Science.gov

Sample records for dwarf surf clam

  1. 50 CFR 648.72 - Minimum surf clam size.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Minimum surf clam size. 648.72 Section 648... Atlantic Surf Clam and Ocean Quahog Fisheries § 648.72 Minimum surf clam size. (a) Minimum length. The minimum length for surf clams is 4.75 inches (12.065 cm). (b) Determination of compliance. No more than...

  2. 50 CFR 648.72 - Minimum surf clam size.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... surfclam and or ocean quahog quotas that differ from the annual quotas specified for the current 3-year... Atlantic Surf Clam and Ocean Quahog Fisheries § 648.72 Minimum surf clam size. Link to an amendment... the convenience of the user, the revised text is set forth as follows: § 648.72 Surfclam and...

  3. The antioxidant potential of the New Zealand surf clams.

    PubMed

    Odeleye, Tinu; Li, Yan; White, William Lindsey; Nie, Shaoping; Chen, Shuping; Wang, Junqiao; Lu, Jun

    2016-08-01

    The antioxidant action of three New Zealand surf clams was evaluated for the first time. Aqueous (cd) and ethanolic extracts from Diamond shell - Crassula aequilatera, Storm shell - Mactra murchisoni, and Tua tua - Paphies donacina were studied for their antioxidant potentials using two in vitro assays. The ethanolic extracts were further fractioned into four parts; petroleum ether (pe), ethyl acetate (ea), n-butanol (nb), and the final aqueous fraction (w). Comparing among all fractions tested, the ea fraction of P. donacina showed the strongest free radical scavenging power, with a radical scavenging activity of 76.14% at 20μg/mL. The ea fraction of C. aequilatera had the highest copper reducing activity with an absorbance of 1.596 at 20μg/mL. Results from this study suggest that some bioactive compounds with significant antioxidant effects may exist in the New Zealand surf clams, and could potentially reduce oxidative stress to deliver health benefits or to produce functional foods. PMID:26988487

  4. 76 FR 65180 - Proposed Information Collection; Comment Request; Application to Shuck Surf Clams/Ocean Quahogs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-20

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Proposed Information Collection; Comment Request; Application to Shuck Surf Clams/Ocean Quahogs at Sea AGENCY: National Oceanic and Atmospheric...

  5. The influence of developmental stages and protective additives on cryopreservation of surf clam (Spisula sachalinensis) larvae.

    PubMed

    Choi, Youn Hee; Lee, Jeong Yong; Chang, Young Jin

    2008-07-01

    This study was performed to find out the optimal larval stage and the most desirable protective additives for cryopreservation of surf clam, Spisula sachalinensis larvae. The survival rates of frozen-thawed larvae increased with post developmental stage. The highest value of 96.1 +/- 1.0% was achieved using umbo stage larva as developmental stage and 0.2 M sucrose as protective additive. PMID:19195381

  6. Transformation of paralytic shellfish poisoning toxins in UK surf clams (Spisula solida) for targeted production of reference materials.

    PubMed

    Turner, Andrew D; Lewis, Adam M; O'Neil, Alison; Hatfield, Robert G

    2013-04-01

    The periodic occurrence of Paralytic Shellfish Poisoning (PSP) toxins in UK surf clams and the recent move away from biological assays for PSP testing resulted in the need to determine method performance characteristics for the replacement analytical method in this species. With the requirement for laboratory reference materials to aid this validation together with known issues relating to toxin transformation in live clams and homogenised tissue, there was the need to assess the toxin transformation characteristics of PSP toxins in surf clam tissue. Initial work examined the rates of toxin transformation in UK surf clam tissue incubated with toxin standards, showing rapid transformation of N-sulfocarbamoyl toxins with slower transformation of carbamate toxins. Full transformational pathways were determined using a combination of three different analytical methods and confirmed the major expected transformations involving decarbamoylation, with some evidence for additional reaction pathways. Results obtained from the analysis of surf clam and oyster tissues incubated with varying concentrations of toxic Alexandrium algae highlighted expected transformation reactions, although significant differences were observed in the extent of the transformations amongst the range of toxins studied, with less efficient transformation of N-hydroxylated toxins as compared with other carbamate and N-sulfocarbamoyl toxins. Analysis of PSP-toxic incurred oyster, scallop and mussel tissues incubated with variable proportions of surf clam tissue showed large differences in the extent of the transformations. Total conversion of N-sulfocarbamoyl toxins was confirmed at low relative proportions of surf clam tissue in all three species, whereas transformation of carbamate toxins was found to occur only in the presence of higher proportions of surf clam tissue in oysters and mussels in comparison with scallops. Results enabled the production of three laboratory reference materials prepared

  7. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (Mid-Atlantic). Surf Clam

    SciTech Connect

    Fay, C.W.; Neves, R.J.; Pardue, G.B.

    1983-10-01

    The surf clam (Spisula solidissima) is a dominant clam species in the mid-Atlantic region, and contributed 71.8% of all clam meats consumed in the United States between 1970 and 1974; total landings in 1981 were 20.9 thousand metric tons (46.1 million lb). Surf clams live in the coastal zone from the Gulf of Maine to Cape Hatteras, North Carolina; they are most common in the breaker zone, but occur to depths of 70 m (230 ft). They reach sexual maturity in 2 years and spawn in the mid-Atlantic region from mid-July through mid-October, often with two spawning peaks per year. Larval stages are planktonic; upon settlement, they metamorphose into juvenile clams. Adults live buried in sandy or gravel substrates, with siphons extended above the bottom for feeding and respiration. Surf clams may live up to 25 years and reach a size of 225 mm (8.9 inches). Larvae tolerate water temperatures of 14/sup 0/ to 30/sup 0/F (57/sup 0/) to 86/sup 0/F), and salinities as low as 16 ppt. Adults tolerate 0/sup 0/ to 28/sup 0/C (32/sup 0/ to 82/sup 0/F) and 12.5 ppt salinity or higher. Depletion of dissolved oxygen in ocean bottom waters was the major cause for large-scale surf clam mortalities off New York and New Jersey over the last two decades. Sewage, sludge, and heavy metals often cause accumulation of toxic materials in surf clam meats and force closure of beds to fishing to prevent human consumption of these toxic materials. 98 references, 2 figures, 3 tables.

  8. The calibration of photographic and spectroscopic films. The utilization of the digital image processor in the determination of aging of the surf clam (Spisula solidissima)

    NASA Technical Reports Server (NTRS)

    Peters, Kevin A.; Hammond, Ernest C., Jr.

    1987-01-01

    The age of the surf clam (Spisula solidissima) can be determined with the use of the Digital Image Processor. This technique is used in conjunction with a modified method for aging, refined by John Ropes of the Woods Hole Laboratory, Massachusetts. This method utilizes a thinned sectioned chondrophore of the surf clam which contains annual rings. The rings of the chondrophore are then counted to determine age. By digitizing the chondrophore, the Digital Image Processor is clearly able to separate these annual rings more accurately. This technique produces an easier and more efficient way to count annual rings to determine the age of the surf clam.

  9. Performance Characteristics of AOAC Method 2005.06 for the Determination of Paralytic Shellfish Toxins in Manila Clams, European Otter Clams, Grooved Carpet Shell Clams, Surf Clams, and Processed King Scallops.

    PubMed

    O'Neill, Alison; Turner, Andrew D

    2015-01-01

    An approach was developed for the verification of method performance of the AOAC 2005.06 LC-fluorescence detector (FLD) method for determination of paralytic shellfish poisoning (PSP) toxins in bivalve shellfish. This was developed following advice published by the Analytical Laboratory Accreditation Criteria Committee and applied to shellfish species that had not been previously subjected to a full single-laboratory validation scheme. The refined approach was developed following the need to assess performance in a number of shellfish species infrequently monitored through the UK statutory monitoring program, while reducing the impact and cost of the studies, most notably in terms of the use of valuable reference standards. The species assessed were manila clams (Ruditapes philippinarum), European otter clams (Lutraria lutraria), grooved carpet shell clams (R. decussatus), surf clams (Spisula solida), and king scallops (Pecten maximus) presented as adductor only or adductor plus roe. The method was assessed for sensitivity in terms of LOD and LOQ, toxin recovery, and method precision in each species. It incorporated the PSP toxins deemed toxic and/or prevalent in UK samples and commercially available as certified reference standards. The toxins studied included GTX1-5, dcSTX, STX, C1&2, and NEO. The toxins dcGTX2&3 were included for surf clams due to the prevalence of these toxins in this species as a result of toxin decarbamoylation. Method performance targets were met for each of the characteristics investigated. Consequently, the method was deemed fit for purpose for the screening and quantification of these clam and scallop species for PSP toxins by AOAC Method 2005.06 LC-FLD. PMID:26024751

  10. Effect of substrate component on the growth and survival of juvenile sunray surf clam (Mactra chinensis Philippi)

    NASA Astrophysics Data System (ADS)

    Zhang, Xuekai; Li, Zhuang; Huo, Zhongming; Yan, Xiwu; Yang, Feng; Liu, Hui; Zhang, Xingzhi

    2016-05-01

    Substrate is a critical environmental factor affecting the activity of bivalves. To examine the effect of the substrate component on the growth and survival of juvenile sunray surf clam (Mactra chinensis Philippi), a series of short-term experiments were conducted using a variety of substrates with different ratios of sand to mud. The experimental group cultured without substrate showed poor survival, with all juveniles died after day 20. The juveniles cultured in mud without sand showed a lower survival rate (25.54% ± 0.40% on day 45) than those in other groups. The juveniles cultured in sand without mud, or the mixtures of sand and mud with a ratio of 1:1 and 2:1, respectively, exhibited modest survival at day 45. Maximal weight gain rate (WGR), shell length growth rate (LGR), and specific growth rate (SGR) were observed when the sand concentration was 61.97%, 77.69%, and 64.64%, respectively. As the fast growth and high survival were observed when the sand to mud ratio was 1:1 (50% sand) and 2:1 (67% sand), a sand concentration of more than 50% is optimal. The optimal concentration of sand in the substrate for rearing juvenile sunray surf clams was 67% which resulted in the fastest growth and highest survival. These results can be used to developing a nursery/farming technique of improving the yield of sunray surf clams.

  11. Effect of substrate component on the growth and survival of juvenile sunray surf clam ( Mactra chinensis Philippi)

    NASA Astrophysics Data System (ADS)

    Zhang, Xuekai; Li, Zhuang; Huo, Zhongming; Yan, Xiwu; Yang, Feng; Liu, Hui; Zhang, Xingzhi

    2016-08-01

    Substrate is a critical environmental factor affecting the activity of bivalves. To examine the effect of the substrate component on the growth and survival of juvenile sunray surf clam ( Mactra chinensis Philippi), a series of short-term experiments were conducted using a variety of substrates with different ratios of sand to mud. The experimental group cultured without substrate showed poor survival, with all juveniles died after day 20. The juveniles cultured in mud without sand showed a lower survival rate (25.54% ± 0.40% on day 45) than those in other groups. The juveniles cultured in sand without mud, or the mixtures of sand and mud with a ratio of 1:1 and 2:1, respectively, exhibited modest survival at day 45. Maximal weight gain rate ( WGR), shell length growth rate ( LGR), and specific growth rate ( SGR) were observed when the sand concentration was 61.97%, 77.69%, and 64.64%, respectively. As the fast growth and high survival were observed when the sand to mud ratio was 1:1 (50% sand) and 2:1 (67% sand), a sand concentration of more than 50% is optimal. The optimal concentration of sand in the substrate for rearing juvenile sunray surf clams was 67% which resulted in the fastest growth and highest survival. These results can be used to developing a nursery/farming technique of improving the yield of sunray surf clams.

  12. Composition and Dynamics of the Nucleolinus, a Link between the Nucleolus and Cell Division Apparatus in Surf Clam (Spisula) Oocytes*

    PubMed Central

    Alliegro, Mark C.; Hartson, Steven; Alliegro, Mary Anne

    2012-01-01

    The nucleolinus is a little-known cellular structure, discovered over 150 years ago (Agassiz, L. (1857) Contributions to the Natural History of the United States of America, First Monograph, Part IIL, Little, Brown and Co., Boston) and thought by some investigators in the late 19th to mid-20th century to function in the formation of the centrosomes or spindle. A role for the nucleolinus in formation of the cell division apparatus has recently been confirmed in oocytes of the surf clam, Spisula solidissima (Alliegro, M. A., Henry, J. J., and Alliegro, M. C. (2010) Proc. Natl. Acad. Sci. U.S.A. 107, 13718–13723). However, we know so little about the composition and dynamics of this compartment, it is difficult to construct mechanistic hypotheses or even to be sure that prior reports were describing analogous structures in the cells of mammals, amphibians, plants, and other organisms where it was observed. Surf clam oocytes are an attractive model to approach this problem because the nucleolinus is easily visible by light microscopy, making it accessible by laser microsurgery as well as isolation by common cell fractionation techniques. In this report, we analyze the macromolecular composition of isolated Spisula nucleolini and examine the relationship of this structure to the nucleolus and cell division apparatus. Analysis of nucleolinar RNA and protein revealed a set of molecules that overlaps with but is nevertheless distinct from the nucleolus. The proteins identified were primarily ones involved in nucleic acid metabolism and cell cycle regulation. Monoclonal antibodies generated against isolated nucleolini revealed centrosomal forerunners in the oocyte cytoplasm. Finally, induction of damage to the nucleolinus by laser microsurgery altered the trafficking of α- and γ-tubulin after fertilization. These observations strongly support a role for the nucleolinus in cell division and represent our first clues regarding mechanism. PMID:22219192

  13. Population subdivision of the surf clam Mactra chinensis in the East China Sea: Changjiang River outflow is not the sole driver

    PubMed Central

    Ni, Gang; Ni, Lehai; Kong, Lingfeng; Yu, Hong

    2015-01-01

    The northwestern Pacific, characterized by unique tectonic and hydrological settings, has greatly intrigued marine phylogeographers. However, current studies mostly focus on the influence of Pleistocene isolation of sea basins in population structure of species in the region, leaving the contribution of other factors (such as freshwater outflow and environmental gradients) largely unexploited. Here we shed light on the question by investigating phylogeography of the surf clam Mactra chinensis in the East China Sea (ECS). Genetic information was acquired from 501 specimens collected from its main distribution in the region, represented by mitochondrial cytochrome oxidase I (COI) and nine polymorphic microsatellite loci. A shallow and star-like phylogeny was revealed for all COI haplotypes, indicating the origin of populations from a single refugium. Although no divergent lineages existed, population subdivision was detected in both data sets. The most striking pattern was the significant differentiation between populations north and south of a biogeographic boundary—the Changjiang Estuary, suggesting a barrier effect of the freshwater outflow to gene flow. For the northern group, substructure was revealed by COI result as one southernmost population was significant different from other ones. Clear latitude gradations in allele frequencies were revealed by microsatellite analyses, likely influenced by environmental gradient factors such as temperature. Our results demonstrate that genetic subdivision can arise for populations within the ECS despite they have a single origin, and multiple mechanisms including Changjiang River outflow, environmental gradient factors and life-history traits may act in combination in the process. PMID:26468432

  14. Population subdivision of the surf clam Mactra chinensis in the East China Sea: Changjiang River outflow is not the sole driver.

    PubMed

    Ni, Gang; Li, Qi; Ni, Lehai; Kong, Lingfeng; Yu, Hong

    2015-01-01

    The northwestern Pacific, characterized by unique tectonic and hydrological settings, has greatly intrigued marine phylogeographers. However, current studies mostly focus on the influence of Pleistocene isolation of sea basins in population structure of species in the region, leaving the contribution of other factors (such as freshwater outflow and environmental gradients) largely unexploited. Here we shed light on the question by investigating phylogeography of the surf clam Mactra chinensis in the East China Sea (ECS). Genetic information was acquired from 501 specimens collected from its main distribution in the region, represented by mitochondrial cytochrome oxidase I (COI) and nine polymorphic microsatellite loci. A shallow and star-like phylogeny was revealed for all COI haplotypes, indicating the origin of populations from a single refugium. Although no divergent lineages existed, population subdivision was detected in both data sets. The most striking pattern was the significant differentiation between populations north and south of a biogeographic boundary-the Changjiang Estuary, suggesting a barrier effect of the freshwater outflow to gene flow. For the northern group, substructure was revealed by COI result as one southernmost population was significant different from other ones. Clear latitude gradations in allele frequencies were revealed by microsatellite analyses, likely influenced by environmental gradient factors such as temperature. Our results demonstrate that genetic subdivision can arise for populations within the ECS despite they have a single origin, and multiple mechanisms including Changjiang River outflow, environmental gradient factors and life-history traits may act in combination in the process. PMID:26468432

  15. Delineation of surf scoter habitat in Chesapeake Bay, Maryland: macrobenthic and sediment composition of surf scoter feeding sites

    USGS Publications Warehouse

    Kidwell, D.M.; Perry, M.C.

    2005-01-01

    Surveys of surf scoters (Melanitta perspicillata) along the Atlantic coast of the United States have shown population declines in recent decades. The Chesapeake Bay has traditionally been a key wintering area for surf scoters. Past and present research has shown that bivalves constitute a major food item for seaducks in the Chesapeake Bay, with surf scoters feeding primarily on hooked mussel (Ischadium recurvum) and dwarf surf clam (Mulinia lateralis). Degraded water quality conditions in the Chesapeake Bay have been well documented and have been shown to greatly influence the composition of benthic communities. Large concentrations of feeding surf scoters (>500 individuals) in the Bay were determined through monthly boat surveys. Locations consistently lacking surf scoters were also determined. Macrobenthos were seasonally sampled at 3 locations containing scoters and 3 locations without scoters. A 1 kilometer square grid was superimposed over each location using GIS and sampling sites within the square were randomly chosen. Benthos were sampled at each site using SCUBA and a meter square quadrat. Biomass and size class estimates were determined for all bivalves within each kilometer square. Results indicated that scoter feeding sites contained significantly greater biomass of M. lateralis, I. recurvum, and Gemma gemma than locations where no scoters were present. Substrate differences were also detected, with scoter feeding sites being composed of a sand/shell mix while non-scoter sites consisted primarily of mud. This data indicates that surf scoters in the Chesapeake Bay are selecting areas with high densities of preferred food items, potentially maximizing there foraging energetics. In addition, two scoter feeding sites also contained a patchwork of eastern oyster (Crassostrea virginica) and oyster shell, on which much of the I. recurvum was attached. This suggests the possibility that surf scoters utilize eastern oyster habitat and the dramatic depletion of

  16. Surfing the vegetal pole in a small population: extracellular vertical transmission of an 'intracellular' deep-sea clam symbiont

    PubMed Central

    Igawa, Kanae; Tame, Akihiro; Kuroiwa, Tsuneyoshi; Kuroiwa, Haruko; Aoki, Yui; Takaki, Yoshihiro; Nagai, Yukiko; Ozawa, Genki; Yamamoto, Masahiro; Deguchi, Ryusaku; Fujikura, Katsunori; Maruyama, Tadashi; Yoshida, Takao

    2016-01-01

    Symbiont transmission is a key event for understanding the processes underlying symbiotic associations and their evolution. However, our understanding of the mechanisms of symbiont transmission remains still fragmentary. The deep-sea clam Calyptogena okutanii harbours obligate sulfur-oxidizing intracellular symbiotic bacteria in the gill epithelial cells. In this study, we determined the localization of their symbiont associating with the spawned eggs, and the population size of the symbiont transmitted via the eggs. We show that the symbionts are located on the outer surface of the egg plasma membrane at the vegetal pole, and that each egg carries approximately 400 symbiont cells, each of which contains close to 10 genomic copies. The very small population size of the symbiont transmitted via the eggs might narrow the bottleneck and increase genetic drift, while polyploidy and its transient extracellular lifestyle might slow the rate of genome reduction. Additionally, the extracellular localization of the symbiont on the egg surface may increase the chance of symbiont exchange. This new type of extracellular transovarial transmission provides insights into complex interactions between the host and symbiont, development of both host and symbiont, as well as the population dynamics underlying genetic drift and genome evolution in microorganisms. PMID:27293794

  17. Surfing the vegetal pole in a small population: extracellular vertical transmission of an 'intracellular' deep-sea clam symbiont.

    PubMed

    Ikuta, Tetsuro; Igawa, Kanae; Tame, Akihiro; Kuroiwa, Tsuneyoshi; Kuroiwa, Haruko; Aoki, Yui; Takaki, Yoshihiro; Nagai, Yukiko; Ozawa, Genki; Yamamoto, Masahiro; Deguchi, Ryusaku; Fujikura, Katsunori; Maruyama, Tadashi; Yoshida, Takao

    2016-05-01

    Symbiont transmission is a key event for understanding the processes underlying symbiotic associations and their evolution. However, our understanding of the mechanisms of symbiont transmission remains still fragmentary. The deep-sea clam Calyptogena okutanii harbours obligate sulfur-oxidizing intracellular symbiotic bacteria in the gill epithelial cells. In this study, we determined the localization of their symbiont associating with the spawned eggs, and the population size of the symbiont transmitted via the eggs. We show that the symbionts are located on the outer surface of the egg plasma membrane at the vegetal pole, and that each egg carries approximately 400 symbiont cells, each of which contains close to 10 genomic copies. The very small population size of the symbiont transmitted via the eggs might narrow the bottleneck and increase genetic drift, while polyploidy and its transient extracellular lifestyle might slow the rate of genome reduction. Additionally, the extracellular localization of the symbiont on the egg surface may increase the chance of symbiont exchange. This new type of extracellular transovarial transmission provides insights into complex interactions between the host and symbiont, development of both host and symbiont, as well as the population dynamics underlying genetic drift and genome evolution in microorganisms. PMID:27293794

  18. Molecular characterization of two kazal-type serine proteinase inhibitor genes in the surf clam Mesodesma donacium exposed to Vibrio anguillarum.

    PubMed

    Maldonado-Aguayo, Waleska; Núñez-Acuña, Gustavo; Valenzuela-Muñoz, Valentina; Chávez-Mardones, Jacqueline; Gallardo-Escárate, Cristian

    2013-06-01

    This study reports two kazal-type serine protease inhibitors (KPI) identified in a cDNA library from the surf clam Mesodesma donacium, and characterized through Rapid Amplification of cDNA Ends (RACE). The KPIs, denoted as MdSPI-1 and MdSPI-2, presented full sequences of 1139 bp and 781 bp respectively. MdSPI-1 had a 5'untranslated region (UTR) of 175 bp, a 3'UTR of 283 bp and an open reading frame (ORF) of 681 pb that encodes for 227 amino acids. MdSPI-2 showed a 5'UTR of 70 bp, a 3'UTR of 279 bp and an ORF of 432 bp that encodes for 144 amino acids. Both sequences presented two kazal-type tandem domains. Phylogenetic analysis of MdSPI-1 and MdSPI-2 shows a main clade composed by other bivalve species and closely related crustaceans. Real time PCR analysis showed that MdSPI-1 is mainly up-regulated in mantle, foot, gills and muscle tissues, while MdSPI-2 is expressed principally in foot tissue. Moreover, to evaluate the immune response of MdSPI-1 and MdSPI-2, infections with Vibrio anguillarum were performed. Herein, MdSPI-1 and MdSPI-2 transcription expression were significantly up-regulated at 2 and 8 h post-challenge. Our results suggest that MdSPI-1 and MdSPI-2 are important humoral factors of innate immunity in M. donacium. PMID:23528874

  19. Surf Tourism, Artificial Surfing Reefs, and Environmental Sustainability

    NASA Astrophysics Data System (ADS)

    Slotkin, Michael H.; Chambliss, Karen; Vamosi, Alexander R.; Lindo, Chris

    2009-07-01

    This paper explores the confluence of surf tourism, artificial surfing reefs, and sustainability. Surfing is an ascendant recreational and tourism industry and artificial surfing reefs are a new and innovative technology and product. Presented within the context of Florida's Space Coast, empirical details on surf tourism are discussed along with the possible implications for sustainability.

  20. Medical Aspects of Surfing.

    ERIC Educational Resources Information Center

    Renneker, Mark

    1987-01-01

    The medical aspects of surfing include ear and eye injuries and sprains and strains of the lower back and neck, as well as skin cancer from exposure to the sun. Treatment, rehabilitation, and prevention of these problems are discussed. Surfing is recommended as part of an exercise program for reasonably healthy people. (Author/MT)

  1. Surfing on the Spectrum

    ERIC Educational Resources Information Center

    Apel, Laura

    2007-01-01

    Israel Paskowitz loves surfing. As a former competitive surfer, he has spent much of his life in the ocean and absorbed in a community of athletes that share a special connection with the water. Surfing is often thought of as a spiritual hobby that brings peace and relaxation to those who experience it. However, it was not until Israel's son,…

  2. CLAMS Data and Information

    Atmospheric Science Data Center

    2016-06-14

    ... eastern seaboard from July 10 - August 3, 2001. CLAMS is an experiment designed to validate and improve EOS Terra satellite data products ... Lighthouse and Aircraft An Overview of the CLAMS Experiment Readme Files:  AirMISR Home Page ...

  3. Effects of predation by sea ducks on clam abundance in soft-bottom intertidal habitats

    USGS Publications Warehouse

    Lewis, Tyler; Esler, Daniel N.; Boyd, W. Sean

    2007-01-01

    Recent studies have documented strong, top-down predation effects of sea ducks on mussel populations in rocky intertidal communities. However, the impact of these gregarious predators in soft-bottom communities has been largely unexplored. We evaluated effects of predation by wintering surf scoters Melanitta perspicillata and white-winged scoters M. fusca on clam populations in soft-bottom intertidal habitats of the Strait of Georgia, British Columbia. Specifically, we documented spatial and temporal variation in clam density (clams m–2), scoter diet composition, and the consequences of scoter predation on clam abundance. Of the 3 most numerous clams, Manila clams Venerupis philippinarum and varnish clams Nuttallia obscurata were the primary prey items of both scoter species, while clams of the genus Macoma were rarely consumed by scoters. Between scoter arrival in the fall and departure in the spring, Manila clams decreased in density at most sample sites, while varnish clam densities did not change or declined slightly. Our estimates of numbers of clams consumed by scoters accounted for most of the observed declines in combined abundance of Manila and varnish clams, despite the presence of numerous other vertebrate and invertebrate species known to consume clams. For Macoma spp., we detected an over-winter increase in density, presumably due to growth of clams too small to be retained by our sieve (<5 mm) during fall sampling, in addition to the lack of predation pressure by scoters. These results illustrate the strong predation potential of scoters in soft-bottom intertidal habitats, as well as their potentially important role in shaping community structure.

  4. SURF: Submm User Reduction Facility

    NASA Astrophysics Data System (ADS)

    Jenness, Tim; Lightfoot, John

    2014-03-01

    SURF reduces data from the SCUBA instrument from the James Clerk Maxwell Telescope. Facilities are provided for reducing all the SCUBA observing modes including jiggle, scan and photometry modes. SURF uses the Starlink environment (ascl:1110.012).

  5. Shock-wave surfing

    SciTech Connect

    Laurence, Stuart J; Deiterding, Ralf

    2011-01-01

    A phenomenon referred to as shock-wave surfing , in which a body moves in such a way as to follow the shock wave generated by another upstream body, is investigated numerically and theoretically. This process can lead to the downstream body accumulating a significantly higher lateral velocity than would otherwise be possible, and thus is of importance in situations such as meteoroid fragmentation, in which the fragment separation behaviour following disruption is determined to a large extent by aerodynamic effects. The surfing effect is first investigated in the context of interactions between a sphere and a planar oblique shock. Numerical simulations are performed and a simple theoretical model is developed to determine the forces acting on the sphere. A phase-plane description is employed to elucidate features of the system dynamics. The theoretical model is then generalised to the more complex situation of aerodynamic interactions between two spheres, and, through comparisons with further computations, is shown to adequately predict, in particular, the final separation velocity of the surfing sphere in initially touching configurations. Both numerical simulations and theory indicate a strong influence of the body radius ratio on the separation process and predict a critical radius ratio for initially touching fragments that delineates entrainment of the smaller fragment within the larger fragment s shock from expulsion; this critical ratio also results in the most extended surfing. Further, these results show that an earlier prediction for the separation velocity to scale with the square root of the radius ratio does not accurately describe the separation behaviour. The theoretical model is then employed to investigate initial configurations with varying relative sphere positions and initial velocities. A phase-space description is also shown to be useful in elucidating the dynamics of the sphere-sphere system. With regard to meteoroid fragmentation, it is shown

  6. Surfing a magnetic wave

    NASA Astrophysics Data System (ADS)

    Dehandschoewercker, Eline; Quere, David; Clanet, Christophe

    2014-11-01

    Surfing is a free surface sport in which the athlete rides a wave standing on a board. However, any object plunged into the water or put on its surface is not always captured by an approaching wave, just like the classic example of a fisching float. So, a particle can be captured or not by a wave. Two regimes are defined: surf (captured) and drift (not captured). We focus on the question of the transition between these two regimes. Here we address the question with a magnetic wave. We have developed an experimental setup which allows the control of all relevant physical parameters. Liquid oxygen, which is paramagnetic and undergoes Leidenfrost effect, can be used to ensure magnetic and frictionless particles. A permanent magnet in translatory movement allows us to create a definite magnetic wave. We discuss the motion of oxygen drops deposited on an smooth and horizontal surface above an approaching magnet. First we show the existence of a critical speed below which drops are captured and determine how it depends on the velocity and intensity of the magnetic wave. Then we experimentally investigate the parameters that would affect the movement of drops in each regime. Finally, models have been developed to interpret magnetic drops motion and guarantee an efficient control.

