water samples available from Bikini, which have been collected from only about the top meter of the groundwater body, indicate that small bodies of potable ground water exist on Bikini and Eneu, the two principal living islands, but that cesium and strontium in the Bikioni ground water exceed drinking water standards. In order to make a reasonable estimate of the ground water development potential for the atoll, some 40 test boreholes will be drilled during July/August 1985, and a program of water quality monitoring initiated. This paper will describe preliminary results of the drilling and monitoring work

  10. Thyroid absorbed dose for people at Rongelap, Utirik, and Sifo on March 1, 1954

    International Nuclear Information System (INIS)

    Lessard, E.T.; Miltenberger, R.P.; Conrad, R.A.; Musoline, S.V.; Naidu, J.R.; Moorthy, A.; Schopfer, C.J.

    1985-03-01

    A study was undertaken to reexamine thyroid absorbed dose estimates for people accidentally exposed to fallout at Rongelap, Sifo, and Utirik Islands from the Pacific weapon test known as Operation Castle BRAVO. The study included: (1) reevaluation of radiochemical analysis, to relate results from pooled urine to intake, retention, and excretion functions; (2) analysis of neutron-irradiation studies of archival soil samples, to estimate areal activities of the iodine isotopes; (3) analysis of source term, weather data, and meteorological functions used in predicting atmospheric diffusion and fallout deposition, to estimate airborne concentrations of the iodine isotopes; and (4) reevaluation of radioactive fallout, which contaminated a Japanese fishing vessel in the vicinity of Rongelap Island on March 1, 1954, to determine fallout components. The conclusions of the acute exposure study were that the population mean thyroid absorbed doses were 21 gray (2100 rad) at Rongelap, 6.7 gray (670 rad) at Sifo, and 2.8 gray (280 rad) at Utirik. The overall thyroid cancer risk we estimated was in agreement with results published on the Japanese exposed at Nagasaki and Hiroshima. We now postulate that the major route for intake of fallout was by direct ingestion of food prepared and consumed outdoors. 66 refs., 13 figs., 25 tabs

  11. Thyroid absorbed dose for people at Rongelap, Utirik, and Sifo on March 1, 1954

    Energy Technology Data Exchange (ETDEWEB)

    Lessard, E.T.; Miltenberger, R.P.; Conrad, R.A.; Musoline, S.V.; Naidu, J.R.; Moorthy, A.; Schopfer, C.J.

    1985-03-01

    A study was undertaken to reexamine thyroid absorbed dose estimates for people accidentally exposed to fallout at Rongelap, Sifo, and Utirik Islands from the Pacific weapon test known as Operation Castle BRAVO. The study included: (1) reevaluation of radiochemical analysis, to relate results from pooled urine to intake, retention, and excretion functions; (2) analysis of neutron-irradiation studies of archival soil samples, to estimate areal activities of the iodine isotopes; (3) analysis of source term, weather data, and meteorological functions used in predicting atmospheric diffusion and fallout deposition, to estimate airborne concentrations of the iodine isotopes; and (4) reevaluation of radioactive fallout, which contaminated a Japanese fishing vessel in the vicinity of Rongelap Island on March 1, 1954, to determine fallout components. The conclusions of the acute exposure study were that the population mean thyroid absorbed doses were 21 gray (2100 rad) at Rongelap, 6.7 gray (670 rad) at Sifo, and 2.8 gray (280 rad) at Utirik. The overall thyroid cancer risk we estimated was in agreement with results published on the Japanese exposed at Nagasaki and Hiroshima. We now postulate that the major route for intake of fallout was by direct ingestion of food prepared and consumed outdoors. 66 refs., 13 figs., 25 tabs.

  12. Dose assessment at Bikini Atoll

    International Nuclear Information System (INIS)

    Robison, W.L.; Phillips, W.A.; Colsher, C.S.

    1977-01-01

    Bikini Atoll is one of two sites in the northern Marshall Islands that was used by the United States as testing grounds for the nuclear weapons program from 1946 to 1958. In 1969 a general cleanup began at Bikini Atoll. Subsistence crops, coconut and Pandanus fruit, were planted on Bikini and Eneu Islands, and housing was constructed on Bikini Island. A second phase of housing was planned for the interior of Bikini Island. Preliminary data indicated that external gamma doses in the interior of the island might be higher than in other parts of the island. Therefore, to select a second site for housing on the island with minimum external exposure, a survey of Bikini Atoll was conducted in June 1975. External gamma measurements were made on Bikini and Eneu Islands, and soil and vegetations samples collected to evaluate the potential doses via terrestrial food chains and inhalation. Estimates of potential dose via the marine food chain were based upon data collected on previous trips to the atoll. The terrestrial pathway contributes the greater percentage, external gamma exposure contributes the next highest, and inhalation and marine pathways contribute minor fractions of the total whole body and bone marrow doses. The radionuclides contributing the major fraction of the dose are 90 Sr and 137 Cs. All living patterns involving Bikini Island exceed federal guidelines for 30-yr population doses. The Eneu Island living pattern leads to doses that are slightly less than federal guidelines. All patterns evaluated for Bikini Atoll lead to higher doses than those on the southern islands at Enewetak Atoll

  13. Technical Basis Document: A Statistical Basis for Interpreting Urinary Excretion of Plutonium Based on Accelerator Mass Spectrometry (AMS) for Selected Atoll Populations in the Marshall Islands

    International Nuclear Information System (INIS)

    Bogen, K; Hamilton, T F; Brown, T A; Martinelli, R E; Marchetti, A A; Kehl, S R; Langston, R G

    2007-01-01

    We have developed refined statistical and modeling techniques to assess low-level uptake and urinary excretion of plutonium from different population group in the northern Marshall Islands. Urinary excretion rates of plutonium from the resident population on Enewetak Atoll and from resettlement workers living on Rongelap Atoll range from 239 Pu. However, our statistical analyses show that urinary excretion of plutonium-239 ( 239 Pu) from both cohort groups is significantly positively associated with volunteer age, especially for the resident population living on Enewetak Atoll. Urinary excretion of 239 Pu from the Enewetak cohort was also found to be positively associated with estimates of cumulative exposure to worldwide fallout. Consequently, the age-related trends in urinary excretion of plutonium from Marshallese populations can be described by either a long-term component from residual systemic burdens acquired from previous exposures to worldwide fallout or a prompt (and eventual long-term) component acquired from low-level systemic intakes of plutonium associated with resettlement of the northern Marshall Islands, or some combination of both

  14. Review at Bikini Atoll. Assessing radiological conditions at Bikini Atoll and the prospects for resettlement

    International Nuclear Information System (INIS)

    Stegnar, P.

    1998-01-01

    Some testing during the development of the atomic bomb was done in countries that do not have the infrastructure and expertise for evaluating any associated radiation risks. In such cases, outside expertise is needed to obtain independent advice about the radiological situation caused by residual radioactive material from nuclear testing. The IAEA has been requested by the governments of a number of its Member States to provide assistance in this context. Among the former nuclear test sites which the IAEA has reviewed is the Bikini Atoll of the Marshall Islands. Based on its review, the IAEA Advisory Group determined that no further corroboration of the measurements and assessments of the radiological conditions at Bikini Atoll is necessary. The data that have been collected are of sufficient quality to allow an appropriate evaluation to be performed. The limited IAEA monitoring of the area provided a good quality assurance verification of the previously collected data. It was recommended that Bikini Island should not be permanently resettled under the present radiological conditions. This recommendation was based on the assumption that persons resettling on the island would consume a diet of entirely locally produced food. The radiological data support that if a diet of this type were permitted, it could lead to an annual effective dose of about 15 mSv. This level was judged to require intervention of some type for radiation protection purposes

  15. Marine radioactivity assessment of Mururoa and Fangataufa atolls

    International Nuclear Information System (INIS)

    Povinec, P.P.; Dovlete, C.; Gastaud, J.; Ikeuchi, Y.; Wee Kwong, L.L.; Mulsow, S.; Pettersson, H.; Woodhead, D.; Blowers, P.; Bonfield, R.; Smedley, P.; Taylor, B.; Cooper, M.; Chen, Q.; Dahlgaard, H.; Fox, V.; Morgenstern, U.; Taylor, C.; Froehlich, K.; Groening, M.; Hamilton, T.; Kanisch, G.; Krueger, A.; Matthews, M.; Tinker, R.

    1999-01-01

    The International Atomic Energy Agency (IAEA) carried out an international project 'The Study of the Radiological Situation at the Atolls of Mururoa and Fangataufa' with the aim of assessing the present and future radiological situation at the atolls and making recommendations for either monitoring or remedial actions if they are deemed necessary. The paper concentrates on marine radioactivity aspects and gives an estimation of present radionuclide concentrations in water, sediment and biota of the Mururoa and Fangataufa lagoons and the surrounding ocean. The dominant radionuclide in both lagoons is Pu in sediments (the total inventory is approximately 30 TBq). A decline in radionuclide concentrations has been observed in recent years in lagoon water, with the exception of 3H and 90Sr, for which a contribution from underground sources is to be expected. Radionuclide concentrations in biota from the lagoons and the surrounding ocean are low and consistent with previous measurements. The observed radionuclide concentrations in both lagoons imply that no radiological risk exists for hypothetical inhabitants of Mururoa and Fangataufa Atolls

  16. CRED REA Algal Assessments, Johnston Atoll 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines as part of Rapid Ecological Assessments conducted at 17 sites at Johnston Atoll in...

  17. CRED REA Algal Assessments Wake Atoll, 2007

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines as part of Rapid Ecological Assessments conducted at 12 sites at Wake Atoll in April...

  18. An Ecological Assessment of Johnston Atoll

    Science.gov (United States)

    2012-01-01

    limits Short-nose Wrasse, Macropharyngodon geoffroy Global Climate Event causes Coral Bleaching Research by Anne L. Cohen, P. S. Lobel, and Gabrielle L...L. Tomasky. An unusual event of Coral bleaching on Johnston Atoll, Central Pacific Ocean. Biological Bulletin 193:276-279. On 10 September 1996...extensive coral bleaching was noted on Johnston Atoll. Between September 1996 and March 1997 the nature and extent of the bleaching , as well as the

  19. Resettlement of Bikini Atoll U.S. Nuclear Test Site

    International Nuclear Information System (INIS)

    Robinson, W.L.; Conrado, C.L.; Stuart, M.L.; Stoker, A.C.; Hamilton, T.F.

    1999-01-01

    The US conducted a nuclear testing program at Bikini and Enewetak Atolls in the Marshall Islands from 1946 through 1958. Several atolls, including Bikini, were contaminated as a result of the nuclear detonations. Since 1974 the authors have conducted an extensive research and monitoring program to determine the radiological conditions at the atolls, identify the critical radionuclides and pathways, estimate the radiological dose to current or resettling populations, and develop remedial measures to reduce the dose to atoll populations. This paper describes exposure pathways and radionuclides; composition of atoll soils; radionuclide transport and dose estimates; remedial measures; and reduction in dose from a combined option

  20. Plutonium radionuclides in the ground waters at Enewetak Atoll

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Wong, K.M.; Marsh, K.; Eagle, R.; Holladay, G.; Buddemeier, R.W.

    1975-01-01

    In 1974 a groundwater program was initiated at Eniwetok Atoll to study systematically the hydrology and the ground water geochemistry on selected islands of the Atoll. The program provides chemical and radiochemical data for assessment of water quality on those islands designated for rehabilitation. These and other data are used to interpret the mechanisms by which radionuclides are cycled in the soil-groundwater system. Because of the international concern over the long-term buildup, availability, and transport of plutonium in the environment, this program emphasizes analysis of the element. The results of the study show that on all islands sampled, small quantities of plutonium radionuclides have migrated through the soil columns and are redistributed throughout the groundwater reservoirs. The observed maximum surface concentrations are less than 0.02 percent of the maximal recommended concentration for drinking water. Concentrations of 137 Cs are found to correlate with water freshness, but those of 239 , 240 Pu show no such relationship. The mechanisms moving 239 , 240 Pu through the ground water reservoirs are independent of the processes controlling the cycling of 137 Cs and fresh water. A reasonable linear correlation is found between mean surface-water concentrations and soil burdens. This indicates that the quantities of 239 , 240 Pu migrating to the groundwater surface layers are, to a first approximation, independent of the physical, chemical or biological characteristics of the islands. (auth)

  1. Resuspension studies at Bikini Atoll

    International Nuclear Information System (INIS)

    Shinn, J.H.; Homan, D.N.; Robison, W.L.

    1980-02-01

    The following experiments were conducted on Bikini Atoll to provide key parameters for an assessment of inhalation exposure from plutonium-contaminated dust aerosols: (1) a characterization of background (plutonium activity, dust, plutonium, sea spray, and organic aerosol concentrations); (2) a study of plutonium resuspension from a bare field; (3) a study of plutonium resuspension by traffic; and (4) a study of personal inhalation exposure. Dust concentrations of 21 μg m -3 and sea spray of 34 μg m -3 were the background throughout the Bikini Island except within 50 m of the windward beach. Background concentrations of 239+240 Pu were 60 aCi m -3 in the coconut grove and 264 aCi m -3 over rain-stabilized bare soil. The ratio of plutonium activity in aerosols relative to the activity in underlying soil, defined as the enhancement factor, EF, was typically less than one. Enhancement factors increased about 3.8 as a result of tilling. Plutonium resuspension flux was estimated at 0.49 pCi m -2 year -1 over most of Bikini Island. Aerosol size distributions associated with mass and with plutonium activity were typically log-normal with median aerodynamic diameter 2.44 μm, which decreased to 2.0 μm above freshly tilled soil. The Pu concentration in aerosols collected over disturbed soil increased by a factor of 19.1. Vehicular traffic produced dust pulses typically of 10 s duration, 28 μg m -3 average concentration, and plutonium enhancement factor 2.5. Personal dosimetry showed that enhancement of dust by a worker was a factor of 2.64 for heavy work outdoors and 1.86 for light work in and around houses. Pulmonary deposition of plutonium was calculated for various exposure conditions. The pulmonary deposition ranged from 1476 aCi h -1 to 12 aCi h -1

  2. Terrestrial forest management plan for Palmyra Atoll

    Science.gov (United States)

    Hathaway, Stacie A.; McEachern, Kathryn; Fisher, Robert N.

    2011-01-01

    This 'Terrestrial Forest Management Plan for Palmyra Atoll' was developed by the U.S. Geological Survey (USGS) for The Nature Conservancy (TNC) Palmyra Program to refine and expand goals and objectives developed through the Conservation Action Plan process. It is one in a series of adaptive management plans designed to achieve TNC's mission toward the protection and enhancement of native wildlife and habitat. The 'Terrestrial Forest Management Plan for Palmyra Atoll' focuses on ecosystem integrity and specifically identifies and addresses issues related to assessing the status and distribution of resources, as well as the pressures acting upon them, most specifically nonnative and potentially invasive species. The plan, which presents strategies for increasing ecosystem integrity, provides a framework to implement and track the progress of conservation and restoration goals related to terrestrial resources on Palmyra Atoll. The report in its present form is intended to be an overview of what is known about historical and current forest resources; it is not an exhaustive review of all available literature relevant to forest management but an attempt to assemble as much information specific to Palmyra Atoll as possible. Palmyra Atoll is one of the Northern Line Islands in the Pacific Ocean southwest of the Hawai`ian Islands. It consists of many heavily vegetated islets arranged in a horseshoe pattern around four lagoons and surrounded by a coral reef. The terrestrial ecosystem consists of three primary native vegetation types: Pisonia grandis forest, coastal strand forest, and grassland. Among these vegetation types, the health and extent of Pisonia grandis forest is of particular concern. Overall, the three vegetation types support 25 native plant species (two of which may be extirpated), 14 species of sea birds, six shore birds, at least one native reptile, at least seven native insects, and six native land crabs. Green and hawksbill turtles forage at Palmyra Atoll

  3. Biology of the rodents of Enewetak Atoll

    International Nuclear Information System (INIS)

    Jackson, W.B.; Vessey, S.H.; Bastian, R.K.

    1987-01-01

    Roof rats and Polynesian rats, introduced to the atoll by 20th Century commerce and the Micronesians, respectively, were present allopatrically on the larger islets. Of necessity, they were largely vegetarians. Reproductive cycles were keyed to rainfall patterns. High density populations had high stress indices, including high parasite loads. The rats, at the top of the terrestrial food pyramid, constituted a bioenvironmental monitor that was rarely utilized during the several test programs. Bioconcentration of radioisotopes, especially 137 Cs and 60 Co, occurred; rats implanted with dosimeters were determined to function as environmental radiation monitors. They hypothesized that roof rats on Enjebi survived the nearby nuclear detonation. Analysis of plasma transferrins indicated greater heterozygosity in the northern atoll rat populations. The incidence of oral palatal ridge deformations also was positively correlated with environmental radiation levels, but other gross indications of radiation effect were not found

  4. Geochemistry of transuranic elements at Bikini Atoll

    International Nuclear Information System (INIS)

    Schell, W.R.; Lowman, F.G.; Marshall, R.P.

    1980-01-01

    The distribution of transuranic and other radionuclides in the marine environment at Bikini Atoll was studied to better understand the geochemical cycling of radionuclides produced by nuclear testing between 1946 and 1958. The reef areas, which are washed continually by clean ocean water, have low levels of radionuclide concentrations. Radionuclides are contained in fallout particles of pulverized coral. In the water these particles may dissolve, be transported by currents within the Atoll, or enter the North Equatorial Current by tidal exchange of water in the lagoon. The transuranic elements are distributed widely in sediments over the northwest quadrant of the Atoll, which suggests that this area serves as a settling basin for particles. The distribution of plutonium in the water column indicates that plutonium in the sediments is released to the bottom waters and then is transported and diluted by the prevailing currents. Upon interaction with the lagoon environment, plutonium occurs in several physicochemical states. Laboratory tests and field studies at Bikini show that approximately 15% of the plutonium is associated with the colloidal fraction

  5. Evaluation of plutonium at Enewetak Atoll

    International Nuclear Information System (INIS)

    Wilson, D.W.; Ng, Y.C.; Robison, W.L.

    1975-01-01

    An extensive survey was carried out in 1972 to 1973 to assess the current radiological status of Enewetok Atoll. The radionuclides detected in the Atoll environment were studied for their potential contributions to the dose commitment of the returning population according to several pathways of exposure. Plutonium was detected in air and in the terrestrial and aquatic environment at concentrations that varied from background levels due to world-wide fallout to levels several orders-of-magnitude above. The dose commitments from plutonium via the terrestrial food chain and inhalation vary according to the postulated living pattern. The dosages via marine foods can be expected to be insensitive to living pattern and to exceed those via terrestrial foods. Plutonium would contribute nearly all of the dosage via inhalation, but this pathway ranks low in overall importance compared with the food-chain and external-dose pathways. Although the potential dose from plutonium via all pathways is low relative to that from 60 Co, 90 Sr and 137 Cs, plutonium will still remain in the Atoll environment after the other makor isotopes have decayed away. (author)

  6. Multidecadal shoreline changes of atoll islands in the Marshall Islands

    Science.gov (United States)

    Ford, M.

    2012-12-01

    Atoll islands are considered highly vulnerable to the impacts of continued sea level rise. One of the most commonly predicted outcomes of continued sea level rise is widespread and chronic shoreline erosion. Despite the widespread implications of predicted erosion, the decadal scale changes of atoll island shorelines are poorly resolved. The Marshall Islands is one of only four countries where the majority of inhabited land is comprised of reef and atoll islands. Consisting of 29 atolls and 5 mid-ocean reef islands, the Marshall Islands are considered highly vulnerable to the impacts of sea level rise. A detailed analysis of shoreline change on over 300 islands on 10 atolls was undertaken using historic aerial photos (1945-1978) and modern high resolution satellite imagery (2004-2012). Results highlight the complex and dynamic nature of atoll islands, with significant shifts in shoreline position observed over the period of analysis. Results suggest shoreline accretion is the dominant mode of change on the islands studied, often associated with a net increase in vegetated island area. However, considerable inter- and intra-atoll variability exists with regards to shoreline stability. Findings are discussed with respect to island morphodynamics and potential hazard mitigation and planning responses within atoll settings.

  7. Geohydrology of Enewetak Atoll islands and reefs

    International Nuclear Information System (INIS)

    Buddemeier, R.W.

    1981-01-01

    Extensive tidal studies in island wells and the lagoon at Enewetak Atoll have shown that island ground water dynamics are controlled by a layered aquifer system. The surface aquifer of unconsolidated Holocene material extends to a depth of approximately 15 m, and has a hydraulic conductivity K = 60 m/day. From 15 to 60 m (approximate lagoon depth) the reef structure consists of successive layers of altered Pleistocene materials, with bulk permeability substantially higher than that of the surface aquifer. Because of wave set-up over the windward reef and the limited pass area for outflow at the south end of the atoll, lagoon tides rise in phase with the ocean tides but fall later than the ocean water level. This results in a net lagoon-to-ocean head which can act as the driving force for outflow through the permeable Pleistocene aquifer. This model suggests that fresh water, nutrients or radioactive contaminants found in island ground water or reef interstitial water may be discharged primarily into the ocean rather than the lagoon. Atoll island fresh water resources are controlled by recharge, seawater dilution due to vertical tidal mixing between the surface and deeper aquifers, and by loss due to entrainment by the outflowing water in the deeper aquifers. Estimated lagoon-ot-ocean transit times through the deep aquifer are on the order of a few years, which corresponds well to the freshwater residence time estimates based on inventory and recharge. Islands in close proximity to reef channels have more fresh ground water than others, which is consistent with a locally reduced hydraulic gradient and slower flow through the Pleistocene aquifers

  8. The radiological situation at the atolls of Mururoa and Fangataufa. Summary report

    International Nuclear Information System (INIS)

    1998-01-01

    Between 1966 and 1996, France conducted 193 'experiences nucleaires' (nuclear experiments - a term used by the French authorities to include the full testing of nuclear weapons and the conduct of certain safety trails) above and beneath the atolls of Mururoa and Fangataufa in the Tuamotu Archipelago of French Polynesia. All French testing ceased on 27 January 1996. Before the completion of the last series of tests the Government of France requested the International Atomic Energy Agency (IAEA) to conduct a study to assess the radiological impact of the tests. The IAEA agreed to carry out a study - the Study of the Radiological Situation at the Atolls of Mururoa and Fangataufa - for the purpose of ascertaining whether, as a consequence of the tests, radiological hazards exist now or will exist in the future, and making recommendations on the form, scale and duration of any monitoring, remedial action or follow-up action that might be required. An International Advisory Committee (IAC) was concerned by the Director General of the IAEA to provide scientific direction and guidance to the IAEA in the conduct of the Study and to prepare a report on the Study's findings, conclusions and recommendations. The IAC's first formal meeting took place in Vienna on 13-14 April 1996 and its final one, also in Vienna, on 3-5 February 1998. The Summary Report presents a comprehensive summary of the Main Report, including its findings, conclusions and recommendations. The purpose of this Summary Report on the Study of the Radiological Conditions at the Atolls of Mururoa and Fangataufa is to present a summary account of the Study together with its findings, conclusions and recommendation for the benefit of a wider audience. For a comprehensive scientific account, the reader is referred to the Main Report and the detailed Technical Report for the Study

  9. Atoll-scale patterns in coral reef community structure: Human signatures on Ulithi Atoll, Micronesia.

    Science.gov (United States)

    Crane, Nicole L; Nelson, Peter; Abelson, Avigdor; Precoda, Kristin; Rulmal, John; Bernardi, Giacomo; Paddack, Michelle

    2017-01-01

    The dynamic relationship between reefs and the people who utilize them at a subsistence level is poorly understood. This paper characterizes atoll-scale patterns in shallow coral reef habitat and fish community structure, and correlates these with environmental characteristics and anthropogenic factors, critical to conservation efforts for the reefs and the people who depend on them. Hierarchical clustering analyses by site for benthic composition and fish community resulted in the same 3 major clusters: cluster 1-oceanic (close proximity to deep water) and uninhabited (low human impact); cluster 2-oceanic and inhabited (high human impact); and cluster 3-lagoonal (facing the inside of the lagoon) and inhabited (highest human impact). Distance from village, reef exposure to deep water and human population size had the greatest effect in predicting the fish and benthic community structure. Our study demonstrates a strong association between benthic and fish community structure and human use across the Ulithi Atoll (Yap State, Federated States of Micronesia) and confirms a pattern observed by local people that an 'opportunistic' scleractinian coral (Montipora sp.) is associated with more highly impacted reefs. Our findings suggest that small human populations (subsistence fishing) can nevertheless have considerable ecological impacts on reefs due, in part, to changes in fishing practices rather than overfishing per se, as well as larger global trends. Findings from this work can assist in building local capacity to manage reef resources across an atoll-wide scale, and illustrates the importance of anthropogenic impact even in small communities.

  10. Atoll-scale patterns in coral reef community structure: Human signatures on Ulithi Atoll, Micronesia.

    Directory of Open Access Journals (Sweden)

    Nicole L Crane

    Full Text Available The dynamic relationship between reefs and the people who utilize them at a subsistence level is poorly understood. This paper characterizes atoll-scale patterns in shallow coral reef habitat and fish community structure, and correlates these with environmental characteristics and anthropogenic factors, critical to conservation efforts for the reefs and the people who depend on them. Hierarchical clustering analyses by site for benthic composition and fish community resulted in the same 3 major clusters: cluster 1-oceanic (close proximity to deep water and uninhabited (low human impact; cluster 2-oceanic and inhabited (high human impact; and cluster 3-lagoonal (facing the inside of the lagoon and inhabited (highest human impact. Distance from village, reef exposure to deep water and human population size had the greatest effect in predicting the fish and benthic community structure. Our study demonstrates a strong association between benthic and fish community structure and human use across the Ulithi Atoll (Yap State, Federated States of Micronesia and confirms a pattern observed by local people that an 'opportunistic' scleractinian coral (Montipora sp. is associated with more highly impacted reefs. Our findings suggest that small human populations (subsistence fishing can nevertheless have considerable ecological impacts on reefs due, in part, to changes in fishing practices rather than overfishing per se, as well as larger global trends. Findings from this work can assist in building local capacity to manage reef resources across an atoll-wide scale, and illustrates the importance of anthropogenic impact even in small communities.

  11. CRED REA Algal Assessments, Johnston Atoll 2004 (NODC Accession 0010352)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines as part of Rapid Ecological Assessments conducted at 12 sites at Johnston Atoll in...

  12. Palmyra Atoll Quickbird II Seafloor Mosaic (1.8m)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic habitat maps of the nearshore marine environment of Pamyra Atoll were created by visual interpretation of remotely sensed imagery. The objective of this...

  13. CRED REA Algal Assessments, Palmyra Atoll 2004 (NODC Accession 0010352)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines as part of Rapid Ecological Assessments conducted at 8 sites at Palmyra Atoll in the US...

  14. Palmyra Atoll Quickbird II Terrestrial Mosaic (1.8m)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic habitat maps of the nearshore marine environment of Pamyra Atoll were created by visual interpretation of remotely sensed imagery. The objective of this...

  15. Challenges and Opportunities for Sustainable Tourism Development in Ulithi Atoll

    Directory of Open Access Journals (Sweden)

    Anna Ongaro

    2016-07-01

    Full Text Available This article aims to analyze the tourism potential of Ulithi Atoll, in the Federated States of Micronesia. It identifies possibilities for sustainable tourism development, while taking into account the major issues that threaten the environment, the cultural integrity and the future of the local community. Through a review of existing research and an assessment of the web presence, the study develops a diagnosis of the current situation of the tourism sector in the destination. The tourism potential of Ulithi mainly relies on its beautiful physical environment and authentic cultural heritage, but it is still largely untapped due to limited development. Tourism represents a strategic tool for the economic growth and empowerment of Ulithi community. Presently, however, the atoll’s biggest problem is the recovery from the recent disastrous Typhoon Maysak. Other pressing challenges are climate change and the erosion of traditional knowledge. The study identifies ecotourism and voluntourism as key niche market opportunities for the destination. Encouraging greater participation among the stakeholders and a concrete commitment to sustainability within the strategic plans are some of the recommendations that aim to build the tourism industry in a way that supports the local culture, the natural resources and the way of life.

  16. Processing plutonium-contaminated soil on Johnston Atoll

    International Nuclear Information System (INIS)

    Moroney, K.; Moroney, J. III; Turney, J.

    1994-01-01

    This article describes a cleanup project to process plutonium- and americium-contaminated soil on Johnston Atoll for volume reduction. Thermo Analytical's (TMA's) segmented gate system (SGS) for this remedial operation has been in successful on-site operation since 1992. Topics covered include the basis for development, a description of the Johnston Atoll; the significance of results; the benefits of the technology; applicability to other radiologically contaminated sites. 7 figs., 1 tab

  17. Radiological conditions at Bikini Atoll: Prospects for resettlement

    International Nuclear Information System (INIS)

    1998-01-01

    An international Advisory Group met at IAEA Headquarters in Vienna on 11-15 December 1995 for the purpose of reviewing the current radiological conditions at Bikini Atoll, Republic of the Marshall Islands, and advising on the prospects for rehabilitation of the atoll and resettlement of its indigenous population. The Advisory Group was convened by the IAEA in response to a request for technical assistance from the Government of the Marshall Islands within the framework of IAEA technical co-operation project MHL/9/003, 'Radiological Monitoring in Bikini Atoll'. The primary aim of this review was to assist the Bikinian people to form their own judgement on the radiological conditions at their atoll and on the prospects for resettling there, should they so desire. At the meeting, the Advisory Group benefited greatly from the participation of a delegation from the Marshall Islands. At the request of the Government of the Marshall Islands, the international review was limited to Bikini Atoll and did not extend to other atolls, islands and isles affected by radioactive fallout from the testing. Moreover, within Bikini Atoll, it was concentrated on Bikini Island, where the Bikinian population formerly resided. The review relates to the prevailing radiological circumstances and their implications for the future habitability of the atoll. It is not intended to include the retrospective assessment of the past radiological impact of nuclear testing. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has routinely estimated, and reported to the United Nations General Assembly, radiation levels and effects attributable to nuclear weapon testing, including the tests carried out in the territory of the Marshall Islands. Some of the UNSCEAR estimates have been included in the report, but only for the sake of completeness

  18. Spatial and temporal controls of atoll island inundation: implications for urbanized atolls in the Marshall Islands.

    Science.gov (United States)

    Ford, M.; Becker, J. M.; Merrifield, M. A.

    2012-12-01

    Atoll islands are highly vulnerable to a range of inundation hazards. The impacts of such hazards are expected to be magnified as a result of continued sea-level rise. Both recent and historic inundation events provide unique insights into the requisite conditions necessary to initiate island inundation. A number of recent and historic inundation events are presented in order to examine the oceanographic and meteorological conditions driving inundation of a densely populated, urbanized atoll in the central Pacific. Analysis of inundation events suggests that a number of key drivers contribute to the spatial and temporal extent of island inundation, with unique degrees of predictability and resultant impact signatures apparent on island geomorphology and local anthropogenic activities. Results indicate three distinct drivers of inundation hazards exist. Firstly, tropical storms and typhoons elevate sea level through inverse barometric setup, wind setup and a range of wave driven processes and have caused considerable impact on atolls within the Marshall Islands. Secondly, super-elevated sea level conditions resulting from the combination of seasonal high tides and quasi-cyclical La Nina conditions drive inundation of low-lying lagoon facing coastal areas. Thirdly, long period swell conditions, typically generated by distant storms, can elevate reef-flat water levels through wave setup and infragravity wave oscillations. Such wave conditions can over wash the ocean-facing island ridge, often inundating large sections of the island. Reef-flat wave conditions are tidally modulated, with inundation events typically occurring around high tide. However, the two most recent destructive swell-driven inundation events have occurred while tide levels were significantly lower than spring tide levels, suggesting high water levels are not a necessary prerequisite for wave-driven inundation. The different modes of inundation are discussed and grounded within recent and historic

  19. Migration from atolls as climate change adaptation

    DEFF Research Database (Denmark)

    Birk, Thomas Ladegaard Kümmel; Rasmussen, Kjeld

    2014-01-01

    to migration that reduce the efficacy of positive outcomes to both migrants and their home communities, including high transport costs and problems in gaining access to housing, employment and government services in urban destination areas. If it is accepted that voluntary migration may play a positive role...... that migration currently improves access to financial and social capital, reduces pressure on natural resources and makes island communities less vulnerable to extreme weather events and other shocks — all factors that contribute positively to adaptive capacity. It also shows that there are major barriers...... in adaptation to climate change in exposed atoll communities, addressing some of the barriers to migration seems logical. This may be done by efforts to stimulate migrant income opportunities, by improving migrant living conditions and by improving the transport services to the islands....

  20. External exposure measurements at Bikini Atoll

    International Nuclear Information System (INIS)

    Greenhouse, N.A.; Miltenberger, R.P.; Lessard, E.T.

    1979-01-01

    External exposure rate surveys from 1975 to 1977 on the islands Nam, Eneu and Bikini of Bikini Atoll gave average external exposure rates of 24, 5.7, and 32 μR/hr respectively. The exposure rate on Eneu Island is uniform, whereas those on Bikini and Nam range from 7.0 to 80. μR/hr. Based on an assumed living pattern at Bikini Island, the adult male Bikinian is estimated to be in the presence of an external radiation field corresponding to 16 μR/hr due to debris and fallout from the 1954 BRAVO incident. This corresponds to a 30 year dose equivalent of 2.8 rem

  1. Numerical modeling of atoll island hydrogeology.

    Science.gov (United States)

    Bailey, R T; Jenson, J W; Olsen, A E

    2009-01-01

    We implemented Ayers and Vachers' (1986) inclusive conceptual model for atoll island aquifers in a comprehensive numerical modeling study to evaluate the response of the fresh water lens to selected controlling climatic and geologic variables. Climatic factors include both constant and time-varying recharge rates, with particular attention paid to the effects of El Niño and the associated drought it brings to the western Pacific. Geologic factors include island width; hydraulic conductivity of the uppermost Holocene-age aquifer, which contains the fresh water lens; the depth to the contact with the underlying, and much more conductive, Pleistocene karst aquifer, which transmits tidal signals to the base of the lens; and the presence or absence of a semiconfining reef flat plate on the ocean side. Sensitivity analyses of steady-steady simulations show that lens thickness is most strongly sensitive to the depth to the Holocene-Pleistocene contact and to the hydraulic conductivity of the Holocene aquifer, respectively. Comparisons between modeling results and published observations of atoll island lens thicknesses suggest a hydraulic conductivity of approximately 50 m/d for leeward islands and approximately 400 m/d for windward islands. Results of transient simulations show that lens thickness fluctuations during average seasonal conditions and El Niño events are quite sensitive to island width, recharge rate, and hydraulic conductivity of the Holocene aquifer. In general, the depletion of the lens during drought conditions is most drastic for small, windward islands. Simulation results suggest that recovery from a 6-month drought requires about 1.5 years.

  2. Clipperton, a possible future for atoll lagoons

    Science.gov (United States)

    Charpy, L.; Rodier, M.; Couté, A.; Perrette-Gallet, C.; Bley-Loëz, C.

    2010-09-01

    Closure of the Clipperton Island atoll (10°17' N 109°13' W), now a meromictic lake, is estimated to have occurred between 1839 and 1849. It was still closed in 2005. Brackish waters in the upper layer (0-10 m) were oxygenated, while saline waters in the deep layer (>20 m) were anoxic. Allowing for the methodological difficulties of earlier measurements, the physical characteristics of the lagoon did not seem to have changed significantly since the last expedition (1980). The intermediate layer between brackish and saline waters was characterized by a strong density gradient and a temperature inversion of up to 1.6°C. Microbial activity, water exchange between the deep layer and surrounding oceanic waters and the geothermal flux hypothesis are discussed. The low DIN and SRP concentrations observed in the upper layer, despite high nutrient input by seabird droppings, reflect the high nutrient uptake by primary producers as attested by the elevated overall gross primary production (6.6 g C m-2 day-1), and high suspended photosynthetic biomass (2.23 ± 0.23 μg Chl a l-1) and production (263 ± 27 μg C l-1 day-1). Phytoplankton composition changed in 67 years with the advent of new taxa and the disappearance of previously recorded species. The freshwater phytoplanktonic community comprised 43 taxa: 37 newly identified during the expedition and 6 previously noted; 16 species previously found were not seen in 2005. The closure of the lagoon, combined with the positive precipitation-evaporation budget characteristic of the region, has induced drastic changes in lagoon functioning compared with other closed atolls.

  3. The radiological situation at the atolls of Mururoa and Fangataufa. Main report

    International Nuclear Information System (INIS)

    1998-01-01

    Between 1966 and 1996, France conducted 193 'experiences nucleaires' (nuclear experiments - a term used by the French authorities to include the full testing of nuclear weapons and the conduct of certain safety trails) above and beneath the atolls of Mururoa and Fangataufa in the Tuamotu Archipelago of French Polynesia. All French testing ceased on 27 January 1996. Before the completion of the last series of tests the Government of France requested the International Atomic Energy Agency (IAEA) to conduct a study to assess the radiological impact of the tests. The IAEA agreed to carry out a study - the Study of the Radiological Situation at the Atolls of Mururoa and Fangataufa - for the purpose of ascertaining whether, as a consequence of the tests, radiological hazards exist now or will exist in the future, and making recommendations on the form, scale and duration of any monitoring, remedial action or follow-up action that might be required. An International Advisory Committee (IAC) was convened by the Director General of the IAEA to provide scientific direction and guidance to the IAEA in the conduct of the Study and to prepare a report on the Study's findings, conclusions and recommendations. The IAC's first formal meeting took place in Vienna on 13-14 April 1996 and its final one, also in Vienna, on 3-5 February 1998. This publication constitutes one of several reports of the IAC to Director General describing the conduct of the Study and its findings, conclusions and recommendations. The French Government provided much of the information used in the Study. This information was independently evaluated by Study participants and, where practicable, validated. In addition to the information provided by the French Government, a small amount of information had been published in the open literature on measured levels of certain radionuclides ( 60 Co, 90 Sr, 137 Cs and 239+240 Pu) in the environment of the atolls, and reports of three scientific missions to the atolls

  4. Atoll mangroves and associated flora from Republic of Maldives, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Jagtap, T.G.; Untawale, A.G.

    of the north atolls. Male' atoll was totally devoid of mangroves due to their large scale reclamation mainly for urbanisation and tourism. Mangrove flora comprised of 12 species and was dominated by Bruguiera cylindrica followed by Lumnitzera racemosa, Ceriops...

  5. Estimating the Ground Water Resources of Atoll Islands

    Directory of Open Access Journals (Sweden)

    Arne E. Olsen

    2010-01-01

    Full Text Available Ground water resources of atolls, already minimal due to the small surface area and low elevation of the islands, are also subject to recurring, and sometimes devastating, droughts. As ground water resources become the sole fresh water source when rain catchment supplies are exhausted, it is critical to assess current groundwater resources and predict their depletion during drought conditions. Several published models, both analytical and empirical, are available to estimate the steady-state freshwater lens thickness of small oceanic islands. None fully incorporates unique shallow geologic characteristics of atoll islands, and none incorporates time-dependent processes. In this paper, we provide a review of these models, and then present a simple algebraic model, derived from results of a comprehensive numerical modeling study of steady-state atoll island aquifer dynamics, to predict the ground water response to changes in recharge on atoll islands. The model provides an estimate thickness of the freshwater lens as a function of annual rainfall rate, island width, Thurber Discontinuity depth, upper aquifer hydraulic conductivity, presence or absence of a confining reef flat plate, and in the case of drought, time. Results compare favorably with published atoll island lens thickness observations. The algebraic model is incorporated into a spreadsheet interface for use by island water resources managers.

  6. Individual Radiation Protection Monitoring in the Marshall Islands. Utrok Atoll (2010-2012)

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, T. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kehl, S. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martinelli, R. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hickman, R. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hickman, D. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tumey, S. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brown, T. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Langston, R. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tamblin, M. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tibon, S. [Utrok Whole Body Counting Facility, Majuro Atoll (Republic of the Marshall Islands); Chee, L. [Utrok Whole Body Counting Facility, Majuro Atoll (Republic of the Marshall Islands); Aisek, Jr., A. [Utrok Whole Body Counting Facility, Majuro Atoll (Republic of the Marshall Islands); DeDrum, Z. [Utrok Whole Body Counting Facility, Majuro Atoll (Republic of the Marshall Islands); Mettao, M. [Utrok Whole Body Counting Facility, Majuro Atoll (Republic of the Marshall Islands); Henson, J. [Utrok Whole Body Counting Facility, Majuro Atoll (Republic of the Marshall Islands)

    2014-12-15

    As a hard copy supplement to the Marshall Islands Program website (https://marshallislands.llnl.gov), this document provides an overview of the individual radiological surveillance monitoring program established in support of residents of Utrōk Atoll and nonresident citizens of the Utrōk Atoll population group, along with full disclosure of verified measurement data (2010-2012). The Utrōk Atoll Whole Body Counting Facility has been temporarily stationed on Majuro Atoll and, in cooperation with the Utrōk Atoll Local Government, serves as a national radiological facility open to the general public.

  7. Neogene biostratigraphy and paleoenvironments of Enewetak Atoll, equatorial Pacific Ocean

    Science.gov (United States)

    Cronin, T. M.; Bybell, L.M.; Brouwers, E.M.; Gibson, T.G.; Margerum, R.; Poore, R.Z.

    1991-01-01

    Micropaleontologic analyses of Neogene sediments from Enewetak Atoll, Marshall Islands, provide data on the age of lagoonal deposits, stratigraphic disconformities and the paleoenvironmental and subsidence history of the atoll. Benthic foraminifers, planktic foraminifers, calcareous nannofossils and ostracodes were studied from six boreholes, the deepest penetrating 1605 feet below the lagoon floor into upper Oligocene strata. The Oligocene-Miocene boundary occurs at about 1200 ft below the lagoon floor. The early and middle Miocene is characterized by brief periods of deposition and numerous hiatuses. Ostracodes and benthic foraminifers indicate a shallow-marine reefal environment with occasional brackish water conditions. Upper Miocene and lower Pliocene deposits placed in calcareous nannofossil Zones NN9-15 and in planktic foraminifer Zones N16-19 contain species-rich benthic microfaunas which indicate alternating reefal and brackish water mangrove environments. The upper Pliocene contains at least two major depositional hiatuses that coincide with a major faunal turnover in benthic foraminiferal and ostracode assemblages. The Quaternary is characterized by benthic microfaunas similar to those of modern atoll lagoons and is punctuated by at least 11 disconformities which signify periods of low sea level. Atoll subsidence rates during the last 10 Ma averaged 30 to 40 m/m.y. ?? 1991 Elsevier Science Publishers B.V. All rights reserved.

  8. Report on a few Octocorals from Eniwetok Atoll, Marshall Islands

    NARCIS (Netherlands)

    Verseveldt, J.

    1972-01-01

    In 1969 Dr. Arthur G. Humes, Boston University, Massachusetts, U.S.A., collected a number of octocorals at Eniwetok Atoll, Marshall Islands. He found that most of these corals were the hosts of copepods, just like the corals collected by him in the waters north-west of Madagascar (vide Verseveldt,

  9. Providing an authorization for an ex gratia payment to the people of Bikini Atoll, in the Marshall Islands of the Trust Territory of the Pacific Islands. Senate, Ninety-Fourth Congress, First Session, June 2, 1975

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Proposed legislation for payment of dollars 3 million ex gratia to the people of Bikini Atoll due to their relocation resulting from nuclear-weapons testing and successive contamination of their homeland is presented. The Committee on Interior and Insular Affairs recommends passage

  10. A history of the people of Bikini following nuclear weapons testing in the Marshall Islands: with recollections and views of elders of Bikini Atoll.

    Science.gov (United States)

    Niedenthal, J

    1997-07-01

    The people of Bikini Atoll were moved from their homeland in 1946 to make way for the testing of 23 nuclear weapons by the United States government, beginning with the world's fourth atomic detonation. The subsequent half-century exodus of the Bikini people included a 2-y stay on Rongerik Atoll, where near starvation resulted, and a 6-mo sojourn on Kwajalein Atoll, where they lived in tents beside a runway used by the U.S. military. In 1948, they were finally relocated to Kili, a small, isolated, 200-acre island owned by the U.S. Trust Territory government. Numerous hardships have been faced there, not the least of which was the loss of skills required for self-sustenance. Located 425 miles south of Bikini, Kili Island is without a sheltered lagoon. Thus for six months of the year, fishing and sailing become futile endeavors. Because of the residual radioactive contamination from the nuclear testing, the majority of the Bikinian population still resides on Kili today. One attempt was made to resettle Bikini in the late 1960's when President Lyndon B. Johnson, on recommendations from the Atomic Energy Commission, declared Bikini Atoll safe for habitation. In 1978, however, it was discovered by the U.S. Department of Energy that in the span of only one year, some of the returned islanders were showing a 75% increase in their body burdens of 137Cs. In 1978, the people residing on Bikini were moved again, this time to a small island in Majuro Atoll. In the early 1980's, the Bikinians filed a class action lawsuit against the U.S. government for damages arising out of the nuclear testing program. Although the claim was dismissed, eventually a $90 million trust fund was established for their local government. Since then the leaders of the people of Bikini residing on Kili Island and Majuro Atoll have been confronted with the immense responsibility of determining how to clean their atoll while at the same time maintaining the health and welfare of their displaced

  11. Audit Report. Johnston Atoll Chemical Agent Disposal System Preparation for Year 2000

    National Research Council Canada - National Science Library

    1998-01-01

    .... The overall audit objective was to determine whether the Johnston Atoll Chemical Agent Disposal System was adequately preparing its information technology systems to resolve date-processing issues...

  12. Causes of mortality of albatross chicks at Midway Atoll

    Science.gov (United States)

    Sileo, L.; Sievert, P.R.; Samuel, M.D.

    1990-01-01

    As part of an investigation of the effect of plastic ingestion on seabirds in Hawaii, we necropsied the carcasses of 137 Laysan albatross (Diomedea immutabilis) chicks from Midway Atoll in the Pacific Ocean during the summer of 1987. Selected tissues were collected for microbiological, parasitological, toxicological or histopathological examinations. Dehydration was the most common cause of death. Lead poisoning, trauma, emaciation (starvation) and trombidiosis were other causes of death; nonfatal nocardiosis and avian pox also were present. There was no evidence that ingested plastic caused mechanical lesions or mortality in 1987, but most of the chicks had considerably less plastic in them than chicks from earlier years. Human activity (lead poisoning and vehicular trauma) caused mortality at Midway Atoll and represented additive mortality for pre-fledgling albatrosses.

  13. Observations of infragravity motions for reef fringed islands and atolls

    Science.gov (United States)

    Becker, J. M.; Merrifield, M. A.; Ford, M.

    2012-12-01

    The frequency of flooding events that affect low lying islands and atolls in the Pacific is expected to increase under current sea level rise projections. Infragravity (IG) motions, with periods ranging from approximately 25 to 400 seconds, are an important component of wave driven flooding events for reef fringed islands and atolls. The IG variability during wave events is analyzed and interpreted dynamically from pressure and current observations at four cross-reef transects in the North Pacific Ocean that include sites in the Republic of the Marshall Islands and Guam. The IG motions are shown to depend upon the spectral properties of the incident wave forcing and reef flat characteristics that include reef flat length (ranging from 100m to 450m at the four sites) and total water level due to setup and tides. A small inundation event at one of the sites is shown to occur due to large shoreline infragravity energy.

  14. Statistical aspects of the cleanup of Enewetak Atoll

    International Nuclear Information System (INIS)

    Giacomini, J.J.; Miller, F.L. Jr.

    1981-01-01

    The Desert Research Institute participated in the Enewetak Atoll Radiological Cleanup by providing data-base management and statistical analysis support for the Department of Energy team. The data-base management responsibilities included both design and implementation of a system for recording (in machine-retrievable form) all radiological measurements made during the cleanup, excluding personnel dosimetry. Statistical analyses were performed throughout the cleanup and were used to guide excavation activities

  15. beta- and gamma-Comparative dose estimates on Eniwetok Atoll

    Energy Technology Data Exchange (ETDEWEB)

    Crase, K.W.; Gudiksen, P.H.; Robison, W.L.

    1982-05-01

    Eniwetok Atoll is one of the Pacific atolls used for atmospheric testing of U.S. nuclear weapons. Beta dose and gamma-ray exposure measurements were made on two islands of the Eniwetok Atoll during July-August 1976 to determine the beta and low energy gamma-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a beta-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to beta- or low energy gamma-contribution. The contribution at any particular site, however, is somewhat dependent on ground cover, since a minimal amount of vegetation will reduce it significantly from that over bare soil, but thick stands of vegetation have little effect on any further reductions. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey (En73). Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the beta's or low energy gamma's, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose.

  16. 78 FR 12015 - Western Pacific Fisheries; Fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll...

    Science.gov (United States)

    2013-02-21

    ... Islands, and Rose Atoll Marine National Monuments AGENCY: National Marine Fisheries Service (NMFS..., Pacific Remote Islands, and Rose Atoll Marine National Monuments. The proposed rule is intended to...). Proclamation 8337 of January 6, 2009, ``Establishment of the Rose Atoll Marine National Monument'' (74 FR 1577...

  17. 78 FR 7385 - Western Pacific Fisheries; Fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll...

    Science.gov (United States)

    2013-02-01

    ...-BA98 Western Pacific Fisheries; Fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll... Presidential proclamations that created the Marianas Trench, Pacific Remote Islands, and Rose Atoll Marine..., 2009). Proclamation 8337 of January 6, 2009, ``Establishment of the Rose Atoll Marine National Monument...

  18. 78 FR 32996 - Western Pacific Fisheries; Fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll...

    Science.gov (United States)

    2013-06-03

    ... Islands, and Rose Atoll Marine National Monuments AGENCY: National Marine Fisheries Service (NMFS..., and Rose Atoll Marine National Monuments. The intent of this rule is to implement fishery management... Islands Monument, and Proclamation 8337 established the Rose Atoll Monument. The Proclamations define the...

  19. 77 FR 61426 - Rose Atoll National Wildlife Refuge, American Samoa; Draft Comprehensive Conservation Plan and...

    Science.gov (United States)

    2012-10-09

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R1-R-2012-N171; 1265-0000-10137-S3] Rose... Rose Atoll National Wildlife Refuge (NWR/refuge) for public review and comment. In the Draft CCP/EA, [email protected] . Include ``Rose Atoll National Wildlife Refuge Draft CCP/EA'' in the subject line of the...

  20. Evaluation of atrazine plus isoxaflutole (Atoll®) mixture for weed ...

    African Journals Online (AJOL)

    Field experiments were set up in three ecological zones of southwestern Nigeria to evaluate the effectiveness of Atoll® (atrazine + isoxaflutole), a new herbicide mixture, for weed control in maize. Crop i njury rating indicated pronounced phytotoxic effect on crops from 1.34 to 1.61 kg a.i. ha-1 Atoll in all locations. Acceptable ...

  1. 2006 Reson 8101ER Multibeam Sonar Data from Cruise AHI-06-09 - Kure Atoll, Pearl and Hermes Atoll and Kauai Island

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reson 8101ER multibeam Data were collected from 23 June to 19 July 2006 aboard NOAA Survey Launch Acoustic Habitat Investigator (AHI) at Kure Atoll, Pearl and Hermes...

  2. Resettlement of Bikini Atoll: US nuclear test site

    International Nuclear Information System (INIS)

    Robison, W.; Conrado, C.; Stuart, M.; Stoker, A.; Hamilton, T.

    1999-01-01

    Bikini Atoll was one of two sites in the Marshall Islands that were used in the 1950's by the United States for testing nuclear weapons. The testing produced widespread radioactive contamination in Bikini and much of the Northern Marshall Islands. The Bikini people, relocated in 1946 before the test program began, have long desired to return to their homeland. Coral soil on Bikini Island makes cesium-137 ( 137 Cs) much more available for plant uptake than do soils of North America and Europe. Hence, when locally grown crops mature and become available for consumption, the resulting body burden of 137 Cs and the associated doses to humans exceeds federal guidelines. The dose from the terrestrial food ingestion pathway dominates all other pathways and contributes about 90% of the total dose to returning residents. We are, therefore, involved in cost-effective efforts to reduce the dose associated with resettlement. We have evaluated several measures, in addition to soil removal, to eliminate 137 Cs from the soil and to reduce its uptake into food crops. The most effective, and the easiest to implement, is the application of potassium to the atoll soils. A dramatic reduction in 137 Cs occurs in tropical fruits after applications of potassium-rich fertilizer to experimental soil plots. This treatment reduces the associated ingestion dose to about 5% of the pre-treatment levels, and this option avoids removal of the organic-rich surface soils. In addition, the added potassium increases plant productivity. We are now focusing on determining the duration of the effects of potassium treatment on 137 Cs uptake into plants, and the rate of environmental loss of 137 Cs in the atoll ecosystem. (author)

  3. Lingering radioactivity at the Bikini and Enewetak Atolls.

    Science.gov (United States)

    Buesseler, Ken O; Charette, Matthew A; Pike, Steven M; Henderson, Paul B; Kipp, Lauren E

    2018-04-15

    We made an assessment of the levels of radionuclides in the ocean waters, seafloor and groundwater at Bikini and Enewetak Atolls where the US conducted nuclear weapons tests in the 1940's and 50's. This included the first estimates of submarine groundwater discharge (SGD) derived from radium isotopes that can be used here to calculate radionuclide fluxes in to the lagoon waters. While there is significant variability between sites and sample types, levels of plutonium ( 239,240 Pu) remain several orders of magnitude higher in lagoon seawater and sediments than what is found in rest of the world's oceans. In contrast, levels of cesium-137 ( 137 Cs) while relatively elevated in brackish groundwater are only slightly higher in the lagoon water relative to North Pacific surface waters. Of special interest was the Runit dome, a nuclear waste repository created in the 1970's within the Enewetak Atoll. Low seawater ratios of 240 Pu/ 239 Pu suggest that this area is the source of about half of the Pu in the Enewetak lagoon water column, yet radium isotopes suggest that SGD from below the dome is not a significant Pu source. SGD fluxes of Pu and Cs at Bikini were also relatively low. Thus radioactivity associated with seafloor sediments remains the largest source and long term repository for radioactive contamination. Overall, Bikini and Enewetak Atolls are an ongoing source of Pu and Cs to the North Pacific, but at annual rates that are orders of magnitude smaller than delivered via close-in fallout to the same area. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Population pressure on coral atolls: trends and approaching limits.

    Science.gov (United States)

    Rapaport, M

    1990-09-01

    Trends and approaching limits of population pressure on coral atolls is discussed by examining the atoll environment in terms of the physical geography, the production systems, and resource distribution. Atoll populations are grouped as dependent and independent, and demographic trends in population growth, migraiton, urbanization, and political dependency are reviewed. Examination of the carrying capacity includes a dynamic model, the influences of the West, and philopsophical considerations. The carrying capacity is the "maximal population supportable in a given area". Traditional models are criticized because of a lack in accounting for external linkages. The proposed model is dynamic and considers perceived needs and overseas linkages. It also explains regional disparities in population distribution, and provides a continuing model for population movement from outer islands to district centers and mainland areas. Because of increased expectations and perceived needs, there is a lower carrying capacity for outlying areas, and expanded capacity in district centers. This leads to urbanization, emigration, and carrying capacity overshot in regional and mainland areas. Policy intervention is necessary at the regional and island community level. Atolls, which are islands surrounding deep lagoons, exist in archipelagoes across the oceans, and are rich in aquatic life. The balance in this small land area with a vulnerable ecosystem may be easily disturbed by scarce water supplies, barren soils, rising sea levels in the future, hurricanes, and tsunamis. Traditionally, fisheries and horticulture (pit-taro, coconuts, and breadfruit) have sustained populations, but modern influences such as blasting, reef mining, new industrial technologies, population pressure, and urbanization threaten the balance. Population pressure, which has lead to pollution, epidemics, malnutrition, crime, social disintegration, and foreign dependence, is evidenced in the areas of Tuvalu, Kiribati

  5. Electromagnetic methods for mapping freshwater lenses on Micronesian atoll islands

    Science.gov (United States)

    Anthony, S.S.

    1992-01-01

    The overall shape of freshwater lenses can be determined by applying electromagnetic methods and inverse layered-earth modeling to the mapping of atoll island freshwater lenses. Conductivity profiles were run across the width of the inhabited islands at Mwoakilloa, Pingelap, and Sapwuahfik atolls of the Pohnpei State, Federated States of Micronesia using a dual-loop, frequency-domain, electromagnetic profiling system. Six values of apparent conductivity were recorded at each sounding station and were used to interpret layer conductivities and/or thicknesses. A three-layer model that includes the unsaturated, freshwater, and saltwater zones was used to simulate apparent-conductivity data measured in the field. Interpreted results were compared with chloride-concentration data from monitoring wells and indicate that the interface between freshwater and saltwater layers, defined from electromagnetic data, is located in the upper part of the transition zone, where the chloride-concentration profile shows a rapid increase with depth. The electromagnetic method can be used to interpret the thickness of the freshwater between monitoring wells, but can not be used to interpret the thickness of freshwater from monitoring wells to the margin of an island. ?? 1992.

  6. Baseline for beached marine debris on Sand Island, Midway Atoll

    Science.gov (United States)

    Ribic, Christine; Seba B. Sheavly,; John Klavitter,

    2012-01-01

    Baseline measurements were made of the amount and weight of beached marine debris on Sand Island, Midway Atoll, June 2008–July 2010. On 23 surveys, 32,696 total debris objects (identifiable items and pieces) were collected; total weight was 740.4 kg. Seventy-two percent of the total was pieces; 91% of the pieces were made of plastic materials. Pieces were composed primarily of polyethylene and polypropylene. Identifiable items were 28% of the total; 88% of the identifiable items were in the fishing/aquaculture/shipping-related and beverage/household products-related categories. Identifiable items were lowest during April–August, while pieces were at their lowest during June–August. Sites facing the North Pacific Gyre received the most debris and proportionately more pieces. More debris tended to be found on Sand Island when the Subtropical Convergence Zone was closer to the Atoll. This information can be used for potential mitigation and to understand the impacts of large-scale events such as the 2011 Japanese tsunami.

  7. beta. and. gamma. -comparative dose estimates on Enewetak Atoll

    Energy Technology Data Exchange (ETDEWEB)

    Crase, K.W.; Gudiksen, P.H.; Robison, W.L. (California Univ., Livermore (USA). Lawrence Livermore National Lab.)

    1982-05-01

    Enewetak Atoll in the Pacific is used for atmospheric testing of U.S. nuclear weapons. Beta dose and ..gamma..-ray exposure measurements were made on two islands of the Enewetak Atoll during July-August 1976 to determine the ..beta.. and low energy ..gamma..-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a ..beta..-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to ..beta..- or low energy ..gamma..-contribution. The contribution at any particular site, however, is reduced by vegetation. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey. Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the ..beta..'s or low energy ..gamma..'s, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose.