  7. Termination Shock Surfing

    NASA Astrophysics Data System (ADS)

    Burrows, R. H.; Zank, G. P.; Webb, G. M.

    2009-11-01

    The recent Voyager 2 (V2) observations of the termination shock (TS) indicate that it is a plasma shock like no other in the heliosphere with dynamics and structure heavily influenced by the presence of an energized population of pickup ions (PUIs). The `unexpected' finding of a cold plasma in the heliosheath with very little heating of the solar wind suggests that the energy dissipated by the shock could be dominated by the acceleration of PUIs at the TS. We examine the 'shock surfing' mechanism at the test particle level, where multiply reflected ions (MRIs) gain energy from the motional electric field as a consequence of reflection from the cross-shockpotential, for a specific model of the TS3 (the third TS crossing measured by V2). The energization of PUI shell distributions at a stationary, perpendicular model of the TS3 indicate that shock surfing can provide substantial PUI acceleration and a dissipation mechanism at the TS. For a strong enough cross-shock potential and sufficiently narrow shock ramp MRI acceleration can account for the `missing' energy of the downstream solar wind plasma.

  8. Guide to Healthy Web Surfing

    MedlinePlus

    ... gov/medlineplus/healthywebsurfing.html MedlinePlus Guide to Healthy Web Surfing To use the sharing features on this ... the site, use caution. Focus on quality--All Web sites are not created equal Does the site ...

  9. Pneumomediastinum in a surf lifesaver.

    PubMed Central

    Fallon, K E; Foster, K

    1996-01-01

    Pneumomediastinum is an uncommon complication of sporting activity. The case of a young asthmatic surf lifesaver is reported in which several factors are thought to have been involved in the aetiology of his condition. Treatment was expectant and a full recovery was made over a short period. This is the first reported case of pneumomediastinum occurring following training for a surf belt race. PMID:9015603

  10. Physiological demands of competitive surfing.

    PubMed

    Farley, Oliver R L; Harris, Nigel K; Kilding, Andrew E

    2012-07-01

    This study was a performance analysis of surfing athletes during competitive surfing events in an attempt to inform the development of surfing-specific conditioning. Twelve nationally ranked surfers were fitted with heart rate (HR) monitors and global positioning system (GPS) units and videoed during the heats of 2 sanctioned competitions. Means and SDs represented the centrality and spread of analyzed data. From the 32 videos analyzed, the greatest amount of time spent during surfing was paddling (54 ± 6.3% of the total time) (% TT). The remaining stationary represented 28 ± 6.9% TT, wave riding, and paddling for a wave represented only 8 ± 2% TT and 4 ± 1.5% TT, respectively. Surfers spent 61 ± 7% of the total paddling bouts and 64 ± 6.8% of total stationary bouts between 1 and 10 seconds. The average speed recorded via the GPS for all the subjects was 3.7 ± 0.6 km·h(-1), with an average maximum speed of 33.4 ± 6.5 km·h(-1) (45 km·h(-1) was the highest speed recorded). The average distance covered was 1,605 ± 313 m. The mean HR during the surf competitions was 139 ± 11 b·min(-1) (64% HRmax), with a (mean) peak of 190 ± 12 b·min(-1) (87% HRmax). Sixty percent TT was spent between 56 and 74% of the age-predicted HR maximum (HRmax), 19% TT >46% HRmax, and approximately 3% TT >83% HRmax. Competitive surfing therefore involves intermittent high-intensity bouts of all out paddling intercalated with relatively short recovery periods and repeated bouts of low-intensity paddling, incorporating intermittent breath holding. Surfing-specific conditioning sessions should attempt to replicate such a profile. PMID:21986691

  11. Burrowing saves Lake Erie clams

    USGS Publications Warehouse

    Nichols, S. Jerrine; Wilcox, Douglas A.

    1997-01-01

    Freshwater unionid clams in North America have been virtually eliminated from waters that are colonized by zebra mussels. Near total mortality has been reported in western Lake Erie, but we have discovered a large population of native clams in a Lake Erie wetland that shows little sign of infestation. Field observations and laboratory experiments show that warm summer water temperatures and soft, silt-clay sediments trigger burowing by clams. This discourages infestation and physically removes any attached zebra mussels.

  12. WATERSHED INFORMATION - SURF YOUR WATERSHED

    EPA Science Inventory

    Surf Your Watershed is both a database of urls to world wide web pages associated with the watershed approach of environmental management and also data sets of relevant environmental information that can be queried. It is designed for citizens and decision makers across the count...

  13. 21 CFR 102.49 - Fried clams made from minced clams.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Fried clams made from minced clams. 102.49 Section... Nonstandardized Foods § 102.49 Fried clams made from minced clams. (a) The common or usual name of the food product that resembles and is of the same composition as fried clams, except that it is composed...

  14. 21 CFR 102.49 - Fried clams made from minced clams.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Fried clams made from minced clams. 102.49 Section... Nonstandardized Foods § 102.49 Fried clams made from minced clams. (a) The common or usual name of the food product that resembles and is of the same composition as fried clams, except that it is composed...

  15. 21 CFR 102.49 - Fried clams made from minced clams.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Fried clams made from minced clams. 102.49 Section... Nonstandardized Foods § 102.49 Fried clams made from minced clams. (a) The common or usual name of the food product that resembles and is of the same composition as fried clams, except that it is composed...

  16. 21 CFR 102.49 - Fried clams made from minced clams.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Fried clams made from minced clams. 102.49 Section... Nonstandardized Foods § 102.49 Fried clams made from minced clams. (a) The common or usual name of the food product that resembles and is of the same composition as fried clams, except that it is composed...

  17. 21 CFR 102.49 - Fried clams made from minced clams.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Fried clams made from minced clams. 102.49 Section... Nonstandardized Foods § 102.49 Fried clams made from minced clams. (a) The common or usual name of the food product that resembles and is of the same composition as fried clams, except that it is composed...

  18. Movements of wintering surf scoters: predator responses to different prey landscapes.

    PubMed

    Kirk, Molly; Esler, Daniel; Iverson, Samuel A; Boyd, W Sean

    2008-04-01

    The distribution of predators is widely recognized to be intimately linked to the distribution of their prey. Foraging theory suggests that predators will modify their behaviors, including movements, to optimize net energy intake when faced with variation in prey attributes or abundance. While many studies have documented changes in movement patterns of animals in response to temporal changes in food, very few have contrasted movements of a single predator species naturally occurring in dramatically different prey landscapes. We documented variation in the winter movements, foraging range size, site fidelity, and distribution patterns of a molluscivorous sea duck, the surf scoter (Melanitta perspicillata), in two areas of coastal British Columbia with very different shellfish prey features. Baynes Sound has extensive tidal flats with abundant clams, which are high-quality and temporally stable prey for scoters. Malaspina Inlet is a rocky fjord-like inlet where scoters consume mussels that are superabundant and easily accessible in some patches but are heavily depleted over the course of winter. We used radio telemetry to track surf scoter movements in both areas and found that in the clam habitats of Baynes Sound, surf scoters exhibited limited movement, small winter ranges, strong foraging site fidelity, and very consistent distribution patterns. By contrast, in mussel habitats in the Malaspina Inlet, surf scoters displayed more movement, larger ranges, little fidelity to specific foraging sites, and more variable distribution patterns. We conclude that features associated with the different prey types, particularly the higher depletion rates of mussels, strongly influenced seasonal space use patterns. These findings are consistent with foraging theory and confirm that predator behavior, specifically movements, is environmentally mediated. PMID:18210158

  19. Nontraumatic Myelopathy Associated With Surfing

    PubMed Central

    Avilés-Hernández, Israel; García-Zozaya, Inigo; DeVillasante, Jorge M

    2007-01-01

    Background/Objective: Ischemic nontraumatic spinal cord injury associated with surfing is a novel diagnosis believed to be related to prolonged spine hyperextension while lying prone on the surfboard. Only 9 cases have been documented. This report features possible risk factors, etiology, diagnostic imaging, and outcomes of surfer's myelopathy. Design: Case report. Results: A 37-year-old man developed T11 American Spinal Injury Association (ASIA) A paraplegia shortly after surfing. The clinical history and magnetic resonance imaging findings were compatible with an ischemic insult to the distal thoracic spinal cord. Our patient did not have any of the proposed risk factors associated with this condition, and, contrary to most reports, he sustained a complete spinal cord lesion without neurological recovery by 8 weeks post injury. Conclusions: Surfer's myelopathy, because of its proposed mechanism of injury, is amenable to medical intervention. Increased awareness of this condition may lead to early recognition and treatment, which should contribute to improved neurological outcomes. PMID:17684897

  20. Composition, shell strength, and metabolizable energy of Mulinia lateralis and Ischadium recurvum as food for wintering surf scoters (Melanitta perspicillata)

    USGS Publications Warehouse

    Berlin, Alicia; Perry, Matthew; Kohn, R.A.; Paynter, K.T., Jr.; Ottinger, Mary Ann

    2015-01-01

    Decline in surf scoter (Melanitta perspicillata) waterfowl populations wintering in the Chesapeake Bay has been associated with changes in the availability of benthic bivalves. The Bay has become more eutrophic, causing changes in the benthos available to surf scoters. The subsequent decline in oyster beds (Crassostrea virginica) has reduced the hard substrate needed by the hooked mussel (Ischadium recurvum), one of the primary prey items for surf scoters, causing the surf scoter to switch to a more opportune species, the dwarf surfclam (Mulinia lateralis). The composition (macronutrients, minerals, and amino acids), shell strength (N), and metabolizable energy (kJ) of these prey items were quantified to determine the relative foraging values for wintering scoters. Pooled samples of each prey item were analyzed to determine composition. Shell strength (N) was measured using a shell crack compression test. Total collection digestibility trials were conducted on eight captive surf scoters. For the prey size range commonly consumed by surf scoters (6-12 mm for M. lateralis and 18-24 mm for I. recurvum), I. recurvum contained higher ash, protein, lipid, and energy per individual organism than M. lateralis. I. recurvum required significantly greater force to crack the shell relative to M. lateralis. No difference in metabolized energy was observed for these prey items in wintering surf scoters, despite I. recurvum's higher ash content and harder shell than M. lateralis. Therefore, wintering surf scoters were able to obtain the same amount of energy from each prey item, implying that they can sustain themselves if forced to switch prey.

  1. Composition, Shell Strength, and Metabolizable Energy of Mulinia lateralis and Ischadium recurvum as Food for Wintering Surf Scoters (Melanitta perspicillata).

    PubMed

    Wells-Berlin, Alicia M; Perry, Matthew C; Kohn, Richard A; Paynter, Kennedy T; Ottinger, Mary Ann

    2015-01-01

    Decline in surf scoter (Melanitta perspicillata) waterfowl populations wintering in the Chesapeake Bay has been associated with changes in the availability of benthic bivalves. The Bay has become more eutrophic, causing changes in the benthos available to surf scoters. The subsequent decline in oyster beds (Crassostrea virginica) has reduced the hard substrate needed by the hooked mussel (Ischadium recurvum), one of the primary prey items for surf scoters, causing the surf scoter to switch to a more opportune species, the dwarf surfclam (Mulinia lateralis). The composition (macronutrients, minerals, and amino acids), shell strength (N), and metabolizable energy (kJ) of these prey items were quantified to determine the relative foraging values for wintering scoters. Pooled samples of each prey item were analyzed to determine composition. Shell strength (N) was measured using a shell crack compression test. Total collection digestibility trials were conducted on eight captive surf scoters. For the prey size range commonly consumed by surf scoters (6-12 mm for M. lateralis and 18-24 mm for I. recurvum), I. recurvum contained higher ash, protein, lipid, and energy per individual organism than M. lateralis. I. recurvum required significantly greater force to crack the shell relative to M. lateralis. No difference in metabolized energy was observed for these prey items in wintering surf scoters, despite I. recurvum's higher ash content and harder shell than M. lateralis. Therefore, wintering surf scoters were able to obtain the same amount of energy from each prey item, implying that they can sustain themselves if forced to switch prey. PMID:25978636

  2. Composition, Shell Strength, and Metabolizable Energy of Mulinia lateralis and Ischadium recurvum as Food for Wintering Surf Scoters (Melanitta perspicillata)

    PubMed Central

    Wells-Berlin, Alicia M.; Perry, Matthew C.; Kohn, Richard A.; Paynter, Kennedy T.; Ottinger, Mary Ann

    2015-01-01

    Decline in surf scoter (Melanitta perspicillata) waterfowl populations wintering in the Chesapeake Bay has been associated with changes in the availability of benthic bivalves. The Bay has become more eutrophic, causing changes in the benthos available to surf scoters. The subsequent decline in oyster beds (Crassostrea virginica) has reduced the hard substrate needed by the hooked mussel (Ischadium recurvum), one of the primary prey items for surf scoters, causing the surf scoter to switch to a more opportune species, the dwarf surfclam (Mulinia lateralis). The composition (macronutrients, minerals, and amino acids), shell strength (N), and metabolizable energy (kJ) of these prey items were quantified to determine the relative foraging values for wintering scoters. Pooled samples of each prey item were analyzed to determine composition. Shell strength (N) was measured using a shell crack compression test. Total collection digestibility trials were conducted on eight captive surf scoters. For the prey size range commonly consumed by surf scoters (6–12 mm for M. lateralis and 18–24 mm for I. recurvum), I. recurvum contained higher ash, protein, lipid, and energy per individual organism than M. lateralis. I. recurvum required significantly greater force to crack the shell relative to M. lateralis. No difference in metabolized energy was observed for these prey items in wintering surf scoters, despite I. recurvum’s higher ash content and harder shell than M. lateralis. Therefore, wintering surf scoters were able to obtain the same amount of energy from each prey item, implying that they can sustain themselves if forced to switch prey. PMID:25978636

  3. Experimental challenges of wild Manila clams with Perkinsus species isolated from naturally infected wild Manila clams.

    PubMed

    Waki, Tsukasa; Shimokawa, Jun; Watanabe, Shinji; Yoshinaga, Tomoyoshi; Ogawa, Kazuo

    2012-09-15

    Manila clams, Ruditapes philippinarum, are widely harvested in the coastal waters in Japan. However, there have been significant decreases in the populations of Manila clams since the 1980s. It is thought that infection with the protozoan Perkinsus species has contributed to these decreases. A previous study demonstrated that high infection levels of a pure strain of Perkinsus olseni (ATCC PRA-181) were lethal to hatchery-raised small Manila clams, however, the pathogenicity of wild strain Perkinsus species to wild Manila clam is unclear. To address this, we challenged large (30-40 mm in shell length) and small (3-15 mm in shell length) wild Manila clams with Perkinsus species isolated from naturally infected wild Manila clams. We report high mortalities among the small clams, but not among the large ones. This is the first report to confirm the pathogenicity of wild isolate of Perkinsus species to wild Manila clams. PMID:22687350

  4. Asiatic clam invasion: causes and effects

    SciTech Connect

    Cherry, D.S.; Cairns, J.; Graney, R.L.

    1980-01-01

    The recent introduction and subsequent invasion of the Asiatic clam has offered a new problem of infestation in power plant intake systems that conventional intermittent chlorination procedures may not resolve. These clam invasions adversely affect intake systems and irrigation works by clogging the systems and causing erosion of pipes. Heated power plant discharges were found to be a source of thermal enrichment for the clams. Methods of temperature control followed by chlorination appear to offer short-term solutions; harvesting of the clams for protein and calcium contents present an additional solution.

  5. Multispectral measurements in the surf zone

    NASA Astrophysics Data System (ADS)

    Schoonmaker, Jon S.; Dirbas, Joseph; Gilbert, Gary

    2004-09-01

    Over the past year an index has been defined which quantifies the surf zone with respect to an electro-optical (EO) system"s ability to find targets. The purpose of this index is to both normalize the EO Mine Counter Measure (MCM) systems performance expectations to the environment in which it is tested and to assess the value of its performance in an operational environment. For example, if a given system has a Probability of Detection (PD) requirement of 90% in a clear water surf zone and is tested in murky waters the surf zone index of the murky water is used to determine what PD is required in the murky water to yield the 90% PD clear water requirement. The surf zone index is defined in this paper and expanded from the deterministic contrast transmittance as reported in earlier papers to a probabilistic approach. Examples of how to measure the index using readily available low cost spectral imagers such as PAR Government Systems Corporation"s Mission Adaptable Narrowband Tunable Imaging Spectrometer (MANTIS) system are given. Finally, the surf zone index usage is discussed and demonstrated.

  6. Depuration and anatomical distribution of domoic acid in the surf clam Mesodesma donacium.

    PubMed

    Álvarez, Gonzalo; Uribe, Eduardo; Regueiro, Jorge; Martin, Helena; Gajardo, Teresa; Jara, Lorena; Blanco, Juan

    2015-08-01

    In northern Chile, domoic acid (DA) has been detected in several bivalve species. In Mesodesma donacium, one of the most important commercial species for local fishermen, no information is available on depuration, or on the anatomical distribution of this toxin and its potential use as a palliative measure to minimize the consequences of ASP outbreaks. Deputation of DA is very fast in M. donacium, and can be adequately described by means of a two-compartment model. The estimated rates for the first and second compartments were 1.27 d(-1) and 0.24 d(-1), respectively, with a transfer rate between compartments of 0.75. Having high depuration rates protects this species from being affected by Pseudo-nitzschia blooms for an extended period of time. Taking this into account, the time in which the bivalves are unsafe for consumers is very short, and therefore the economic losses that could result by the DA outbreaks in local fisheries should be moderate. In relation to anatomical distribution, at least during the uptake phase, the toxin was evenly distributed within the soft tissues, with a total toxin burden corresponding to 27%, 32% and 41% for Digestive Gland (DG), Foot (FT) and Other Body Fractions (OBF), respectively. Since the contribution of each organ to the toxin concentration is a function of both weight contribution and toxin burden, the pattern of toxin distribution showed the following trend: "all other body fractions" (OBF) > Foot (FT) > Digestive Gland (DG). Thus, the highest concentration of DA, with a contribution close to 72%, corresponds to the edible tissues (OBF + FT), while the DG (non-edible tissue) only contributes the remaining 28%. Consequently, in view of the anatomical distribution of domoic acid in M. donacium, the elimination of the digestive gland does not substantially reduce the toxicity of the final product and therefore selective evisceration would not improve their quality for human consumption. PMID:26003793

  7. Surfing Global Change: Negotiating Sustainable Solutions

    ERIC Educational Resources Information Center

    Ahamer, Gilbert

    2006-01-01

    SURFING GLOBAL CHANGE (SGC) serves as a procedural shell for attaining sustainable solutions for any interdisciplinary issue and is intended for use in advanced university courses. The participants' activities evolve through five levels from individual argumentation to molding one's own views for the "common good." The paradigm of "ethics of…

  8. Turbulent viscosity in natural surf zones

    NASA Astrophysics Data System (ADS)

    Grasso, F.; Ruessink, B. G.

    2012-12-01

    Waves breaking in the shallow surf zone near the shoreline inject turbulence into the water column that may reach the bed to suspend sediment. Breaking-wave turbulence in the surf zone is, however, poorly understood, which is one of the reasons why many process-based coastal-evolution models predict coastal change during severe storms inadequately. Here, we use data collected in two natural surf zones to derive a new parameterization for the stability function Cμ that determines the magnitude of the eddy viscosity νt in two-equation turbulent-viscosity models, νt = Cμk2/ε, where k is turbulent kinetic energy and ε is the turbulence dissipation rate. In both data sets, the ratio of turbulence production to dissipation is small (≈0.15), while vertical turbulence diffusion is significant. This differs from assumptions underlying existing Cμ parameterizations, which we show to severely overpredict observed Cμ for most conditions. Additionally, we rewrite our new Cμ parameterization into a formulation that accurately reproduces our Reynolds-stress based estimates of turbulence production. This formulation is linear with strain, consistent with earlier theoritical work for large strain rates. Also, it does not depend on ε and can, therefore, also be applied in one-equation turbulent-viscosity models. We anticipate our work to improve turbulence modeling in natural surf zones and to eventually lead to more reliable predictions of coastal evolution in response to severe storms.

  9. CLaMS: Classifier for Metagenomic Sequences

    Energy Science and Technology Software Center (ESTSC)

    2010-12-01

    CLaMS-"Classifer for Metagenonic Sequences" is a Java application for binning assembled metagenomes wings user-specified training sequence sets and other user-specified initial parameters. Since ClAmS analyzes and matches sequence composition-based genomic signatures, it is much faster than binning tools that rely on alignments to homologs; CLaMS can bin ~20,000 sequences in 3 minutes on a laptop with a 2.4 Ghz. Intel Core 2 Duo processor and 2 GB Ram. CLaMS is meant to be desktop applicationmore » for biologist and can be run on any machine under any operating system on which the Java Runtime Environment is enabled. CLaMS is freely available in both GVI-based and command-line based forms.« less

  10. Multispectral observations of the surf zone

    NASA Astrophysics Data System (ADS)

    Schoonmaker, Jon S.; Dirbas, Joseph; Gilbert, Gary

    2003-09-01

    Airborne multispectral imagery was collected over various targets on the beach and in the water in an attempt to characterize the surf zone environment with respect to electro-optical system capabilities and to assess the utility of very low cost, small multispectral systems in mine counter measures (MCM) and intelligence, surveillance and reconnaissance applications. The data was collected by PAR Government Systems Corporation (PGSC) at the Army Corps of Engineers Field Research Facility at Duck North Carolina and on the beaches of Camp Pendleton Marine Corps Base in Southern California. PGSC flew the first two of its MANTIS (Mission Adaptable Narrowband Tunable Imaging Sensor) systems. Both MANTIS systems were flown in an IR - red - green - blue (700, 600, 550, 480 nm) configuration from altitudes ranging from 200 to 700 meters. Data collected has been lightly analyzed and a surf zone index (SZI) defined and calculated. This index allows mine hunting system performance measurements in the surf zone to be normalized by environmental conditions. The SZI takes into account water clarity, wave energy, and foam persistence.

  11. Dwarf novae

    NASA Technical Reports Server (NTRS)

    Ladous, Constanze

    1993-01-01

    Dwarf novae are defined on grounds of their semi-regular brightness variations of some two to five magnitudes on time scales of typically 10 to 100 days. Historically several different classification schemes have been used. Today, dwarf novae are divided into three sub-classes: the U Geminorum stars, the SU Ursae Majoris stars, and the Z Camelopardalis stars. Outbursts of dwarf novae occur at semi-periodic intervals of time, typically every 10 to 100 days; amplitudes range from typically 2 to 5 mag. Within certain limits values are characteristic for each object. Relations between the outburst amplitude, or the total energy released during outburst, and the recurrence time have been found, as well as relations between the orbital period and the outburst decay time, the absolute magnitude during outburst maximum, and the widths of long and short outbursts, respectively. Some dwarf novae are known to have suspended their normal outburst activity altogether for a while. They later resumed it without having undergone any observable changes. The optical colors of dwarf novae all are quite similar during outburst, considerably bluer than during the quiescent state. During the outburst cycle, characteristic loops in the two color diagram are performed. At a time resolution on the order of minutes, strictly periodic photometric changes due to orbital motion become visible in the light curves of dwarf novae. These are characteristic for each system. Remarkably little is known about orbital variations during the course of an outburst. On time-scales of minutes and seconds, further more or less periodic types of variability are seen in dwarf novae. Appreciable flux is emitted by dwarf novae at all wavelengths from the X-rays to the longest IR wavelengths, and in some cases even in the radio. Most dwarf novae exhibit strong emission line spectra in the optical and UV during quiescence, although some have only very weak emissions in the optical and/or weak absorptions at UV

  12. The Clam Trail: Blending Science Education, Public Art, and Tourism

    ERIC Educational Resources Information Center

    Muscio, Cara; Flimlin, Gef; Bushnell, Rick

    2011-01-01

    The Barnegat Bay Shellfish Restoration's Clam Trail is an award-winning scavenger hunt that combines science education, public art, and tourism. This family adventure has participants seeking out giant painted fiberglass clams, upweller clam nurseries, and points of interest in search of science facts to record on their forms. Upon returning these…

  13. 33 CFR 117.323 - Outer Clam Bay.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Outer Clam Bay. 117.323 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.323 Outer Clam Bay. The drawspan of the Outer Clam Bay Boardwalk Drawbridge shall open on signal if at least 30 minutes advance notice is given....

  14. 33 CFR 117.323 - Outer Clam Bay

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Outer Clam Bay 117.323 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.323 Outer Clam Bay The drawspan of the Outer Clam Bay Boardwalk Drawbridge shall open on signal if at least 30 minutes advance notice is given....

  15. 33 CFR 117.323 - Outer Clam Bay.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Outer Clam Bay. 117.323 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.323 Outer Clam Bay. The drawspan of the Outer Clam Bay Boardwalk Drawbridge shall open on signal if at least 30 minutes advance notice is given....

  16. 33 CFR 117.323 - Outer Clam Bay

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Outer Clam Bay 117.323 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.323 Outer Clam Bay The drawspan of the Outer Clam Bay Boardwalk Drawbridge shall open on signal if at least 30 minutes advance notice is given....

  17. 33 CFR 117.323 - Outer Clam Bay

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Outer Clam Bay 117.323 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.323 Outer Clam Bay The drawspan of the Outer Clam Bay Boardwalk Drawbridge shall open on signal if at least 30 minutes advance notice is given....

  18. User's Manual for Space Debris Surfaces (SD_SURF)

    NASA Technical Reports Server (NTRS)

    Elfer, N. C.

    1996-01-01

    A unique collection of computer codes, Space Debris Surfaces (SD_SURF), have been developed to assist in the design and analysis of space debris protection systems. SD_SURF calculates and summarizes a vehicle's vulnerability to space debris as a function of impact velocity and obliquity. An SD_SURF analysis will show which velocities and obliquities are the most probable to cause a penetration. This determination can help the analyst select a shield design which is best suited to the predominant penetration mechanism. The analysis also indicates the most suitable parameters for development or verification testing. The SD_SURF programs offer the option of either FORTRAN programs and Microsoft EXCEL spreadsheets and macros. The FORTRAN programs work with BUMPERII version 1.2a or 1.3 (Cosmic released). The EXCEL spreadsheets and macros can be used independently or with selected output from the SD_SURF FORTRAN programs.

  19. Allele surfing promotes microbial adaptation from standing variation.

    PubMed

    Gralka, Matti; Stiewe, Fabian; Farrell, Fred; Möbius, Wolfram; Waclaw, Bartlomiej; Hallatschek, Oskar

    2016-08-01

    The coupling of ecology and evolution during range expansions enables mutations to establish at expanding range margins and reach high frequencies. This phenomenon, called allele surfing, is thought to have caused revolutions in the gene pool of many species, most evidently in microbial communities. It has remained unclear, however, under which conditions allele surfing promotes or hinders adaptation. Here, using microbial experiments and simulations, we show that, starting with standing adaptive variation, range expansions generate a larger increase in mean fitness than spatially uniform population expansions. The adaptation gain results from 'soft' selective sweeps emerging from surfing beneficial mutations. The rate of these surfing events is shown to sensitively depend on the strength of genetic drift, which varies among strains and environmental conditions. More generally, allele surfing promotes the rate of adaptation per biomass produced, which could help developing biofilms and other resource-limited populations to cope with environmental challenges. PMID:27307400

  20. Surfing into spirituality and a new, aquatic nature religion.

    PubMed

    Taylor, Bron

    2007-01-01

    "Soul surfers" consider surfing to be a profoundly meaningful practice that brings physical, psychological, and spiritual benefits. They generally agree on where surfing initially developed, that it assumed a religious character, was suppressed for religious reasons, has been undergoing a revival, and enjoins reverence for and protection of nature. This subset of the global surfing community should be understood as a new religious movement-a globalizing, hybridized, and increasingly influential example of what I call aquatic nature religion. For these individuals, surfing is a religious form in which a specific sensual practice constitutes its sacred center, and the corresponding experiences are constructed in a way that leads to a belief in nature as powerful, transformative, healing, and sacred. I advance this argument by analyzing these experiences, as well as the myths, rites, symbols, terminology, technology, material culture, and ethical mores that are found within surfing subcultures. PMID:20681093

  1. Ordering dynamics in collectively swimming Surf Scoters.

    PubMed

    Lukeman, Ryan

    2014-08-21

    One striking feature of collective motion in animal groups is a high degree of alignment among individuals, generating polarized motion. When order is lost, the dynamic process of reorganization, directly resulting from the individual interaction rules, provides significant information about both the nature of the rules, and how these rules affect the functioning of the collective. By analyzing trajectories of collectively swimming Surf Scoters (Melanitta perspicillata) during transitions between order and disorder, I find that individual speed and polarization are positively correlated in time, such that individuals move more slowly in groups exhibiting lower alignment. A previously validated zone-based model framework is used to specify interactions that permit repolarization while maintaining group cohesion and avoiding collisions. Polarization efficiency is optimized under the constraints of cohesion and collision-avoidance for alignment-dominated propulsion (versus autonomous propulsion), and for repulsion an order of magnitude larger than attraction and alignment. The relative strengths of interactions that optimize polarization also quantitatively recover the speed-polarization dependence observed in the data. Parameters determined here through optimizing polarization efficiency are essentially the same as those determined previously from a different approach: a best-fit model for polarized Surf Scoter movement data. The rules governing these flocks are therefore robust, accounting for behavior across a range of order and structure, and also highly responsive to perturbation. Flexibility and efficient repolarization offers an adaptive explanation for why specific interactions in such animal groups are used. PMID:24675619

  2. SURF1 deficiency causes demyelinating Charcot-Marie-Tooth disease

    PubMed Central

    Ghezzi, Daniele; Chassagne, Maïté; Mayençon, Martine; Padet, Sylvie; Melchionda, Laura; Rouvet, Isabelle; Lannes, Béatrice; Bozon, Dominique; Latour, Philippe; Zeviani, Massimo; Mousson de Camaret, Bénédicte

    2013-01-01

    Objective: To investigate whether mutations in the SURF1 gene are a cause of Charcot-Marie-Tooth (CMT) disease. Methods: We describe 2 patients from a consanguineous family with demyelinating autosomal recessive CMT disease (CMT4) associated with the homozygous splice site mutation c.107-2A>G in the SURF1 gene, encoding an assembly factor of the mitochondrial respiratory chain complex IV. This observation led us to hypothesize that mutations in SURF1 might be an unrecognized cause of CMT4, and we investigated SURF1 in a total of 40 unrelated patients with CMT4 after exclusion of mutations in known CMT4 genes. The functional impact of c.107-2A>G on splicing, amount of SURF1 protein, and on complex IV activity and assembly was analyzed. Results: Another patient with CMT4 was found to harbor 2 additional SURF1 mutations. All 3 patients with SURF1-associated CMT4 presented with severe childhood-onset neuropathy, motor nerve conduction velocities <25 m/s, and lactic acidosis. Two patients had brain MRI abnormalities, including putaminal and periaqueductal lesions, and developed cerebellar ataxia years after polyneuropathy. The c.107-2A>G mutation produced no normally spliced transcript, leading to SURF1 absence. However, complex IV remained partially functional in muscle and fibroblasts. Conclusions: We found SURF1 mutations in 5% of families (2/41) presenting with CMT4. SURF1 should be systematically screened in patients with childhood-onset severe demyelinating neuropathy and additional features such as lactic acidosis, brain MRI abnormalities, and cerebellar ataxia developing years after polyneuropathy. PMID:24027061

  3. Foraging behaviors of Surf Scoters and White-Winged Scoters during spawning of Pacific herring

    USGS Publications Warehouse

    Esler, Daniel N.; Boyd, Sean

    2007-01-01

    Winter diets of Surf (Melanitta perspicillata) and White-winged Scoters (M. fusca) are composed primarily of bivalves. During spawning of Pacific herring (Clupea pallasi) in early spring, scoters shift their diets to herring eggs. Using radio-telemetry, we contrasted scoter foraging behaviorsbetween winter and herring spawning periods. Scoters increased their dive durations during herring spawning, likely to maximize the amount of roe consumed per dive; in winter, dives were typically terminated upon clam capture. Scoters spent approximately 50% less time foraging ( $min underwater hr^{-1}$ ) and decreased their dive rate (dives hr -1 ) by 70% when feeding on roe. The observed reduction in time spent foraging was presumably caused by the abundance of herring eggs, and thus a reduction in prey search-time. Scoters were able to meet energetic requirements with reduced effort, despite potentially increased demands related to spring fattening. Less time spentforaging may also allow more time for premigratory courtship behaviors

  4. Women in wetsuits: revolting bodies in lesbian surf culture.

    PubMed

    Roy, Georgina

    2013-01-01

    The article unpicks the notion of lesbian bodies as revolting through an analysis of how "women in wetsuits" are experienced as both disgusting and desirable by lesbian surfers. Based on ethnographic research carried out within British surf culture, I consider how lesbian surfing bodies come to be experienced and embodied as disgusting, desirable, and revolting. Informed by interview data and personal reflections I suggest that the affective power of lesbian desire might offer ways in which to disrupt the cultural processes that shame bodies and in doing so enable surfing bodies to revolt. PMID:23855945

  5. A role for heparan sulfate in viral surfing

    SciTech Connect

    Oh, Myung-Jin; Akhtar, Jihan; Desai, Prashant; Shukla, Deepak

    2010-01-01

    Heparan sulfate (HS) moieties on cell surfaces are known to provide attachment sites for many viruses including herpes simplex virus type-1 (HSV-1). Here, we demonstrate that cells respond to HSV-1 infection by enhancing filopodia formation. Filopodia express HS and are subsequently utilized for the transport of HSV-1 virions to cell bodies in a surfing-like phenomenon, which is facilitated by the underlying actin cytoskeleton and is regulated by transient activation of a small Rho GTPase, Cdc42. We also demonstrate that interaction between a highly conserved herpesvirus envelope glycoprotein B (gB) and HS is required for surfing. A HSV-1 mutant that lacks gB fails to surf and quantum dots conjugated with gB demonstrate surfing-like movements. Our data demonstrates a novel use of a common receptor, HS, which could also be exploited by multiple viruses and quite possibly, many additional ligands for transport along the plasma membrane.

  6. From the Director: Surfing the Web for Health Information

    MedlinePlus

    ... Issue Past Issues From the Director: Surfing the Web for Health Information Past Issues / Spring 2007 Table ... all information on the Internet is reliable. Some Web sites post inaccurate or biased medical information. Others ...

  7. Guide to Healthy Web Surfing: MedlinePlus

    MedlinePlus

    ... medlineplus.gov/healthywebsurfing.html MedlinePlus Guide to Healthy Web Surfing To use the sharing features on this ... the site, use caution. Focus on quality--All Web sites are not created equal Does the site ...

  8. From the Director: Surfing the Web for Health Information

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues From the Director: Surfing the Web for Health Information Past Issues / Spring 2007 ... employees. Photo courtesy of NIH Some tips from the Director of NIH When it comes to gathering ...

  9. Surf Zone Hyperbenthos of Belgian Sandy Beaches: Seasonal Patterns

    NASA Astrophysics Data System (ADS)

    Beyst, B.; Buysse, D.; Dewicke, A.; Mees, J.

    2001-12-01

    Since surf zone hyperbenthos, although highly important in local food webs, has often been neglected and very little information is available, a survey of the Belgian sandy beaches was carried out from May 1996 until July 1997. Monthly samples were taken to give a complete record of hyperbenthic organisms occurring in the surf zone of Belgian sandy beaches and to evaluate the intensity by which this surf zone is used. In total 172 species were recorded. The number of species occurring in the surf zone is comparable to that of adjacent areas. As well as true hyperbenthic species, endobenthic and planktonic organisms were sampled. More than 75% of the average total sample composition consisted of mysids, mainly Mesopodopsis slabberi, Schistomysis spiritus and Schistomysis kervillei (holohyperbenthos). Apart from several resident species, active and passive seasonal migration towards the surf zone by a number of species is suggested. A large number of sporadic species adds to the composition of surf zone hyperbenthos. Within the merohyperbenthos, postlarval decapods and fish were the dominant organisms. During the year three recruitment peaks were observed. Average densities per month exceeded 1500 ind. 100 m -2. Yearly biomass averages ranged from 300 to over 3000 mg ADW 100 m -2. Densities of the common species are slightly higher in the surf zone than in other habitats, emphasising the importance of the area. Besides a possible nursery function, the surf zone may also be used as a transient area between different habitats. Finally, the influence of several abiotic factors on the hyperbenthic assemblages was evaluated. The main structuring variables determining the occurrence of most of the organisms are water temperature and hydrodynamic factors such as wave height and turbidity. The influence of wave height seems to be two-fold: several good swimmers such as mysids and some fish species are suggested to be able to actively avoid severe wave conditions, whereas

  10. Clam-associated vibriosis, USA, 1988–2010

    PubMed Central

    Slayton, R. B.; Newton, A. E.; Depaola, A.; Jones, J. L.; Mahon, B. E.

    2015-01-01

    SUMMARY Infections with Vibrio spp. have frequently been associated with consumption of bivalve molluscs, especially oysters, but illness associated with clams has also been well documented. We describe the 2312 domestically acquired foodborne Vibrio infections reported to the Cholera and Other Vibrio Illness Surveillance system from 1988 to 2010. Clams were associated with at least 4% (93 persons, ‘only clams’) and possibly as many as 24% (556 persons, ‘any clams’) of foodborne cases. Of those who consumed ‘only clams’, 77% of infections were caused by V. parahaemolyticus. Clam-associated illnesses were generally similar to those associated with other seafood consumption. Clams associated with these illnesses were most frequently harvested from the Atlantic coastal states and eaten raw. Our study describes the contribution of clams to the overall burden of foodborne vibriosis and indicates that a comprehensive programme to prevent foodborne vibriosis need to address the risks associated with clams. PMID:23920418

  11. Uniaxial diffusion bonding of CLAM/CLAM steels: Microstructure and mechanical performance

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaosheng; Liu, Yongchang; Yu, Liming; Liu, Chenxi; Sui, Guofa; Yang, Jianguo

    2015-06-01

    By performing a two-step uniaxial diffusion bonding, the reliable joining between CLAM/CLAM steels has been attained. The microstructures at the vicinity of the joint region and in base material were respectively investigated through OM, SEM and TEM. The joint interface was integrated, and no microstructural defects were observed. In the base material, small amount of austenite is retained as thin films between martensite laths, which was suggested to be related to the compressive deformation in diffusion bonding. As a candidate structural material for the first wall in fusion energy systems, the radiation resistance of CLAM steel would be deteriorated by the retained austenite. Tensile and impact tests were carried out to assess the reliability of the joints subjected to post bond heat treatment. All the tensile specimens fractured in the base CLAM steel, meaning the good joining between CLAM steels. However, due to the low impact absorbed energy of the joints, efforts should still be made to optimize the bonding technology and the post bond heat treatment further.

  12. Surf5: A gene in the tightly clustered mouse surfeit locus is highly conserved and transcribed divergently from the rpL7A (Surf3) gene

    SciTech Connect

    Garson, K.; Duhig, T.; Armes, N.; Colombo, P.; Fried, M.

    1995-11-20

    The four previously characterized genes (Surf1 to 4) of the mouse Surfeit locus do not share any sequence homology, and the transcription of each gene alternates with respect to its neighbors. Adjacent Surfeit genes are separated by very small distances, and two of the genes overlap at their 3{prime} ends. In this work we have further defined the Surfeit gene cluster by the isolation of Surf5, a fifth gene of the locus, and determination of its relationship to the other Surfeit genes. Surf5 does not share any sequence homology with the four cloned Surfeit genes. The transcription of Surf5 is divergent with respect to its neighbor the Surf3 gene, and the 5{prime} ends of Surf5 and Surf3 are separated by only 159 bp, suggesting the presence of a second bidirectional promoter in the locus. The 3{prime} end of Surf5 maps only 68 bp away from the processed 3{prime} end of a pseudogene. The human and partial chicken Surf5 coding regions show greater than 95% identity, and a Caenorhabditis elegans homologue shows 38% identity and 56% similarity with the mouse Surf5 amino acid sequence. The 3.5-kb transcript of Surf5 encodes a small hydrophilic protein of 140 amino acid residues, which differs from the ribosomal protein L7a encoded by the Surf3 gene or the integral membrane protein encoded by the Surf4 gene. Subcellular fractionation located the Surf5 protein to the soluble fraction of the cytoplasm. The Surfeit locus appears to represent a novel type of gene cluster in which the genes are unrelated by sequence or function; however, their organization may play a role in their gene expression. 44 refs., 5 figs.

  13. Direct measurements of wind stress over the surf zone

    NASA Astrophysics Data System (ADS)

    Shabani, Behnam; Nielsen, Peter; Baldock, Tom

    2014-05-01

    Field data of the wind stress over surf zone waves are presented from an open ocean beach on the East Australian Coast. Two ultrasonic anemometers were deployed at nominal heights of 5 and 10 m above the water surface in the intertidal and inner surf zones, with concurrent measurements of water levels and offshore wave parameters. Following a rigorous quality control procedure, the wind stress was determined by the eddy correlation technique. A constant stress layer was observed between 5 and 10 m elevation. Considering near-neutral conditions only, the wind drag coefficients were found to systematically change with the wind angle of approach relative to the shoreline and are much smaller for longshore wind than during onshore wind. The concept of an apparent wave steepness changing with wind direction is suggested to explain this behavior. The drag coefficients over the surf zone during onshore wind and near-neutral conditions were determined to be almost twice the values expected at the same wind speed and open ocean conditions. The observed Charnock coefficient was similarly an order of magnitude larger than open ocean values. A wave celerity of the order of that expected in the inner surf zone is required to explain the observed large roughness and drag coefficients using existing wave age-dependent parameterizations. This suggests that the slower wave celerity in the surf zone is an important contributor to the increased wind stress, in addition to the sawtooth wave shape.

  14. Toxicity of fishery chemicals to the asiatic clam, Corbicula manilensis

    USGS Publications Warehouse

    Chandler, Jack H.; Marking, L.L.

    1979-01-01

    The Asiatic clam (Corbicula manilensis), a species introduced into U. S. waters, has spread rapidly, and its ability to survive, reproduce, and spread has caused concern. Aquatic biologists suspect that the clams may crowd out indigenous mollusks, and the animals sometimes plug water intakes and leave shell deposits that interfere with sand and gravel operations. The toxicity of 20 commonly used fishery chemicals to the Asiatic clam was determined to evaluate hazards to a nontarget aquatic invertebrate and to assess the potential of the chemicals for controlling clam populations. Among six piscicides and two lampricides tested, antimycin was most toxic to the clam; the 96-h LC50 was 0.065 mg/L. Among three therapeutants and two disinfectants tested, nifurpirinol was the most toxic; the 96-h LC50 was 7.60 mg/L. All of the compounds were less toxic to the clam than to fish. As a nontarget organism, this clam would be safe in water treated with any of the tested fishery chemicals at recommended use pattern concentrations. None of the chemicals have potential for controlling unwanted populations of these clams.

  15. 77 FR 43236 - Proposed Information Collection; Comment Request; SURF Program Student Applicant Information

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    ... National Institute of Standards and Technology Proposed Information Collection; Comment Request; SURF Program Student Applicant Information AGENCY: National Institute of Standards and Technology (NIST... SURF (Summer Undergraduate Research Fellowship) Program. The information will be provided by...

  16. Naming Disney's Dwarfs.

    ERIC Educational Resources Information Center

    Sidwell, Robert T.

    1980-01-01

    Discusses Disney's version of the folkloric dwarfs in his production of "Snow White" and weighs the Disney rendition of the dwarf figure against the corpus of traits and behaviors pertaining to dwarfs in traditional folklore. Concludes that Disney's dwarfs are "anthropologically true." (HOD)

  17. The Sanford Underground Research Facility at Homestake (SURF)

    SciTech Connect

    Lesko, K. T.

    2015-03-24

    The former Homestake gold mine in Lead, South Dakota is being transformed into a dedicated laboratory to pursue underground research in rare-process physics, as well as offering research opportunities in other disciplines. A key component of the Sanford Underground Research Facility (SURF) is the Davis Campus, which is in operation at the 4850-foot level (4300 m.w.e) and currently hosts three projects: the LUX dark matter experiment, the Majorana Demonstrator neutrinoless double-beta decay experiment and the Berkeley and CUBED low-background counters. Plans for possible future experiments at SURF are well underway and include long baseline neutrino oscillation experiments, future dark matter experiments as well as nuclear astrophysics accelerators. Facility upgrades to accommodate some of these future projects have already started. SURF is a dedicated facility with significant expansion capability. These plans include a Generation-2 Dark Matter experiment and the US flagship neutrino experiment, LBNE.

  18. The Sanford Underground Research Facility at Homestake (SURF)

    DOE PAGESBeta

    Lesko, K. T.

    2015-03-24

    The former Homestake gold mine in Lead, South Dakota is being transformed into a dedicated laboratory to pursue underground research in rare-process physics, as well as offering research opportunities in other disciplines. A key component of the Sanford Underground Research Facility (SURF) is the Davis Campus, which is in operation at the 4850-foot level (4300 m.w.e) and currently hosts three projects: the LUX dark matter experiment, the Majorana Demonstrator neutrinoless double-beta decay experiment and the Berkeley and CUBED low-background counters. Plans for possible future experiments at SURF are well underway and include long baseline neutrino oscillation experiments, future dark mattermore » experiments as well as nuclear astrophysics accelerators. Facility upgrades to accommodate some of these future projects have already started. SURF is a dedicated facility with significant expansion capability. These plans include a Generation-2 Dark Matter experiment and the US flagship neutrino experiment, LBNE.« less

  19. Evaluation of Sift and Surf for Vision Based Localization

    NASA Astrophysics Data System (ADS)

    Qu, Xiaozhi; Soheilian, Bahman; Habets, Emmanuel; Paparoditis, Nicolas

    2016-06-01

    Vision based localization is widely investigated for the autonomous navigation and robotics. One of the basic steps of vision based localization is the extraction of interest points in images that are captured by the embedded camera. In this paper, SIFT and SURF extractors were chosen to evaluate their performance in localization. Four street view image sequences captured by a mobile mapping system, were used for the evaluation and both SIFT and SURF were tested on different image scales. Besides, the impact of the interest point distribution was also studied. We evaluated the performances from for aspects: repeatability, precision, accuracy and runtime. The local bundle adjustment method was applied to refine the pose parameters and the 3D coordinates of tie points. According to the results of our experiments, SIFT was more reliable than SURF. Apart from this, both the accuracy and the efficiency of localization can be improved if the distribution of feature points are well constrained for SIFT.

  20. The Sanford Underground Research Facility at Homestake (SURF)

    NASA Astrophysics Data System (ADS)

    Lesko, K. T.

    The former Homestake gold mine in Lead, South Dakota is being transformed into a dedicated laboratory to pursue underground research in rare-process physics, as well as offering research opportunities in other disciplines. A key component of the Sanford Underground Research Facility (SURF) is the Davis Campus, which is in operation at the 4850-foot level (4300 m.w.e) and currently hosts three projects: the LUX dark matter experiment, the MAJORANA DEMONSTRATOR neutrinoless double-beta decay experiment and the Berkeley and CUBED low-background counters. Plans for possible future experiments at SURF are well underway and include long baseline neutrino oscillation experiments, future dark matter experiments as well as nuclear astrophysics accelerators. Facility upgrades to accommodate some of these future projects have already started. SURF is a dedicated facility with significant expansion capability. These plans include a Generation-2 Dark Matter experiment and the US flagship neutrino experiment, LBNE.

  1. The behaviour of giant clams (Bivalvia: Cardiidae: Tridacninae).

    PubMed

    Soo, Pamela; Todd, Peter A

    2014-01-01

    Giant clams, the largest living bivalves, live in close association with coral reefs throughout the Indo-Pacific. These iconic invertebrates perform numerous important ecological roles as well as serve as flagship species-drawing attention to the ongoing destruction of coral reefs and their associated biodiversity. To date, no review of giant clams has focussed on their behaviour, yet this component of their autecology is critical to their life history and hence conservation. Almost 100 articles published between 1865 and 2014 include behavioural observations, and these have been collated and synthesised into five sections: spawning, locomotion, feeding, anti-predation, and stress responses. Even though the exact cues for spawning in the wild have yet to be elucidated, giant clams appear to display diel and lunar periodicities in reproduction, and for some species, peak breeding seasons have been established. Perhaps surprisingly, giant clams have considerable mobility, ranging from swimming and gliding as larvae to crawling in juveniles and adults. Chemotaxis and geotaxis have been established, but giant clams are not phototactic. At least one species exhibits clumping behaviour, which may enhance physical stabilisation, facilitate reproduction, or provide protection from predators. Giant clams undergo several shifts in their mode of acquiring nutrition; starting with a lecithotrophic and planktotrophic diet as larvae, switching to pedal feeding after metamorphosis followed by the transition to a dual mode of filter feeding and phototrophy once symbiosis with zooxanthellae (Symbiodinium spp.) is established. Because of their shell weight and/or byssal attachment, adult giant clams are unable to escape rapidly from threats using locomotion. Instead, they exhibit a suite of visually mediated anti-predation behaviours that include sudden contraction of the mantle, valve adduction, and squirting of water. Knowledge on the behaviour of giant clams will benefit

  2. Manila clam Venerupis philippinarum as a biomonitor to metal pollution

    NASA Astrophysics Data System (ADS)

    Wu, Huifeng; Ji, Chenglong; Wang, Qing; Liu, Xiaoli; Zhao, Jianmin; Feng, Jianghua

    2013-01-01

    The Manila clam Venerupis philippinarum is a good biomonitor/bioindicator to marine metal pollution and is frequently used in aquatic toxicology. Two dominant pedigrees (white and zebra) of clam are distributed in the Bohai Sea; however, little attention has been paid to potential biological differences between these two pedigrees. In this study, we tested the sensitivity of both pedigrees to marine metal (cadmium and zinc) pollution biomonitoring and marine environmental toxicology. Results demonstrate significant biological differences in gills of white and zebra clams based on metabolic profiles and antioxidant enzyme activities. In addition, we found that hypotaurine, malonate and homarine were relatively high in white clam gills, while alanine, arginine, glutamate, succinate, 4-aminobutyrate, taurine and betaine were high in zebra clam gills. Zebra clam gills were also more sensitive to a mixture of Cd and Zn, as shown by antioxidant enzyme activities and metabolic profiles, but white clam gills could accumulate more Zn. Therefore, we suggest that the white pedigree can be used as a biomonitor to marine Zn pollution, whereas the zebra pedigree can be used for toxicology studies on Cd and Zn mixed pollution.

  3. "Surfing Global Change": How Didactic Visions Can Be Implemented

    ERIC Educational Resources Information Center

    Ahamer, Gilbert

    2005-01-01

    Purpose: Aims to examine a negotiation-oriented and partly web-based game "Surfing Global Change" (SGC) invented by the author based on didactics of self-managed learning and successfully implemented in WebCT. Design/methodology/approach: Along three historic generations of web-based teaching (WBT), the key functionalities of any platform…

  4. Safety Strategies While Surfing Online in the Classroom.

    ERIC Educational Resources Information Center

    Demirbilek, Muhammet; Cilesiz, Sebnem; Tozoglu, Dogan

    The Internet has become an indispensable medium of the 21st century. Millions of people are using the Internet for exchanging information, surfing for information on virtually any topic, communicating all over the world, participating in discussion groups, shopping, traveling, and many other online activities. The World Wide Web is constantly…

  5. The Evolution of Technology: A Decade of Surfing the Net

    ERIC Educational Resources Information Center

    Berger, Sandra

    2005-01-01

    The world was a different place when "Understanding Our Gifted" introduced "Surfing the Net" in 1994 as a regular feature. Since then, technology and the Internet have become part of people's culture, permeating almost every aspect of their lives. The Internet has greatly changed the way they conduct business and communicate with friends, it helps…

  6. Internet Surfing for Kindergarten Children: A Feasibility Study

    ERIC Educational Resources Information Center

    Loo, Alfred

    2012-01-01

    The Internet is an effective learning tool for gifted children because it allows them to independently select the areas in which they have talent. The Internet also enables children to discover and maximize their potential. However, younger children might not have a large enough vocabulary to surf the Internet, even if they are gifted. For…

  7. Women's Recreational Surfing: A Patronising Experience

    ERIC Educational Resources Information Center

    Olive, Rebecca; McCuaig, Louise; Phillips, Murray G.

    2015-01-01

    Research analysing the operation of power within sport and physical activity has exposed the marginalisation and exclusion of women's sport in explicit and institutionalised ways. However, for women in recreational and alternative physical activities like surfing, sporting experiences lie outside institutionalised structures, thus requiring…

  8. Collaboration on ICT in Dutch Higher Education: The SURF Approach

    ERIC Educational Resources Information Center

    Boezerooy, Petra; Cordewener, Bas; Liebrand, Wim

    2007-01-01

    In "Thinking Ahead: A Vision of the Role of ICT in Education and Research in the Future, 2007-2010," the higher education institutions in the Netherlands agreed on future strategy. Under the direction of SURF, the Dutch national organization, a collaborative strategy for the application of information and communications technology (ICT) was…

  9. Searching versus surfing: how different ways of acquiring content online affect cognitive processing.

    PubMed

    Wise, Kevin; Kim, Hyo Jung

    2008-06-01

    An experiment tested whether people orient to and encode pictures selected from a Web site differently, depending on whether the pictures were selected by searching or surfing. Participants in the search condition spent more time selecting pictures than the participants in the surf condition spent. The pictures chosen in the search condition elicited cardiac orienting, while pictures chosen in the surf condition did not. Participants recognized pictures acquired by searching more accurately than they recognized those acquired by surfing, indicating that searching led to better encoding than surfing. PMID:18537509

  10. Data on cytochrome c oxidase assembly in mice and human fibroblasts or tissues induced by SURF1 defect.

    PubMed

    Kovářová, Nikola; Pecina, Petr; Nůsková, Hana; Vrbacký, Marek; Zeviani, Massimo; Mráček, Tomáš; Viscomi, Carlo; Houštěk, Josef

    2016-06-01

    This paper describes data related to a research article entitled "Tissue- and species-specific differences in cytochrome c oxidase assembly induced by SURF1 defects" [1]. This paper includes data of the quantitative analysis of individual forms of respiratory chain complexes I, III and IV present in SURF1 knockout (SURF1 (-/-) ) and control (SURF1 (+/+) ) mouse fibroblasts and tissues and in fibroblasts of human control and patients with SURF1 gene mutation. Also it includes data demonstrating response of complex IV, cytochrome c oxidase (COX), to reversible inhibition of mitochondrial translation in SURF1 (-/-) mouse and SURF1 patient fibroblast cell lines. PMID:27408912

  11. Clam predator protection is effective and necessary for food production.

    PubMed

    Munroe, Daphne; Kraeuter, John; Beal, Brian; Chew, Ken; Luckenbach, Mark; Peterson, Charles P

    2015-11-15

    Shellfish aquaculture is a widely practiced way of producing food for human consumption in coastal areas. When farming intertidal clams, farmers commonly protect young seedling clams from predatory losses by covering farmed plots with netting or screening. Recent discussion of the effectiveness of protective nets or screens and their environmental effects has raised questions concerning the utility of the practice. We provide data based on a review of more than 35 peer-reviewed articles, as well as our own research that demonstrates the efficacy of predator protection for clam farms in various habitats around the world. In addition, we evaluate the effects of screening on temperature, and comment on ancient practices of clam gardening as conducted in the Pacific Northwest. PMID:26433775

  12. Collective bubble oscillations as a component of surf infrasound.

    PubMed

    Park, Joseph; Garcés, Milton; Fee, David; Pawlak, Geno

    2008-05-01

    Plunging surf is a known generator of infrasound, though the mechanisms have not been clearly identified. A model based on collective bubble oscillations created by demise of the initially entrained air pocket is examined. Computed spectra are compared to infrasound data from the island of Kauai during periods of medium, large, and extreme surf. Model results suggest that bubble oscillations generated by plunging waves are plausible generators of infrasound, and that dynamic bubble plume evolution on a temporal scale comparable to the breaking wave period may contribute to the broad spectral lobe of dominant infrasonic energy observed in measured data. Application of an inverse model has potential to characterize breaking wave size distributions, energy, and temporal changes in seafloor morphology based on remotely sensed infrasound. PMID:18529169

  13. Monitoring system specifications: retrieval of surf from a salt repository

    SciTech Connect

    Not Available

    1980-01-01

    The task of developing specifications for a reference monitoring system determined by repository environmental conditions, retrieval operations, and federal regulatory criteria is discussed. The monitoring system specified in this report is capable of measuring (1) package position and orientation, (2) vault deformation, (3) brine accumulation, (4) spent fuel dissolution, (5) temperature, (6) nuclear radiation, and (7) package condition with sufficient accuracy to provide data input to a general risk assessment model. In order to define a monitoring system which can provide probabilistic data on radiological risk to operating personnel and the general public for a salt mine repository, the following information is required: (1) a complete design of the salt SURF repository including inventory, density and waste package design details; (2) probalistic failure rate data on containment integrity of the SURF waste package; (3) probabilistic failure rate data on the monitoring system components (i.e., monitoring procedure, instrumentation, data acquisition, data processing and data interpretation).