  8. Plutonium and americium behavior in coral atoll environments

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Wong, K.M.; Jokela, T.A.; Brunk, J.L.; Eagle, R.J.

    1984-01-01

    Inventories of 239+240 Pu and 241 Am greatly in excess of global fallout levels persist in the benthic environments of Bikini and Enewetak Atolls. Quantities of 239+240 Pu and lesser amounts of 241 Am are continuously mobilizing from these sedimentary reservoirs. The amount of 239+240 Pu mobilized to solution at any time represents 0.08 to 0.09% of the sediment inventories to a depth of 16 cm. The mobilized 239+240 Pu has solute-like characteristics and different valence states coexist in solution - the largest fraction of the soluble plutonium is in an oxidized form (+V,VI). The adsorption of plutonium to sediments is not completely reversible because of changes that occur in the relative amounts of the mixed oxidation states in solution with time. Further, any characteristics of 239+240 Pu described at one location may not necessarily be relevant in describing its behavior elsewhere following mobilization and migration. The relative amounts of 241 Am to 239+240 Pu in the sedimentary deposits at Enewetak and Bikini may be altered in future years because of mobilization and radiological decay. Mobilization of 239+240 Pu is not a process unique to these atolls, and quantities in solution derived from sedimentary deposits can be found at other global sites. These studies in the equatorial Pacific have significance in assessing the long-term behavior of the transuranics in any marine environment. 22 references, 1 figure, 13 tables

  9. Hydrogeology and management of freshwater lenses on atoll islands: Review of current knowledge and research needs

    Science.gov (United States)

    Werner, Adrian D.; Sharp, Hannah K.; Galvis, Sandra C.; Post, Vincent E. A.; Sinclair, Peter

    2017-08-01

    On atoll islands, fresh groundwater occurs as a buoyant lens-shaped body surrounded by saltwater derived from the sea, forming the main freshwater source for many island communities. A review of the state of knowledge of atoll island groundwater is overdue given their susceptibility to adverse impacts, and the task to address water access and sanitation issues within the United Nations' Sustainable Development Goals framework before the year 2030. In this article, we review available literature to summarise the key processes, investigation techniques and management approaches of atoll island groundwater systems. Over fifty years of investigation has led to important advancements in the understanding of atoll hydrogeology, but a paucity of hydrogeological data persists on all but a small number of atoll islands. We find that the combined effects of buoyancy forces, complex geology, tides, episodic ocean events, strong climatic variability and human impacts create highly dynamic fresh groundwater lenses. Methods used to quantify freshwater availability range from simple empirical relationships to three-dimensional density-dependent models. Generic atoll island numerical models have proven popular in trying to unravel the individual factors controlling fresh groundwater lens behaviour. Major challenges face the inhabitants and custodians of atoll island aquifers, with rising anthropogenic stresses compounded by the threats of climate variability and change, sea-level rise, and some atolls already extracting freshwater at or above sustainability limits. We find that the study of atoll groundwater systems remains a critical area for further research effort to address persistent knowledge gaps, which lead to high uncertainties in water security issues for both island residents and surrounding environs.

  10. Propiedades fisicoquímicas y sensoriales de harinas para preparar atole de amaranto

    OpenAIRE

    Contreras López, Elizabeth; Jaimez Ordaz, Judith; Porras Martínez, Griselda; Juárez Santillán, Luis Felipe; Añorve Morga, Javier; Villanueva Rodríguez, Socorro

    2010-01-01

    El atole es una bebida prehispánica mexicana tradicionalmente preparada con maíz; sin embargo cereales como el arroz y el amaranto también han sido usados empleados. El objetivo fue caracterizar las propiedades fisicoquímicas y sensoriales de una harina para preparar una bebida (atole) a base de amaranto a fin de determinar su aporte nutricional. El análisis bromatológico del atole de amaranto y de las marcas comerciales (a base de maíz y arroz) fue realizado siguiendo las técnicas de la AOAC...

  11. CRED REA Coral Population Parameters at Palmyra Atoll, Line Islands, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Palmyra Atoll in the...

  12. CRED REA Coral Population Paramaters at Rose Atoll, American Samoa, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 1 or 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 11 sites at Rose Atoll in...

  13. CRED REA Coral Population Parameters at Rose Atoll, American Samoa, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 12 sites at Rose Atoll in American...

  14. CRED REA Coral Population Parameters at Kure Atoll, Northwestern Hawaiiian Islands, 2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Kure Atoll in the...

  15. CRED REA Coral Population Parameters at Johnston Atoll, Pacific Remote Island Areas (PRIAs) in 2008

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 4 sites at Johnston Atoll in the...

  16. CRED REA Coral Population Parameters at Pearl and Hermes Atoll, NW Hawaiian Islands (NWHI), 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 13 sites at Pearl and Hermes Atoll...

  17. Marine species survey of Johnson Atoll, Central Pacific Ocean June 2000 (NODC Accession 0000697)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The marine biota of Johnston atoll was surveyed for nonindigenous species in June, 2000 with observations and collections made by investigators using Scuba. Eleven...

  18. CRED REA Fish Team Belt Transect Surveys at Kure Atoll 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Kure Atoll in October,...

  19. Formation of Atoll Garnets in the UHP Eclogites of the Tso Morari ...

    Indian Academy of Sciences (India)

    7

    across the studied atoll grains show elemental variations with higher concentrations of Ca and. 10 ...... from a single eclogite outcrop in the complex and probably represent a case of accidental. 28 ... Textural and compositional relations in the.

  20. CRED REA Algal Assessments, Pearl and Hermes Atoll, Northwestern Hawaiian Islands, 2002 (NODC Accession 0010352)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines as part of Rapid Ecological Assessments conducted at 14 sites at Pearl and Hermes Atoll...

  1. CRED REA Coral Population Parameters at Midway Atoll, Northwestern Hawaiiian Islands, 2002

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Midway Atoll in the...

  2. CRED REA Fish Team Stationary Point Count Surveys at Rose Atoll, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments conducted at 12 sites at Rose Atoll in American Samoa...

  3. Benthic Habitat Maps for Rose Atoll Marine National Monument in American Samoa from 2004 to 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic habitat maps for Rose Atoll, American Samoa were derived from high resolution, multispectral satellite imagery for 2004, 2006, and 2010. The benthic habitat...

  4. Marine macrophytes of Minicoy (Lakshadweep) coral atoll of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Jagtap, T.G.

    Thirty-seven species of marine algae, belonging to 31 genera 5 seagrass species and one mangrove species, were recorded from Minicoy Atoll. The predominant seaweeds observed were Enteromorpha clathrata, Caulerpa species, Ulva lactuca, Halimeda...

  5. CRED REA Coral Population Parameters at Kure Atoll, Northwestern Hawaiiian Islands, 2002

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Kure Atoll in the...

  6. Marine Species Survey of Johnston Atoll, Central Pacific Ocean, June 2000 (NODC Accession 0000670)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The marine biota of Johnston atoll was surveyed for non-indigenous species in June, 2000 with observations and collections made by investigators using Scuba. Eleven...

  7. On the occurrence of Bullia tranquebarica (Roding) Nassaridae (Gastropoda) in Kavaratti atoll (Lakshadweep)

    Digital Repository Service at National Institute of Oceanography (India)

    Namboodiri, P.N.; Sivadas, P.

    A live buccinid gastropod Bullia tranquebarica belonging to family Nassaridae was collected from Kavaratti atoll in Lakshadweep island of Indian Ocean. Interesting pattern of its distribution is described. This is the second record of occurrence...

  8. Whale shark economics: a valuation of wildlife tourism in South Ari Atoll, Maldives

    KAUST Repository

    Cagua, Edgar F.; Collins, Neal; Hancock, James; Rees, Richard

    2014-01-01

    Whale sharks attract large numbers of tourists, divers and snorkelers each year to South Ari Atoll in the Republic of Maldives. Yet without information regarding the use and economic extent of the attraction, it is difficult to prioritize

  9. Studies on the intertidal macrofauna of the sandy beach at Kavarati atoll (Lakshadweep)

    Digital Repository Service at National Institute of Oceanography (India)

    Narayanan, B.; Sivadas, P.

    The distribution of macrofauna in Kavaratti Atoll is studied in the intertidal region for over a period of 13 months. Several diversity in the faunal composition was not observed. The polychaete Scoloplos sp. and the bivalve Mesodesma glabratum were...

  10. CRED REA Algal Assessments, Pearl and Hermes Atoll, Northwestern Hawaiian Islands 2003 (NODC Accession 0010352)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines as part of Rapid Ecological Assessments conducted at 15 sites at Pearl and Hermes Atoll...

  11. CRED REA Coral Population Parameters at Kure Atoll, NW Hawaiian Islands (NWHI), 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Kure Atoll in the NW...

  12. CRED REA Coral Population Parameters at Palmyra Atoll, Pacific Remote Island Areas (PRIAs), 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 13 sites at Palmyra Atoll in the...

  13. CRED REA Fish Team Belt Transect Survey at Swains Atoll, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 8 sites at Swains Atoll in...

  14. CRED REA Fish Team Stationary Point Count Surveys at Midway Atoll, 2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Midway Atoll in July and...

  15. CRED REA Fish Team Stationary Point Count Surveys at Kure Atoll, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Kure Atoll in October, 2004...

  16. CRED REA Coral Population Parameters at Midway Atoll, Northwestern Hawaiian Islands, 2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Midway Atoll in the...

  17. CRED REA Algal Assessments, Midway Atoll, Northwestern Hawaiian Islands 2003 (NODC Accession 0010352)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines as part of Rapid Ecological Assessments conducted at 9 sites at Midway Atoll in the...

  18. CRED REA Algal Assessments, Midway Atoll, Northwestern Hawaiian Islands 2004 (NODC Accession 0010352)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines as part of Rapid Ecological Assessments conducted at 9 sites at Midway Atoll in the...

  19. 2007 Reson 8101ER Multibeam Sonar Data from Cruise AHI0701 - Wake Atoll

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reson 8101ER multibeam Data were collected between 19 April - 9 May 2007 aboard NOAA Survey Launch Acoustic Habitat Investigator (AHI) at Wake Atoll, Western Pacific...

  20. Peregrine falcon predation of endangered Laysan teal and Laysan Finches on remote Hawaiian atolls

    Science.gov (United States)

    Reynolds, Michelle H.; Nash, Sarah A.B.; Courtot, Karen

    2015-01-01

    We report the first records of Peregrine falcon (Falco peregrinus) predation on endangered Laysan teal (or duck; Anas laysanensis) and predation on endangered Laysan finches (Telespiza cantans). At Midway Atoll, vagrant Peregrine falcons killed ≥4% of a newly translocated Laysan teal population in 2006 and ≥2% in 2008. On Laysan Island during 2008–2009, remains of >76 Laysan finches (<1% of the population) were found at peregrine perches. On Midway Atoll, all depredated Laysan teal and other seabirds were recovered at kill sites on tarmac (runways). If the frequency or duration of vagrant raptors visitation increases at small atolls, this could pose a mortality risk to consider, especially during proposed translocations of endangered species. Vegetation restoration of abandoned runways near wetlands at Midway Atoll would provide cover and may help reduce mortality of endangered species due to vagrant raptors.

  1. Assessment of coastal erosion and quantification of land loss on Western Pacific atolls during the last 50 years

    Science.gov (United States)

    Taborosi, Danko; Zega, Mojca; Jenson, John W.

    2010-05-01

    others, and that land is not always eroding but in some cases accreting. We are currently engaged in a systematic survey of islands across the region in order to differentiate local problems from wide-ranging phenomena and gain insight into the temporal and geospatial "big picture." The direct aim is to comprehensively and more precisely assess coastal erosion and quantify changes in land area of different islands over the past 50 years. The project consists of fieldwork and GIS analyses, and it is the first to employ such methods to evaluate shoreline transformation in the western Pacific. We visit each island, interview local people regarding recent land changes and events, and carry out site investigations and mapping. Each inhabited island is circumambulated on foot, and beach slopes and scarps are measured, sediments examined, human activities and vegetation damage noted, etc. More importantly, the entire coast of each island is mapped using MobileMapper PRO portable units capable of generating GIS shapefiles in the field. Created coverages include the actual shoreline, sandy banks, vegetated areas, coastal engineering, control points, etc. Data collected on the ground is imported into ArcGIS and rectified using remote sensing imagery. It is then compared to all available historical maps, notably US Army Corps of Engineers 1960s topographic charts, which were previously assembled, digitized, and georeferenced for the purposes of this project. Any discrepancies in island outline and land area would have occurred over the past half a century. Due to the vastness of western Pacific region and logistical obstacles to working on remote islands, data are accumulated gradually. Ultimately, this island-by-island approach will allow documentation of historical and regional erosion patterns, contribute to understanding of local and global components of recent coastal changes, and deliver recommendations for environmental management and emergency avoidance on atolls and other

  2. Bikini Atoll ionizing radiation survey - May 1985 - May 1986

    International Nuclear Information System (INIS)

    Shingleton, K.L.; Cate, J.L.; Trent, M.G.; Robison, W.L.

    1988-01-01

    Between 1946 and 1958, the United States conducted 23 nuclear tests at the Bikini Atoll in the Marshall Islands. The single largest detonation was the Bravo test, which resulted in extensive radioactive contamination of a number of islands and prevented the timely resettlement of the native population. Since 1958, many studies have been conducted to assess clean up options and the internal and external radiation doses the Bikinians would likely receive, should they resettle the islands. Although the external dose rates from β and γ radiation have been previously determined by aerial and ground measurement techniques, technical constraints limited the assessment of external β dose rates from the Cs-137 and Sr-90/Y-90 contamination on the islands. Now, because of the recent development of very thin thermoluminescent dosimeters (TLDs), these external β dose rates can be measured

  3. Future Reef Growth Can Mitigate Physical Impacts of Sea-Level Rise on Atoll Islands

    Science.gov (United States)

    Beetham, Edward; Kench, Paul S.; Popinet, Stéphane

    2017-10-01

    We present new detail on how future sea-level rise (SLR) will modify nonlinear wave transformation processes, shoreline wave energy, and wave driven flooding on atoll islands. Frequent and destructive wave inundation is a primary climate-change hazard that may render atoll islands uninhabitable in the near future. However, limited research has examined the physical vulnerability of atoll islands to future SLR and sparse information are available to implement process-based coastal management on coral reef environments. We utilize a field-verified numerical model capable of resolving all nonlinear wave transformation processes to simulate how future SLR will modify wave dissipation and overtopping on Funafuti Atoll, Tuvalu, accounting for static and accretionary reef adjustment morphologies. Results show that future SLR coupled with a static reef morphology will not only increase shoreline wave energy and overtopping but will fundamentally alter the spectral composition of shoreline energy by decreasing the contemporary influence of low-frequency infragravity waves. "Business-as-usual" emissions (RCP 8.5) will result in annual wave overtopping on Funafuti Atoll by 2030, with overtopping at high tide under mean wave conditions occurring from 2090. Comparatively, vertical reef accretion in response to SLR will prevent any significant increase in shoreline wave energy and mitigate wave driven flooding volume by 72%. Our results provide the first quantitative assessment of how effective future reef accretion can be at mitigating SLR-associated flooding on atoll islands and endorse active reef conservation and restoration for future coastal protection.

  4. Baseline Marine Biological Survey ROI-NAMUR Outfall United States Army Kwajalein Atoll, Republic of the Marshall Islands, 1997(NODC Accession 0000630)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Roi-Namur is located at the northernmost tip of Kwajalein Atoll, approximately 64 kilometers north of the U.S. Army Kwajalein Atoll(USAKA) central command post on...

  5. Baseline marine biological survey at Roi-Namur sewage outfall, United States Army Kwajalein Atoll, Republic of the Marshall Islands, 1997 (NODC Accession 0000630)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Roi-Namur is located at the northernmost tip of Kwajalein Atoll, approximately 64 kilometers north of the U.S. Army Kwajalein Atoll (USAKA) central command post on...

  6. Marine biological survey of ROI-NAMUR outfall at the United States Army Kwajalein Atoll, Republic of the Marshall Islands, May 2000 (NODC Accession 0000653)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Roi-Namur is located at the northernmost tip of Kwajalein Atoll, approximately 64 kilometers north of the U.S. Army Kwajalein Atoll (USAKA) central command post on...

  7. Microbial Ecology of Four Coral Atolls in the Northern Line Islands

    Science.gov (United States)

    Smriga, Steven; Edwards, Robert A.; Angly, Florent; Wegley, Linda; Hatay, Mark; Hall, Dana; Brown, Elysa; Haynes, Matthew; Krause, Lutz; Sala, Enric; Sandin, Stuart A.; Thurber, Rebecca Vega; Willis, Bette L.; Azam, Farooq; Knowlton, Nancy; Rohwer, Forest

    2008-01-01

    Microbes are key players in both healthy and degraded coral reefs. A combination of metagenomics, microscopy, culturing, and water chemistry were used to characterize microbial communities on four coral atolls in the Northern Line Islands, central Pacific. Kingman, a small uninhabited atoll which lies most northerly in the chain, had microbial and water chemistry characteristic of an open ocean ecosystem. On this atoll the microbial community was equally divided between autotrophs (mostly Prochlorococcus spp.) and heterotrophs. In contrast, Kiritimati, a large and populated (∼5500 people) atoll, which is most southerly in the chain, had microbial and water chemistry characteristic of a near-shore environment. On Kiritimati, there were 10 times more microbial cells and virus-like particles in the water column and these microbes were dominated by heterotrophs, including a large percentage of potential pathogens. Culturable Vibrios were common only on Kiritimati. The benthic community on Kiritimati had the highest prevalence of coral disease and lowest coral cover. The middle atolls, Palmyra and Tabuaeran, had intermediate densities of microbes and viruses and higher percentages of autotrophic microbes than either Kingman or Kiritimati. The differences in microbial communities across atolls could reflect variation in 1) oceaonographic and/or hydrographic conditions or 2) human impacts associated with land-use and fishing. The fact that historically Kingman and Kiritimati did not differ strongly in their fish or benthic communities (both had large numbers of sharks and high coral cover) suggest an anthropogenic component in the differences in the microbial communities. Kingman is one of the world's most pristine coral reefs, and this dataset should serve as a baseline for future studies of coral reef microbes. Obtaining the microbial data set, from atolls is particularly important given the association of microbes in the ongoing degradation of coral reef ecosystems

  8. Formation of atoll garnets in the UHP eclogites of the Tso Morari Complex, Ladakh, Himalaya

    Science.gov (United States)

    Jonnalagadda, Mallika K.; Karmalkar, Nitin R.; Duraiswami, Raymond A.; Harshe, Shivani; Gain, Sarah; Griffin, William L.

    2017-12-01

    The eclogites of the Tso Morari Complex, Ladakh, NW Himalayas preserve both garnets with spectacular atoll textures, as well as whole porphyroblastic garnets. Whole garnets are euhedral, idiomorphic and enclose inclusions of amphibole, phengite and zoisite within the cores, and omphacite and quartz/coesite towards the rims. Detailed electron microprobe analyses and back-scattered electron images show well-preserved prograde zoning in the whole garnets with an increase in Mg and decrease in Ca and Mn contents from the core to the rim. The atoll garnets commonly consist of euhedral ring over island/peninsular core containing inclusions of phengite, omphacite and rarely amphibole between the core and ring. Compositional profiles across the studied atoll grains show elemental variations with higher concentrations of Ca and Mn with low Mg at the peninsula/island cores; contrary to this low Ca, Mn and high Mg is observed at the outer rings. Temperature estimates yield higher values at the Mg-rich atoll garnet outer rings compared to the atoll cores. Atoll garnet formation was favoured by infiltration of fluid formed due to breakdown of hydrous phases, and/or the release of structurally bounded OH from nominally anhydrous minerals at the onset of exhumation. Infiltration of fluids along pre-existing fracture pathways and along mineral inclusion boundaries triggered breakdown of the original garnet cores and released elements which were subsequently incorporated into the newly-grown garnet rings. This breakdown of garnet cores and inward re-growth at the outer ring produced the atoll structure. Calibrated geo-thermobarometers and mineral equilibria reflect that the Tso Morari eclogites attain peak pressures prior to peak temperatures representing a clockwise path of evolution.

  9. Microbial ecology of four coral atolls in the Northern Line Islands.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Dinsdale

    Full Text Available Microbes are key players in both healthy and degraded coral reefs. A combination of metagenomics, microscopy, culturing, and water chemistry were used to characterize microbial communities on four coral atolls in the Northern Line Islands, central Pacific. Kingman, a small uninhabited atoll which lies most northerly in the chain, had microbial and water chemistry characteristic of an open ocean ecosystem. On this atoll the microbial community was equally divided between autotrophs (mostly Prochlorococcus spp. and heterotrophs. In contrast, Kiritimati, a large and populated ( approximately 5500 people atoll, which is most southerly in the chain, had microbial and water chemistry characteristic of a near-shore environment. On Kiritimati, there were 10 times more microbial cells and virus-like particles in the water column and these microbes were dominated by heterotrophs, including a large percentage of potential pathogens. Culturable Vibrios were common only on Kiritimati. The benthic community on Kiritimati had the highest prevalence of coral disease and lowest coral cover. The middle atolls, Palmyra and Tabuaeran, had intermediate densities of microbes and viruses and higher percentages of autotrophic microbes than either Kingman or Kiritimati. The differences in microbial communities across atolls could reflect variation in 1 oceaonographic and/or hydrographic conditions or 2 human impacts associated with land-use and fishing. The fact that historically Kingman and Kiritimati did not differ strongly in their fish or benthic communities (both had large numbers of sharks and high coral cover suggest an anthropogenic component in the differences in the microbial communities. Kingman is one of the world's most pristine coral reefs, and this dataset should serve as a baseline for future studies of coral reef microbes. Obtaining the microbial data set, from atolls is particularly important given the association of microbes in the ongoing degradation

  10. The radiological situation at the atolls of Mururoa and Fangataufa. Technical report. V. 1. Radionuclide concentrations measured in the terrestrial environment of the atolls

    International Nuclear Information System (INIS)

    1998-08-01

    This report provides technical details of the terrestrial sampling and measurement campaign undertaken as part of the Study of the Radiological Situation at the Atolls of Mururoa, Fangataufa by the Terrestrial Working Group. The primary objective of this group was to evaluate existing French data on the presence of environmental radionuclides on the atolls of Mururoa, Fangataufa and Tureia in French Polynesia. All aspects of the terrestrial environments of Mururoa and Fangataufa Atolls - the sites of atmospheric and underground nuclear tests - were included in the sampling programme. Tureia Atoll - the nearest inhabited island - was also included in the sampling programme, in order to determine whether deposits from atmospheric testing are detectable there. The task required the co-operation of many different parties in order to provide the supporting logistics for the sampling campaign and the expertise for analysing the different radionuclides of interest in the samples collected. Samples were analysed by members of the IAEA's co-ordinated international network of Analytical Laboratories for Measuring Environmental Radioactivity (ALMERA) and the Agency's laboratories, Seibersdorf. Samples were also sent to the French Service Mixte de Surveillance Radiologique et Biologique (SMSRB)

  11. The radiological situation at the atolls of Mururoa and Fangataufa. Technical report. V. 2. Radionuclide concentrations measured in the aquatic environment of the atolls

    International Nuclear Information System (INIS)

    1998-08-01

    A marine monitoring programme was carried out within the framework of the IAEA's project entitled ''Study of the Radiological Situation at Mururoa and Fangataufa Atolls'' with the aim of assessing present radionuclide concentrations in the marine environment of Mururoa and Fangataufa Atolls. The terms of reference of the marine working group (WG2) included a review of the data provided by the French authorities on radionuclide distributions in the littoral and sub-littoral environments at the atolls. Further, using accredited international laboratories, it was decided to carry out sufficient and new independent monitoring work at and around the atolls in order to validate existing French data and, the same time, to provide a representative and high quality data set on current radionuclide concentrations in the marine environment, with particular reference to the requirement of Task Group A for radiological assessment purposes. This work included measurements of the current radionuclide concentrations in the marine environment, and estimation of concentration factors and K d values appropriate for the region. The variations in activity concentrations in the lagoons over the past few years are discussed, and the likely sources of activity implied by these data are identified where possible

  12. Radionuclide concentrations in underground waters of Mururoa and Fangataufa Atolls.

    Science.gov (United States)

    Mulsow, S; Coquery, M; Dovlete, C; Gastaud, J; Ikeuchi, Y; Pham, M K; Povinec, P P

    1999-09-30

    In 1997 an expedition to Mururoa and Fangataufa Atolls was carried out to sample underground waters from cavity-chimneys and carbonate monitoring wells. The aim of this study was to determine the prevailing concentration and distribution status of radionuclides. Elemental analysis of interstitial waters was carried out in the water fraction as well as in particles collected at 11 underground monitoring wells. 238Pu, 239,240Pu, 241Am, 137Cs, 90Sr, 3H, 125Sb, 155Eu and 60Co were analyzed in both fractions by alpha-, beta- and gamma-spectrometry. Measurements showed that at 60% of the sites, pH and Eh seemed to be related to tidal cycles; in contrast HTO was constant during the sampling time. Interstitial waters from carbonates and transition zones shared similar chemical composition that were not different from that of the surrounding seawater. Waters collected from basalt cavities left after nuclear tests, (Aristee and Ceto) have a different chemical signature characterized by a deficiency in Mg, K and SO4 as well as enrichment in Sr, Si, Al and Cl compared to the rest of the stations. Radionuclide concentrations present in both, water and particulate fractions, were significantly higher at Ceto and Aristee than at any other monitoring wells, except for Fuseau and Mitre monitoring wells (Fangataufa) where values similar to Ceto were found (e.g. 239,240Pu: > 20 mBq g-1). Considering that Pu isotopes showed high Kd values compared to non-sorbing radionuclides such as 3H, 90Sr and 137Cs it is very unlikely that migration from cavities to monitoring wells accounts for the concentration of Pu isotopes and Am at Fuseau 30 and Mitre 27. Perhaps the contact of lagoon waters with the well before sealing could be a possible source of the transuranics found at these sites. The 238Pu/239,240Pu ratios measured in the particles were similar to that of the lagoon (0.38), thus supporting this hypothesis. The fact that transuranics were found only in the particle fraction, in the

  13. Shoreline changes in reef islands of the Central Pacific: Takapoto Atoll, Northern Tuamotu, French Polynesia

    Science.gov (United States)

    Duvat, Virginie K. E.; Pillet, Valentin

    2017-04-01

    Atoll reef islands are considered highly vulnerable to the impacts of climate change. While accelerated sea-level rise is expected to destabilize reef islands, ocean warming and acidification are considered as major threats to coral reef growth, which is of primary importance for the persistence of islands and of food supply to islanders. Using multi-date aerial imagery, shoreline and island changes between 1969 and 2013 were assessed on Takapoto Atoll, Northern Tuamotu region, in French Polynesia. Results show that over the 44-year study period, 41% of islands were stable in area while 33% expanded and 26% contracted. Island expansion was the dominant mode of change on the leeward side of the atoll. Tropical Cyclone Orama (category 3, 1983) contributed to shoreline and island change on the windward side of the atoll through the reworking of previous storm deposits and the injection of fresh sediments in the island system (with up to 62% of an island's land area being covered with fresh sediments). Human activities contributed significantly to shoreline and island change throughout the atoll through infrastructure construction, the removal of the indigenous vegetation from a number of islets and sediment mining.

  14. Coastal groundwater exchange on a small Pacific atoll island: Roi Namur, Republic of the Marshall Islands

    Science.gov (United States)

    Oberle, Ferdinand K. J.; Swarzenski, Peter W.; Storlazzi, Curt

    2017-04-01

    Atoll islands, most of which only average 1-2 meters above today's sea level, provide a tremendous natural laboratory in which to study and better understand the intensifying impacts of high rates of sea-level rise on tropical reef-lined islands globally due to their unique geologic structure and limited water supply. Groundwater resources of atolls are typically minimal due to the low elevation and small surface area of the islands and are also subject to recurring droughts, and more frequent, storm-driven seawater overwash events. Although groundwater is the principal means of freshwater storage on atoll islands and is a major factor in determining the overall sustainability of island communities, hydrological data on how an aquifer will response to changes in sea-level rise or storm-driven overwash remain limited. We here present high-resolution time series hydrogeological and geochemical data to determine the role of the atoll's carbonate geology, land use, and atmospheric and oceanographic forcing in driving coastal groundwater exchange on the island of Roi Namur on Kwajalein Atoll in the Republic of the Marshall Islands. This information can provide new estimates on the recovery and resilience of coastal groundwater resources on such islands to expected climate change-driven perturbations.

  15. 3 CFR 8337 - Proclamation 8337 of January 6, 2009. Establishment of the Rose Atoll Marine National Monument

    Science.gov (United States)

    2010-01-01

    ... of the Rose Atoll Marine National Monument 8337 Proclamation 8337 Presidential Documents Proclamations Proclamation 8337 of January 6, 2009 Proc. 8337 Establishment of the Rose Atoll Marine National... 130 nautical miles east-southeast of Pago Pago Harbor, American Samoa, lies Rose Atoll—the easternmost...

  16. 76 FR 10621 - Palmyra Atoll National Wildlife Refuge, U.S. Pacific Island Territory; Nonnative Rat Eradication...

    Science.gov (United States)

    2011-02-25

    ... any of the following methods. For information on viewing or obtaining the documents, see ``Public... species in their natural setting on the Atoll. The Pacific Remote Islands Marine National Monument... eliminate black rats from Palmyra Atoll. Public Availability of the DEIS The DEIS is available for viewing...

  17. Mapping elemental contamination on Palmyra Atoll National Wildlife Refuge

    Science.gov (United States)

    Struckhoff, Matthew A.; Orazio, Carl E.; Tillitt, Donald E.; Shaver, David K.; Papoulias, Diana M.

    2018-01-01

    Palmyra Atoll, once a WWII U.S. Navy air station, is now a U.S. National Wildlife Refuge with nearly 50 km2 of coral reef and 275 ha of emergent lands with forests of Pisonia grandistrees and colonies of several bird species. Due to the known elemental and organic contamination from chemicals associated with aviation, power generation and transmission, waste management, and other air station activities, a screening survey to map elemental concentrations was conducted. A map of 1944 Navy facilities was georeferenced and identifiable features were digitized. These data informed a targeted survey of 25 elements in soils and sediment at locations known or suspected to be contaminated, using a hand-held X-ray fluorescence spectrometer. At dozens of locations, concentrations of elements exceeded established soil and marine sediment thresholds for adverse ecological effects. Results were compiled into a publically available geospatial dataset to inform potential remediation and habitat restoration activities.

  18. Some statistical aspects of the cleanup of Enewetak Atoll

    International Nuclear Information System (INIS)

    Barnes, M.G.; Giacomini, J.J.; Friesen, H.N.

    1979-01-01

    Cleaning up the radionuclide contamination at Enewetak Atoll has involved a number of statistical design problems. Theoretical considerations led to choosing a grid sampling pattern; practical problems sometimes lead to resampling on a finer grid. Other problems associated with using grids have been both physical and statistical. The standard sampling system is an in situ intrinsic gamma detector which measures americium concentration. The cleanup guidelines include plutonium concentration, so additional sampling of soil is required to establish Pu/Am ratios. The soil sampling design included both guidelines for location of the samples and also a special pattern of subsamples making up composite samples. The large variance of the soil, sample results makes comparison between the two types difficult anyway, but this is compounded by vegetation attenuation of the in situ readings, soil disturbance influences, and differences in devegetation methods. The constraints inherent in doing what amounts to a research and development project, on a limited budget of time and money, in a field engineering environment are also considered

  19. Mapping nuclear craters on Enewetak Atoll, Marshall Islands

    Science.gov (United States)

    Hampson, John C., Jr.

    1986-01-01

    In 1984, the U.S. Geological Survey conducted a detailed geologic analysis of two nuclear test craters at Enewetak Atoll, Marshall Islands, on behalf of the Defense Nuclear Agency. A multidisciplinary task force mapped the morphology, surface character, and subsurface structure of two craters, OAK and KOA. The field mapping techniques include echo sounding, sidescan sonar imaging, single-channel and multichannel seismic reflection profiling, a seismic refraction survey, and scuba and submersible operations. All operations had to be navigated precisely and correlatable with subsequent drilling and sampling operations. Mapping with a high degree of precision at scales as large as 1:1500 required corrections that often are not considered in marine mapping. Corrections were applied to the bathymetric data for location of the echo- sounding transducer relative to the navigation transponder on the ship and for transducer depth, speed of sound, and tidal variations. Sidescan sonar, single-channel seismic reflection, and scuba and submersible data were correlated in depth and map position with the bathymetric data to provide a precise, internally consistent data set. The multichannel and refraction surveys were conducted independently but compared well with bathymetry. Examples drawn from processing the bathymetric, sidescan sonar, and single- channel reflection data help illustrate problems and procedures in precision mapping.

  20. Environmental assessment for the resettlement of Eneu Island on Bikini Atoll, Republic of the Marshall Islands

    International Nuclear Information System (INIS)

    Maragos, J.E.; Agegian, Catherine

    1986-01-01

    This environmental assessment evaluates various alternatives to return the Bikini people to their homeland on Bikini Atoll. Eneu Island was spared the heavy nuclear contamination that rendered Bikini Island, the largest and main inhabitable island on the atoll, presently unsuitable for resettlement. The economic, social, technical and environmental consequences of all alternatives were compared, and alternative sites, purposes and scales for resettlement were included in the analysis. This environmental assessment explores these alternatives in detail and concludes that the resettlement of Eneu Island by some of the Bikini people at this time will not result in significant adverse effects to the environment nor will it foreclose any other full scale resettlement option involving the cleanup of Bikini Atoll. In addition, it concludes that the resettlement of Eneu can be accomplished independently from the planned cleanup and resettlement of Bikini Island. Plans and combination of plans involving the early resettlement of Eneu are fully feasible and implementable at this time. (author)

  1. Environmental assessment for the resettlement of Eneu Island on Bikini Atoll, Republic of the Marshall Islands

    Energy Technology Data Exchange (ETDEWEB)

    Maragos, J E [Environmental Resources Section, U.S. Army Corps of Engineers, Pacific Ocean Division, HI (United States); Agegian, Catherine [University of Hawaii, Department of Oceanography, Honolulu, HI (United States)

    1986-07-01

    This environmental assessment evaluates various alternatives to return the Bikini people to their homeland on Bikini Atoll. Eneu Island was spared the heavy nuclear contamination that rendered Bikini Island, the largest and main inhabitable island on the atoll, presently unsuitable for resettlement. The economic, social, technical and environmental consequences of all alternatives were compared, and alternative sites, purposes and scales for resettlement were included in the analysis. This environmental assessment explores these alternatives in detail and concludes that the resettlement of Eneu Island by some of the Bikini people at this time will not result in significant adverse effects to the environment nor will it foreclose any other full scale resettlement option involving the cleanup of Bikini Atoll. In addition, it concludes that the resettlement of Eneu can be accomplished independently from the planned cleanup and resettlement of Bikini Island. Plans and combination of plans involving the early resettlement of Eneu are fully feasible and implementable at this time. (author)

  2. Environmental sampling plan for Kwajalein Atoll Lagoon: 2017 Kwajalein sampling event

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, T. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-07-01

    Since the early 1980s, the U.S DOE Marshall Islands Program at LLNL has provided radiological monitoring of the marine and terrestrial environment at nuclear affected atolls in the northern Marshall Islands. The fundamental aim of these studies was to identify the level and distribution of key residual fallout radionuclide in the environment, improve understanding of prevalent radiation exposure pathways, and develop predictive dose assessments for resettled and resettling atoll population groups. These data and information were essential in terms of guiding the development of effective and environmentally protective remedial measures, and promoting potential actions to improve on food safety and security.

  3. Radionuclide concentrations in fish and invertebrates from Bikini Atoll

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Wong, K.M.; Eagle, R.J.; Jokela, T.A.; Brunk, J.A.

    1988-01-01

    As in other global studies, 137 Cs was found in the highest concentrations in edible flesh of all species of fish and in the lowest concentrations in the bone or liver. The mean concentration of 137 Cs in muscle of reef fish from the southern part of the atoll is comparable to the global-fallout concentration measured in market samples of fish collected from Chicago, IL, USA, in 1982. Strontium-90 is associated generally with non-edible parts of fish, such as bone or viscera. Twenty-five to fifty percent of the total body burden of 60 Co is accumulated in the muscle tissue; the remainder is distributed among the liver, skin, and viscera. The mean concentration of 60 Co in fish has been decreasing at a rate faster than radiological decay alone. Most striking is the range of 207 Bi concentrations among different species of fish collected at the same time and place. Highest concentrations of 207 Bi were consistently detected in the muscle and other tissues of goatfish and some of the pelagic lagoon fish. In other reef fish, such as mullet, surgeonfish, and parrotfish, 207 Bi was usually below detection limits by gamma spectrometry. Over 70% of the whole-body activity of 207 Bi in goatfish is associated with the muscle tissue, whereas less than 5% is found in the muscle of mullet and surgeonfish. Neither 239+240 Pu nor 241 Am is accumulated significantly in the muscle tissue of any species of fish. Apparently, 238 Pu is in a more readily available form for accumulation by fishes than 239+240 Pu. Based on a daily ingestion rate of 200 g of fish flesh, dose rates to individuals through the fish-food ingestion pathway are well below current Federal guidelines. 24 refs., 1 fig., 27 tabs

  4. Zoogeography of the shorefish fauna of Clipperton Atoll

    Science.gov (United States)

    Robertson, D. R.; Allen, G. R.

    1996-06-01

    One hundred and fifteen species of fishes (14 oceanic, plus 101 shore and nearshore species) are known from Clipperton Island, a small, remote coral atoll in the tropical eastern Pacific (TEP). This fish fauna includes only ˜ 14% of the region's shallow-water species, and also is depauperate relative to the fish faunas of other isolated tropical islands. The island's isolation, small size, reduced habitat diversity, and oceanic environment contribute to this paucity of species. Fifty-two species at Clipperton can be identified as TEP; these include 37 widespread species, six species shared only with the Revillagigedo Islands [the nearest (950 km) offshore shoals], and eight endemic to Clipperton. Endemics species apparently have a mix of west and east Pacific origins. Sixty-three species are transpacific; they include three new records (of Naso surgeonfishes) that maybe vagrants recruited > 4,000 km from Oceania. Clipperton is situated at the juncture between the TEP and Oceania. Its fish fauna contains about equal numbers of TEP and transpacific species. This faunal structure reflects the relative influence of surface currents from Oceania and the TEP. Although most of Clipperton's transpacific shorefishes are widespread in eastern Oceania, the Clipperton fauna has specific affinities to the fauna of the Line Islands, which are located within the main eastbound current from Oceania. Clipperton may therefore be a major stepping stone for dispersal between Oceania and the remainder of the TEP. About 50% of the non-oceanic, tropical transpacific fishes occur there, and at least 75 % of those species apparently have resident populations at the island.

  5. Population dynamics of Siderastrea stellata Verrill, 1868 from Rocas Atoll, RN: implications for predicted climate change impacts at the only South Atlantic atoll

    Directory of Open Access Journals (Sweden)

    BARBARA R. PINHEIRO

    Full Text Available ABSTRACT Coral reefs are one of the most vulnerable ecosystems to ocean warming and acidification, and it is important to determine the role of reef building species in this environment in order to obtain insight into their susceptibility to expected impacts of global changes. Aspects of the life history of a coral population, such as reproduction, growth and size-frequency can contribute to the production of models that are used to estimate impacts and potential recovery of the population, acting as a powerful tool for the conservation and management of those ecosystems. Here, we present the first evidence of Siderastrea stellata planulation, its early growth, population size-frequency distribution and growth rate of adult colonies in Rocas Atoll. Our results, together with the environmental protection policies and the absence of anthropogenic pressures, suggest that S. stellata population may have a good potential in the maintenance and recovery in the atoll. However, our results also indicate an impact on corals' recruitment, probably as a consequence of the positive temperature anomaly that occurred in 2010. Thus, despite the pristine status of Rocas Atoll, the preservation of its coral community seems to be threatened by current global changes, such as more frequent thermal stress events.

  6. Population dynamics of Siderastrea stellata Verrill, 1868 from Rocas Atoll, RN: implications for predicted climate change impacts at the only South Atlantic atoll.

    Science.gov (United States)

    Miranda, Andrea L; Cordeiro, Soraia M; Reis, Joice N; Cardoso, Lucas G; Guimarães, Alaíse G

    2017-01-01

    Coral reefs are one of the most vulnerable ecosystems to ocean warming and acidification, and it is important to determine the role of reef building species in this environment in order to obtain insight into their susceptibility to expected impacts of global changes. Aspects of the life history of a coral population, such as reproduction, growth and size-frequency can contribute to the production of models that are used to estimate impacts and potential recovery of the population, acting as a powerful tool for the conservation and management of those ecosystems. Here, we present the first evidence of Siderastrea stellata planulation, its early growth, population size-frequency distribution and growth rate of adult colonies in Rocas Atoll. Our results, together with the environmental protection policies and the absence of anthropogenic pressures, suggest that S. stellata population may have a good potential in the maintenance and recovery in the atoll. However, our results also indicate an impact on corals' recruitment, probably as a consequence of the positive temperature anomaly that occurred in 2010. Thus, despite the pristine status of Rocas Atoll, the preservation of its coral community seems to be threatened by current global changes, such as more frequent thermal stress events.

  7. Modelling detrital coral grain-size and age: Insights from sediment abrasion process of Yongle Atoll of South China Sea

    Science.gov (United States)

    Li, Y.; Zou, X.; Ge, C.; Tan, M.; Wang, C.

    2017-12-01

    Reef islands situated on the rims of atolls are composed almost exclusively of bioclastic materials locally supplied from adjacent coral reefs. Major skeletal component of these islands include coral, coralline algae, mollusks and foraminifera, produced in adjacent reefs. As the island builder, the bioclastic material is the sedimentary products, which also is the point of penetration to decipher the process. The bioclast of coral islands decrease in size with the transportation process. The grain-size provides a proxy record for the abrasion history of the unconsolidated sediment. The 230Th age of coral record the abrasion time. We hereby present a model to calculate the abrasion rate based on the data of 230Th age and grain-size of Yongle Atoll of Xisha Island, South China Sea. The grain size pattern in Yongle Atoll environment have confirm that the coral article diminution behave exponentially. The sediment composition of Yongle Atoll is identified, coral is dominant sediment constituent and the Th230 age is shown to exert an age distribution characteristics of coral detritus. We illustrate this approach by calculate the coral debris age of Xude Atoll, which located near the Yongle Atoll and then by comparing actual measured age and calculated age and to explore the dependence of the model. Observed 230 Th ages are well matched by predicted ages for medium age sediment. A poorer match for young and old sediment may result from some combination of large analytical uncertainties in the detrital ages and inhomogeneous erosion rates within the atoll. Such mismatches emphasize the need for more accurate kinematic models and for sampling strategies that are adapted to atoll-specific geologic and geomorphic conditions. Results presented constitute important new insights into regional sediment abrasion processed and on the evolution of coral atoll islands.

  8. Dispersion of radionuclides potentially released from the Atolls of Mururoa and Fangataufa to neighboring archipelagos

    International Nuclear Information System (INIS)

    Osvath, I.

    1999-01-01

    This paper presents a compartmental model developed to simulate dispersion of radionuclides released to the ocean from the atolls of Mururoa and Fangataufa on a scale of 3000 x 1700 km (150 deg. to 300 deg. S latitude, 130 deg. to 160 deg. W longitude), including the Tuamotu, Cook, Society, Gambier and Austral archipelagos

  9. Monogenea of fishes from the lagoon flats of Palmyra Atoll in the Central Pacific

    Directory of Open Access Journals (Sweden)

    Victor Manuel Vidal-Martinez

    2017-11-01

    Full Text Available A survey of the monogeneans of fishes from the lagoon flats of Palmyra Atoll detected 16 species already reported from the Indo-West Pacific faunal region. A total of 653 individual fish from 44 species were collected from the sand flats bordering the lagoon of the atoll. Eighteen species of fish were infected with monogeneans. The monogenean species recovered were: Benedenia hawaiiensis on Acanthurus xanthopterus, Chaetodon auriga, Chaetodon lunula, Mulloidichthys flavolineatus, Pseudobalistes flavimarginatus and Rhinecanthus aculeatus; Ancyrocephalus ornatus on Arothron hispidus; Euryhaliotrema annulocirrus on Chaetodon auriga and Chaetodon lunula; Euryhaliotrema chrysotaeniae on Lutjanus fulvus; Euryhaliotrema grandis on Chaetodon auriga and Chaetodon lunula; Haliotrema acanthuri on Acanthurus triostegus; Haliotrema aurigae on Chaetodon auriga and Chaetodon lunula; Haliotrema dempsteri on Acanthurus xanthopterus; Haliotrema minutospirale on Mulloidichthys flavolineatus; Haliotrematoides patellacirrus on Lutjanus monostigma; Neohaliotrema bombini on Abudefduf septemfasciatus and Abudefduf sordidus; Acleotrema girellae and Acleotrema parastromatei on Kyphosus cinerascens; Cemocotylella elongata on Caranx ignobilis, Caranx melampygus and Caranx papuensis; Metamicrocotyla macracantha on Crenimugil crenilabris; and Pseudopterinotrema albulae on Albula glossodonta. All these monogenean–host combinations represent new geographical records. The monogenean species composition of the Palmyra Atoll is similar to that of the Hawaiian Islands. However, the number of species recovered was lower compared with other localities within the Indo-West Pacific, perhaps due to the geographical isolation of Palmyra Atoll.

  10. CRED Gridded Bathymetry near Midway Atoll (100-102), Northwestern Hawaiian Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — File 100-102b is a 60-m ASCII grid of depth data collected near Midway Atoll in the Northwestern Hawaiian Islands as of May 2003. This grid has been produced as part...

  11. Culture, hydrology, and other situational controls on atoll freshwater availability (Majuro, Republic of the Marshall Islands)

    Science.gov (United States)

    Shuster, W.

    2016-12-01

    The comparatively uncertain rainfall catch and rising seas in isolated North Pacific atoll communities has presented serious challenges to maintain human communities with freshwater volume. Moreover, the feudal hierarchy, which structures social and economic relationships among local governance and citizens contributes equally to problems and potential solutions. These relationships modulate the availability of critical ecosystem services generated by freshwater, with additional constraints contributed by climate change, rainfall variability (e.g., current El Niño climate pattern), and continuous threat of drought. The major freshwater resources for an atoll are the groundwater freshwater lens, residential and commercial rainwater harvesting, large-scale rainfall catchments (e.g., an airport runway), imported-virtual water, or desalinization subsidies. The significance of each of these resources scale across different atolls according to size, topography, soils, population, infrastructure, and land ownership. The potential integration and coordination of these water resources is largely unrealized due to land ownership, the lack of a contiguous catchment area, uneven and fractured governance. The situational aspects are further characterized by feuding among families and communities (some resource rich, some resource poor), and conflicting land use priorities where agriculture placement and practice can compromise the quality of already limited freshwater resources. This presentation uses the example of Majuro atoll (Republic of the Marshall Islands), field data and other observations, to illustrate sociohydrologic-drivers of freshwater availability, and suggests approaches that may improve on current and ongoing threats to public health and well-being.

  12. 33 CFR 334.1440 - Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. 334.1440 Section 334.1440 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.1440 Pacific Ocean at Kwajalein...

  13. Dongsha Atoll: A potential thermal refuge for reef-building corals in the South China Sea.

    Science.gov (United States)

    Tkachenko, Konstantin S; Soong, Keryea

    2017-06-01

    Dongsha Atoll (also known as the Pratas Islands), the northernmost atoll in the South China Sea, experiences two contrasting physical phenomena: repetitive anomalies of the sea surface temperature exceeding the coral bleaching threshold and regular effects of the world's strongest internal waves resulting in the rhythmic upwelling of cold deep waters at the outer reef slopes of the atoll. This unique combination may result in significant differences in coral species composition and structure between the lagoon and forereef. Surveys conducted in August-September 2016 at 12 study sites in the 2-15 m depth range at Dongsha Atoll revealed a clear spatial separation between 'thermally-susceptible' stony coral genera, including Acropora, Pocillopora and Montipora, which mainly inhabited the forereef, and 'thermally-resistant' genera, including massive Porites, foliaceous Echinopora, Pavona and Turbinaria, which mainly resided in the lagoon. The mean coral cover and species richness on the forereef were respectively 1.8 and 1.4 times higher than those in the lagoon (61.3% and 98 species on the forereef vs. 34.2% and 69 species in the lagoon). Coral mortality rates, expressed as the ratio of dead to live stony corals, showed the same pattern (0.4 in the lagoon vs. 0.009 on the forereef). Furthermore, in a laboratory experiment, 'thermally-susceptible' taxa from the lagoon, (e.g. Pocillopora verrucosa and P. damicornis), exhibited higher resistance to bleaching than did their counterparts from the forereef. The present findings indicate that Dongsha Atoll is a potential thermal refuge for reef-building corals in the northern South China Sea and reveal the development of resilience and resistance to bleaching in coral communities of the lagoon. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Relationships between benthic cover, current strength, herbivory, and a fisheries closure in Glovers Reef Atoll, Belize

    Science.gov (United States)

    McClanahan, T.; Karnauskas, M.

    2011-03-01

    Benthic cover, current strengths, and fish abundance and diversity were examined on 150 lagoonal patch reefs and mapped to determine their distribution, inter-relationships, and relationship to the fisheries closure in Glovers Reef Atoll. Current strength was highest at both the northern and southern ends of the atoll and largely controlled by local wind and weakly by tidal forcing. Benthic functional group distributions varied throughout the atoll and had distinct areas of dominance. In contrast, dominance of coral species was weaker, reflecting the lost cover and zonation of Acropora, Porites, and Montastraea that were reported in the 1970s. Hard and soft corals dominated the windward rim, while the central and leeward lagoon had lower current strengths and sea grass and fleshy green algae were relatively more abundant. Brown erect algae were relatively more common in the north and calcifying green and red algae the southern ends of the atoll. Only Montastraea- Agaricia agaricites distributions were similar to reports from the 1970s with high relative dominance in the southern and northeast atoll. The central-northern zone, which was described as an Acropora zone in the 1970s, was not recognizable, and Porites porites, P. astreoides, Millepora alcicornis, and Favia fragum were the most abundant species during this survey . Hard and soft coral cover abundance declined away from the reef rim and tidal channels and was associated with fast seawater turnover and high surgeonfish abundance. Consequently, the windward rim area has retained the most original and persistent hard-soft coral and surgeonfish community and is considered a priority for future management, if the goal is to protect coral from fishing impacts.

  15. Recommender systems

    OpenAIRE

    Lu L.; Medo M.; Yeung C.H.; Zhang Y.-C.; Zhang Z.-K.; Zhou T.

    2012-01-01

    The ongoing rapid expansion of the Internet greatly increases the necessity of effective recommender systems for filtering the abundant information. Extensive research for recommender systems is conducted by a broad range of communities including social and computer scientists, physicists, and interdisciplinary researchers. Despite substantial theoretical and practical achievements, unification and comparison of different approaches are lacking, which impedes further advances. In this article...

  16. CRED 20m Gridded bathymetry and IKONOS estimated depths of Pearl and Hermes Atoll, Hawaii, USA (Arc ASCII format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of Pearl and Hermes Atoll, Hawaii, USA. Bottom coverage was achieved in depths...

  17. CRED 5 m Gridded bathymetry and IKONOS estimated depths of Pearl and Hermes Atoll, Hawaii, USA (Arc ASCII format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of Pearl and Hermes Atoll, Hawaii, USA. Bottom coverage was achieved in depths...

  18. CRED 20 m Gridded bathymetry and IKONOS estimated depths of Pearl and Hermes Atoll, Hawaii, USA (NetCDF format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of Pearl and Hermes Atoll, Hawaii, USA. Bottom coverage was achieved in depths...

  19. CRED 5 m Gridded bathymetry and IKONOS estimated depths of Pearl and Hermes Atoll, Hawaii, USA (NetCDF format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of Pearl and Hermes Atoll, Hawaii, USA. Bottom coverage was achieved in depths...

  20. Palmyra Atoll, 2006 Sea Surface Temperature and Meteorological Enhanced Mooring - CRED CREWS Near Real Time and Historical Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site Palmyra Atoll, (5.88467, -162.10281 ) ARGOS ID 307-001. Time series data from this mooring provide high resolution sea surface temperature and conductivity, and...

  1. Clipperton Atoll Core 2B Stable Isotope (delta 13C, delta 18O) Data for 1893 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 101 year stable isotope record from P. lobata, core 4B, Clipperton Atoll, eastern Pacific. Sampling at annual and 12/year resolution, files clipperton.4B.iso.txt and...

  2. Clipperton Atoll Core 3C Stable Isotope (delta 13C, delta 18O) Data for 1893 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 101 year stable isotope record from P. lobata, core 4B, Clipperton Atoll, eastern Pacific. Sampling at annual and 12/year resolution, files clipperton.4B.iso.txt and...

  3. Clipperton Atoll Core 4B Stable Isotope (delta 13C, delta 18O) Data for 1893 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 101 year stable isotope record from P. lobata, core 4B, Clipperton Atoll, eastern Pacific. Sampling at annual and 12/year resolution, files clipperton.4B.iso.txt and...

  4. Population characteristics of the mole crab, Hippa adactyla Fabricius, in the intertidal sediment at Kavaratti Atoll, Lakshadweep Islands

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Sreepada, R.A.; Ansari, Z.A.; Parulekar, A.H.

    Some population characteristics of a little known mole crab Hippa adactyla from the sandy intertidal habitat of Kavaratti atoll, Lakshadweep islands, were studied for understanding the resource potentials besides some features of breeding behavior...

  5. The northernmost coral frontier of the Maldives: The coral reefs of Ihavandippolu Atoll under long-term environmental change.

    Science.gov (United States)

    Tkachenko, Konstantin S

    2012-12-01

    Ihavandippolu, the northernmost atoll of the Maldives, experienced severe coral bleaching and mortality in 1998 followed by several bleaching episodes in the last decade. Coral cover in the 11 study sites surveyed in July-December of 2011 in the 3-5 m depth range varied from 1.7 to 51%. Reefs of the islands located in the center of Ihavandippolu lagoon have exhibited a very low coral recovery since 1998 and remain mostly degraded 12 years after the impact. At the same time, some reefs, especially in the inner part of the eastern ring of the atoll, demonstrate a high coral cover (>40%) with a dominance of branching Acropora that is known to be one of the coral genera that is most susceptible to thermal stress. The last severe bleaching event in 2010 resulted in high coral mortality in some sites of the atoll. Differences in coral mortality rates and proportion between "susceptible" and "resistant" taxa in study sites are apparently related to long-term adaptation and local hydrological features that can mitigate thermal impacts. Abundant herbivorous fish observed in the atoll prevent coral overgrowth by macroalgae even on degraded reefs. Despite the frequent influence of temperature anomalies and having less geomorphologic refuges for coral survivals than other larger Maldivian atolls, a major part of observed coral communities in Ihavandippolu Atoll exhibits high resilience and potential for further acclimatization to a changing environment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Recommender systems

    CERN Document Server

    Kembellec, Gérald; Saleh, Imad

    2014-01-01

    Acclaimed by various content platforms (books, music, movies) and auction sites online, recommendation systems are key elements of digital strategies. If development was originally intended for the performance of information systems, the issues are now massively moved on logical optimization of the customer relationship, with the main objective to maximize potential sales. On the transdisciplinary approach, engines and recommender systems brings together contributions linking information science and communications, marketing, sociology, mathematics and computing. It deals with the understan

  7. The atolls of Mururoa and Fangataufa (French Polynesia). The nuclear testings. Radiological aspects; Les atolls de Mururoa et de Fangataufa (Polynesie Francaise). Les experimentations nucleaires. Aspects radiologiques

    Energy Technology Data Exchange (ETDEWEB)

    Martin, G

    2007-07-01

    This report provides a review of the radiological measures implemented during the thirty year period of French nuclear tests in Polynesian atolls of Mururoa and Fangataufa. It presents full details of the practices deployed throughout these tests, including, in particular, aspects concerning radiological protection for the population and the environment. It contains all the scientific results and measurements of radioactivity performed during this period, providing concrete facts that can be used to assess the consequences these tests have had on the personnel involved, the population and the environment. (author)

  8. The radiological situation at the atolls of Mururoa and Fangataufa. Technical report. V. 3. Inventory of radionuclides underground at the atolls

    International Nuclear Information System (INIS)

    1998-08-01

    The objective of Working Group 3 was to independently estimate the underground inventories of radionuclides, at the French nuclear test site on the atolls of Mururoa and Fangataufa, and to estimate the distribution of radionuclides between four major components - lava, rubble, gas and water - that determines the mobility of radionuclides in the geosphere. The group also provided a summary of the critical damage dimensions, such as the cavity radius, fissure zone radius and the height of the chimney. As a lot of dimensional data were provided by the French Liaison Office the focus of this report has been to compare these data with experience gained from other test sites in the world

  9. Reassessment of the potential radiological doses for residents resettling Enewetak Atoll

    International Nuclear Information System (INIS)

    Robison, W.L.; Phillips, W.A.; Mount, M.E.; Clegg, B.R.; Conrado, C.L.

    1980-01-01

    The purpose of this report is to refine the dose predictions, subsequent to the cleanup effort, for alternate living patterns proposed for resettlement of Enewetak Atoll. The most recent data developed from projects at Enewetak and Bikini Atolls for concentration and uptake of Cs, Sr, Pu, and Am were used in conjunction with recent dietary information and current dose models to predict annual dose rates and 30- and 50-y integral doses (dose commitments). The terrestrial food chain in the most significant exposure pathway - it contributes more than 50% of the total dose - and external gamma exposure is the second most significant pathway. Other pathways evaluated are the marine food chain, drinking water, and inhalation

  10. Anthropogenic 236U recorded in annually banded coral skeleton at Majuro atoll, the equatorial Pacific

    International Nuclear Information System (INIS)

    Sakaguchi, Aya; Eto, Asuka; Takahashi, Yoshio; Steier, Peter; Yamazaki, Atsuko; Watanabe, Tsuyoshi; Sasaki, Keiichi; Yamano, Hiroya

    2013-01-01

    Historical 236 U/ 238 U atom ratio and concentration of 236 U were determined by Accelerator Mass Spectrometry (AMS) in skeletons of dated modern coral core sample collected from Majuro atoll, equatorial Pacific, to reconstruct anthropogenic 236 U inputs to the Equatorial Pacific. The maximum hydrogen bomb-pulses of 236 U/ 238 U and 236 U concentration, 2.83x10 -9 and 1.85x10 7 atom/g, in an annually resolved coral core were captured in 1954 (Operation Castle at Bikini and Enewetok atolls). The values were abruptly decreased in a few years, and they have been gradually decreased over time. Our results allow studies of not only the present distribution pattern, but gives access to the temporal evolution of 236 U in surface seawater of North Equatorial Current which is introduced to the Japan Sea and the North West Pacific Ocean as Kuroshio and Tsushima currents over the past decades. (author)

  11. Radiological-dose assessments of atolls in the northern Marshall Islands

    International Nuclear Information System (INIS)

    Robison, W.L.