  14. Region Duplication Forgery Detection Technique Based on SURF and HAC

    PubMed Central

    Mishra, Parul; Sharma, Sanjeev; Patel, Ravindra

    2013-01-01

    Region duplication forgery detection is a special type of forgery detection approach and widely used research topic under digital image forensics. In copy move forgery, a specific area is copied and then pasted into any other region of the image. Due to the availability of sophisticated image processing tools, it becomes very hard to detect forgery with naked eyes. From the forged region of an image no visual clues are often detected. For making the tampering more robust, various transformations like scaling, rotation, illumination changes, JPEG compression, noise addition, gamma correction, and blurring are applied. So there is a need for a method which performs efficiently in the presence of all such attacks. This paper presents a detection method based on speeded up robust features (SURF) and hierarchical agglomerative clustering (HAC). SURF detects the keypoints and their corresponding features. From these sets of keypoints, grouping is performed on the matched keypoints by HAC that shows copied and pasted regions. PMID:24311972

  15. Distinguishing high surf from volcanic long-period earthquakes

    NASA Astrophysics Data System (ADS)

    Lyons, John J.; Haney, Matthew M.; Fee, David; Paskievitch, John F.

    2014-02-01

    Repeating long-period (LP) earthquakes are observed at active volcanoes worldwide and are typically attributed to unsteady pressure fluctuations associated with fluid migration through the volcanic plumbing system. Nonvolcanic sources of LP signals include ice movement and glacial outburst floods, and the waveform characteristics and frequency content of these events often make them difficult to distinguish from volcanic LP events. We analyze seismic and infrasound data from an LP swarm recorded at Pagan volcano on 12-14 October 2013 and compare the results to ocean wave data from a nearby buoy. We demonstrate that although the events show strong similarity to volcanic LP signals, the events are not volcanic but due to intense surf generated by a passing typhoon. Seismo-acoustic methods allow for rapid distinction of volcanic LP signals from those generated by large surf and other sources, a critical task for volcano monitoring.

  16. Ultraviolet degradation study of photomultiplier tubes at SURF III

    NASA Astrophysics Data System (ADS)

    Hum, Lindsay; Shaw, Ping-Shine; Li, Zhigang; Lykke, Keith R.; Bishop, Michael L.

    2009-05-01

    Photomultiplier tubes (PMTs) are used in biological detection systems in order to detect the presence of biological warfare agents. To ensure proper operation of these biological detection systems, the performance of PMTs must be characterized in terms of their responsivity and long-term stability. We report a technique for PMT calibration at the Synchrotron Ultraviolet Radiation Facility (SURF III) at the National Institute of Standards and Technology (NIST). SURF III provides synchrotron radiation with a smooth and continuous spectrum covering the entire UV range for accurate PMT measurements. By taking advantage of the ten decade variability in the flux of the synchrotron radiation, we studied properties of commercial PMTs such as the linearity, spatial uniformity, and spectral responsivity. We demonstrate the degradation of PMTs by comparing new PMTs with PMTs that were used and operated in a biological detection system for a long period of time. The observed degradation is discussed.

  17. 50 CFR 648.1 - Purpose and scope.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... fishery (Scallop FMP); the Atlantic surf clam and ocean quahog fisheries (Atlantic Surf Clam and Ocean..., in § 648.1, paragraph (a) was amended by removing the words “surf clam” and “Surf Clam” and...

  18. SURF IA Conflict Detection and Resolution Algorithm Evaluation

    NASA Technical Reports Server (NTRS)

    Jones, Denise R.; Chartrand, Ryan C.; Wilson, Sara R.; Commo, Sean A.; Barker, Glover D.

    2012-01-01

    The Enhanced Traffic Situational Awareness on the Airport Surface with Indications and Alerts (SURF IA) algorithm was evaluated in a fast-time batch simulation study at the National Aeronautics and Space Administration (NASA) Langley Research Center. SURF IA is designed to increase flight crew situation awareness of the runway environment and facilitate an appropriate and timely response to potential conflict situations. The purpose of the study was to evaluate the performance of the SURF IA algorithm under various runway scenarios, multiple levels of conflict detection and resolution (CD&R) system equipage, and various levels of horizontal position accuracy. This paper gives an overview of the SURF IA concept, simulation study, and results. Runway incursions are a serious aviation safety hazard. As such, the FAA is committed to reducing the severity, number, and rate of runway incursions by implementing a combination of guidance, education, outreach, training, technology, infrastructure, and risk identification and mitigation initiatives [1]. Progress has been made in reducing the number of serious incursions - from a high of 67 in Fiscal Year (FY) 2000 to 6 in FY2010. However, the rate of all incursions has risen steadily over recent years - from a rate of 12.3 incursions per million operations in FY2005 to a rate of 18.9 incursions per million operations in FY2010 [1, 2]. The National Transportation Safety Board (NTSB) also considers runway incursions to be a serious aviation safety hazard, listing runway incursion prevention as one of their most wanted transportation safety improvements [3]. The NTSB recommends that immediate warning of probable collisions/incursions be given directly to flight crews in the cockpit [4].

  19. Fatal accidents due to train surfing in Berlin.

    PubMed

    Strauch, H; Wirth, I; Geserick, G

    1998-06-01

    This study was undertaken for the purpose of analysing under the aspect of legal medicine, fatal accidents due to train surfing in the local transport system of Berlin (S-Bahn and underground). The period of investigation was from 1989 through 1995, with 41 train surfing accidents, among them 18 with fatal outcome. Evaluation included those 14 deaths which were forensically autopsied. It was based on autopsy records of Berlin-based university institutes (Humboldt University and Free University) as well as the Brandenburg State Institute of Legal Medicine. Also used were data obtained from the Berlin Transport Police Record. The casualties were aged between 13 and 25 years, most of them between 16 and 20. The male-female gender ratio was 13:1. Accidents occurred above all in the warmer season of the year, most of them between 20:00 h and midnight. More than 50% of all cases were affected by alcohol, but centrally acting medicaments or other addictive drugs were not noticed at all. Most of the fatal accidents occurred to users of the Berlin S-Bahn network. Older train models were the preferred surfing objects due to their structural peculiarities. Collision with close-to-track obstacles and slipping from the train proved to be the major sources of danger. An analysis of injuries revealed polytraumatisation but for one exception, with craniocerebral injuries being the most common and severest events. The longest survival time amounted to 24 h. As the psychosocial causes of high-risk behaviour of adolescents will hardly be controllable, withdrawal of technical, that is structural design possibilities appears to be the most important approach to prevention of accidents in the future. This demand is met by the new series of the Berlin S-Bahn. The model of the old series, suitable for surfing, still accounts for about 10% of the rolling stock and is to be decommissioned in 1998. PMID:9670490

  20. Fluid Impact as a Source Mechanism for Surf Infrasound

    NASA Astrophysics Data System (ADS)

    Fee, D.; Garces, M.; McNamara, S.; Aucan, J.; Merrifield, M.

    2006-12-01

    The ability to provide infrasonic estimates of breaking ocean wave height and period in shallow reefs, steep rocky coastlines, and sand beaches has been demonstrated in previous work. Yet defining the source process and isolating the source pressure function remained elusive because of ambiguity introduced by complex coastlines and multiple breaker zones. Due to the steep bathymetry and its proximity to land, the Temae reef in the northeast coast of Moorea island, French Polynesia, provided a well constrained experimental environment where individual breaking waves could be identified and recorded. Synchronous wave height, infrasonic, seismic, and visual recordings of individual waves breaking against the shallow reef ledge were made and correlated. We characterize a possible fluid impact source mechanism for surf infrasound, demonstrate the capability to acoustically track alongshore traveling (peeling) plunging waves, and confirm a relationship between ocean wave height and infrasonic amplitude. Depending on the swell and coastal conditions, estimates of ocean wave period are also possible. We also present preliminary results on near-real-time remote infrasonic monitoring of the surf zone on the North Shore of Oahu, Hawaii, during the 2006-07 Winter high surf season.

  1. A real-time FPGA-based architecture for OpenSURF

    NASA Astrophysics Data System (ADS)

    Chen, Chaoxiu; Yong, Huang; Zhong, Sheng; Yan, Luxin

    2015-12-01

    This paper proposes a low-cost FPGA architecture of Speed-Up Robust Features (SURF) algorithm based on OpenSURF. It optimizes the computing architecture for the steps of feature detection and feature description involved in SURF to reduce the resource utilization and improve processing speed. As a result, this architecture can detect feature and extract descriptor from video streams of 800x600 resolutions at 60 frames per second (60fps). Extensive experiments have demonstrated its efficiency and effectiveness.

  2. SURF_ER—surface electron spin resonance (ESR) of the surface domain of large objects

    NASA Astrophysics Data System (ADS)

    Herrling, Th.; Rehberg, J.; Jung, K.; Groth, N.

    2002-04-01

    SURF_ER is a method for spectral and spatial electron spin resonance measurements on the surface of large objects which extension is only restricted by the width of the pole gap of the magnet and the homogeneity of the magnetic field and not by the cavity dimensions. The application of several techniques like SURF_ER for spectroscopic measurements, SURF_ERM for spatial scanning and SURF_ERI for spatial measurements of the depth of the surface region are discussed and represented for the skin of a human being as an example.

  3. Ancient Clam Gardens Increased Shellfish Production: Adaptive Strategies from the Past Can Inform Food Security Today

    PubMed Central

    Groesbeck, Amy S.; Rowell, Kirsten; Lepofsky, Dana; Salomon, Anne K.

    2014-01-01

    Maintaining food production while sustaining productive ecosystems is among the central challenges of our time, yet, it has been for millennia. Ancient clam gardens, intertidal rock-walled terraces constructed by humans during the late Holocene, are thought to have improved the growing conditions for clams. We tested this hypothesis by comparing the beach slope, intertidal height, and biomass and density of bivalves at replicate clam garden and non-walled clam beaches in British Columbia, Canada. We also quantified the variation in growth and survival rates of littleneck clams (Leukoma staminea) we experimentally transplanted across these two beach types. We found that clam gardens had significantly shallower slopes than non-walled beaches and greater densities of L. staminea and Saxidomus giganteus, particularly at smaller size classes. Overall, clam gardens contained 4 times as many butter clams and over twice as many littleneck clams relative to non-walled beaches. As predicted, this relationship varied as a function of intertidal height, whereby clam density and biomass tended to be greater in clam gardens compared to non-walled beaches at relatively higher intertidal heights. Transplanted juvenile L. staminea grew 1.7 times faster and smaller size classes were more likely to survive in clam gardens than non-walled beaches, specifically at the top and bottom of beaches. Consequently, we provide strong evidence that ancient clam gardens likely increased clam productivity by altering the slope of soft-sediment beaches, expanding optimal intertidal clam habitat, thereby enhancing growing conditions for clams. These results reveal how ancient shellfish aquaculture practices may have supported food security strategies in the past and provide insight into tools for the conservation, management, and governance of intertidal seascapes today. PMID:24618748

  4. Deployed bivalves (oysters and clams) as indicators of estuarine condition

    SciTech Connect

    Ringwood, A.H.; Holland, A.F.; Keppler, C.; Wert, M.; Hyland, J.

    1995-12-31

    Hatchery-reared bivalves, oysters (Crassostrea virginica) and clams (Mercenaria mercenaria), were deployed simultaneously at reference and degraded sites in SC estuaries for approximately 1 month. Juvenile bivalves with endogenously high growth rates were used because effects on growth can be detected in a short time frame. The effects on growth and bioaccumulation of metal contaminants, as well as two biochemical indices (expression of metallothioneins, MT, and multi-xenobiotic transporting proteins, {at}R) were evaluated. Metal concentrations of sediments were also measured. Adverse effects on growth of both species were observed at degraded sites. However, oysters tended to grow more rapidly than clams, and adverse effects on oysters were more pronounced than in clams. Many of the sediments were characterized by elevated concentrations of multiple metals (Cu, Pb, Cr, etc.). However, increases in metal concentrations of oyster tissues were observed primarily with Cu, suggesting that many of the other metals had low bioavailability. There was little evidence of bioconcentration of any metals in clams. There was a significant correlation between sediment Cu and Cu in oyster tissues, but not in clams. Alterations in MT and MXR expression were also observed in oysters deployed at degraded sites. These studies suggest that oysters may be better in-situ indicators of habitat condition because they have more rapid growth rates and greater bioaccumulation potentials.

  5. An efficient method of noroviruses recovery from oysters and clams

    NASA Astrophysics Data System (ADS)

    Zhou, Deqing; Ma, Liping; Zhao, Feng; Yao, Lin; Su, Laijin; Li, Xinguang

    2013-03-01

    Noroviruses (NoVs) are widespread causes of nonbacterial gastroenteritis. Outbreaks of NoVs caused diseases are commonly ascribed to the consumption of contaminated shellfish. The concentration and RNA extraction of NoVs are crucial steps of detecting NoVs in shellfish. This study aimed to select a simple, rapid and highly efficient recovery method of NoVs detection with real-time RT-PCR. Four methods of recovering GI.3 and GII.4 NoVs from spiked digestive tissues of oysters and clams, respectively, were compared, of them, the method involving proteinase K and PEG 8000 was found the most efficient. With this method, 9.3% and 13.1% of GI.3 and GII.4 NoVs were recovered from oysters and 9.6% and 12.3% of GI.3 and GII.4 NoVs were recovered from clams, respectively. This method was further used to detect NoVs in 84 oysters ( Crassostrea gigas) and 86 clams ( Ruditapes philippinarum) collected from 10 coastal cities in China from Jan. 2011 to Feb. 2012. The NoVs isolation rates were 10.47% of clams (9/86) and 7.14% of oysters (6/84). All the detected NoVs belonged to genotype GII. The NoVs recovery method selected is efficient for NoVs detection in oysters and clams.

  6. Toxicity of a traditional molluscicide to asian clam veligers

    USGS Publications Warehouse

    Layhee, Megan J.; Miho Yoshioka; Miho Yoshioka; Bahram Farokhkish; Bahram Farokhkish; Gross, Jackson A.; Sepulveda, Adam J.

    2014-01-01

    Aquaculture and hatchery industries are in need of effective control methods to reduce the risk of spreading aquatic invasive species, such as the Asian clam Corbicula fluminea, through aquaculture and hatchery activities. The planktonic nature of Asian clam veligers enables this life stage to enter water-based infrastructure undetected, including hatchery trucks used to stock fish. Once in hatchery trucks, veligers can disperse overland and establish in previously uninvaded habitats. As a result, there is a need to develop techniques that result in veliger mortality but do not harm fish. In September 2012, we conducted laboratory trials to determine if a molluscicide (750 mg/L potassium chloride and 25 mg/L formalin) commonly used to kill zebra mussel (Dreissena polymorpha) veligers in hatchery trucks can also effectively kill Asian clam veligers. We exposed Asian clam veligers to this molluscicide for 1, 3, and 5 h in each of two water types: deionized water and filtered lake water. We found ,20% mortality at the 1-h exposure period and 100% mortality at both the 3-h and 5-h exposure periods, regardless of water type. This laboratory study represents an important step toward reducing the spread of Asian clams by aquaculture facilities.

  7. 40 CFR 408.240 - Applicability; description of the mechanized clam processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... mechanized clam processing subcategory. 408.240 Section 408.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Mechanized Clam Processing Subcategory § 408.240 Applicability; description of the mechanized clam processing subcategory. The provisions of this subpart are applicable to discharges...

  8. 40 CFR 408.240 - Applicability; description of the mechanized clam processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... mechanized clam processing subcategory. 408.240 Section 408.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Mechanized Clam Processing Subcategory § 408.240 Applicability; description of the mechanized clam processing subcategory. The provisions of this subpart are applicable to discharges...

  9. 40 CFR 408.230 - Applicability; description of the hand-shucked clam processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-shucked clam processing subcategory. 408.230 Section 408.230 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hand-Shucked Clam Processing Subcategory § 408.230 Applicability; description of the hand-shucked clam processing subcategory. The provisions of this subpart are applicable to discharges...

  10. 40 CFR 408.230 - Applicability; description of the hand-shucked clam processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-shucked clam processing subcategory. 408.230 Section 408.230 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hand-Shucked Clam Processing Subcategory § 408.230 Applicability; description of the hand-shucked clam processing subcategory. The provisions of this subpart are applicable to discharges...

  11. 40 CFR 408.240 - Applicability; description of the mechanized clam processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... mechanized clam processing subcategory. 408.240 Section 408.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Mechanized Clam Processing Subcategory § 408.240 Applicability; description of the mechanized clam processing subcategory. The provisions of this subpart are applicable to discharges...

  12. 40 CFR 408.230 - Applicability; description of the hand-shucked clam processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-shucked clam processing subcategory. 408.230 Section 408.230 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hand-Shucked Clam Processing Subcategory § 408.230 Applicability; description of the hand-shucked clam processing subcategory. The provisions of this subpart are applicable to discharges...

  13. 40 CFR 408.240 - Applicability; description of the mechanized clam processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... mechanized clam processing subcategory. 408.240 Section 408.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Mechanized Clam Processing Subcategory § 408.240 Applicability; description of the mechanized clam processing subcategory. The provisions of this subpart are applicable to discharges...

  14. 40 CFR 408.230 - Applicability; description of the hand-shucked clam processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-shucked clam processing subcategory. 408.230 Section 408.230 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hand-Shucked Clam Processing Subcategory § 408.230 Applicability; description of the hand-shucked clam processing subcategory. The provisions of this subpart are applicable to discharges...

  15. 40 CFR 408.230 - Applicability; description of the hand-shucked clam processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-shucked clam processing subcategory. 408.230 Section 408.230 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hand-Shucked Clam Processing Subcategory § 408.230 Applicability; description of the hand-shucked clam processing subcategory. The provisions of this subpart are applicable to discharges...

  16. 40 CFR 408.240 - Applicability; description of the mechanized clam processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... mechanized clam processing subcategory. 408.240 Section 408.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Mechanized Clam Processing Subcategory § 408.240 Applicability; description of the mechanized clam processing subcategory. The provisions of this subpart are applicable to discharges...

  17. Tissue- and species-specific differences in cytochrome c oxidase assembly induced by SURF1 defects

    PubMed Central

    Kovářová, Nikola; Pecina, Petr; Nůsková, Hana; Vrbacký, Marek; Zeviani, Massimo; Mráček, Tomáš; Viscomi, Carlo; Houštěk, Josef

    2016-01-01

    Mitochondrial protein SURF1 is a specific assembly factor of cytochrome c oxidase (COX), but its function is poorly understood. SURF1 gene mutations cause a severe COX deficiency manifesting as the Leigh syndrome in humans, whereas in mice SURF1−/− knockout leads only to a mild COX defect. We used SURF1−/− mouse model for detailed analysis of disturbed COX assembly and COX ability to incorporate into respiratory supercomplexes (SCs) in different tissues and fibroblasts. Furthermore, we compared fibroblasts from SURF1−/− mouse and SURF1 patients to reveal interspecies differences in kinetics of COX biogenesis using 2D electrophoresis, immunodetection, arrest of mitochondrial proteosynthesis and pulse-chase metabolic labeling. The crucial differences observed are an accumulation of abundant COX1 assembly intermediates, low content of COX monomer and preferential recruitment of COX into I–III2–IVn SCs in SURF1 patient fibroblasts, whereas SURF1−/− mouse fibroblasts were characterized by low content of COX1 assembly intermediates and milder decrease in COX monomer, which appeared more stable. This pattern was even less pronounced in SURF1−/− mouse liver and brain. Both the control and SURF1−/− mice revealed only negligible formation of the I–III2–IVn SCs and marked tissue differences in the contents of COX dimer and III2–IV SCs, also less noticeable in liver and brain than in heart and muscle. Our studies support the view that COX assembly is much more dependent on SURF1 in humans than in mice. We also demonstrate markedly lower ability of mouse COX to form I–III2–IVn supercomplexes, pointing to tissue-specific and species-specific differences in COX biogenesis. PMID:26804654

  18. Tissue- and species-specific differences in cytochrome c oxidase assembly induced by SURF1 defects.

    PubMed

    Kovářová, Nikola; Pecina, Petr; Nůsková, Hana; Vrbacký, Marek; Zeviani, Massimo; Mráček, Tomáš; Viscomi, Carlo; Houštěk, Josef

    2016-04-01

    Mitochondrial protein SURF1 is a specific assembly factor of cytochrome c oxidase (COX), but its function is poorly understood. SURF1 gene mutations cause a severe COX deficiency manifesting as the Leigh syndrome in humans, whereas in mice SURF1(-/-) knockout leads only to a mild COX defect. We used SURF1(-/-) mouse model for detailed analysis of disturbed COX assembly and COX ability to incorporate into respiratory supercomplexes (SCs) in different tissues and fibroblasts. Furthermore, we compared fibroblasts from SURF1(-/-) mouse and SURF1 patients to reveal interspecies differences in kinetics of COX biogenesis using 2D electrophoresis, immunodetection, arrest of mitochondrial proteosynthesis and pulse-chase metabolic labeling. The crucial differences observed are an accumulation of abundant COX1 assembly intermediates, low content of COX monomer and preferential recruitment of COX into I-III2-IVn SCs in SURF1 patient fibroblasts, whereas SURF1(-/-) mouse fibroblasts were characterized by low content of COX1 assembly intermediates and milder decrease in COX monomer, which appeared more stable. This pattern was even less pronounced in SURF1(-/-) mouse liver and brain. Both the control and SURF1(-/-) mice revealed only negligible formation of the I-III2-IVn SCs and marked tissue differences in the contents of COX dimer and III2-IV SCs, also less noticeable in liver and brain than in heart and muscle. Our studies support the view that COX assembly is much more dependent on SURF1 in humans than in mice. We also demonstrate markedly lower ability of mouse COX to form I-III2-IVn supercomplexes, pointing to tissue-specific and species-specific differences in COX biogenesis. PMID:26804654

  19. Liquid-bubble Interaction under Surf Zone Breaking Waves

    NASA Astrophysics Data System (ADS)

    Derakhti, M.; Kirby, J. T., Jr.

    2014-12-01

    Liquid-bubble interaction, especially in complex two-phase bubbly flow under breaking waves, is still poorly understood. Derakhti and Kirby (2014a,b) have recently studied bubble entrainment and turbulence modulation by dispersed bubbles under isolated unsteady breaking waves along with extensive model verifications and convergence tests. In this presentation, we continue this examination with attention turned to the simulation of periodic surf zone breaking waves. In addition, the relative importance of preferential accumulation of dispersed bubbles in coherent vortex cores is investigated. Heavier-than-liquid particles, i.e. sediment, tend to accumulate in regions of high strain rate and avoid regions of intense vorticity. In contrast, lighter-than-liquid particles such as bubbles tend to congregate in vortical regions. We perform a three dimensional (3D) large-eddy simulation (LES) using a Navier-Stokes solver extended to incorporate entrained bubble populations, using an Eulerian-Eulerian formulation for the polydisperse bubble phase. The volume of fluid (VOF) method is used for free surface tracking. The model accounts for momentum exchange between dispersed bubbles and liquid phase as well as bubble-induced dissipation. We investigate the formation and evolution of breaking-induced turbulent coherent structures (BTCS) under both plunging and spilling periodic breaking waves as well as BTCS's role on the intermittent 3D distributions of bubble void fraction in the surf zone. We particularly examine the correlation between bubble void fractions and Q-criterion values to quantify this interaction. Also, the vertical transport of dispersed bubbles by downburst type coherent structures in the transition region is compared to that by obliquely descending eddies. All the results are summarized at different zones from outer to inner surf zone.

  20. Correlation between perkinsosis and growth in clams Ruditapes spp.

    PubMed

    Dang, Cécile; de Montaudouin, Xavier; Binias, Cindy; Salvo, Flora; Caill-Milly, Nathalie; Bald, Juan; Soudant, Philippe

    2013-11-01

    Perkinsosis is one of the most widespread diseases affecting commercially important species of molluscs globally. We examined the impact of Perkinsus spp. on shell growth at the individual scale in 2 clam species: Ruditapes decussatus from Mundaka Estuary (Spain) and R. philippinarum from Arcachon Bay (France). At Arcachon, 2 contrasting sites in terms of environment and Perkinsus olseni presence were chosen: Arguin (disease-free) and Ile aux Oiseaux (infected site). We monitored the dynamics of perkinsosis over the course of the experiment at Mundaka and Ile aux Oiseaux. Prevalences were high (>70%), and intensities were around 105 cells g-1 wet gills at Ile aux Oiseaux, and 106 cells g-1 at Mundaka. No significant differences in prevalence or intensity were observed over time. A 2 yr field growth experiment of tagged-recaptured clams was performed to determine individual clam growth rate, condition index (CI), and Perkinsus spp. infection intensity. Clams were collected at Ile aux Oiseaux and transplanted to Arguin. The growth rate was always significantly and negatively correlated with Perkinsus spp. infection, and positively correlated with CI. CI and Perkinsus spp. infection explained 19% and 7% of the variability of the growth rate at Mundaka and Ile aux Oiseaux, respectively. In experimental clams at Arguin, P. olseni infection explained 26% of the variability of the growth rate at the lower tidal level. Our results suggest that at a concentration of between 105 and 106 cells g-1, perkinsosis affects the physiological functions of the clams, highlighted by its impact on the growth rate. PMID:24192002

  1. Cultural boundary surfing in mental health nursing: a creative narration.

    PubMed

    Kidd, Jacquie

    2010-01-01

    In the mental health context, nurses navigate multifaceted boundaries every day in an effort to develop and maintain the therapeutic relationship; an endeavour that is breathtaking in its complexity. In this paper, I adopt an unconventional form of writing to explore the individual nature of cultural boundaries, and uncover hidden messages that impact on our efforts to build connections across cultures and ethnicities in mental health settings. Presented as a play, the conversation between protagonists explores cultural competence alongside the notion of 'discovery', and the potential of the Tidal Model to provide a vehicle for successful cultural boundary surfing. PMID:20509812

  2. Downscaling surfing conditions in nearshore areas: seasonal, interannual and long term variability

    NASA Astrophysics Data System (ADS)

    Losada, I.; Espejo, A.; Mendez, F.

    2012-12-01

    During the last years several artificial surf reefs have been constructed. Most of them have had slight effect on improving surf quality and in some cases the results have not been enough satisfactory. One cause of this lack of success can be blamed to an incipient design and construction technique but also because the location of these structures responds to socio-economic principles rather than in oceanographic ones. This work describes a hybrid downscaling method used to get detailed tracing spectral wave and wind data in order to determine historical surf quality time series in a regional (10-200 km) or a local scale. Our assessment is conducted by means of an objective and standardized index on the basis of expert judgment that takes into account the multivariate character of the surf resource. The availability of long hourly time series (more than 60 years) of the surf quality allows the statistical analysis at any particular spot. Thus, we offer a reliable tool for identifying optimum reef location, and determining spatial patterns of surf consistency in terms of seasonal, interannual and long term variability. This method have been applied in the north-eastern coast of Spain identifying world class spots like Mundaka and other places where in spite of occurring good wave-wind conditions there is no bathymetric anomalies able to produce peeling waves. This method provides the decision making process when planning an artificial surf reef construction and at the same time offers useful information for coastal management and surf related stakeholders.

  3. Social Networking Sites' Influence on Travelers' Authentic Experience a Case Study of Couch Surfing

    ERIC Educational Resources Information Center

    Liu, Xiao

    2013-01-01

    This study explored travelers' experiences in the era of network hospitality 2.0 using CouchSurfing.org as a case study. The following research questions guided this study: 1) what experience does CouchSurfing create for travelers before, during and after their travel? 2) how does couch surfers' experience relate to authenticity in context of…

  4. Astrophysics: Illuminating brown dwarfs

    NASA Astrophysics Data System (ADS)

    Showman, Adam P.

    2016-05-01

    Objects known as brown dwarfs are midway between stars and planets in mass. Observations of a hot brown dwarf irradiated by a nearby star will help to fill a gap in our knowledge of the atmospheres of fluid planetary objects. See Letter p.366

  5. WISE and Brown Dwarfs

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, J. Davy; WISE Team

    2009-05-01

    The search for the nearest and coolest brown dwarfs will use WISE's two short-wavelength channels (W1 and W2), which are optimized for brown dwarf detection. W1 samples the methane fundamental absorption band at 3.3 microns, and W2 measures the relatively opacity-free portion of the brown dwarf atmosphere near 4.7 microns. Cool brown dwarfs will thus have very red [W1]-[W2] colors, maximizing our chances of identifying them. Extrapolating preferred mass functions to very low masses and assuming that the star formation rate has been constant over the last 10 Gyr, we can predict the number of brown dwarfs WISE is expected to image. At spectral types later than T7 (Teff > 850K), WISE is expected to find 500 brown dwarfs, which makes WISE uniquely suited among future surveys to measure the low-mass limit of star formation for the first time. This sample will also show whether a new spectral class beyond T, dubbed "Y", is needed at the lowest temperatures. Although the primary six-month WISE mission will cover the entire sky once, WISE should have sufficient cryogen to perform a second, complete pass of the sky. In this case, the identification of nearby brown dwarfs need not rely solely on color selection. Kinematics (proper motion) and geometry (parallax) can also be used to distinguish our closest brown dwarf neighbors, one of which may lie less distant than Proxima Centauri or even fall within our own Oort Cloud.

  6. Effect of Surface Preparation on CLAM/CLAM Hot Isostatic Pressing diffusion bonding joints

    NASA Astrophysics Data System (ADS)

    Li, C.; Huang, Q.; Zhang, P.

    2009-04-01

    Surface preparation is essential for the Hot Isostatic Pressing (HIP) diffusion bonding of RAFM steels. Hot Isostatic Pressing (HIP) diffusion bonding experiments on China Low Activation Martensitic (CLAM) steel was performed to study the effect of surface preparation. A few approaches such as hand lapping, dry-milling and grinding etc., were used to prepare the faying surfaces of the HIP joints. Different sealing techniques were used as well. The HIP parameters were 150 MPa/3 h/1150 °C. After post HIP heat treatment (PHHT), the tensile and Charpy impact tests were carried out. The results showed that hand lapping was not suitable to prepare the faying surfaces of HIP diffusion bonding specimens although the surface roughness by hand lapping was very low.

  7. Wave Acceleration Induced Sediment Transport in the Surf Zone

    NASA Astrophysics Data System (ADS)

    Hoefel, F.; Elgar, S.

    2002-12-01

    A bedload sediment transport formulation (Drake and Calantoni, 2001) that accounts for the effects of near-bottom wave-orbital velocity acceleration skewness predicts onshore sandbar migration observed near Duck, NC. Including acceleration effects in an energetics sediment transport model results in improved skill in reproducing cross-shore sandbar migration patterns observed over a 40 day period during which the bar moved both offshore in storms and onshore between storms. These results suggest that skewed acceleration time series, associated with the pitched forward shapes of nearly breaking and broken waves, play an important role in wave-induced sediment transport in the surf zone. The passage of steep wave fronts results in spikes in acceleration when orbital velocities are directed onshore, producing strong horizontal pressure gradient forces that act on the sediment. In contrast to velocity skewness, which remains approximately constant across the surf zone, acceleration skewness is observed to increase from small values offshore to a maximum near the bar crest, and then to decrease toward the shoreline, producing cross-shore spatial gradients in acceleration-driven transport that are consistent with erosion offshore and accretion onshore of the bar crest. As the sandbar migrates shoreward, the maximum of acceleration skewness also moves onshore, causing a positive feedback mechanism that promotes continued onshore sediment transport motion provided the forcing remains constant. Funded by ARO, ONR, and NOPP.

  8. Information surfing with the JHU/APL coherent imager

    NASA Astrophysics Data System (ADS)

    Ratto, Christopher R.; Shipley, Kara R.; Beagley, Nathaniel; Wolfe, Kevin C.

    2015-05-01

    The ability to perform remote forensics in situ is an important application of autonomous undersea vehicles (AUVs). Forensics objectives may include remediation of mines and/or unexploded ordnance, as well as monitoring of seafloor infrastructure. At JHU/APL, digital holography is being explored for the potential application to underwater imaging and integration with an AUV. In previous work, a feature-based approach was developed for processing the holographic imagery and performing object recognition. In this work, the results of the image processing method were incorporated into a Bayesian framework for autonomous path planning referred to as information surfing. The framework was derived assuming that the location of the object of interest is known a priori, but the type of object and its pose are unknown. The path-planning algorithm adaptively modifies the trajectory of the sensing platform based on historical performance of object and pose classification. The algorithm is called information surfing because the direction of motion is governed by the local information gradient. Simulation experiments were carried out using holographic imagery collected from submerged objects. The autonomous sensing algorithm was compared to a deterministic sensing CONOPS, and demonstrated improved accuracy and faster convergence in several cases.

  9. Habitat use by larval fishes in a temperate South African surf zone

    NASA Astrophysics Data System (ADS)

    Watt-Pringle, Peter; Strydom, Nadine A.

    2003-12-01

    Larval fishes were sampled in the Kwaaihoek surf zone on the south east coast of South Africa. On six occasions between February and May 2002, larval fishes were collected in two habitat types identified in the inner surf zone using a modified beach-seine net. The surf zone habitats were classified as either sheltered trough areas or adjacent exposed surf areas. Temperature, depth and current measurements were taken at all sites. Trough habitats consisted of a depression in surf topography characterised by reduced current velocities and greater average depth than adjacent surf areas. In total, 325 larval fishes were collected. Of these, 229 were collected in trough and 96 in surf habitats. At least 22 families and 37 species were represented in the catch. Dominant families were the Mugilidae, Sparidae, Atherinidae, and Engraulidae. Dominant species included Liza tricuspidens and Liza richardsonii (Mugilidae), Rhabdosargus holubi and Sarpa salpa (Sparidae), Atherina breviceps (Atherinidae) and Engraulis japonicus (Engraulide). Mean CPUE of postflexion larvae of estuary-dependent species was significantly greater in trough areas. The proportion of postflexion larval fishes in trough habitat was significantly greater than that of preflexion stages, a result that was not apparent in surf habitat sampled. CPUE of postflexion larvae of estuary-dependent fishes was negatively correlated with current magnitude and positively correlated with habitat depth. Mean body length of larval fishes was significantly greater in trough than in surf habitats. These results provide evidence that the CPUE of postflexion larvae of estuary-dependent fishes is higher in trough habitat in the surf zone and this may be indicative of active habitat selection for areas of reduced current velocity/wave action. The implications of this behaviour for estuarine recruitment processes are discussed.

  10. Blue compact dwarfs - Extreme dwarf irregular galaxies

    NASA Technical Reports Server (NTRS)

    Thuan, Trinh X.

    1987-01-01

    Observational data on the most extreme members of the irregular dwarf (dI) galaxy class, the blue compact dwarfs (BCDs), are characterized, reviewing the results of recent investigations. The properties of the young stellar population, the ionized gas, the older star population, and the gas and dust of BCDs are contrasted with those of other dIs; BCD morphology is illustrated with sample images; and the value of BCDs (as nearby 'young' chemically unevolved galaxies) for studies of galaxy formation, galactic evolution, and starburst triggering mechanisms is indicated.

  11. Development status of CLAM steel for fusion application

    NASA Astrophysics Data System (ADS)

    Huang, Qunying

    2014-12-01

    The China low activation martensitic (CLAM) steel is being developed at the Institute of Nuclear Energy Safety Technology (INEST) under wide collaboration within China. Significant R&D work on CLAM steel was carried out to help make it suitable for industrial applications. The effect of refining processes and thermal aging on composition, microstructures and mechanical properties were investigated. Material properties before irradiation including impact, fracture toughness, thermal aging, creep and fatigue properties etc. were assessed. A series of irradiation tests in the fission reactor HFETR in Chengdu up to 2 dpa and in the spallation neutron source SINQ in Paul Scherrer Institute up to 20 dpa were performed. PbLi corrosion tests for more than 10,000 h were done in the DRAGON-I and PICOLO loops. Fabrication techniques for a test blanket module (TBM) are being developed and a 1/3 scale TBM prototype is being fabricated with CLAM steel. Recent progresses on the development status of this steel are presented here. The code qualification of CLAM steel is under plan for its final application in ITER-TBM and DEMO in the future.

  12. Photosymbiotic giant clams are transformers of solar flux

    PubMed Central

    Holt, Amanda L.; Vahidinia, Sanaz; Gagnon, Yakir Luc; Morse, Daniel E.; Sweeney, Alison M.

    2014-01-01

    ‘Giant’ tridacnid clams have evolved a three-dimensional, spatially efficient, photodamage-preventing system for photosymbiosis. We discovered that the mantle tissue of giant clams, which harbours symbiotic nutrition-providing microalgae, contains a layer of iridescent cells called iridocytes that serve to distribute photosynthetically productive wavelengths by lateral and forward-scattering of light into the tissue while back-reflecting non-productive wavelengths with a Bragg mirror. The wavelength- and angle-dependent scattering from the iridocytes is geometrically coupled to the vertically pillared microalgae, resulting in an even re-distribution of the incoming light along the sides of the pillars, thus enabling photosynthesis deep in the tissue. There is a physical analogy between the evolved function of the clam system and an electric transformer, which changes energy flux per area in a system while conserving total energy. At incident light levels found on shallow coral reefs, this arrangement may allow algae within the clam system to both efficiently use all incident solar energy and avoid the photodamage and efficiency losses due to non-photochemical quenching that occur in the reef-building coral photosymbiosis. Both intra-tissue radiometry and multiscale optical modelling support our interpretation of the system's photophysics. This highly evolved ‘three-dimensional’ biophotonic system suggests a strategy for more efficient, damage-resistant photovoltaic materials and more spatially efficient solar production of algal biofuels, foods and chemicals. PMID:25401182

  13. The Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) Experiment

    NASA Technical Reports Server (NTRS)

    Smith, William L., Jr.; Charlock, Thomas; Wielicki, Bruce; Kahn, Ralph; Martins, J. Vanderlei; Gatebe, Charles; Hobbs, Peter V.; Purgold, G. Carl; Redemann, Jens; Remer, Lorraine

    2004-01-01

    NASA has developed an Earth Observing System (EOS) consisting of a series of satellites designed to study global change from space. The EOS flagship is the EOS TERRA satellite, launched in December 1999, equipped with five unique sensors to monitor and study the Earth s heat budget and many of the key controlling variables governing the Earth's climate system. CLAMS, the Chesapeake Lighthouse and Aircraft Measurements for Satellites field campaign was conducted from NASA Wallops Flight Facility and successfully executed over the middle Atlantic eastern seaboard from July 10 August 2, 2001. CLAMS is primarily a shortwave closure experiment designed to validate and improve EOS TERRA satellite data products being derived from three sensors: CERES (Clouds and Earth's Radiant Energy System), MISR (Multi-angle Imaging Spectro-Radiometer) and MODIS (MODerate Resolution Imaging Spectroradiometer). CLAMS is jointly sponsored by the CERES, MISR and MODIS instrument teams and the NASA GEWEX Global Aerosol Climatology Project (GACP). CLAMS primary objectives are to validate satellite-based retrievals of aerosol properties and vertical profiles of radiative flux, temperature and water vapor. Central to CLAMS measurement strategy is the Chesapeake Lighthouse, a stable sea platform located in the Atlantic Ocean, 13 miles east of Virginia Beach near the mouth of the Chesapeake Bay and the site of an ongoing CERES Ocean Validation Experiment (COVE). Six research aircraft were deployed to make detailed measurements of the atmosphere and ocean surface in the vicinity of COVE, over the surrounding ocean, over nearby NOAA buoys and over a few land sites. The measurements are used to validate and provide ground truth for simultaneous products being derived from TERRA data, a key step toward an improved understanding and ability to predict changes in the Earth's climate. One of the two CERES instruments on-board TERRA was programmed for Rotating Azimuth Plane Scans (RAPS) during CLAMS

  14. Vesicomyid Clams Alter Biogeochemical Processes at Pacific Methane Seeps

    NASA Astrophysics Data System (ADS)

    Bertics, V. J.; Treude, T.; Ziebis, W.

    2007-12-01

    There exists a close relationship between fluid flow, biogeochemistry, and biota in seep sediments. Upwelling of methane and sulfide-rich fluids supports abundant macrofauna species harboring thiotrophic or methanotrophic symbionts. Variations in fluid flow, thus supply of methane and sulfide, are considered key factors controlling benthic communities. Vesicomyid clams harbor thiotrophic symbionts in their gills, which are supplied with oxygen from the surrounding water and hydrogen sulfide from the sediment. The clams are capable of extending their foot into the sediment to tap sulfide sources in deeper layers, consequently affecting water-sediment solute exchange. Because seep fluids are generally depleted in sulfate compared to seawater, this bioturbation activity may enhance the supply of sulfate to otherwise sulfate-limited sediments, thus boosting microbial activity of sulfate reduction (SR) coupled to anaerobic oxidation of methane (AOM). The goal of this study was to investigate the activity of three species of vesicomyid clams ( Calyptogena pacifica, C. kilmeri, C. gigas) from three methane seep habitats (Eel River Basin, Hydrate Ridge, Monterey Bay Canyon) and to evaluate its effect on biogeochemical processes. Sediment cores and clams were collected using the submersible Alvin or the ROV Jason, during three cruises with the R/V Atlantis in July and October 2006 and July 2007 (AT 15-7, AT 15-11, and AT 15-20). We performed high-resolution measurements of geochemical gradients in intact sediment cores using microsensors (O2, H2S, pH, redox potential). The cores were then sliced (1 cm intervals) for detailed chemical and microbiological analyses. Parallel cores were used to determine microbial activity (AOM, SR) with radioactive tracers. For detailed laboratory investigations, clams were kept in narrow aquaria (15 cm x 20 cm x 5 cm) in the ship's cold room. The front of the aquaria was perforated with holes at 1 cm resolution. These silicone-filled holes

  15. Patterns in Clam Excurrent Siphon Velocity According to External Environmental Cues

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; Delavan, S. K.

    2010-11-01

    This study attempts to determine the patterns and/or randomness of the excurrent velocity of actively feeding clams, Mercenaria mercenaria. We hypothesize that clams alter their feeding current velocity patterns or randomness according to external cues in the environment such as hydrodynamic characteristics, density of the clam patch, and presence of predators in the upstream flow. A PIV system measured vector fields for two-dimensional planes that bisect the clam excurrent siphons, and time records were extracted at the siphon exit position. Fractal and lacunarity analysis of the jet velocity time records revealed that clams alter their jet excurrent velocity unsteadiness according to the horizontal crossflow velocity. The results also reveal that the effect of clam patch density on the feeding activity was dependent on the size of the organism. This size/density dependent relationship suggests that predation by blue crabs dominates the system since larger clams are no longer susceptible to blue crab predation, whereas clams of all sizes are susceptible to whelk predation. Finally, clams increase the randomness of their excurrent jet velocity values when predator cues are located in the upstream flume flow. This suggests that the presence of predators elicits clam behavior that promotes the mixing and dilution of their chemical metabolites.

  16. When White Dwarfs Collide

    NASA Astrophysics Data System (ADS)

    Hawley, Wendy Phyllis

    2012-01-01

    3D models of white dwarf collisions are used to assess the likelihood of double-degenerate mergers as progenitors for Type Ia supernovae (henceforth SNIa) and to identify observational signatures of double-degenerate collisions. Observations of individual SNIa, SNIa rates in different galaxy types, and double white dwarf binary systems suggest that mergers or collisions between two white dwarfs play a role in the overall SNIa population. Given the possibility of two progenitor systems (single-degenerate and double-degenerate), the sample of SNIa used in cosmological calcula- tions needs to be carefully examined. To improve calculations of cosmological parameters, the development of calibrated diagnostics for double-degenerate progenitor SNIa is essential. Head-on white dwarf collision simulations are used to provide an upper limit on the 56Ni production in white dwarf collisions. In chapter II, I explore zero impact parameter collisions of white dwarfs using the Eulerian grid code FLASH. The initial 1D white dwarf profiles are created assuming hydrostatic equilibrium and a uniform composition of 50% 12C and 50% 16O. The masses range from 0.64 to 0.81 solar masses and have an isothermal temperature of 107 K. I map these 1D models onto a 3D grid, where the dimensions of the grid are each eight times the white dwarf radius, and the dwarfs are initially placed four white dwarf radii apart (center to center). To provide insight into a larger range of physical possibilities, I also model non-zero impact parameter white dwarf collisions (Chapter III). Although head-on white dwarf collisions provide an upper limit on 56Ni production, non-zero impact parameter collisions provide insight into a wider range of physical scenarios. The initial conditions (box size, initial separation, composition, and initial temperature) are identical to those used for the head-on collisions (Chapter II) for the same range of masses. For each mass pair- ing, collision simulations are carried

  17. M dwarfs: Theoretical work

    NASA Technical Reports Server (NTRS)

    Mullan, Dermott J.

    1987-01-01

    Theoretical work on the atmospheres of M dwarfs has progressed along lines parallel to those followed in the study of other classes of stars. Such models have become increasingly sophisticated as improvements in opacities, in the equation of state, and in the treatment of convection were incorporated during the last 15 to 20 years. As a result, spectrophotometric data on M dwarfs can now be fitted rather well by current models. The various attempts at modeling M dwarf photospheres in purely thermal terms are summarized. Some extensions of these models to include the effects of microturbulence and magnetic inhomogeneities are presented.

  18. Surf zone diatoms: A review of the drivers, patterns and role in sandy beaches food chains

    NASA Astrophysics Data System (ADS)

    Odebrecht, Clarisse; Du Preez, Derek R.; Abreu, Paulo Cesar; Campbell, Eileen E.

    2014-10-01

    The accumulation of high biomass of diatoms in the surf zone is a characteristic feature of some sandy beaches where the wave energy is sufficiently high. A few species of diatoms, called surf diatoms, thrive in this harsh environment. The main processes driving the spatial and temporal distribution of surf diatoms as well as their standing biomass and growth were described twenty to thirty years ago based on studies conducted on the western coast of the United States of America and South African beaches. Since then, over fifty locations around the world have been reported to have surf diatom accumulations with most (three-quarters) of these being in the southern hemisphere. Their occurrence is controlled by physical and chemical factors, including wave energy, beach slope and length, water circulation patterns in the surf zone and the availability of nutrients to sustain the high biomass. The main forces driving the patterns of temporal variability of surf diatom accumulations are meteorological. In the short term (hours), the action of wind stress and wave energy controls the diatom accumulation. In the intermediate time scale (weeks to months), seasonal onshore winds of sufficient strength, as well as storm events are important. Furthermore, anthropogenic disturbances that influence the beach ecosystem as well as large-scale events, such as the El Niño Southern Oscillation, may lead to significant changes in surf diatom populations in the long term (inter-annual). Surf diatoms form the base of a short and very productive food chain in the inshore of the sandy beaches where they occur. However, the role of surf diatoms in the microbial food web is not clear and deserves further studies.

  19. Study of perkinsosis in the carpet shell clam Tapes decussatus in Galicia (NW Spain). II. Temporal pattern of disease dynamics and association with clam mortality.

    PubMed

    Villalba, Antonio; Casas, Sandra M; López, Carmen; Carballal, María J

    2005-07-18

    Temporal dynamics of the infection by Perkinsus olseni in a clam (Tapes decussatus) bed was studied over 5 yr (March 1996 to December 2000). Diagnostic techniques were compared to assess their suitability for epizootiological purposes. A technique based on incubation of 2 gill lamellae in Ray's fluid thioglycollate medium (RFTM) was more sensitive, quicker and cheaper than examination of histological sections. Incubation of the whole-clam soft tissues in RFTM allowed detection of very light infections that were not detected with incubation of only 2 gill lamellae. Nevertheless, the correlation between the infection intensity estimated by both RFTM incubations was high. Infection intensity was significantly and positively correlated with clam size/age. No infected clam smaller than 20 mm was found. There was an annual pattern of infection involving lower mean infection intensity and prevalence in winter and higher values for both variables from spring to autumn, with 2 main annual peaks in spring and late summer-early autumn. This temporal pattern was significantly associated with the seawater temperature. The annual spring peak of infection intensity occurred when seawater temperature was around 15 degrees C. Monthly mortality in the clam bed peaked in spring and summer--after peaks of P. olseni infection intensity and concurrently with high seawater temperature. A comparison of percentage mortality between clams from 2 sources (a perkinsosis-affected and a non-affected area) placed in the same clam bed revealed significantly higher mortality in the clams originating from the perkinsosis-affected area. PMID:16119895

  20. Clams (Corbicula fluminea) as bioindicators of fecal contamination with Cryptosporidium and Giardia spp. in freshwater ecosystems in California.

    PubMed

    Miller, Woutrina A; Atwill, Edward R; Gardner, Ian A; Miller, Melissa A; Fritz, Heather M; Hedrick, Ronald P; Melli, Ann C; Barnes, Nicole M; Conrad, Patricia A

    2005-05-01

    This study evaluated clams as bioindicators of fecal protozoan contamination using three approaches: (i) clam tissue spiking experiments to compare several detection techniques; (ii) clam tank exposure experiments to evaluate clams that had filtered Cryptosporidium oocysts from inoculated water under a range of simulated environmental conditions; (iii) sentinel clam outplanting to assess the distribution and magnitude of fecal contamination in three riverine systems in California. Our spiking and tank experiments showed that direct fluorescent antibody (DFA), immunomagnetic separation (IMS) in combination with DFA, and PCR techniques could be used to detect Cryptosporidium in clam tissues. The most analytically sensitive technique was IMS concentration with DFA detection of oocysts in clam digestive gland tissues, which detected 10 oocysts spiked into a clam digestive gland 83% of the time. In the tank experiment, oocyst dose and clam collection time were significant predictors for detecting Cryptosporidium parvum oocysts in clams. In the wild clam study, Cryptosporidium and Giardia were detected in clams from all three study regions by IMS-DFA analysis of clam digestive glands, with significant variation by sampling year and season. The presence of C. parvum DNA in clams from riverine ecosystems was confirmed with PCR and DNA sequence analysis. PMID:15862580

  1. Droplets move over viscoelastic substrates by surfing a ridge

    PubMed Central

    Karpitschka, S.; Das, S.; van Gorcum, M.; Perrin, H.; Andreotti, B.; Snoeijer, J. H.

    2015-01-01

    Liquid drops on soft solids generate strong deformations below the contact line, resulting from a balance of capillary and elastic forces. The movement of these drops may cause strong, potentially singular dissipation in the soft solid. Here we show that a drop on a soft substrate moves by surfing a ridge: the initially flat solid surface is deformed into a sharp ridge whose orientation angle depends on the contact line velocity. We measure this angle for water on a silicone gel and develop a theory based on the substrate rheology. We quantitatively recover the dynamic contact angle and provide a mechanism for stick–slip motion when a drop is forced strongly: the contact line depins and slides down the wetting ridge, forming a new one after a transient. We anticipate that our theory will have implications in problems such as self-organization of cell tissues or the design of capillarity-based microrheometers. PMID:26238436

  2. Surfing through Hyperspace - Understanding Higher Universes in Six Easy Lessons

    NASA Astrophysics Data System (ADS)

    Pickover, Clifford A.

    1999-09-01

    Do a little armchair time-travel, rub elbows with a four-dimensional intelligent life form, or stretch your mind to the furthest corner of an uncharted universe. With this astonishing guidebook, Surfing Through Hyperspace , you need not be a mathematician or an astrophysicist to explore the all-but-unfathomable concepts of hyperspace and higher-dimensional geometry.No subject in mathematics has intrigued both children and adults as much as the idea of a fourth dimension. Philosophers and parapsychologists have meditated on this mysterious space that no one can point to but may be all around us. Yet this extra dimension has a very real, practical value to mathematicians and physicists who use it every day in their calculations. In the tradtion of Flatland , and with an infectious enthusiasm, Clifford Pickover tackles the problems inherent in our 3-D brains trying to visualize a 4-D world, muses on the religious implications of the existence of higher-dimensional consciousness, and urges all curious readers to venture into "the unexplored territory lying beyond the prison of the obvious." Pickover alternates sections that explain the science of hyperspace with sections that dramatize mind-expanding concepts through a fictional dialogue between two futuristic FBI agents who dabble in the fourth dimension as a matter of national security. This highly accessible and entertaining approach turns an intimidating subject into a scientific game open to all dreamers.Surfing Through Hyperspace concludes with a number of puzzles, computer experiments and formulas for further exploration, inviting readers to extend their minds across this inexhaustibly intriguing scientific terrain.

  3. Surfing through Hyperspace - Understanding Higher Universes in Six Easy Lessons

    NASA Astrophysics Data System (ADS)

    Pickover, Clifford A.

    2001-05-01

    Do a little armchair time-travel, rub elbows with a four-dimensional intelligent life form, or stretch your mind to the furthest corner of an uncharted universe. With this astonishing guidebook, Surfing Through Hyperspace , you need not be a mathematician or an astrophysicist to explore the all-but-unfathomable concepts of hyperspace and higher-dimensional geometry.No subject in mathematics has intrigued both children and adults as much as the idea of a fourth dimension. Philosophers and parapsychologists have meditated on this mysterious space that no one can point to but may be all around us. Yet this extra dimension has a very real, practical value to mathematicians and physicists who use it every day in their calculations. In the tradition of Flatland , and with an infectious enthusiasm, Clifford Pickover tackles the problems inherent in our 3-D brains trying to visualize a 4-D world, muses on the religious implications of the existence of higher-dimensional consciousness, and urges all curious readers to venture into "the unexplored territory lying beyond the prison of the obvious." Pickover alternates sections that explain the science of hyperspace with sections that dramatize mind-expanding concepts through a fictional dialogue between two futuristic FBI agents who dabble in the fourth dimension as a matter of national security. This highly accessible and entertaining approach turns an intimidating subject into a scientific game open to all dreamers.Surfing Through Hyperspace concludes with a number of puzzles, computer experiments and formulas for further exploration, inviting readers to extend their minds across this inexhaustibly intriguing scientific terrain.

  4. Image characterization and target recognition in the surf zone environment

    NASA Astrophysics Data System (ADS)

    Nevis, Andrew J.

    1996-05-01

    The surf zone environment represents a very difficult challenge for electro-optic surveillance programs. Data from these programs have been shown to contain dense clutter from vegetation, biological factors (fish), and man-made objects, and is further complicated by the water to land transition which has a significant impact on target signal-to-noise ratios (SNR). Also, targets can be geometrically warped from the sea surface and by occlusion from sand and breaking waves. The Program Executive Office Mine Warfare (PMO-210) recently sponsored a test under the Magic Lantern Adaptation (MLA) program to collect surf zone data. Analysis of the data revealed a dilemma for automatic target recognition algorithms; threshold target features high enough to reduce high false alarm rates from land clutter or low enough to detect and classify underwater targets. Land image typically have high SNR clutter with crisp edges while underwater images have lower SNR clutter with blurred edges. In an attempt to help distinguish between land and underwater images, target feature thresholds were made to vary as a function of the SNR of image features within images and as a function of a measure of the edge crispness of the image features. The feasibility of varying target feature thresholds to reduce false alarm rates was demonstrated on a target recognition program using a small set of MLA data. Four features were developed based on expected target shape and resolution: a contrast difference measure between circular targets and their local backgrounds, a signal-to-noise ratio, a normalized correlation, and a target circularity measure. Results showed a target probability of detection and classification (Pdc) of 50 - 78% with false alarms per frame of less than 4%.

  5. Military personnel recognition system using texture, colour, and SURF features

    NASA Astrophysics Data System (ADS)

    Irhebhude, Martins E.; Edirisinghe, Eran A.

    2014-06-01

    This paper presents an automatic, machine vision based, military personnel identification and classification system. Classification is done using a Support Vector Machine (SVM) on sets of Army, Air Force and Navy camouflage uniform personnel datasets. In the proposed system, the arm of service of personnel is recognised by the camouflage of a persons uniform, type of cap and the type of badge/logo. The detailed analysis done include; camouflage cap and plain cap differentiation using gray level co-occurrence matrix (GLCM) texture feature; classification on Army, Air Force and Navy camouflaged uniforms using GLCM texture and colour histogram bin features; plain cap badge classification into Army, Air Force and Navy using Speed Up Robust Feature (SURF). The proposed method recognised camouflage personnel arm of service on sets of data retrieved from google images and selected military websites. Correlation-based Feature Selection (CFS) was used to improve recognition and reduce dimensionality, thereby speeding the classification process. With this method success rates recorded during the analysis include 93.8% for camouflage appearance category, 100%, 90% and 100% rates of plain cap and camouflage cap categories for Army, Air Force and Navy categories, respectively. Accurate recognition was recorded using SURF for the plain cap badge category. Substantial analysis has been carried out and results prove that the proposed method can correctly classify military personnel into various arms of service. We show that the proposed method can be integrated into a face recognition system, which will recognise personnel in addition to determining the arm of service which the personnel belong. Such a system can be used to enhance the security of a military base or facility.

  6. 50 CFR 648.4 - Vessel permits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... under § 648.107. (4) Surf clam and ocean quahog vessels. Any vessel of the United States that fishes for surf clams or ocean quahogs, except vessels taking surf clams and ocean quahogs for personal use or fishing exclusively within state waters, must have been issued and carry on board a valid surf clam...