    1983-04-01

    The Marshall Islands in the Equatorial Pacific, specifically Enewetak and Bikini Atolls, were the site of US nuclear testing from 1946 through 1958. In 1978, the Northern Marshall Islands Radiological Survey was conducted to evaluate the radiological conditions of two islands and ten atolls downwind of the proving grounds. The survey included aerial external gamma measurements and collection of soil, terrestrial, and marine samples for radionuclide analysis to determine the radiological dose from all exposure pathways. The methods and models used to estimate doses to a population in an environment where natural processes have acted on the source-term radionuclides for nearly 30 y, data bases developed for the models, and results of the radiological dose analyses are described

  12. Rickettsial pathogens and arthropod vectors of medical and veterinary significance on Kwajalein Atoll and Wake Island

    Directory of Open Access Journals (Sweden)

    Durden, L.

    2012-05-01

    Full Text Available Modern surveys of ectoparasites and potential vector-borne pathogens in the Republic of the Marshall Islands and Wake Island are poorly documented. We report on field surveys of ectoparasites from 2010 with collections from dogs, cats, and rats. Five ectoparasites were identified: the cat flea Ctenocephalides felis, a sucking louse Hoplopleura pacifica, the mites Laelaps nuttalli and Radfordia ensifera, and the brown dog tickRhipicephalus sanguineus. Ectoparasites were screened for rickettsial pathogens. DNA from Anaplasma platys, a Coxiella symbiont of Rhipicephalus sanguineus, anda Rickettsia sp. were identified by PCR and DNA sequencing from ticks and fleas on Kwajalein Atoll. An unidentified spotted fever group Rickettsia was detected in a pool of Laelaps nuttalli and Hoplopleura pacifica from Wake Island. The records of Hoplopleura pacifica, Laelaps nuttalli, and Radfordia ensifera and the pathogens are new for Kwajalein Atoll and Wake Island.

  13. Symbiodinium spp. associated with scleractinian corals from Dongsha Atoll (Pratas), Taiwan, in the South China Sea.

    Science.gov (United States)

    Keshavmurthy, Shashank; Tang, Kuo-Hsun; Hsu, Chia-Min; Gan, Chai-Hsia; Kuo, Chao-Yang; Soong, Keryea; Chou, Hong-Nong; Chen, Chaolun Allen

    2017-01-01

    Dongsha Atoll (also known as Pratas) in Taiwan is the northernmost atoll in the South China Sea and a designated marine national park since 2007. The marine park's scope of protection covers the bio-resources of its waters in addition to uplands, so it is important to have data logging information and analyses of marine flora and fauna, including their physiology, ecology, and genetics. As part of this effort, we investigated Symbiodinium associations in scleractinian corals from Dongsha Atoll through surveys carried out at two depth ranges (shallow, 1-5 m; and deep, 10-15 m) in 2009 and during a bleaching event in 2010. Symbiodinium composition was assessed using restriction fragment length polymorphism (RFLP) of 28S nuclear large subunit ribosomal DNA (nlsrDNA). Our results showed that the 796 coral samples from seven families and 20 genera collected in 2009 and 132 coral samples from seven families and 12 genera collected in 2010 were associated with Symbiodinium C, D and C+D. Occurrence of clade D in shallow water (24.5%) was higher compared to deep (14.9%). Due to a bleaching event in 2010, up to 80% of coral species associated with Symbiodinium C underwent moderate to severe bleaching. Using the fine resolution technique of denaturing gradient gel electrophoresis (DGGE) of internal transcribed spacer 2 (ITS2) in 175 randomly selected coral samples, from 2009 and 2010, eight Symbiodinium C types and two Symbiodinium D types were detected. This study is the first baseline survey on Symbiodinium associations in the corals of Dongsha Atoll in the South China Sea, and it shows the dominance of Symbiodinium clade C in the population.

  14. Symbiodinium spp. associated with scleractinian corals from Dongsha Atoll (Pratas, Taiwan, in the South China Sea

    Directory of Open Access Journals (Sweden)

    Shashank Keshavmurthy

    2017-01-01

    Full Text Available Dongsha Atoll (also known as Pratas in Taiwan is the northernmost atoll in the South China Sea and a designated marine national park since 2007. The marine park’s scope of protection covers the bio-resources of its waters in addition to uplands, so it is important to have data logging information and analyses of marine flora and fauna, including their physiology, ecology, and genetics. As part of this effort, we investigated Symbiodinium associations in scleractinian corals from Dongsha Atoll through surveys carried out at two depth ranges (shallow, 1–5 m; and deep, 10–15 m in 2009 and during a bleaching event in 2010. Symbiodinium composition was assessed using restriction fragment length polymorphism (RFLP of 28S nuclear large subunit ribosomal DNA (nlsrDNA. Our results showed that the 796 coral samples from seven families and 20 genera collected in 2009 and 132 coral samples from seven families and 12 genera collected in 2010 were associated with Symbiodinium C, D and C+D. Occurrence of clade D in shallow water (24.5% was higher compared to deep (14.9%. Due to a bleaching event in 2010, up to 80% of coral species associated with Symbiodinium C underwent moderate to severe bleaching. Using the fine resolution technique of denaturing gradient gel electrophoresis (DGGE of internal transcribed spacer 2 (ITS2 in 175 randomly selected coral samples, from 2009 and 2010, eight Symbiodinium C types and two Symbiodinium D types were detected. This study is the first baseline survey on Symbiodinium associations in the corals of Dongsha Atoll in the South China Sea, and it shows the dominance of Symbiodinium clade C in the population.

  15. Phytoplankton biomass dynamics and environmental variables around the Rocas Atoll Biological Reserve, South Atlantic

    Directory of Open Access Journals (Sweden)

    Marina Cavalcanti Jales

    2015-12-01

    Full Text Available Abstract The Rocas Atoll Biological Reserve is located in the Atlantic Ocean, at 3º 51' S and 33º 49' W. It lies 143 nautical miles from the City of Natal, Rio Grande do Norte (Brazil. The purpose of this study was to analyze the hydrology, water masses, currents and chlorophyll a content to determine the dynamics of phytoplankton biomass around the Rocas Atoll. Samples were collected in July 2010 in the area around the Atoll, using the Research Vessel Cruzeiro do Sul of the Brazilian Navy. Two transects were established according to the surface currents, one of which at the southeast of the Atoll (SE and the other at norwest (NW. Three collection points were determined on each of these transects. Samples were collected at different depths (surface and DCM - Deep Chlorophyll Maximum and different times (day and night. According to PCA (Principal Component Analysis, the nutrients analyzed, DIN (dissolved inorganic nitrogen, DIP (dissolved inorganic phosphorus and silicate, were inversely correlated with temperature and dissolved oxygen. Most environmental variables showed a significant increase due to the turbulence on the Northwest transect. There was an increase in the concentration of chlorophyll a and nutrients when the temperature and oxygen in the mixed layer was reduced due to the influence of the SACW (South Atlantic Central Water. Despite the increase observed in some variables such as nutrient salts and chlorophyll a, the temperature in the mixed layer attained a mean value of 23.23 ºC due to the predominance of Tropical Water. The increase of the phytoplankton biomass on the NW transect was, therefore, caused by the "island effect" and not by upwelling.

  16. Long-distance dispersal of the coconut palm by migration within the coral atoll ecosystem.

    Science.gov (United States)

    Harries, Hugh C; Clement, Charles R

    2014-03-01

    The location of the original home of the coconut palm, Cocos nucifera, and the extent of its natural dispersal are not known. Proponents of a South American origin must explain why it is not indigenous there and why it shows greatest diversity in southern Asia. Conversely, proponents of an Asian origin must explain why there are no Asian Cocoseae and why the closest botanical relative to Cocos is in South America. Both hypotheses share the common problems of how, when, where and in what directions long-distance dispersal occurred. These difficulties are resolved by accepting that C. nucifera originated and dispersed by populating emerging islands of the coral atoll ecosystem, where establishment conditions impose high selection pressures for survival. When lifted by wave action onto virtually sterile, soilless coralline rocks just above sea level and exposed to the full impact of the sun, seednuts must germinate, root and establish vigorous populations. The cavity within the nut augments the buoyancy provided by the thick husk, which in turn protects the embryo and, by delaying germination, simultaneously extends viability while floating and provides a moisture-retentive rooting medium for the young seedling. These adaptations allow coconuts to disperse widely through the coral atoll ecosystem. The monthly production of fruit and the long floating duration ensure that viable seednuts are always available in the lagoon to replace those destroyed by hurricanes and tsunamis, or to populate newly emerged coral atolls elsewhere. Long-distance dispersal is secondary, because it was the spontaneous, independent migration of coral polyps on a prolonged geological time scale that generated new coral atolls in new areas where the coconuts would be amongst the earliest inhabitants. The coconut palm became an intermittent, itinerant, pioneer endemic there, and also on suitable beaches on volcanic or large islands and continental coastlines.

  17. Marshall Islands Fringing Reef and Atoll Lagoon Observations of the Tohoku Tsunami

    Science.gov (United States)

    Ford, Murray; Becker, Janet M.; Merrifield, Mark A.; Song, Y. Tony

    2014-12-01

    The magnitude 9.0 Tohoku earthquake on 11 March 2011 generated a tsunami which caused significant impacts throughout the Pacific Ocean. A description of the tsunami within the lagoons and on the surrounding fringing reefs of two mid-ocean atoll islands is presented using bottom pressure observations from the Majuro and Kwajalein atolls in the Marshall Islands, supplemented by tide gauge data in the lagoons and by numerical model simulations in the deep ocean. Although the initial wave arrival was not captured by the pressure sensors, subsequent oscillations on the reef face resemble the deep ocean tsunami signal simulated by two numerical models, suggesting that the tsunami amplitudes over the atoll outer reefs are similar to that in deep water. In contrast, tsunami oscillations in the lagoon are more energetic and long lasting than observed on the reefs or modelled in the deep ocean. The tsunami energy in the Majuro lagoon exhibits persistent peaks in the 30 and 60 min period bands that suggest the excitation of closed and open basin normal modes, while energy in the Kwajalein lagoon spans a broader range of frequencies with weaker, multiple peaks than observed at Majuro, which may be associated with the tsunami behavior within the more irregular geometry of the Kwajalein lagoon. The propagation of the tsunami across the reef flats is shown to be tidally dependent, with amplitudes increasing/decreasing shoreward at high/low tide. The impact of the tsunami on the Marshall Islands was reduced due to the coincidence of peak wave amplitudes with low tide; however, the observed wave amplitudes, particularly in the atoll lagoon, would have led to inundation at different tidal phases.

  18. Origin and migration of trace elements in the surface sediments of Majuro Atoll, Marshall Islands.

    Science.gov (United States)

    Ito, Lisa; Omori, Takayuki; Yoneda, Minoru; Yamaguchi, Toru; Kobayashi, Ryuta; Takahashi, Yoshio

    2018-07-01

    The sediments of Majuro Atoll, Marshall Islands, consist of bioclastic materials, including foraminifera and coral debris. The sedimentary depth profiles of elements showed that various elements including zinc (Zn) and copper (Cu) were enriched in the upper layers of the islands of Majuro Atoll. Carbon-14 dating revealed that the sedimentation of the upper layer was completed before 1670 and 542 cal BP in Laura and Calalen, respectively. The enriched elements could be categorized by their origins: (a) terrestrial elements transported as dust (aluminum (Al) and rare earth elements (REEs)); (b) anthropogenic elements (Zn and Cu); and (c) elements supplied by seabirds (phosphorus (P)). From the results of the total amount of Al supplied to sediments for ca. 2000 years, Al in Majuro Atoll was suggested to be airborne origin. The enrichment factors of the elements normalized to Al concentration of continental crust showed that REEs were also transported as dust, while Zn and Cu were mainly of anthropogenic origin. The speciation analysis by X-ray absorption near-edge structure (XANES) showed the presence of Zn-Cu alloys originated from industrial products. It was also revealed that Zn was enriched in the surface due to anthropogenic emission after urbanization on Majuro Atoll and fixed by carbonate and phosphate at the upper layer, which inhibits migration of Zn into the deeper layer and its release to the groundwater and costal water. Hence, the fixation of heavy metals at the surface prevents their exposure to aquatic organisms and residents via fresh groundwater in the island. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. The radiological situation at the atolls of Mururoa and Fangataufa. Proceedings of a conference

    International Nuclear Information System (INIS)

    1998-08-01

    In January 1996, France's programme of experiences nucleaires (nuclear experiments) at the atolls of Mururoa and Fangataufa ceased, and soon after that the French Government requested the International Atomic Energy Agency (IAEA) to carry out a study of the radiological situation at the two atolls. The study of the Radiological Situation at the Atolls of Mururoa and Fangataufa lasted almost two years, giving rise to a number of reports which are being issued by the IAEA. From 30 June to 3 July 1998, the IAEA hosted, in Vienna, an International Conference on the Study, the main purpose being to facilitate discussion of the results of the study by the scientific community and other interested parties. The Conference was presided over by Eduardo Bobadilla Lopez of Chile. These proceedings contain the opening addresses of the Conference, a presentation made by a senior representative of France's Commissariat a l'energie atomique and closing remarks by the President of the Conference, by E. Gail de Planque, Chairman of the International Advisory Committee and by Mohamed ElBaradei, Director General of the IAEA. the also contain edited texts reflecting the discussions which took place during the Conference, mainly after the technical presentations covering the various aspects of the Study. These presentations generally paralleled the Main Report on the Study, to which reference is made in the edited texts

  20. Managing an invasive corallimorph at Palmyra Atoll National Wildlife Refuge, Line Islands, Central Pacific

    Science.gov (United States)

    Work, Thierry M.; Aeby, Greta S.; Neal, Benjamin P.; Price, Nichole N.; Conklin, Eric; Pollock, Amanda

    2018-01-01

    In 2007, a phase shift from corals to corallimorpharians (CM) centered around a shipwreck was documented at Palmyra Atoll, Line Islands. Subsequent surveys revealed CM to be overgrowing the reef benthos, including corals and coralline algae, potentially placing coral ecosystems in the atoll at risk. This prompted the U.S. Fish and Wildlife Service, the lead management agency of the atoll, to remove the shipwreck. Subsequent surveys showed reductions in CM around the ship impact site. We explain patterns of spread of the CM in terms of both life history and local currents and show with a pilot study that pulverized bleach may be an effective tool to eradicate CM on a local scale. If applied strategically, particularly in heavily infested (> 66% cover) areas, active intervention such as this could be an effective management tool to reduce CM impact on localized areas and decrease colonization rate of remaining reefs. This is the first documentation of the response of an invasive cnidarian to shipwreck removal. While this was a singular event in Palmyra, the spatial and temporal patterns of this invasion and the eradications lessons described herein, are useful for anticipating and controlling similar situations elsewhere.

  1. Dosimetry methods and results for the former residents of Bikini Atoll

    International Nuclear Information System (INIS)

    Greenhouse, N.A.

    1979-01-01

    The US Government utilized Bikini and Enewetak Atolls in the northern Marshall Islands of Micronesia for atomspheric tests of nuclear explosives in the 1940's and 1950's. The original inhabitants of these atolls were relocated prior to the tests. During the early 1970's, a small but growing population of Marshallese people reinhabited Bikini. Environmental and personnel radiological monitoring programs were begun in 1974 to ensure that doses and dose commitments received by Bikini residents remained within US Federal Radiation Council guidelines. Dramatic increases in 137 Cs body burdens among the inhabitants between April 1977 and 1978 may have played a significant role in the government decision to move the 140 Bikinians in residence off of the atoll in August 1978. The average 137 Cs body burden for the population was 2.3 μCi in April 1978. Several individuals, however, exceeded the maximum permissible body burden of 3 μCi, and some approached 6 μCi. The resultant total dose commitment was less than 200 mrem for the average resident. The average total dose for the mean residence interval of approx. 4.5 years was about 1 rem. The sources of exposure, the probable cause of the unexpected increase in 137 Cs body burdens, and the methods for calculating radionuclide intake and resultant doses are discussed. Suggestions are offered as to the implications of the most significant exposure pathways for the future inhabitation of Bikini and Enewetak

  2. Coral reef fish assemblages at Clipperton Atoll (Eastern Tropical Pacific and their relationship with coral cover

    Directory of Open Access Journals (Sweden)

    Aurora M. Ricart

    2016-11-01

    Full Text Available Clipperton Atoll, one of the most isolated coral reefs worldwide, is of great scientific interest due to its geomorphology and high levels of endemism. This study explored the reef fish assemblage structure of Clipperton Atoll and its relationship with live coral cover. Nine stations were sampled at three sites and three depths (6, 12 and 20 m around the reef, measuring fish species richness and biomass and hermatypic coral cover (at genus level. We evaluated variation in species richness, biomass and diversity of fish assemblages among sites and depths, as well as the relationship between the entire fish assemblage composition and live coral cover. The results showed that species richness and biomass were similar among sites, but differed across depths, increasing with depth. In contrast, diversity differed among sites but not among depths. Multivariate analyses indicated that fish assemblage composition differed among sites and depths in relation to changes in cover of coral of the genera Pocillopora, Porites, Pavona and Leptoseris, which dominate at different depths. The results showed that fish species richness and diversity were low at Clipperton Atoll and that, in isolated coral reefs with a low habitat heterogeneity and low human disturbance, live coral cover has a significant influence on the spatial variation of the reef fish assemblages. This study highlights the importance of coral habitat structure in shaping coral reef fish assemblages.

  3. The radiological situation at the atolls of Mururoa and Fangataufa. Technical report. V. 6. Doses due to radioactive materials present in the environment or released from the atolls

    Energy Technology Data Exchange (ETDEWEB)

    International Advisory Committee, Task Group A

    1998-08-01

    In the previous volumes of this Report the concentrations of residual radioactivity in the environment of Mururoa and Fangataufa atolls have been described, and assessment made of the releases to the environment in the future. The further step in radiological assessment is the derivation of radiation doses that arise to actually or potentially exposed populations, from these concentrations and releases. These doses are estimated in this report. The existence of a hypothetical population resident on Mururoa is postulated as the group which would be most exposed. Doses to this group are estimated together with doses to maximally exposed residents on nearby South Pacific islands, and further afield. An assessment of the potential environmental impact of the residual contaminant radionuclides from the nuclear weapons testing at Mururoa and Fangataufa requires estimates of the incremental dose rates to a variety of marine organisms inhabiting a number of different ecological niches. These estimated dose rates provide the only secure basis for an assessment of the potential radiation effects in the organisms. The approach adopted for this assessment is that employed in a number of recent studies and adapts the dosimetry models for the particular organisms of interest in the atoll environment Refs, figs, tabs. In six volumes

  4. The radiological situation at the atolls of Mururoa and Fangataufa. Technical report. V. 6. Doses due to radioactive materials present in the environment or released from the atolls

    International Nuclear Information System (INIS)

    1998-08-01

    In the previous volumes of this Report the concentrations of residual radioactivity in the environment of Mururoa and Fangataufa atolls have been described, and assessment made of the releases to the environment in the future. The further step in radiological assessment is the derivation of radiation doses that arise to actually or potentially exposed populations, from these concentrations and releases. These doses are estimated in this report. The existence of a hypothetical population resident on Mururoa is postulated as the group which would be most exposed. Doses to this group are estimated together with doses to maximally exposed residents on nearby South Pacific islands, and further afield. An assessment of the potential environmental impact of the residual contaminant radionuclides from the nuclear weapons testing at Mururoa and Fangataufa requires estimates of the incremental dose rates to a variety of marine organisms inhabiting a number of different ecological niches. These estimated dose rates provide the only secure basis for an assessment of the potential radiation effects in the organisms. The approach adopted for this assessment is that employed in a number of recent studies and adapts the dosimetry models for the particular organisms of interest in the atoll environment

  5. Composition, distribution and risk assessment of organochlorine pesticides in soils from the Midway Atoll, North Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Jing [Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074 (China); Woodward, Lee Ann [U.S. Fish and Wildlife Service, Pacific Reefs NWRC, Honolulu, HI 96850 (United States); Li, Qing X., E-mail: qingl@hawaii.edu [Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Wang, Jun, E-mail: wangjun@wbgcas.cn [Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074 (China); Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

    2013-05-01

    Concentrations of legacy organochlorine pesticides (OCPs), including dichlorodiphenyltrichloroethane (DDT) and its metabolites (e.g., DDE and DDD), and hexachlorocyclohexanes (HCHs) were determined in 111 soil samples from the Midway Atoll. OCPs were found in all samples analyzed, with predominance of α-HCH, p,p′-DDD and p,p′-DDT. The total concentrations ranged from 0 to 127 ng g{sup −1} with a median concentration of 17 ng g{sup −1} for HCHs and 1.4 to 643 ng g{sup −1} with a median concentration of 168 ng g{sup −1} for DDTs. The possible degradation pathways and potential sources of DDTs and HCHs were investigated. The total concentrations of DDTs and HCHs were used to evaluate the cancer risk probabilities in humans via ingestion, dermal contact and inhalation of soil particles. Very low cancer risk was found in all soil samples caused by ΣDDTs and ΣHCHs. - Highlights: • Contamination levels of DDTs and HCHs were studied in the Midway Atoll, North Pacific Ocean. • Potential sources of DDTs and HCHs in soils of the Midway Atoll were investigated. • Possible degradation modes of o,p′-DDT in soils of the Midway Atoll were analyzed. • Cancer risks of DDTs and HCHs in soils of the Midway Atoll were assessed.

  6. Report of the preliminary mission of radiological controls on the island of Mangareva and the atolls of Tureia and Hao (French Polynesia). Investigation performed by the CRIIRAD laboratory on the request of the inquiry Commission on consequences of atmospheric nuclear tests

    International Nuclear Information System (INIS)

    2006-01-01

    After a presentation of the objectives of the mission, and a summary of the undertaken actions on each site, this document gives some general information on radionuclides and on the sampling and analysis method. Then, it discusses the results obtained by radiological analyses and gives recommendations about the current radiological situation of the studied island and atolls. It shows that official assessment of radiation doses undergone by the French Polynesia population during the period atmospheric nuclear tests must be revised. It outlines the need of new exhaustive investigations on health consequences of these past exposures to ionizing radiation. Recommendations are formulated

  7. Radionuclide concentrations and dose assessment of cistern water and groundwater at the Marshall Islands

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Eagle, R.J.; Wong, K.M.; Jokela, T.A.; Robison, W.L.

    1981-01-01

    A radiological survey was conducted from September through November of 1978 to determine the concentrations of radionuclides in the terrestrial and marine environments of 11 atolls and 2 islands in the Northern Marshall Islands. More than 70 cistern and groundwater samples were collected at the atolls; the volume of each sample was between 55 and 100 l. The concentration of 90 Sr in cistern water at most atolls is that expected from world-wide fallout in wet deposition. Except for Bikini and Rongelap, 137 Cs concentrations in cistern water are in agreement with the average predicted concentrations from wet deposition. The 239+240 Pu concentrations are everywhere less than the predicted fallout concentrations except at Rongelap, Ailinginae, and Bikini where the measured and predicted concentrations are in general agreement. During the period sampled, most groundwater concentrations of 90 Sr and 137 Cs were everywhere higher than the concentrations in cistern water. Concentrations of the transurancies in filtered groundwater solution were everywhere comparable to or less than the concentrations in cistern water. It is concluded that the concentrations of radionuclides detected during any single period may not necessarily reflect the long-term average concentrations or the concentrations that might be observed if a lined well were extended above the surface. In any case, at all atolls the 90 Sr and 137 Cs concentrations in groundwater are below the concentration guidelines for drinking water recommended by the Environmental Protection Agency. The maximum annual dose rates and the 30- and 50-y integral doses are calculated for the intake of both cistern water and groundwater for each of the atolls

  8. The radiological situation at the atolls of Mururoa and Fangataufa. Technical report. V. 4. Releases to the biosphere of radionuclides from underground nuclear weapon tests at the atolls

    International Nuclear Information System (INIS)

    1998-08-01

    This report is Volume 4 in the series of 6 volumes of the Technical Report on the radiological situation at the atolls of Mururoa and the Fangataufa. It is the second of the three volumes dealing with the evaluation of the long term radiological situation as a consequence of radionuclide migration from underground sources, which is the responsibility of Task Group B. This volume is based on the activities of Working Group 4 and uses, as its primary input on radionuclide inventories the report of Working Group 3, which is Vol. 3 in this series of Technical Report. Nuclear testing in the atmosphere, outer space and under open ocean was prohibited by the Limited Test Ban Treaty of 5 August 1963 and signed by UK, USA and USSR. France ceased atmospheric testing in September 1974. Isolation from the biosphere in geological formations, or containment in geological formations, became the preferred alternative. The explosion of 137 underground nuclear devices in Mururoa and Fangataufa over the testing period 1975-1996, together with 10 safety trials and the burial of radioactively contaminated material gathered from the atoll surfaces, has resulted in a substantial accumulation of radionuclides in the rock beneath the two atolls. Assessment of the rate at which these radionuclides move from the cavities to the environment accessible to humans, or biosphere and the total radionuclide release to the biosphere over time is the central effort of this Study. The rock mass within which the radionuclides are initially deposited, and which serves to contain or delay release of the radionuclides, will be referred to as the geosphere to distinguish it from the biosphere, where the radionuclides would be accessible either directly or through the food chain to the living environment. This assessment of geosphere transport has been divided into the following four interrelated tasks: (a) Geological Pathways; (b) Hydrological Modelling; (c) Solution Source Term; and (d) Geosphere

  9. International recommendations

    International Nuclear Information System (INIS)

    Lindell, Bo

    1986-01-01

    Full text: This short presentation will indicate the general radiation protection background to protective measures against foodstuffs contaminated with radioactive substances. A number of international organizations are involved in various aspects of radiation protection, for example, the International Atomic Energy Agency (IAEA), the United Nations Food and Agriculture Organization (FAO), the United Nations Environment Programme (UNEP), and the World Health Organization (WHO). Two international organizations, however, provide the basic background. These are the International Commission on Radiological Protection (ICRP) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). UNSCEAR provides the scientific information on radiation levels and effects. It consists of 21 member countries, with truly international coverage. It issues reports to the UN General Assembly, including comprehensive scientific annexes. Its latest comprehensive report was issued in 1982, the next is expected to be published in 1988. That report will include an assessment of the radiological consequences of the Chernobyl accident. The ICRP is a non-governmental organization. It has issued recommendations on radiation protection since 1928. The postulated biological basis for radiation protection recommendations involves two types of biological effects. The so-called non-stochastic effects, mainly due to cell death, appear only when the radiation doses exceed a certain threshold value. These effects, therefore, can only appear after high accidental exposures. After the Chernobyl accident, they only affected about 200 individuals involved in fire extinction and rescue work at the damaged nuclear power plant. Stochastic effects, with some simplification, may be seen as the result of initial changes in the genetic code of some surviving cells. If these cells are germ cells, this may lead to hereditary harm. If they are somatic cells, the result could be cancer

  10. Effect of climate and environmental changes on plankton biodiversity and bigeochemical cycles of the Dongsha (Pratas) Atoll, South China Sea

    Science.gov (United States)

    Lo, Wen-tseng; Hsu, Pei-Kai; Hunag, Jia-Jang; Wang, Yu-Huai

    2013-04-01

    Dongsha (Pratas) Atoll, the so called "Pearl Crown of South China Sea", is a well-developed atoll with a total area of 80000 hectares. It possesses various ecosystems and has very high biodiversity, but it is very sensitive to climate change and physical processes. According to our investigation within the shallow semi-enclosed atoll in April, July, and October, 2011 (i.e., spring, summer, and autumn, respectively), we found that plankton assemblages and hydrographical conditions exhibited clear seasonal and spatial variations. Colder and higher salinity water was observed in April, while warmer water in July and lower salinity water in October, respectively. Nutrient concentration within the atoll was similar to that of the oligotrophic South China Sea waters and seemed to be in nitrogen-limit situation, while the distribution pattern of DOC and POC was mainly attributed to Chla and imported detritus matters. Carbon deposition flux also showed significant seasonal changes, but POC/PN value was near Redfield ratio, implying mostly due to biogenic factors; however it could still be classified as a typical coral ecosystem, since CaCO3 sinking flux generally was 30 times higher than that of organic matter. Plankton biodiversity was quite high in the atoll, and preformed apparent seasonal succession; in total, 82 phytoplankton species and 67 copepod species were recorded; furthermore, crab zoea (17.3% of the total zooplankton by number), fish eggs (12.5%), and shrimp larvae (4.2%), were relatively abundant in zooplankton community, revealed that atoll might be a good hatching ground. We deduced that the seasonal patterns of chemical and biological variables were mainly influenced by monsoons and precipitation, while small scales of temporal and spatial variations could be ascribed to internal wave and tide in this study area.

  11. Avian disease assessment in seabirds and non-native passerines birds at Midway Atoll NWR

    Science.gov (United States)

    LaPointe, Dennis A.; Atkinson, Carter T.; Klavitter, John L.

    2013-01-01

    Midway Atoll in the Northwestern Hawaiian Islands supports the largest breeding colony of Laysan albatross (Phoebastria immutabilis) in the world and is a proposed site for the translocation of endangered Northwestern Hawaiian Island passerine birds such as the Nihoa finch (Telespiza ultima), Nihoa millerbird (Acrocephalus familiaris kingi), or Laysan finch (Telespiza cantans). On the main Hawaiian Islands, introduced mosquito-borne avian malaria (Plasmodium relictum) and avian pox (Avipoxvirus) have contributed to the extinction and decline of native Hawaiian avifauna. The mosquito vector (Culex quinquefasciatus) is present on Sand Island, Midway Atoll, where epizootics of Avipoxvirus have been reported among nestling Laysan albatross, black-footed albatross (Phoebastria nigripes), and red-tailed tropicbirds (Phaethon rubricauda) since 1963. Two introduced passerines, the common canary (Serinus canaria) and the common myna (Acridotheres tristis), are also present on Sand Island and may serve as reservoirs of mosquito-borne pathogens. Assessing disease prevalence and transmission potential at Midway Atoll National Wildlife Refuge (NWR) is a critical first step to translocation of Nihoa endemic passerines. In May 2010 and April 2012 we surveyed Midway Atoll NWR for mosquitoes and evidence of mosquito-borne disease. Although we did not observe active pox infections on albatross nestlings in May 2010, active infections were prevalent on albatross nestlings in April 2012. Presumptive diagnosis of Avipoxvirus was confirmed by PCR amplification of the Avipoxvirus 4b core protein gene from lesions collected from 10 albatross nestlings. Products were sequenced and compared to 4b core protein sequences from 28 Avipoxvirus isolates from the Hawaiian Islands and other parts of the world. Sequences from all Midway isolates were identical and formed a clade with other Avipoxvirus isolates from seabirds that was distinct from other Avipoxvirus isolates from the Hawaiian Islands

  12. Coexistence of low coral cover and high fish biomass at Farquhar Atoll, Seychelles.

    Science.gov (United States)

    Friedlander, Alan M; Obura, David; Aumeeruddy, Riaz; Ballesteros, Enric; Church, Julie; Cebrian, Emma; Sala, Enric

    2014-01-01

    We report a reef ecosystem where corals may have lost their role as major reef engineering species but fish biomass and assemblage structure is comparable to unfished reefs elsewhere around the world. This scenario is based on an extensive assessment of the coral reefs of Farquhar Atoll, the most southern of the Seychelles Islands. Coral cover and overall benthic community condition at Farquhar was poor, likely due to a combination of limited habitat, localized upwelling, past coral bleaching, and cyclones. Farquhar Atoll harbors a relatively intact reef fish assemblage with very large biomass (3.2 t ha(-1)) reflecting natural ecological processes that are not influenced by fishing or other local anthropogenic factors. The most striking feature of the reef fish assemblage is the dominance by large groupers, snappers, and jacks with large (>1 m) potato cod (Epinephelus tukula) and marbled grouper (E. polyphekadion), commonly observed at many locations. Napoleon wrasse (Cheilinus undulatus) and bumphead parrotfish (Bolbometopon muricatum) are listed as endangered and vulnerable, respectively, but were frequently encountered at Farquhar. The high abundance and large sizes of parrotfishes at Farquhar also appears to regulate macroalgal abundance and enhance the dominance of crustose corallines, which are a necessary condition for maintenance of healthy reef communities. Overall fish biomass and biomass of large predators at Farquhar are substantially higher than other areas within the Seychelles, and are some of the highest recorded in the Indian Ocean. Remote islands like Farquhar Atoll with low human populations and limited fishing pressure offer ideal opportunities for understanding whether reefs can be resilient from global threats if local threats are minimized.

  13. Coexistence of low coral cover and high fish biomass at Farquhar Atoll, Seychelles.

    Directory of Open Access Journals (Sweden)

    Alan M Friedlander

    Full Text Available We report a reef ecosystem where corals may have lost their role as major reef engineering species but fish biomass and assemblage structure is comparable to unfished reefs elsewhere around the world. This scenario is based on an extensive assessment of the coral reefs of Farquhar Atoll, the most southern of the Seychelles Islands. Coral cover and overall benthic community condition at Farquhar was poor, likely due to a combination of limited habitat, localized upwelling, past coral bleaching, and cyclones. Farquhar Atoll harbors a relatively intact reef fish assemblage with very large biomass (3.2 t ha(-1 reflecting natural ecological processes that are not influenced by fishing or other local anthropogenic factors. The most striking feature of the reef fish assemblage is the dominance by large groupers, snappers, and jacks with large (>1 m potato cod (Epinephelus tukula and marbled grouper (E. polyphekadion, commonly observed at many locations. Napoleon wrasse (Cheilinus undulatus and bumphead parrotfish (Bolbometopon muricatum are listed as endangered and vulnerable, respectively, but were frequently encountered at Farquhar. The high abundance and large sizes of parrotfishes at Farquhar also appears to regulate macroalgal abundance and enhance the dominance of crustose corallines, which are a necessary condition for maintenance of healthy reef communities. Overall fish biomass and biomass of large predators at Farquhar are substantially higher than other areas within the Seychelles, and are some of the highest recorded in the Indian Ocean. Remote islands like Farquhar Atoll with low human populations and limited fishing pressure offer ideal opportunities for understanding whether reefs can be resilient from global threats if local threats are minimized.

  14. Ground-water resources of the Laura area, Majuro Atoll, Marshall Islands

    Science.gov (United States)

    Hamlin, S.N.; Anthony, S.S.

    1987-01-01

    The water system that supplies the heavily populated Dalap-Uliga-Darrit (DUD) area of Majuro atoll, Marshall Island, relies almost entirely upon airstrip catchment of rain water. Droughts cause severe water supply problems and water rationing is required, even during periods of normal rainfall. The Laura area contains a substantial lens of fresh groundwater that could be developed for export to the DUD area 30 mi to the east. Study of the groundwater resource at Laura involved a survey of existing wells, installation of monitoring wells and test holes, compilation of continuous records of rainfall and water level fluctuations, and collection of water quality data. Test hole data permitted the definition of three geohydrologic units which correlate well with similar units in Bikini and Enewetak atolls. The units consist of two layers of unconsolidated reef and lagoon sediments resting on a dense, highly permeable limestone. The potable water zone, or freshwater nucleus, of the lens is contained mostly within the unconsolidated layers, which are much less permeable than the basal limestone. Recharge to the Laura freshwater lens is estimated to be 1.8 mil gal/day, based on an average annual rainfall of 140 in. Sustainable yield is estimated to be about 400,000 gal/day. Shallow skimming wells or infiltration galleries similar to those used on Kwajalein atoll would be appropriate to develop the freshwater lens. The impact of development on the lens can be determined by monitoring the salinity in developed water and in a network of monitor wells. (Author 's abstract)

  15. Drivers of shoreline change in atoll reef islands of the Tuamotu Archipelago, French Polynesia

    Science.gov (United States)

    Duvat, Virginie K. E.; Salvat, Bernard; Salmon, Camille

    2017-11-01

    This paper increases by around 30% the sample of atoll reef islands studied from a shoreline change perspective, and covers an under-studied geographical area, i.e. the French Tuamotu Archipelago. It brings new irrefutable evidences on the persistence of reef islands over the last decades, as 77% of the 111 study islands exhibited areal stability while 15% and 8% showed expansion and contraction, respectively. This paper also addresses a key research gap by interpreting the major local drivers controlling recent shoreline and island change, i.e. tropical cyclones and seasonal swells, sediment supply by coral reefs and human activities. The 1983 tropical cyclones had contrasting impacts, depending on the shoreline indicator considered. While they generally caused a marked retreat of the stability line, the base of the beach advanced at some locations, as a result of either sediment reworking or fresh sediment inputs. The post-cyclone fair weather period was characterised by reversed trends indicating island morphological readjustment. Cyclonic waves contributed to island upwards growth, which reached up to 1 m in places, through the transfer of sediments up onto the island surface. However, the steep outer slopes of atolls limited sediment transfers to the reef flat and island system. We found that 57% of the study islands are disturbed by human activities, including 'rural' and uninhabited islands. Twenty-six percent of these islands have lost the capacity to respond to ocean-climate related pressures, including the 'capital' islands concentrating atolls' population, infrastructures and economic activities, which is preoccupying under climate change.

  16. Radiological and chemical studies of the ground water at Enewetak Atoll. 1. Sampling, field measurements, and analytical methods

    International Nuclear Information System (INIS)

    Marsh, K.V.; Wong, K.M.; Holladay, G.; Noshkin, V.E.; Buddemeier, R.

    1975-01-01

    A research program to study the ground water on several of the islets in the Enewetak Atoll is being conducted jointly by Lawrence Livermore Laboratory and the University of Hawaii under the sponsorship of ERDA Division of Biology and Environmental Research. The purpose is to provide data characterizing the ground water for possible use by returning Marshallese and to investigate the hydrology and recycling of radionuclides in an atoll environment. This first of a series of reports describes the sampling locations, field operations, and methods of analysis

  17. Pisces, Anguilliformes, Moringuidae, Moringua edwardsi (Jordan and Bollman, 1889: First record in Atol das Rocas, northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Paiva, C. C.

    2010-01-01

    Full Text Available Moringua edwardsi is recorded for the first time at Atol das Rocas, northeastern Brazil. Previous records of thespecies were located in the western Atlantic Ocean, from Florida to southeastern Brazil, but with many gaps between theseregions. A single specimen was collected in Atol das Rocas in July 2007 and it is deposited in the Dias da Rocha IchthyologicalCollection. The new record of M. edwardsi fills a geographic distribution gap of this species and complements the inventoryof fish species inhabiting one of the most unique marine protected areas in the world.

  18. Relationship between elemental distribution in soil and human impact in Majuro Atoll

    Science.gov (United States)

    Ito, L.; Takahashi, Y.; Yoneda, M.; Omori, T.; Yamazaki, K.; Yoshida, H.; Tamenori, Y.; Suga, H.; Yamaguchi, T.

    2015-12-01

    Majuro Atoll is one of islands of the Marshall Islands, located in the central Pacific Ocean. Reef-building corals and biological remains such as foraminifera have formed the islands under the influence of sea-level changes in the Holocene. Since the altitude of the general coral reef island tends to be very low, it is believed that the islands are vulnerable to natural disasters and climate change. However, people have lived in the Majuro Atoll in Marshall Islands for more than 2000 years. Reef islands in the same atoll are often considered to have same tendencies in the developing process; however, (i) there are possibilities that each geography produces different condition in habitat and (ii) human activities have changed the original nature in the island. In this study, we focus on the changes of physico-chemical conditions of soil depending on the depth according to time series variation in three islands in Majuro Atoll. Dating of each depth was conducted by radiocarbon (14C) measurement for foraminifera using accelerator mass spectrometry (AMS) and Bayesian age-depth Models. X-ray fluorescence (XRF) and ICP-MS analyses were employed to measure major and trace elements at different depth, respectively. Among them, phosphorus (P) is considered to play an important role in soil development; therefore X-ray absorption fine structure (XAFS) analysis was also conducted to examine the chemical form of P. Scanning electron microscope (SEM) was used to examine the elemental distribution in the soil particles, while X-ray computed tomography (CT) was used to calculate the rate of porosity of foraminifera at each depth. Concentrations of Fe, Mn, and P decrease with depth and vice versa for Mg. As a result of the μ-XAFS analysis, P in the soil exists as organic phosphorus and apatite. Phosphorous detected from the upper layer was found to distribute heterogeneously in the particles, which was observed as punctate pattern by the SEM observation. The ICP-MS results showed

  19. Redistribution of fallout radionuclides in Enewetak Atoll lagoon sediments by callianassid bioturbation

    Energy Technology Data Exchange (ETDEWEB)

    McMurtry, G.M.; Schneider, R.C. (Hawaii Univ., Honolulu (USA). Hawaii Inst. of Geophysics); Colin, P.L. (Hawaii Inst. of Marine Biology, Honolulu (USA)); Buddemeier, R.W. (California Univ., Livermore (USA). Lawrence Livermore Lab.); Suchanek, T.H. (Fairleigh Dickinson Univ., St. Croix, Virgin Islands (USA). West Indies Lab.)

    1985-02-21

    The lagoon sediments of Enewetak Atoll in the Marshall Islands contain a large selection of fallout radionuclides as a result of 43 nuclear weapon tests conducted there between 1948 and 1958. The authors report elevated fallout radionuclide concentrations buried more deeply in the lagoon sediments and evidence of burrowing into the sediment by several species of callianassid ghost shrimp (Crustacea: Thalassinidea) which has displaced highly radioactive sediment. The burrowing activities of callianassids, which are ubiquitous on the lagoon floor, facilitate radionuclide redistribution and complicate the fallout radionuclide inventory of the lagoon.

  20. The atolls of Mururoa and Fangataufa (French Polynesia). The nuclear testings. Radiological aspects

    International Nuclear Information System (INIS)

    Martin, G.

    2007-01-01

    This report provides a review of the radiological measures implemented during the thirty year period of French nuclear tests in Polynesian atolls of Mururoa and Fangataufa. It presents full details of the practices deployed throughout these tests, including, in particular, aspects concerning radiological protection for the population and the environment. It contains all the scientific results and measurements of radioactivity performed during this period, providing concrete facts that can be used to assess the consequences these tests have had on the personnel involved, the population and the environment. (author)

  1. Behavior of plutonium isotopes in the marine environment of Enewetak atoll

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Robison, W.L.; Eagle, R.J.

    1998-01-01

    There continue to be reports in the literature that suggest a difference in the behavior of 239+240 Pu and 238 Pu in some aquatic environments. Plutonium isotopes have been measured in marine samples collected over 3 decades form Enewetak atoll, one of the sites in the Marshall Islands used by the United States between 1946 and 1958 to test nuclear devices. The plutonium isotopes originated from a variety of complex sources and could possibly coexist in this environment as different physical-chemical species. However results indicate little difference in the mobility and biological availability of 239+240 Pu and 238 Pu. (author)

  2. Redistribution of fallout radionuclides in Enewetak Atoll lagoon sediments by callianassid bioturbation

    International Nuclear Information System (INIS)

    McMurtry, G.M.; Schneider, R.C.; Buddemeier, R.W.; Suchanek, T.H.

    1985-01-01

    The lagoon sediments of Enewetak Atoll in the Marshall Islands contain a large selection of fallout radionuclides as a result of 43 nuclear weapon tests conducted there between 1948 and 1958. The authors report elevated fallout radionuclide concentrations buried more deeply in the lagoon sediments and evidence of burrowing into the sediment by several species of callianassid ghost shrimp (Crustacea: Thalassinidea) which has displaced highly radioactive sediment. The burrowing activities of callianassids, which are ubiquitous on the lagoon floor, facilitate radionuclide redistribution and complicate the fallout radionuclide inventory of the lagoon. (author)

  3. Radiochemical analysis of radio-nuclides in sea water collected near Bikini Atoll

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Y; Sugiura, Y

    1955-01-01

    A radiochemical analysis of sea water containing fission materials collected near Bikini Atoll in June, 1954, was performed. The sea water was boiled with hydrochloric acid, iron and lanthanum salts each 5 mg as Fe and La were added to it. They were precipitated as hydroxide, which was dissolved in hydrochloric acid and ferric chloride was extracted with ethyl ether. The remaining solution was evaporated to dryness and the residue was dissolved in hydrochloric acid. Using the latter solution the group separation was done with cation exchanger resins.

  4. Uncharted waters: Bivalves of midway atoll and integrating mathematics into biology education

    Science.gov (United States)

    McCully, Kristin M.

    To protect and conserve the Earth's biodiversity and ecosystem services, it is important not only to understand and conserve species and ecosystems, but also to instill an understanding and appreciation for biodiversity and ecosystem services in the next generations of both scientists and citizens. Thus, this dissertation combines research into the ecology and identity of large bivalves at Midway Atoll in the Northwestern Hawaiian Islands (NWHI) with research on pedagogical strategies for integrating mathematics into undergraduate biology education. The NWHI is one of the few remaining large, mainly intact, predator-dominated coral reef ecosystems and one of the world's largest marine protected areas. Previous bivalve studies focused on the black-lipped pearl oyster, Pinctada margaritifera, which was heavily harvested in the late 1920s, has not recovered, and is now a candidate species for restoration. First, I combined remote sensing, geographic information systems, SCUBA, and mathematical modeling to quantify the abundance, spatial distributions, and filtration capacity of large epifaunal bivalves at Midway Atoll. These bivalves are most abundant on the forereef outside the atoll, but densities are much lower than reported on other reefs, and Midway's bivalves are unlikely to affect plankton abundance and productivity inside the lagoon. Second, I used molecular techniques and phylogenetic reconstructions to identify pearl oysters (Pinctada) from Midway Atoll as P. maculata , a species not previously reported in Hawaii. As a small morphologically cryptic species, P. maculata may be a native species that has not been collected previously, a native species that has been identified incorrectly as the morphologically similar P. radiata, or it may be a recent introduction or natural range extension from the western Pacific. Finally, I review science education literature integrating mathematics into undergraduate biology curricula, and then present and evaluate a

  5. Projections of extreme water level events for atolls in the western Tropical Pacific

    Science.gov (United States)

    Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

    2014-12-01

    Conditions that lead to extreme water levels and coastal flooding are examined for atolls in the Republic of the Marshall Islands based on a recent field study of wave transformations over fringing reefs, tide gauge observations, and wave model hindcasts. Wave-driven water level extremes pose the largest threat to atoll shorelines, with coastal levels scaling as approximately one-third of the incident breaking wave height. The wave-driven coastal water level is partitioned into a mean setup, low frequency oscillations associated with cross-reef quasi-standing modes, and wind waves that reach the shore after undergoing high dissipation due to breaking and bottom friction. All three components depend on the water level over the reef; however, the sum of the components is independent of water level due to cancelling effects. Wave hindcasts suggest that wave-driven water level extremes capable of coastal flooding are infrequent events that require a peak wave event to coincide with mid- to high-tide conditions. Interannual and decadal variations in sea level do not change the frequency of these events appreciably. Future sea-level rise scenarios significantly increase the flooding threat associated with wave events, with a nearly exponential increase in flooding days per year as sea level exceeds 0.3 to 1.0 m above current levels.

  6. Comparison of gamma-ray exposure rate measurements at Bikini Atoll

    International Nuclear Information System (INIS)

    Gudiksen, P.H.; Crites, T.R.

    1975-01-01

    A radiological survey of Bikini and Eneu Islands of the Bikini Atoll was conducted during June 1975 to assess the potential radiation doses that may be received by the returning Bikinians. Bikini Atoll was one of the U.S. nuclear weapons testing sites in the Pacific. An integral part of the survey included measurements of the gamma-ray exposure rates at 1 m above the ground with portable NaI instruments at nearly 2700 locations on the two islands. For comparison purposes, similar measurements were made with a pressurized ion chamber at approximately 200 locations, and with LiF and CaF 2 :Dy thermoluminescent dosimeters (TLDs) at 80 locations. The results indicate that the NaI scintillators overresponded because of their nonlinear energy characteristics. The responses of the LiF dosimeters and the pressurized ion chamber agreed to within 13 percent. Attenuation studies with LiF TLDs indicated that roughly 25 percent of the total free air exposure rate at 1 m was due to beta radiation

  7. Contraction of the southeast Polynesian interaction sphere and resource depression on Temoe Atoll

    International Nuclear Information System (INIS)

    Weisler, M.I.

    2004-01-01

    The southeast Polynesian interaction sphere, involving most frequently islands in Mangareva and the Pitcairn group, was active for at least five centuries beginning about AD 1000. By western contact in the early seventeenth century, all islands in the Pitcairn group were abandoned, signalling a contraction of the sphere. Systematic survey and excavations were conducted on Temoe Atoll, the next closest island to the main Mangareva group, to determine the spatial and temporal boundaries of that contraction. The excavations in five late prehistoric habitation sites are described, and provide the first subsistence remains from the atoll. These consist of 21,590 bones of fish, bird, turtle, Pacific rat and human as well as 25 kg of shell midden, mostly Turbo gastropods. Reconstructed weights of parrotfish (Scaridae), by far the most common fish taxon, illustrate a decline in size during late prehistory, pointing to exploitation depression. The x-ray fluorescence analysis of volcanic artefacts documents ties with the main Mangarewa group, suggesting that the reduced interaction sphere lasted until the early nineteenth century when Temoe was finally abandoned. (author). 34 refs., 10 figs., 6 tabs

  8. Impacts of category 5 tropical cyclone Fantala (April 2016) on Farquhar Atoll, Seychelles Islands, Indian Ocean

    Science.gov (United States)

    Duvat, Virginie K. E.; Volto, Natacha; Salmon, Camille

    2017-12-01

    This paper provides new insights on the impacts of a category 5 tropical cyclone on Indian Ocean atoll reef islands. Using multi-date aerial imagery and field observations, the contribution of tropical cyclone Fantala to shoreline and island change, and to sediment production and transport, was assessed on Farquhar Atoll, Seychelles Islands. Results show that the two largest islands (> 3 km2) only suffered limited land loss (- 1.19 to - 8.35%) while small islets lost 13.17 to 28.45% of their initial land area. Islands and islets exhibited contrasting responses depending on their location, topography and vegetation type. Depending on islands, the retreat of the vegetation line occurred either along all shorelines, or along ocean shoreline only. The structure (wooded vs. grassy) and origin (native vs. introduced) of the vegetation played a major role in island response. Five days after the cyclone, beach width and beach area were multiplied by 1.5 to 10, depending on the setting, and were interpreted as resulting from both sediment reworking and the supply of large amounts of fresh sediments by the reef outer slopes to the island system. Fourth months after the cyclone, extended sheets of loose sediments were still present on the reef flat and in inter-islet channels and shallow lagoon waters, indicating continuing sediment transfer to islands. As a reminder (see Section 3.1.4), beach width uncertainty equals to 6 m for all beach sections.

  9. Exploring Mosquito Fauna of Majuro Atoll (Republic of Marshall Islands) in the Context of Zika Outbreak.

    Science.gov (United States)

    Marie, Jérôme; Perera, Devika; Garstang, Helentina; Bossin, Herve C; Bourtzis, Kostas

    2018-04-09

    First autochthonous Zika clinical case was reported in the Republic of Marshall Islands (RMI) on Majuro Atoll in February 2016. An entomological survey of mosquito larvae and adult populations was carried out in four areas of Majuro, the most populated atoll of RMI encompassing different habitats (forest, rural, or urban) including some with confirmed clinical Zika cases to evaluate which mosquito species could be involved in the Zika transmission. A total of 2,367 immature and adult mosquito specimens were collected and identified to the species level. In total, five mosquito species were detected, Aedes aegypti (Linnaeus), Aedes albopictus (Skuse), Aedes marshallensis (Stone and Bohart), Culex quinquefasciatus (Say), and Culex annulirostris (Skuse) (Diptera: Culicidae), a first record for RMI. The most abundant species was Ae. aegypti presumed to be the main vector of Zika virus followed by Ae. albopictus. Improved management of breeding containers through better public awareness and community engagement, mosquito surveillance and innovative mosquito control strategies using the sterile insect technique (SIT) and/or the incompatible insect technique (IIT) could help prevent outbreaks of arboviruses in the RMI.

  10. The terrestrial phosphorus economy of mid-Pacific atolls: Implications for the future

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, K.A. [Auckland Univ. (New Zealand). Dept. of Geology

    1998-03-01

    Major subsystems of the terrestrial phosphorus cycle on the densely populated, 142 ha motu of Fogafale, are: carbonate substrate ({approx} 10{sup 3} g P t{sup -1}), groundwater ({approx} 0.4 g P t{sup -1}), terrestrial flora ({approx} 0.22 t P ha{sup -1}) and fauna ({approx} 18 kg P ha{sup -1}). Freshwater provides the principal medium for terrestrial geochemical atoll processes and is the central recycling plant for phosphorus from atmospheric fallout and decomposition of biotic waste. Present data cannot determine precise fluxes within and between all subsystems, but perturbations, resulting from increasing human populations and changing land use, may be estimated. Changes in Fogafale`s biotic phosphorus capitals and increasing phosphorus-containing imports have skewed fluxes and transfer routes of biogenic waste. Atolls are dynamic systems, able to recover from environmental disruptions, but the sustainability and effectiveness of underlying biogeochemical cycles require quantification, monitoring and nurturing. In particular, the integrity of Fogafale`s essential fresh groundwater needs to be ascertained and protected 40 refs, 7 figs, 2 tabs

  11. Hydrogeology and geochemistry of the freshwater lens on Roi Namur atoll, the Republic of the Marshall Islands

    Science.gov (United States)

    Swarzenski, P. W.

    2015-12-01

    More than 90% of the world's ~400 larger atoll islands are located in the Pacific and Indian Oceans and are inhabited by ~ 3/4 million people. As ground elevations of these atolls rarely exceed a few meters above mean sea level, atoll communities must rely precariously on finite resources, including fresh water and land. When demand for water exceeds precipitation rates, fresh groundwater may provide an additional, albeit also limited resource. The shape and size of this freshwater lens is controlled by precipitation, infiltration, discharge, and groundwater pumping, as well as hydrogeologic characteristics of the aquifer, and climate. Small atoll islands like Roi Namur on Kwajalein perhaps best illustrate the strong interdependence of the islet's depositional history and geochemical transformations that occur within the shallow aquifer and its host rock. This study utilized electrical resistivity tomography (ERT) to define the position of the freshwater lens above underlying seawater and to examine scales of freshwater /saltwater mixing. Time series Rn-222 measurements were used to evaluate groundwater discharge rates to the coastal waters, and a suite of groundwater geochemical tracers, including select nutrients, trace elements, and water isotopes, were used to develop a better understanding of how the fresh water lens will likely to respond to external perturbations, such as managed recharge, and the inevitability of future marine over wash events that will be become more frequent and severe under expected sea level rise.

  12. One-meter topobathymetric digital elevation model for Majuro Atoll, Republic of the Marshall Islands, 1944 to 2016

    Science.gov (United States)

    Palaseanu-Lovejoy, Monica; Poppenga, Sandra K.; Danielson, Jeffrey J.; Tyler, Dean J.; Gesch, Dean B.; Kottermair, Maria; Jalandoni, Andrea; Carlson, Edward; Thatcher, Cindy A.; Barbee, Matthew M.

    2018-03-30

    Atoll and island coastal communities are highly exposed to sea-level rise, tsunamis, storm surges, rogue waves, king tides, and the occasional combination of multiple factors, such as high regional sea levels, extreme high local tides, and unusually strong wave set-up. The elevation of most of these atolls averages just under 3 meters (m), with many areas roughly at sea level. The lack of high-resolution topographic data has been identified as a critical data gap for hazard vulnerability and adaptation efforts and for high-resolution inundation modeling for atoll nations. Modern topographic survey equipment and airborne lidar surveys can be very difficult and costly to deploy. Therefore, unmanned aircraft systems (UAS) were investigated for collecting overlapping imagery to generate topographic digital elevation models (DEMs). Medium- and high-resolution satellite imagery (Landsat 8 and WorldView-3) was investigated to derive nearshore bathymetry.The Republic of the Marshall Islands is associated with the United States through a Compact of Free Association, and Majuro Atoll is home to the capital city of Majuro and the largest population of the Republic of the Marshall Islands. The only elevation datasets currently available for the entire Majuro Atoll are the Shuttle Radar Topography Mission and the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model Version 2 elevation data, which have a 30-m grid-cell spacing and a 8-m vertical root mean square error (RMSE). Both these datasets have inadequate spatial resolution and vertical accuracy for inundation modeling.The final topobathymetric DEM (TBDEM) developed for Majuro Atoll is derived from various data sources including charts, soundings, acoustic sonar, and UAS and satellite imagery spanning over 70 years of data collection (1944 to 2016) on different sections of the atoll. The RMSE of the TBDEM over the land area is 0.197 m using over 70,000 Global Navigation Satellite

  13. Remediation and rehabilitation programmes in the Marshall Islands

    International Nuclear Information System (INIS)

    McEwan, A.C.

    2000-01-01

    Following cessation of nuclear testing in the Marshall Islands in 1958 the northern atolls have been subject to extensive studies of their radiological status with a view to the return of displaced residents. In the case of Bikini an assessment was most recently carried out at the request of the Marshall Islands Government by the IAEA, based on data obtained through the DOE funded studies of Lawrence Livermore National Laboratory and the Nationwide Radiological Study undertaken for the Marshall Islands Government. For a diet of entirely local foodstuffs the mean adult annual dose to residents could be about 15 mSv, and greater than a generic reference level for intervention of 10 mSv/a. A more likely diet with some imported foods, however, would incur annual doses of about 4 mSv. Remediation in the form of potassium fertilizer application, which suppresses the uptake of Cs-137 in plants, has been recommended. In the case of Rongelap Atoll, conditions for resettlement were established in a Memorandum of Understanding (MOU) between US Government agencies and the Rongelap community. This required that annual doses to the maximally exposed resident not exceed I mSv. A number of independent evaluations and reviews found that some residents could exceed this compliance level and again remediation measures have been recommended, primarily the application of potassium to soil. It is, however, doubtful whether any remediation is justifiable on solely radiological grounds. The Rongelap MOU also specified an activity concentration limit for transuranics in soil, but this additional constraint could be considered confusing and unnecessary, particularly when it appeared to have no derivable connection to the compliance dose value. (author)

  14. An assessment of potential health impacts on Utrok Atoll from exposure to cesium-137 (137Cs) and plutonium

    International Nuclear Information System (INIS)

    Hamilton, T

    2007-01-01

    Residual fallout contamination from the nuclear test program in the Marshall Islands is a concern to Marshall Islanders because of the potential health risks associated with exposure to residual fallout contamination in the environment. Scientists from Lawrence Livermore National Laboratory (LLNL) have been monitoring the amount of fallout radiation delivered to Utrok Atoll residents over the past 4 years. This briefing document gives an outline of our findings from the whole body counting and plutonium bioassay monitoring programs. Additional information can be found on the Marshall Islands web site (http://eed.lnl.gov/mi/). Cesium-137 is an important radioactive isotope produced in nuclear detonations and can be taken up from coral soils into locally grown food crop products that form an important part of the Marshallese diet. The Marshall Islands whole body counting program has clearly demonstrated that the majority of Utrok Atoll residents acquire a very small but measurable quantity of cesium-137 in their bodies (Hamilton et al., 2006; Hamilton et. al., 2007a; 2007b;). During 2006, a typical resident of Utrok Atoll received about 3 mrem of radiation from internally deposited cesium-137 (Hamilton et al., 2007a). The population-average dose contribution from cesium-137 is around 2% of the total radiation dose that people normally experience from naturally occurring radiation sources in the Marshall Islands and is thousands of times lower than the level where radiation exposure is known to produce measurable health effects. The existing dose estimates from the whole body counting and plutonium bioassay programs are also well below radiological protection standards for protection of the public as prescribed by U.S. regulators and international agencies including the Marshall Islands Nuclear Claim Tribunal (NCT). Similarly, the level of internally deposited plutonium found in Utrok Atoll residents is well within the range normally expected for people living in the

  15. Projected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands

    Science.gov (United States)

    Shope, James B.; Storlazzi, Curt D.; Hoeke, Ron K.