  7. Dwarfs in ancient Egypt.

    PubMed

    Kozma, Chahira

    2006-02-15

    Ancient Egypt was one of the most advanced and productive civilizations in antiquity, spanning 3000 years before the "Christian" era. Ancient Egyptians built colossal temples and magnificent tombs to honor their gods and religious leaders. Their hieroglyphic language, system of organization, and recording of events give contemporary researchers insights into their daily activities. Based on the record left by their art, the ancient Egyptians documented the presence of dwarfs in almost every facet of life. Due to the hot dry climate and natural and artificial mummification, Egypt is a major source of information on achondroplasia in the old world. The remains of dwarfs are abundant and include complete and partial skeletons. Dwarfs were employed as personal attendants, animal tenders, jewelers, and entertainers. Several high-ranking dwarfs especially from the Old Kingdom (2700-2190 BCE) achieved important status and had lavish burial places close to the pyramids. Their costly tombs in the royal cemeteries and the inscriptions on their statutes indicate their high-ranking position in Egyptian society and their close relation to the king. Some of them were Seneb, Pereniankh, Khnumhotpe, and Djeder. There were at least two dwarf gods, Ptah and Bes. The god Ptah was associated with regeneration and rejuvenation. The god Bes was a protector of sexuality, childbirth, women, and children. He was a favored deity particularly during the Greco-Roman period. His temple was recently excavated in the Baharia oasis in the middle of Egypt. The burial sites and artistic sources provide glimpses of the positions of dwarfs in daily life in ancient Egypt. Dwarfs were accepted in ancient Egypt; their recorded daily activities suggest assimilation into daily life, and their disorder was not shown as a physical handicap. Wisdom writings and moral teachings in ancient Egypt commanded respect for dwarfs and other individuals with disabilities. PMID:16380966

  8. Development of functional trait biomarkers for trace metal exposure in freshwater clams (Musculium spp.).

    PubMed

    Schoonover, Cody M; Wieker, Jessica; Pope, Rachelle; Brown, Chelsea; Cooper, Emily; DeWitt, Jariel; Gunselman, Samuel; Jensen, Cory; Stevens, Whitney; Yri, Jenae; Nezat, Carmen; Joyner-Matos, Joanna

    2016-10-01

    Exposure to trace metals typically causes oxidative stress; these consequences are better-characterized in estuarine and marine species than in freshwater species. How cellular-level responses to metal pollution influence whole-organism and population-level traits is poorly understood. We tested whether exposure to single metals (zinc and cadmium) and to metal mixtures (water in equilibrium with sediment from a highly polluted lake) alters two ecologically-relevant traits in freshwater clams, locomotion and reproduction. Fingernail clams (Musculium spp.) from unimpacted habitats were exposed to single metals and the metal mixture for up to 49days. The single metal doses (≤5mg/L Zn and ≤20μg/L Cd) were not toxicologically meaningful as clam survival, burial, and climbing activity did not differ across treatments. Water in equilibrium with the lake sediment contained cadmium, copper, lead, and zinc. Clams exposed to this metal mixture had decreased climbing activity but no change in burial activity. Metal-exposed clams had lower fecundity (number of shelled juveniles extruded by adult clams) and patterns in metal accumulation corresponded with lake sediment dose and clam activity. In contrast to the functional traits, stress protein expression and whole-clam glycogen content did not vary across treatment groups. These results indicate that fingernail clams of the genus Musculium are appropriate for development as sentinel species for metal pollution and can serve as a model for determining how metal pollution alters metabolic allocation patterns in freshwater organisms. PMID:27085374

  9. Hsp 70 in the soft shell clam (Mya arenaria): Potential as a biomarker of field contamination

    SciTech Connect

    Clayton, M.E.; Dworak, H.A.; McDowell, J.E.

    1995-12-31

    Soft shell clams (Mya arenaria) were collected from 2 contaminated and 2 control sites in Massachusetts at 4 time periods, extending over a 30{degree}C temperature range. Populations at New Bedford Harbor were exposed to PCBs, PAHs, and heavy metals and populations at the Cotuit Bay Shores Beach Club were exposed to an unknown quantity and composition of petroleum hydrocarbons. Heat shock protein (hsp) 70 was measured in the gill of 20 clams per site by ELISA, using a commercially available monoclonal antibody. Expression of hsp 70 was variable between individual clams collected from the same site. Significance of the variables site and month was tested by one-way and two-way ANOVA; site, month, and site by month interaction were all significant. The significant interaction term meant that it was necessary to hold the month variable constant in order to test the hypothesis that clams from the contaminated sites contained more heat shock proteins than clams from the corresponding control sites. In general, the contaminated clams contained a higher concentration of hsp 70 than clams from the control sites, with New Bedford Harbor exhibiting the highest levels. Seasonal differences which could be responsible for the month effect include heat shock, food availability, and reproductive condition. In order to use heat shock protein expression as a biomarker of exposure to contaminants in the field, it is necessary to compare clams from contaminated sites to clams from control sites sampled at the same time.

  10. Sandy beach surf zones: An alternative nursery habitat for 0-age Chinook salmon

    NASA Astrophysics Data System (ADS)

    Marin Jarrin, J. R.; Miller, J. A.

    2013-12-01

    The role of each habitat fish use is of great importance to the dynamics of populations. During their early marine residence, Chinook salmon (Oncorhynchus tshawytscha), an anadromous fish species, mostly inhabit estuaries but also use sandy beach surf zones and the coastal ocean. However, the role of surf zones in the early life history of Chinook salmon is unclear. We hypothesized that surf zones serve as an alternative nursery habitat, defined as a habitat that consistently provides a proportion of a population with foraging and growth rates similar to those experienced in the primary nursery. First, we confirmed that juvenile Chinook salmon cohorts are simultaneously using both habitats by combining field collections with otolith chemical and structural analysis to directly compare size and migration patterns of juveniles collected in two Oregon (USA) estuaries and surf zones during three years. We then compared juvenile catch, diet and growth in estuaries and surf zones. Juveniles were consistently caught in both habitats throughout summer. Catches were significantly higher in estuaries (average ± SD = 34.3 ± 19.7 ind. 100 m-2) than surf zones (1.0 ± 1.5 ind. 100 m-2) and were positively correlated (r = 0.92). Size at capture (103 ± 15 mm fork length, FL), size at marine entry (76 ± 13 mm FL), stomach fullness (2 ± 2% body weight) and growth rates (0.4 ± 0.0 mm day-1) were similar between habitats. Our results suggest that when large numbers of 0-age Chinook salmon inhabit estuaries, juveniles concurrently use surf zones, which serve as an alternative nursery habitat. Therefore, surf zones expand the available rearing habitat for Chinook salmon during early marine residence, a critical period in the life history.

  11. CONTAMINATED SEDIMENT TESTING WITH THE BIVALVE, MULINA LATERALIS: CULTURE REFINEMENT FOR ORGANISM AVAILABILITY

    EPA Science Inventory

    Availability of test species for estuarine benthic assessment is limited; therefore, a method was developed by the U.S. Environmental Protection Agency for using the dwarf surf clam (Mulinia lateralis) to identify adverse biological effects of bulk estuarine sediments. A multilab...

  12. CONTAMINATED SEDIMENT TESTING WITH THE BIVLVE, MULINIA LATERLALIS: CULTURE REFINEMENT FOR ORGANISM AVAILABILITY

    EPA Science Inventory

    Availability of test species for estuarine benthic assessment is limited; therefore, a method was developed by the U.S. Environmental Protection Agency for utilizing the dwarf surf clam, Mulinia lateralis, to identify adverse biological effects of bulk estuarine sediments. A mult...

  13. Measurements of acoustic ambient noise in shallow water due to breaking surf

    NASA Astrophysics Data System (ADS)

    Wilson, O. B., Jr.; Wolf, S. N.; Ingenito, F.

    1982-12-01

    Horizontal directionality of ambient noise was measured at ranges up to 15 km from the south-eastern shore of Monterey Bay, California. Water depths at the sites ranged from 8 to 175 m. A steerable cardioid receiving pattern was formed using signals telemetered from dipole and omnidirectional hydrophones suspended from tethered buoys. With no nearby shipping, whenever the maximum of the cardioid pattern was directed toward the beach, noise levels in the frequency range from 20 Hz to 70 Hz were greater than those obtained when the maximum was directed seaward. This difference or anisotropy (seaward vs. shoreward), which depends on range from the beach, on frequency and on surf intensity, was 10 dB at 300 Hz at the 9 km site during very heavy surf. Surf beat was clearly audible when the cardioid maximum was steered shoreward at ranges as great as 2 km. During heavy surf, the omnidirectional ambient noise levels also increased significantly in the same frequency range at which the anisotropy is evident. The anisotropy effects diminish both in magnitude and in frequency range with lower wave height but are still observable during light surf. We have concluded that intense breaking surf can contribute significantly to ambient noise in fairly deep continental shelf waters.

  14. Qualitative Task Analysis to Enhance Sports Characterization: A Surfing Case Study

    PubMed Central

    Moreira, Miguel; Peixoto, César

    2014-01-01

    The aim of this study was to develop a Matrix of Analysis for Sports Tasks (MAST), regardless of the sports activity, based on practice classification and task analysis. Being this a qualitative research our main question was: in assessing sports’ structure is it possible to make the characterization of any discipline through context and individuals’ behaviours? The sample was within a surf discipline in a competition flowing having 5 of the top 16 Portuguese surfers training together. Based on a qualitative method, studying the surf as the main activity was an interpretative study case. The MAST was applied in four phases: taxonomy; tasks and context description; task analysis; teaching and performance strategies. Its application allowed the activities’ characterization through the observation, surfer’s opinions and bibliographical support. The triangulation of the data was used as an information data treatment. The elements were classified by the challenges proposed to the practitioners and the taxonomy was constituted by the sport activities, group, modality and discipline. Surf is a discipline of surfing which is a sliding sport modality, therefore, a nature sport. In the context description, we had the wave’s components and constraints and the surfboards’ qualities. Through task analysis we obtained a taxonomy of surf manoeuvres. The structural and functional analysis allowed finding solutions for learning of surf techniques with trampoline and skateboards because these fit in sliding sports. MAST makes possible the development of strategies that benefit teaching and performance intervention. PMID:25414757

  15. Simple estimate of entrainment rate of pollutants from a coastal discharge into the surf zone.

    PubMed

    Wong, Simon H C; Monismith, Stephen G; Boehm, Alexandria B

    2013-10-15

    Microbial pollutants from coastal discharges can increase illness risks for swimmers and cause beach advisories. There is presently no predictive model for estimating the entrainment of pollution from coastal discharges into the surf zone. We present a novel, quantitative framework for estimating surf zone entrainment of pollution at a wave-dominant open beach. Using physical arguments, we identify a dimensionless parameter equal to the quotient of the surf zone width l(sz) and the cross-flow length scale of the discharge la = M(j) (1/2)/U(sz), where M(j) is the discharge's momentum flux and U(sz) is a representative alongshore velocity in the surf zone. We conducted numerical modeling of a nonbuoyant discharge at an alongshore uniform beach with constant slope using a wave-resolving hydrodynamic model. Using results from 144 numerical experiments we develop an empirical relationship between the surf zone entrainment rate α and l(sz)/(la). The empirical relationship can reasonably explain seven measurements of surf zone entrainment at three diverse coastal discharges. This predictive relationship can be a useful tool in coastal water quality management and can be used to develop predictive beach water quality models. PMID:24006887

  16. Characteristics of vesicomyid clams and their environment at the Blake Ridge cold seep, South Carolina, USA

    USGS Publications Warehouse

    Heyl, Taylor P.; Gilhooly, William P.; Chambers, Randolph M.; Gilchrist, George W.; Macko, Stephen A.; Ruppel, Carolyn D.; Van Dover, Cindy L.

    2007-01-01

    Spatial distributions and patchiness of dominant megafaunal invertebrates in deep-sea seep environments may indicate heterogeneities in the flux of reduced chemical compounds. At the Blake Ridge seep off South Carolina, USA, the invertebrate assemblage includes dense populations of live vesicomyid clams (an undescribed species) as well as extensive clam shell beds (i.e. dead clams). In the present study, we characterized clam parameters (density, size-frequency distribution, reproductive condition) in relation to sulfur chemistry (sulfide and sulfate concentrations and isotopic compositions, pyrite and elemental sulfur concentrations) and other sedimentary metrics (grain size, organic content). For clams >5 mm, clam density was highest where the total dissolved sulfide concentration at 10 cm depth (ΣH2S10cm) was 0.4 to 1.1 mmol l–1; juvenile clams (2S10cm was lowest. Clams were reproductively capable across a broad range of ΣH2S10cm (0.1 to 6.4 mmol l–1), and females in the sampled populations displayed asynchronous gametogenesis. Sulfide concentrations in porewaters at the shell–sediment interface of cores from shell beds were high, 3.3 to 12.1 mmol l–1, compared to –1 sulfide concentrations at the clam–sediment interface in live clam beds. Concentration profiles for sulfide and sulfate in shell beds were typical of those expected where there is active microbial sulfate reduction. In clam beds, profiles of sulfide and sulfate concentrations were also consistent with rapid uptake of sulfide by the clams. Sulfate in shell beds was systematically enriched in 34S relative to that in clam beds due to microbial fractionation during sulfate reduction, but in clam beds, sulfate δ34S matched that of seawater (~20‰). Residual sulfide values in clam and shell beds were correspondingly depleted in 34S. Based on porewater sulfide concentrations in shell beds at the time of sampling, we suggest that clam mortality may have been due to an abrupt increase in

  17. Clamming up: environmental forces diminish the perceptive ability of bivalve prey.

    PubMed

    Smee, Delbert L; Weissburg, Marc J

    2006-06-01

    The lethal and nonlethal impacts of predators in marine systems are often mediated via reciprocal detection of waterborne chemical signals between consumers and prey. Local flow environments can enhance or impair the chemoreception ability of consumers, but the effect of hydrodynamics on detection of predation risk by prey has not been investigated. Using clams as our model organism, we investigated two specific questions: (1) Can clams decrease their mortality by responding to predators? (2) Do fluid forces affect the ability of clams to detect approaching predators? Previous research has documented a decrease in clam feeding (pumping) in response to a neighboring predator. We determined the benefits of this behavior to survivorship by placing clams in the field with knobbed whelk or blue crab predators caged nearby and compared mortality between these clams and clams near a cage-only control. Significantly more clams survived in areas containing a caged predator, suggesting that predator-induced alterations in feeding reduce clam mortality in the field. We ascertained the effect of fluid forces on clam perception of predators in a laboratory flume by comparing the feeding (pumping) behavior of clams in response to crabs and whelks in flows of 3 and 11 cm/s. Clams pumped significantly less in the presence of predators, but their reaction to blue crabs diminished in the higher velocity flow, while their response to whelks remained constant in both flows. Thus, clam reactive distance to blue crabs was affected by fluid forces, but hydrodynamic effects on clam perceptive distance was predator specific. After predators were removed, clams exposed to whelks took significantly longer to resume feeding than those exposed to blue crabs. Our results suggest that prey perception of predators can be altered by physical forces. Prey detection of predators is the underlying mechanism for trait-mediated indirect interactions (TMIIs), and recent research has documented the

  18. Asteroseismology of White Dwarf Stars

    NASA Technical Reports Server (NTRS)

    Hansen, Carl J.

    1997-01-01

    The primary purpose of this investigation has been to study various aspects of multimode pulsations in variable white dwarfs. In particular, nonlinear interactions among pulsation modes in white dwarfs (and, to some extent, in other variable stars), analysis of recent observations where such interactions are important, and preliminary work on the effects of crystallization in cool white dwarfs are reported.

  19. Large herbivores surf waves of green-up during spring.

    PubMed

    Merkle, Jerod A; Monteith, Kevin L; Aikens, Ellen O; Hayes, Matthew M; Hersey, Kent R; Middleton, Arthur D; Oates, Brendan A; Sawyer, Hall; Scurlock, Brandon M; Kauffman, Matthew J

    2016-06-29

    The green wave hypothesis (GWH) states that migrating animals should track or 'surf' high-quality forage at the leading edge of spring green-up. To index such high-quality forage, recent work proposed the instantaneous rate of green-up (IRG), i.e. rate of change in the normalized difference vegetation index over time. Despite this important advancement, no study has tested the assumption that herbivores select habitat patches at peak IRG. We evaluated this assumption using step selection functions parametrized with movement data during the green-up period from two populations each of bighorn sheep, mule deer, elk, moose and bison, totalling 463 individuals monitored 1-3 years from 2004 to 2014. Accounting for variables that typically influence habitat selection for each species, we found seven of 10 populations selected patches exhibiting high IRG-supporting the GWH. Nonetheless, large herbivores selected for the leading edge, trailing edge and crest of the IRG wave, indicating that other mechanisms (e.g. ruminant physiology) or measurement error inherent with satellite data affect selection for IRG. Our evaluation indicates that IRG is a useful tool for linking herbivore movement with plant phenology, paving the way for significant advancements in understanding how animals track resource quality that varies both spatially and temporally. PMID:27335416

  20. Two epizootic diseases in Chesapeake Bay commercial clams, Mya arenaria and Tagelus plebeius.

    PubMed

    Dungan, Christopher F; Hamilton, Rosalee M; Hudson, Karen L; McCollough, Carol B; Reece, Kimberly S

    2002-06-21

    Declining Chesapeake Bay harvests of softshell clams, together with historical and emerging reports of epizootic diseases in Mya arenaria, prompted a survey in summer 2000 of the health status of selected commercial clam populations. All sampled populations (8 M arenaria softshell clam, 2 Tagelus plebeius razor clam) were infected by Perkinsus sp. protozoans at prevalences ranging from 30 to 100% of sampled clams. Nucleotide sequences for the internal transcribed spacer (ITS) region of the rRNA gene complex were determined for clonal in vitro Perkinsus sp. isolates propagated from both M. arenaria and T plebeius. Multiple polymorphic sequences were amplified from each isolate, but phylogenetic analysis placed all sequences into 2 clades of a monophyletic group, which included both recently described clam parasites P. chesapeaki and P. andrewsi. Sequences amplified from each clonal isolate were found in both sister clades, one containing P. andrewsi and the other P. chesapeaki. Most (7 of 8) M. arenaria samples were also affected with disseminated neoplasia (DN), at prevalences of 3 to 37%, but neither T. plebeius sample showed DN disease. Disease mortalities projected for sampled clam populations, especially those affected by both diseases, may further deplete subtidal commercial clam populations in mesohaline portions of Chesapeake Bay. PMID:12152906

  1. MISR Browse Images: Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS)

    Atmospheric Science Data Center

    2016-06-13

    MISR Browse Images: Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS)   These MISR Browse images provide a quick visual overview of the region observed during the ... is found at the  CLAMS home page . The MISR Browse images from the nadir camera include paths 13, 14, and 15 for July 10 to August ...

  2. GERMINOMAS AND TERATOID SIPHON ANOMALIES IN SOFTSHELL CLAMS, MYA ARENARIA, ENVIRONMENTALLY EXPOSED TO HERBICIDES

    EPA Science Inventory

    Seminomas and dysgerminomas are episodic in softshell clams, Mya arenaria, from three Maine estuaries contaminated with herbicides. he first epizootic was discovered in 22% of clams collected as Searsport near Long Cove Brook and three culverts that conveyed heating oil and jet f...

  3. Factors affecting growth and survival of the asiatic clam Corbicula sp. under controlled laboratory conditions

    SciTech Connect

    Double, D.D.; Daly, D.S.; Abernethy, C.S.

    1983-04-01

    Growth of Corbicula sp. was determined in relation to food supply, water temperature, and clam size as an aid to researchers conducting chronic effects toxicity studies. Water temperatures for the two 84-day test series were 10, 20, and 30/sup 0/C. Linear models provided good relationships (r/sup 2/ > 0.90) between clam shell length (SL), total weight (TW), and wet/dry tissue weights. Clam growth was minimal during low phytoplankton densities (approx. 300 cells/ml), and all three size groups lost weight at 20 and 30/sup 0/C. Mortality of small clams at 30/sup 0/C was 100% after 71 days. At phytoplankton densities > 1000 cells/ml, overall differences in growth with respect to clam size and temperature were detectable at p < 0.01; growth of all clam groups was greatest at 30/sup 0/C. Small clams exhibited the greatest absolute increase in mean shell length at all test temperatures, and weight gains were similar to those of medium and large clams.

  4. 50 CFR 17.45 - Special rules-snails and clams. [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 2 2012-10-01 2012-10-01 false Special rules-snails and clams. 17.45 Section 17.45 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—snails and clams....

  5. 50 CFR 17.45 - Special rules-snails and clams. [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 2 2011-10-01 2011-10-01 false Special rules-snails and clams. 17.45 Section 17.45 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—snails and clams....

  6. 50 CFR 17.45 - Special rules-snails and clams. [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 2 2013-10-01 2013-10-01 false Special rules-snails and clams. 17.45 Section 17.45 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—snails and clams....

  7. 50 CFR 17.45 - Special rules-snails and clams. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 2 2010-10-01 2010-10-01 false Special rules-snails and clams. 17.45 Section 17.45 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—snails and clams....

  8. 50 CFR 17.45 - Special rules-snails and clams. [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 2 2014-10-01 2014-10-01 false Special rules-snails and clams. 17.45 Section 17.45 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—snails and clams....

  9. Surf zone entrainment, along-shore transport, and human health implications of pollution from tidal outlets

    NASA Astrophysics Data System (ADS)

    Grant, S. B.; Kim, J. H.; Jones, B. H.; Jenkins, S. A.; Wasyl, J.; Cudaback, C.

    2005-10-01

    Field experiments and modeling studies were carried out to characterize the surf zone entrainment and along-shore transport of pollution from two tidal outlets that drain into Huntington Beach and Newport Beach, popular public beaches in southern California. The surf zone entrainment and near-shore transport of pollutants from these tidal outlets appears to be controlled by prevailing wave conditions and coastal currents, and fine-scale features of the flow field around the outlets. An analysis of data from dye experiments and fecal indicator bacteria monitoring studies reveals that the along-shore flux of surf zone water is at least 50 to 300 times larger than the cross-shore flux of surf zone water. As a result, pollutants entrained in the surf zone hug the shore, where they travel significant distances parallel to the beach before diluting to extinction. Under the assumption that all surf zone pollution at Huntington Beach originates from two tidal outlets, the Santa Ana River and Talbert Marsh outlets, models of mass and momentum transport in the surf zone approximately capture the observed tidal phasing and magnitude of certain fecal indicator bacteria groups (total coliform) but not others (Escherichia coli and enterococci), implying the existence of multiple sources of, and/or multiple transport pathways for, fecal pollution at this site. The intersection of human recreation and near-shore pollution pathways implies that, from a human health perspective, special care should be taken to reduce the discharge of harmful pollutants from land-side sources of surface water runoff, such as tidal outlets and storm drains.

  10. Mercury accumulation in the clam, Galatea paradoxa (Born 1778) at the Volta estuary, Ghana.

    PubMed

    Obirikorang, K A; Amisah, S; Adjei-Boateng, D; Madkour, H A; Otchere, F A

    2010-11-01

    The concentration of mercury in the tissues of the clam, Galatea paradoxa at in the Volta estuary, Ghana, were analysed over an 18-month period, from March 2008 to August 2009. The concentrations were well below the International Human Consumption Advisory Limit of THg (0.5 μg/g wet weight). The concentrations in the tissues of the different clam size classes were between 6 and 18 times lower than the WHO Safety Reference Standard. Variation in the mean mercury concentration in the different clam size classes was not significant (p > 0.05) for clams from Aveglo but were highly significant (p < 0.0001) for clams from Ada, indicating a possible effect of size on accumulation. G. paradoxa is therefore suitable for human consumption based on the WHO Safety Reference Standards. PMID:20972534

  11. Barley Yellow Dwarf Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Barley yellow dwarf (BYD) is the most widespread and economically important virus disease of cereals. The viruses causing BYD were initially grouped based on common biological properties, including persistent and often strain-specific transmission by aphids and induction of yellowing symptoms. The...

  12. Barley Yellow Dwarf

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Barley yellow dwarf is the most economically important virus disease affecting most cereal crops world wide. This manuscript summarizes the current knowledge of the disease etiology, epidemiology and management. This information is incorporated into the latest revision of the American Phytopathologi...

  13. Dwarf Eye Disorder

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Johns Hopkins researchers at the Wilmer Eye Institute have discovered what appears to be the first human gene mutation that causes extreme farsightedness. The researchers report that nanophthalmos, Greek for "dwarf eye," is a rare, potentially blinding disorder caused by an alteration in a gene called MFRP that helps control eye growth and…

  14. Infestation of the clam Chione fluctifraga by the burrowing worm Polydora sp. nov. in laboratory conditions.

    PubMed

    Tinoco-Orta, Gissel Dalila; Cáceres-Martínez, Jorge

    2003-07-01

    Burrowing worms that belong to Polydora spp. infest marine mollusks cultured worldwide, causing problems for production and marketing. The clam Chione fluctifraga is semi-cultured in Bahía Falsa, Baja California, NW Mexico, and some clams harbor burrowing worms. The present study was carried out to determine the identity of the worm species infesting the clam, the infesting process by cohabitation of infested and non-infested clams in aquaria with a variety of substrates (fine sand, gross sand, plastic bag used for clam culture, and aquarium without substrate) and turbulence conditions, and the occurrence of architomy phenomena in connection with infestation of the clam. The burrowing worm was considered as a nova species due to its singular limbate neurosetae and notosetae in the setiger 5, hooks in the setiger 6, eyes not present, and general pigmentation, among other characteristics. Infestation was similar in all substrates and turbulence conditions, but it was more abundant on clams previously infested than on those free of worms, showing a preferential settlement of worm infesting stages on pre-infested clams. Regeneration was observed in all segments of the worm: anterior (metastomium), medium, and posterior (prostomium); the complete regeneration time occurred in 40 days. This is the first record of architomy in a species of Polydora and this phenomenon could account for the increase of infestation intensity in pre-infested clams at the end of the study period. Infestation of clams by settling polichaete in the conditions studied, and the architomy process in this worm species, shows its great infesting capacity. PMID:12877826

  15. Declining populations of the fingernail clam Musculium transversum in the upper Mississippi River

    USGS Publications Warehouse

    Wilson, D.M.; Naimo, T.J.; Weiner, J.G.; Anderson, R.V.; Sandheinrich, M.B.; Sparks, R.E.

    1995-01-01

    We examined recent temporal trends in the abundance of fingernail clams Musculium transversum (formerly Sphaerium transversum) in the upper Mississippi River. Historical data on densities of fingernail clams were obtained from regional scientists and published literature. We also sampled benthos in six navigation pools in summer 1991, finding very few fingernail clams. The combined data set, including historical data and sampling results, extended from 1973 to 1992 and was sufficient to statistically evaluate trends in densities of fingernail clams in eight pools. Populations of fingernail clams declined significantly in five of the eight pools examined (Pools 2, 5, 7, 9, and 19), which spanned a 700-km reach of river from St. Paul, Minnesota, to Keokuk, Iowa. Densities in Pool 19, which had the longest historical record on fingernail clam abundance, averaged 30 000 m super(-2) in 1985 and progressively declined to zero in 1990. Combined data from all eight pools showed a significant decline in abundance of fingernail clams. An evaluation of potential causal factors led us to hypothesize that the population declines in Pools 2 to 9 were linked to point-source pollution rather than to dredging activity or commercial navigation traffic. In Pool 19, the declines of fingernail clams may have resulted from low-flow conditions during drought periods, but the causal mechanisms by which low flow influences fingernail clam abundance are unclear. The decrease in fingernail clam populations may adversely affect certain fish and wildlife, such as migrating lesser scaup Aythya affinis, which feed heavily on the small mollusk. Moreover, the decreases in populations of this pollution-sensitive mollusk may signal a large-scale deterioration in the health of this riverine ecosystem.

  16. White Dwarf Stars

    NASA Astrophysics Data System (ADS)

    Kepler, S. O.

    2014-10-01

    White dwarfs are the evolutionary endpoint for nearly 95% of all stars born in our Galaxy, the final stages of evolution of all low- and intermediate mass stars, i.e., main sequence stars with masses below (8.5± 1.5) M_{odot}, depending on metallicity of the progenitor, mass loss and core overshoot. Massive white dwarfs are intrinsically rare objects, tand produce a gap in the determination of the initial vs. final mass relation at the high mass end (e.g. Weidemann 2000 A&A, 363, 647; Kalirai et al. 2008, ApJ, 676, 594; Williams, Bolte & Koester 2009, ApJ, 693, 355). Main sequences stars with higher masses will explode as SNII (Smartt S. 2009 ARA&A, 47, 63), but the limit does depend on the metallicity of the progenitor. Massive white dwarfs are probably SNIa progenitors through accretion or merger. They are rare, being the final product of massive stars (less common) and have smaller radius (less luminous). Kepler et al. 2007 (MNRAS, 375, 1315), Kleinman et al. 2013 (ApJS, 204, 5) estimate only 1-2% white dwarfs have masses above 1 M_{odot}. The final stages of evolution after helium burning are a race between core growth and loss of the H-rich envelope in a stellar wind. When the burning shell is exposed, the star rapidly cools and burning ceases, leaving a white dwarf. As they cool down, the magnetic field freezes in, ranging from a few kilogauss to a gigagauss. Peculiar type Ia SN 2006gz, SN 2007if, SN 2009dc, SN 2003fg suggest progenitors in the range 2.4-2.8 M_{odot}, and Das U. & Mukhopadhyay B. (2012, Phys. Rev. D, 86, 042001) estimate that the Chandrasekhar limit increases to 2.3-2.6 M_{odot} for extremely high magnetic field stars, but differential rotation induced by accretion could also increase it, according to Hachisu I. et al. 2012 (ApJ, 744, 69). García-Berro et al. 2012, ApJ, 749, 25, for example, proposes double degenerate mergers are the progenitors of high-field magnetic white dwarfs. We propose magnetic fields enhance the line broadening in

  17. Biodeposition, respiration, and excretion rates of an introduced clam Mercenaria mercenaria in ponds with implications for potential competition with the native clam Meretrix meretrix in Shuangtaizi estuary, China

    NASA Astrophysics Data System (ADS)

    Zhang, Anguo; Yuan, Xiutang; Hou, Wenjiu; Li, Xiaodong; Zhao, Kai; Chen, Weixin; Su, Xiurong

    2016-05-01

    This study aimed to evaluate the potential impacts of an introduced clam Mercenaria mercenaria on estuarine ecosystem, and implications for the niche competition with a native clam Meretrix meretrix. The biodeposition, respiration, and excretion rates of M. mercenaria were determined seasonally using a sediment trap and a closed respirator in field. The biodeposition rates of M. mercenaria were 0.06-0.37 g/ (ind.·d), and the respiration rates were 0.31-14.66 mg/(ind.·d). The ammonia and phosphate excretion rates were 0.18-36.70 and 1.44-14.87 μg/(ind.·d), respectively. The hard clam M. mercenaria may discharge dry deposits up to 2.1×105 t, contribute 18.3 t ammonia and 9.0 t phosphate to culture ponds, and consume 7.9×103 t O2 from ponds annually. It suggested that the hard clam M. mercenaria might play an important role in pelagic-benthic coupling in pond ecosystem through biodeposition and excretion. A comparison of the key physiological parameters of the introduced clam M. mercenaria and the native clam Meretrix meretrix suggested that M. mercenaria had a niche similar to that of Meretrix meretrix in Shuangtaizi estuary and might have a potential competition with Meretrix meretrix for habitat and food if M. mercenaria species escaped from the culture pond or artificially released in estuarine ecosystem.