    2017-10-01

    Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. It is unclear how shoreline wave run-up and erosion patterns along these low elevation islands will respond to projected sea-level rise (SLR) and changes in wave climate over the next century, hindering communities' preparation for the future. To elucidate how these processes may respond to climate change, extreme boreal winter and summer wave conditions under future sea-level rise (SLR) and wave climate scenarios were simulated at two atolls, Wake and Midway, using a shallow-water hydrodynamic model. Nearshore wave conditions were used to compute the potential longshore sediment flux along island shorelines via the CERC empirical formula and wave-driven erosion was calculated as the divergence of the longshore drift; run-up and the locations where the run-up exceed the berm elevation were also determined. SLR is projected to predominantly drive future island morphological change and flooding. Seaward shorelines (i.e., ocean fronted shorelines directly facing incident wave energy) were projected to experience greater erosion and flooding with SLR and in hypothetical scenarios where changes to deep water wave directions were altered, as informed by previous climate change forced Pacific wave modeling efforts. These changes caused nearshore waves to become more shore-normal, increasing wave attack along previously protected shorelines. With SLR, leeward shorelines (i.e., an ocean facing shoreline but sheltered from incident wave energy) became more accretive on windward islands and marginally more erosive along leeward islands. These shorelines became more accretionary and subject to more flooding with nearshore waves becoming more shore-normal. Lagoon shorelines demonstrated the greatest SLR-driven increase in erosion and run-up. They exhibited the greatest relative change with increasing wave heights where both erosion and run-up magnitudes increased. Wider

  16. Projected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands

    Science.gov (United States)

    Shope, James B.; Storlazzi, Curt; Hoeke, Ron

    2017-01-01

    Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. It is unclear how shoreline wave run-up and erosion patterns along these low elevation islands will respond to projected sea-level rise (SLR) and changes in wave climate over the next century, hindering communities' preparation for the future. To elucidate how these processes may respond to climate change, extreme boreal winter and summer wave conditions under future sea-level rise (SLR) and wave climate scenarios were simulated at two atolls, Wake and Midway, using a shallow-water hydrodynamic model. Nearshore wave conditions were used to compute the potential longshore sediment flux along island shorelines via the CERC empirical formula and wave-driven erosion was calculated as the divergence of the longshore drift; run-up and the locations where the run-up exceed the berm elevation were also determined. SLR is projected to predominantly drive future island morphological change and flooding. Seaward shorelines (i.e., ocean fronted shorelines directly facing incident wave energy) were projected to experience greater erosion and flooding with SLR and in hypothetical scenarios where changes to deep water wave directions were altered, as informed by previous climate change forced Pacific wave modeling efforts. These changes caused nearshore waves to become more shore-normal, increasing wave attack along previously protected shorelines. With SLR, leeward shorelines (i.e., an ocean facing shoreline but sheltered from incident wave energy) became more accretive on windward islands and marginally more erosive along leeward islands. These shorelines became more accretionary and subject to more flooding with nearshore waves becoming more shore-normal. Lagoon shorelines demonstrated the greatest SLR-driven increase in erosion and run-up. They exhibited the greatest relative change with increasing wave heights where both erosion and run-up magnitudes increased. Wider

  17. An investigation into the prevalence of thyroid disease on Kwajalein Atoll, Marshall Islands.

    Science.gov (United States)

    Takahashi, T; Trott, K R; Fujimori, K; Simon, S L; Ohtomo, H; Nakashima, N; Takaya, K; Kimura, N; Satomi, S; Schoemaker, M J

    1997-07-01

    The prevalence of thyroid nodules and thyroid cancer was studied in the indigenous population residing on Ebeye Island, Kwajalein Atoll, in the Republic of the Marshall Islands. This island, centrally located in the nation, is home to about 25% of the nation's population, many who have migrated there from other atolls. The objective of the study was to obtain thyroid disease rate statistics on as much of the population as possible that was alive during the years of nuclear testing and to test the hypothesis that described a linearly decreasing prevalence of palpable nodules with increasing distance from the Bikini test site. 1,322 Marshallese born before 1965 were given a thyroid examination using neck palpation, fine needle aspiration biopsy, and high resolution ultrasound imaging. Approximately 40% of the total population living on this island who are at risk from exposure to radioactive fallout during the years 1946-1958 were screened. Of that group, 815 were alive at the time of the BRAVO test on 1 March 1954. Two hundred sixty-six people with thyroid nodules were found (32.6%): 132 were palpable nodules (16.2%), and 134 were nodules that could be diagnosed with ultrasound only (15.7%). Prevalence of palpable nodules was particularly high in men and women older than 60 y, in men who were 6 to 15 y of age at the time of the BRAVO test, and in women 1 to 10 y of age at the time of the BRAVO test. In 22 people, the clinical diagnosis was most likely cancer though histopathological evidence was only available from 11 operated cases. Of the 11 operated cases, 10 were cancer. Cancer prevalence was particularly high in those women born between 1944 and 1953 (7/220 = 3.2%), i.e., who were children during the early years of nuclear testing. The Ebeye data showed a marginally significant correlation between palpable nodule prevalence among women and distance to Bikini (r = -0.44, p = 0.06). This report summarizes the clinical findings of the thyroid examinations, the age

  18. 1998 Inventory of Endangered Species and Wildlife Resources at the US Army Kwajalein Atoll, Republic of the Marshall Islands (NODC Accession 0000631)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report summarizes the results of the second United States Army Kwajalein Atoll (USAKA) Activities in the Republic of the Marshall Islands (UES) inventory of...

  19. Investigation of the marine communities of Midway Harbor and adjacent lagoon, Midway Atoll, Northwest Hawaiian Islands in 1998 (NODC Accession 0001098)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A survey of the marine communities of Midway Atoll harbor and surrounding lagoon was conducted at 12 sites from September 5 to 9, 1998. The primary focus of these...

  20. CRED Reson 8101 multibeam backscatter data of Palmyra Atoll, Pacific Remote Island Areas, Central Pacific with 1 meter resolution in netCDF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the lagoon, shelf, and slope environments of Palmyra Atoll, Pacific Island Areas, Central Pacific....

  1. Inventory of endangered species and wildlife resources at the US Army Kwajalein Atoll, Republic of the Marshall Islands, 1988 (NODC Accession 0000631)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An inventory of endangered species and the wildlife resources at the US Army Kwajelein Atoll, Republic of the Marshall Island were conducted from 30 October 1998 to...

  2. 1996 Inventory of Endangered Species and Wildlife Resources on US Army Kwajalein Atoll, Republic of the Marshall Islands (NODC Accession 0000251)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report summarizes the results of the first United States Army Kwajalein Atoll (USAKA) Activities in the Republic of the Marshall Islands (UES) inventory of...

  3. Frequency distribution, isotopic composition and physical characterization of plutonium-bearing particles from the Fig-Quince zone on Runit Island, Enewetak Atoll

    International Nuclear Information System (INIS)

    Hamilton, T.F.; Martinelli, R.E.; Kehl, S.R.; Rivers, A.N.; Brown, T.A.; Tumey, S.J.; Jernstroeem, J.; Williams, R.W.

    2009-01-01

    Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946-58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area near the GZ. A second low-yield device was detonated on the same site 10 days later, further disturbing the soil and leaving behind a very heterogeneous pattern of contamination including milligram-size particles of plutonium. A limited cleanup of the Fig-Quince zone was carried out in 1979. During this period, the effectiveness of the cleanup operations was primarily evaluated on the basis of bulk soil concentration data with little consideration given to the heterogeneity and long-term material-, biological-, and environmental-specific impacts of residual high activity (hot) particle contamination. The aim of the present study was twofold; (i) to characterize the levels and distribution of residual contamination in the Fig-Quince zone, and (ii) to develop pertinent data on the frequency distribution, elemental and isotopic composition, and physico-chemical properties of hot particles isolated from surface soils from Fig-Quince with a view towards providing recommendations on the future management and possible cleanup of the site. Today, Runit Island remains under an administrative quarantine. (author)

  4. In situ determination of 241Am on Enewetak Atoll. Date of survey: July 1977-December 1979

    International Nuclear Information System (INIS)

    Tipton, W.J.; Fritzsche, A.E.; Jaffe, R.J.; Villaire, A.E.

    1981-11-01

    An in situ gamma ray spectrometer system was operated at Enewetak Atoll from July 1977 to December 1979 in support of the Enewetak Cleanup Project. The system employed a high purity germanium planar detector suspended at a height of 7.4 m above ground. Conversion factors were established to relate measured photopeak count rate data to source concentration in the soil. Data obtained for 241 Am, together with plutonium-to-americium ratios obtained from soil sample analyses, were used to establish area-averaged surface (0 to 3 cm) transuranic concentration values. In areas which exceeded cleanup criteria, measurements were made in an iterative fashion to guide soil removal until levels were reduced below the cleanup criteria. Final measurements made after soil removal had been completed were used to document remaining surface transuranic concentration values and to establish external exposure rate levels due to 137 Cs and 60 Co

  5. An improved method for removing transuranics from coral soil at Johnston Atoll

    International Nuclear Information System (INIS)

    Moroney, J.D. III.; Johnson, N.R.; Moroney, K.S.; Mercier, J.R.

    1992-01-01

    An improved approach for removing mixed plutonium and americium contamination from coral soil matrix at the Defense Nuclear Agency's (DNA's) Johnston Atoll site has been developed by DNA's contractor, TMA/Eberline. The system uses arrays of sensitive radiation detectors coupled with sophisticated computer software newly designed by Eberline Instrument Corporation. The software controls a unique segmented gate methodology for removing contaminated soil from a moving feed supply on conveyor belts. Contaminated soil is diverted to a metal drum for collecting larger sized 'hot' particles (< 5,000 Becquerels) or to a soil washing process designed to remove dispersed low level contamination from a soil fraction consisting of very small particles. Low to intermediate levels of contamination are removed from the soil to meet DNAs criteria for release for unrestricted use based on US EPA guidelines

  6. Redistribution of fallout radionuclides in Enewetak Atoll lagoon sediments by callianassid bioturbation.

    Science.gov (United States)

    McMurtry, G M; Schneider, R C; Colin, P L; Buddemeier, R W; Suchanek, T H

    The lagoon sediments of Enewetak Atoll in the Marshall Islands contain a large selection of fallout radionuclides as a result of 43 nuclear weapon tests conducted there between 1948 and 1958. Studies of the burial of fallout radionuclides have been conducted on the islands and in several of the large craters, but studies of their vertical distribution have been limited to about the upper 20 cm of the lagoon sediments. We have found elevated fallout radionuclide concentrations buried more deeply in the lagoon sediments and evidence of burrowing into the sediment by several species of callianassid ghost shrimp (Crustacea: Thalassinidea) which has displaced highly radioactive sediment. The burrowing activities of callianassids, which are ubiquitous on the lagoon floor, facilitate radionuclide redistribution and complicate the fallout radionuclide inventory of the lagoon.

  7. Human impacts on large benthic foraminifers near a densely populated area of Majuro Atoll, Marshall Islands.

    Science.gov (United States)

    Osawa, Yoko; Fujita, Kazuhiko; Umezawa, Yu; Kayanne, Hajime; Ide, Yoichi; Nagaoka, Tatsutoshi; Miyajima, Toshihiro; Yamano, Hiroya

    2010-08-01

    Human impacts on sand-producing, large benthic foraminifers were investigated on ocean reef flats at the northeast Majuro Atoll, Marshall Islands, along a human population gradient. The densities of dominant foraminifers Calcarina and Amphistegina declined with distance from densely populated islands. Macrophyte composition on ocean reef flats differed between locations near sparsely or densely populated islands. Nutrient concentrations in reef-flat seawater and groundwater were high near or on densely populated islands. delta(15)N values in macroalgal tissues indicated that macroalgae in nearshore lagoons assimilate wastewater-derived nitrogen, whereas those on nearshore ocean reef flats assimilate nitrogen from other sources. These results suggest that increases in the human population result in high nutrient loading in groundwater and possibly into nearshore waters. High nutrient inputs into ambient seawater may have both direct and indirect negative effects on sand-producing foraminifers through habitat changes and/or the collapse of algal symbiosis. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. Human impacts on large benthic foraminifers near a densely populated area of Majuro Atoll, Marshall Islands

    International Nuclear Information System (INIS)

    Osawa, Yoko; Fujita, Kazuhiko; Umezawa, Yu; Kayanne, Hajime; Ide, Yoichi; Nagaoka, Tatsutoshi; Miyajima, Toshihiro; Yamano, Hiroya

    2010-01-01

    Human impacts on sand-producing, large benthic foraminifers were investigated on ocean reef flats at the northeast Majuro Atoll, Marshall Islands, along a human population gradient. The densities of dominant foraminifers Calcarina and Amphistegina declined with distance from densely populated islands. Macrophyte composition on ocean reef flats differed between locations near sparsely or densely populated islands. Nutrient concentrations in reef-flat seawater and groundwater were high near or on densely populated islands. δ 15 N values in macroalgal tissues indicated that macroalgae in nearshore lagoons assimilate wastewater-derived nitrogen, whereas those on nearshore ocean reef flats assimilate nitrogen from other sources. These results suggest that increases in the human population result in high nutrient loading in groundwater and possibly into nearshore waters. High nutrient inputs into ambient seawater may have both direct and indirect negative effects on sand-producing foraminifers through habitat changes and/or the collapse of algal symbiosis.

  9. Concentrations of radionuclides in fish collected from Bikini Atoll between 1977 and 1984

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Wong, K.M.; Eagle, R.J.; Jokela, T.A.; Brunk, J.A.

    1986-07-01

    This report summarizes all available data on the concentrations of radionuclides in fish from Bikini Atoll between 1977 and 1984. As found in other global studies, 137 Cs is most highly accumulated in edible flesh of all species of fish, the lowest fractions are found in the bone or liver. The mean concentration of 137 Cs in muscle of reef fish from the southern part of the atoll is comparable to the global fallout concentration measured in market samples of fish collected from Chicago, Illinois, in 1982. 90 Sr is generally associated with non-edible parts of fish, such as bone or viscera. Twenty-five to fifty percent of the total body burden of 60 Co is accumulated in the muscle tissue; the remainder is distributed among the liver, skin, and viscera. The mean concentration of 60 Co in fish has been decreasing at a rate faster than radiological decay alone. Most striking is the range of 207 Bi concentrations among different species of fish collected at the same time and place. Highest concentrations of 207 Bi were consistently detected in the muscle (and other tissues) of goatfish and some of the pelagic lagoon fish. In other reef fish, such as mullet, surgeonfish, and parrotfish, 207 Bi was usually below detection limits by gamma spectrometry. Over 70% of the whole-body activity of 207 Bi in goatfish is associated with the muscle tissue, whereas less than 5% is found in the muscle of mullet and surgeonfish. Neither 239+240 Pu nor 241 Am is significantly accumulated in the muscle tissue of any species of fish. Apparently, 238 Pu is in a more readily available form for accumulation by fishes than 239+240 Pu. Based on a daily ingestion rate of 200 q of fish flesh, dose rates to individuals through the fish-food ingestion pathway are well below current Federal guidelines

  10. An updated dose assessment for a U.S. Nuclear Test Site - Bikini Atoll

    International Nuclear Information System (INIS)

    Robison, W.L.; Bogen, K.T.; Conrado, C.L.

    1995-10-01

    On March 1, 1954, a nuclear weapon test, code-named BRAVO, conducted at Bikini Atoll in the northern Marshall Islands contaminated the major residence island. There has been a continuing effort since 1977 to refine dose assessments for resettlement options at Bikini Atoll. Here we provide a radiological dose assessment for the main residence island, Bikini, using extensive radionuclide concentration data derived from analysis of food crops, ground water, cistern water, fish and other marine species, animals, air, and soil collected at Bikini Island as part of our continuing research and monitoring program that began in 1975. The unique composition of coral soil greatly alters the relative contribution of cesium-137 ( 137 Cs) and strontium-90 ( 90 Sr) to the total estimated dose relative to expectations based on North American and European soils. Without counter measures, cesium-137 produces 96% of the estimated dose for returning residents, mostly through uptake from the soil to terrestrial food crops but also from external gamma exposure. The doses are calculated assuming a resettlement date of 1999. The estimated maximum annual effective dose for current island conditions is 4.0 mSv when imported foods, which are now an established part of the diet, are available. The corresponding 30-, 50-, and 70-y integral effective doses are 9.1 cSv, 13 cSv, and 15 cSv, respectively. A corresponding uncertainty analysis showed that after about 5 y of residence, the 95% confidence limits on population-average dose would be ±35% of its expected value. We have evaluated various countermeasures to reduce 137 Cs in food crops. Treatment with potassium reduces the uptake of 137 Cs into food crops, and therefore the ingestion dose, to about 5% of pretreatment levels and has essentially no negative environmental consequences

  11. Human impact on atolls leads to coral loss and community homogenisation: a modeling study.

    Directory of Open Access Journals (Sweden)

    Bernhard M Riegl

    Full Text Available We explore impacts on pristine atolls subjected to anthropogenic near-field (human habitation and far-field (climate and environmental change pressure. Using literature data of human impacts on reefs, we parameterize forecast models to evaluate trajectories in coral cover under impact scenarios that primarily act via recruitment and increased mortality of larger corals. From surveys across the Chagos, we investigate the regeneration dynamics of coral populations distant from human habitation after natural disturbances. Using a size-based mathematical model based on a time-series of coral community and population data from 1999-2006, we provide hind- and forecast data for coral population dynamics within lagoons and on ocean-facing reefs verified against monitoring from 1979-2009. Environmental data (currents, temperatures were used for calibration. The coral community was simplified into growth typologies: branching and encrusting, arboresent and massive corals. Community patterns observed in the field were influenced by bleaching-related mortality, most notably in 1998. Survival had been highest in deep lagoonal settings, which suggests a refuge. Recruitment levels were higher in lagoons than on ocean-facing reefs. When adding stress by direct human pressure, climate and environmental change as increased disturbance frequency and modified recruitment and mortality levels (due to eutrophication, overfishing, pollution, heat, acidification, etc, models suggest steep declines in coral populations and loss of community diversification among habitats. We found it likely that degradation of lagoonal coral populations would impact regeneration potential of all coral populations, also on ocean-facing reefs, thus decreasing reef resilience on the entire atoll.

  12. Limited trophic partitioning among sympatric delphinids off a tropical oceanic atoll.

    Directory of Open Access Journals (Sweden)

    Hillary Young

    Full Text Available Understanding trophic relationships among marine predators in remote environments is challenging, but it is critical to understand community structure and dynamics. In this study, we used stable isotope analysis of skin biopsies to compare the isotopic, and thus, trophic niches of three sympatric delphinids in the waters surrounding Palmyra Atoll, in the Central Tropical Pacific: the melon-headed whale (Peponocephala electra, Gray's spinner dolphin (Stenella longirostris longirostris, and the common bottlenose dolphin (Tursiops truncatus. δ15N values suggested that T. truncatus occupied a significantly higher trophic position than the other two species. δ13C values did not significantly differ between the three delphinds, potentially indicating no spatial partitioning in depth or distance from shore in foraging among species. The dietary niche area-determined by isotopic variance among individuals-of T. truncatus was also over 30% smaller than those of the other species taken at the same place, indicating higher population specialization or lower interindividual variation. For P. electra only, there was some support for intraspecific variation in foraging ecology across years, highlighting the need for temporal information in studying dietary niche. Cumulatively, isotopic evidence revealed surprisingly little evidence for trophic niche partitioning in the delphinid community of Palmyra Atoll compared to other studies. However, resource partitioning may happen via other behavioral mechanisms, or prey abundance or availability may be adequate to allow these three species to coexist without any such partitioning. It is also possible that isotopic signatures are inadequate to detect trophic partitioning in this environment, possibly because isotopes of prey are highly variable or insufficiently resolved to allow for differentiation.

  13. Seafloor geomorphology and geology of the Kingman Reef-Palmyra Atoll region, Central Pacific Ocean

    Science.gov (United States)

    Eakins, Barry; Barth, Ginger; Scheirer, Dan; Mosher, Dave; Armstrong, Andy

    2017-04-01

    Kingman Reef and Palmyra Atoll are the exposed summits of two seamounts within the Line Islands Volcanic Chain in the Central Pacific Ocean. Both are U.S. Territories, and the Exclusive Economic Zone around the islands was partially surveyed in 1991 with GLORIA sidescan sonar and seismic reflection profiling. New multibeam swath sonar surveys were conducted in 2010, 2015, and 2016 around the islands, in support of U.S. Extended Continental Shelf investigations. Numerous transits through the region by research vessels have collected additional multibeam swath sonar data. We present new, detailed maps of bathymetry, sidescan sonar imagery, geology, and sediment isopachs of the seafloor surrounding the islands, and how these have informed our understanding of the islands' margins. The islands are the last subaerial remnants of a complex, horse-shoe-shaped volcanic platform spanning roughly 200 km in diameter. The elevated platform from which the seamounts arise comprises at least 10 individual volcanic centers that have heights exceeding 3000m above the nearby abyssal plains. Gravity modeling suggests that the elevated platform is compensated by thickened crust. Strong carbonate caps and voluminous sediment accumulations flanking the platform indicate that the volcanoes were once shallow-water or emergent systems. These systems produced vast quantities of carbonate sediment that were shed to a deep interior basin to the east of Palmyra Atoll, and to nearby abyssal plains. The identification of mass failures, sediment reworking and bedforms, and channel networks provide evidence for extensive sedimentary processes around these volcanic centers. Analysis of the seamounts atop the elevated platform and in the seamount province to the northwest shows that flat-topped seamounts ("guyots") are principally found at depths shallower than 1300 meters, while peaked seamounts are almost exclusively found at greater depths. This constrains the amount of regional subsidence that

  14. Concentrations of radionuclides in fish collected from Bikini Atoll between 1977 and 1984

    Energy Technology Data Exchange (ETDEWEB)

    Noshkin, V.E.; Wong, K.M.; Eagle, R.J.; Jokela, T.A.; Brunk, J.A.

    1986-07-01

    This report summarizes all available data on the concentrations of radionuclides in fish from Bikini Atoll between 1977 and 1984. As found in other global studies, /sup 137/Cs is most highly accumulated in edible flesh of all species of fish, the lowest fractions are found in the bone or liver. The mean concentration of /sup 137/Cs in muscle of reef fish from the southern part of the atoll is comparable to the global fallout concentration measured in market samples of fish collected from Chicago, Illinois, in 1982. /sup 90/Sr is generally associated with non-edible parts of fish, such as bone or viscera. Twenty-five to fifty percent of the total body burden of /sup 60/Co is accumulated in the muscle tissue; the remainder is distributed among the liver, skin, and viscera. The mean concentration of /sup 60/Co in fish has been decreasing at a rate faster than radiological decay alone. Most striking is the range of /sup 207/Bi concentrations among different species of fish collected at the same time and place. Highest concentrations of /sup 207/Bi were consistently detected in the muscle (and other tissues) of goatfish and some of the pelagic lagoon fish. In other reef fish, such as mullet, surgeonfish, and parrotfish, /sup 207/Bi was usually below detection limits by gamma spectrometry. Over 70% of the whole-body activity of /sup 207/Bi in goatfish is associated with the muscle tissue, whereas less than 5% is found in the muscle of mullet and surgeonfish. Neither /sup 239 +240/Pu nor /sup 241/Am is significantly accumulated in the muscle tissue of any species of fish. Apparently, /sup 238/Pu is in a more readily available form for accumulation by fishes than /sup 239 +240/Pu. Based on a daily ingestion rate of 200 q of fish flesh, dose rates to individuals through the fish-food ingestion pathway are well below current Federal guidelines.

  15. Proximity to encroaching coconut palm limits native forest water use and persistence on a Pacific atoll

    Science.gov (United States)

    Krauss, Ken W.; Duberstein, Jamie A.; Cormier, Nicole; Young, Hillary S.; Hathaway, Stacie A.

    2015-01-01

    Competition for fresh water between native and introduced plants is one important challenge facing native forests as rainfall variability increases. Competition can be especially acute for vegetation on Pacific atolls, which depend upon consistent rainfall to replenish shallow groundwater stores. Patterns of sap flow, water use, and diameter growth of Pisonia grandis trees were investigated on Sand Islet, Palmyra Atoll, Line Islands, during a period of low rainfall. Sap flow in the outer sapwood was reduced by 53% for P. grandis trees growing within coconut palm (Cocos nucifera) stands (n = 9) versus away from coconut palm (n = 9). This suggested that water uptake was being limited by coconut palm. Radial patterns of sap flow into the sapwood of P. grandis also differed between stands with and without coconut palm, such that individual tree water use for P. grandis ranged from 14 to 67 L day−1, averaging 47·8 L day−1 without coconut palm and 23·6 L day−1 with coconut palm. Diameter growth of P. grandis was measured from nine islets. In contrast to sap flow, competition with coconut palm increased diameter growth by 89%, equating to an individual tree basal area increment of 5·4 versus 10·3 mm2 day−1. Greater diameter growth countered by lower rates of water use by P. grandis trees growing in competition with coconut palm suggests that stem swell may be associated with water storage when positioned in the understory of coconut palm, and may facilitate survival when water becomes limiting until too much shading overwhelms P. grandis. 

  16. Stomach nematodes (Mastophorus Muris) in rats (Rattus rattus) are associated with coconut (Cocos nucifera) Habitat at palmyra atoll

    Science.gov (United States)

    Lafferty, K.D.; Hathaway, S.A.; Wegmann, A.S.; Shipley, F.S.; Backlin, A.R.; Helm, J.; Fisher, R.N.

    2010-01-01

    Black rats (Rattus rattus) and their stomach nematodes (Mastophorus muris) were historically introduced to islets at Palmyra Atoll in the central Pacific Line Islands. To investigate patterns of parasitism, we trapped rats and quantified nematodes on 13 islets of various sizes and habitat types. Most rats were parasitized (59) with an average of 12 worms per infected rat. Islet size did not greatly influence parasite population biology. Nematodes also did not appear to affect rat condition (weight to skull length). The only strong and consistent factor associated with the mean abundance of nematodes in rats was habitat (dominant cover and locally dominant plant species). Thus, nematodes were much more abundant in rats from sites dominated by coconut trees (Cocos nucifera). Coconut trees may also be an introduced species at Palmyra Atoll. ?? American Society of Parasitologists 2010.

  17. Stomach nematodes (Mastophorus muris) in rats (Rattus rattus) are associated with coconut (Cocos nucifera) habitat at Palmyra Atoll.

    Science.gov (United States)

    Lafferty, Kevin D; Hathaway, Stacie A; Wegmann, Alex S; Shipley, Frank S; Backlin, Adam R; Helm, Joel; Fisher, Robert N

    2010-02-01

    Black rats ( Rattus rattus ) and their stomach nematodes (Mastophorus muris) were historically introduced to islets at Palmyra Atoll in the central Pacific Line Islands. To investigate patterns of parasitism, we trapped rats and quantified nematodes on 13 islets of various sizes and habitat types. Most rats were parasitized (59%) with an average of 12 worms per infected rat. Islet size did not greatly influence parasite population biology. Nematodes also did not appear to affect rat condition (weight to skull length). The only strong and consistent factor associated with the mean abundance of nematodes in rats was habitat (dominant cover and locally dominant plant species). Thus, nematodes were much more abundant in rats from sites dominated by coconut trees (Cocos nucifera). Coconut trees may also be an introduced species at Palmyra Atoll.

  18. Geochronology and subsurface stratigraphy of Pukapuka and Rakahanga atolls, Cook Islands: Late Quaternary reef growth and sea level history

    Science.gov (United States)

    Gray, S.C.; Hein, J.R.; Hausmann, R.; Radtke, U.

    1992-01-01

    Eustatic sea-level cycles superposed on thermal subsidence of an atoll produce layers of high sea-level reefs separated by erosional unconformities. Coral samples from these reefs from cores drilled to 50 m beneath the lagoons of Pukapuka and Rakahanga atolls, northern Cook Islands give electron spin resonance (ESR) and U-series ages ranging from the Holocene to 600,000 yr B.P. Subgroups of these ages and the stratigraphic position of their bounding unconformities define at least 5 periods of reef growth and high sea-level (0-9000 yr B.P., 125,000-180,000 yr B.P., 180,000-230,000 yr B.P., 300,000-460,000 yr B.P., 460,000-650,000 yr B.P.). Only two ages fall within error of the last interglacial high sea-level stand (???125,000-135,000 yr B.P.). This paucity of ages may result from extensive erosion of the last intergracial reef. In addition, post-depositional isotope exchange may have altered the time ages of three coral samples to apparent ages that fall within glacial stage 6. For the record to be preserved, vertical accretion during rising sea-level must compensate for surface lowering from erosion during sea-level lowstands and subsidence of the atoll; erosion rates (6-63 cm/1000 yr) can therefore be calculated from reef accretion rates (100-400 cm/1000 yr), subsidence rates (2-6 cm/1000 yr), and the duration of island submergence (8-15% of the last 600,000 yr). The stratigraphy of coral ages indicates island subsidence rates of 4.5 ?? 2.8 cm/1000 yr for both islands. A model of reef growth and erosion based on the stratigraphy of the Cook Islands atolls suggests average subsidence and erosion rates of between 3-6 and 15-20 cm/1000 yr, respectively. ?? 1992.

  19. Weights, hematology and serum chemistry of free-ranging brown boobies (Sula leucogaster) in Johnston Atoll, Central Pacific

    Science.gov (United States)

    Work, Thierry M.

    1999-01-01

    Hematologic and serum chemistry values are reported for 105 brown boobies (Sula leucogaster) from Johnston Atoll, Central Pacific. Hematocrit, estimated total plasma solids, total and differential white cell counts, serum glucose, calcium, phosphorus, uric acid, total protein, albumin, globulin, aspartate aminotransferase, and creatinine phosphokinase were analyzed. Hematologic and serum chemistry values varied with age and sex. Values were compared with those of red-footed boobies and other tropical and temperate marine pelecaniforms.

  20. Trophic interactions between larger crocodylians and giant tortoises on Aldabra Atoll, Western Indian Ocean, during the Late Pleistocene.

    Science.gov (United States)

    Scheyer, Torsten M; Delfino, Massimo; Klein, Nicole; Bunbury, Nancy; Fleischer-Dogley, Frauke; Hansen, Dennis M

    2018-01-01

    Today, the UNESCO World Heritage Site of Aldabra Atoll is home to about 100 000 giant tortoises, Aldabrachelys gigantea , whose fossil record goes back to the Late Pleistocene. New Late Pleistocene fossils (age ca . 90-125 000 years) from the atoll revealed some appendicular bones and numerous shell fragments of giant tortoises and cranial and postcranial elements of crocodylians. Several tortoise bones show circular holes, pits and scratch marks that are interpreted as bite marks of crocodylians. The presence of a Late Pleistocene crocodylian species, Aldabrachampsus dilophus , has been known for some time, but the recently found crocodylian remains presented herein are distinctly larger than those previously described. This indicates the presence of at least some larger crocodylians, either of the same or of a different species, on the atoll. These larger crocodylians, likely the apex predators in the Aldabra ecosystem at the time, were well capable of inflicting damage on even very large giant tortoises. We thus propose an extinct predator-prey interaction between crocodylians and giant tortoises during the Late Pleistocene, when both groups were living sympatrically on Aldabra, and we discuss scenarios for the crocodylians directly attacking the tortoises or scavenging on recently deceased animals.

  1. Arthropods of Rose Atoll with special reference to ants and Pulvinaria Urbicola Scales (Hempitera Coccidae) on Pisonia Grandis trees

    Science.gov (United States)

    Banko, Paul C.; Peck, Robert W.; Pendleton, Frank; Schmaedick, Mark; Ernsberger, Kelsie

    2014-01-01

    Rose Atoll, at the eastern end of the Samoan Archipelago, is a small but important refuge for seabirds, shorebirds, and sea turtles. While the vertebrate community is relatively well-studied, the terrestrial arthropod fauna, and its role in ecosystem function, are poorly known. Arthropods may be influencing the decline of Pisonia grandis, an ecologically important tree that once dominated the 6.6 ha of land on Rose Atoll. Reasons for the decline are not fully understood but a facultative relationship between two invasive arthropods, the soft scale Pulvinaria urbicola and ants, likely has contributed to tree death. The primary objectives of this study were to systematically survey the terrestrial arthropod fauna and identify ant species that tend scales on Pisonia. Using an array of standard arthropod collecting techniques, at least 73 species from 20 orders were identified, including nine ant species. Of the ants collected, only Tetramorium bicarinatum and T. simillimum were observed tending scales on Pisonia. No known natural enemies of Pulvinaria scales were found, suggesting little predation on scale populations. Treatment of Pisonia with the systemic insecticide imidacloprid failed to eliminate Pulvinaria scales, although short-term suppression apparently occurred. The arthropod fauna of Rose Atoll is dominated by exotic species that likely have a significant impact on the structure and function of the island’s ecosystem.

  2. Clipperton Atoll (eastern Pacific): oceanography, geomorphology, reef-building coral ecology and biogeography

    Science.gov (United States)

    Glynn, P. W.; Veron, J. E. N.; Wellington, G. M.

    1996-06-01

    Coral reef geomorphology and community composition were investigated in the tropical northeastern Pacific during April 1994. Three areas were surveyed in the Revillagigedo Islands (Mexico), and an intensive study was conducted on Clipperton Atoll (1,300 km SW of Acapulco), including macro-scale surface circulation, sea surface temperature (SST) climatology, geomorphology, coral community structure, zonation, and biogeography. Satellite-tracked drifter buoys from 1979 1993 demonstrated complex patterns of surface circulation with dominantly easterly flow (North Equatorial Counter Current, NECC), but also westerly currents (South Equatorial Current, SEC) that could transport propagules to Clipperton from both central and eastern Pacific regions. The northernmost latitude reached by the NECC is not influenced by El Niño-Southern Oscillation (ENSO) events, but easterly flow velocity evidently is accelerated at such times. Maximum NECC flow rates indicate that the eastern Pacific barrier can be bridged in 60 to 120 days. SST anomalies at Clipperton occur during ENSO events and were greater at Clipperton in 1987 than during 1982 1983. Shallow (15 18 m)and deep (50 58 m) terraces are present around most of Clipperton, probably representing Modern and late Pleistocene sea level stands. Although Clipperton is a well developed atoll with high coral cover, the reef-building fauna is depauperate, consisting of only 7 species of scleractinian corals belonging to the genera Pocillopora, Porites, Pavona and Leptoseris, and 1 species of hydrocoral in the genus Millepora. The identities of the one Pocilpopora species and one of the two Porites species are still unknown. Two of the remaining scleractinians ( Pavona minuta, Leptoseris scabra) and the hydrocoral ( Millepora exaesa), all formerly known from central and western Pacific localities, represent new eastern Pacific records. Scleractinian corals predominate (10 100% cover) over insular shelf depths of 8 to 60m, and crustose

  3. Past and present levels of some radionuclides in fish from Bikini and Enewetak Atolls.

    Science.gov (United States)

    Noshkin, V E; Robison, W L; Wong, K M; Brunk, J L; Eagle, R J; Jones, H E

    1997-07-01

    Bikini and Enewetak were the sites in the Northern Marshall Islands that were used by the United States as testing grounds for nuclear devices between 1946 and 1958. The testing produced close-in fallout debris that was contaminated with different radionuclides and which entered the aquatic environment. The contaminated lagoon sediments became a reservoir and source term of manmade radionuclides for the resident marine organisms. This report contains a summary of all the available data on the concentrations of 137Cs, 60Co and 207Bi in flesh samples of reef and pelagic fish collected from Bikini and Enewetak Atolls between 1964 and 1995. The selection of these three radionuclides for discussion is based on the fact that these are the only radionuclides that have been routinely detected by gamma spectrometry in flesh samples from all fish for the last 20 y. Flesh from fish is an important source of food in the Marshallese diet. These radionuclides along with the transuranic radionuclides and 90Sr contribute most of the small radiological dose from ingesting marine foods. Some basic relationships among concentrations in different tissues and organs are discussed. The reef fish can be used as indicator species because their body burden is derived from feeding, over a lifetime, within a relatively small contaminated area of the lagoon. Therefore, the emphasis of this report is to use this extensive and unique concentration data base to describe the effective half lives and cycling for the radionuclides in the marine environments during the 31-y period between 1964 and 1995. The results from an analysis of the radionuclide concentrations in the flesh samples indicate the removal rates for the 3 radionuclides are significantly different. 137Cs is removed from the lagoons with an effective half life of 9-12 y. Little 60Co is mobilized to the water column so that it is depleted in both environments, primarily through radioactive decay. The properties of 207Bi are different

  4. Updated radiological dose assessment of Bikini and Eneu Islands at Bikini Atoll

    International Nuclear Information System (INIS)

    Robison, W.L.; Mount, M.E.; Phillips, W.A.; Stuart, M.L.; Thompson, S.E.; Conrado, C.L.; Stoker, A.C.

    1982-01-01

    This report is part of a continuing effort to refine dose assessments for resettlement options at Bikini Atoll. Radionuclide concentration data developed at Bikini Atoll since 1977 have been used in conjunction with recent dietary information and current dose models to develop the annual dose rate and 30- and 50-y integral doses presented here for Bikini and Eneu Island living patterns. The terrestrial food chain is the most significant exposure pathway--it contributes more than 50% of the total dose--and external gamma exposure is the second most significant pathway. Other pathways evaluated are the marine food chain, drinking water, and inhalation. Cesium-137 produces more than 85% of the predicted dose; 90 Sr is the second most significant radionuclide; 60 Co contributes to the external gamma exposure in varying degrees, but is a small part of the total predicted dose; the transuranic radionuclides contribute a small portion of the total predicted lung and bone doses but do present a long-term source of exposure. Maximum annual dose rates for Bikini Island are about 1 rem/y for the whole body and bone marrow when imported foods are available and about 1.9 rem/y when imports are unavailable. Maximum annual dose rates for Eneu Island when imports are available are 130 mrem/y for the whole body and 136 mrem/y for bone marrow. Similar doses when imported foods are unavailable are 245 and 263 mrem/y, respectively. The 30-y integral doses for Bikini Island are about 23 rem for whole body and bone marrow when imported foods are available and more than 40 rem when imports are unavailable. The Eneu Island 30-y integral doses for whole body and bone marrow are about 3 rem when imports are available and 5.5 and 6.1 rem, respectively, when imports are unavailable. Doses from living patterns involving some combination of Bikini and Eneu Islands fall between the doses listed above for each island separately

  5. Revisiting wild stocks of black lip oyster Pinctada margaritifera in the Tuamotu Archipelago: The case of Ahe and Takaroa atolls and implications for the cultured pearl industry

    Science.gov (United States)

    Andréfouët, Serge; Thomas, Yoann; Dumas, Franck; Lo, Cédrik

    2016-12-01

    Spat collecting of the black lip oyster (Pinctada margaritifera) is the foundation of cultured black pearl production, the second source of income for French Polynesia. To understand spat collecting temporal and spatial variations, larval supply and its origin need to be characterized. To achieve this, it is necessary to account for the stock of oysters, its distribution and population characteristics (size distribution, sex-ratio). While the farmed stock in concessions can be easily characterized, the wild stock is elusive. Here, we investigate the distribution and population structure of the wild stock of Ahe and Takaroa atolls using fine-scale bathymetry and in situ census data. Stocks were surprisingly low (∼666,000 and ∼1,030,000 oysters for Ahe and Takaroa respectively) considering these two atolls have both been very successful spat collecting atolls in the past. Furthermore, in Ahe atoll, wild populations are aging with a dominant but small female population. Comparison with the cultured stock population (∼14 millions oysters) and its dominant young male population suggests that to maximize larval supply and spat collecting on the long term, it would be useful to increase the number of females in selected sanctuaries. We discuss the implication of our findings for the long-term management of stocks and for spat collection in pearl farming atolls, and for on-going numerical modelling studies on larval dispersal.

  6. Groundwater movement on a Low-lying Carbonate Atoll Island and its Response to Climatic and Sea-level Fluctuations: Roi Namur, Republic of the Marshall Islands

    Science.gov (United States)

    Oberle, F. J.; Swarzenski, P. W.; Storlazzi, C. D.

    2017-12-01

    Atoll islands, most of which only average 1-2 meters above today's sea level, provide a tremendous natural laboratory in which to study and better understand the intensifying impacts of high rates of sea-level rise on tropical reef-lined islands. These islands are unique and on the frontline of negative societal impacts due to their geologic structure and limited water supply. Groundwater resources on atolls are typically minimal due to the low elevation and small surface area of the islands and are also subject to recurring droughts, and more frequent, storm-driven seawater overwash events. Although groundwater is the principal means of freshwater storage on atoll islands and is a major factor in determining the overall sustainability of island settlements, hydrological data on how an aquifer will response to changes in sea-level rise or storm-driven overwash remain limited. Here we present high-resolution time series hydrogeological and geochemical data from a 16 month study to determine the role of an atoll's carbonate geology, land use, and atmospheric and oceanographic forcing in driving coastal groundwater exchange including submarine groundwater discharge on the island of Roi-Namur on Kwajalein Atoll in the Republic of the Marshall Islands. This information can provide new estimates on the recovery and resilience of coastal groundwater resources on similar islands that are expected to experience climate change-driven perturbations.

  7. ASM-Triggered Too Observations of Kilohertz Oscillations in Three Atoll Sources

    Science.gov (United States)

    Kaaret, P.; Swank, Jean (Technical Monitor)

    2000-01-01

    Three Rossi Timing Explorer (RXTE) observations were carried out for this proposal based on target of opportunity triggers derived from the All-Sky Monitor (ASM) on RXTE. We obtained short observations of 4U1636-536 (15ks) and 4U1735-44 (23ks) and a longer observation of 4U0614+091 (117ks). Our analysis of our observations of the atoll neutron star x-ray binary 4U1735-44 lead to the discovery of a second high frequency quasiperiodic oscillation (QPO) in this source. These results were published in the Astrophysical Journal Letters. The data obtained on the source 4U0614+091 were used in a comprehensive study of this source, which will be published in the Astrophysical Journal. The data from this proposal were particularly critical for that study as they lead to the detection of the highest QPO frequency every found in the x-ray emission from an x-ray binary which will be important in placing limits on the equation of state of nuclear matter.

  8. Sediment studies at Bikini Atoll part 1. distribution of fine and coarse components in surface sediments

    International Nuclear Information System (INIS)

    Noshkin, V. E.; Eagle, R.J.; Robison, W.L.

    1997-01-01

    In 1979, 21 years after the moratorium on nuclear testing in the Marshall Islands, surface sediment samples (to depths of 2 and 4 cm) were collected from 87 locations over the floor of Bikini lagoon. The main purpose for the collections was to map the distribution of long- lived man-made radionuclides associated with the bottom material. In addition the samples were processed to estimate the fraction of fine and coarse components to show what modifications occurred since the sediment composition was first described in samples collected before testing in 1946. In this report a comparison is made of the amount and distribution of fine material associated with the lagoon surface sediment before and after the testing of nuclear devices. Nuclear testing produced more finely divided material in-the surface sediment layer over large areas of the lagoon and especially in regions of the lagoon and reef adjacent to test sites. Five cratering events at Bikini Atoll generated sufficient material to account for the inventory of new fine material found over the bottom surface of the lagoon. Although the fraction of fine material in the bottom sediments was altered by the nuclear events, the combined processes of formation, transport and deposition were not sufficiently dynamic to alter the geographical features of the major sedimentary components over most of the lagoon floor

  9. Modeling patterns of coral bleaching at a remote Central Pacific atoll.

    Science.gov (United States)

    Williams, Gareth J; Knapp, Ingrid S; Maragos, James E; Davy, Simon K

    2010-09-01

    A mild bleaching event (9.2% prevalence) at Palmyra Atoll occurred in response to the 2009 ENSO, when mean water temperature reached 29.8-30.1 degrees C. Prevalence among both abundant and sparse taxa varied with no clear pattern in susceptibility relating to coral morphology. Seven taxon-specific models showed that turbidity exacerbated while prior exposure to higher background temperatures alleviated bleaching, with these predictors explaining an average 16.3% and 11.5% variation in prevalence patterns, respectively. Positive associations occurred between bleaching prevalence and both immediate temperature during the bleaching event (average 8.4% variation explained) and increased sand cover (average 3.7%). Despite these associations, mean unexplained variation in prevalence equalled 59%. Lower bleaching prevalence in areas experiencing higher background temperatures suggests acclimation to temperature stress among several coral genera, while WWII modifications may still be impacting the reefs via shoreline sediment re-distribution and increased turbidity, exacerbating coral bleaching susceptibility during periods of high temperature stress. Copyright 2010 Elsevier Ltd. All rights reserved.

  10. Gross and microscopic morphology of lesions in Cnidaria from Palmyra Atoll, Central Pacific

    Science.gov (United States)

    Williams, Gareth J.; Work, Thierry M.; Aeby, Greta S.; Knapp, Ingrid S.; Davy, Simon K.

    2011-01-01

    We conducted gross and microscopic characterizations of lesions in Cnidaria from Palmyra Atoll, Central Pacific. We found growth anomalies (GA) to be the most commonly encountered lesion. Cases of discoloration and tissue loss were rare. GAs had a focal or multi-focal distribution and were predominantly nodular, exophytic, and umbonate. In scleractinians, the majority of GAs manifested as hyperplasia of the basal body wall (52% of cases), with an associated absence or reduction of polyp structure (mesenteries and filaments, actinopharynx and tentacles), and depletion of zooxanthellae in the gastrodermis of the upper body wall. In the soft corals Sinularia sp. and Lobophytum sp., GAs exclusively manifested as prominent hyperplasia of the coenenchyme with an increased density of solenia. In contrast to scleractinians, soft coral GAs displayed an inflammatory and necrotizing component with marked edema of the mesoglea, accompanied by infiltrates of variably-sized granular amoebocytes. Fungi, algae, sponges, and Crustacea were present in some scleractinian GAs, but absent in soft coral GAs. Fragmentation of tissues was a common finding in Acropora acuminata and Montipora cf. dilatata colonies with tissue loss, although no obvious causative agents were seen. Discoloration in the zoanthid, Palythoa tuberculosa, was found to be the result of necrosis, while in Lobophytum sp. discoloration was the result of zooxanthellar depletion (bleaching). Soft corals with discoloration or tissue loss showed a marked inflammatory response, however no obvious causative organisms were seen. Lesions that appeared similar at the gross level were revealed to be distinct by microscopy, emphasizing the importance of histopathology.

  11. Report on the intercomparison run: radionuclides in seawater and plankton collected outside Mururoa Atoll

    International Nuclear Information System (INIS)

    Ballestra, S.; Noshkin, V.

    1991-07-01

    This report contains a brief outline of the sampling program and a summary of all available radiological data provided by the three participants. The Direction des Centres d'Experimentations Nucleaires Laboratory (DIRCEN-CEA), Montlhery, France; The Lawrence Livermore National Laboratory (LLNL), Livermore, CA, USA; and the IAEA International Laboratory of Marine Radioactivity, (IAEA-ILMR), Principality of Monaco. The IAEA-ILMR results are complied in a separate report by Ballestra et al. (1991) that has details of the program and copies of the protocol and the ''Proces-verbal de constat'' produced by the legal representative at the end of the sampling program. A sampling program was designed to collect 3 large volume seawater and 2 plankton samples from locations near the territorial limit outside Mururoa Atoll. The different samples were to be used for a radiological intercomparison exercise. A legal representative from Papeete, Tahiti (French Polynesia) was given the task to verify the authenticity of the samples and to ensure that the protocol was followed by the participants. 4 refs, 1 fig., 3 tabs

  12. Dynamics of radionuclide exchange in the calcareous algae Halimeda at Enewetak Atoll

    Energy Technology Data Exchange (ETDEWEB)

    Spies, R.B.; Marsh, K.V.; Kercher, J.R.

    1981-01-01

    Measurements of /sup 239+240/Pu in the detrital inclusions and in acid-soluble and acid-insoluble fractions of Halimeda macrophysa showed a 10-fold higher concentration in the acid-insoluble coenocytic filaments than in the acid-soluble fraction. In a depuration experiment with Halimeda incrassata at Enewetak Atoll the loss rate of six radionuclides was measured. Data for /sup 60/Co, /sup 137/Cs, and /sup 102m/Rh were fit to loss curves by using one term for exponential loss; data for /sup 155/Eu, /sup 239+240/Pu, and /sup 241/Am required two terms. For each radionuclide, compartment size and transfer functions were determined for the appropriate one- and two-compartment models. Of 26 possible two-compartment models, only seven gave solutions with our data. Nearly identical loss rates were obtained for /sup 155/Eu, /sup 239+240/Pu, and /sup 241/Am in the fast-exchanging compartments for all seven models. The uptake rates for these nuclides were also similar when uptake rates were normalized to local sediment concentrations. The fast-exchanging compartment probably corresponds to the mucilage surface layer of the coenocytic filaments. The identity of the slow-exchanging compartment is less certain but it may correspond to the skeletal surface.

  13. Dynamics of radionuclide exchange in the calcareous algae Halimeda at Enewetak Atoll

    Energy Technology Data Exchange (ETDEWEB)

    Spies, R.B. (Lawrence Livermore Lab., CA); Marsh, K.V.; Kercher, J.R.

    1981-01-01

    Measurements of /sup 239 +240/Pu in the detrital inclusions and in acid-soluble and acid-insoluble fractions of Halimeda macrophysa showed a 10-fold higher concentration in the acid-insoluble coenocytic filaments than in the acid-soluble fraction. In a depuration experiment with Halimeda incrassata at Enewetak Atoll the loss rate of six radionuclides was measured. Data for /sup 60/Co, /sup 137/Cs, and /sup 102//sup m/Rh were fit to loss curves by using one term for exponential loss; data for /sup 155/Eu, /sup 239 +240/Pu, and /sup 241/Am required two terms. For each radionuclide, compartment size and transfer functions were determined for the apropriate one- and two-compartment models. Of 26 possible two-compartment models, only seven gave solutions with our data. Nearly identical loss rates were obtained for /sup 155/Eu, /sup 239 +240/Pu, and /sup 241/Am in the fast-exchanging compartments for all seven models. The uptake rates for these nuclides were also similar when uptake rates were normalized to local sediment concentrations. The fast-exchanging compartment probably corresponds to the mucilage surface layer of the coenocytic filaments. The identity of the slow-exchanging compartment is less certain but it may correspond to the skeletal surface.

  14. Lipid composition of water and surface sediments in Takapoto atoll lagoon (French Polynesia)

    Science.gov (United States)

    Saliot, A.; Bouloubassi, I.; Lorre-Boireau, A.; Trichet, J.; Poupet, P.; Charpy, L.

    1994-11-01

    Dissolved, particulate and sedimentary lipid compounds were analyzed in samples collected in May 1988 at three sites in the lagoon of the closed atoll of Takapoto (Tuamotu archipelago, French Polynesia). The study provides background information dealing with water quality and the nature and concentration of lipids. Non-aromatic hydrocarbons and fatty acids were isolated from lipids and analyzed by gas chromatography/mass spectrometry. Non-aromatic hydrocarbon concentrations did not exceed 1000 ng l-1 in water, and 2300 ng g-1 in surface sediments and are among the lowest encountered in pristine marine environments. No noticeable petroleum pollution was evidenced in the lagoon. Nevertheless, traces of petroleum-derived compounds were detected at the central site for both surface and deep water. Total fatty acid concentrations varied in the range 6.3 14.4 μg l-1 for the particulate phase and in the range 0.5 3.2 μg l-1 for the dissolved phase. The molecular fingerprints of fatty acids and hydrocarbons evidenced a predominant algal, and to a lesser extent microbial, origin of the organic matter present in water and sediments. Mono- and polyunsaturated fatty acids, which are essential components for animal metabolism, were identified in noticeable amounts in suspended matter (1.8 4.6 μg l-1), and at highly variable levels in the dissolved phase (0.08 1.21 μg l-1).

  15. Whale shark economics: a valuation of wildlife tourism in South Ari Atoll, Maldives

    KAUST Repository

    Cagua, Edgar F.

    2014-08-12

    Whale sharks attract large numbers of tourists, divers and snorkelers each year to South Ari Atoll in the Republic of Maldives. Yet without information regarding the use and economic extent of the attraction, it is difficult to prioritize conservation or implement effective management plans. We used empirical recreational data and generalized mixed statistical models to conduct the first economic valuation (with direct spend as the primary proxy) of whale shark tourism in Maldives. We estimated that direct expenditures for whale shark focused tourism in the South Ari Marine Protected Area for 2012 and 2013 accounted for US$7.6 and $9.4 million respectively. These expenditures are based on an estimate of 72,000-78,000 tourists who are involved in whale shark excursions annually. That substantial amount of income to resort owners and operators, and tourism businesses in a relatively small area highlights the need to implement regulations and management that safeguard the sustainability of the industry through ensuring guest satisfaction and whale shark conservation. © 2014 Cagua et al.

  16. Local extinction of the Asian tiger mosquito (Aedes albopictus) following rat eradication on Palmyra Atol

    Science.gov (United States)

    Lafferty, Kevin D.; McLaughlin, John P.; Gruner, Daniel S.; Bogar, Taylor A.; Bui, An; Childress, Jasmine N.; Espinoza, Magaly; Forbes, Elizabeth S.; Johnston, Cora A.; Klope, Maggie; Kuile, Ana Miller-ter; Lee, Michelle; Plummer, Katherine A.; Weber, David A.; Young, Ronald T.; Young, Hillary S.

    2018-01-01

    The Asian tiger mosquito, Aedes albopictus, appears to have been extirpated from Palmyra Atoll following rat eradication. Anecdotal biting reports, collection records, and regular captures in black-light traps showed the species was present before rat eradication. Since then, there have been no biting reports and no captures over 2 years of extensive trapping (black-light and scent traps). By contrast, the southern house mosquito, Culex quinquefasciatus, was abundant before and after rat eradication. We hypothesize that mammals were a substantial and preferred blood meal for Aedes, whereas Culex feeds mostly on seabirds. Therefore, after rat eradication, humans and seabirds alone could not support positive population growth or maintenance of Aedes. This seems to be the first documented accidental secondary extinction of a mosquito. Furthermore, it suggests that preferred host abundance can limit mosquito populations, opening new directions for controlling important disease vectors that depend on introduced species like rats.

  17. ''Numerical simulation of passive tracer dispersion in the pacific ocean from Mururoa atoll (French Polynesia)''

    International Nuclear Information System (INIS)

    Rancher, J.; Lazar, A.; Maes, Ch.

    1996-12-01

    In order to evaluate, on a Tropical South Pacific scale over 10 years, the consequences of an hypothetic radionuclide releases to the ocean from French Nuclear test sites, a series of numerical simulations was carried out. Tracer advection and diffusion terms were computed by a dispersion model without taking into account radioactive decay and biological interactions. Ocean dynamics and turbulent mixing coefficients were derived from a Ocean General circulation Model using annual average climatological fields. A punctual release with unit activity concentration throughout the depth showed the existence of two major directions of propagation from Mururoa atoll: one toward the Eastern Pacific when releases originated from 100-150 meters or less, and the other Westward if release depth is greater. The maximum concentrations which may possibly reach the continental South Pacific coastline originated from released points located in the 350 meters depth zone. Another experiment showed that an punctual release yields higher concentrations than the continuous release of an equivalent quantity over 10 years; two punctual releases were carried out at the characteristic depth of 5 m and 364 m: maximum concentrations decrease by factors of 10 000 and 1000 over ten years. A comparison is made with the surface release study of Ribbe and Tomczak (1990), despite a significant discrepancy in propagation direction, the order of magnitude for concentrations is comparable. (author)

  18. Sedimentary facies and Holocene depositional processes of Laura Island, Majuro Atoll

    Science.gov (United States)

    Yasukochi, Toru; Kayanne, Hajime; Yamaguchi, Toru; Yamano, Hiroya

    2014-10-01

    The depositional processes that formed Laura Island, Majuro Atoll, Marshall Islands, were reconstructed based on a facies analysis of island sediments and spine ratios, and radiocarbon ages of foraminifera. Sedimentary facies were analyzed from trenches and drill cores excavated on the island and its adjacent reef flat. Depositional ages were obtained using benthic foraminifera (Calcarina) whose spines had not been abraded. The facies were classified into two types: gravelly and sandy. The initial sediments of these sites consisted of gravelly facies in the lower horizon and sandy facies in the upper horizon. Their ages were approximately 2000 cal BP and coincident with the onset of a 1.1-m decline in regional relative sea level, which enabled deposition of the gravelly facies. Half of the sand fraction of the sediment was composed of larger benthic foraminifera. The spine ratio showed that their supply source on the reef flat was located oceanside of the island. The supply source appears to have been caused by the relative sea-level fall. This indicates that the studied island was formed by a relative reduction in wave energy and enhanced foraminiferal supply, both of which were triggered by the late Holocene relative sea-level fall.

  19. Independent verification of plutonium decontamination on Johnston Atoll (1992--1996)

    International Nuclear Information System (INIS)

    Wilson-Nichols, M.J.; Wilson, J.E.; McDowell-Boyer, L.M.; Davidson, J.R.; Egidi, P.V.; Coleman, R.L.

    1998-05-01

    The Field Command, Defense Special Weapons Agency (FCDSWA) (formerly FCDNA) contracted Oak Ridge National Laboratory (ORNL) Environmental Technology Section (ETS) to conduct an independent verification (IV) of the Johnston Atoll (JA) Plutonium Decontamination Project by an interagency agreement with the US Department of Energy in 1992. The main island is contaminated with the transuranic elements plutonium and americium, and soil decontamination activities have been ongoing since 1984. FCDSWA has selected a remedy that employs a system of sorting contaminated particles from the coral/soil matrix, allowing uncontaminated soil to be reused. The objective of IV is to evaluate the effectiveness of remedial action. The IV contractor's task is to determine whether the remedial action contractor has effectively reduced contamination to levels within established criteria and whether the supporting documentation describing the remedial action is adequate. ORNL conducted four interrelated tasks from 1992 through 1996 to accomplish the IV mission. This document is a compilation and summary of those activities, in addition to a comprehensive review of the history of the project

  20. Ages of subsurface stratigraphic intervals in the Quaternary of Enewetak Atoll, Marshall Islands

    Science.gov (United States)

    Szabo, B. J.; Tracey, J.I.; Goter, E.R.