  18. Environmental cadmium exposure impacts physiological responses in Manila clams.

    PubMed

    Zhao, Liqiang; Zhang, Yu; Liang, Jian; Xu, Xian; Wang, Hua; Yang, Feng; Yan, Xiwu

    2014-06-01

    The physiological responses of marine bivalves to chronic cadmium (Cd) exposure at sub-lethal concentrations have been well documented. As of now, few studies have examined the effect of Cd exposure and subsequent recovery period at environmentally realistic concentrations. In this study, environmentally, Cd exposures were performed to assess the physiological responses of the Manila clam Ruditapes philippinarum. The clams were exposed to waterborne Cd at two environmentally realistic concentrations (4 and 40 μg L(-1)) for 35 days and then allowed to recover for another 35 days. The accumulation and elimination of Cd in R. philippinarum were tissue-specific and dose- and time-dependent. Cd accumulation increased sharply in the digestive gland, and Cd elimination was rapid in the gill. Major physiological responses, including clearance rate, absorption efficiency, respiration rate, excretion rate, oxygen to nitrogen ratio, and scope for growth, were significantly affected by Cd exposure. Yet, the clams exposed to 4-μg L(-1) Cd were able to quickly recover their normal physiological processes and clearly exhibited catch-up growth once they were transferred to clean seawater. Hence, R. philippinarum can exhibit good physiological plasticity when confronted with moderately environmental Cd exposure. All physiological responses measured exhibited a highly significant and generally predictable correlation with tissue Cd concentration, which in turn, reflected environmentally realistic exposure conditions. Our results further confirm that the measurement of physiological responses is a sensitive method for assessing stress at environmentally realistic metal concentrations. PMID:24771311

  19. Solar winds surfs waves in the Sun's atmosphere!

    NASA Astrophysics Data System (ADS)

    1999-06-01

    opposite ends after threading it through an object, like a ring. If one person wiggles the string rapidly up and down, waves form in the string that move toward the person at the other end. The ring will "surf" these waves and move toward the other person as well. Try it! "Even with this major discovery, there are questions left to answer. The observations have made it abundantly clear that heavy particles like oxygen 'surf' on the waves, and there is also mounting evidence that waves are responsible for accelerating the hydrogen atoms, the most common constituent of the solar wind. Future observations are needed to establish this fact. Many other kinds of particles, such as helium (second most common) have never been observed in the accelerating part of the corona, and new observations are also needed to refine our understanding of how the waves interact with the solar wind as a whole," said Dr. Steven Cranmer of the Harvard-Smithsonian Center for Astrophysics, lead author of the research to be published in the Astrophysical Journal*. Nevertheless, SOHO has again been able to reveal another of the Sun's mysteries: "This is another triumph for SOHO, stealing a long-held secret from our Sun", said Dr Martin Huber, Head of ESA Space Science Department and co-investigator for UVCS. *Ref. Article by S.Cranmer, G.B. Field and J.L. Kohl on Astrophysical Journal ( June 20, Vol 518, p. 937-947) available on the web at: http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v518n2/39802/sc0.html

  20. Solar winds surfs waves in the Sun's atmosphere!

    NASA Astrophysics Data System (ADS)

    1999-07-01

    opposite ends after threading it through an object, like a ring. If one person wiggles the string rapidly up and down, waves form in the string that move toward the person at the other end. The ring will "surf" these waves and move toward the other person as well. Try it! "Even with this major discovery, there are questions left to answer. The observations have made it abundantly clear that heavy particles like oxygen 'surf' on the waves, and there is also mounting evidence that waves are responsible for accelerating the hydrogen atoms, the most common constituent of the solar wind. Future observations are needed to establish this fact. Many other kinds of particles, such as helium (second most common) have never been observed in the accelerating part of the corona, and new observations are also needed to refine our understanding of how the waves interact with the solar wind as a whole," said Dr. Steven Cranmer of the Harvard-Smithsonian Center for Astrophysics, lead author of the research to be published in the Astrophysical Journal*. Nevertheless, SOHO has again been able to reveal another of the Sun's mysteries: "This is another triumph for SOHO, stealing a long-held secret from our Sun", said Dr Martin Huber, Head of ESA Space Science Department and co-investigator for UVCS. *Ref. Article by S.Cranmer, G.B. Field and J.L. Kohl on Astrophysical Journal ( June 20, Vol 518, p. 937-947) available on the web at: http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v518n2/39802/sc0.html

  1. Cluster of Leptospirosis Acquired Through River Surfing in Switzerland.

    PubMed

    Schreiber, Peter W; Aceto, Leonardo; Korach, Raphael; Marreros, Nelson; Ryser-Degiorgis, Marie-Pierre; Günthard, Huldrych F

    2015-09-01

    Background.  In Switzerland, leptospirosis is still considered as a travel-associated disease. After the surprising diagnosis of leptospirosis in a patient who was initially suspected as having primary human immunodeficiency virus infection, we recognized that acquisition of leptospirosis occurred through recreational activities and we identified additional affected individuals. Methods.  Detailed anamnesis, excluding occupational exposure, acquisition abroad, and pet contacts, enabled us to detect the source of infection and identify a cluster of leptospirosis. Convalescent sera testing was performed to confirm Leptospira infection. Microscopic agglutination tests were used to determine the infecting serovar. Results.  We identified a cluster of leptospirosis in young, previously healthy persons. Acquisition of leptospirosis was traced back to a surfing spot on a river in Switzerland (Reuss, Aargau). Clinical presentation was indistinct. Two of the 3 reported cases required hospitalization, and 1 case even suffered from meningitis. Serologic tests indicated infection with the serovar Grippotyphosa in all cases. With the exception of the case with meningitis, no antibiotics were administered, because leptospirosis was diagnosed after spontaneous resolution of most symptoms. Despite a prolonged period of convalescence in 2 cases, full recovery was achieved. Recent reports on beavers suffering from leptospirosis in this region underline the possible water-borne infection of the 3 cases and raise the question of potential wildlife reservoirs. Conclusions.  Insufficient awareness of caregivers, which may be promoted by the missing obligation to report human leptospirosis, combined with the multifaceted presentation of the disease result in significant underdiagnosis. More frequent consideration of leptospirosis as differential diagnosis is inevitable, particularly as veterinary data suggest re-emergence of the disease. PMID:26269796

  2. Cluster of Leptospirosis Acquired Through River Surfing in Switzerland

    PubMed Central

    Schreiber, Peter W.; Aceto, Leonardo; Korach, Raphael; Marreros, Nelson; Ryser-Degiorgis, Marie-Pierre; Günthard, Huldrych F.

    2015-01-01

    Background. In Switzerland, leptospirosis is still considered as a travel-associated disease. After the surprising diagnosis of leptospirosis in a patient who was initially suspected as having primary human immunodeficiency virus infection, we recognized that acquisition of leptospirosis occurred through recreational activities and we identified additional affected individuals. Methods. Detailed anamnesis, excluding occupational exposure, acquisition abroad, and pet contacts, enabled us to detect the source of infection and identify a cluster of leptospirosis. Convalescent sera testing was performed to confirm Leptospira infection. Microscopic agglutination tests were used to determine the infecting serovar. Results. We identified a cluster of leptospirosis in young, previously healthy persons. Acquisition of leptospirosis was traced back to a surfing spot on a river in Switzerland (Reuss, Aargau). Clinical presentation was indistinct. Two of the 3 reported cases required hospitalization, and 1 case even suffered from meningitis. Serologic tests indicated infection with the serovar Grippotyphosa in all cases. With the exception of the case with meningitis, no antibiotics were administered, because leptospirosis was diagnosed after spontaneous resolution of most symptoms. Despite a prolonged period of convalescence in 2 cases, full recovery was achieved. Recent reports on beavers suffering from leptospirosis in this region underline the possible water-borne infection of the 3 cases and raise the question of potential wildlife reservoirs. Conclusions. Insufficient awareness of caregivers, which may be promoted by the missing obligation to report human leptospirosis, combined with the multifaceted presentation of the disease result in significant underdiagnosis. More frequent consideration of leptospirosis as differential diagnosis is inevitable, particularly as veterinary data suggest re-emergence of the disease. PMID:26269796

  3. Predicting coexistence and predominance patterns between the introduced Manila clam (Ruditapes philippinarum) and the European native clam (Ruditapes decussatus)

    NASA Astrophysics Data System (ADS)

    Bidegain, Gorka; Bárcena, Javier Francisco; García, Andrés; Juanes, José Antonio

    2015-01-01

    In several European estuaries, the introduced Manila clam (Ruditapes philippinarum) has become a widespread and predominating species supplanting the native carpet shell clam (Ruditapes decussatus) whereas in other estuaries such as the Bay of Santander (Gulf of Biscay) this pattern has not been detected. Using this estuary as a case study, the potential coexistence/predominance patterns between these two species were explored with the objective of providing insight into the capacity of expansion of R. philippinarum. Firstly, the Ecological Niche Factor Analysis (ENFA) was applied to determine the niches of both species, using seven contemporary environmental variables, i.e. salinity, water depth, current velocity, and sediment sand, gravel, silt and organic matter content. Secondly, ENFA-derived habitat-suitability (HS) maps were simultaneously treated, using geospatial techniques and following HS index-based criteria, to determine the potential distribution patterns. Both species models performed well according to the cross-validation evaluation method. The environmental variables that most determined the presence of both clams were depth, current velocity and salinity. ENFA factors showed that R. philippinarum habitat differs more from the mean environmental conditions over the estuary (i.e. higher marginality) and has less narrow requirements (i.e. lower specialization). R. philippinarum dominated areas, determined by relatively lower current velocities and percentages of sand, higher organic matter contents and slightly shallower depths, were very reduced (i.e. 2.0% of the bay surface) compared to coexistence (47%) and R. decussatus predominance areas (7.4%). These results suggest that HS may regulate the expansion of R. philippinarum. ENFA, together with geospatial analysis of HS index, seems to be a valuable approach to explore the expansion potential of estuarine invasive or introduced species and thus support conservation decisions regarding native species.

  4. Calibrating brown dwarf ages using white dwarfs in wide binaries

    NASA Astrophysics Data System (ADS)

    Catalán, S.

    Even though age is a critical parameter for all objects, it can also be one of the most difficult to measure, in particular for low-mass stars and brown dwarfs. Brown dwarf models suffer from degeneracy and are not useful to infer ages without well constrained atmospheric parameters \\citep{pin06}. However, there is a way to overcome this problem by studying brown dwarfs for which some external constraints are available, for example brown dwarfs in wide binary systems. Wide binary members share proper motion and are supposed to have been born simultaneously and with the same chemical composition. Since they are well separated (⪆ 1000 AU) we can assume that no interaction has occurred between them in the past and they have evolved as isolated objects. If the companion of the brown dwarfs is a white dwarf, we can use it to calibrate the age of the system. White dwarf evolution can be described as a cooling process which is relatively well understood \\citep[e.g.][]{sal00}. Thus, they yield robust age constraints from the use of cooling sequences \\citep{gar11}. White dwarf cooling ages will uniformally give age lower limits (despite some uncertainty on progenitor life-time), and in some cases yield ages to better than 10% accuracy. Hence, wide binary systems containing a white dwarf can have system age constraints inferred from the white dwarf component. There are not many white dwarf-brown dwarf systems known so far, but with the combination of optical and IR surveys, SDSS+UKIDSS and Gaia + UKIDSS/VHS, new systems will be detected.

  5. A Novel Image Retrieval Based on Visual Words Integration of SIFT and SURF

    PubMed Central

    Ali, Nouman; Bajwa, Khalid Bashir; Sablatnig, Robert; Chatzichristofis, Savvas A.; Iqbal, Zeshan; Rashid, Muhammad; Habib, Hafiz Adnan

    2016-01-01

    With the recent evolution of technology, the number of image archives has increased exponentially. In Content-Based Image Retrieval (CBIR), high-level visual information is represented in the form of low-level features. The semantic gap between the low-level features and the high-level image concepts is an open research problem. In this paper, we present a novel visual words integration of Scale Invariant Feature Transform (SIFT) and Speeded-Up Robust Features (SURF). The two local features representations are selected for image retrieval because SIFT is more robust to the change in scale and rotation, while SURF is robust to changes in illumination. The visual words integration of SIFT and SURF adds the robustness of both features to image retrieval. The qualitative and quantitative comparisons conducted on Corel-1000, Corel-1500, Corel-2000, Oliva and Torralba and Ground Truth image benchmarks demonstrate the effectiveness of the proposed visual words integration. PMID:27315101

  6. An improved image matching algorithm based on SURF and Delaunay TIN

    NASA Astrophysics Data System (ADS)

    Cheng, Yuan-ming; Cheng, Peng-gen; Chen, Xiao-yong; Zheng, Shou-zhu

    2015-12-01

    Image matching is one of the key technologies in the image processing. In order to increase its efficiency and precision, a new method for image matching which based on the improved SURF and Delaunay-TIN is proposed in this paper. Based on the original SURF algorithm, three constraint conditions, color invariant model, Delaunay-TIN, triangle similarity function and photography invariant are added into the original SURF model. With the proposed algorithm, the image color information is effectively retained and the erroneous matching rate of features is largely reduced. The experimental results shows that this proposed method has the characteristics of higher matching speed, uniform distribution of feature points to be matched, and higher correct matching rate than the original algorithm does.

  7. A Novel Image Retrieval Based on Visual Words Integration of SIFT and SURF.

    PubMed

    Ali, Nouman; Bajwa, Khalid Bashir; Sablatnig, Robert; Chatzichristofis, Savvas A; Iqbal, Zeshan; Rashid, Muhammad; Habib, Hafiz Adnan

    2016-01-01

    With the recent evolution of technology, the number of image archives has increased exponentially. In Content-Based Image Retrieval (CBIR), high-level visual information is represented in the form of low-level features. The semantic gap between the low-level features and the high-level image concepts is an open research problem. In this paper, we present a novel visual words integration of Scale Invariant Feature Transform (SIFT) and Speeded-Up Robust Features (SURF). The two local features representations are selected for image retrieval because SIFT is more robust to the change in scale and rotation, while SURF is robust to changes in illumination. The visual words integration of SIFT and SURF adds the robustness of both features to image retrieval. The qualitative and quantitative comparisons conducted on Corel-1000, Corel-1500, Corel-2000, Oliva and Torralba and Ground Truth image benchmarks demonstrate the effectiveness of the proposed visual words integration. PMID:27315101

  8. Surfing in tortoises? Empirical signs of genetic structuring owing to range expansion

    PubMed Central

    Graciá, Eva; Botella, Francisco; Anadón, José Daniel; Edelaar, Pim; Harris, D. James; Giménez, Andrés

    2013-01-01

    Much of our current knowledge about the genetic dynamics in range expansions originates from models, simulations and microcosm experiments that need to be corroborated by field data. Here, we report a neutral genetic pattern that matches the predictions of the genetic surfing theory. Genetic surfing occurs when repeated founding events and genetic drift act on the wave of advance of an expanding population, promoting strong spatial structure. In the range expansion of the tortoise Testudo graeca from North Africa to southeastern Spain, we found several genetic signatures consistent with surfing: a decrease of genetic diversity with distance from the initial founder area, clinal patterns in allele frequencies, rare African alleles which have become common at distal sites in the Spanish range, and stronger spatial differentiation in the expanded range than in the original one. Our results provide support for the theory that genetic drift can be an important force in shaping the genetic structure of expanding populations. PMID:23554278

  9. Experimental evaluation of the pathogenicity of Perkinsus olseni in juvenile Manila clams Ruditapes philippinarum.

    PubMed

    Shimokawa, Jun; Yoshinaga, Tomoyoshi; Ogawa, Kazuo

    2010-11-01

    We evaluated the pathogenicity of Perkinsus olseni towards the Manila clam, Ruditapes philippinarum, by an experimental challenge. For production of prezoosporangia of P. olseni, we injected uninfected Manila clams with cells of a pure strain of P. olseni and reared them for 7d. Prezoosporangia were isolated from the soft tissue of the injected clams after culturing in Ray's fluid thioglycollate medium. Hatchery-reared, uninfected juvenile clams (3-10 mm shell length) were challenged by immersion in one of two concentrations of a prezoosporangial suspension of P. olseni for 6d. The challenged clams had significantly higher mortality at both the concentrations than the unchallenged clams. The mortality due to infection dose-dependently began approximately 4 weeks and 7 weeks after challenge in the higher and lower concentrations, respectively. This is the first experimental evidence that P. olseni causes direct mortality in Manila clams. The lethal level of infection was estimated at approximately 10⁷ pathogen cells/g soft tissue weight. PMID:20807538

  10. [Case of food protein-induced enterocolitis syndrome caused by short-neck clam ingestion].

    PubMed

    Hayashi, Daisuke; Aoki, Takeshi; Shibata, Rumiko; Ichikawa, Kunio

    2010-12-01

    A 6-year-old boy was referred for evaluation because he had several vomiting episodes, from the age of 2 years, following short-neck clam ingestion. He tested negative for short-neck clam-specific IgE just before visiting our hospital, and he was not allergic to other foods or shellfish. The patient had low levels of short-neck clam-specific IgE (1.04 UA/ml), and the skin prick test was positive for short-neck clam (4 mm). The lymphocyte stimulation test was positive (5305 counts per min (cpm), stimulation index (SI) =1211%) and the patch test was positive for short-neck clam ingestion. An oral challenge test with boiled short-neck clam induced abdominal pain and vomiting 2 h after ingestion, and the patient presented with increased peripheral leukocytes after 6 h. He was therefore diagnosed with food protein-induced enterocolitis syndrome (FPIES) due to short-neck clam ingestion. To our knowledge, this is the first case report of FPIES induced by the intake of shellfish. PMID:21212729

  11. Great Lakes clams find refuge from zebra mussels in restored, lake-connected marsh (Ohio)

    USGS Publications Warehouse

    Nichols, S. Jerrine; Wilcox, Douglas A.

    2004-01-01

    Since the early 1990s, more than 95 percent of the freshwater clams once found in Lake Erie have died due to the exotic zebara mussel (Dreissena polymorpha). Zebra mussels attach themselves to native clams in large numbers, impeding the ability of the clams to eat and burrow. However, in 1996, we discovered a population of native clams in Metzger Marsh in western Lake Erie (about 50 miles [80 km] east of Toledo) that were thriving despite the longtime presence of zebra mussel in surrounding waters. At that time, Metzger Marsh was undergoing extensive restoration, including construction of a dike to replace the eroded barrier beach and of a water-control structure to maintain hydrologic connections with the lake (Wilcox and Whillans 1999). The restoration plan called for a drawdown of water levels to promote plant growth from the seedbank -- a process that would also destroy most of the clam population. State and federal resource managers recommended removing as many clams as possible to a site that was isolated from zebra mussels, and then returning them to the marsh after it was restored. We removed about 7,000 native clams in 1996 and moved them back to Metzger Marsh in 1999.

  12. Bacciger bacciger (Trematoda: Fellodistomidae) infection effects on wedge clam Donax trunculus condition.

    PubMed

    de Montaudouin, Xavier; Bazairi, Hocein; Mlik, Karima Ait; Gonzalez, Patrice

    2014-10-16

    Wedge clams Donax trunculus inhabit high-energy environments along sandy coasts of the northeastern Atlantic Ocean and the Mediterranean Sea. Two sites were sampled monthly, one in Morocco (Mehdia), where the density was normal, and one in France (Biscarosse), where the density was very low. We tested the hypothesis that the difference in density between the sites was related to infection by the trematode parasite Bacciger bacciger. Identity of both the parasite and the host were verified using anatomical and molecular criteria. Parasite prevalence (i.e. the percentage of parasitized clams) was almost 3 times higher at Biscarosse. At this site, overall prevalence reached 32% in July and was correlated with the migration of several individuals (with a prevalence of 88%) to the sediment surface. After this peak, prevalence decreased rapidly, suggesting death of parasitized clams. The deleterious effect of B. bacciger on wedge clams was also supported by our calculations indicating that the weight of the parasite made up to 56% of the total weight of the parasitized clams. However, condition indices of trematode-free clams were also lower in Biscarosse than in Mehdia or other sites, suggesting that other factors such as pollutants or microparasites (Microcytos sp.) may alter wedge clam population fitness in Biscarosse. PMID:25320038

  13. Recovery of intertidal hardshelled clams in Prince William Sound from Exxon Valdez oiling and shoreline treatments

    SciTech Connect

    Houghton, J.P.; Lees, D.C.; Driskell, W.B.

    1994-12-31

    Native little neck (Protothaca staminea) and butter clams (Saxidomus giganteus) were quantitatively surveyed from 1989 through 1993 to evaluate effects from the Exxon Valdez oil spill. Hydraulic washing of sand and gravel beaches altered beach morphology by transporting material down slope from upper elevations, often burying the lower beach in several centimeters of sediment having a relatively low content of fines and organic carbon. Hydraulically washed beaches showed significant reductions in clam densities in 1989 and 1990. Recruitment of clams was very limited on these beaches through 1993; as a result, clam densities on these hydraulically washed beaches remain very depressed compared to those on beaches that were unoiled or oiled but not washed. Littlenecks transplanted from a reference site to a heavily oiled but untreated site showed significant patterns of increased mortality, decreased growth, and increased bioaccumulation of PAH in response to a gradient in sediment PAH, This same heavily oiled site has consistently had among the highest rates of hardshelled clam recruitment of any of the sites sampled. Littlenecks also were transplanted to another heavily oiled beach that had been hydraulically washed and had little remaining hydrocarbons. These clams showed very high survival, yet this beach has had very little clam recruitment. It is hypothesized that recruitment at this site may be inhibited by the low level of finer sediments and low organic content remaining after washing.

  14. Early reproductive success of the hard clam (Mercenaria mercenaria) from Five Sites in Long Island Sound

    SciTech Connect

    Stiles, S.; Choromanski, J.; Nelson, D.; Miller, J.; Greig, R.; Sennefelder, G. )

    1991-09-01

    Early reproductive success of hard clams (Mercenaria mercenaria) in Long Island Sound was measured to determine whether pollution may have adverse effects on fragile recruitment to fisheries. Clams were collected at five sites in 1987 when ready to spawn naturally, along with water from within 39 cm of the bottom. Levels of polychlorinated biphenyls (PCBs), copper, and cadmium were measured in the mature gonad and were found to be generally low. Clams were spawned and the gametes were collected and cultured both in their respective site waters and in reference laboratory seawater. In both site and reference seawater, embryos of clams from the most highly industrialized area (Bridgeport) with higher contaminant levels exhibited more irregularity in chromosome numbers and greater larval abnormality, possible indicators of long-term sublethal effects. Fertilization and early meiotic success at 1 to 1 1/2 h were significantly lower for clams from Norwalk than for those from Greenwich. At 48 h, mortality was lowest for Greenwich larvae and highest for Norwalk larvae in their respective site waters, but the mortality for these two sites was significantly lower than for other sites in reference water. This suggests sporadically poor environmental quality. Milford larvae also had significant mortality. Population-level significance of pollution effects on clam reproduction will depend on how contaminated the environment is over the entire reproductive season of the clams in Long Island Sound, and over how large a portion of the spawning grounds.

  15. Depuration kinetics of hepatitis A virus in clams.

    PubMed

    Polo, David; Ávarez, Cristina; Vilariño, M Luz; Longa, Ángeles; Romalde, Jesús L

    2014-05-01

    The efficacy and dynamic of depuration for the removal of hepatitis A virus (HAV) contamination were evaluated under experimental conditions using Manila clams previously subjected to bioaccumulation with this virus. Five independent trials were assayed in a closed experimental system with a total volume of approximately 1750 l, using clam batches of 60 Kg. The reverse transcriptase-real time PCR (RT-qPCR) technique was utilized for viral quantification. Infectivity assays were conducted at the end of depuration. Although the final viral loads in shellfish after 7 days remained relatively high and still infectious, an average reduction in HAV levels of 1.44 log units (approx. 93.1%) was observed. This reduction showed a two-phase removal kinetic, with an initial rapid reduction of viruses during the first 72 h of depuration, with a 0.6 log units (69%) of average decrease in HAV RNA copies/g digestive tissue, and a subsequent stabilization with a slower depuration rate in the remaining days. PMID:24387859

  16. Effects of permethrin on biomarkers in Mediterranean clams (Ruditapes decussatus).

    PubMed

    Sellami, B; Khazri, A; Louati, H; Boufahja, F; Dellali, M; Sheehan, D; Aissa, P; Driss, M Ridha; Mahmoudi, E; Beyrem, H

    2014-05-01

    The present study was focused on the assessment of Catalase (CAT) and Acetylcholinesterase (AChE) activities in Mediterranean clams (Ruditapes decussatus) exposed to 50, 100 and 150 μg/L of Permethrin for 5, 10, 15, 20 and 25 days. In water, the measured concentrations of Permethrin in the treated aquariums were respectively 16.66, 38.24 and 55.61 μg/L. Results showed that CAT activity was increased after 5 days of exposure to high concentration reaching maximum value of 10.14 μmol/min/mg proteins after 25 days. However, no significant changes in AChE activity after 5 days of exposure were detected in all treated groups. AChE activity was significantly inhibited after 10 days with 100 and 150 μg/L and still depending on concentration and time. Maximum inhibition of AChE activity was reached after 25 days with the highest concentration of Permethrin. Our data indicated that exposure to Permethrin modifies biomarker profiles inducing oxidative stress and reducing AChE activity in Mediterranean clams. PMID:24519478

  17. SURF: Taking Sustainable Remediation from Concept to Standard Operating Procedure (Invited)

    NASA Astrophysics Data System (ADS)

    Smith, L. M.; Wice, R. B.; Torrens, J.

    2013-12-01

    Over the last decade, many sectors of industrialized society have been rethinking behavior and re-engineering practices to reduce consumption of energy and natural resources. During this time, green and sustainable remediation (GSR) has evolved from conceptual discussions to standard operating procedure for many environmental remediation practitioners. Government agencies and private sector entities have incorporated GSR metrics into their performance criteria and contracting documents. One of the early think tanks for the development of GSR was the Sustainable Remediation Forum (SURF). SURF brings together representatives of government, industry, consultancy, and academia to parse the means and ends of incorporating societal and economic considerations into environmental cleanup projects. Faced with decades-old treatment programs with high energy outputs and no endpoints in sight, a small group of individuals published the institutional knowledge gathered in two years of ad hoc meetings into a 2009 White Paper on sustainable remediation drivers, practices, objectives, and case studies. Since then, SURF has expanded on those introductory topics, publishing its Framework for Integrating Sustainability into Remediation Projects, Guidance for Performing Footprint Analyses and Life-Cycle Assessments for the Remediation Industry, a compendium of metrics, and a call to improve the integration of land remediation and reuse. SURF's research and members have also been instrumental in the development of additional guidance through ASTM International and the Interstate Technology and Regulatory Council. SURF's current efforts focus on water reuse, the international perspective on GSR (continuing the conversations that were the basis of SURF's December 2012 meeting at the National Academy of Sciences in Washington, DC), and ways to capture and evaluate the societal benefits of site remediation. SURF also promotes and supports student chapters at universities across the US

  18. Registration of cardiac magnetic resonance images using SURF points and matching

    NASA Astrophysics Data System (ADS)

    Moreno, Braian; Atehortúa, Angélica; Corredor, Germán.; Romero, Eduardo

    2015-01-01

    Reconstruction of the heartbeat is an useful tool to detect and diagnose some pathologies. However, this process represents a challenge because the heart is a moving organ inside a moving body, so that, either similar regions are hard to identify or some regions appear and disappear constantly. This article presents a reconstruction method of the right ventricle using SURF points in irregular regions. The SURF points, invariant to image scale and rotation, provide robust features of a right ventricle slice that can then be traced to the other slices. By using such points and then, using a nonrigid registration, it possible to perform a volumetrical reconstruction of these images.