    1985-01-01

    Drill cores of Enewetak Atoll, Marshall Islands, reveal six stratigraphic intervals, numbered in downward sequence, which represent vertical coral growth during Quaternary interglaciations. Radiocarbon dates indicate that the Holocene sea transgressed the emergent reef platform by about 8000 yr B.P. The reef grew rapidly upward (about 5 to 10 mm/yr) until about 6500 yr B.P. Afterward vertical growth slowed to about 0.5 mm/yr, then lateral development became dominant during the last several thousand years. The second interval is dated at 131,000 ?? 3000 yr B.P. by uranium series. This unit correlates with oxygen-isotope substage 5e and with terrace VIIa of Huon Peninsula, New Guinea, and of Main Reef-2 terrace at Atauro Island. The third interval is not dated because corals were recrystallized and it is tentatively correlated with either oxygen-isotope stages 7 or 9. The age of the fourth interval is estimated at 454,000 ?? 100,000 yr B.P. from measured 234U 238U activity ratios. This unit is correlated with either oxygen-isotope stage 9, 11, or 13. ?? 1985.

  1. Radiation-induced risk of resettling Bikini atoll. Final report, November 7, 1981-May 28, 1982

    International Nuclear Information System (INIS)

    Kohn, H.I.; Dreyer, N.A.

    1982-01-01

    The Department of Energy (DOE) has concluded that the Bikini atoll is unsafe for resettlement. In response to the Bikinians' request for an independent review, we have examined the following DOE findings: (a) radionuclide contamination of Eneu and Bikini Islands, (b) radiation dosage to those who might resettle the islands, and (c) risks to the health of such settlers. We are in practical agreement with the DOE estimates. Resettlement of either island in 1983 would lead to a range of annual or 30-year cumulative doses that exceed the Federal Radiation Council (FRC) guides for the general population, but not those for occupation exposure. By 2013 resettlement of Eneu probably would be permissible. The principal source of radiation dose is local food, especially coconut, owing to contamination of the soil by cesium-137. A precise estimate of dose is impossible. The availability of imported foods would lessen local food consumption, but not sufficiently to meet the FRC guides for the general population. The 30-year cumulative index dose is 61 (25-122) rem for Bikini, and about 8 (3-16) rem for Eneu

  2. Derivation of plant-soil relationships for dose assessment on Bikini Atoll

    International Nuclear Information System (INIS)

    Colsher, C.S.

    1976-11-01

    A radiological survey of the terrestrial environment of Bikini and Eneu Islands (Bikini Atoll) was conducted in June 1975 to evaluate the potential radiation dose to the returning Bikini population. This report presents measurements of the radionuclide concentration in soil profiles and in dominant species of edible and nonedible indicator plants and describes the use of these data to derive relationships to predict the plant uptake of radionuclides from soil. Soil-plant concentration factors together with leaf-leaf and fruit-leaf concentration ratios for indicator and edible plant species from the same area are calculated to quantitatively assess and compare the uptake of 90 Sr, 137 Cs, and 239 ' 240 Pu. In general, the concentration factors for 137 Cs in terrestrial vegetation are greater than those for 90 Sr and the concentration factors for both these nuclides exceed those for 239 ' 240 Pu by ten to one hundred-fold. Uptake of 90 Sr and 239 ' 240 Pu by fruit is less than that by mature leaves; however, the opposite is true for 137 Cs. The relative contribution of the individual plant species to the internal dose to man varies with the nuclide. The use of concentration factors and concentration ratios to predict nuclide concentrations in fruit from those in soil or leaves is prescribed

  3. Sediment studies at Bikini Atoll part 2. inventories of transuranium elements in surface sediments

    Energy Technology Data Exchange (ETDEWEB)

    Noshkin, V.E.; Eagle, R.J.; Wong, K.M.; Robison, W.L.

    1997-10-01

    This is the second of three reports on Bikini sediment studies, which discusses the concentrations and inventories of {sup 241}Am and {sup 239+240}Pu in sediments from the lagoon. Surface sediment samples were collected from 87 locations over the entire lagoon at Bikini Atoll during 1979. The collections were made to map the distribution of long-lived radionuclides associated with the bottom material and to show what modifications occurred in the composition of the sediment as a result of the testing program. Present inventories for {sup 241}Am and {sup 239+240}Pu in the surface 2 cm of sediment are estimated to be 14 and 17 TBq, respectively. These values are estimated to represent only 14% of the total inventory in the sediment column. Sediment inventories of {sup 239+240}Pu and {sup 241}Am are changing only slowly with time through chemical- physical processes that continuously mobilize small amounts of the transuranics to the water column. The lowest concentrations and inventories are associated with deposits logoonward of the eastern reef.

  4. Sediment studies at Bikini Atoll part 1. distribution of fine and coarse components in surface sediments

    Energy Technology Data Exchange (ETDEWEB)

    Noshkin, V. E.; Eagle, R.J.; Robison, W.L.

    1997-01-01

    In 1979, 21 years after the moratorium on nuclear testing in the Marshall Islands, surface sediment samples (to depths of 2 and 4 cm) were collected from 87 locations over the floor of Bikini lagoon. The main purpose for the collections was to map the distribution of long- lived man-made radionuclides associated with the bottom material. In addition the samples were processed to estimate the fraction of fine and coarse components to show what modifications occurred since the sediment composition was first described in samples collected before testing in 1946. In this report a comparison is made of the amount and distribution of fine material associated with the lagoon surface sediment before and after the testing of nuclear devices. Nuclear testing produced more finely divided material in-the surface sediment layer over large areas of the lagoon and especially in regions of the lagoon and reef adjacent to test sites. Five cratering events at Bikini Atoll generated sufficient material to account for the inventory of new fine material found over the bottom surface of the lagoon. Although the fraction of fine material in the bottom sediments was altered by the nuclear events, the combined processes of formation, transport and deposition were not sufficiently dynamic to alter the geographical features of the major sedimentary components over most of the lagoon floor.

  5. SAR Observation and Numerical Simulation of Internal Solitary Wave Refraction and Reconnection Behind the Dongsha Atoll

    Science.gov (United States)

    Jia, T.; Liang, J. J.; Li, X.-M.; Sha, J.

    2018-01-01

    The refraction and reconnection of internal solitary waves (ISWs) around the Dongsha Atoll (DSA) in the northern South China Sea (SCS) are investigated based on spaceborne synthetic aperture radar (SAR) observations and numerical simulations. In general, a long ISW front propagating from the deep basin of the northern SCS splits into northern and southern branches when it passes the DSA. In this study, the statistics of Envisat Advanced SAR (ASAR) images show that the northern and southern wave branches can reconnect behind the DSA, but the reconnection location varies. A previously developed nonlinear refraction model is set up to simulate the refraction and reconnection of the ISWs behind the DSA, and the model is used to evaluate the effects of ocean stratification, background currents, and incoming ISW characteristics at the DSA on the variation in reconnection locations. The results of the first realistic simulation agree with consecutive TerraSAR-X (TSX) images captured within 12 h of each other. Further sensitivity simulations show that ocean stratification, background currents, and initial wave amplitudes all affect the phase speeds of wave branches and therefore shift their reconnection locations while shapes and locations of incoming wave branches upstream of the DSA profoundly influence the subsequent propagation paths. This study clarifies the variation in reconnection locations of ISWs downstream of the DSA and reveals the important mechanisms governing the reconnection process, which can improve our understanding of the propagation of ISWs near the DSA.

  6. Environmental protection

    International Nuclear Information System (INIS)

    Hull, A.P.

    1979-01-01

    Environmental Studies and Internal Dosimetry projects include: Environmental Protection; 1977 Environmental Monitoring Report; Sewage Sludge Disposal on the Sanitary Landfill; Radiological Analyses of Marshall Islands Environmental Samples, 1974 to 1976; External Radiation Survey and Dose Predictions for Rongelap, Utirik, Rongerik, Ailuk, and Wotje Atolls; Marshall Islands - Diet and Life Style Study; Dose Reassessment for Populations on Rongelap and Utirik Following Exposure to Fallout from BRAVO Incident (March 1, 1954); Whole Body Counting Results from 1974 to 1979 for Bikini Island Residents; Dietary Radioactivity Intake from Bioassay Data, a Model Applied to 137 Cs Intake by Bikini Island Residents; and External Exposure Measurements at Bikini Atoll

  7. Larval dispersal modeling of pearl oyster Pinctada margaritifera following realistic environmental and biological forcing in Ahe atoll lagoon.

    Directory of Open Access Journals (Sweden)

    Yoann Thomas

    Full Text Available Studying the larval dispersal of bottom-dwelling species is necessary to understand their population dynamics and optimize their management. The black-lip pearl oyster (Pinctada margaritifera is cultured extensively to produce black pearls, especially in French Polynesia's atoll lagoons. This aquaculture relies on spat collection, a process that can be optimized by understanding which factors influence larval dispersal. Here, we investigate the sensitivity of P. margaritifera larval dispersal kernel to both physical and biological factors in the lagoon of Ahe atoll. Specifically, using a validated 3D larval dispersal model, the variability of lagoon-scale connectivity is investigated against wind forcing, depth and location of larval release, destination location, vertical swimming behavior and pelagic larval duration (PLD factors. The potential connectivity was spatially weighted according to both the natural and cultivated broodstock densities to provide a realistic view of connectivity. We found that the mean pattern of potential connectivity was driven by the southwest and northeast main barotropic circulation structures, with high retention levels in both. Destination locations, spawning sites and PLD were the main drivers of potential connectivity, explaining respectively 26%, 59% and 5% of the variance. Differences between potential and realistic connectivity showed the significant contribution of the pearl oyster broodstock location to its own dynamics. Realistic connectivity showed larger larval supply in the western destination locations, which are preferentially used by farmers for spat collection. In addition, larval supply in the same sectors was enhanced during summer wind conditions. These results provide new cues to understanding the dynamics of bottom-dwelling populations in atoll lagoons, and show how to take advantage of numerical models for pearl oyster management.

  8. Invisible Nuclear Catastrophe Consequences of the U.S. Atomic and Hydrogen Bomb Testings in the Marshall Islands: Focusing on the “Overlooked” Ailuk Atoll

    OpenAIRE

    Takemine, Seiichiro

    2018-01-01

    The United States conducted sixty-seven nuclear tests in total at Bikini and Enewetak Atoll in the Marshall Islands between 1946 and 1958. T his article discusses the U.S. nuclear test issues in the Marshall Islands, focusing on the local people who have not been able t o apply for the U.S. compensation, especially those on Ailuk Atoll. Until today, little attention has been given to these areas.Interviews with survivors as well as declassified U.S. documents make it clear that the nuclear te...

  9. Colonization and growth of crustose coralline algae (Corallinales, Rhodophyta on the Rocas Atoll

    Directory of Open Access Journals (Sweden)

    Alexandre Bigio Villas Bôas

    2005-12-01

    Full Text Available Crustose coralline algae play a fundamental role in reef construction all over the world. The aims fo this study were to identify and estimate the abundance of the dominant crustose coralline algae in shallow reef habitats, measuring their colonization, growth rates and productivity. Crusts sampled from different habitats were collected on leeward and windward reefs. Discs made of epoxy putty were fixed on the reef surface to follow coralline colonization and discs containing the dominant coralline algae were fixed on different habitats to measure the crusts' marginal growth. The primary production experiments followed the clear and dark bottle method for dissolved oxygen reading. Porolithon pachydermum was confirmed as the dominant crustose coralline alga on the Rocas Atoll. The non-cryptic flat form of P. pachydermum showed a faster growth rate on the leeward than on the windward reef. This form also had a faster growth rate on the reef crest (0.05 mm.day-1 than on the reef flat (0.01 mm.day-1. The cryptic protuberant form showed a trend, though not significant, towards a faster growth rate on the reef crest and in tidal pools than on the reef flat. Colonization was, in general, very slow as compared to that presented by other reef studies. P. pachydermum was a productive crust both in non-cryptic and cryptic habitats.As algas calcárias incrustantes exercem um papel fundamental na construção de recifes ao redor do mundo. Neste trabalho os objetivos foram: identificar e estimar a abundância da alga calcária incrustante dominante nas partes rasas do recife, verificando suas taxas de colonização, crescimento e produtividade. Crostas de diferentes habitats foram estudadas em locais a barlavento e sotavento. Discos feitos com massa epóxi foram fixados na superfície do recife para acompanhar a colonização das algas calcárias e discos contendo a alga calcária dominante foram fixados em diferentes habitats para medir o crescimento de suas

  10. A dose assessment for a U.S. nuclear test site -- Bikini Atoll

    International Nuclear Information System (INIS)

    Robison, W.L.; Bogen, K.T.; Conrado, C.L.

    1993-07-01

    On March 1, 1954, a nuclear weapon test, code-named BRAVO, conducted at Bikini Atoll in the northern Marshall Islands contaminated the major residence island. Here the authors provide a radiological dose assessment for the main residence island, Bikini, using extensive radionuclide concentration data derived from analysis of food crops, ground water, cistern water, fish and other marine species, animals, air, and soil collected at Bikini Island. The unique composition of coral soil greatly alters the relative contribution of cesium-137 and strontium-90 to the total estimated dose relative to expectations based on North American and European soils. Cesium-137 produces 96% of the estimated dose for returning residents, mostly through uptake from the soil to terrestrial food crops but also from external gamma exposure. The estimated maximum annual effective dose is 4.4 mSv y -1 when imported foods, which are now an established part of the diet, are available. The 30-, 50-, and 70-y integral effective doses are 10 cSv, 14 cSv, and 16 cSv, respectively. An analysis of interindividual variability in 0- to 30-y expected integral dose indicates that 95% of Bikini residents would have expected doses within a factor of 3.4 above and 4.8 below the population-average value. A corresponding uncertainty analysis showed that after about 5 y of residence, the 95% confidence limits on population-average dose would be ±35% of its expected value. The authors have evaluated various countermeasures to reduce 137 Cs in food crops. Treatment with potassium reduces the uptake of 137 Cs into food crops, and therefore the ingestion dose, to less than 10% of pretreatment levels and has essentially no negative environmental consequences

  11. Uncertainty analysis for an updated dose assessment for a US nuclear test site: Bikini Atoll

    International Nuclear Information System (INIS)

    Bogen, K.T.; Conrado, C.L.; Robison, W.L.

    1995-11-01

    A detailed analysis of uncertainty and interindividual variability in estimated doses was conducted for a rehabilitation scenario for Bikini Island at Bikini Atoll, in which the top 40 cm of soil would be removed in the housing and village area, and the rest of the island is treated with potassium fertilizer, prior to an assumed resettlement date of 1999. Predicted doses were considered for the following fallout-related exposure pathways: ingested Cesium-137 and Strontium-90, external gamma exposure, and inhalation and ingestion of Americium-241 + Plutonium-239+240. Two dietary scenarios were considered: (1) imported foods are available (IA), and (2) imported foods are unavailable (only local foods are consumed) (IUA). Corresponding calculations of uncertainty in estimated population-average dose showed that after ∼5 y of residence on Bikini, the upper and lower 95% confidence limits with respect to uncertainty in this dose are estimated to be approximately 2-fold higher and lower than its population-average value, respectively (under both IA and IUA assumptions). Corresponding calculations of interindividual variability in the expected value of dose with respect to uncertainty showed that after ∼5 y of residence on Bikini, the upper and lower 95% confidence limits with respect to interindividual variability in this dose are estimated to be approximately 2-fold higher and lower than its expected value, respectively (under both IA and IUA assumptions). For reference, the expected values of population-average dose at age 70 were estimated to be 1.6 and 5.2 cSv under the IA and IUA dietary assumptions, respectively. Assuming that 200 Bikini resettlers would be exposed to local foods (under both IA and IUA assumptions), the maximum 1-y dose received by any Bikini resident is most likely to be approximately 2 and 8 mSv under the IA and IUA assumptions, respectively

  12. Atoll groundwater movement and its response to climatic and sea-level fluctuations

    Science.gov (United States)

    Oberle, Ferdinand; Swarzenski, Peter W.; Storlazzi, Curt

    2017-01-01

    Groundwater resources of low-lying atoll islands are threatened due to short-term and long-term changes in rainfall, wave climate, and sea level. A better understanding of how these forcings affect the limited groundwater resources was explored on Roi-Namur in the Republic of the Marshall Islands. As part of a 16-month study, a rarely recorded island-overwash event occurred and the island’s aquifer’s response was measured. The findings suggest that small-scale overwash events cause an increase in salinity of the freshwater lens that returns to pre-overwash conditions within one month. The overwash event is addressed in the context of climate-related local sea-level change, which suggests that overwash events and associated degradations in freshwater resources are likely to increase in severity in the future due to projected rises in sea level. Other forcings, such as severe rainfall events, were shown to have caused a sudden freshening of the aquifer, with salinity levels retuning to pre-rainfall levels within three months. Tidal forcing of the freshwater lens was observed in electrical resistivity profiles, high-resolution conductivity, groundwater-level well measurements and through submarine groundwater discharge calculations. Depth-specific geochemical pore water measurements further assessed and confirmed the distinct boundaries between fresh and saline water masses in the aquifer. The identification of the freshwater lens’ saline boundaries is essential for a quantitative evaluation of the aquifers freshwater resources and help understand how these resources may be impacted by climate change and anthropogenic activities.

  13. Atoll Groundwater Movement and Its Response to Climatic and Sea-Level Fluctuations

    Directory of Open Access Journals (Sweden)

    Ferdinand K. J. Oberle

    2017-08-01

    Full Text Available Groundwater resources of low-lying atoll islands are threatened due to short-term and long-term changes in rainfall, wave climate, and sea level. A better understanding of how these forcings affect the limited groundwater resources was explored on Roi-Namur in the Republic of the Marshall Islands. As part of a 16-month study, a rarely recorded island-overwash event occurred and the island’s aquifer’s response was measured. The findings suggest that small-scale overwash events cause an increase in salinity of the freshwater lens that returns to pre-overwash conditions within one month. The overwash event is addressed in the context of climate-related local sea-level change, which suggests that overwash events and associated degradations in freshwater resources are likely to increase in severity in the future due to projected rises in sea level. Other forcings, such as severe rainfall events, were shown to have caused a sudden freshening of the aquifer, with salinity levels retuning to pre-rainfall levels within three months. Tidal forcing of the freshwater lens was observed in electrical resistivity profiles, high-resolution conductivity, groundwater-level well measurements and through submarine groundwater discharge calculations. Depth-specific geochemical pore water measurements further assessed and confirmed the distinct boundaries between fresh and saline water masses in the aquifer. The identification of the freshwater lens’ saline boundaries is essential for a quantitative evaluation of the aquifers freshwater resources and help understand how these resources may be impacted by climate change and anthropogenic activities.

  14. Genetic diversity of Wolbachia endosymbionts in Culex quinquefasciatus from Hawai`i, Midway Atoll, and Samoa

    Science.gov (United States)

    Atkinson, Carter T.; Watcher-Weatherwax, William; Lapointe, Dennis

    2016-01-01

    Incompatible insect techniques are potential methods for controlling Culex quinquefasciatus and avian disease transmission in Hawai‘i without the use of pesticides or genetically modified organisms. The approach is based on naturally occurring sperm-egg incompatibilities within the Culex pipiens complex that are controlled by different strains of the bacterial endosymbiont Wolbachia pipientis (wPip). Incompatibilities can be unidirectional (crosses between males infected with strain A and females infected with strain B are fertile, while reciprocal crosses are not) or bidirectional (reciprocal crosses between sexes with different wPip strains are infertile). The technique depends on release of sufficient numbers of male mosquitoes infected with an incompatible wPip strain to suppress mosquito populations and reduce transmission of introduced avian malaria (Plasmodium relictum) and Avipoxvirus in native forest bird habitats. Both diseases are difficult to manage using more traditional methods based on removal and treatment of larval habitats and coordination of multiple approaches may be needed to control this vector. We characterized the diversity of Wolbachia strains in C. quinquefasciatus from Hawai‘i, Kaua‘i, Midway Atoll, and American Samoa with a variety of genetic markers to identify compatibility groups and their distribution within and between islands. We confirmed the presence of wPip with multilocus sequence typing, tested for local genetic variability using 16 WO prophage genes, and identified similarities to strains from other parts of the world with a transposable element (tr1). We also tested for genetic differences in ankyrin motifs (ank2 and pk1) which have been used to classify wPip strains into five worldwide groups (wPip1–wPip5) that vary in compatibility with each other based on experimental crosses. We found a mixture of both widely distributed and site specific genotypes based on presence or absence of WO prophage and transposable

  15. Semantically Enhanced Recommender Systems

    Science.gov (United States)

    Ruiz-Montiel, Manuela; Aldana-Montes, José F.

    Recommender Systems have become a significant area in the context of web personalization, given the large amount of available data. Ontologies can be widely taken advantage of in recommender systems, since they provide a means of classifying and discovering of new information about the items to recommend, about user profiles and even about their context. We have developed a semantically enhanced recommender system based on this kind of ontologies. In this paper we present a description of the proposed system.

  16. Trust for intelligent recommendation

    CERN Document Server

    Bhuiyan, Touhid

    2013-01-01

    Recommender systems are one of the recent inventions to deal with the ever-growing information overload in relation to the selection of goods and services in a global economy. Collaborative Filtering (CF) is one of the most popular techniques in recommender systems. The CF recommends items to a target user based on the preferences of a set of similar users known as the neighbors, generated from a database made up of the preferences of past users. In the absence of these ratings, trust between the users could be used to choose the neighbor for recommendation making. Better recommendations can b

  17. Plastic ingestion by Masked booby, Sula dactylatra Lesson, 1831, on Biological Reserve of Rocas Atoll, RN, Brazil

    Directory of Open Access Journals (Sweden)

    Erich de Freitas Mariano

    2012-11-01

    Full Text Available Plastic particles are one of the most common pollutants in the marine environment and it is reaching regions with low human population density. These particles are frequently ingested by many marine organisms, causing digestive problems, which may lead to the weakening and death of the animal. In a research on the feeding of 631-masked boobies, Sula dactylatra from the Biological Reserve of Atol das Rocas, plastic particles were found in stomach contents of four adults. The artifacts found were made of transperant plastic, a piece of label of a mineral water bottle, two pieces of black plastic and a small hard and red piece. The flow of fishing and tourism boats on the Atol das Rocas Biological Reserve may be the source of origin of the plastic parts in both the stomach contents and those found on the islands of the reserve, which suggests that anthropogenic behaviour has already reached isolated areas which should have a high degree of biodiversity protection. Several measures can be taken to avoid deleterious events in the marine biota, but there is great difficulty in avoiding waste dumping from fishing and tourism ships/boats, in addition to that, there are many materials from the mainland, which requires an increase in awareness and supervision.

  18. Distribution, sources and risk assessment of polychlorinated biphenyls in soils from the Midway Atoll, North Pacific Ocean.

    Directory of Open Access Journals (Sweden)

    Jing Ge

    Full Text Available Concentrations of 28 polychlorinated biphenyls (PCBs were assessed in soils from the Midway Atoll in the central North Pacific Ocean. The analytical procedure involved the application of accelerated solvent extraction (ASE and gas chromatography coupled with ion trap mass spectrometric detection (GC/ITMS for identification and quantification. Among the 28 PCB congeners studied, 26 of them, except CB195 and CB209, were detected in the analyzed samples at different frequencies. The total concentrations of 28 indicator PCBs (ΣPCBs ranged from 2.6 to 148.8 ng g⁻¹ with an average value of 50.7 ng g⁻¹ and median of 39.5 ng g⁻¹. Sources and congeners' pattern of PCB were investigated in the soil of Midway Atoll. The principal component analysis indicated that the compositions of PCBs in most of the soil samples were similar. The total concentrations of PCBs were used to assess the cancer risk probabilities in humans via ingestion, dermal contact and inhalation of soil particles. Very low cancer risk was found in all soil samples caused by ΣPCBs.

  19. The natural history of Caroline Atoll, Southern Line Islands. Part I. History, physiography, botany, and isle descriptions

    Science.gov (United States)

    Kepler, A.K.; Kepler, C.B.

    1994-01-01

    conclusion: Lushly wooded Caroline Atoll, with the majority of its 39 islets (399 ha of land) either in near-pristine condition or having recovered remarkably from past disturbance, is one of the least spoiled atolls in the Pacific. Uninhabited, it harbors plant ecosystems and breeding seabirds (Pt. II) of national and international importance. Its marine and terrestrial ecosystems are prime outdoor ecological laboratories for research on geological processes including ground water, sea level changes, the dynamics of motu formation, fish poisoning, and numerous facets of ecology including plant succession and Pisonia growth rates. Caroline boasts prime coral reefs thickly studded with Tridacna clams, substantial numbers of coconut crabs, breeding sites for green turtles, wintering grounds for shorebirds including the rare Bristle-thighed Curlew, ancient Tuamotuan marae, and a crystalline, unpolluted lagoon. The variety, abundance, and quality of its flora and fauna qualify it for status as an officially recognized international preserve (Pt. II, Sect. G). Efforts toward its conservation have thus far been unsuccessful: in 1992 it was leased to a private French businessman who is currently fishing the reefs for commercial profit, as well as disturbing seabird, turtle and coconut crab populations.

  20. Spectral evolution of the Atoll source 4U 1728-34 with RXTE and INTEGRAL: evidence for hard X-ray tail

    NARCIS (Netherlands)

    Tarana, A.; Belloni, T.; Bazzano, A.; Homan, J.; Méndez, M.; Ubertini, P.; Comastri, A.; Angelini, L.; Cappi, M.

    We report the temporal and spectral results on the INTEGRAL and RXTE 2006-2007 observation campaign of the Atoll source 4U 1728-34 (GX 354-0). The source shows, more than once, spectral evolution as revealed by the hardness intensity diagram. The soft state is well described by a Comptonization with

  1. Frequency distribution, isotopic composition and physical characterization of plutonium-bearing particles from the Fig-Quince zone on Runit Island, Enewetak Atoll

    DEFF Research Database (Denmark)

    Hamilton, Terry F.; Jernström, Jussi; Martinelli, Roger E.

    2009-01-01

    Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946–58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area...

  2. Most atolls will be uninhabitable by the mid-21st century because of sea-level rise exacerbating wave-driven flooding

    Science.gov (United States)

    Storlazzi, Curt; Gingerich, Stephen B.; van Dongeren, Ap; Cheriton, Olivia; Swarzenski, Peter W.; Quataert, Ellen; Voss, Clifford I.; Field, Donald W.; Annamalai, Hariharasubramanian; Piniak, Greg A.; McCall, Robert T.

    2018-01-01

    Sea levels are rising, with the highest rates in the tropics, where thousands of low-lying coral atoll islands are located. Most studies on the resilience of these islands to sea-level rise have projected that they will experience minimal inundation impacts until at least the end of the 21st century. However, these have not taken into account the additional hazard of wave-driven overwash or its impact on freshwater availability. We project the impact of sea-level rise and wave-driven flooding on atoll infrastructure and freshwater availability under a variety of climate change scenarios. We show that, on the basis of current greenhouse gas emission rates, the nonlinear interactions between sea-level rise and wave dynamics over reefs will lead to the annual wave-driven overwash of most atoll islands by the mid-21st century. This annual flooding will result in the islands becoming uninhabitable because of frequent damage to infrastructure and the inability of their freshwater aquifers to recover between overwash events. This study provides critical information for understanding the timing and magnitude of climate change impacts on atoll islands that will result in significant, unavoidable geopolitical issues if it becomes necessary to abandon and relocate low-lying island states.

  3. An updated dose assesment for resettlement options at Bikini atoll - A US nuclear test site

    International Nuclear Information System (INIS)

    Robison, W.L.; Bogen, K.T.; Conrado, C.L.

    1997-01-01

    There has been a continuing effort since 1977 to refine dose assessments for resettlement options at Bikini Atoll. Here we provide a radiological dose assessment for the main residence island, Bikini, using extensive radio nuclide concentration data derived from analysis of food crops, ground water, cistern water, fish and other marine species, animals, air, and soil collected at Bikini Island as part of our continuing research and monitoring program that began in 1978. The unique composition of coral soil greatly alters the relative contribution of 137 Cs and 90 Sr to the total estimated dose relative to expectations based on North American and European soils. Without counter measures, 137 Cs produces 96% of the estimated dose for returning residents, mostly through uptake from the soil to terrestrial food crops but also from external gamma exposure. The doses are calculated assuming a resettlement date of 1999. The estimated maximum annual effective dose for current island conditions is 4.0 mSv when imported foods, which are now an established part of the diet, are available. The 30-, 50-, and 70-y integral effective doses are 91 mSv, 130 mSv, and 150 mSv, respectively. A detailed uncertainty analysis for these dose estimates is presented in a companion paper in this issue. We have evaluated various countermeasures to reduce 137 Cs in food crops. Treatment with potassium reduces the uptake of 137 Cs into food crops, and therefore the ingestion dose, to about 5 % of pretreatment levels and has essentially no negative environmental consequences. We have calculated the dose for the rehabilitation scenario where the top 40 cm of soil is removed in the housing and village area, and the rest of the island is treated with potassium fertilizer; the maximum annual effective dose is 0.41 mSv and the 30-, 50-, and 70-y integral effective doses are 9.8 mSv, 14 mSv, and 16 mSv, respectively. 44 refs., 3 figs., 11 tabs

  4. Spatial distribution of organochlorine contaminants in soil, sediment, and fish in Bikini and Enewetak Atolls of the Marshall Islands, Pacific Ocean.

    Science.gov (United States)

    Wang, Jun; Caccamise, Sarah A L; Wu, Liejun; Woodward, Lee Ann; Li, Qing X

    2011-08-01

    Several nuclear tests were performed at Enewetak and Bikini Atolls in the Marshall Islands between 1946 and 1958. The events at Bikini Atoll involved several ships that were tested for durability during nuclear explosions, and 24 vessels now rest on the bottom of the Bikini lagoon. Nine soil samples were collected from different areas on the two islands of the atoll, and eighteen sediment, nine fish, and one lobster were collected in the vicinity of the sunken ships. Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polychlorinated terphenyls (PCTs) in these samples were analyzed using gas chromatography/ion trap mass spectrometry (GC/ITMS). The average recoveries ranged from 78% to 104% for the different PCB congeners. The limits of detection (LOD) for PCBs, PCTs, DDE, DDT, and dieldrin ranged 10-50 pg g(-1). Some fish from Enewetak contained PCBs at a concentration range of 37-137 ng g(-1), dry weight (dw), and most of the soils from Enewetak showed evidence of PCBs (22-392 ng g(-1)dw). Most of the Bikini lagoon sediment samples contained PCBs, and the highest was the one collected from around the Saratoga, an aircraft carrier (1555 ng g(-1)dw). Some of the fish samples, most of the soil samples, and only one of the sediment samples contained 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) and PCBs. In addition to PCBs, the soils from Enewetak Atoll contained PCTs. PCTs were not detected in the sediment samples from Bikini Atoll. The results suggest local pollution sources of PCBs, PCTs, and OCPs. Copyright © 2011. Published by Elsevier Ltd.

  5. Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation, January 1983-December 1984

    International Nuclear Information System (INIS)

    Adams, W.H.; Engle, J.R.; Harper, J.A.; Heotis, P.M.; Scott, W.A.

    1986-01-01

    March 1, 1984, was the 30th anniversary of the Bravo thermonuclear test that resulted in the accidental exposure of the populations of Rongelap and Utirik atolls to radioactive fallout. The chronicling of the medical events resulting from that exposure is continued in this report, which covers the period from January 1983 through December 1984. An updated listing of all relevant publications from the Medical Department Brookhaven National Laboratory, is presented in the Reference Section. Thirty years of observation continue to show no detectable increase in mortality in the exposed population as a result of that exposure. The survival curves of the high-exposure Rongelap group, the low-exposure Utirik population, and an unexposed group of Rongelap people matched by age and sex to the exposed Rongelap group in 1957 continue to be similar. 89 refs., 2 figs., 6 tabs

  6. Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation, January 1983-December 1984

    Energy Technology Data Exchange (ETDEWEB)

    Adams, W.H.; Engle, J.R.; Harper, J.A.; Heotis, P.M.; Scott, W.A.

    1986-01-01

    March 1, 1984, was the 30th anniversary of the Bravo thermonuclear test that resulted in the accidental exposure of the populations of Rongelap and Utirik atolls to radioactive fallout. The chronicling of the medical events resulting from that exposure is continued in this report, which covers the period from January 1983 through December 1984. An updated listing of all relevant publications from the Medical Department Brookhaven National Laboratory, is presented in the Reference Section. Thirty years of observation continue to show no detectable increase in mortality in the exposed population as a result of that exposure. The survival curves of the high-exposure Rongelap group, the low-exposure Utirik population, and an unexposed group of Rongelap people matched by age and sex to the exposed Rongelap group in 1957 continue to be similar. 89 refs., 2 figs., 6 tabs.

  7. OARSI Clinical Trials Recommendations

    DEFF Research Database (Denmark)

    McAlindon, T. E.; Driban, J. B.; Henrotin, Y.

    2015-01-01

    The goal of this document is to update the original OARSI recommendations specifically for the design, conduct, and reporting of clinical trials that target symptom or structure modification among individuals with knee osteoarthritis (OA). To develop recommendations for the design, conduct...

  8. Efforts to eradicate yellow crazy ants on Johnston Atoll: Results from Crazy Ant Strike Team IX, December 2014-June 2015

    Science.gov (United States)

    Banko, Paul C.; Peck, Robert W.; Donmoyer, Kevin; Kropidlowski, Stephan; Pollock, Amanda

    2015-01-01

    The ecologically destructive yellow crazy ant (YCA; Anoplolepis gracilipes) was first detected on Johnston Atoll in January 2010. Within eight months, the U.S. Fish and Wildlife Service had mobilized its first crazy ant strike team (CAST), a group of biologists dedicated to testing and identifying insecticidal baits to be used to eradicate the ant on the atoll. During December 2014‒May 2015 CAST IX focused on testing hydrogel crystals saturated with sucrose solution (25%) carrying the insecticides thiamethoxam and dinotefuran against YCA. A series of experiments, including artificial nest box trials, and field-based palatability trials and eradication tests on small (500 m2 or 0.05 ha) and large plots (2500 m2 or 0.25 ha), were conducted to test concentrations of thiamethoxam ranging from 0.0005% to 0.01%, and dinotefuran at 0.05%. Additionally, the cat food-based matrix containing dinotefuran (0.05%), the standard bait used to suppress YCA on Johnston since 2011, and textured vegetable protein (TVP) carrying dinotefuran at 0.1% and 0.05% were included in large plot tests. Nest box trials were inconclusive due to a consistent loss of queen and worker ants in control boxes, so they were discontinued. Palatability trials suggested higher dosages of thiamethoxam (0.005 and 0.01%) were less attractive than lower dosages (0.0005 and 0.001%) and controls (sucrose only), but small and large plot experiments failed to identify a thiamethoxam concentration that was consistently effective at killing YCA. In contrast, hydrogel containing dinotefuran was consistently effective, killing >95% of YCA on small and large plots. As expected, the cat food bait effectively reduced YCA abundances, but was slightly less effective than hydrogel containing dinotefuran over time. Three successive, approximately weekly treatments of large plots with hydrogel bait, or other baits followed by hydrogel bait, suggest an increasing overall effectiveness, with no aversion of YCA to the bait

  9. Preliminary hard and soft bottom seafloor substrate map (5m grid) derived from an unsupervised classification of gridded backscatter and bathymetry derivatives at Rose Atoll Lagoon, Territory of American Samoa, USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Preliminary hard and soft seafloor substrate map derived from an unsupervised classification of multibeam backscatter and bathymetry derivatives at Rose Atoll...

  10. Preliminary hard and soft bottom seafloor substrate map (40m grid) derived from an unsupervised classification of gridded backscatter and bathymetry derivatives at Rose Atoll, Territory of American Samoa, USA.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Preliminary hard and soft seafloor substrate map derived from an unsupervised classification of multibeam backscatter and bathymetry derivatives at Rose Atoll,...

  11. National Coral Reef Monitoring Program: Stratified Random Surveys (StRS) of Coral Demography (Adult and Juvenile Corals) across Rose Atoll from 2016-05-01 to 2016-05-04 (NCEI Accession 0159167)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data described here result from benthic coral demographic surveys for two life stages (juveniles, adults) across Rose Atoll in 2016. Juvenile colony surveys...

  12. Forecasting the impact of storm waves and sea-level rise on Midway Atoll and Laysan Island within the Papahānaumokuākea Marine National Monument—a comparison of passive versus dynamic inundation models

    Science.gov (United States)

    Storlazzi, Curt D.; Berkowitz, Paul; Reynolds, Michelle H.; Logan, Joshua B.

    2013-01-01

    Two inundation events in 2011 underscored the potential for elevated water levels to damage infrastructure and affect terrestrial ecosystems on the low-lying Northwestern Hawaiian Islands in the Papahānaumokuākea Marine National Monument. The goal of this study was to compare passive "bathtub" inundation models based on geographic information systems (GIS) to those that include dynamic water levels caused by wave-induced set-up and run-up for two end-member island morphologies: Midway, a classic atoll with islands on the shallow (2-8 m) atoll rim and a deep, central lagoon; and Laysan, which is characterized by a deep (20-30 m) atoll rim and an island at the center of the atoll. Vulnerability to elevated water levels was assessed using hindcast wind and wave data to drive coupled physics-based numerical wave, current, and water-level models for the atolls. The resulting model data were then used to compute run-up elevations using a parametric run-up equation under both present conditions and future sea-level-rise scenarios. In both geomorphologies, wave heights and wavelengths adjacent to the island shorelines increased more than three times and four times, respectively, with increasing values of sea-level rise, as more deep-water wave energy could propagate over the atoll rim and larger wind-driven waves could develop on the atoll. Although these increases in water depth resulted in decreased set-up along the islands’ shorelines, the larger wave heights and longer wavelengths due to sea-level rise increased the resulting wave-induced run-up. Run-up values were spatially heterogeneous and dependent on the direction of incident wave direction, bathymetry, and island configuration. Island inundation was modeled to increase substantially when wave-driven effects were included, suggesting that inundation and impacts to infrastructure and terrestrial habitats will occur at lower values of predicted sea-level rise, and thus sooner in the 21st century, than suggested

  13. Bikini Atoll Rehabilitation Committee Report no. 5 Status March 31, 1987. Submitted to the U.S. Congress, House and Senate Committees on Interior Appropriations, pursuant to House Report 99-1002 and Public Law 99-500. Department of Interior Account no. 14X0414/TT-1580X08, Washington, DC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-07-01

    The principal findings of Report No. 5, Bikini Atoll Rehabilitation Committee, March 31, 1987, are as follows: (1) Three principal methods for contamination control are under study at Bikini Atoll: removal of top soil, treatment of soil with potassium salt, and treatment by irrigation with sea water. The latter two should be cheaper and ecologically superior to excavation. All three methods have reduced the uptake of cesium-137 by coconuts and vegetables. (2) It is encouraging to report that in one sea water trial the beneficial effect has lasted for at least 1.6 years after treatment. Third-year results from the experiment should become available this year. (3) Various trials are under way to determine optimum treatment schedules (amount of agent per treatment, frequency of treatments) and the duration of the effects thereby engendered. Some schedules include more than one type of treatment. Initial results from these trials are becoming available during the present year. Until such detailed information is available and securely established, specific recommendations for a rehabilitation program should not be made. (4) It is now thought that the active agent in sea water is the sodium ion. Cation equivalency tests which take into account potassium, sodium and magnesium are under way. (5) As reported previously, Eneu may be settled now. BARC recommends that after Governmental review and possible modification, the conceptual designs now available be developed for engineering purposes to permit rehabilitation logistics and construction to get under way. (6) On the basis of the findings thus far, and making 'reasonable' assumptions about the construction costs of community facilities, BARC estimates that the total rehabilitation costs will lie in the range of $55 to $90 million. Most of the range is due to uncertainty regarding the decontamination program. (author)

  14. Bikini Atoll Rehabilitation Committee Report no. 5 Status March 31, 1987. Submitted to the U.S. Congress, House and Senate Committees on Interior Appropriations, pursuant to House Report 99-1002 and Public Law 99-500. Department of Interior Account no. 14X0414/TT-1580X08, Washington, DC

    International Nuclear Information System (INIS)

    1987-01-01

    The principal findings of Report No. 5, Bikini Atoll Rehabilitation Committee, March 31, 1987, are as follows: (1) Three principal methods for contamination control are under study at Bikini Atoll: removal of top soil, treatment of soil with potassium salt, and treatment by irrigation with sea water. The latter two should be cheaper and ecologically superior to excavation. All three methods have reduced the uptake of cesium-137 by coconuts and vegetables. (2) It is encouraging to report that in one sea water trial the beneficial effect has lasted for at least 1.6 years after treatment. Third-year results from the experiment should become available this year. (3) Various trials are under way to determine optimum treatment schedules (amount of agent per treatment, frequency of treatments) and the duration of the effects thereby engendered. Some schedules include more than one type of treatment. Initial results from these trials are becoming available during the present year. Until such detailed information is available and securely established, specific recommendations for a rehabilitation program should not be made. (4) It is now thought that the active agent in sea water is the sodium ion. Cation equivalency tests which take into account potassium, sodium and magnesium are under way. (5) As reported previously, Eneu may be settled now. BARC recommends that after Governmental review and possible modification, the conceptual designs now available be developed for engineering purposes to permit rehabilitation logistics and construction to get under way. (6) On the basis of the findings thus far, and making 'reasonable' assumptions about the construction costs of community facilities, BARC estimates that the total rehabilitation costs will lie in the range of $55 to $90 million. Most of the range is due to uncertainty regarding the decontamination program. (author)

  15. Certified reference materials for radionuclides in Bikini Atoll sediment (IAEA-410) and Pacific Ocean sediment (IAEA-412)

    DEFF Research Database (Denmark)

    Pham, M. K.; van Beek, P.; Carvalho, F. P.

    2016-01-01

    The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified...... radionuclides include: 40K, 210Pb (210Po), 226Ra, 228Ra, 228Th, 232Th, 234U, 238U, 239Pu, 239+240Pu and 241Am for IAEA-410 and 40K, 137Cs, 210Pb (210Po), 226Ra, 228Ra, 228Th, 232Th, 235U, 238U, 239Pu, 240Pu and 239+240Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes...

  16. Recommender Systems for Learning

    CERN Document Server

    Manouselis, Nikos; Verbert, Katrien; Duval, Erik

    2013-01-01

    Technology enhanced learning (TEL) aims to design, develop and test sociotechnical innovations that will support and enhance learning practices of both individuals and organisations. It is therefore an application domain that generally covers technologies that support all forms of teaching and learning activities. Since information retrieval (in terms of searching for relevant learning resources to support teachers or learners) is a pivotal activity in TEL, the deployment of recommender systems has attracted increased interest. This brief attempts to provide an introduction to recommender systems for TEL settings, as well as to highlight their particularities compared to recommender systems for other application domains.

  17. 1990 recommendations of ICRP

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1991-01-01

    The Main Commission of ICRP finalised its new recommendations during its November 1990 meeting. The recommendations will appear in the Annals of the ICRP in 1991 as Publication 60. This paper represents a personal summary of these recommendations. It covers the basic biological risk estimates and the conceptual framework of the system of radiological protection, the definition of radiation detriment and its use both in the definition of radiation quantities and in the establishment of the dose limits adopted by the Main Commissions. (author)

  18. Drivers of abundance and spatial distribution of reef-associated sharks in an isolated atoll reef system.

    Directory of Open Access Journals (Sweden)

    David M Tickler

    Full Text Available We investigated drivers of reef shark demography across a large and isolated marine protected area, the British Indian Ocean Territory Marine Reserve, using stereo baited remote underwater video systems. We modelled shark abundance against biotic and abiotic variables at 35 sites across the reserve and found that the biomass of low trophic order fish (specifically planktivores had the greatest effect on shark abundance, although models also included habitat variables (depth, coral cover and site type. There was significant variation in the composition of the shark assemblage at different atolls within the reserve. In particular, the deepest habitat sampled (a seamount at 70-80m visited for the first time in this study recorded large numbers of scalloped hammerhead sharks (Sphyrna lewini not observed elsewhere. Size structure of the most abundant and common species, grey reef sharks (Carcharhinus amblyrhynchos, varied with location. Individuals at an isolated bank were 30% smaller than those at the main atolls, with size structure significantly biased towards the size range for young of year (YOY. The 18 individuals judged to be YOY represented the offspring of between four and six females, so, whilst inconclusive, these data suggest the possible use of a common pupping site by grey reef sharks. The importance of low trophic order fish biomass (i.e. potential prey in predicting spatial variation in shark abundance is consistent with other studies both in marine and terrestrial systems which suggest that prey availability may be a more important predictor of predator distribution than habitat suitability. This result supports the need for ecosystem level rather than species-specific conservation measures to support shark recovery. The observed spatial partitioning amongst sites for species and life-stages also implies the need to include a diversity of habitats and reef types within a protected area for adequate protection of reef-associated shark

  19. The shark assemblage at French Frigate Shoals atoll, Hawai'i: species composition, abundance and habitat use.

    Science.gov (United States)

    Dale, Jonathan J; Stankus, Austin M; Burns, Michael S; Meyer, Carl G

    2011-02-10

    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao M(h) ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289-1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling.

  20. Land-use change and managed aquifer recharge effects on the hydrogeochemistry of two contrasting atoll island aquifers, Roi-Namur Island, Republic of the Marshall Islands

    International Nuclear Information System (INIS)

    Hejazian, Mehrdad; Gurdak, Jason J.; Swarzenski, Peter; Odigie, Kingsley O.; Storlazzi, Curt D.

    2017-01-01

    Freshwater resources on low-lying atoll islands are highly vulnerable to climate change and sea-level rise. In addition to rainwater catchment, groundwater in the freshwater lens is a critically important water resource on many atoll islands, especially during drought. Although many atolls have high annual rainfall rates, dense natural vegetation and high evapotranspiration rates can limit recharge to the freshwater lens. Here we evaluate the effects of land-use/land-cover change and managed aquifer recharge on the hydrogeochemistry and supply of groundwater on Roi-Namur Island, Republic of the Marshall Islands. Roi-Namur is an artificially conjoined island that has similar hydrogeology on the Roi and Namur lobes, but has contrasting land-use/land-cover and managed aquifer recharge only on Roi. Vegetation removal and managed aquifer recharge operations have resulted in an estimated 8.6 × 10"5 m"3 of potable groundwater in the freshwater lens on Roi, compared to only 1.6 × 10"4 m"3 on Namur. We use groundwater samples from a suite of 33 vertically nested monitoring wells, statistical testing, and geochemical modeling using PHREEQC to show that the differences in land-use/land-cover and managed aquifer recharge on Roi and Namur have a statistically significant effect on several groundwater-quality parameters and the controlling geochemical processes. Results also indicate a six-fold reduction in the dissolution of carbonate rock in the freshwater lens and overlying vadose zone of Roi compared to Namur. Mixing of seawater and the freshwater lens is a more dominant hydrogeochemical process on Roi because of the greater recharge and flushing of the aquifer with freshwater as compared to Namur. In contrast, equilibrium processes and dissolution-precipitation non-equilibrium reactions are more dominant on Namur because of the longer residence times relative to the rate of geochemical reactions. Findings from Roi-Namur Island support selective land

  1. Probabilistic approaches to recommendations

    CERN Document Server

    Barbieri, Nicola; Ritacco, Ettore

    2014-01-01

    The importance of accurate recommender systems has been widely recognized by academia and industry, and recommendation is rapidly becoming one of the most successful applications of data mining and machine learning. Understanding and predicting the choices and preferences of users is a challenging task: real-world scenarios involve users behaving in complex situations, where prior beliefs, specific tendencies, and reciprocal influences jointly contribute to determining the preferences of users toward huge amounts of information, services, and products. Probabilistic modeling represents a robus

  2. The decision-making process in returning relocated populations to the Marshall Islands

    International Nuclear Information System (INIS)

    Bell, T.

    1998-01-01

    Between 1946 and 1958, the United States conducted a nuclear weapons testing program in the northern Marshall Islands, detonating 66 nuclear weapons at Bikini and Enewetak. The indigenous populations at Bikini and Enewetak Atolls were evacuated prior to the initiation of testing at these respective atolls. Fallout in these cases were typically distributed within a few miles of the detonation. The 15-megaton thermonuclear Bravo device at Bikini resulted in the inadvertent deposition of radioactive fallout on the 253 inhabitants of Rongelap and Utirik atolls. The Rongelap and Utirik populations had not been evacuated prior to this test designed to detonate at about 5 megatons. 65 Rongelap individuals received whole body fallout doses of about 1.8 sievert (180 rem), 18 Ailinginae individuals received whole body doses of about 0.7 sievert (70 rem), and 157 Marshallese individuals at Utirik received a whole body fallout doses of about 0.14 sievert (14 rem.) The U.S. Department of Energy (DOE) and its predecessor agencies have provided special medical surveillance and treatment of radiation-related injury and illness for the surviving members of the populations of Rongelap and Utirik exposed during the 'Bravo' test. In addition, DOE conducts environmental and radiological monitoring and performs agricultural research studies to characterize the radioactivity remaining at the four atolls of Bikini in the aftermath of the 1946-58 U.S. nuclear testing program. (R.P.)

  3. A Hybrid Recommender System Based on User-Recommender Interaction

    OpenAIRE

    Zhang, Heng-Ru; Min, Fan; He, Xu; Xu, Yuan-Yuan

    2015-01-01

    Recommender systems are used to make recommendations about products, information, or services for users. Most existing recommender systems implicitly assume one particular type of user behavior. However, they seldom consider user-recommender interactive scenarios in real-world environments. In this paper, we propose a hybrid recommender system based on user-recommender interaction and evaluate its performance with recall and diversity metrics. First, we define the user-recommender interaction...

  4. Host tolerance, not symbiont tolerance, determines the distribution of coral species in relation to their environment at a Central Pacific atoll

    Science.gov (United States)

    Wicks, L. C.; Gardner, J. P. A.; Davy, S. K.

    2012-06-01

    Tolerance of environmental variables differs between corals and their dinoflagellate symbionts ( Symbiodinium spp.), controlling the holobiont's (host and symbiont combined) resilience to environmental stress. However, the ecological role that environmental variables play in holobiont distribution remains poorly understood. We compared the drivers of symbiont and coral species distributions at Palmyra Atoll, a location with a range of reef environments from low to high sediment concentrations (1-52 g dry weight m-2 day-1). We observed uniform holobiont partnerships across the atoll (e.g. Montipora spp. with Symbiodinium type C15 at all sites). Multivariate analysis revealed that field-based estimates of settling sediment predominantly explained the spatial variation of coral species among sites ( P coral rather than Symbiodinium physiology. The data highlight the importance of host tolerance to environmental stressors, which should be considered simultaneously with symbiont sensitivity when considering the impact of variations in environmental conditions on coral communities.

  5. Mineralogy, geochemistry and microfacies of late Quaternary periplatform sediments: Carbonate export cycles and secondary processes - Sanganeb Atoll and Abington Reef, Sudan, Central Red Sea

    OpenAIRE

    Emmermann, Peter

    2000-01-01

    A set of sediment cores was obtained in the periplatform realm close to Sanganeb Atoll and Abington Reef, about 20 miles offshore the Sudanese coast in the central Red Sea. Microfacies, mineralogy and geochemistry of periplatform sediments were analysed to quantify glacial-interglacial variations in carbonate production and sediment export of the reefs in response to late Quaternary sealevel fluctuations. The present study showed that the periplatform sediments from the Sudanese shelf to grea...

  6. Análisis de las estrategias de gestión del espectro radioeléctrico en un sistema LTE con la herramienta Atoll

    OpenAIRE

    López Diaz, Eduardo José

    2012-01-01

    Estudiar el impacto de usar una estrategia ICIC y los posibles esquemas de reuso frecuencial en un sistema LTE. English: the Mobile Communications Research Group as part of the Signal Theory and Communications Department of the Polytechnic University of Catalonia, in order to keep up with the latest technological trends in the mobile networks field, saw the need to study and analyze the new emerging mobile standards such as LTE (Long Term Evolution), and through Atoll, a mobile network rad...

  7. Summary (and) recommendations

    International Nuclear Information System (INIS)

    1992-01-01

    This report looks at the Health and Safety record at the Atomic Weapons Establishment at Aldermaston. The last outside report was by Pochin in 1978 which recommended that staffing for health physicists and maintenance staff should be increased and that some buildings where solid and liquid radioactive wastes were processed should be replaced. A new facility to process contaminated heavy equipment was also recommended. This report finds that none of the recommendations have been fully implemented. It also lists accidents, fires and worker contamination. It is concluded that some of the problems are that nuclear weapons production is inherently unsafe and cannot be made safe, that the secrecy surrounding the establishments' safety record is not good for improving it and finally the report calls for production at Aldermaston to be halted. (UK)

  8. Archetypal Game Recommender Systems

    DEFF Research Database (Denmark)

    Sifa, Rafet; Bauckhage, C.; Drachen, Anders

    2014-01-01

    Contemporary users (players, consumers) of digital games have thousands of products to choose from, which makes nding games that t their interests challenging. Towards addressing this challenge, in this paper two dierent formulations of Archetypal Analysis for Top-L recommender tasks using implicit...... feedback are presented: factor- and neighborhood-oriented models. These form the rst application of rec- ommender systems to digital games. Both models are tested on a dataset of 500,000 users of the game distribution platform Steam, covering game ownership and playtime data across more than 3000 games....... Compared to four other recommender models (nearest neighbor, two popularity mod- els, random baseline), the archetype based models provide the highest recall rates showing that Archetypal Analysis can be successfully applied for Top-L recommendation purposes...

  9. OARSI Clinical Trials Recommendations

    DEFF Research Database (Denmark)

    Emery, C. A.; Roos, Ewa M.; Verhagen, E.

    2015-01-01

    The risk of post-traumatic osteoarthritis (PTOA) substantially increases following joint injury. Research efforts should focus on investigating the efficacy of preventative strategies in high quality randomized controlled trials (RCT). The objective of these OARSI RCT recommendations is to inform...... the design, conduct and analytical approaches to RCTs evaluating the preventative effect of joint injury prevention strategies. Recommendations regarding the design, conduct, and reporting of RCTs evaluating injury prevention interventions were established based on the consensus of nine researchers...... internationally with expertise in epidemiology, injury prevention and/or osteoarthritis (OA). Input and resultant consensus was established through teleconference, face to face and email correspondence over a 1 year period. Recommendations for injury prevention RCTs include context specific considerations...

  10. Recommending Multidimensional Queries

    Science.gov (United States)

    Giacometti, Arnaud; Marcel, Patrick; Negre, Elsa

    Interactive analysis of datacube, in which a user navigates a cube by launching a sequence of queries is often tedious since the user may have no idea of what the forthcoming query should be in his current analysis. To better support this process we propose in this paper to apply a Collaborative Work approach that leverages former explorations of the cube to recommend OLAP queries. The system that we have developed adapts Approximate String Matching, a technique popular in Information Retrieval, to match the current analysis with the former explorations and help suggesting a query to the user. Our approach has been implemented with the open source Mondrian OLAP server to recommend MDX queries and we have carried out some preliminary experiments that show its efficiency for generating effective query recommendations.

  11. New Insulin Delivery Recommendations.

    Science.gov (United States)

    Frid, Anders H; Kreugel, Gillian; Grassi, Giorgio; Halimi, Serge; Hicks, Debbie; Hirsch, Laurence J; Smith, Mike J; Wellhoener, Regine; Bode, Bruce W; Hirsch, Irl B; Kalra, Sanjay; Ji, Linong; Strauss, Kenneth W

    2016-09-01

    Many primary care professionals manage injection or infusion therapies in patients with diabetes. Few published guidelines have been available to help such professionals and their patients manage these therapies. Herein, we present new, practical, and comprehensive recommendations for diabetes injections and infusions. These recommendations were informed by a large international survey of current practice and were written and vetted by 183 diabetes experts from 54 countries at the Forum for Injection Technique and Therapy: Expert Recommendations (FITTER) workshop held in Rome, Italy, in 2015. Recommendations are organized around the themes of anatomy, physiology, pathology, psychology, and technology. Key among the recommendations are that the shortest needles (currently the 4-mm pen and 6-mm syringe needles) are safe, effective, and less painful and should be the first-line choice in all patient categories; intramuscular injections should be avoided, especially with long-acting insulins, because severe hypoglycemia may result; lipohypertrophy is a frequent complication of therapy that distorts insulin absorption, and, therefore, injections and infusions should not be given into these lesions and correct site rotation will help prevent them; effective long-term therapy with insulin is critically dependent on addressing psychological hurdles upstream, even before insulin has been started; inappropriate disposal of used sharps poses a risk of infection with blood-borne pathogens; and mitigation is possible with proper training, effective disposal strategies, and the use of safety devices. Adherence to these new recommendations should lead to more effective therapies, improved outcomes, and lower costs for patients with diabetes. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  12. Review of ICRP recommendations

    International Nuclear Information System (INIS)

    Goldfinch, E.P.

    1987-01-01

    Events in both the scientific world and in the public domain have added pressure to review the recommendations of the ICRP on which radiation protection legislation in most countries is founded. A brief editorial pleads for clarity in ICRP recommendations, suggests the use solely of cumulative with age individual occupational dose limits, suggests that collective doses including both occupational and to the public should be kept as low as reasonably achievable, judged on quantitative economic grounds, and suggests the setting of a probability for serious accidents which may be disregarded in planning. (UK)

  13. Privacy enhanced recommender system

    NARCIS (Netherlands)

    Erkin, Zekeriya; Erkin, Zekeriya; Beye, Michael; Veugen, Thijs; Lagendijk, Reginald L.

    2010-01-01

    Recommender systems are widely used in online applications since they enable personalized service to the users. The underlying collaborative filtering techniques work on user’s data which are mostly privacy sensitive and can be misused by the service provider. To protect the privacy of the users, we

  14. Recommendations for Alternative Credit.

    Science.gov (United States)

    Lenderman, Ed; And Others

    Following a review of the mathematics topics taught in accounting, electronics, auto, food and clothing, and metals courses at Linn-Benton Community College, Albany, Oregon, recommendations were made to grant one semester of mathematics credit for completing a two-year sequence of these courses. The other required semester of mathematics should be…

  15. Towards Geosocial Recommender Systems

    NARCIS (Netherlands)

    de Graaff, V.; van Keulen, Maurice; de By, R.A.; de By, Rolf A.

    2012-01-01

    The usage of social networks sites (SNSs), such as Facebook, and geosocial networks (GSNs), such as Foursquare, has increased tremendously over the past years. The willingness of users to share their current locations and experiences facilitate the creation of geographical recommender systems based

  16. Search and Recommendation

    DEFF Research Database (Denmark)

    Bogers, Toine

    2014-01-01

    In just a little over half a century, the field of information retrieval has experienced spectacular growth and success, with IR applications such as search engines becoming a billion-dollar industry in the past decades. Recommender systems have seen an even more meteoric rise to success with wide...

  17. Chapter 10: Management recommendations

    Science.gov (United States)

    Deborah M. Finch; Janie Agyagos; Tracy McCarthey; Robert M. Marshall; Scott H. Stoleson; Mary J. Whitfield

    2000-01-01

    This chapter was developed over a series of meetings using a group-consensus process. Our recommendations are based on published results, on information compiled in the previous chapters, on expert opinion, and on unpublished data of conservation team members. This chapter is available as temporary guidance until the Recovery Plan for the southwestern willow flycatcher...

  18. Privacy in Recommender Systems

    NARCIS (Netherlands)

    Jeckmans, Arjan; Beye, Michael; Erkin, Zekeriya; Erkin, Zekeriya; Hartel, Pieter H.; Lagendijk, Reginald; Tang, Qiang; Ramzan, Naeem; van Zwol, Roelof; Lee, Jong-Seok; Clüver, Kai; Hua, Xian-Sheng

    In many online applications, the range of content that is offered to users is so wide that a need for automated recommender systems arises. Such systems can provide a personalized selection of relevant items to users. In practice, this can help people find entertaining movies, boost sales through

  19. The ICRP 2007 recommendations

    International Nuclear Information System (INIS)

    Streffer, C.

    2007-01-01

    The last comprehensive International Commission on Radiological Protection (ICRP) recommendations have been published in 1991(1). Since that time new data in physics and biology that are relevant for radiological protection have appeared in the scientific literature. Also, the general thinking about safety standards at the workplace as well as for the protection of the public has developed. Thus, a review of the recommendations is needed. However, as the present standards have worked well, these new recommendations should build on the present ones. Only a process of further development should take place allowing for the following key points: - new biological and physical information and trends in the setting of safety standards; - improvement in the presentation of the recommendations; as much stability in the recommendations as is consistent with the new information and environmental aspects will be included. The fundamental principles of radiological protection will remain the same as they have been described in ICRP publication 60(1): Justification: Actions involving new exposures or changes in exposures of individuals have to be justified in advance. A positive net benefit must result. Optimisation: Exposures should be as low as reasonably achievable and should be optimised in relation to with dose constraints. Dose limits: The values will not to be changed from Publication 60. Dose constraints: Development of the concept proposed in Publication 60 will be explained. The ICRP Committees have prepared foundation documents in the fields for which they are responsible and their members have the corresponding expertise. These foundation documents will support the decisions and explain the various statements of the Main Commission in a broader sense. Some of them will be published as Annexes to the recommendations (Annex A: Biological and Epidemiological Information on Health Risks Attributable to Ionising Radiation; Annex B: Quantities used in Radiological

  20. The ICRP 2007 recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Streffer, C. [Chairman of ICRP Committee 2, Institute of Science and Ethics, University Duisburg-Essen, 45117 Essen (Germany)

    2007-07-01

    The last comprehensive International Commission on Radiological Protection (ICRP) recommendations have been published in 1991(1). Since that time new data in physics and biology that are relevant for radiological protection have appeared in the scientific literature. Also, the general thinking about safety standards at the workplace as well as for the protection of the public has developed. Thus, a review of the recommendations is needed. However, as the present standards have worked well, these new recommendations should build on the present ones. Only a process of further development should take place allowing for the following key points: - new biological and physical information and trends in the setting of safety standards; - improvement in the presentation of the recommendations; as much stability in the recommendations as is consistent with the new information and environmental aspects will be included. The fundamental principles of radiological protection will remain the same as they have been described in ICRP publication 60(1): Justification: Actions involving new exposures or changes in exposures of individuals have to be justified in advance. A positive net benefit must result. Optimisation: Exposures should be as low as reasonably achievable and should be optimised in relation to with dose constraints. Dose limits: The values will not to be changed from Publication 60. Dose constraints: Development of the concept proposed in Publication 60 will be explained. The ICRP Committees have prepared foundation documents in the fields for which they are responsible and their members have the corresponding expertise. These foundation documents will support the decisions and explain the various statements of the Main Commission in a broader sense. Some of them will be published as Annexes to the recommendations (Annex A: Biological and Epidemiological Information on Health Risks Attributable to Ionising Radiation; Annex B: Quantities used in Radiological

  1. Resolving high-frequency internal waves generated at an isolated coral atoll using an unstructured grid ocean model

    Science.gov (United States)

    Rayson, Matthew D.; Ivey, Gregory N.; Jones, Nicole L.; Fringer, Oliver B.

    2018-02-01

    We apply the unstructured grid hydrodynamic model SUNTANS to investigate the internal wave dynamics around Scott Reef, Western Australia, an isolated coral reef atoll located on the edge of the continental shelf in water depths of 500,m and more. The atoll is subject to strong semi-diurnal tidal forcing and consists of two relatively shallow lagoons separated by a 500 m deep, 2 km wide and 15 km long channel. We focus on the dynamics in this channel as the internal tide-driven flow and resulting mixing is thought to be a key mechanism controlling heat and nutrient fluxes into the reef lagoons. We use an unstructured grid to discretise the domain and capture both the complex topography and the range of internal wave length scales in the channel flow. The model internal wave field shows super-tidal frequency lee waves generated by the combination of the steep channel topography and strong tidal flow. We evaluate the model performance using observations of velocity and temperature from two through water-column moorings in the channel separating the two reefs. Three different global ocean state estimate datasets (global HYCOM, CSIRO Bluelink, CSIRO climatology atlas) were used to provide the model initial and boundary conditions, and the model outputs from each were evaluated against the field observations. The scenario incorporating the CSIRO Bluelink data performed best in terms of through-water column Murphy skill scores of water temperature and eastward velocity variability in the channel. The model captures the observed vertical structure of the tidal (M2) and super-tidal (M4) frequency temperature and velocity oscillations. The model also predicts the direction and magnitude of the M2 internal tide energy flux. An energy analysis reveals a net convergence of the M2 energy flux and a divergence of the M4 energy flux in the channel, indicating the channel is a region of either energy transfer to higher frequencies or energy loss to dissipation. This conclusion is

  2. An updated dose assessment for resettlement options at Bikini Atoll--a U.S. nuclear test site.

    Science.gov (United States)

    Robison, W L; Bogen, K T; Conrado, C L

    1997-07-01

    On 1 March 1954, a nuclear weapon test, code-named BRAVO, conducted at Bikini Atoll in the northern Marshall Islands contaminated the major residence island. There has been a continuing effort since 1977 to refine dose assessments for resettlement options at Bikini Atoll. Here we provide a radiological dose assessment for the main residence island, Bikini, using extensive radionuclide concentration data derived from analysis of food crops, ground water, cistern water, fish and other marine species, animals, air, and soil collected at Bikini Island as part of our continuing research and monitoring program that began in 1978. The unique composition of coral soil greatly alters the relative contribution of 137Cs and 90Sr to the total estimated dose relative to expectations based on North American and European soils. Without counter measures, 137Cs produces 96% of the estimated dose for returning residents, mostly through uptake from the soil to terrestrial food crops but also from external gamma exposure. The doses are calculated assuming a resettlement date of 1999. The estimated maximum annual effective dose for current island conditions is 4.0 mSv when imported foods, which are now an established part of the diet, are available. The 30-, 50-, and 70-y integral effective doses are 91 mSv, 130 mSv, and 150 mSv, respectively. A detailed uncertainty analysis for these dose estimates is presented in a companion paper in this issue. We have evaluated various countermeasures to reduce 137Cs in food crops. Treatment with potassium reduces the uptake of 137Cs into food crops, and therefore the ingestion dose, to about 5% of pretreatment levels and has essentially no negative environmental consequences. We have calculated the dose for the rehabilitation scenario where the top 40 cm of soil is removed in the housing and village area, and the rest of the island is treated with potassium fertilizer; the maximum annual effective dose is 0.41 mSv and the 30-, 50-, and 70-y

  3. Numerical simulation of passive tracer dispersion in the pacific ocean from Mururoa atoll (French Polynesia); Etude numerique de la dispersion d`un traceur dans le pacifique sud depuis l`atoll de Mururoa

    Energy Technology Data Exchange (ETDEWEB)

    Rancher, J.; Lazar, A.; Maes, Ch.

    1996-12-01

    In order to evaluate, on a Tropical South Pacific scale over 10 years, the consequences of an hypothetic radionuclide releases to the ocean from French Nuclear test sites, a series of numerical simulations was carried out. Tracer advection and diffusion terms were computed by a dispersion model without taking into account radioactive decay and biological interactions. Ocean dynamics and turbulent mixing coefficients were derived from a Ocean General circulation Model using annual average climatological fields. A punctual release with unit activity concentration throughout the depth showed the existence of two major directions of propagation from Mururoa atoll: one toward the Eastern Pacific when releases originated from 100-150 meters or less, and the other Westward if release depth is greater. The maximum concentrations which may possibly reach the continental South Pacific coastline originated from released points located in the 350 meters depth zone. Another experiment showed that an punctual release yields higher concentrations than the continuous release of an equivalent quantity over 10 years; two punctual releases were carried out at the characteristic depth of 5 m and 364 m: maximum concentrations decrease by factors of 10 000 and 1000 over ten years. A comparison is made with the surface release study of Ribbe and Tomczak (1990), despite a significant discrepancy in propagation direction, the order of magnitude for concentrations is comparable. (author).

  4. ICRS Recommendation Document

    DEFF Research Database (Denmark)

    Roos, Ewa M.; Engelhart, Luella; Ranstam, Jonas

    2011-01-01

    and function evaluated for validity and psychometric properties in patients with articular cartilage lesions. Results: The knee-specific instruments, titled the International Knee Documentation Committee Subjective Knee Form and the Knee injury and Osteoarthritis and Outcome Score, both fulfill the basic......Abstract Objective: The purpose of this article is to describe and recommend patient-reported outcome instruments for use in patients with articular cartilage lesions undergoing cartilage repair interventions. Methods: Nonsystematic literature search identifying measures addressing pain...... constructs at all levels according to the International Classification of Functioning. Conclusions: Because there is no obvious superiority of either instrument at this time, both outcome measures are recommended for use in cartilage repair. Rescaling of the Lysholm Scoring Scale has been suggested...

  5. Badali recommends simplified bills

    International Nuclear Information System (INIS)

    Anon

    2003-01-01

    A report on the variety of retail electricity bills across the province, authored by Salvatore Badali of Deloitte Consulting, was recently released by the Ontario Government. The report was commissioned by the Government to examine the underlying reasons for the significant format differences and the wide variation of fixed and variable charges among the approximately 95 local electricity distribution companies across the province. Regarding the appropriateness of the charges the report recommends common definitions for local distribution company (LDC) fixed and variable costs, and consideration of options for reducing LDC charges, mainly by consolidating the sector and sharing such services as customer billing, accounting and out sourcing operations. Seven recommendations deal with bill simplification. These include bills that are clear and easy to read and provide sufficient information for consumers to verify charges; promote energy conservation, e.g. by including historical information; allow comparisons between retail suppliers and distributors; accommodate revenue collection, marketing needs and other billing services. The report also recommends clearly defined and consistently used terminology for standardized line items, suggests ways to provide consumer information in a form useful for making energy conservation decisions, development of an LDC scorecard to enable stake holders to compare their own LDCs with LDCs around the province, creation of a conservation and bill calculation website, consideration of further use of shared services, and solutions to address the removal of line losses from invoices

  6. Badali recommends simplified bills

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2003-04-01

    A report on the variety of retail electricity bills across the province, authored by Salvatore Badali of Deloitte Consulting, was recently released by the Ontario Government. The report was commissioned by the Government to examine the underlying reasons for the significant format differences and the wide variation of fixed and variable charges among the approximately 95 local electricity distribution companies across the province. Regarding the appropriateness of the charges the report recommends common definitions for local distribution company (LDC) fixed and variable costs, and consideration of options for reducing LDC charges, mainly by consolidating the sector and sharing such services as customer billing, accounting and out sourcing operations. Seven recommendations deal with bill simplification. These include bills that are clear and easy to read and provide sufficient information for consumers to verify charges; promote energy conservation, e.g. by including historical information; allow comparisons between retail suppliers and distributors; accommodate revenue collection, marketing needs and other billing services. The report also recommends clearly defined and consistently used terminology for standardized line items, suggests ways to provide consumer information in a form useful for making energy conservation decisions, development of an LDC scorecard to enable stake holders to compare their own LDCs with LDCs around the province, creation of a conservation and bill calculation website, consideration of further use of shared services, and solutions to address the removal of line losses from invoices.

  7. Phylogenetic analysis of a microbialite-forming microbial mat from a hypersaline lake of the Kiritimati atoll, Central Pacific.

    Science.gov (United States)

    Schneider, Dominik; Arp, Gernot; Reimer, Andreas; Reitner, Joachim; Daniel, Rolf

    2013-01-01

    On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰). Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster), which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria), Chloroflexi (Anaerolineae and Caldilineae), purple non-sulfur bacteria (Alphaproteobacteria), purple sulfur bacteria (Chromatiales), anaerobic Bacteroidetes (Marinilabiacae), Nitrospirae (OPB95), Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata) to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B) with increasing depth.

  8. Phylogenetic analysis of a microbialite-forming microbial mat from a hypersaline lake of the Kiritimati atoll, Central Pacific.

    Directory of Open Access Journals (Sweden)

    Dominik Schneider

    Full Text Available On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰. Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster, which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria, Chloroflexi (Anaerolineae and Caldilineae, purple non-sulfur bacteria (Alphaproteobacteria, purple sulfur bacteria (Chromatiales, anaerobic Bacteroidetes (Marinilabiacae, Nitrospirae (OPB95, Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B with increasing depth.

  9. Calcium dynamics in microbialite-forming exopolymer-rich mats on the atoll of Kiritimati, Republic of Kiribati, Central Pacific.

    Science.gov (United States)

    Ionescu, D; Spitzer, S; Reimer, A; Schneider, D; Daniel, R; Reitner, J; de Beer, D; Arp, G

    2015-03-01

    Microbialite-forming microbial mats in a hypersaline lake on the atoll of Kiritimati were investigated with respect to microgradients, bulk water chemistry, and microbial community composition. O2, H2S, and pH microgradients show patterns as commonly observed for phototrophic mats with cyanobacteria-dominated primary production in upper layers, an intermediate purple layer with sulfide oxidation, and anaerobic bottom layers with sulfate reduction. Ca(2+) profiles, however, measured in daylight showed an increase of Ca(2+) with depth in the oxic zone, followed by a sharp decline and low concentrations in anaerobic mat layers. In contrast, dark measurements show a constant Ca(2+) concentration throughout the entire measured depth. This is explained by an oxygen-dependent heterotrophic decomposition of Ca(2+)-binding exopolymers. Strikingly, the daylight maximum in Ca(2+) and subsequent drop coincides with a major zone of aragonite and gypsum precipitation at the transition from the cyanobacterial layer to the purple sulfur bacterial layer. Therefore, we suggest that Ca(2+) binding exopolymers function as Ca(2+) shuttle by their passive downward transport through compression, triggering aragonite precipitation in the mats upon their aerobic microbial decomposition and secondary Ca(2+) release. This precipitation is mediated by phototrophic sulfide oxidizers whose action additionally leads to the precipitation of part of the available Ca(2+) as gypsum. © 2014 John Wiley & Sons Ltd.

  10. Independent Verification Survey of the Clean Coral Storage Pile at the Johnston Atoll Plutonium Contaminated Soil Remediation Project

    International Nuclear Information System (INIS)

    Wilson-Nichols, M.J.; Egidi, P.V.; Roemer, E.K.; Schlosser, R.M.

    2000-01-01

    f I The Oak Ridge National Laboratory (ORNL) Environmental Technology Section conducted an independent verification (IV) survey of the clean storage pile at the Johnston Atoll Plutonium Contaminated Soil Remediation Project (JAPCSRP) from January 18-25, 1999. The goal of the JAPCSRP is to restore a 24-acre area that was contaminated with plutonium oxide particles during nuclear testing in the 1960s. The selected remedy was a soil sorting operation that combined radiological measurements and mining processes to identify and sequester plutonium-contaminated soil. The soil sorter operated from about 1990 to 1998. The remaining clean soil is stored on-site for planned beneficial use on Johnston Island. The clean storage pile currently consists of approximately 120,000 m3 of coral. ORNL conducted the survey according to a Sampling and Analysis Plan, which proposed to provide an IV of the clean pile by collecting a minimum number (99) of samples. The goal was to ascertain wi th 95% confidence whether 97% of the processed soil is less than or equal to the accepted guideline (500-Bq/kg or 13.5-pCi/g) total transuranic (TRU) activity

  11. PSI contribution to the IAEA study on the radiological situation at the atolls of Mururoa and Fangataufa

    International Nuclear Information System (INIS)

    Pfingsten, W.; Hadermann, J.

    1999-01-01

    Upon the definitive end of the French atomic bomb tests in the South Pacific, the International Atomic Energy Agency (IAEA) was asked to evaluate the radiological situation at the atolls of Mururoa and Fangataufa. The IAEA put up various working groups and invited PSI to participate in the group of geosphere radionuclide transport. Together with the other members of the Working Group, PSI developed models, performed calculations and assessed the radionuclide releases from the various sources and the transport of radionuclides through the geological layers. There were 137 underground sources at Mururoa and 10 at Fangataufa. Release via the groundwater has been assessed for radionuclides which were judged of potential importance, 35 in number. Certain nuclides, notably 3 H, 90 Sr, 137 Cs and 239 Pu were investigated in more detail. Data and, partially, model uncertainty was handled by varying the parameters and by comparing differing model concepts. In cases of lack of data ; assumptions were made such that nuclide fluxes are deemed to be overestimated. Calculated results could partially be checked against experimental information. Radionuclide concentrations observed at various test sites are consistent with results from the solution source term model. Calculated releases to the lagoon are generally consistent with measurements. The analysis of all test categories has shown that the radionuclide release to either the lagoon or the ocean is dominated by a few tests. (author)

  12. Phylogenetic and functional diversity of Bacteria and Archaea in a unique stratified lagoon, the Clipperton atoll (N Pacific).

    Science.gov (United States)

    Galand, Pierre E; Bourrain, Muriel; De Maistre, Emmanuel; Catala, Philippe; Desdevises, Yves; Elifantz, Hila; Kirchman, David L; Lebaron, Philippe

    2012-01-01

    The Clipperton lagoon in the North Pacific Ocean has been isolated from the surrounding sea for c. 160 years. It has a stratified water column that comprises an oxic and brackish upper water layer (mixolimnion) and a deep sulfuric anoxic saline layer (monimolimnion), separated by a steep pycnocline. Here, we test whether the Clipperton lagoon with its distinctive physico-chemical features, geographic isolation, recent water column stratification, and large nutrient input harbors original microbial communities. The combination of capillary electrophoresis single-strand polymorphism (CE-SSCP) fingerprinting and sequencing of cloned bacterial and archaeal 16S rRNA genes, and functional genes for methanogenesis (mcrA), methanotrophy (pmoA), and sulfate reduction (dsrAB), revealed that microbial communities and pathways were highly stratified down the water column. The mixolimnion contained ubiquitous freshwater clades of Alpha- and Betaproteobacteria, while the pycnocline contained mostly green sulfur bacteria (phylum Chlorobi). Sequences of the upper layers were closely related to sequences found in other aquatic ecosystems, suggesting that they have a strong potential for dispersal and colonization. In contrast, the monimolimnion contained new deeply branching bacterial divisions within the OP11 cluster and the Bacteroidetes, and was the most diverse of the layers. The unique environmental conditions characterizing the deep layers of the lagoon may explain the novelty of the microbial communities found at the Clipperton atoll.

  13. Amount and type of derelict gear from the declining black pearl oyster aquaculture in Ahe atoll lagoon, French Polynesia.

    Science.gov (United States)

    Andréfouët, Serge; Thomas, Yoann; Lo, Cedrik

    2014-06-15

    Pearl oyster aquaculture is a major activity in French Polynesia atoll lagoons. After the economic decline that characterized the last decade, concerns recently rose about discarded installations and materials that supported aquaculture practices and by facilities abandoned after they had to close their activities. In May 2013, a first inventory of the type and amount of pearl farms derelict gear (PFDG) was achieved on 47 sites in Ahe lagoon. Surveys were conducted within and outside the boundaries of aquaculture concessions. Twenty types of PFDG littered the lagoon floor and the water column. The most impacted areas were near abandoned grafting houses with up to nine types of PFDG. Forty-five percent of the sites were impacted, including outside concessions. While management authorities are fully aware of the problem, this first assessment is a wake-up call to stimulate the cleaning of lagoons, enhance awareness among farmers, and identify potential ecological consequences on lagoon ecosystems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. The application of PIT tags to measure transport of detrital coral fragments on a fringing reef: Majuro Atoll, Marshall Islands

    Science.gov (United States)

    Ford, Murray R.

    2014-06-01

    Passive integrated transponder (PIT) tags are a radio-frequency identification device widely used as a machine-readable identification tool in fisheries research. PIT tags have also been employed, to a lesser extent, to track the movement of gravel-sized clasts within fluvial and coastal systems. In this study, PIT tags were inserted into detrital coral fragments and used to establish source-sink transport pathways on a fringing reef on Majuro Atoll in the Marshall Islands. Results suggest the transport of gravel-sized material on the inter-tidal reef flat is exclusively across-reef towards the lagoon. Considerable variation in the distance travelled by fragments was observed. Fragments were largely intact and visually recognisable after almost 5 months on the reef flat. However, the branches of some recovered fragments had broken off and corallite abrasion was observed in recovered fragments. This study indicates that PIT tags are an inexpensive and powerful new addition to the suite of sediment transport and taphonomic tools for researchers working within coral reef systems.

  15. Formation and adjustment of typhoon-impacted reef islands interpreted from remote imagery: Nadikdik Atoll, Marshall Islands

    Science.gov (United States)

    Ford, Murray R.; Kench, Paul S.

    2014-06-01

    In 1905, a devastating typhoon hit Nadikdik Atoll (5°54‧ N and 172°09‧ E) in the southern Marshall Islands. Evidence suggests that large sections of reef islands on Nadikdik were overwashed and destroyed. Comparison of aerial photographs taken in 1945 and modern satellite imagery provides a unique record of the geomorphic adjustment of islands after the typhoon. Between 1945 and 2010 the vegetated area of islands on Nadikdik grew from 0.74 to 0.90 km2. Observed changes to Nadikdik reef islands manifested through a range of styles and were largely accretionary. Of note, the formation of a new island was tracked from an embryonic deposit to a fully vegetated and stable island over a 61 year period. Similarly, a number of previously discrete islands have agglomerated and formed a single larger island. These changes were rapid and indicate that reef island formation can occur quickly. Evidence suggests that despite the typhoon occurring over a century ago the geomorphic adjustment of islands is still on-going.

  16. Mobile Application Recommender System

    OpenAIRE

    Davidsson, Christoffer

    2010-01-01

    With the amount of mobile applications available increasing rapidly, users have to put a lot of effort into finding applications of interest. The purpose of this thesis is to investigate how to aid users in the process of discovering new mobile applications by providing them with recommendations. A prototype system is then built as a proof-of-concept. The work of the thesis is divided into three phases where the aim of the first phase is to study related work and related systems to identify p...

  17. Clinical Recommendation: Vulvovaginitis.

    Science.gov (United States)

    Zuckerman, Andrea; Romano, Mary

    2016-12-01

    Vulvovaginitis is a commonly encountered condition among prepubertal and adolescent females. The objective of this report is to provide the latest evidence regarding the diagnosis and management of vulvovaginitis in prepubertal and adolescent females. In this systematic review we used the Grading of Recommendations Assessment, Development and Evaluation evidence system. Vulvovaginal complaints are common in the pediatric and adolescent age group. The patient's age in conjunction with history and associated complaints will guide evaluation, diagnosis, and treatment. Treatment should include counseling on hygiene and voiding techniques as well as therapy for any specific pathogens identified. Copyright © 2016.

  18. The new ICRP recommendations

    International Nuclear Information System (INIS)

    Schlesinger, T.

    1977-01-01

    The new ICRP recommendations are based on the concept of risk. The doses received by workers have to be justified and kept as low as practically achievable. The acceptable annual occupational risk is of the order of 10 -4 . This corresponds to an average annual dose equivalent of about 5 mSv(0.5 Rem). The annual dose equivalent limit for whole body irradiation will remain 50 mSv/year (5 Rem/year) provided that the average is about 1/10th of this value. The concept of the critical organ is abandoned and is replaced by the concept of equidetriment. (author)

  19. Personalized professional content recommendation

    Science.gov (United States)

    Xu, Songhua

    2015-10-27

    A personalized content recommendation system includes a client interface configured to automatically monitor a user's information data stream transmitted on the Internet. A hybrid contextual behavioral and collaborative personal interest inference engine resident to a non-transient media generates automatic predictions about the interests of individual users of the system. A database server retains the user's personal interest profile based on a plurality of monitored information. The system also includes a server programmed to filter items in an incoming information stream with the personal interest profile and is further programmed to identify only those items of the incoming information stream that substantially match the personal interest profile.

  20. Recommender Systems in Commercial Use

    OpenAIRE

    Aldrich, Susan E.

    2011-01-01

    Commercial recommender systems are deployed by marketing teams to increase revenue and/or personalize user experience. Marketers evaluate recommender systems not on its algorithms but on how well the vendor‘s expertise and interfaces will support achieving business goals. Driven by a business model that pays based on recommendation success, vendors guide clients through continuous optimization of recommendations. While recommender technology is mature, the solutions and market are still young...

  1. Conclusions and recommendations

    International Nuclear Information System (INIS)

    Carrette, M.

    1997-01-01

    The paper presents conclusions and recommendations at the closing session of the NEA/OECD Workshop held at Fontenay-aux-Roses on 12-14 June 1995. The conclusions refer to issues like: public reaction to foodstuffs containing radioisotope concentrations under the danger standards, possible non-adherence of manufacturers, processors, distributors, et al, to the instructions and guidance from radiation protection specialists, integration of all the food chain factors in the elaboration of the emergency intervention programs, etc. Among the most significant recommendations the following may be mentioned: 1. Differences between different intervention levels and the maximum admissible levels agreed upon by national, regional or international nutrition authorities should be further studied; 2. Problems created by the Chernobyl accident (as for instance, the methods of treatment of food chain products containing unacceptable radioactivity concentrations) are still present and must be solved; 3. Further studies should be done on the socio-cultural aspects of the communication, particularly on the information in rural environment; 4. The preventive measures in agriculture should be implemented as rapidly as possible; 5. In elaborating programmes of agriculture countermeasures, the management of contaminated media, particularly, of forests and their effect on agriculture

  2. Ebola virus: recommendations

    CERN Multimedia

    CERN Medical Service

    2014-01-01

    The CERN Medical Service has been closely following, in particular via the WHO, the development of the Ebola virus outbreak currently affecting some African countries. This infectious disease may be passed on through direct contact with the bodily fluids of a sick person.   Based on the recommendations of the WHO and the two Host States, Switzerland and France, as updated on their respective websites, so far there has been no ban on travel to the countries concerned. However, unless it is absolutely essential, you are advised not to visit any of the countries affected by Ebola (Guinea, Republic of Sierra Leone, Liberia, Nigeria). The two Host States have established an alert system, and a check is carried out on departure from the airports of those countries. It is strongly recommended that you contact the Medical Service if you are travelling to those countries. We remind you to observe the basic rules of hygiene such as frequent hand washing, whatever your destination. The Medical Service is...

  3. Mining and representing recommendations in actively evolving recommender systems

    DEFF Research Database (Denmark)

    Assent, Ira

    2010-01-01

    Recommender systems provide an automatic means of filtering out interesting items, usually based on past similarity of user ratings. In previous work, we have suggested a model that allows users to actively build a recommender network. Users express trust, obtain transparency, and grow (anonymous......) recommender connections. In this work, we propose mining such active systems to generate easily understandable representations of the recommender network. Users may review these representations to provide active feedback. This approach further enhances the quality of recommendations, especially as topics...... of interest change over time. Most notably, it extends the amount of control users have over the model that the recommender network builds of their interests....

  4. Effects of Land-Use Change and Managed Aquifer Recharge on Geochemical Reactions with Implications for Groundwater Quantity and Quality in Atoll Island Aquifers, Roi-Namur, Republic of the Marshall Islands

    Science.gov (United States)

    Hejazian, M.; Swarzenski, P. W.; Gurdak, J. J.; Odigie, K. O.; Storlazzi, C. D.

    2015-12-01

    This study compares the hydrogeochemistry of two contrasting atoll groundwater systems in Roi-Namur, Republic of the Marshall Islands. Roi-Namur houses a U.S. Department of Defense military installation and presents an ideal study location where a human impacted aquifer is co-located next to a natural aquifer as part of two artificially conjoined atoll islands. The hydrogeology and geochemistry of carbonate atoll aquifers has been well studied, particularly because of its small, well-defined hydrologic system that allows for relatively precise modeling. However, it is unknown how changes in land-use/land cover and managed aquifer recharge (MAR) alters natural geochemical processes in atoll aquifers. A better understanding of this has implications on groundwater quantity and quality, carbonate dissolution, and best aquifer management practices in the context of rising sea level and saltwater intrusion. Roi has been heavily modified to house military and civilian operations; here, lack of vegetation and managed recharge has increased the volume of potable groundwater and affected the geochemical processes in the freshwater lens and saltwater transition zone. Namur is heavily vegetated and the hydrogeology is indicative of a natural atoll island. A suite of monitoring wells were sampled across both island settings for major ions, nutrients, trace elements, DOC/DIC, δ13C and δ18O/2H isotopes. By modeling geochemical reactions using a conservative mixing approach, we measure deviations from expected reactions and compare the two contrasting settings using derived geochemical profiles through a wide salinity spectrum. Results indicate that groundwater on Namur is more heavily depleted in δ13C and has greater dissolved inorganic carbon, suggesting higher microbial oxidation and greater dissolution within the carbonate aquifer. This suggests MAR and reduction of vegetation makes the groundwater supply on atoll islands more resilient to sea level rise.

  5. Conclusions and recommendations

    International Nuclear Information System (INIS)

    1984-01-01

    The FAO/IAEA/GSF/SIDA Co-ordinated Research Programme on Cereal Grain Protein Improvement by Nuclear Techniques was a follow-up to the FAO/IAEA/GSF Co-ordinated Research Programme on the Use of Nuclear Techniques for Seed Protein Improvement. It was initiated in 1969 and ended in 1981. The objectives of the meeting were to review and evaluate the achievements of the current and previous programmes in order to draw conclusions on the possibility of genetic improvement of cereal grain protein using nuclear techniques, to identify unsolved problems and to discuss and propose possible approaches for their solution. Through reviews and discussions, conclusions and recommendations were made by the participants

  6. Recommendations for skin decontamination

    International Nuclear Information System (INIS)

    1989-01-01

    Further to the reecommendations for determining the surface contamination of the skin and estimating the radiation exposure of the skin after contamination (SAAS-Mitt--89-16), measures for skin decontamination are recommended. They are necessary if (1) after simple decontamination by means of water, soap and brush without damaging the skin the surface contamination limits are exceeded and the radiation exposure to be expected for the undamaged healthy skin is estimated as to high, and if (2) a wound is contaminated. To remove skin contaminations, in general universally applicable, non-aggressive decontamination means and methods are sufficient. In special cases, nuclide-specific decontamination is required taking into account the properties of the radioactive substance

  7. Urgent recommendation. Interim report

    International Nuclear Information System (INIS)

    Nakano, Masayuki

    2000-01-01

    The Investigation Committee for Critical Accident at Uranium Processing Plant was founded immediately after the accident to investigate the cause of the accident and to establish measures to prevent the similar accident. On September 30, 1999 around 10:35, the Japan's first criticality accident occurred at JCO Co. Ltd. Uranium processing plant (auxiliary conversion plant) located at Tokai-mura Ibaraki-ken. The criticality continued on and off for approximately 20 hours after the first instantaneous criticality. The accident led the recommendation of tentative evacuation and sheltering indoors for residents living in the neighborhood. The serious exposure to neutrons happened to three workers. The dominant effect is dose due to neutrons and gamma rays from the precipitation tank. When the accident took place, three workers dissolved sequentially about 2.4 kg uranium powder with 18.8 % enrichment in the 10-litter bucket with nitric acid. The procedure of homogenization of uranium nitrate was supposed to be controlled using the shape-limited narrow storage column. Actually, however, the thick and large precipitation tank was used. As a result, about 16.6 kg of uranium was fed into the tank, which presumably caused criticality. The first notification by JCO was delayed and the following communication was not smooth. This led to the delay of correct understanding of the situation and made the initial proper response difficult, then followed by insufficient communication between the nation, prefecture, and local authority. Urgent recommendations were made on the following items; (1) Safety measures to be taken at the accident site, (2) health cares for residents and others, (3) Comprehensive safety securing at nuclear operators such as Establishment of the effective audit system, Safety education for employees and Qualification and licensing system, Safety related documents, etc. (4) Reconstruction of the government's safety regulations such as How safety regulation

  8. Land-use change and managed aquifer recharge effects on the hydrogeochemistry of two contrasting atoll island aquifers, Roi-Namur Island, Republic of the Marshall Islands

    Science.gov (United States)

    Hejazian, Mehrdad; Gurdak, Jason J.; Swarzenski, Peter W.; Odigie, Kingsley; Storlazzi, Curt

    2017-01-01

    Freshwater resources on low-lying atoll islands are highly vulnerable to climate change and sea-level rise. In addition to rainwater catchment, groundwater in the freshwater lens is a critically important water resource on many atoll islands, especially during drought. Although many atolls have high annual rainfall rates, dense natural vegetation and high evapotranspiration rates can limit recharge to the freshwater lens. Here we evaluate the effects of land-use/land-cover change and managed aquifer recharge on the hydrogeochemistry and supply of groundwater on Roi-Namur Island, Republic of the Marshall Islands. Roi-Namur is an artificially conjoined island that has similar hydrogeology on the Roi and Namur lobes, but has contrasting land-use/land-cover and managed aquifer recharge only on Roi. Vegetation removal and managed aquifer recharge operations have resulted in an estimated 8.6 x 105 m3 of potable groundwater in the freshwater lens on Roi, compared to only 1.6 x 104 m3 on Namur. We use groundwater samples from a suite of 33 vertically nested monitoring wells, statistical testing, and geochemical modeling using PHREEQC to show that the differences in land-use/land-cover and managed aquifer recharge on Roi and Namur have a statistically significant effect on several groundwater-quality parameters and the controlling geochemical processes. Results also indicate a seven-fold reduction in the dissolution of carbonate rock in the freshwater lens and overlying vadose zone of Roi compared to Namur. Mixing of seawater and the freshwater lens is a more dominant hydrogeochemical process on Roi because of the greater recharge and flushing of the aquifer with freshwater as compared to Namur. In contrast, equilibrium processes and dissolution-precipitation non-equilibrium reactions are more dominant on Namur because of the longer residence times relative to the rate of geochemical reactions. Findings from Roi-Namur Island support selective land-use/land-cover change and

  9. Recommendation in evolving online networks

    Science.gov (United States)

    Hu, Xiao; Zeng, An; Shang, Ming-Sheng

    2016-02-01

    Recommender system is an effective tool to find the most relevant information for online users. By analyzing the historical selection records of users, recommender system predicts the most likely future links in the user-item network and accordingly constructs a personalized recommendation list for each user. So far, the recommendation process is mostly investigated in static user-item networks. In this paper, we propose a model which allows us to examine the performance of the state-of-the-art recommendation algorithms in evolving networks. We find that the recommendation accuracy in general decreases with time if the evolution of the online network fully depends on the recommendation. Interestingly, some randomness in users' choice can significantly improve the long-term accuracy of the recommendation algorithm. When a hybrid recommendation algorithm is applied, we find that the optimal parameter gradually shifts towards the diversity-favoring recommendation algorithm, indicating that recommendation diversity is essential to keep a high long-term recommendation accuracy. Finally, we confirm our conclusions by studying the recommendation on networks with the real evolution data.

  10. Measuring and Modeling Solute Transport in the Rootzone: Protecting the Receiving Water Environments of the Coral Atolls of Tonga

    Science.gov (United States)

    Clothier, B. E.; van der Velde, M.; Green, S. R.; Gee, G. W.; Manu, V.; Menoniti, V.; Vanclooster, M.

    2005-05-01

    Intensification of agriculture on the raised coral atolls of the Tongan archipelago, notably through squash-pumpkin production, has lead to increased use of agrichemicals. Agrichemicals, both fertilisers and pesticides, pose a risk to these fragile environments. Sustainable land-management practices are needed for small-island developing states. On Tongatapu, solutes leaving the rootzone of the squash can rapidly find their way to the underlying freshwater lenses. These lenses are hydraulically linked to the internal lagoon, and the fringing reefs. We have used buried, non-suction fluxmeters to monitor both the quantity and quality of drainage leaving the rootzone of squash. Fertiliser is traditionally applied at planting. During establishment of the squash in 2003, some 350 mm of rain fell, with 70 % of this leaving the rootzone of this permeable soil as drainage. The concentration of nitrate-N in the drainage water was measured at around 50 mg-N/L. All of the initial fertiliser dressing had been lost, along with N mineralised from the plowed-in grass. Pesticides are needed in humid tropical environments to control weeds, pests and diseases. These chemicals can leach though the rootzone to contaminate receiving waters. We modeled the transport and fate of the presticides used in squash production, and we developed a Decision Support Tool (DST). Our DST can be used to select the best pesticides for local conditions, to tailor practices for minimising leaching losses below the rootzone, and to avoid the build-up of residues in the soil. This project, funded by the European Union and NZAID, took a multi-disciplinary approach through measurement and modeling protocols. Our DST enabled us to engage the wider community and stakeholders. There has been increased awareness of the impacts and risks associated with productive land management in the fragile hydrological environments of this small-island developing state.

  11. Uncertainty and variability in updated estimates of potential dose and risk at a US Nuclear Test Site - Bikini Atoll

    International Nuclear Information System (INIS)

    Bogen, K.T.; Conrado, C.L.; Robison, W.L.

    1997-01-01

    Uncertainty and interindividual variability were assessed in estimated doses for a rehabilitation scenario for Bikini Island at Bikini Atoll, in which the top 40 cm of soil would be removed in the housing and village area, and the rest of the island would be treated with potassium fertilizer, prior to an assumed resettlement date of 1999. Doses were estimated for ingested 137 Cs and 90 Sr, external gamma-exposure, and inhalation+ingestion of 241 Am + 239+240 Pu. Two dietary scenarios were considered: imported foods are available (IA); imported foods are unavailable with only local foods consumed (IUA). After ∼5 y of Bikini residence under either IA or IUA assumptions, upper and lower 95% confidence limits on interindividual variability in calculated dose were estimated to lie within a ∼threefold factor of its in population-average value; upper and lower 95% confidence limits on uncertainty in calculated dose were estimated to lie within a ∼twofold factor of its expected value. For reference, the expected values of population-average dose at age 70 y were estimated to be 16 and 52 mSv under IA and IUA dietary assumptions, respectively. Assuming that 200 Bikini resettlers would be exposed to local foods (under both IA and IUA assumptions), the maximum 1-y dose received by any Bikini resident is most likely to be approximately 2 and 8 mSv under the IA and IUA assumptions, respectively. Under the most likely dietary scenario, involving access to imported foods, this analysis indicates that it is most likely that no additional cancer fatalities (above those normally expected) would arise from the increased radiation exposures considered. 33 refs., 4 figs., 4 tabs

  12. Cryptic species obscure introduction pathway of the blue Caribbean sponge (Haliclona (Soestella caerulea, (order: Haplosclerida to Palmyra Atoll, Central Pacific

    Directory of Open Access Journals (Sweden)

    Ingrid S. Knapp

    2015-08-01

    Full Text Available Cryptic species are widespread across the phylum Porifera making the identification of non-indigenous species difficult, an issue not easily resolved by the use of morphological characteristics. The widespread order Haplosclerida is a prime example due to limited and plastic morphological features. Here, we study the reported introduction of Haliclona (Soestella caerulea from the Caribbean to Palmyra Atoll via Hawaiʻi using morphological characteristics and genetic analyses based on one nuclear (18s rDNA and three mitochondrial (COI, the barcoding COI extension (COI ext. and rnl rDNA markers. Despite no clear division in lengths of the oxea spicules between the samples, both mtDNA and nDNA phylogenetic trees supported similar topologies resolving two distinct clades. Across the two clades, the concatenated mtDNA tree resolved twelve subclades, with the COI ext. yielding most of the variability between the samples. Low sequence divergence values (0.68% between two of the subclades indicate that the same species is likely to occur at Palmyra, Hawaiʻi and the Caribbean, supporting the hypothesis that H. caerulea was introduced to Palmyra from the Caribbean, although whether species came directly from the Caribbean to Palmyra or from Hawaiʻi remains unresolved. Conversely, the pattern of highly divergent cryptic species supports the notion that traditionally used spicule measurements are taxonomically unreliable in this group. This study illustrates how understanding the scale of within- as opposed to between-species level genetic variation is critical for interpreting biogeographic patterns and inferring the origins of introduced organisms.

  13. Distribution and sediment production of large benthic foraminifers on reef flats of the Majuro Atoll, Marshall Islands

    Science.gov (United States)

    Fujita, K.; Osawa, Y.; Kayanne, H.; Ide, Y.; Yamano, H.

    2009-03-01

    The distributions and population densities of large benthic foraminifers (LBFs) were investigated on reef flats of the Majuro Atoll, Marshall Islands. Annual sediment production by foraminifers was estimated based on population density data. Predominant LBFs were Calcarina and Amphistegina, and the population densities of these foraminifers varied with location and substratum type on reef flats. Both foraminifers primarily attached to macrophytes, particularly turf-forming algae, and were most abundant on an ocean reef flat (ORF) and in an inter-island channel near windward, sparsely populated islands. Calcarina density was higher on windward compared to leeward sides of ORFs, whereas Amphistegina density was similar on both sides of ORFs. These foraminifers were more common on the ocean side relative to the lagoon side of reef flats around a windward reef island, and both were rare or absent in nearshore zones around reef islands and on an ORF near windward, densely populated islands. Foraminiferal production rates varied with the degree to which habitats were subject to water motion and human influences. Highly productive sites (>103 g CaCO3 m-2 year-1) included an ORF and an inter-island channel near windward, sparsely populated islands, and a seaward area of a reef flat with no reef islands. Low-productivity sites (<10 g CaCO3 m-2 year-1) included generally nearshore zones of lagoonal reef flats, leeward ORFs, and a windward ORF near densely populated islands. These results suggest that the distribution and production of LBFs were largely influenced by a combination of natural environmental factors, including water motion, water depth, elevation relative to the lowest tidal level at spring tide, and the distribution of suitable substratum. The presence of reef islands may limit the distribution and production of foraminifers by altering water circulation in nearshore environments. Furthermore, increased anthropogenic factors (population and activities) may

  14. National Recommended Water Quality Criteria

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Recommended Water Quality Criteria is a compilation of national recommended water quality criteria for the protection of aquatic life and human health...

  15. Recommended Vaccines for Healthcare Workers

    Science.gov (United States)

    ... Vaccination Resources for Healthcare Professionals Recommended Vaccines for Healthcare Workers Recommend on Facebook Tweet Share Compartir On ... for More Information Resources for Those Vaccinating HCWs Healthcare workers (HCWs) are at risk for exposure to ...

  16. Urgent recommendation. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Masayuki [International Affairs and Safeguards Division, Atomic Energy Bureau, Science and Technology Agency, Tokyo (Japan)

    2000-12-01

    The Investigation Committee for Critical Accident at Uranium Processing Plant was founded immediately after the accident to investigate the cause of the accident and to establish measures to prevent the similar accident. On September 30, 1999 around 10:35, the Japan's first criticality accident occurred at JCO Co. Ltd. Uranium processing plant (auxiliary conversion plant) located at Tokai-mura Ibaraki-ken. The criticality continued on and off for approximately 20 hours after the first instantaneous criticality. The accident led the recommendation of tentative evacuation and sheltering indoors for residents living in the neighborhood. The serious exposure to neutrons happened to three workers. The dominant effect is dose due to neutrons and gamma rays from the precipitation tank. When the accident took place, three workers dissolved sequentially about 2.4 kg uranium powder with 18.8 % enrichment in the 10-litter bucket with nitric acid. The procedure of homogenization of uranium nitrate was supposed to be controlled using the shape-limited narrow storage column. Actually, however, the thick and large precipitation tank was used. As a result, about 16.6 kg of uranium was fed into the tank, which presumably caused criticality. The first notification by JCO was delayed and the following communication was not smooth. This led to the delay of correct understanding of the situation and made the initial proper response difficult, then followed by insufficient communication between the nation, prefecture, and local authority. Urgent recommendations were made on the following items; (1) Safety measures to be taken at the accident site, (2) health cares for residents and others, (3) Comprehensive safety securing at nuclear operators such as Establishment of the effective audit system, Safety education for employees and Qualification and licensing system, Safety related documents, etc. (4) Reconstruction of the government's safety regulations such as How safety

  17. Roussely report: recommendations

    International Nuclear Information System (INIS)

    Anon.

    2010-01-01

    A summary of the Roussely report on how to reinforce and support French nuclear industry, has been made public. This report recommends a series of measures. The main measures are: 1) the quick achievement in the best conditions possible of the Olkiluoto plant, 2) to assure the construction of Flamanville-3 under the best conditions of cost and delay, 3) to benefit totally from the feedback experiences of the construction of Olkiluoto and Flamanville-3 for the construction of Penly-3 and of the English program of EPR, 4) to confirm EDF as a leader for French industrial bids proposing nuclear power plants, 5) to diversify the offer of reactors for international bids, 6) to set a common body of rules for all the employees working in the nuclear sector in France, 7) to support the extension of service life of power reactors up to 60 years if safety is not at stake, 8) to promote French safety regulations at an international scale, and 9) to create a university of nuclear engineering. (A.C.)

  18. Site Recommendation Subsurface Layout

    International Nuclear Information System (INIS)

    C.L. Linden

    2000-01-01

    The purpose of this analysis is to develop a Subsurface Facility layout that is capable of accommodating the statutory capacity of 70,000 metric tons of uranium (MTU), as well as an option to expand the inventory capacity, if authorized, to 97,000 MTU. The layout configuration also requires a degree of flexibility to accommodate potential changes in site conditions or program requirements. The objective of this analysis is to provide a conceptual design of the Subsurface Facility sufficient to support the development of the Subsurface Facility System Description Document (CRWMS M andO 2000e) and the ''Emplacement Drift System Description Document'' (CRWMS M andO 2000i). As well, this analysis provides input to the Site Recommendation Consideration Report. The scope of this analysis includes: (1) Evaluation of the existing facilities and their integration into the Subsurface Facility design. (2) Identification and incorporation of factors influencing Subsurface Facility design, such as geological constraints, thermal loading, constructibility, subsurface ventilation, drainage control, radiological considerations, and the Test and Evaluation Facilities. (3) Development of a layout showing an available area in the primary area sufficient to support both the waste inventories and individual layouts showing the emplacement area required for 70,000 MTU and, if authorized, 97,000 MTU

  19. Vertical and horizontal genetic connectivity in Chromis verater, an endemic damselfish found on shallow and mesophotic reefs in the Hawaiian Archipelago and adjacent Johnston Atoll.

    Science.gov (United States)

    Tenggardjaja, Kimberly A; Bowen, Brian W; Bernardi, Giacomo

    2014-01-01

    Understanding vertical and horizontal connectivity is a major priority in research on mesophotic coral ecosystems (30-150 m). However, horizontal connectivity has been the focus of few studies, and data on vertical connectivity are limited to sessile benthic mesophotic organisms. Here we present patterns of vertical and horizontal connectivity in the Hawaiian Islands-Johnston Atoll endemic threespot damselfish, Chromis verater, based on 319 shallow specimens and 153 deep specimens. The mtDNA markers cytochrome b and control region were sequenced to analyze genetic structure: 1) between shallow (shallow and mesophotic populations. There was no significant genetic differentiation by depth, indicating high levels of vertical connectivity between shallow and deep aggregates of C. verater. Consequently, shallow and deep samples were combined by location for analyses of horizontal connectivity. We detected low but significant population structure across the Hawaiian Archipelago (overall cytochrome b: ΦST = 0.009, P = 0.020; control region: ΦST = 0.012, P = 0.009) and a larger break between the archipelago and Johnston Atoll (cytochrome b: ΦST = 0.068, P deep reefs may constitute a population reservoir for species depleted in shallow reef habitats. These findings represent the first connectivity study on a mobile organism that spans shallow and mesophotic depths and provide a reference point for future connectivity studies on mesophotic fishes.

  20. Justification for recommended uncertainties

    International Nuclear Information System (INIS)

    Pronyaev, V.G.; Badikov, S.A.; Carlson, A.D.

    2007-01-01

    -2 MeV are discussed. The extent to which new measurements and evaluation methodologies will lead to revised results that may differ significantly from the presently recommended data is imponderable. While the present standard values are likely to be closer to the truth than earlier versions, and the given errors are reasonably well justified in the context of contemporary data and evaluation methodology, a healthy open minded attitude remains the most sensible approach, consistent with the fundamental spirit of scientific endeavour and enquiry

  1. Recommendation systems in software engineering

    CERN Document Server

    Robillard, Martin P; Walker, Robert J; Zimmermann, Thomas

    2014-01-01

    With the growth of public and private data stores and the emergence of off-the-shelf data-mining technology, recommendation systems have emerged that specifically address the unique challenges of navigating and interpreting software engineering data.This book collects, structures and formalizes knowledge on recommendation systems in software engineering. It adopts a pragmatic approach with an explicit focus on system design, implementation, and evaluation. The book is divided into three parts: "Part I - Techniques" introduces basics for building recommenders in software engineering, including techniques for collecting and processing software engineering data, but also for presenting recommendations to users as part of their workflow.?"Part II - Evaluation" summarizes methods and experimental designs for evaluating recommendations in software engineering.?"Part III - Applications" describes needs, issues and solution concepts involved in entire recommendation systems for specific software engineering tasks, fo...

  2. Recommendation Sets and Choice Queries

    DEFF Research Database (Denmark)

    Viappiani, Paolo Renato; Boutilier, Craig

    2011-01-01

    Utility elicitation is an important component of many applications, such as decision support systems and recommender systems. Such systems query users about their preferences and offer recommendations based on the system's belief about the user's utility function. We analyze the connection between...... the problem of generating optimal recommendation sets and the problem of generating optimal choice queries, considering both Bayesian and regret-based elicitation. Our results show that, somewhat surprisingly, under very general circumstances, the optimal recommendation set coincides with the optimal query....

  3. Classification of Recommender Expertise in the Wikipedia Recommender System

    DEFF Research Database (Denmark)

    Jensen, Christian D.; Pilkauskas, Povilas; Lefévre, Thomas

    2011-01-01

    to the quality of articles. The Wikipedia Recommender System (WRS) was developed to help users determine the credibility of articles based on feedback from other Wikipedia users. The WRS implements a collaborative filtering system with trust metrics, i.e., it provides a rating of articles which emphasizes...... an evaluation of four existing knowledge classification schemes with respect to these requirements. This evaluation helped us identify a classification scheme, which we have implemented in the current version of the Wikipedia Recommender System....... feedback from recommenders that the user has agreed with in the past. This exposes the problem that most recommenders are not equally competent in all subject areas. The first WRS prototype did not include an evaluation of the areas of expertise of recommenders, so the trust metric used in the article...

  4. Classification of Recommender Expertise in the Wikipedia Recommender System

    DEFF Research Database (Denmark)

    Jensen, Christian D.; Pilkauskas, Povilas; Lefevre, Thomas

    2011-01-01

    to the quality of articles. The Wikipedia Recommender System (WRS) was developed to help users determine the credibility of articles based on feedback from other Wikipedia users. The WRS implements a collaborative filtering system with trust metrics, i.e., it provides a rating of articles "which emphasizes...... an evaluation of four existing knowledge classification schemes with respect to these requirements. This evaluation helped us identify a classification scheme, which we have implemented in the current version of the Wikipedia Recommender System....... feedback from recommenders that the user has agreed with in the past. This exposes the problem that most recommenders are not equally competent in all subject areas. The first WRS prototype did not include an evaluation of the areas of expertise of recommenders, so the trust metric used in the article...

  5. Teacher Leadership: Federal Policy Recommendations

    Science.gov (United States)

    Gran, Jackie; Young, Margaret; Broin, Alexandra

    2015-01-01

    This policy brief was developed specifically for federal policymakers, and builds upon the policy recommendations included in "Leading from Every Seat: Empowering Principals to Cultivate Teacher Leadership for School Improvement." The recommendations in this report include the following: (1) Uncover New Leadership Ideas and Seed…

  6. Magnetic susceptibility evolution and sedimentary environments on carbonate platform sediments and atolls, comparison of the Frasnian from Belgium and Alberta, Canada

    Science.gov (United States)

    da Silva, Anne-Christine; Potma, Ken; Weissenberger, John A. W.; Whalen, Michael T.; Humblet, Marc; Mabille, Cédric; Boulvain, Frédéric

    2009-02-01

    Magnetic susceptibility (MS) measurements on carbonate rocks are considered as a proxy for impurities delivered to the carbonate environments. In the absence of strong climatic or tectonic variations, bulk MS values have been linked to sea level variations, because sea-level fall increases clastic supply and therefore increases in magnetic mineral deposition. In this paper we explore the relationship between the average magnitude of bulk MS, with shallowing-up sequences and facies evolution in different Devonian carbonate complexes. Similarities and differences between these parameters have been scrutinized in carbonate attached platform and detached platforms (mounds and/or atolls) from Belgium and Canada. In the carbonate attached platforms from Belgium and Canada, the MS patterns are directly related to depositional environment. Mean MS values increase from the most distal towards the most proximal facies and towards the top of the majority of fourth-order shallowing-up sequences. These trends are in agreement with theoretical background (MS increases with regression). In the Belgian detached platform, the average MS pattern generally shows an opposite behaviour to that observed in the attached carbonate platforms. Average MS decreases towards the most proximal facies and towards the top of a majority of the fourth-order shallowing-up sequences. This behaviour can be explained by the influence of sedimentary rate and water agitation during deposition. A high sedimentary rate will dilute the magnetic minerals in the atoll facies and the high water agitation during deposition may be expected to have prevented the deposition of the magnetic grains. So, the combination of these two effects will result in the observed low values in the atoll crown and lagoonal facies. In the Canadian detached platform, MS is mainly negative. This means that the limestones are very pure. The technique does not appear to be appropriate in these rocks. The variations of average MS

  7. Concurrent Sr/Ca Ratios and Bomb Test 14C Records from a Porites evermanni Colony on Kure Atoll: SST, Climate Change, Ocean Circulation and Management Applications

    Science.gov (United States)

    Covarrubias, S.; Potts, D.; Siciliano, D.; Andrews, A.; Franks, R.

    2013-12-01

    Coral reefs near their latitudinal and ecological limits may be affected disproportionately by global climate changes, especially by changing sea surface temperatures (SST's). One such reef is Kure Atoll, the northernmost reef in the Hawaiian chain. Kure Atoll experiences dramatic temperature and seasonal differences throughout the year. Tracking these fluctuations is important for understanding recent physical forces affecting coral growth in such marginal reefs, and for predicting likely responses to future climate and oceanic changes. We used Sr/Ca ratios of a 50cm Porites evermanni coral core collected in Kure (September 2002) as a SST proxy for reconstructing a temperature timescale spanning the length of the core (~62 years). After cutting a 5 mm thick slab through the center growth axis and X-raying it to identify annual density banding, we extracted 4 equally-spaced samples from each annual increment to quantify, seasonal, inter-annual, and decadal SST patterns. We measured Sr and Ca concentrations by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). We then converted Sr/Ca ratios (mmol/mol) to SST using published equations, and calibrated the more recent SST estimates against satellite-based SST imagery and instrumental records from Midway Atoll (ca. 90 km to SE). We coupled the ICP-OES data with Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) scans along the core to provide higher temporal resolution for interpreting intra-seasonal and inter-seasonal trends. Higher resolution of temperature dating can help us interpret strong inter-seasonal changes not readily seen with low resolution measurements, giving us the ability to track temperature anomalies at interannual and decadal timescales, such as El Niño/Southern Oscillation or La Niña/North Pacific Decadal Oscillation. Further, the SST signature from the Sr/Ca analyses are being used in conjunction with bomb radiocarbon signals in order to establish a complete

  8. USGEO DMWG Cloud Computing Recommendations

    Science.gov (United States)

    de la Beaujardiere, J.; McInerney, M.; Frame, M. T.; Summers, C.

    2017-12-01

    The US Group on Earth Observations (USGEO) Data Management Working Group (DMWG) has been developing Cloud Computing Recommendations for Earth Observations. This inter-agency report is currently in draft form; DMWG hopes to have released the report as a public Request for Information (RFI) by the time of AGU. The recommendations are geared toward organizations that have already decided to use the Cloud for some of their activities (i.e., the focus is not on "why you should use the Cloud," but rather "If you plan to use the Cloud, consider these suggestions.") The report comprises Introductory Material, including Definitions, Potential Cloud Benefits, and Potential Cloud Disadvantages, followed by Recommendations in several areas: Assessing When to Use the Cloud, Transferring Data to the Cloud, Data and Metadata Contents, Developing Applications in the Cloud, Cost Minimization, Security Considerations, Monitoring and Metrics, Agency Support, and Earth Observations-specific recommendations. This talk will summarize the recommendations and invite comment on the RFI.

  9. Recommendation System for Adaptive Learning.

    Science.gov (United States)

    Chen, Yunxiao; Li, Xiaoou; Liu, Jingchen; Ying, Zhiliang

    2018-01-01

    An adaptive learning system aims at providing instruction tailored to the current status of a learner, differing from the traditional classroom experience. The latest advances in technology make adaptive learning possible, which has the potential to provide students with high-quality learning benefit at a low cost. A key component of an adaptive learning system is a recommendation system, which recommends the next material (video lectures, practices, and so on, on different skills) to the learner, based on the psychometric assessment results and possibly other individual characteristics. An important question then follows: How should recommendations be made? To answer this question, a mathematical framework is proposed that characterizes the recommendation process as a Markov decision problem, for which decisions are made based on the current knowledge of the learner and that of the learning materials. In particular, two plain vanilla systems are introduced, for which the optimal recommendation at each stage can be obtained analytically.

  10. Avoiding congestion in recommender systems

    International Nuclear Information System (INIS)

    Ren, Xiaolong; Lü, Linyuan; Liu, Runran; Zhang, Jianlin

    2014-01-01

    Recommender systems use the historical activities and personal profiles of users to uncover their preferences and recommend objects. Most of the previous methods are based on objects’ (and/or users’) similarity rather than on their difference. Such approaches are subject to a high risk of increasingly exposing users to a narrowing band of popular objects. As a result, a few objects may be recommended to an enormous number of users, resulting in the problem of recommendation congestion, which is to be avoided, especially when the recommended objects are limited resources. In order to quantitatively measure a recommendation algorithm's ability to avoid congestion, we proposed a new metric inspired by the Gini index, which is used to measure the inequality of the individual wealth distribution in an economy. Besides this, a new recommendation method called directed weighted conduction (DWC) was developed by considering the heat conduction process on a user–object bipartite network with different thermal conductivities. Experimental results obtained for three benchmark data sets showed that the DWC algorithm can effectively avoid system congestion, and greatly improve the novelty and diversity, while retaining relatively high accuracy, in comparison with the state-of-the-art methods. (paper)

  11. Ingested plastic as a route for trace metals in Laysan Albatross (Phoebastria immutabilis) and Bonin Petrel (Pterodroma hypoleuca) from Midway Atoll.

    Science.gov (United States)

    Lavers, Jennifer L; Bond, Alexander L

    2016-09-15

    Seabirds are declining faster than any other group of birds, with plastic ingestion and associated contaminants linked to negative impacts on marine wildlife, including >170 seabird species. To provide quantitative data on the effects of plastic pollution, we sampled feathers and stomach contents from Laysan Albatross (Phoebastria immutabilis) and Bonin Petrel (Pterodroma hypoleuca) on Midway Atoll, North Pacific Ocean, and assessed our ability to detect change over time by synthesizing previous studies. Between 25 and 100% of fledglings exceed international targets for plastic ingestion by seabirds. High levels of ingested plastic were correlated with increased concentrations of chlorine, iron, lead, manganese, and rubidium in feathers. The frequency of plastic ingestion by Laysan Albatross and concentration of some elements in both species is increasing, suggesting deterioration in the health of the marine environment. Variability in the frequency of plastic ingestion by Laysan Albatross may limit their utility as an indicator species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Space schemes of ecological zonation and morphology of the atolls lagoons and reef complex of an oceanic archipelago of the Caribbean: San Andres and Providence (Colombia)

    International Nuclear Information System (INIS)

    Diaz M, Juan Manuel

    2005-01-01

    The oceanic atolls and reef-complexes of the Archipelago of San Andres and Providencia exhibit semi-enclosed to rather open lagoon basins, where various characteristic bottom habitats occur. Certain areas of the lagoon floor are covered by sediments, being in some settings vegetated by algae or sea grass, and other areas by coralline framework of different types according to the composition and dominance of coral species and to their morphology and level of reef development. This study seeks to determine the spatial distribution patterns of lagoon bottom habitats based on the analysis of gradients of most relevant physical factors. Patterns in the occurrence and abundance of most habitats became evident in relation with wave-energy level, water depth, and the occurrence of islands. Some morphological reef types are oriented in a preferential direction and show spatial arrangements of development that are presumably related to prevailing current speed and direction and wave exposure

  13. Description and epizootiology of Babesia poelea n. sp. in brown boobies (Sula leucogaster (Boddaert)) on Sand Island, Johnston Atoll, Central Pacific

    Science.gov (United States)

    Work, Thierry M.; Rameyer, Robert

    1997-01-01

    We describe a new species of piroplasm from brown boobies (Sula leucogaster) on Sand Island, Johnston Atoll National Wildlife Refuge, central Pacific. Mean parasitemia in adults and chicks was less than 1%, with the parasitemia in chicks significantly greater than in adults. There was no significant relation between the age of chicks and the degree of parasitemia. Parasitized red cells and red cell nuclei were significantly smaller than those of unparasitized cells, and infected birds appeared clinically normal. Prevalence of the parasite in chicks (54%) was significantly greater than in adults (13%), and the geographic distribution of parasitized chicks was skewed toward the eastern end of Sand Island. On the basis of morphologic characteristics, we named it Babesia poelea. The specific name is a concatenation of the Hawaiian names for dark (po'ele) and booby ('a). This is the second documentation of an endemic avian hemoparasite in seabirds from the central Pacific.

  14. The new ICRP general recommendations

    International Nuclear Information System (INIS)

    Sasaki, Y.; Lochard, J.; Holm, L.E.; Niwa, O.; Ishigure, N.; Kosako, T.; Kai, M.

    2007-01-01

    The new draft ICRP recommendations was presented by the ICRP chair, Professor Lars-Eric Holm. His presentation was followed by presentations by Japanese members of the various (CRP committees, discussing their views of the draft recommendations based on their own technical experience. After these presentations, questions from the floor raised many of the key issues of the conference: dose constrains, the LNT hypothesis, dose bands, etc. This showed that the conference participants had carefully and completely read the draft, and were very interested in building a final ICRP recommendation that appropriately addresses all their concerns. These issues were also discussed throughout the entire conference. (author)

  15. Concetration and Distribution of Depleted Uranium (DU) and Beryllium (Be) in Soil and Air on Illeginni Island at Kwajalein Atoll after the Final Land-Impact Test

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W L; Hamilton, T F; Martinelli, R E; Gouveia, F J; Kehl, S R; Lindman, T R; Yakuma, S C

    2010-04-22

    Re-entry vehicles on missiles launched from Vandenberg Air Force base in California re-enter at the Western Test Range, the Regan Test Site (RTS) at Kwajalein Atoll. An Environmental Assessment (EA) was written at the beginning of the program to assess potential impact of DU and Be, the major RV materials of interest from a health and environmental perspective, for both ocean and land impacts. The chemical and structural form of Be and DU in RVs is such that they are insoluble in soil water and seawater. Thus, they are not toxic to plant life on the isalnd (no soil to plant uptake.) Similarly, due to their insolubility in sea water there is no uptake of either element by fish, mollusks, shellfish, sea mammals, etc. No increase in either element has been observed in sea life around Illeginnin Island where deposition of DU and Be has occured. The critical terrestrial exposure pathway for U and Be is inhalation. Concentration of both elements in air over the test period (1989 to 2006) is lower by a factor of nearly 10,000 than the most restrictive U.S. guideline for the general public. Uranium concentrations in air are also lower by factors of 10 to 100 than concentrations of U in air in the U.S. measured by the EPA (Keith et al., 1999). U and Be concentrations in air downwind of deposition areas on Illeginni Island are essentially indistinguishable from natural background concentrations of U in air at the atolls. Thus, there are no health related issues associated with people using the island.

  16. Concetration and Distribution of Depleted Uranium (DU) and Beryllium (Be) in Soil and Air on Illeginni Island at Kwajalein Atoll after the Final Land-Impact Test

    International Nuclear Information System (INIS)

    Robison, W.L.; Hamilton, T.F.; Martinelli, R.E.; Gouveia, F.J.; Kehl, S.R.; Lindman, T.R.; Yakuma, S.C.

    2010-01-01

    Re-entry vehicles on missiles launched from Vandenberg Air Force base in California re-enter at the Western Test Range, the Regan Test Site (RTS) at Kwajalein Atoll. An Environmental Assessment (EA) was written at the beginning of the program to assess potential impact of DU and Be, the major RV materials of interest from a health and environmental perspective, for both ocean and land impacts. The chemical and structural form of Be and DU in RVs is such that they are insoluble in soil water and seawater. Thus, they are not toxic to plant life on the isalnd (no soil to plant uptake.) Similarly, due to their insolubility in sea water there is no uptake of either element by fish, mollusks, shellfish, sea mammals, etc. No increase in either element has been observed in sea life around Illeginnin Island where deposition of DU and Be has occured. The critical terrestrial exposure pathway for U and Be is inhalation. Concentration of both elements in air over the test period (1989 to 2006) is lower by a factor of nearly 10,000 than the most restrictive U.S. guideline for the general public. Uranium concentrations in air are also lower by factors of 10 to 100 than concentrations of U in air in the U.S. measured by the EPA (Keith et al., 1999). U and Be concentrations in air downwind of deposition areas on Illeginni Island are essentially indistinguishable from natural background concentrations of U in air at the atolls. Thus, there are no health related issues associated with people using the island.

  17. Swell-generated Set-up and Infragravity Wave Propagation Over a Fringing Coral Reef: Implications for Wave-driven Inundation of Atoll Islands

    Science.gov (United States)

    Cheriton, O. M.; Storlazzi, C. D.; Rosenberger, K. J.; Quataert, E.; van Dongeren, A.

    2014-12-01

    The Republic of the Marshall Islands is comprised of 1156 islands on 29 low-lying atolls with a mean elevation of 2 m that are susceptible to sea-level rise and often subjected to overwash during large wave events. A 6-month deployment of wave and tide gauges across two shore-normal sections of north-facing coral reef on the Roi-Namur Island on Kwajalein Atoll was conducted during 2013-2014 to quantify wave dynamics and wave-driven water levels on the fringing coral reef. Wave heights and periods on the reef flat were strongly correlated to the water levels. On the fore reef, the majority of wave energy was concentrated in the incident band (5-25 s); due to breaking at the reef crest, however, the wave energy over the reef flat was dominated by infragravity-band (25-250 s) motions. Two large wave events with heights of 6-8 m at 15 s over the fore reef were observed. During these events, infragravity-band wave heights exceeded the incident band wave heights and approximately 1.0 m of set-up was established over the innermost reef flat. This set-up enabled the propagation of large waves across the reef flat, reaching maximum heights of nearly 2 m on the innermost reef flat adjacent to the toe of the beach. XBEACH models of the instrument transects were able to replicate the incident waves, infragravity waves, and wave-driven set-up across the reef when the hydrodynamic roughness of the reef was correctly parameterized. These events led to more than 3 m of wave-driven run-up and inundation of the island that drove substantial morphological change to the beach face.

  18. The Concentration and Distribution of Depleted Uranium (DU) and Beryllium (Be) in Soil and Air on Illeginni Island at Kwajalein Atoll

    International Nuclear Information System (INIS)

    Robison, W L; Hamilton, T F; Martinelli, R E; Gouveia, F J; Lindman, T R; Yakuma, S C

    2006-01-01

    Re-entry vehicles on missiles launched at Vandenberg Air Force base in California re-enter at the Western Test Range, the Regan Test Site (RTS) at Kwajalein Atoll. An environmental Assessment (EA) was written at the beginning of the program to assess potential impact of Depleted Uranium (DU) and Beryllium (Be), the major RV materials of interest from a health and environmental perspective. The chemical and structural form of DU and Be in RVs is such that they are insoluble in soil water and sea water. Consequently, residual concentrations of DU and Be observed in soil on the island are not expected to be toxic to plant life because there is essentially no soil to plant uptake. Similarly, due to their insolubility in sea water there is no uptake of either element by marine biota including fish, mollusks, shellfish and sea mammals. No increase in either element has been observed in sea life around Illeginni Island where deposition of DU and Be has occurred. The critical terrestrial exposure pathway for U and Be is inhalation. Concentration of both elements in air over the test period (1989 to 2006) is lower by a factor of 10,000 than the most restrictive U.S. guideline for the general public. Uranium concentrations in air are also lower by factors of 10 to 100 than concentrations of U in air in the U.S. measured by the EPA (Keith et al., 1999). U and Be concentrations in air downwind of deposition areas on Illeginni Island are essentially indistinguishable from natural background concentrations of U in air at the atolls. Thus, there are no health related issues associated with people using the island

  19. An assessment of non-communicable diseases, diabetes, and related risk factors in the Republic of the Marshall Islands, Kwajelein Atoll, Ebeye Island: a systems perspective.

    Science.gov (United States)

    Ichiho, Henry M; Seremai, Johannes; Trinidad, Richard; Paul, Irene; Langidrik, Justina; Aitaoto, Nia

    2013-05-01

    Non-communicable diseases (NCD) have been declared a health emergency in the US-affiliated Pacific Islands (USAPI). This assessment, funded by the National Institutes of Health, was conducted on Ebeye Island of Kwajelein Atoll, Republic of the Marshall Islands (RMI) to describe the burdens due to selected NCD (diabetes, heart disease, hypertension, stroke, chronic kidney disease); assess the system of service capacity and activities for service delivery, data collection, and reporting; and identify the key issues that need to be addressed. Findings reveal that the risk factors of poor diet, lack of physical activity, and lifestyle behaviors lead to overweight and obesity and subsequent NCD that impact the morbidity and mortality of the population. Population survey of the RMI show that 62.5% of the total population is overweight or obese with a dramatic increase from the 15-24 year old (10.6%) and the 25-64 year old (41.9%) age groups. The leading causes of death were septicemia, renal failure, pneumonia, cancer, and myocardial infarction. Other findings show gaps in the system of administrative, clinical, and support services to address these NCD. All health care in Ebeye is provided in one setting and there is collaboration, coordination, and communication among medical and health care providers. The Book of Protocols for the Kwajalein Atoll Health Care Bureau provides the guidelines, standards, and policy and procedures for the screening, diagnosis, and management of diabetes and other NCDs. Based on these findings, priority issues and problems to be addressed for the administrative, clinical, and data systems were identified.

  20. RECOMMENDER SYSTEMS IN SOCIAL NETWORKS

    Directory of Open Access Journals (Sweden)

    Cleomar Valois Batista Jr

    2011-12-01

    Full Text Available The continued and diversified growth of social networks has changed the way in which users interact with them. With these changes, what once was limited to social contact is now used for exchanging ideas and opinions, creating the need for new features. Users have so much information at their fingertips that they are unable to process it by themselves; hence, the need to develop new tools. Recommender systems were developed to address this need and many techniques were used for different approaches to the problem. To make relevant recommendations, these systems use large sets of data, not taking the social network of the user into consideration. Developing a recommender system that takes into account the social network of the user is another way of tackling the problem. The purpose of this project is to use the theory of six degrees of separation (Watts 2003 amongst users of a social network to enhance existing recommender systems.

  1. From micronutrient recommendations to policy

    DEFF Research Database (Denmark)

    Timotijevic, Lada; Raats, Monique M.; Barnett, Julie

    2010-01-01

    towards achieving a greater link between micronutrient recommendations and behaviour. This study aims to examine the rationale and processes associated with consumer and stakeholder involvement in setting micronutrient recommendations across Europe. Subjects/Methods: Using the contacts established through......Background/Objectives: To achieve the nutritional goals stipulated by micronutrient recommendations, greater attention must be paid to the behavioural routes to such nutritional outcomes. Coopting stakeholders and consumers into decisions regarding micronutrient recommendations is an important step...... countries and its effect on final decisions. Stakeholders were not involved at the outset of the process ('framing' of the problem) in any of the countries, and there was no evidence of consumer involvement and open public fora. Conclusions: Some of the key explanatory factors for diversity in the degree...

  2. Chapter 6: Conclusions and recommendations

    International Nuclear Information System (INIS)

    1995-01-01

    This chapter provides a brief summary of conclusions with respect to project implementation issues. Furthermore, the chapter contains recommendations on future applications of the modelling system and on water resources management in the project area

  3. Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation: January 1980-December 1982

    International Nuclear Information System (INIS)

    Adams, W.H.; Harper, J.A.; Rittmaster, R.S.; Heotis, P.M.; Scott, W.A.

    1984-01-01

    This report updates, for 1980 through 1982, the results of continuing medical surveillance of a Marshallese population accidentally exposed to radioactive fallout in March 1954. The originally exposed Marshallese population comprised 64 persons on Rongelap Atoll who each received, on the average, an estimated 190 rads of absorbed external gamma radiation, 18 on Ailingnae Atoll who received 110 rads, and 159 on Utirik who received 11 rads. There were, in addition, 3 persons in utero on Rongelap, 1 person in utero on Ailingnae, and 8 persons in utero on Utirik who are considered exposed. The recipients of primary medical care include exposed and comparison populations as well as a rather large number of additional beneficiaries who are seen on a humanitarian basis of practical need and resource availability. In recent years, about 1400 people have been seen annually. This report, however, deals with four clearly defined groups: the remaining individuals who were exposed to radioactive fallout on Rongelap, Ailingnae, and Utirik in 1954 (including those in utero), and a comparison population of individuals from Rongelap who were unexposed. The number of persons now in each exposure category are 51, 12, 116, and 137, respectively. 100 references, 4 figures, 5 tables

  4. Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation: January 1980-December 1982

    Energy Technology Data Exchange (ETDEWEB)

    Adams, W.H.; Harper, J.A.; Rittmaster, R.S.; Heotis, P.M.; Scott, W.A.

    1984-01-01

    This report updates, for 1980 through 1982, the results of continuing medical surveillance of a Marshallese population accidentally exposed to radioactive fallout in March 1954. The originally exposed Marshallese population comprised 64 persons on Rongelap Atoll who each received, on the average, an estimated 190 rads of absorbed external gamma radiation, 18 on Ailingnae Atoll who received 110 rads, and 159 on Utirik who received 11 rads. There were, in addition, 3 persons in utero on Rongelap, 1 person in utero on Ailingnae, and 8 persons in utero on Utirik who are considered exposed. The recipients of primary medical care include exposed and comparison populations as well as a rather large number of additional beneficiaries who are seen on a humanitarian basis of practical need and resource availability. In recent years, about 1400 people have been seen annually. This report, however, deals with four clearly defined groups: the remaining individuals who were exposed to radioactive fallout on Rongelap, Ailingnae, and Utirik in 1954 (including those in utero), and a comparison population of individuals from Rongelap who were unexposed. The number of persons now in each exposure category are 51, 12, 116, and 137, respectively. 100 references, 4 figures, 5 tables. (ACR)

  5. TOURISM RECOMMENDATION SYSTEM: EMPIRICAL INVESTIGATION

    OpenAIRE

    Biljana PETREVSKA; Saso KOCESKI

    2012-01-01

    The paper makes an attempt to justify the necessity of implementing recommendation system which will assist tourists in identification of their ideal holiday. The proposed recommendation system based on collaborative filtering notes positive impulses in the case of Macedonia. A software module is developed being capable to generate a personalized list of favorable and tailor-made items. The research outcomes indicate that the designed national tourism web portal can provide satisfactory perfo...

  6. Recommendations

    DEFF Research Database (Denmark)

    Baumeister, Ruth

    2016-01-01

    This article discusses three book publications: C. Kerez: Uncertain Certainty, Tokyo, 2013 H. Hertzberger: Lessons for students in architecture, Rotterdam, 2006, (1991) A. Jorn: Om Formen, Silkeborg, 2014, (1958)......This article discusses three book publications: C. Kerez: Uncertain Certainty, Tokyo, 2013 H. Hertzberger: Lessons for students in architecture, Rotterdam, 2006, (1991) A. Jorn: Om Formen, Silkeborg, 2014, (1958)...

  7. Introduction on health recommender systems.

    Science.gov (United States)

    Sanchez-Bocanegra, C L; Sanchez-Laguna, F; Sevillano, J L

    2015-01-01

    People are looking for appropriate health information which they are concerned about. The Internet is a great resource of this kind of information, but we have to be careful if we don't want to get harmful info. Health recommender systems are becoming a new wave for apt health information as systems suggest the best data according to the patients' needs.The main goals of health recommender systems are to retrieve trusted health information from the Internet, to analyse which is suitable for the user profile and select the best that can be recommended, to adapt their selection methods according to the knowledge domain and to learn from the best recommendations.A brief definition of recommender systems will be given and an explanation of how are they incorporated in the health sector. A description of the main elementary recommender methods as well as their most important problems will also be made. And, to finish, the state of the art will be described.

  8. Hybrid context aware recommender systems

    Science.gov (United States)

    Jain, Rajshree; Tyagi, Jaya; Singh, Sandeep Kumar; Alam, Taj

    2017-10-01

    Recommender systems and context awareness is currently a vital field of research. Most hybrid recommendation systems implement content based and collaborative filtering techniques whereas this work combines context and collaborative filtering. The paper presents a hybrid context aware recommender system for books and movies that gives recommendations based on the user context as well as user or item similarity. It also addresses the issue of dimensionality reduction using weighted pre filtering based on dynamically entered user context and preference of context. This unique step helps to reduce the size of dataset for collaborative filtering. Bias subtracted collaborative filtering is used so as to consider the relative rating of a particular user and not the absolute values. Cosine similarity is used as a metric to determine the similarity between users or items. The unknown ratings are calculated and evaluated using MSE (Mean Squared Error) in test and train datasets. The overall process of recommendation has helped to personalize recommendations and give more accurate results with reduced complexity in collaborative filtering.

  9. Clinical practice recommendations for depression.

    Science.gov (United States)

    Malhi, G S; Adams, D; Porter, R; Wignall, A; Lampe, L; O'Connor, N; Paton, M; Newton, L A; Walter, G; Taylor, A; Berk, M; Mulder, R T

    2009-01-01

    To provide clinically relevant evidence-based recommendations for the management of depression in adults that are informative, easy to assimilate and facilitate clinical decision making. A comprehensive literature review of over 500 articles was undertaken using electronic database search engines (e.g. MEDLINE, PsychINFO and Cochrane reviews). In addition articles, book chapters and other literature known to the authors were reviewed. The findings were then formulated into a set of recommendations that were developed by a multidisciplinary team of clinicians who routinely deal with mood disorders. The recommendations then underwent consultative review by a broader advisory panel that included experts in the field, clinical staff and patient representatives. The clinical practice recommendations for depression (Depression CPR) summarize evidence-based treatments and provide a synopsis of recommendations relating to each phase of the illness. They are designed for clinical use and have therefore been presented succinctly in an innovative and engaging manner that is clear and informative. These up-to-date recommendations provide an evidence-based framework that incorporates clinical wisdom and consideration of individual factors in the management of depression. Further, the novel style and practical approach should promote uptake and implementation.

  10. Personalized recommendation with corrected similarity

    International Nuclear Information System (INIS)

    Zhu, Xuzhen; Tian, Hui; Cai, Shimin

    2014-01-01

    Personalized recommendation has attracted a surge of interdisciplinary research. Especially, similarity-based methods in applications of real recommendation systems have achieved great success. However, the computations of similarities are overestimated or underestimated, in particular because of the defective strategy of unidirectional similarity estimation. In this paper, we solve this drawback by leveraging mutual correction of forward and backward similarity estimations, and propose a new personalized recommendation index, i.e., corrected similarity based inference (CSI). Through extensive experiments on four benchmark datasets, the results show a greater improvement of CSI in comparison with these mainstream baselines. And a detailed analysis is presented to unveil and understand the origin of such difference between CSI and mainstream indices. (paper)

  11. The new ICRP general recommendations

    International Nuclear Information System (INIS)

    Mason, Ch.; Kosako, T.; Kuniyoshi, H.; Kiryu, Y.; Choi, H.S.; Burns, P.A.; Pan, Z.Q.; Xia, Y.

    2007-01-01

    Regulatory views from Japan, South Korea, Australia, China and Indonesia were explained based on their regional context. Some issues, for example 'optimisation', 'dose constrains', 'natural radioactivity', were addressed from the viewpoint of how each country's current regulation system would adopt these new recommendations. It was noted that there would be a need for some flexibility in applying these new recommendations since different countries have different regulatory criteria and benchmarks as well different decision-making processes. It was also noted that definitions and terminologies should be given serious consideration with regard to non-English speaking countries to assure that the new ICRP recommendations are clearly understood, not misinterpreted, easily translated and finally applied in the field of radiation protection. In addition, some recent radiation protection activities, as well as views on utilisation of nuclear power in several countries were presented. (authors)

  12. TOURISM RECOMMENDATION SYSTEM: EMPIRICAL INVESTIGATION

    Directory of Open Access Journals (Sweden)

    Biljana PETREVSKA

    2012-12-01

    Full Text Available The paper makes an attempt to justify the necessity of implementing recommendation system which will assist tourists in identification of their ideal holiday. The proposed recommendation system based on collaborative filtering notes positive impulses in the case of Macedonia. A software module is developed being capable to generate a personalized list of favorable and tailor-made items. The research outcomes indicate that the designed national tourism web portal can provide satisfactory performance and may be of high importance to all key-tourism actors in the process of identifying measures necessary for creating competitive tourism product.

  13. A Two Step Method to Treat Variable Winds in Fallout Smearing Codes.

    Science.gov (United States)

    1982-03-01

    measurement netowrk was modest. However, the southward curvature was verified by data from inhabited atolls (Rongerik and Rongelap) downwind of the...Pi and the American Nuclear Society. Permanent Address: 12 Whipple Street Lewiston, Maine 04240 124 UNCLASSIFIED- SECURITY CLASSIFICATION OF THIS PAGE...Controlling Office) 15. SECURITY CLASS. (of this report) UNCLASSIFIED IS. DECLASStFICATIO’OOWNGRAODHG SCHEDULE 16. DISTRIBUTION STATEMENT (of this

  14. Towards a Legal Recommender System

    NARCIS (Netherlands)

    Winkels, R.; Boer, A.; Vredebregt, B.; van Someren, A.

    2014-01-01

    In this paper we present the results of ongoing research aimed at a legal recommender system where users of a legislative portal receive suggestions of other relevant sources of law, given a focus document. We describe how we make references in case law to legislation explicit and machine readable,

  15. Ubiquitous Multicriteria Clinic Recommendation System.

    Science.gov (United States)

    Chen, Toly

    2016-05-01

    Advancements in information, communication, and sensor technologies have led to new opportunities in medical care and education. Patients in general prefer visiting the nearest clinic, attempt to avoid waiting for treatment, and have unequal preferences for different clinics and doctors. Therefore, to enable patients to compare multiple clinics, this study proposes a ubiquitous multicriteria clinic recommendation system. In this system, patients can send requests through their cell phones to the system server to obtain a clinic recommendation. Once the patient sends this information to the system, the system server first estimates the patient's speed according to the detection results of a global positioning system. It then applies a fuzzy integer nonlinear programming-ordered weighted average approach to assess four criteria and finally recommends a clinic with maximal utility to the patient. The proposed methodology was tested in a field experiment, and the experimental results showed that it is advantageous over two existing methods in elevating the utilities of recommendations. In addition, such an advantage was shown to be statistically significant.

  16. [Organizational recommendations for day surgery].

    Science.gov (United States)

    Bontemps, Gilles

    2014-03-01

    In France, the delayed development of day surgery compared to other countries led the ANAP and the HAS in 2011 to enter into a joint work program to provide some reference guide for hospitals to change their practices to outpatient. In this context, organizational guidelines and operational tools were published in May 2013. The method of construction of the recommendations resulting from an original work that combined a three-fold approach: field vision by identifying the highlights of 15 hospitals selected for their representative performance and analyzing the risks of five voluntary hospitals, mobilization organizational theories from the social sciences, using 53 professional experts. The work concluded on 16 organizational recommendations under four forms (basic principles, strategic elements, operational elements and perspectives). These recommendations are accompanied by tools and guides diagnosis and implementation, as well as productions for further reflection. These organizational recommendations confirmed the specificity of day surgery, which is not related to the act, but to the organization, management and optimization of different flows of a hospital (patient flow, professional flows, logistical, informational…). The performance of a day surgery organization is linked to its ability to control its flow and anticipation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  17. Recommendations for DSD model calculations

    International Nuclear Information System (INIS)

    Cvelbar, F.

    1999-01-01

    The latest achievements of the DSD (direct-semidirect) capture model, such as the extension to unbound final states or to densely distributed bound states, and the introduction of the consistent DSD model are reviewed. Recommendations for the future use of the model are presented. (author)

  18. Recommendations for open data science.

    Science.gov (United States)

    Gymrek, Melissa; Farjoun, Yossi

    2016-01-01

    Life science research increasingly relies on large-scale computational analyses. However, the code and data used for these analyses are often lacking in publications. To maximize scientific impact, reproducibility, and reuse, it is crucial that these resources are made publicly available and are fully transparent. We provide recommendations for improving the openness of data-driven studies in life sciences.

  19. Recommendations for Institutional Prematriculation Immunizations

    Science.gov (United States)

    Journal of American College Health, 2011

    2011-01-01

    The recommendations presented in this article are provided to colleges and universities to facilitate the implementation of a comprehensive institutional prematriculation immunization policy. Vaccine-preventable diseases continue to occur on American campuses. In response to changing epidemiology and the introduction of new vaccines, the ACHA…

  20. A Flexible Electronic Commerce Recommendation System

    Science.gov (United States)

    Gong, Songjie

    Recommendation systems have become very popular in E-commerce websites. Many of the largest commerce websites are already using recommender technologies to help their customers find products to purchase. An electronic commerce recommendation system learns from a customer and recommends products that the customer will find most valuable from among the available products. But most recommendation methods are hard-wired into the system and they support only fixed recommendations. This paper presented a framework of flexible electronic commerce recommendation system. The framework is composed by user model interface, recommendation engine, recommendation strategy model, recommendation technology group, user interest model and database interface. In the recommender strategy model, the method can be collaborative filtering, content-based filtering, mining associate rules method, knowledge-based filtering method or the mixed method. The system mapped the implementation and demand through strategy model, and the whole system would be design as standard parts to adapt to the change of the recommendation strategy.

  1. Evaluating the potential for near-shore bathymetry on the Majuro Atoll, Republic of the Marshall Islands, using Landsat 8 and WorldView-3 imagery

    Science.gov (United States)

    Poppenga, Sandra K.; Palaseanu-Lovejoy, Monica; Gesch, Dean B.; Danielson, Jeffrey J.; Tyler, Dean J.

    2018-04-16

    Satellite-derived near-shore bathymetry (SDB) is becoming an increasingly important method for assessing vulnerability to climate change and natural hazards in low-lying atolls of the northern tropical Pacific Ocean. Satellite imagery has become a cost-effective means for mapping near-shore bathymetry because ships cannot collect soundings safely while operating close to the shore. Also, green laser light detection and ranging (lidar) acquisitions are expensive in remote locations. Previous research has demonstrated that spectral band ratio-based techniques, commonly called the natural logarithm approach, may lead to more precise measurements and modeling of bathymetry because of the phenomenon that different substrates at the same depth have approximately equal ratio values. The goal of this research was to apply the band ratio technique to Landsat 8 at-sensor radiance imagery and WorldView-3 atmospherically corrected imagery in the coastal waters surrounding the Majuro Atoll, Republic of the Marshall Islands, to derive near-shore bathymetry that could be incorporated into a seamless topobathymetric digital elevation model of Majuro. Attenuation of light within the water column was characterized by measuring at-sensor radiance and reflectance at different depths and calculating an attenuation coefficient. Bathymetric lidar data, collected by the U.S. Naval Oceanographic Office in 2006, were used to calibrate the SDB results. The bathymetric lidar yielded a strong linear relation with water depths. The Landsat 8-derived SDB estimates derived from the blue/green band ratio exhibited a water attenuation extinction depth of 6 meters with a coefficient of determination R2=0.9324. Estimates derived from the coastal/red band ratio had an R2=0.9597. At the same extinction depth, SDB estimates derived from WorldView-3 imagery exhibited an R2=0.9574. Because highly dynamic coastal shorelines can be affected by erosion, wetland loss, hurricanes, sea-level rise, urban

  2. The radiological situation at the atolls of Mururoa and Fangataufa. Technical report. V. 5. Transport of radioactive material within the marine environment

    International Nuclear Information System (INIS)

    1998-08-01

    The report discusses the modeling of the transport of radionuclides through the marine environment after their release from the atolls of Mururoa and Fangataufa. Modeling included mixing within the lagoons, and transport to the shores of neighbouring islands and distant continents of radioactive material released into the lagoons from sediments and from underground sources (from discharge directly to the ocean through the flanks of the carbonate caps of the atolls). For the purposes of the modelling, the area around the source of radioactivity (i.e. the point at which radionuclides are released into the marine environment) was divided into three major zones: a) the near field (the lagoons); b) the regional field (broadly, the area of French Polynesia); and c) the far field (the South Pacific beyond the regional field). The methodology adopted in this study can be summarized as follows: 1. A model of the mixing of water in the lagoons was developed. This model was used to estimate the radionuclide concentrations in the lagoons for given releases into the lagoons, and the flow rates of radionuclides from the lagoons into the surrounding ocean. 2. The release rates of radionuclides from the lagoon sediments were assessed, leading to estimates of the release rates of plutonium 137 Cs, 90 Sr and tritium from the lagoons to the oceans as a function of time. 3. A model was developed to predict the movement of sediment between the lagoons and the ocean. Estimates were made of the amount of sediment, and the corresponding quantity of plutonium leaving the lagoons annually under average weather conditions, or as consequence of a severe storm. 4. Three compartment models were used to model dispersion of radionuclides in the regional field. These models cover different areas with different resolutions, and each has particular strengths and weaknesses. Taken together, they give an indication of the likely uncertainty in the dispersion estimates, and improve the robustness of

  3. Radionuclide characterization and associated dose from long-lived radionuclides in close-in fallout delivered to the marine environment at Bikini and Enewetak Atolls

    International Nuclear Information System (INIS)

    Robison, W.L.; Noshkin, V.E.

    1999-01-01

    Between June 1946 and October 1958, Enewetak and Bikini Atolls were used by the US as testing grounds for 66 nuclear devices. The combined explosive yield from these tests was 107 million t (million t TNT equivalents). This testing produced close-in fallout debris that was contaminated with quantities of radioactive fission and particle activated products, and unspent radioactive nuclear fuel that entered the aquatic environment of the atolls. Today, the sediments in the lagoons are reservoirs for tens of TBq of the transuranics and some long-lived fission and activation products. The larger amounts of contamination are associated with fine and coarse sediment material adjacent to the locations of the high yield explosions. Radionuclides are also distributed vertically in the sediment column to various depths in all regions of the lagoons. Concentrations greater than fallout background levels are found in filtered water sampled over several decades from all locations and depths in the lagoons. This is a direct indication that the radionuclides are continuously mobilized to solution from the solid phases. Of particular importance is the fact that the long-lived radionuclides are accumulated to different levels by indigenous aquatic plants and organisms that are used as food by resident people. One might anticipate finding continuous high contamination levels in many of the edible marine organisms from the lagoons, since the radionuclides associated with the sediments are not contained and are available to the different organisms in a relatively shallow water environment. This is not the case. We estimate that the radiological dose from consumption of the edible parts of marine foods at Enewetak and Bikini is presently approximately 0.05% of the total 50-year integral effective dose from all other exposure pathways that include ingestion of terrestrial foods and drinking water, external exposure and inhalation. The total radiological dose from the marine pathway is

  4. Radionuclide characterization and associated dose from long-lived radionuclides in close-in fallout delivered to the marine environment at Bikini and Enewetak Atoll

    International Nuclear Information System (INIS)

    Noshkin, V. E.; Robison, W. L.

    1998-01-01

    Between June 1946 and October 1958, Enewetak and Bikini Atolls were used by the United States as testing grounds for 66 nuclear devices. The combined explosive yield from these tests was 107 Mt (Mt TNT equivalents). This testing produced close-in fallout debris that was contaminated with quantities of radioactive fission and particle activated products, and unspent radioactive nuclear fuel that entered the aquatic environment of the atolls. Today, the sediments in the lagoons are reservoirs for 10's of TBq of the transuranics and some long-lived fission and activation products. The larger amounts of contamination are associated with fine and coarse sediment material adjacent to the locations of the high yield explosions. Radionuclides are also distributed vertically in the sediment column to various depths in all regions of the lagoons. Concentrations greater than fallout background levels are found in filtered water sampled over several decades from all locations and depths in the lagoons. This is a direct indication that the radionuclides are continuously mobilized to solution from the solid phases. Of particular importance is the fact that the long-lived radionuclides are accumulated to different levels by indigenous aquatic plants and organisms that are used as food by resident people. One might anticipate finding continuous high contamination levels in many of the edible marine organisms from the lagoons, since the radionuclides associated with the sediments are not contained and are available to the different organisms in a relatively shallow water environment. This is not the case. We estimate that the radiological dose from consumption of the edible parts of marine foods at Enewetak and Bikini is presently about 0.05% of the total 50-year integral effective dose from all other exposure pathways that include ingestion of terrestrial foods and drinking water, external exposure and inhalation. The total radiological dose from the marine pathway is dominated by

  5. Sediment studies at Bikini Atoll part 3. Inventories of some long-lived gamma-emitting radionuclides associated with lagoon surface sediments

    Energy Technology Data Exchange (ETDEWEB)

    Noshkin, V.E.

    1997-12-01

    Surface sediment samples were collected during 1979 from 87 locations in the lagoon at Bikini Atoll. The collections were made to better define the concentrations and distribution of long-lived radionuclides associated with the bottom material and to show what modifications occurred to the composition of the surface sediment from the nuclear testing program conducted by the United States at the Atoll between 1946 and 1958. This is the last of three reports on Bikini sediment studies. In this report, we discuss the concentrations and inventories of the residual long-lived gamma-emitting radionuclides in sediments from the lagoon. The gamma-emitting radionuclides detected most frequently in sediments collected in 1979, in addition to Americium-241 ({sup 241}Am) (discussed in the second report of this series), included Cesium-137 ({sup 137}Cs), Bismuth-207 ({sup 207}Bi), Europium-155 ({sup 155}Eu), and Cobalt-60 ({sup 60}Co). Other man-made, gamma-emitting radionuclides such as Europium-152,154 ({sup 152,154}Eu), Antimony-125 ({sup 125}Sb), and Rhodium-101,102m ({sup 101,102m}Rh) were occasionally measured above detection limits in sediments near test site locations. The mean inventories for {sup 137}Cs, {sup 207}Ei, {sup 155}Eu, and {sup 60}Co in the surface 4 cm of the lagoon sediment to be 1.7, 0.56, 7.76, and 0.74 TBq, respectively. By June 1997, radioactive decay would reduce these values to 1.1, 0.38, 0.62, and 0.07 TBq, respectively. Some additional loss results from a combination of different processes that continuously mobilize and return some amount of the radionuclides to the water column. The water and dissolved constituents are removed from the lagoon through channels and exchange with the surface waters of the north equatorial Pacific Ocean. Highest levels of these radionuclides are found in surface deposits lagoonward of the Bravo Crater. Lowest concentrations and inventories are associated with sediment lagoonward of the eastern reef. The quantities in

  6. RARD: The Related-Article Recommendation Dataset

    OpenAIRE

    Beel, Joeran; Carevic, Zeljko; Schaible, Johann; Neusch, Gabor

    2017-01-01

    Recommender-system datasets are used for recommender-system evaluations, training machine-learning algorithms, and exploring user behavior. While there are many datasets for recommender systems in the domains of movies, books, and music, there are rather few datasets from research-paper recommender systems. In this paper, we introduce RARD, the Related-Article Recommendation Dataset, from the digital library Sowiport and the recommendation-as-a-service provider Mr. DLib. The dataset contains ...

  7. Scientific and educational recommender systems

    Science.gov (United States)

    Guseva, A. I.; Kireev, V. S.; Bochkarev, P. V.; Kuznetsov, I. A.; Philippov, S. A.

    2017-01-01

    This article discusses the questions associated with the use of reference systems in the preparation of graduates in physical function. The objective of this research is creation of model of recommender system user from the sphere of science and education. The detailed review of current scientific and social network for scientists and the problem of constructing recommender systems in this area. The result of this study is to research user information model systems. The model is presented in two versions: the full one - in the form of a semantic network, and short - in a relational form. The relational model is the projection in the form of semantic network, taking into account the restrictions on the amount of bonds that characterize the number of information items (research results), which interact with the system user.

  8. Finding and Recommending Scholarly Articles

    Science.gov (United States)

    Kurtz, Michael J.; Henneken, Edwin A.

    2014-05-01

    The rate at which scholarly literature is being produced has been increasing at approximately 3.5 percent per year for decades. This means that during a typical 40 year career the amount of new literature produced each year increases by a factor of four. The methods scholars use to discover relevant literature must change. Just like everybody else involved in information discovery, scholars are confronted with information overload. Two decades ago, this discovery process essentially consisted of paging through abstract books, talking to colleagues and librarians, and browsing journals. A time-consuming process, which could even be longer if material had to be shipped from elsewhere. Now much of this discovery process is mediated by online scholarly information systems. All these systems are relatively new, and all are still changing. They all share a common goal: to provide their users with access to the literature relevant to their specific needs. To achieve this each system responds to actions by the user by displaying articles which the system judges relevant to the user's current needs. Recently search systems which use particularly sophisticated methodologies to recommend a few specific papers to the user have been called "recommender systems". These methods are in line with the current use of the term "recommender system" in computer science. We do not adopt this definition, rather we view systems like these as components in a larger whole, which is presented by the scholarly information systems themselves. In what follows we view the recommender system as an aspect of the entire information system; one which combines the massive memory capacities of the machine with the cognitive abilities of the human user to achieve a human-machine synergy.

  9. Group Recommendation in Social Networks

    Science.gov (United States)

    2011-01-01

    interests 8,822,921 DOUBAN Largest Chinese community providing user review and recommendation services for movies, books, and music . It also...doubles up as the Chinese language book, movie and music database. 46,850,000 FACEBOOK General 750,000,000+ FLIXSTER Movies 32,000,000 FOURSQUARE...groups, events and community pages) • More than 30 billion pieces of content (web links, news stories, blog posts, notes, photo albums , etc.) shared

  10. Workers and the ICRP recommendations

    International Nuclear Information System (INIS)

    Zerbib, J.C.

    1979-01-01

    In both the preparation and the application of the recommendations presented by the ICRP one important voice has been absent: that of the workers in the nuclear industry. A large number of specialists are studying their situation from all points of view, in their different capacities as workers, consumers and male or female members of the public, but this extensive study is being done without consulting them, without their opinion even being asked for. The paper discusses such deficiencies, in particular all those aspects which distinguish these recommendations from a legal text. The lack of conciseness in the definition of the limit which the average annual dose to a large group of workers must not exceed (500 mrad) is considered. The possibility of a large number of workers being exposed for a long period is not acceptable if the decision is left to the manager of a nuclear facility alone. Cost-benefit analysis, as it is described in the ICRP text, cannot be considered to provide credible protection from the point of view of workers. Moreover, the various ICRP recommendations fail to mention such important matters as allowance for low-dose effects, disparities in the social security coverage offered to various categories of workers in the event of occupational illness, and the increasing use of migrant workers for difficult decontamination and maitenance tasks. At a time when it is thought that nuclear technology can be standardized, the French Democratic Labour Confederation (CFDT) expresses its fears concerning the practical application of the ICRP recommendations; for example, the text of ICRP Publication 26 has not yet been translated into French, but Euratom has already proposed directives for its application in Member States

  11. Recommended HSE-7 documents hierarchy

    International Nuclear Information System (INIS)

    Klein, R.B.; Jennrich, E.A.; Lund, D.M.; Danna, J.G.; Davis, K.D.; Rutz, A.C.

    1990-01-01

    This report recommends a hierarchy of waste management documents at Los Alamos National Laboratory (LANL or ''Laboratory''). The hierarchy addresses documents that are required to plan, implement, and document waste management programs at Los Alamos. These documents will enable the waste management group and the six sections contained within that group to satisfy requirements that are imposed upon them by the US Department of Energy (DOE), DOE Albuquerque Operations, US Environmental Protection Agency, various State of New Mexico agencies, and Laboratory management

  12. Paris convention - Decisions, recommendations, interpretations

    International Nuclear Information System (INIS)

    1990-01-01

    This booklet is published in a single edition in English and French. It contains decisions, recommendations and interpretations concerning the 1960 Paris Convention on Third Party Liability in the Field of Nuclear Energy adopted by the OECD Steering Committee and the OECD Council. All the instruments are set out according to the Article of the Convention to which they relate and explanatory notes are added where necessary [fr

  13. Aggregated recommendation through random forests.

    Science.gov (United States)

    Zhang, Heng-Ru; Min, Fan; He, Xu

    2014-01-01

    Aggregated recommendation refers to the process of suggesting one kind of items to a group of users. Compared to user-oriented or item-oriented approaches, it is more general and, therefore, more appropriate for cold-start recommendation. In this paper, we propose a random forest approach to create aggregated recommender systems. The approach is used to predict the rating of a group of users to a kind of items. In the preprocessing stage, we merge user, item, and rating information to construct an aggregated decision table, where rating information serves as the decision attribute. We also model the data conversion process corresponding to the new user, new item, and both new problems. In the training stage, a forest is built for the aggregated training set, where each leaf is assigned a distribution of discrete rating. In the testing stage, we present four predicting approaches to compute evaluation values based on the distribution of each tree. Experiments results on the well-known MovieLens dataset show that the aggregated approach maintains an acceptable level of accuracy.

  14. Efficient Tensor Strategy for Recommendation

    Directory of Open Access Journals (Sweden)

    Aboagye Emelia Opoku

    2017-07-01

    Full Text Available The era of big data has witnessed the explosion of tensor datasets, and large scale Probabilistic Tensor Factorization (PTF analysis is important to accommodate such increasing trend of data. Sparsity, and Cold-Start are some of the inherent problems of recommender systems in the era of big data. This paper proposes a novel Sentiment-Based Probabilistic Tensor Analysis technique senti-PTF to address the problems. The propose framework first applies a Natural Language Processing technique to perform sentiment analysis taking advantage of the huge sums of textual data generated available from the social media which are predominantly left untouched. Although some current studies do employ review texts, many of them do not consider how sentiments in reviews influence recommendation algorithm for prediction. There is therefore this big data text analytics gap whose modeling is computationally expensive. From our experiments, our novel machine learning sentiment-based tensor analysis is computationally less expensive, and addresses the cold-start problem, for optimal recommendation prediction.

  15. Vaccination recommended for pregnant women

    Directory of Open Access Journals (Sweden)

    Justyna Magdalena Skolarczyk

    2017-04-01

    Full Text Available A vaccine is a formulation of biological origin that contains substances capable of inducing immune processes without the ability to cause a disease. Vaccination is considered the best mean to prevent infectious diseases and their serious complications. Vaccination of a pregnant women can provide protection against severe infectious diseases of both pregnant women and their children. The aim of the study is to present currently available types of vaccines recommended for pregnant women and indications for their use by analyzing the data available in the PubMed, and Medline electronic databases. In the United States, vaccination recommendations for pregnant women include inactivated influenza vaccine and tetanus and diphtheria toxoid vaccine (Tdap. In some countries, pregnant women also receive a vaccine against hepatitis B as well as anti hepatitis A and E. There are also studies on vaccines against the RSV virus and pneumococci. Vaccination is the most effective form of prevention of infectious diseases and their use during pregnancy does not entail any additional risk to the mother or her baby. The benefits of vaccination are huge, so pregnant women should take  recommended vaccination and shouldn’t  be afraid of using them.

  16. The zebrafish maternal-effect gene cellular atoll encodes the centriolar component sas-6 and defects in its paternal function promote whole genome duplication.

    Science.gov (United States)

    Yabe, Taijiro; Ge, Xiaoyan; Pelegri, Francisco

    2007-12-01

    A female-sterile zebrafish maternal-effect mutation in cellular atoll (cea) results in defects in the initiation of cell division starting at the second cell division cycle. This phenomenon is caused by defects in centrosome duplication, which in turn affect the formation of a bipolar spindle. We show that cea encodes the centriolar coiled-coil protein Sas-6, and that zebrafish Cea/Sas-6 protein localizes to centrosomes. cea also has a genetic paternal contribution, which when mutated results in an arrested first cell division followed by normal cleavage. Our data supports the idea that, in zebrafish, paternally inherited centrosomes are required for the first cell division while maternally derived factors are required for centrosomal duplication and cell divisions in subsequent cell cycles. DNA synthesis ensues in the absence of centrosome duplication, and the one-cycle delay in the first cell division caused by cea mutant sperm leads to whole genome duplication. We discuss the potential implications of these findings with regards to the origin of polyploidization in animal species. In addition, the uncoupling of developmental time and cell division count caused by the cea mutation suggests the presence of a time window, normally corresponding to the first two cell cycles, which is permissive for germ plasm recruitment.

  17. The flip-or-flop boutique: Marine debris on the shores of St Brandon's rock, an isolated tropical atoll in the Indian Ocean.

    Science.gov (United States)

    Bouwman, Hindrik; Evans, Steven W; Cole, Nik; Choong Kwet Yive, Nee Sun; Kylin, Henrik

    2016-03-01

    Isolated coral atolls are not immune from marine debris accumulation. We identified Southeast Asia, the Indian sub-continent, and the countries on the Arabian Sea as most probable source areas of 50 000 items on the shores of St. Brandon's Rock (SBR), Indian Ocean. 79% of the debris was plastics. Flip-flops, energy drink bottles, and compact fluorescent lights (CFLs) were notable item types. The density of debris (0.74 m(-)(1) shore length) is comparable to similar islands but less than mainland sites. Intact CFLs suggests product-facilitated long-range transport of mercury. We suspect that aggregated marine debris, scavenged by the islands from currents and gyres, could re-concentrate pollutants. SBR islets accumulated debris types in different proportions suggesting that many factors act variably on different debris types. Regular cleaning of selected islets will take care of most of the accumulated debris and may improve the ecology and tourism potential. However, arrangements and logistics require more study. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Tidal flushing and wind driven circulation of Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia) from in situ observations and numerical modelling

    International Nuclear Information System (INIS)

    Dumas, F.; Le Gendre, R.; Thomas, Y.; Andréfouët, S.

    2012-01-01

    Hydrodynamic functioning and water circulation of the semi-closed deep lagoon of Ahe atoll (Tuamotu Archipelago, French Polynesia) were investigated using 1 year of field data and a 3D hydrodynamical model. Tidal amplitude averaged less than 30 cm, but tide generated very strong currents (2 m s −1 ) in the pass, creating a jet-like circulation that partitioned the lagoon into three residual circulation cells. The pass entirely flushed excess water brought by waves-induced radiation stress. Circulation patterns were computed for climatological meteorological conditions and summarized with stream function and flushing time. Lagoon hydrodynamics and general overturning circulation was driven by wind. Renewal time was 250 days, whereas the e-flushing time yielded a lagoon-wide 80-days average. Tide-driven flush through the pass and wind-driven overturning circulation designate Ahe as a wind-driven, tidally and weakly wave-flushed deep lagoon. The 3D model allows studying pearl oyster larvae dispersal in both realistic and climatological conditions for aquaculture applications.

  19. Climatic Constraints on Growth Rate and Geochemistry (Sr/Ca and U/Ca) of the Coral Siderastrea stellata in the Southwest Equatorial Atlantic (Rocas Atoll, Brazil)

    Science.gov (United States)

    Evangelista, H.; Sifeddine, A.; Corrège, T.; Servain, J.; Dassié, E. P.; Logato, R.; Cordeiro, R. C.; Shen, C.-C.; Le Cornec, F.; Nogueira, J.; Segal, B.; Castagna, A.; Turcq, B.

    2018-03-01

    Although relatively rare compared to similar latitudes in the Pacific or Indian Oceans, massive coral colonies are present in the Tropical/Equatorial Southwestern Atlantic Ocean. However, detailed geochemical compositions of these corals are still largely unknown. In this work, we present growth rates, Sr/Ca, and U/Ca ratios of the coral colony (Siderastrea stellata) sampled at Rocas Atoll, off the Brazilian coast. These variables are primarily affected by sea surface temperature (SST) at seasonal scale, and by wind stress at interannual scale, these results represent a broad new finding. A lower significance at the interannual time scale between Sr/Ca and U/Ca with respect to SST is attributed to the low SST amplitude closed to Equator. An investigation on the dependence of coral growth rates with respect to the "cloud shading effect" promoted by the Intertropical Convergence Zone (ITCZ) does not show significant influence. Additionally, rain seems to act on local geochemistry of Sr/Ca ratios and growth rate at the decadal scale.

  20. Commercial Appropriation of a Person's Image: Wells V Atoll Media (Pty Ltd (Unreported 11961/2006 [2009] ZAWCHC 173 (9 November 2009

    Directory of Open Access Journals (Sweden)

    SJ Cornelius

    2011-05-01

    Full Text Available Our modern society has become transfixed with celebrity. Business people and marketers also endeavour to cash in on the popularity enjoyed by the stars and realise the value of associating merchandise or trademarks with the rich and famous. This leads to difficulties when the attributes of a person are apparently used without consent, which poses new questions to the law: should the law protect the individual against the unlawful use of his or her image? If so, to what extent should such protection be granted? These were some of the questions which the court had to answer in Wells v Atoll Media (Pty. The judgment in Wells has redefined the right to identity and provided some clarity on what the infringement of that right would amount to. When the attributes of a person are used without consent, the right to identity can be violated in one of four ways. A person's right to identity can be infringed upon if the attributes of that person are used without permission in a way which cannot be reconciled with the true image of the individual concerned, if the use amounts to the commercial exploitation of the individual, if it cannot be reconciled with generally accepted norms of decency, or if it violates the privacy of that person.

  1. Better or worse? The role of solar photovoltaic (PV) systems in sustainable development. Case studies of remote atoll communities in Kiribati

    Energy Technology Data Exchange (ETDEWEB)

    Mala, Kirti; Schlaepfer, August; Pryor, Trevor [School of Electrical, Energy and Process Engineering, Murdoch University, Murdoch 6150 (Australia)

    2009-02-15

    The Republic of Kiribati, formerly known as the Gilbert Islands, is a Micronesian (One of the three groups of islands in the Pacific. The eight territories that make up Micronesia are Commonwealth of the Northern Mariana Islands, Federated States of Micronesia, Republic of Kiribati, Republic of the Marshall Islands, Republic of Nauru, Republic of Palau, Territory of Guam and Territory of Wake Island. The other two groups of islands in the Pacific are Melanesia and Polynesia) country in the Pacific. The energy sources utilised in Kiribati include petroleum products, biomass, solar energy and wind power. Solar energy was introduced in Kiribati in the early 1980s (Wade H. Survey of RESCO projects - prepared for OPRET, Fiji Department of Energy, 2003; p. 36). Currently, it makes a very insignificant (less than 1%) contribution to the total annual primary energy supply (South Pacific Regional Environment Programme (SPREP). Pacific Islands Renewable Energy Project (PIREP) - Pacific Regional Energy Assessment (PREA) 2004. Kiribati national report, Vol. 5, 2005). Solar energy in Kiribati is used mostly in the form of solar photovoltaic (PV) technologies for the provision of lighting and electricity. This study examines the role of PV technologies in the sustainable development process in Kiribati, with particular reference to remote atoll communities. Initial results from on-site surveys carried out are reported in this paper. These surveys have sought to identify the reasons why people use or do not use PV systems. (author)

  2. Towards Information Enrichment through Recommendation Sharing

    Science.gov (United States)

    Weng, Li-Tung; Xu, Yue; Li, Yuefeng; Nayak, Richi

    Nowadays most existing recommender systems operate in a single organisational basis, i.e. a recommender system recommends items to customers of one organisation based on the organisation's datasets only. Very often the datasets of a single organisation do not have sufficient resources to be used to generate quality recommendations. Therefore, it would be beneficial if recommender systems of different organisations with similar nature can cooperate together to share their resources and recommendations. In this chapter, we present an Ecommerce-oriented Distributed Recommender System (EDRS) that consists of multiple recommender systems from different organisations. By sharing resources and recommendations with each other, these recommenders in the distributed recommendation system can provide better recommendation service to their users. As for most of the distributed systems, peer selection is often an important aspect. This chapter also presents a recommender selection technique for the proposed EDRS, and it selects and profiles recommenders based on their stability, average performance and selection frequency. Based on our experiments, it is shown that recommenders' recommendation quality can be effectively improved by adopting the proposed EDRS and the associated peer selection technique.

  3. Dietetic recommendations in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    María Rosa Alhambra-Expósito

    2013-12-01

    Full Text Available Rheumatoid arthritis (RA is a chronic autoimmune disease that has a significant effect on patients’ physical, emotional, and social functioning. For decades, patients have used different diets to try to improve the symptoms of RA. The possible benefits of dietary therapy for rheumatoid arthritis are reviewed in this article. Nutritional objectives for RA, are to halt the loss of bone mass, promote healing of bone fractures and improving bone-associated inflammatory disorders and joints. In general, diets low in saturated fat, rich in polyunsaturated fats: omega 3 and omega 6, rich in complex carbohydrates and fiber are recommended.

  4. Vaccination recommended for pregnant women

    OpenAIRE

    Skolarczyk, Justyna; Łabądź, Dawid; Pekar, Joanna; Nieradko-Iwanicka, Barbara

    2017-01-01

    Skolarczyk Justyna, Łabądź Dawid, Pekar Joanna, Nieradko-Iwanicka Barbara. Vaccination recommended for pregnant women. Journal of Education, Health and Sport. 2017;7(4):682-688. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.569050 http://ojs.ukw.edu.pl/index.php/johs/article/view/4423 The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 1223 (26.01.2017). 1223 Journal of Education, Health and Sport eI...

  5. ExpertFOAF recommends experts

    DEFF Research Database (Denmark)

    Iofcu, Tereza; Diederich, Joerg; Dolog, Peter

    2007-01-01

    FOAF files are often used for publishing simple information about persons and about their community. Our proposal is to extend the user's FOAF files with automatically generated user profiles, which are based on a histogram of the user's interest and which are also semantically enriched using...... recommender systems for finding users with similar interests and, hence, expertise in different domains. We consider a well-defined user profile to express best the user's current interests in a domain, where the domain (such as the research environment with students and professors) is defined by a collection...

  6. Physical Exercise and MS Recommendations

    DEFF Research Database (Denmark)

    Dalgas, U; Ingemann-Hansen, T; Stenager, E

    2009-01-01

    in a number of physiological functions, which ultimately can lead to functional improvements that have a positive effect on a patients daily life. The purpose of this review is, based on the existing research, to provide clinicians with some easily administrable recommendations for the application of exercise......The use of physical exercise programmes in the rehabilitation of patients with multiple sclerosis (MS) has been a controversial issue for many years. During the last decade, however, evidence from a number of studies has suggested that exercise is a safe and efficient way to induce improvements...

  7. Hybrid employment recommendation algorithm based on Spark

    Science.gov (United States)

    Li, Zuoquan; Lin, Yubei; Zhang, Xingming

    2017-08-01

    Aiming at the real-time application of collaborative filtering employment recommendation algorithm (CF), a clustering collaborative filtering recommendation algorithm (CCF) is developed, which applies hierarchical clustering to CF and narrows the query range of neighbour items. In addition, to solve the cold-start problem of content-based recommendation algorithm (CB), a content-based algorithm with users’ information (CBUI) is introduced for job recommendation. Furthermore, a hybrid recommendation algorithm (HRA) which combines CCF and CBUI algorithms is proposed, and implemented on Spark platform. The experimental results show that HRA can overcome the problems of cold start and data sparsity, and achieve good recommendation accuracy and scalability for employment recommendation.

  8. Recommender systems in knowledge-mining

    Science.gov (United States)

    Volna, Eva

    2017-07-01

    The subject of the paper is to analyse the possibilities of application of recommender systems in the field of data mining. The work focuses on three basic types of recommender systems (collaborative, content-based and hybrid). The goal of the article is to evaluate which of these three concepts of recommender systems provides forecast with the lowest error rate in the domain of recommending movies. This target is fulfilled by the practical part of the work - at first, the own recommender system was designed and created, capable of obtaining movies recommendation from the database based on the user's preferences. Next, we verified experimentally which recommender system produces more accurate results.

  9. Research on Long Tail Recommendation Algorithm

    Science.gov (United States)

    Hu, Xuezhi; Zhang, Chuang; Wu, Ming; Zeng, Yang

    2017-10-01

    Most recommendation systems in the major electronic commerce platforms are influenced by the long tail effect more or less. There are sufficient researches of how to assess recommendation effect while no criteria to evaluate long tail recommendation rate. In this study, we first discussed the existing problems of recommending long tail products through specific experiments. Then we proposed a long tail evaluation criteria and compared the performance in long tail recommendation between different models.

  10. Recommended system of application and development

    Science.gov (United States)

    Wang, Wei

    2018-04-01

    A recommender system is a project that helps users identify their wishes and needs. The recommender system has been successfully applied to many e-commerce environments, such as news, film, music, books and other areas of recommendation. This paper mainly discusses the application of recommendation technology in software engineering, data and knowledge engineering, configurable projects and persuasion technology, and summarizes the development trend of recommendation technology in the future.

  11. Distribution of cesium-137 in tree crop products collected from residence islands impacted by the U.S. nuclear test program in the northern Marshall Islands

    International Nuclear Information System (INIS)

    Peters, S.K.G.; Kehl, S.R.; Martinelli, R.E.; Tamblin, M.W.; Hamilton, T.F.

    2013-01-01

    The Marshall Islands Program at the Lawrence Livermore National Laboratory has completed a series of radiological surveys at Bikini, Rongelap, Utroek, and Enewetak Atolls in the Marshall Islands designed to take a representative sample of food supplies with emphasis on determining 137 Cs activity concentrations in common food plants. Coconuts (Cocos nucifera L.) are the most common and abundant food plant, and provided a common sample type to characterize the level and variability of activity concentrations of 137 Cs in plant foods collected from different islands and atolls. Other dominant food types included Pandanus (Pandanus spp.) and breadfruit (Actocarpus spp.). In general, the activity concentration of 137 Cs in food plants was found to decrease significantly between the main residence islands on Bikini, Rongelap, Utrōk, and Enewetak Atolls. The mean activity concentration of 137 Cs measured in drinking coconut meat and juice was 0.72 (95 % CI 0.68-0.77) and 0.34 (95 % CI 0.30-0.38) Bq g -1 , respectively, on Bikini Island; 0.019 (95 % CI 0.017-0.021) and 0.027 (95 % CI 0.023-0.031) Bq g -1 , respectively, on Rongelap Island; 0.010 (95 % CI 0.007-0.013) and 0.007 (95 % CI 0.004-0.009) Bq g -1 , respectively, on Utroek Island; and 0.002 (95 % CI 0.0013-0.0024) and 0.002 (95 % CI 0.001-0.0025) Bq g -1 , respectively, on Enewetak Island. High levels of variability are reported across all islands. These results will be used to improve the accuracy and reliability of predictive dose assessments, help characterize levels of uncertainty and variability in activity concentrations of fallout radionuclides in plant foods, and allow atoll communities to make informed decisions about resettlement and possible options for cleanup and rehabilitation of islands and atolls. (author)

  12. Ransomware - Threats Vulnerabilities And Recommendations

    Directory of Open Access Journals (Sweden)

    Nadeem Shah

    2017-06-01

    Full Text Available Attack methodologies transform with the transforming dynamics of technology. Consequently it becomes imperative that individuals and organization implement the highest levels of security within their devices and infrastructure for optimal protection against these rapidly evolving attacks. Ransomware is one such attack that never fails to surprise in terms of its ability to identify vulnerabilities and loopholes in technology. This paper discusses the categories of ransomware its common attack vectors and provides a threat landscape with the aim to highlight the true potential and destructive nature of such malware based attacks. In this paper we also present the most current ransomware attack that is still a potential threat and also provide recommendations and strategies for prevention and protection against these attacks. A novel solution is also discussed that could be further worked upon in the future by other researchers and vendors of security devices.

  13. Summary, analysis, and policy recommendations

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Four policy recommendations are presented that would provide the foundations for a long-term transportation policy for the US while gradually reducing the threats from petroleum-powered vehicles to the climate and air quality. They include: improvements in new-vehicle fuel efficiency; increased transportation system efficiency; development of non-fossil energy sources for transportation; and reduction of other greenhouse gas emissions. In the future, manufacturers will be under pressure to develop petroleum-powered vehicles that are cleaner, safer, and more fuel efficient; at the same time, they will need to develop new kinds of vehicles that will emit no pollutants. This pressure will come not from market forces but from public policy and will require large amounts of capital

  14. A heterogeneous graph-based recommendation simulator

    Energy Technology Data Exchange (ETDEWEB)

    Yeonchan, Ahn [Seoul National University; Sungchan, Park [Seoul National University; Lee, Matt Sangkeun [ORNL; Sang-goo, Lee [Seoul National University

    2013-01-01

    Heterogeneous graph-based recommendation frameworks have flexibility in that they can incorporate various recommendation algorithms and various kinds of information to produce better results. In this demonstration, we present a heterogeneous graph-based recommendation simulator which enables participants to experience the flexibility of a heterogeneous graph-based recommendation method. With our system, participants can simulate various recommendation semantics by expressing the semantics via meaningful paths like User Movie User Movie. The simulator then returns the recommendation results on the fly based on the user-customized semantics using a fast Monte Carlo algorithm.

  15. A Group Recommender System for Tourist Activities

    Science.gov (United States)

    Garcia, Inma; Sebastia, Laura; Onaindia, Eva; Guzman, Cesar

    This paper introduces a method for giving recommendations of tourist activities to a group of users. This method makes recommendations based on the group tastes, their demographic classification and the places visited by the users in former trips. The group recommendation is computed from individual personal recommendations through the use of techniques such as aggregation, intersection or incremental intersection. This method is implemented as an extension of the e-Tourism tool, which is a user-adapted tourism and leisure application, whose main component is the Generalist Recommender System Kernel (GRSK), a domain-independent taxonomy-driven search engine that manages the group recommendation.

  16. Measurement of background gamma radiation in the northern Marshall Islands.

    Science.gov (United States)

    Bordner, Autumn S; Crosswell, Danielle A; Katz, Ainsley O; Shah, Jill T; Zhang, Catherine R; Nikolic-Hughes, Ivana; Hughes, Emlyn W; Ruderman, Malvin A

    2016-06-21

    We report measurements of background gamma radiation levels on six islands in the northern Marshall Islands (Enewetak, Medren, and Runit onEnewetak Atoll; Bikini and Nam on Bikini Atoll; and Rongelap on Rongelap Atoll). Measurable excess radiation could be expected from the decay of (137)Cs produced by the US nuclear testing program there from 1946 to 1958. These recordings are of relevance to safety of human habitation and resettlement. We find low levels of gamma radiation for the settled island of Enewetak [mean = 7.6 millirem/year (mrem/y) = 0.076 millisievert/year (mSv/y)], larger levels of gamma radiation for the island of Rongelap (mean = 19.8 mrem/y = 0.198 mSv/y), and relatively high gamma radiation on the island of Bikini (mean = 184 mrem/y = 1.84 mSv/y). Distributions of gamma radiation levels are provided, and hot spots are discussed. We provide interpolated maps for four islands (Enewetak, Medren, Bikini, and Rongelap), and make comparisons to control measurements performed on the island of Majuro in the southern Marshall Islands, measurements made in Central Park in New York City, and the standard agreed upon by the United States and the Republic of the Marshall Islands (RMI) governments (100 mrem/y = 1 mSv/y). External gamma radiation levels on Bikini Island significantly exceed this standard (P = <0.01), and external gamma radiation levels on the other islands are below the standard. To determine conclusively whether these islands are safe for habitation, radiation exposure through additional pathways such as food ingestion must be considered.

  17. Concentration of Beryllium (Be) and Depleted Uranium (DU) in Marine Fauna and Sediment Samples from Illeginni and Boggerik Islands at Kwajalein Atoll

    International Nuclear Information System (INIS)

    Robison, W L; Hamilton, T F; Martinelli, R E; Kehl, S R; Lindman, T R

    2005-01-01

    Lawrence Livermore National Laboratory (LLNL) personnel have supported US Air Force (USAF) ballistic missile flight tests for about 15 years for Peacekeeper and Minuteman missiles launched at Vandenberg Air Force Base (VAFB). Associated re-entry vehicles (RV's) re-enter at Regan Test Site (RTS) at the US Army base at Kwajalein Atoll (USAKA) where LLNL has supported scoring, recovery operations for RV materials, and environmental assessments. As part of ongoing USAF ballistic missile flight test programs, LLNL is participating in an updated EA being written for flights originating at VFAB. Marine fauna and sediments (beach-sand samples) were collected by US Fish and Wildlife Service (USFWS), National Marine Fisheries Service (NMFS), and LLNL at Illeginni Island and Boggerik Island (serving as a control site) at Kwajalein Atoll. Data on the concentration of DU (hereafter, U) and Be in collected samples was requested by USFWS and NMFS to determine whether or not U and Be in RV's entering the Illeginni area are increasing U and Be concentrations in marine fauna and sediments. LLNL agreed to do the analyses for U and Be in support of the EA process and provide a report of the results. There is no statistically significant difference in the concentration of U and Be in six species of marine fauna from Illeginni and Boggerik Islands (p - 0.14 for U and p = 0.34 for Be). Thus, there is no evidence that there has been any increase in U and Be concentrations in marine fauna as a result of the missile flight test program. Concentration of U in beach sand at Illeginni is the same as soil and beach sand in the rest of the Marshall Islands and again reflects an insignificant impact from the flight test program. Beach sand from Illeginni has a mean concentration of Be higher than that from the control site, Boggeik Island. Seven of 21 samples from Ileginni had detectable Be. Four samples had a concentration of Be ranging from 4 to 7 ng g -1 (4 to 7 parts per billion (ppb)), one

  18. Multi-decadal shoreline changes on Takú Atoll, Papua New Guinea: Observational evidence of early reef island recovery after the impact of storm waves

    Science.gov (United States)

    Mann, Thomas; Westphal, Hildegard

    2016-03-01

    Hurricanes, tropical cyclones and other high-magnitude events are important steering mechanisms in the geomorphic development of coral reef islands. Sandy reef islands located outside the storm belts are strongly sensitive to the impact of occasional high-magnitude events and show abrupt, commonly erosive geomorphic change in response to such events. Based on the interpretation of remote sensing data, it is well known that the process of landform recovery might take several decades or even longer. However, despite the increasing amount of scientific attention towards short- and long-term island dynamics, the lack of data and models often prevent a robust analysis of the timing and nature of recovery initiation. Here we show how natural island recovery starts immediately after the impact of a high-magnitude event. We analyze multi-temporal shoreline changes on Takú Atoll, Papua New Guinea and combine our findings with a unique set of published field observations (Smithers and Hoeke, 2014). Trends of shoreline change since 1943 and changes in planform island area indicate a long-term accretionary mode for most islands. Apparent shoreline instability is detected for the last decade of analysis, however this can be explained by the impact of storm waves in December 2008 that (temporarily?) masked the long-term trend. The transition from negative to positive rates of change in the aftermath of this storm event is indicative of inherent negative feedback processes that counteract short-term changes in energy input and represent the initiation of island recovery. Collectively, our results support the concept of dynamic rather than static reef islands and clearly demonstrate how short-term processes can influence interpretations of medium-term change.

  19. Carbon budget of coral reef systems: an overview of observations in fringing reefs, barrier reefs and atolls in the Indo-Pacific regions

    International Nuclear Information System (INIS)

    Suzuki, Atsushi; Kawahata, Hodaka

    2003-01-01

    The seawater CO 2 system and carbon budget were examined in coral reefs of wide variety with respect to topographic types and oceanographic settings in the Indo-Pacific oceans. A system-level net organic-to-inorganic carbon production ratio (ROI) is a master parameter for controlling the carbon cycle in coral reef systems, including their sink/source behavior for atmospheric CO 2 . A reef system with ROI less than approximately 0.6 has a potential for releasing CO 2 . The production ratio, however, is not easy to estimate on a particular reef. Instead, observations planned to detect the offshore-lagoon difference in partial pressure of CO 2 (pCO 2 ) and a graphic approach based on a total alkalinity-dissolved inorganic carbon diagram can reveal system-level performance of the carbon cycle in coral reefs. Surface pCO 2 values in the lagoons of atolls and barrier reefs were consistently higher than those in their offshore waters, showing differences between 6 and 46 atm, together with a depletion in total alkalinity up to 100 mol/kg, indicating predominant carbonate production relative to net organic carbon production. Reef topography, especially residence time of lagoon water, has a secondary effect on the magnitude of the offshore-lagoon pCO 2 difference. Terrestrial influence was recognized in coastal reefs, including the GBR lagoon and a fringing reef of the Ryukyu Islands. High carbon input appears to enhance CO 2 efflux to the atmosphere because of their high dissolved C:P ratios. Coral reefs, in general, act as an alkalinity sink and a potentially CO 2 -releasing site due to carbonate precipitation and land-derived carbon

  20. Carbon budget of coral reef systems: an overview of observations in fringing reefs, barrier reefs and atolls in the Indo-Pacific regions

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Atsushi; Kawahata, Hodaka [National Inst. of Advanced Industrial Science and Technology, Ibaraki (Japan). Inst. for Marine Resources and Environment

    2003-04-01

    The seawater CO{sub 2} system and carbon budget were examined in coral reefs of wide variety with respect to topographic types and oceanographic settings in the Indo-Pacific oceans. A system-level net organic-to-inorganic carbon production ratio (ROI) is a master parameter for controlling the carbon cycle in coral reef systems, including their sink/source behavior for atmospheric CO{sub 2}. A reef system with ROI less than approximately 0.6 has a potential for releasing CO{sub 2}. The production ratio, however, is not easy to estimate on a particular reef. Instead, observations planned to detect the offshore-lagoon difference in partial pressure of CO{sub 2} (pCO{sub 2}) and a graphic approach based on a total alkalinity-dissolved inorganic carbon diagram can reveal system-level performance of the carbon cycle in coral reefs. Surface pCO{sub 2} values in the lagoons of atolls and barrier reefs were consistently higher than those in their offshore waters, showing differences between 6 and 46 atm, together with a depletion in total alkalinity up to 100 mol/kg, indicating predominant carbonate production relative to net organic carbon production. Reef topography, especially residence time of lagoon water, has a secondary effect on the magnitude of the offshore-lagoon pCO{sub 2} difference. Terrestrial influence was recognized in coastal reefs, including the GBR lagoon and a fringing reef of the Ryukyu Islands. High carbon input appears to enhance CO{sub 2} efflux to the atmosphere because of their high dissolved C:P ratios. Coral reefs, in general, act as an alkalinity sink and a potentially CO{sub 2}-releasing site due to carbonate precipitation and land-derived carbon.

  1. An assessment of non-communicable diseases, diabetes, and related risk factors in the Republic of the Marshall Islands, Majuro Atoll: a systems perspective.

    Science.gov (United States)

    Ichiho, Henry M; deBrum, Ione; Kedi, Shra; Langidrik, Justina; Aitaoto, Nia

    2013-05-01

    Non-communicable diseases (NCD) have been identified as a health emergency in the US-associated Pacific Islands (USAPI).1 This assessment, funded by the National Institutes of Health, was conducted in the Republic of the Marshall Islands, Majuro Atoll and describes the burdens due to selected NCD (diabetes, heart disease, hypertension, stroke, chronic kidney disease); and assesses the system of service capacity and current activities for service delivery, data collection and reporting as well as identifying the issues that need to be addressed. Findings reveal that the risk factors of poor diet, lack of physical activity, and risky lifestyle behaviors are associated with overweight and obesity and subsequent NCD that are significant factors in the morbidity and mortality of the population. The leading causes of death include sepsis, cancer, diabetes-related deaths, pneumonia, and hypertension. Population-based survey for the RMI show that 62.5% of the adults are overweight or obese and the prevalence of diabetes stands at 19.6%. Other findings show significant gaps in the system of administrative, clinical, data, and support services to address these NCD. There is no policy and procedure manual for the hospital or public health diabetes clinics and there is little communication, coordination, or collaboration between the medical and public health staff. There is no functional data system that allows for the identification, registry, or tracking of patients with diabetes or other NCDs. Based on these findings, priority issues and problems to be addressed for the administrative, clinical, and data systems were identified.

  2. Time-resolved record of 236U and 239,240Pu isotopes from a coral growing during the nuclear testing program at Enewetak Atoll (Marshall Islands).

    Science.gov (United States)

    Froehlich, M B; Chan, W Y; Tims, S G; Fallon, S J; Fifield, L K

    2016-12-01

    A comprehensive series of nuclear tests were carried out by the United States at Enewetak Atoll in the Marshall Islands, especially between 1952 and 1958. A Porites Lutea coral that was growing in the Enewetak lagoon within a few km of all of the high-yield tests contains a continuous record of isotopes, which are of interest (e.g. 14 C, 236 U, 239,240 Pu) through the testing period. Prior to the present work, 14 C measurements at ∼2-month resolution had shown pronounced peaks in the Δ 14 C data that coincided with the times at which tests were conducted. Here we report measurements of 236 U and 239,240 Pu on the same coral using accelerator mass spectrometry, and again find prominent peaks in the concentrations of these isotopes that closely follow those in 14 C. Consistent with the 14 C data, the magnitudes of these peaks do not, however, correlate well with the explosive yields of the corresponding tests, indicating that smaller tests probably contributed disproportionately to the debris that fell in the lagoon. Additional information about the different tests can also be obtained from the 236 U/ 239 Pu and 240 Pu/ 239 Pu ratios, which are found to vary dramatically over the testing period. In particular, the first thermonuclear test, Ivy-Mike, has characteristic 236 U/ 239 Pu and 240 Pu/ 239 Pu signatures which are diagnostic of the first arrival of nuclear test material in various archives. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Recommender Systems in Technology Enhanced Learning

    NARCIS (Netherlands)

    Manouselis, Nikos; Drachsler, Hendrik; Vuorikari, Riina; Hummel, Hans; Koper, Rob

    2010-01-01

    Manouselis, N., Drachsler, H., Vuorikari, R., Hummel, H. G. K., & Koper, R. (2011). Recommender Systems in Technology Enhanced Learning. In P. B. Kantor, F. Ricci, L. Rokach, & B. Shapira (Eds.), Recommender Systems Handbook (pp. 387-415). Berlin: Springer.

  4. Preventive Care Recommendations for Adults with MS

    Science.gov (United States)

    ... risk factors including prolonged use of steroids or anticonvulsants, a family history of osteoporosis, and a sedentary ... care provider. Yearly. Monthly. The American Academy of Pediatrics recommends starting at age eighteen. Preventive Care Recommendations | ...

  5. Great Explanations: Opinionated Explanations for Recommendation

    OpenAIRE

    Muhammad, Khalil; Lawlor, Aonghus; Rafter, Rachael; Smyth, Barry

    2015-01-01

    Explaining recommendations helps users to make better, more satisfying decisions. We describe a novel approach to explanation for recommender systems, one that drives the recommendation process, while at the same time providing the user with useful insights into the reason why items have been chosen and the trade-os they may need to consider when making their choice. We describe this approach in the context ofa case-based recommender system that harnesses opinions mined from user-generated re...

  6. Recommendation System Based on Fuzzy Cognitive Map

    OpenAIRE

    Wei Liu; Linzhi Gao

    2014-01-01

    With the increase of data volume and visitor volume, the website faces great challenge in the environment of network. How to know the users’ requirements rapidly and effectively and recommend the required information to the user becomes the research direction of all websites. The researchers of recommendation system propose a series of recommendation system models and algorithms for the user. The common challenge faced by these algorithms is how to judge the user intention and recommend...

  7. Recommendations, requirements, and radioactive particles

    International Nuclear Information System (INIS)

    Bell, J.M.

    1991-01-01

    Hot particles consisting of activated metal debris and fuel fragments have received increased attention in the last five years. This increased attention resulted from the increased use of more sensitive whole body friskers at nuclear power plants, the relatively high local skin doses associated with the particles, and skin dose limits that were established before hot particles, and skin dose limits that were established before hot particles became a problem and before radiobiological effects data for the particles became available. The skin dose distribution and biological effects associated with hot particles differ from those associated with more uniform skin contamination and differences exist in the scientific community as to which effects should be protected against by a limit on exposures from particles. The NRC staff recognized the need for provisions in the Federal regulations specific to hot particle exposures and requested guidance from the National Council on Radiation Protection and Measurements (NCRP). NCRP Report No. 106 was provided to the NRC early in 1990. The International Commission on Radiological Protection (ICRP) is also developing recommendations for limits on exposures from hot particles. The NRC is supporting research on hot particle effects and will likely develop a rule for hot particle exposures

  8. Permian Basin location recommendation report

    International Nuclear Information System (INIS)

    1983-09-01

    Candidate study areas are screened from the Palo Duro and Dalhart Basin areas using data obtained from studies to date and criteria and specifications that consider: rock geometry; rock characteristics; human intrusion potential; surface characteristics; and environmental and socioeconomic conditions. Two preferred locations are recommended from among these areas for additional characterization to identify potential National Waste Terminal Storage (NWTS) salt repository sites. One location, in northeastern Deaf Smith County and southeastern Oldham County, is underlain by two salt units that meet the adopted screening specifications. The other location, in northcentral Swisher County, is underlain by one salt unit that meets the adopted screening specifications. Both locations have several favorable features, relative to surrounding areas, and no obviously undesirable characteristics. Both lie wholly on the Southern High Plains surface, are in relatively sparsely populated areas, contain no unique land use conflicts, and comprise large enough geographic areas to provide flexibility in site selection. Data gathered to date indicate that these locations contain salt units sufficient in thickness and in depth for the safe construction and operation of the underground facilities under consideration. 93 references, 34 figures, 6 tables

  9. Epilepsy surgery: Recommendations for India

    Directory of Open Access Journals (Sweden)

    Chandra P

    2010-01-01

    Full Text Available The following article recommends guidelines for epilepsy surgery for India. This article reviews the indications, the various surgical options available and the outcome of surgery for drug resistant epilepsy based on current evidence. Epilepsy surgery is a well-established option for patients who have been diagnosed to have drug resistant epilepsy (DRE (on at least two appropriate, adequate anti-epileptic drugs (AEDs (either in monotherapy or in combination with continuing seizures, where the presurgical work-up has shown concordance of structural imaging (magnetic resonance imaging and electrical mapping data (electroencephalography (EEG, video EEG. There may be a requirement of functional imaging techniques in a certain number of DRE like positron emission tomography (PET, single photon emission tomography, (SPECT. Invasive monitoring should be restricted to a few when all noninvasive investigations are inconclusive, there is a dual pathology or there is a discordance of noninvasive data. The types of surgery could be curative (resective surgeries: amygdalo hippocampectomy, lesionectomy and multilobar resections; functional surgeries: hemispherotomy and palliative (multiple subpial transaction, corpus callosotomy, vagal nerve stimulation. Epilepsy surgery in indicated cases has a success range from 50 to 86% in achieving seizure freedom as compared with < 5% success rate with AEDs only in persons with DRE. Centers performing surgery should be categorized into Level I and Level II.

  10. Epilepsy and recommendations for breastfeeding.

    Science.gov (United States)

    Veiby, Gyri; Bjørk, Marte; Engelsen, Bernt A; Gilhus, Nils Erik

    2015-05-01

    The objective of this paper is to provide a synopsis of benefits and potential harmful effects of exposure to antiepileptic drugs (AEDs) via breastmilk, and present recommendations for breastfeeding in women with epilepsy. The article is based on a discretionary selection of English language articles retrieved by a literature search in the PubMed database, the LactMed database, and the authors' clinical experience. Breastfeeding is associated with benefits for the infant, including nutrition, protection against infectious and immunological disease, and promotion of development and psychological attachment. Exposure to AEDs via breastmilk could potentially produce side effects or negatively affect development. Most studies on AED transfer through breastmilk report infant serum levels well below the limit of an expected pharmacological effect. Some drugs have the potential to reach significant serum levels in breastfed infants, such as barbiturates, benzodiazepines, lamotrigine, and ethosuximide. Thus, breastfed infants should be monitored for side effects. Still, adverse symptoms are rarely reported in breastfed infants of mothers taking AEDs, and prospective studies have failed to demonstrate any negative developmental effects in children that have been exposed to AEDs via breastmilk. The nursing infant's degree of drug exposure can be minimized by breastfeeding when drug concentrations in the milk are low, reducing maternal AED dosage to prepregnancy levels, and administering mixed nutrition. Most AEDs are considered safe or moderately safe during breastfeeding. Mothers with epilepsy should be encouraged to breastfeed, provided careful monitoring of the infant. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  11. Decision-Guided Recommenders with Composite Alternatives

    Science.gov (United States)

    Alodhaibi, Khalid

    2011-01-01

    Recommender systems aim to support users in their decision-making process while interacting with large information spaces and recommend items of interest to users based on preferences they have expressed, either explicitly or implicitly. Recommender systems are increasingly used with product and service selection over the Internet. Although…

  12. Panorama of Recommender Systems to Support Learning

    NARCIS (Netherlands)

    Drachsler, Hendrik; Verbert, Katrien; Santos, Olga C.; Manouselis, Nikos

    2015-01-01

    This chapter presents an analysis of recommender systems in TechnologyEnhanced Learning along their 15 years existence (2000-2014). All recommender systems considered for the review aim to support educational stakeholders by personalising the learning process. In this meta-review 82 recommender

  13. Explaining the user experience of recommender systems

    NARCIS (Netherlands)

    Knijnenburg, B.P.; Willemsen, M.C.; Gantner, Z.; Soncu, H.; Newell, C.

    2012-01-01

    Research on recommender systems typically focuses on the accuracy of prediction algorithms. Because accuracy only partially constitutes the user experience of a recommender system, this paper proposes a framework that takes a user-centric approach to recommender system evaluation. The framework

  14. Paired analyst recommendations and internet IPOs

    NARCIS (Netherlands)

    van der Goot, T.; van Giersbergen, N.

    2008-01-01

    The paper investigates analyst recommendations for internet firms that went public during 1997-2000. Our contribution to the literature is that we match recommendations for the same firm issued by different investment banks that have published the recommendations in an interval around the same date.

  15. Cryptographically-Enhanced Privacy for Recommender Systems

    NARCIS (Netherlands)

    Jeckmans, Arjan

    2014-01-01

    Automated recommender systems are used to help people find interesting content or persons in the vast amount of information available via the internet. There are different types of recommender systems, for example collaborative filtering systems and content-based recommender systems. However, all

  16. Toward Privacy-Preserving Personalized Recommendation Services

    Directory of Open Access Journals (Sweden)

    Cong Wang

    2018-02-01

    Full Text Available Recommendation systems are crucially important for the delivery of personalized services to users. With personalized recommendation services, users can enjoy a variety of targeted recommendations such as movies, books, ads, restaurants, and more. In addition, personalized recommendation services have become extremely effective revenue drivers for online business. Despite the great benefits, deploying personalized recommendation services typically requires the collection of users’ personal data for processing and analytics, which undesirably makes users susceptible to serious privacy violation issues. Therefore, it is of paramount importance to develop practical privacy-preserving techniques to maintain the intelligence of personalized recommendation services while respecting user privacy. In this paper, we provide a comprehensive survey of the literature related to personalized recommendation services with privacy protection. We present the general architecture of personalized recommendation systems, the privacy issues therein, and existing works that focus on privacy-preserving personalized recommendation services. We classify the existing works according to their underlying techniques for personalized recommendation and privacy protection, and thoroughly discuss and compare their merits and demerits, especially in terms of privacy and recommendation accuracy. We also identity some future research directions. Keywords: Privacy protection, Personalized recommendation services, Targeted delivery, Collaborative filtering, Machine learning

  17. Preference-Based Recommendations for OLAP Analysis

    Science.gov (United States)

    Jerbi, Houssem; Ravat, Franck; Teste, Olivier; Zurfluh, Gilles

    This paper presents a framework for integrating OLAP and recommendations. We focus on the anticipatory recommendation process that assists the user during his OLAP analysis by proposing to him the forthcoming analysis step. We present a context-aware preference model that matches decision-makers intuition, and we discuss a preference-based approach for generating personalized recommendations.

  18. An Agent Framework of Tourism Recommender System

    Directory of Open Access Journals (Sweden)

    Jia Zhi Yang

    2016-01-01

    Full Text Available This paper proposes the development of an Agent framework for tourism recommender system. The recommender system can be featured as an online web application which is capable of generating a personalized list of preference attractions for tourists. Traditional technologies of classical recommender system application domains, such as collaborative filtering, content-based filtering and content-based filtering are effectively adopted in the framework. In the framework they are constructed as Agents that can generate recommendations respectively. Recommender Agent can generate recommender information by integrating the recommendations of Content-based Agent, collaborative filtering-based Agent and constraint-based Agent. In order to make the performance more effective, linear combination method of data fusion is applied. User interface is provided by the tourist Agent in form of webpages and mobile app.

  19. The Definition of Novelty in Recommendation System

    Directory of Open Access Journals (Sweden)

    Liang Zhang

    2013-01-01

    Full Text Available With the development of information technology and application of the Internet, People gradually entered the time of information overload from information scarcity. User satisfaction with recommender systems is related not only to how accurately the system recommends but also to how much it supports the user’s decision making. Novelty is one of the important metrics of customer satisfaction. There is an increasing realization in the Recommender Systems (RS field that novelty is fundamental qualities of recommendation effectiveness and added-value. This paper combed research results about definition and algorithm of novel recommendation, and starting from the meaning of "novel", defined novelty of item in recommendation system. Experiment proved using the definition of novelty to recommend can effectively recognize the item that the user is familiar with and ensure certain accuracy.

  20. Defining and Supporting Narrative-driven Recommendation

    DEFF Research Database (Denmark)

    Bogers, Toine; Koolen, Marijn

    2017-01-01

    Research into recommendation algorithms has made great strides in recent years. However, these algorithms are typically applied in relatively straightforward scenarios: given information about a user's past preferences, what will they like in the future? Recommendation is often more complex......: evaluating recommended items never takes place in a vacuum, and it is often a single step in the user's more complex background task. In this paper, we define a specific type of recommendation scenario called narrative-driven recommendation, where the recommendation process is driven by both a log...... of the user's past transactions as well as a narrative description of their current interest(s). Through an analysis of a set of real-world recommendation narratives from the LibraryThing forums, we demonstrate the uniqueness and richness of this scenario and highlight common patterns and properties...

  1. Hybrid recommendation methods in complex networks.

    Science.gov (United States)

    Fiasconaro, A; Tumminello, M; Nicosia, V; Latora, V; Mantegna, R N

    2015-07-01

    We propose two recommendation methods, based on the appropriate normalization of already existing similarity measures, and on the convex combination of the recommendation scores derived from similarity between users and between objects. We validate the proposed measures on three data sets, and we compare the performance of our methods to other recommendation systems recently proposed in the literature. We show that the proposed similarity measures allow us to attain an improvement of performances of up to 20% with respect to existing nonparametric methods, and that the accuracy of a recommendation can vary widely from one specific bipartite network to another, which suggests that a careful choice of the most suitable method is highly relevant for an effective recommendation on a given system. Finally, we study how an increasing presence of random links in the network affects the recommendation scores, finding that one of the two recommendation algorithms introduced here can systematically outperform the others in noisy data sets.

  2. A general framework for intelligent recommender systems

    Directory of Open Access Journals (Sweden)

    Jose Aguilar

    2017-07-01

    Full Text Available In this paper, we propose a general framework for an intelligent recommender system that extends the concept of a knowledge-based recommender system. The intelligent recommender system exploits knowledge, learns, discovers new information, infers preferences and criticisms, among other things. For that, the framework of an intelligent recommender system is defined by the following components: knowledge representation paradigm, learning methods, and reasoning mechanisms. Additionally, it has five knowledge models about the different aspects that we can consider during a recommendation: users, items, domain, context and criticisms. The mix of the components exploits the knowledge, updates it and infers, among other things. In this work, we implement one intelligent recommender system based on this framework, using Fuzzy Cognitive Maps (FCMs. Next, we test the performance of the intelligent recommender system with specialized criteria linked to the utilization of the knowledge in order to test the versatility and performance of the framework.

  3. Whole-body counting in the Marshall Islands

    International Nuclear Information System (INIS)

    Sun, L.C.; Clinton, J.; Kaplan, E.; Meinhold, C.B.

    1991-01-01

    In 1978 the Marshall Islands Radiological Safety Program was organized to perform radiation measurements and assess radiation doses for the people of the Bikini, Enewetak, Rongelap and Utirik Atolls. One of the major field components of this program is whole- body counting (WBC). WBC is used to monitor the quantity of gamma- emitting radionuclides present in individuals. A primary objective of the program was to establish 137 Cesium body contents among the Enewetak, Rongelap and Utirik populations. 137 Cs was the only gamma-emitting fission radionuclide detected in the 1,967 persons monitored. 137 Cs body burdens tended to increase with age for both sexes, and were higher in males. The average 137 Cs dose Annual Effective Dose for the three populations was as follows: For Enewetak, the dose was 22±4 μSv. For Utirik, the dose was 33± 3 μSv. Since 1985 the Rongelap people have been self-exiled to Mejatto. Biological elimination should have reduced their dose to virtually zero, and the measured dose was 2±2 μSv. If they had remained on Rongelap Island, the calculated dose would have been 99 μSv, which is about one-third of the background dose. 7 refs., 1 tab

  4. Missed hormonal contraceptives: new recommendations.

    Science.gov (United States)

    Guilbert, Edith; Black, Amanda; Dunn, Sheila; Senikas, Vyta

    2008-11-01

    To provide evidence-based guidance for women and their health care providers on the management of missed or delayed hormonal contraceptive doses in order to prevent unintended pregnancy. Medline, PubMed, and the Cochrane Database were searched for articles published in English, from 1974 to 2007, about hormonal contraceptive methods that are available in Canada and that may be missed or delayed. Relevant publications and position papers from appropriate reproductive health and family planning organizations were also reviewed. The quality of evidence is rated using the criteria developed by the Canadian Task Force on Preventive Health Care. This committee opinion will help health care providers offer clear information to women who have not been adherent in using hormonal contraception with the purpose of preventing unintended pregnancy. The Society of Obstetricians and Gynaecologists of Canada. SUMMARY STATEMENTS: 1. Instructions for what women should do when they miss hormonal contraception have been complex and women do not understand them correctly. (I) 2. The highest risk of ovulation occurs when the hormone-free interval is prolonged for more than seven days, either by delaying the start of combined hormonal contraceptives or by missing active hormone doses during the first or third weeks of combined oral contraceptives. (II) Ovulation rarely occurs after seven consecutive days of combined oral contraceptive use. (II) RECOMMENDATIONS: 1. Health care providers should give clear, simple instructions, both written and oral, on missed hormonal contraceptive pills as part of contraceptive counselling. (III-A) 2. Health care providers should provide women with telephone/electronic resources for reference in the event of missed or delayed hormonal contraceptives. (III-A) 3. In order to avoid an increased risk of unintended pregnancy, the hormone-free interval should not exceed seven days in combined hormonal contraceptive users. (II-A) 4. Back-up contraception should

  5. Recommender Systems for the Social Web

    CERN Document Server

    Pazos Arias, José J; Díaz Redondo, Rebeca P

    2012-01-01

    The recommendation of products, content and services cannot be considered newly born, although its widespread application is still in full swing. While its growing success in numerous sectors, the progress of the  Social Web has revolutionized the architecture of participation and relationship in the Web, making it necessary to restate recommendation and reconciling it with Collaborative Tagging, as the popularization of authoring in the Web, and  Social Networking, as the translation of personal relationships to the Web. Precisely, the convergence of recommendation with the above Social Web pillars is what motivates this book, which has collected contributions from well-known experts in the academy and the industry to provide a broader view of the problems that Social Recommenders might face with.  If recommender systems have proven their key role in facilitating the user access to resources on the Web, when sharing resources has become social, it is natural for recommendation strategies in the Social Web...

  6. RECOMMENDER SYSTEMS IN E-COMMERCE APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Gyöngyvér KOVÁCS

    2016-12-01

    Full Text Available One of the major problem with online shopping is finingd the right product, because finding the right product presumes that we know its name, but in most cases it is not so. For this reason the users need help in the process of online searching/shopping. Recommender systems have became a popular technique and strategy for helping users to select desirable products or services. In the past few years the recommender systems have changed from novelties used by a few big e-commerce sites, to serious business tools that are re-shaping the world of e-commerce. In this paper, we provide a brief overview of the classification of recommendation systems based on technology used to create recommendations, and inputs they need from the customers. Furthermore we analyze a few algorithms used by recommender systems and we will also present some marketing recommender systems and their comparative analysis.

  7. Network-based recommendation algorithms: A review

    Science.gov (United States)

    Yu, Fei; Zeng, An; Gillard, Sébastien; Medo, Matúš

    2016-06-01

    Recommender systems are a vital tool that helps us to overcome the information overload problem. They are being used by most e-commerce web sites and attract the interest of a broad scientific community. A recommender system uses data on users' past preferences to choose new items that might be appreciated by a given individual user. While many approaches to recommendation exist, the approach based on a network representation of the input data has gained considerable attention in the past. We review here a broad range of network-based recommendation algorithms and for the first time compare their performance on three distinct real datasets. We present recommendation topics that go beyond the mere question of which algorithm to use-such as the possible influence of recommendation on the evolution of systems that use it-and finally discuss open research directions and challenges.

  8. Fusing Recommendations for Social Bookmarking Websites

    DEFF Research Database (Denmark)

    Bogers, Toine; van den Bosch, Antal

    2011-01-01

    Social bookmarking websites are rapidly growing in popularity. Recommender systems, a promising remedy to the information overload accompanying the explosive growth in content, are designed to identify which unseen content might be of interest to a particular user, based on his or her past...... that use tag overlap and metadata provide better results for social bookmarking data sets than the transaction patterns that are used traditionally in recommender systems research. In addition, we investigate how to fuse different recommendation approaches to further improve recommendation accuracy. We...... preferences. Most previous work in recommendation for social bookmarking suffers from a lack of comparisons between the different available approaches. In this article, we address this issue by comparing and evaluating eight recommendation approaches on four data sets from two domains. We find that approaches...

  9. ISFG: Recommendations on biostatistics in paternity testing

    DEFF Research Database (Denmark)

    Gjertson, David W; Brenner, Charles H; Baur, Max P

    2007-01-01

    The Paternity Testing Commission (PTC) of the International Society for Forensic Genetics has taken up the task of establishing the biostatistical recommendations in accordance with the ISO 17025 standards and a previous set of ISFG recommendations specific to the genetic investigations...... in paternity cases. In the initial set, the PTC recommended that biostatistical evaluations of paternity are based on a likelihood ratio principle - yielding the paternity index, PI. Here, we have made five supplementary biostatistical recommendations. The first recommendation clarifies and defines basic...... concepts of genetic hypotheses and calculation concerns needed to produce valid PIs. The second and third recommendations address issues associated with population genetics (allele probabilities, Y-chromosome markers, mtDNA, and population substructuring) and special circumstances (deficiency...

  10. Recommender system based on scarce information mining.

    Science.gov (United States)

    Lu, Wei; Chung, Fu-Lai; Lai, Kunfeng; Zhang, Liang

    2017-09-01

    Guessing what user may like is now a typical interface for video recommendation. Nowadays, the highly popular user generated content sites provide various sources of information such as tags for recommendation tasks. Motivated by a real world online video recommendation problem, this work targets at the long tail phenomena of user behavior and the sparsity of item features. A personalized compound recommendation framework for online video recommendation called Dirichlet mixture probit model for information scarcity (DPIS) is hence proposed. Assuming that each clicking sample is generated from a representation of user preferences, DPIS models the sample level topic proportions as a multinomial item vector, and utilizes topical clustering on the user part for recommendation through a probit classifier. As demonstrated by the real-world application, the proposed DPIS achieves better performance in accuracy, perplexity as well as diversity in coverage than traditional methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Current Trends in Radiation Protection Recommendations

    International Nuclear Information System (INIS)

    Gomaa, M.A.

    2008-01-01

    The third generation of the ICRP recommendations was adopted in April 2007. The recommendations rely on situations (planned, emergency and existing), individual (occupational, public and patient) and radiation protection system (justification, optimization and dose limits). In the present work attention is paid to discuss the new recommendations and role of IAEA in updating its Basic Safety Standards for protection against ionizing radiation and safety of radiation sources and its impact for the national regulations

  12. Panorama of recommender systems to support learning

    OpenAIRE

    Drachsler, Hendrik; Verbert, Katrien; Santos, Olga; Manouselis, Nikos

    2015-01-01

    This chapter presents an analysis of recommender systems in Technology-Enhanced Learning along their 15 years existence (2000-2014). All recommender systems considered for the review aim to support educational stakeholders by personalising the learning process. In this meta-review 82 recommender systems from 35 different countries have been investigated and categorised according to a given classification framework. The reviewed systems have been classified into 7 clusters according to their c...

  13. Web Page Recommendation Using Web Mining

    OpenAIRE

    Modraj Bhavsar; Mrs. P. M. Chavan

    2014-01-01

    On World Wide Web various kind of content are generated in huge amount, so to give relevant result to user web recommendation become important part of web application. On web different kind of web recommendation are made available to user every day that includes Image, Video, Audio, query suggestion and web page. In this paper we are aiming at providing framework for web page recommendation. 1) First we describe the basics of web mining, types of web mining. 2) Details of each...

  14. Smart Mirror: Intelligent Makeup Recommendation and Synthesis

    OpenAIRE

    Nguyen, Tam V.; Liu, Luoqi

    2017-01-01

    The female facial image beautification usually requires professional editing softwares, which are relatively difficult for common users. In this demo, we introduce a practical system for automatic and personalized facial makeup recommendation and synthesis. First, a model describing the relations among facial features, facial attributes and makeup attributes is learned as the makeup recommendation model for suggesting the most suitable makeup attributes. Then the recommended makeup attributes...

  15. Rating Methods for Proactive Recommendation on Smartwatches

    OpenAIRE

    Janosch Maier, Wolfgang Wörndl

    2015-01-01

    This paper analyzes possible interaction methods for using a recommender system on a smartwatch. As prerequisite, we describe interaction patterns currently used by Android Wear applications. Based on a prototype implementation the interaction methods action buttons, two button card and swipes are compared against each other. In a user study, 31 participating students were asked to rate restaurant recommendations offered in the setting of a context-aware, proactive recommender system. For eac...

  16. Learning Points and Routes to Recommend Trajectories

    OpenAIRE

    Chen, Dawei; Ong, Cheng Soon; Xie, Lexing

    2016-01-01

    The problem of recommending tours to travellers is an important and broadly studied area. Suggested solutions include various approaches of points-of-interest (POI) recommendation and route planning. We consider the task of recommending a sequence of POIs, that simultaneously uses information about POIs and routes. Our approach unifies the treatment of various sources of information by representing them as features in machine learning algorithms, enabling us to learn from past behaviour. Info...

  17. Recommendation advertising method based on behavior retargeting

    Science.gov (United States)

    Zhao, Yao; YIN, Xin-Chun; CHEN, Zhi-Min

    2011-10-01

    Online advertising has become an important business in e-commerce. Ad recommended algorithms are the most critical part in recommendation systems. We propose a recommendation advertising method based on behavior retargeting which can avoid leakage click of advertising due to objective reasons and can observe the changes of the user's interest in time. Experiments show that our new method can have a significant effect and can be further to apply to online system.

  18. BROND: USSR recommended evaluated neutron data library

    International Nuclear Information System (INIS)

    Manokhin, V.N.

    1988-03-01

    BROND is the recommended evaluated data library of the USSR for neutron induced nuclear reactions. It is a computer library recorded on magnetic tape presented in the internationally recommended format ENDF-5. It contains 65 files with recommended data for 65 elements or isotopes. For each file the present report gives a summary documentation on the contents, the evaluation methods and the originators of the files. (author). Refs

  19. ICRP-26, the recommendations on radiological protection

    International Nuclear Information System (INIS)

    Jun, J.S.

    1983-01-01

    Since the last ICRP recommendations on radiological protection was pubished in 1966 as it's publication 9, the revised edition of the recommendations had first been published in 1977, accommodating up-to-date knowledge of radiobiology and operational experiences of radiation protection built up for over a decade. In this article, the new version of the recommendations is reviewed in comparison with those of the publication 9, while the corrections and modifications made afterward are introduced together with the recent trends and responses of the experts in various countries for the pracical adoption or legislation of the recommendations. (Author)

  20. Uncovering the information core in recommender systems

    Science.gov (United States)

    Zeng, Wei; Zeng, An; Liu, Hao; Shang, Ming-Sheng; Zhou, Tao

    2014-08-01

    With the rapid growth of the Internet and overwhelming amount of information that people are confronted with, recommender systems have been developed to effectively support users' decision-making process in online systems. So far, much attention has been paid to designing new recommendation algorithms and improving existent ones. However, few works considered the different contributions from different users to the performance of a recommender system. Such studies can help us improve the recommendation efficiency by excluding irrelevant users. In this paper, we argue that in each online system there exists a group of core users who carry most of the information for recommendation. With them, the recommender systems can already generate satisfactory recommendation. Our core user extraction method enables the recommender systems to achieve 90% of the accuracy of the top-L recommendation by taking only 20% of the users into account. A detailed investigation reveals that these core users are not necessarily the large-degree users. Moreover, they tend to select high quality objects and their selections are well diversified.

  1. OMB Recommended vs Approved Operating Budget

    Data.gov (United States)

    Montgomery County of Maryland — This dataset includes the Fiscal Year 2015 County Executive Recommended and County Council Approved operating budgets for Montgomery County, for comparison purposes....

  2. Findings of the Marshall Islands nationwide radiological study

    International Nuclear Information System (INIS)

    McEwan, A.C.

    1996-01-01

    Full text: The Marshall Islands were affected by nuclear weapon tests carried out over the period 1946-1958, and particularly from the Bravo detonation on 1 March 1954, which deposited heavy fallout on the islands of Rongelap atoll about 100 miles to the east of Bikini. Surveys of residual radioactivity of the northern atolls of the Marshalls group had been carried out by the US Department of Energy, but continuing concerns about health effects of exposure to fallout, particularly thyroid disease, led the Marshall Islands government in 1989 to set up a study of residual radioactivity across the entire country. A study of residual radioactivity on all significant atolls and islands was carried out by ground surveys during 1990-94. The study was supervised by an international panel of 5 non US scientists. The measurements included portable gamma spectrometer measurements at points on a grid pattern, with associated soil samples and periodic soil profile and vegetation samples. From these measurements external exposure rates from deposited fallout have been calculated, and estimates made of the ingestion doses which might be received by resident populations consuming diets made up of differing amounts of locally produced foodstuffs. On the basis of a survey of dietary intake by a Rongelap community a current diet (containing 18% of foods from local sources) and a more traditional diet (75% from local sources) were used for comparison purposes. Measurements were made on 432 islands of the 29 atolls and 5 islands that make up the Marshalls group. Atolls in the latitude range 9-12 degrees north have Cs-137 soil concentrations which are elevated above levels expected from global fallout. Over 90% of the radiation dose from residual fallout is attributable to Cs-137, and arises primarily from dietary intake. Doses to actual or hypothetical residents are about 4 times greater for traditional as compared with current diets. For four atolls there are some islands where

  3. Context-aware recommender system based on ontology for recommending tourist destinations at Bandung

    Science.gov (United States)

    Rizaldy Hafid Arigi, L.; Abdurahman Baizal, Z. K.; Herdiani, Anisa

    2018-03-01

    Recommender System is software that is able to provide personalized recommendation suits users’ needs. Recommender System has been widely implemented in various domains, including tourism. One approach that can be done for more personalized recommendations is the use of contextual information. This paper proposes a context aware recommender based ontology system in the tourism domain. The system is capable of recommending tourist destinations by using user preferences of the categories of tourism and contextual information such as user locations, weather around tourist destinations and close time of destination. Based on the evaluation, the system has accuracy of of 0.94 (item recommendation precision evaluated by expert) and 0.58 (implicitly from system-end user interaction). Based on the evaluation of user satisfaction, the system provides a satisfaction level of more than 0.7 (scale 0 to 1) for speed factors for providing liked recommendations (PE), informative description of recommendations (INF) and user trust (TR).

  4. Recommender Systems in Technology Enhanced Learning

    NARCIS (Netherlands)

    Manouselis, Nikos; Drachsler, Hendrik; Verbert, Katrien; Santos, Olga

    2010-01-01

    Manouselis, N., Drachsler, H., Verbert, K., & Santos, C. S. (Eds.) (2010). Recommender System in Technology Enhanced Learning. Elsevier Procedia Computer Science: Volume 1, Issue 2. Proceedings of the 1st Workshop on Recommender Systems for Technology Enhanced Learning (RecSysTEL). September, 29-30,

  5. Personalized Recommender System for Digital Libraries

    Science.gov (United States)

    Omisore, M. O.; Samuel, O. W.

    2014-01-01

    The huge amount of information available online has given rise to personalization and filtering systems. Recommender systems (RS) constitute a specific type of information filtering technique that present items according to user's interests. In this research, a web-based personalized recommender system capable of providing learners with books that…

  6. Recommendations for hip fracture management in Slovenia

    Directory of Open Access Journals (Sweden)

    Radko Komadina

    2012-03-01

    Full Text Available Professional societies for traumatology, osteology and physiatrics have written the recommendations for management of acute hip fracture in the elderly in Slovenia, which include acute surgical treatment, medical rehabilitation and secondary prevention with treatment of osteoporosis. The recommendations were adopted by the Board for Surgery at the Ministry of Health of the Republic of Slovenia in June and September 2011.

  7. DEVELOPMENT OF A GENERIC RECOMMENDER SYSTEM

    Directory of Open Access Journals (Sweden)

    Dan Munteanu

    2004-12-01

    Full Text Available his paper presents a recommender system for textual documents taken from web (given as bookmarks. The system uses for classification a combination of content, event and collaborative filters and for recommendation a modified Pearson-r algorithm. It uses implicit and explicit feedback for evaluating documents.

  8. 40 CFR 231.5 - Recommended determination.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Recommended determination. 231.5... 404(c) PROCEDURES § 231.5 Recommended determination. (a) The Regional Administrator or his designee... public notice of the proposed determination, either withdraw the proposed determination or prepare a...

  9. Global recommendations on physical activity for health

    Science.gov (United States)

    ... кий Español Global Strategy on Diet, Physical Activity and Health Menu Diet, Physical Activity & Health Global strategy development ... obesity Documents & publications Related links Global recommendations on physical activity for health WHO developed the "Global Recommendations on Physical Activity ...

  10. 45 CFR 1616.4 - Recommendations.

    Science.gov (United States)

    2010-10-01

    ... recipient shall similarly notify and seek recommendations from other organizations, deemed appropriate by the recipient, that have knowledge of the legal needs of persons in the community unable to afford... § 1616.4 Recommendations. (a) Before filling an attorney position, a recipient shall notify the organized...

  11. Policy Recommendations on Decentralization, Local Power and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-12-22

    Policy Recommendations on Decentralization, Local Power and Women's Rights. December 22, 2010. Image. The present document comprises a set of policy recommendations that define a global agenda on gender and decentralization. It emerged from the analysis and experiences shared during the Conference and the ...

  12. A remarkable sea-level drop and relevant biotic responses across the Guadalupian-Lopingian (Permian) boundary in low-latitude mid-Panthalassa: Irreversible changes recorded in accreted paleo-atoll limestones in Akasaka and Ishiyama, Japan

    Science.gov (United States)

    Kofukuda, Daisuke; Isozaki, Yukio; Igo, Hisayoshi

    2014-03-01

    The Capitanian (Upper Guadalupian) to Wuchiapingian (Lower Lopingian) shallow-marine limestones at Akasaka and Ishiyama in central Japan record unique aspects of the extinction-related Guadalupian-Lopingian boundary (G-LB) interval. The ca. 140 m-thick Akasaka Limestone consists of the Capitanian black limestone (Unit B; 112 m) and the Wuchiapingian light gray dolomitic limestone (Unit W; 21 m), with a black/white striped limestone (Unit S; 9 m) between them. The G-LB horizon is assigned at the base of Unit W, on the basis of the first occurrence of the Wuchiapingian fusulines. The Capitanian Unit B and the Wuchiapingian Unit W were deposited mostly in the subtidal zone of a lagoon, whereas the intervened Unit S and the lowermost Unit W were in the intertidal zone. A hiatus with a remarkable erosional feature was newly identified at the top of Unit S. These records indicate that the sea-level has dropped significantly around the G-LB to have exposed the top of the atoll complex above the sea-level. The Ishiyama Limestone, located ca. 10 km to the north of the Akasaka limestone, retains almost the same depositional records. The extinction of large-tested fusuline (Yabeina) and large bivalves (Alatoconchidae) occurred in the upper part of Unit B, and the overlying 20 m-thick limestone (the uppermost Unit B and Unit S) below the hiatus represents a unique barren interval. The upper half of the barren interval is more depleted in fossils than the lower half, and this likely represents a duration of the severest environmental stress(es) for the shallow-marine protists/animals on the mid-oceanic paleo-atoll complex. Small-tested fusulines re-appeared at the base of Unit W above the hiatus. These facts prove that the elimination of shallow-marine biota occurred during the Capitanian shallowing of Akasaka paleo-atoll before the subaerial exposure/erosion across the G-LB. The overall shallowing and the development of such a clear hiatus at the top of a mid-oceanic seamount

  13. Concentrations of radionuclides in reef and lagoon pelagic fish from the Marshall Islands

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Eagle, R.J.; Wong, K.M.; Jokela, T.A.; Brunk, J.L.; Marsh, K.V.

    1981-07-01

    A radiological survey was conducted from September through November of 1978 to assess the concentrations of persistent man-made radionuclides in the terrestrial and marine environments of 11 atolls and 2 islands of the Northern Marshall Islands. The atolls and islands include Rongelap, Utirik, Taka, Bikar, Rongerik, Ailinginae, Likiep, Jemo, Ailuk, Mejet, Wotho, Ujelang and Bikini. Over 4000 terrestrial and marine samples were collected for radionuclide analysis from 76 different islands. Soils, vegetation, indigenous animals, and cistern and groundwater were collected from the islands. Reef fish, pelagic species, clams, lagoon water, and sediments were obtained from the lagoons. A report is given of all available concentration data for 137 Cs, 90 Sr, /sup 239+240/Pu, 238 Pu, 241 Am as well as naturally occurring 40 K and other gamma emitting radionuclides in tissues and organs of different species of fish collected from the atolls

  14. Receiving recommendations and providing feedback : the user-experience of a recommender system

    NARCIS (Netherlands)

    Knijnenburg, B.P.; Willemsen, M.C.; Hirtbach, S.; Buccafurri, F.; Semeraro, G.

    2010-01-01

    This paper systematically evaluates the user experience of a recommender system. Using both behavioral data and subjective measures of user experience, we demonstrate that choice satisfaction and system effectiveness increase when a system provides personalized recommendations (compared to the same

  15. A Sentiment-Enhanced Hybrid Recommender System for Movie Recommendation: A Big Data Analytics Framework

    Directory of Open Access Journals (Sweden)

    Yibo Wang

    2018-01-01

    Full Text Available Movie recommendation in mobile environment is critically important for mobile users. It carries out comprehensive aggregation of user’s preferences, reviews, and emotions to help them find suitable movies conveniently. However, it requires both accuracy and timeliness. In this paper, a movie recommendation framework based on a hybrid recommendation model and sentiment analysis on Spark platform is proposed to improve the accuracy and timeliness of mobile movie recommender system. In the proposed approach, we first use a hybrid recommendation method to generate a preliminary recommendation list. Then sentiment analysis is employed to optimize the list. Finally, the hybrid recommender system with sentiment analysis is implemented on Spark platform. The hybrid recommendation model with sentiment analysis outperforms the traditional models in terms of various evaluation criteria. Our proposed method makes it convenient and fast for users to obtain useful movie suggestions.

  16. A Sentiment-Enhanced Hybrid Recommender System for Movie Recommendation: A Big Data Analytics Framework

    OpenAIRE

    Wang, Yibo; Wang, Mingming; Xu, Wei

    2018-01-01

    Movie recommendation in mobile environment is critically important for mobile users. It carries out comprehensive aggregation of user’s preferences, reviews, and emotions to help them find suitable movies conveniently. However, it requires both accuracy and timeliness. In this paper, a movie recommendation framework based on a hybrid recommendation model and sentiment analysis on Spark platform is proposed to improve the accuracy and timeliness of mobile movie recommender system. In the propo...

  17. Science and Technology Review July/August 2010

    Energy Technology Data Exchange (ETDEWEB)

    Blobaum, K M

    2010-05-27

    This issue has the following articles: (1) Deterrence with a Minimum Nuclear Stockpile - Commentary by Bruce T. Goodwin; (2) Enhancing Confidence in the Nation's Nuclear Stockpile - Livermore experts are participating in a national effort aimed at predicting how nuclear weapon materials and systems will likely change over time; (3) Narrowing Uncertainties - For climate modeling and many other fields, understanding uncertainty, or margin of error, is critical; (4) Insight into a Deadly Disease - Laboratory experiments reveal the pathogenesis of tularemia in host cells, bringing scientists closer to developing a vaccine for this debilitating disease. (5) Return to Rongelap - On the Rongelap Atoll, Livermore scientists are working to minimize radiological exposure for natives now living on or wishing to return to the islands.

  18. Training Research: Practical Recommendations for Maximum Impact

    Science.gov (United States)

    Beidas, Rinad S.; Koerner, Kelly; Weingardt, Kenneth R.; Kendall, Philip C.

    2011-01-01

    This review offers practical recommendations regarding research on training in evidence-based practices for mental health and substance abuse treatment. When designing training research, we recommend: (a) aligning with the larger dissemination and implementation literature to consider contextual variables and clearly defining terminology, (b) critically examining the implicit assumptions underlying the stage model of psychotherapy development, (c) incorporating research methods from other disciplines that embrace the principles of formative evaluation and iterative review, and (d) thinking about how technology can be used to take training to scale throughout all stages of a training research project. An example demonstrates the implementation of these recommendations. PMID:21380792

  19. New recommendations for building in tropical climates

    Energy Technology Data Exchange (ETDEWEB)

    Waal, H.B. de (ISOVER BV, Cappelle a/d IJssel (Netherlands))

    1993-07-01

    Traditional recommendations for building a thermally efficient or comfortable building in a tropical climate are briefly summarized. They suffer from three main drawbacks; they are not quantitative, partly incorrect and only for two climates; the hot dry and the warm humid. A new climate classification, made up of forty tropical climates is presented. Eight building elements, which affect the thermal system of a building, are distinguished. The method by which the new recommendations are derived, is discussed. The new recommendations are briefly presented. (Author)

  20. Leveraging position bias to improve peer recommendation.

    Directory of Open Access Journals (Sweden)

    Kristina Lerman

    Full Text Available With the advent of social media and peer production, the amount of new online content has grown dramatically. To identify interesting items in the vast stream of new content, providers must rely on peer recommendation to aggregate opinions of their many users. Due to human cognitive biases, the presentation order strongly affects how people allocate attention to the available content. Moreover, we can manipulate attention through the presentation order of items to change the way peer recommendation works. We experimentally evaluate this effect using Amazon Mechanical Turk. We find that different policies for ordering content can steer user attention so as to improve the outcomes of peer recommendation.