  19. Solidification of carbon-oxygen white dwarfs

    NASA Technical Reports Server (NTRS)

    Schatzman, E.

    1982-01-01

    The internal structure of white dwarfs is discussed. Highly correlated plasmas are reviewed. Implications for phase separation in the core of cooling white dwarfs are considered. The consequences for evolution of white dwarfs are addressed.

  20. Distribution and winter survival health of Asian clams, Corbicula fluminea, in the St. Clair River, Michigan

    USGS Publications Warehouse

    French, John R. P., III; Schloesser, Don W.

    1996-01-01

    We studied the distribution and winter survival of the Asian clam, Corbicula fluminea, in the St. Clair River from the fall of 1988 to the spring of 1990. Between fall of 1988 and spring of 1989, distribution of Corbicula was extended from 5.5 to 11.5 km downstream from an electric power plant. However, total abundance of clams decreased during the winter. By fall of 1989, Corbicula was found 14.5 km from the power plant, and the mean density of clams was 27 individuals/m2. Between fall of 1989 and spring of 1990, distribution was reduced to 7.5 km from the power plant and abundance decreased 97%. During the winter of 1988-1989, we collected clams monthly from one station 2.2 km from the power plant, and we observed that clams survived the harsh winter for two months after the water temperature dropped about 1.5°C below the reported lethal level for Corbicula in midwinter. During the winer of 1989-1990, we held clams at the sediment-water interface in enclosures, and we observed that condition indices (dry body weight; dry shell weight) of clams remained stable (mean = 0.05 ± 0.01) in December and January and then declined significantly (p < 0.05) to 0.04 ± 0.01 in February. All clams perished by late March. The deteriorating physiological state of clams, as indicated by declining condition index, seemingly is a factor in late winter mortalities of Corbicula in the St. Clair River. In contrast to the rapid geographic spread and population increases in the southern United States, Corbicula likely will not spread rapidly throughout the Great Lakes beyond shoreline thermal refugia of heated-water discharge plumes from power plants.

  1. [Identification of the protein partners of the human nucleolar protein SURF6 in HeLa cells by GST pull-down assay].

    PubMed

    Kordiukova, M Iu; Polzikov, M A; Shishova, K V; Zatsepina, O V

    2014-01-01

    The eukaryotic proteins comprising the SURF6 protein family are evolutionary conservative and housekeeping proteins however, functional roles of human SURF6 have not been studied so far. To shed light to this question in the present work we applied GST pull-down assay and used two proteins fused with GST, namely human GST-SURF6 and the conservative C-terminal domain of mouse Surf6 that has 85% homology with the C-terminus of the human SURF6 conservative domain (GST-Surf6-dom), to identify SURF6-interacting proteins in human HeLa cells. The results obtained showed that GST-SURF6 interacts with several key nucleolar RNA processing factors (B23/nucleophosmin, nucleolin, EBP2), and also with the specific cofactor of RNA polymerase I, protein UBE These results are the first experimental evidences in favor of participation of the human SURF6 protein in ribosome biogenesis, including transcription of rDNA and processing of rRNAs. The same results were obtained, when GST-Surf6-dom was used to pull-down proteins in HeLa cells. In addition, the panel of the GST-Surf6-dom protein partners, which were identified by mass-spectrometry, points to putative interactions of human SURF6 with a number of nuclear and nucleolar, proteins of other functional groups, i.e. to the protein plurifunctionality. PMID:25898752

  2. Local Universe Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Carignan, Claude

    2015-08-01

    One of the outstanding problems in cosmology is addressing the "small-scale crisis" and understanding structure formation at the smallest scales. Standard Lambda Cold Dark Matter cosmological simulations of Milky Way-size DM halos predict many more DM sub-halos than the number of dwarf galaxies observed. This is the so-called Missing Satellites Problem. The most popular interpretation of the Missing Satellites Problem is that the smallest dark matter halos in the universe are extremely inefficient at forming stars. The virialized extent of the Milky Way's halo should contain ~500 satellites, while only ˜100 satellites and dwarfs are observed in the whole Local Group. Despite the large amount of theoretical work and new optical observations, the discrepancy, even if reduced, still persists between observations and hierarchical models, regardless of the model parameters. It may be possible to find those isolated ultra-faint missing dwarf galaxies via their neutral gas component, which is one of the goals we are pursuing with the SKA precursor KAT-7 in South Africa, and soon with the SKA pathfinder MeerKAT.

  3. Distances to WISE Y dwarfs

    NASA Astrophysics Data System (ADS)

    Beichman; A., C.; Gelino; R., C.; Kirkpatrick, J. Davy

    The WISE satellite has detected some of the coldest, lowest mass objects in the solar neighborhood. These late T and early Y dwarfs have effective temperatures in the range 250-800 K and inferred masses in the range 5-25 MJup. A critical piece of information for determining the physical properties of a brown dwarf is its distance, which greatly improves the comparison with evolutionary models. We discuss the importance of Y dwarfs in the context of star and planet formation. We also update our recent paper on Y dwarf parallaxes with improved values for four objects based on recent observations.

  4. The asiatic clam, Corbicula fluminea (Müller), in the tidal Potomac River, Maryland

    USGS Publications Warehouse

    Dresler, Paul V.; Cory, Robert L.

    1980-01-01

    The Asiatic clam,Corbicula fluminea (Müller), has extended its range to include the tidal fresh-water portion of the Potomac River, Maryland. Though patchily distributed, the clams have attained densities of 665 m−2. Size-class distributions indicate that the clams first appeared in 1975. About 90% of the population belong to year-class I and were less than 12 mm in length. Elsewhere, this species has created severe water quality problems; it should be closely watched in the Potomac.

  5. Non-linear control of the ''clam'' wave energy device. Final report

    SciTech Connect

    Not Available

    1983-09-01

    A promising wave energy device being currently investigated is the ''clam'' device. The clam extracts energy by pumping air through a specially designed (Wells) turbine. Although operation of the Wells turbine does not require a rectified air flow, some additional control will be necessary to optimize the phase of the clam motion for good efficiencies. An examination of the equation of motion in the time domain suggests the possibility of non-linear phase control by mechanical, power take-off, or pneumatic latching. Latching can be shown to increase the efficiency of the device in the longer wavelengths of the wave spectrum, i.e. those of high incident wave power.

  6. Field and laboratory transmission studies of haemic neoplasia in the soft-shell clam, Mya arenaria, from Atlantic Canada.

    PubMed

    Mateo, D R; MacCallum, G S; Davidson, J

    2016-08-01

    A two-year laboratory and field study was initiated in 2001 in response to mass mortalities associated with haemic neoplasia (HN) in 1999 in Prince Edward Island (PEI) soft-shell clams, Mya arenaria. A laboratory proximity experiment (cohabitation) and an inoculation challenge were conducted with clams and mussels (Mytilus edulis). Three field exposure experiments were also conducted, in which naive clams were held in sediment (in trays) or out of sediment (in mesh bags) at three high HN prevalence sites on PEI. There was a conversion to HN positive in clams in the proximity experiment and in clams injected with whole blood and cell-free homogenate, but not at statistically significant levels. No mussels or control clams became HN positive. There was a significant conversion to HN positive in as little as 24 and 58 days after transfer with clams held out of sediment and in sediment, respectively. The laboratory and field experiments' results suggest that HN-infected clams are spreading the disease through water from infected clams to naïve individuals and via transplantation from affected to unaffected sites. Some environmental conditions (e.g. abnormally high water temperature and hypoxia-induced sea lettuce [Ulva lacteus] invasion) may make clams susceptible to infections or exacerbate the proliferation of HN. PMID:26687447

  7. 50 CFR 648.73 - Closed areas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Clam and Ocean Quahog Fisheries § 648.73 Closed areas. Link to an amendment published at 76 FR 60623... surf clam and ocean quahog fishing because of adverse environmental conditions. These areas will remain... small surf clams. Areas may be closed because they contain small surf clams. (1) Closure. The...

  8. Satellite dwarf galaxies in a hierarchical universe: the prevalence of dwarf-dwarf major mergers

    SciTech Connect

    Deason, Alis; Wetzel, Andrew; Garrison-Kimmel, Shea

    2014-10-20

    Mergers are a common phenomenon in hierarchical structure formation, especially for massive galaxies and clusters, but their importance for dwarf galaxies in the Local Group remains poorly understood. We investigate the frequency of major mergers between dwarf galaxies in the Local Group using the ELVIS suite of cosmological zoom-in dissipationless simulations of Milky Way- and M31-like host halos. We find that ∼10% of satellite dwarf galaxies with M {sub star} > 10{sup 6} M {sub ☉} that are within the host virial radius experienced a major merger of stellar mass ratio closer than 0.1 since z = 1, with a lower fraction for lower mass dwarf galaxies. Recent merger remnants are biased toward larger radial distance and more recent virial infall times, because most recent mergers occurred shortly before crossing within the virial radius of the host halo. Satellite-satellite mergers also occur within the host halo after virial infall, catalyzed by the large fraction of dwarf galaxies that fell in as part of a group. The merger fraction doubles for dwarf galaxies outside of the host virial radius, so the most distant dwarf galaxies in the Local Group are the most likely to have experienced a recent major merger. We discuss the implications of these results on observable dwarf merger remnants, their star formation histories, the gas content of mergers, and massive black holes in dwarf galaxies.

  9. Toxicological responses to acute mercury exposure for three species of Manila clam Ruditapes philippinarum by NMR-based metabolomics.

    PubMed

    Liu, Xiaoli; Zhang, Linbao; You, Liping; Cong, Ming; Zhao, Jianmin; Wu, Huifeng; Li, Chenghua; Liu, Dongyan; Yu, Junbao

    2011-03-01

    The Manila clam (Ruditapes philippinarum) has been considered a good sentinel species for metal pollution monitoring in estuarine tidal flats. Along the Bohai coast of China, there are dominantly distributed three species of clams (White, Liangdao Red and Zebra in Yantai population) endowed with distinct tolerances to environmental stressors. In this study, adductor muscle samples were collected from both control and acute mercury exposed White, Liangdao Red and Zebra clams, and the extracts were analyzed by NMR-based metabolomics to compare the metabolic profiles and responses to the acute mercury exposure to determine the most sensitive clam species capable of acting as abioindicator for heavy metal pollution monitoring. The major abundant metabolites in the White clam sample were branched-chain amino acids (leucine, isoleucine and valine), lactate, arginine, aspartate, acetylcholine, homarine and ATP/ADP, while the metabolite profile of Zebra clam sample comprised high levels of glutamine, acetoacetate, betaine, taurine and one unidentified metabolite. For the Liangdao Red clam sample, the metabolite profile relatively exhibited high amount of branched-chain amino acids, arginine, glutamate, succinate, acetylcholine, homarine and two unassigned metabolites. After 48h exposure of 20μgL(-1) Hg(2+), the metabolic profiles showed significant differences between three clam species, which included increased lactate, succinate, taurine, acetylcholine, betaine and homarine and decreased alanine, arginine, glutamine, glutamate, acetoacetate, glycine and ATP/ADP in White clam samples, and elevated succinate, taurine and acetylcholine, and declined glutamine, glycine, and aspartate in Liangdao Red clam samples, while the increased branched-chain amino acids, lactate, succinate, acetylcholine and homarine, and reduced alanine, acetoacetate, glycine and taurine were observed in the Zebra clam samples. Overall, our findings showed that White clams could be a preferable

  10. The Evolution of Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Dunn, Jacqueline M.

    2016-01-01

    Dwarf galaxies are the most numerous galaxies in the Universe, yet the driving forces in their evolution remain elusive. The proposed evolutionary link between dwarf irregular and dwarf elliptical/spheroidal galaxies is investigated using broad-band UBVR photometry obtained for a sample of 29 dwarf galaxies. The galaxies span a range of absolute B-band magnitude from -13.67 to -19.86 mag. Broad-band colors and Sérsic surface brightness profile fits are compared for the two morphological types. All optical parameters are statistically different between the two subsamples, as evidenced by the significance level of the Kolmogorov-Smirnov statistic.Others have noted that dwarf ellipticals might have looked much like the currently observed dwarf irregulars in the past based on optical colors. An overlap between in the range of colors observed is noted for these targets, implying the possibility of an evolutionary link. A difference is noted between the two samples in the value of n (the power-law exponent determined from the Sérsic profile fitting), suggesting that the two main types of dwarf galaxy are structurally distinct. The differences in the structure of the stellar components would imply that dwarf irregulars do not evolve to become dwarf ellipticals in isolation, meaning that some sort of external interaction is required if the transformation is to occur. However, when the brightest dwarf elliptical targets are eliminated from the comparison, the two dwarf samples are much more similar in their values and range for the power-law exponent, which again suggests a possible evolutionary link. The environments of the galaxies are initially classified as either field or group/cluster, though no definitive environmental comparison is presented here.

  11. 76 FR 8651 - Special Local Regulation; Mavericks Surf Competition, Half Moon Bay, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ..., Half Moon Bay, CA AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary special local regulation on certain navigable waters of Half Moon Bay in support of... Half Moon Bay. The Mavericks Surf Competition will occur in the vicinity of Pillar Point in...

  12. The Ocean as a Unique Therapeutic Environment: Developing a Surfing Program

    ERIC Educational Resources Information Center

    Clapham, Emily D.; Armitano, Cortney N.; Lamont, Linda S.; Audette, Jennifer G.

    2014-01-01

    Educational aquatic programming offers necessary physical activity opportunities to children with disabilities and the benefits of aquatic activities are more pronounced for children with disabilities than for their able-bodied peers. Similar benefits could potentially be derived from surfing in the ocean. This article describes an adapted surfing…

  13. Access Without Authentication: How and Why We Let Anyone Surf Our Wireless

    ERIC Educational Resources Information Center

    Watkins, Donna

    2006-01-01

    Wireless hotspots are popping up in local coffee shops everywhere. Anyone with a wireless-ready laptop or PDA can surf the Internet at one of these hotspots. The same is now true for all 32 branches of the Orange County Public Library (OCPL) in California. Though many public library systems are moving toward wireless access, most require patrons…

  14. Validation of accuracy and repeatability of UltraSurf metrology on common optical shapes

    NASA Astrophysics Data System (ADS)

    DeFisher, Scott; Matthews, Greg; Fess, Edward

    2015-10-01

    Advancements in optical manufacturing technology allow optical designers to implement steep aspheric or high departure surfaces into their systems. Accurate metrology during the grinding and polishing stages of asphere manufacturing will reduce time and cost. Measuring these surfaces with common interferometers or profilometers can be difficult due to large surface slopes or unpolished surface texture. OptiPro has developed UltraSurf to qualify the form, figure, and thickness of steep aspheric and freeform optics. UltraSurf is a computer controlled, non-contact coordinate measuring machine. It incorporates five air-bearing axes, linear motors, high-resolution feedback, and a non-contact probe. The measuring probe is scanned over the optical surface while maintaining perpendicularity and a constant focal offset. There are multiple probe technologies available on UltraSurf, and each probe has strengths and weaknesses relative to the material properties, surface finish, and figure error of an optical component. Validation of the system accuracy, repeatability, and methodology must be performed to trust the measurement data. Form and figure maps of a flat, a sphere, and an asphere using UltraSurf will be presented with comparisons to interferometry. In addition, accuracy, repeatability, and machine qualification will be discussed.

  15. "Making Waves" with Burke: Surf Nazi Culture and the Rhetoric of Localism.

    ERIC Educational Resources Information Center

    Scheibel, Dean

    1995-01-01

    Describes the historical, cultural, and mythic contexts that infuse the territorial exclusionary practices of surfers. Analyzes surfers' rhetorical responses in letters published in surfing magazines, describing how rhetors use economic and religious metaphors to position ideologies that both reproduce and mediate cultural myths of perfection…

  16. Copper and silver accumulation in transplanted and resident clams (Macoma balthica) in South San Francisco Bay

    USGS Publications Warehouse

    Cain, D.J.; Luoma, S.N.

    1985-01-01

    Accumulation of Cu and Ag by soft tissues of the deposit-feeding clam Macoma balthica was less than half in clams transplanted to a contaminated area than in clams native to that area. During a period of tissue growth, the transplants retained 50% and 90%, respectively, of the net Cu and Ag accumulated, but loss of metals from soft tissue by the resident population equalled net accumulation. Copper accumulation in the transplants did not occur during some periods when increases in the metal body burden of the resident population indicated that environmental exposures were high. The difference in metal accumulation of the two groups of clams may be the result of past environmental exposures. The results illustrate some limitations of using transplants as indicators of pollution events or of pollutant impact upon resident populations.

  17. Assessment of immune parameters of manila clam Ruditapes philippinarum in different physiological conditions using flow cytometry

    NASA Astrophysics Data System (ADS)

    Park, Kyung-Il; Donaghy, Ludovic; Kang, Hyun-Sil; Hong, Hyun-Ki; Kim, Young-Ok; Choi, Kwang-Sik

    2012-03-01

    Cellular and humoral immune parameters are often used as biomarkers to trace environmental and physiological stresses in marine bivalves. In this study, we compared various immune parameters of Manila clams ( Ruditapes philippinarum) under normal conditions and under a high level of desiccation, using flow cytometry. The immune parameters analyzed included, total hemocyte count, hemocyte mortality, hemocyte DNA damage, reactive oxygen species (ROS) production, and phagocytosis activity. Total hemocyte count, hemocyte DNA damage, and hemocyte mortality were significantly elevated among clams under high desiccation stress, while phagocytosis activity and spontaneous ROS production were significantly lower compared to those parameters of the control clams ( p<0.05). These data suggest that the immune parameters analyzed in this study well reflect the physiological status of clams.

  18. Does Manila clam cultivation affect habitats of the engineer species Lanice conchilega (Pallas, 1766)?

    PubMed

    Toupoint, Nicolas; Godet, Laurent; Fournier, Jérôme; Retière, Christian; Olivier, Frédéric

    2008-08-01

    The major French site of Manila clam Ruditapes philippinarum (Adams and Reeves, 1850) cultivation is located in the Chausey Archipelago where the associated practices are highly mechanized: every steps of production are made with tractor-driven machinery. The Manila clam concessions are concentrated on Lanice conchilega (Pallas, 1766) bioherms, which are known to increase alpha-diversity and to locally modify sediment dynamics. This study focus on the impacts of Manila clam cultivation on (i) the natural populations of L. conchilega and on (ii) the structure of the associated benthic assemblages during the different steps of the farming production cycle. We found that the L. conchilega populations are significantly affected within the concessions where their total abundances drastically decrease, their spatial patterns are modified and the associated benthic assemblages are significantly altered. Our results are discussed in a context of a sustainable management of the Manila clam cultivation in coastal areas. PMID:18561956

  19. Kinematics of faint white dwarfs.

    PubMed

    Luyten, W J

    1978-10-01

    An analysis has been made for solar motion for 128 very faint white dwarfs of color class b or a. While about 40% of these stars may be high-velocity objects, it seems definitely indicated that the luminosity of all of them is considerably lower than that for the "normal" white dwarf of the same color. PMID:16592566

  20. Heart Rate Responses of High School Students Participating in Surfing Physical Education.

    PubMed

    Bravo, Michelle M; Cummins, Kevin M; Nessler, Jeff A; Newcomer, Sean C

    2016-06-01

    Bravo, MM, Cummins, KM, Nessler, JA, and Newcomer, SC. Heart rate responses of high school students participating in surfing physical education. J Strength Cond Res 30(6): 1721-1726, 2016-Despite the nation's rising epidemic of childhood obesity and diabetes, schools struggle to promote physical activities that help reduce risks for cardiovascular disease. Emerging data suggest that adopting novel activities into physical education (PE) curriculum may serve as an effective strategy for increasing physical activity in children. The purpose of this investigation was to characterize activity in the water and heart rates (HRs) of high school students participating in surf PE courses. Twenty-four male (n = 20) and female (n = 4) high school students (mean age = 16.7 ± 1.0 years) who were enrolled in surf PE courses at 2 high schools participated in this investigation. Daily measurements of surfing durations, average HR, and maximum HR were made on the students with HR monitors (PolarFT1) over an 8-week period. In addition, HR and activity in the water was evaluated during a single session in a subset of students (n = 11) using a HR monitor (PolarRCX5) and a video camera (Canon HD). Activity and HR were synchronized and evaluated in 5-second intervals during data analyses. The average duration that PE students participated in surfing during class was 61.7 ± 1.0 minutes. Stationary, paddling, wave riding, and miscellaneous activities comprised 42.7 ± 9.5, 36.7 ± 7.9, 2.9 ± 1.4, and 17.8 ± 11.4 percent of the surf session, respectively. The average and maximum HRs during these activities were 131.1 ± 0.9 and 177.2 ± 1.0 b·min, respectively. These data suggest that high school students participating in surf PE attained HRs and durations that are consistent with recommendations with cardiovascular fitness and health. In the future, PE programs should consider incorporating other action sports into their curriculum to enhance cardiovascular health. PMID:26562714

  1. A theoretical individual-based model of Brown Ring Disease in Manila clams, Venerupis philippinarum

    NASA Astrophysics Data System (ADS)

    Paillard, Christine; Jean, Fred; Ford, Susan E.; Powell, Eric N.; Klinck, John M.; Hofmann, Eileen E.; Flye-Sainte-Marie, Jonathan

    2014-08-01

    An individual-based mathematical model was developed to investigate the biological and environmental interactions that influence the prevalence and intensity of Brown Ring Disease (BRD), a disease, caused by the bacterial pathogen, Vibrio tapetis, in the Manila clam (Venerupis (= Tapes, = Ruditapes) philippinarum). V. tapetis acts as an external microparasite, adhering at the surface of the mantle edge and its secretion, the periostracal lamina, causing the symptomatic brown deposit. Brown Ring Disease is atypical in that it leaves a shell scar that provides a unique tool for diagnosis of either live or dead clams. The model was formulated using laboratory and field measurements of BRD development in Manila clams, physiological responses of the clam to the pathogen, and the physiology of V. tapetis, as well as theoretical understanding of bacterial disease progression in marine shellfish. The simulation results obtained for an individual Manila clam were expanded to cohorts and populations using a probability distribution that prescribed a range of variability for parameters in a three dimensional framework; assimilation rate, clam hemocyte activity rate (the number of bacteria ingested per hemocyte per day), and clam calcification rate (a measure of the ability to recover by covering over the symptomatic brown ring deposit), which sensitivity studies indicated to be processes important in determining BRD prevalence and intensity. This approach allows concurrent simulation of individuals with a variety of different physiological capabilities (phenotypes) and hence by implication differing genotypic composition. Different combinations of the three variables provide robust estimates for the fate of individuals with particular characteristics in a population that consists of mixtures of all possible combinations. The BRD model was implemented using environmental observations from sites in Brittany, France, where Manila clams routinely exhibit BRD signs. The simulated

  2. Sublethal effects of chromium-VI in the Asian clam (Potamocorbula amurensis).

    PubMed

    Teh, S J; Werner, I; Hinton, D E

    2000-01-01

    Previously, we have shown that Asian clams (Potamocorbula amurensis) with highest metallic body burdens have highest prevalence of disease and lowest reproduction. The present study was designed to assess and validate potential sublethal toxicity of hexavalent chromium (Cr-VI) in clams under controlled laboratory exposure. For 7 days, three replicates of clam (n = 10 per replicate) were exposed to aqueous solution containing 0.00, 0.92, 8.40, or 25.6 mg l-1 of Cr-VI at 15 degrees C and 15 g l-1 salinity. Mortality reached 100% in the 25.6 mg l-1 group within 7 days. There was no significant difference in mortality among the control, 0.92, and 8.40 mg l-1 groups. Western blot analyses revealed significantly elevated stress protein hsp70 levels in the 8.40 mg l-1 treatment group. Histopathologic analyses revealed mild digestive gland (DG) atrophy in the control group. Clams exposed to 0.92 mg l-1 Cr-VI showed moderate DG atrophy, moderate granulomatous inflammation and necrosis in DG, ovary and testis. Lesions observed in the 8.40 mg l-1 treatment group included severe DG atrophy, severe granulomatous inflammation and necrosis in byssal gland, DG, gill, kidney, ovary and testis. In gills and testes of treated groups, apoptotic cells outnumbered mitotic cells. In addition, gills from clams in the 8.40 mg l-1 group showed enhanced hsp70 staining. Our studies support a cause-effect relationship between contaminants and reduced health in Asian clams and indicate the DGs, gills, and reproductive organs are principal targets of Cr-VI toxicity at sublethal concentrations. Results from this study suggest that Cr-VI may have played a role in the increased incidence of diseased clams seen in previous studies and these adverse effects may be working to decrease clam populations at sites with highest metallic contamination in the San Francisco Bay Estuary. PMID:11460708

  3. Ionic and Amino Acid Regulation in Hard Clam (Meretrix lusoria) in Response to Salinity Challenges.

    PubMed

    Lin, Chia-Hao; Yeh, Po-Ling; Lee, Tsung-Han

    2016-01-01

    Most marine mollusks are osmoconformers, in that, their body fluid osmolality changes in the direction of the change in environmental salinity. Marine mollusks exhibit a number of osmoregulatory mechanisms to cope with either hypo- or hyperosmotic stress. The effects of changes in salinity on the osmoregulatory mechanisms of the hard clam (Meretrix lusoria, an economically important species of marine bivalve for Taiwan) have not been determined. In this study, we examined the effect of exposure to hypo (10‰)- and hyper (35‰)-osmotic salinity on hard clams raised at their natural salinity (20‰). The osmolality, [Na(+)], and [Cl(-)] of the hard clam hemolymph were changed in the same direction as the surrounding salinity. Further, the contents of total free amino acids including taurine in the gills and mantles were significantly upregulated in hard clam with increasing salinity. The gill Na(+), K(+)-ATPase (NKA) activity, the important enzyme regulating cellular inorganic ions, was not affected by the changed salinity. Mantle NKA activity, however, was stimulated in the 35‰ SW treatment. The taurine transporter (TAUT) is related to the regulation of intracellular contents of taurine, the dominant osmolyte. Herein, a TAUT gene of hard clam was cloned and a TAUT antibody was derived for the immunoblotting. The TAUT mRNA expression of the mantle in hard clam was significantly stimulated in 35‰ SW, but protein expression was not modulated by the changed salinity. In gills of the hard clam with 10‰ SW, both TAUT mRNA and protein expressions were significantly stimulated, and it may reflect a feedback regulation from the decreased gills taurine content under long-term hypoosmotic acclimation. These findings suggest that TAUT expression is regulated differently in gills and mantles following exposure to alterations in environmental salinity. Taken together, this study used the physiological, biochemical and molecular approaches to simultaneously explore the

  4. Detection of hepatitis A virus genotype IB variants in clams from Maputo Bay, Mozambique.

    PubMed

    Nenonen, Nancy P; Hernroth, Bodil; Chauque, Arlindo A; Hannoun, Charles; Bergström, Tomas

    2006-07-01

    Clams provide an important source of food and income for the population of Maputo, Mozambique, where conditions of poor water supply and inadequate sanitation favor endemic infection with hepatitis A virus (HAV). To determine the role of bivalves in an endemic area, clams gathered from Maputo Bay were bought from market and examined for HAV. Four batches, total 150 clams, were sampled over the year. RNA extracted from individual digestive glands was assayed by nested RT-PCR and sequencing of HAV 5' noncoding region (5' NCR). Specific HAV signals were detected in one batch, 23 of 34 clams (67%) testing positive. Phylogenetic analyses of VP3/VP1, VP1/P2A, and 5' NCR determined clustering of clam strains as genotype I, subtype B. In addition to identifying HAV IB strains with predicted conserved amino acid sequence, IB variants exhibiting novel amino acid substitutions at the VP1/P2A junction were detected. HAV strains from clams showed 93%-99% homology with wild-type IB strains from South African outbreaks and from a panel of HAV IgM positive Swedish patients. DNA from enteric human adenovirus 40/41 was found in a limited number of clams from two batches, 6/34 (17%) and 4/35 (11%). Detection of HAV subgenotype IB in bivalves provided indirect evidence of the strains circulating in a densely populated coastal region where HAV is presumed to be hyperendemic. The results suggest that clams may be an important source of HAV in Maputo region, and indicate the need for further molecular study of strains circulating in the indigenous population. PMID:16721847

  5. Ionic and Amino Acid Regulation in Hard Clam (Meretrix lusoria) in Response to Salinity Challenges

    PubMed Central

    Lin, Chia-Hao; Yeh, Po-Ling; Lee, Tsung-Han

    2016-01-01

    Most marine mollusks are osmoconformers, in that, their body fluid osmolality changes in the direction of the change in environmental salinity. Marine mollusks exhibit a number of osmoregulatory mechanisms to cope with either hypo- or hyperosmotic stress. The effects of changes in salinity on the osmoregulatory mechanisms of the hard clam (Meretrix lusoria, an economically important species of marine bivalve for Taiwan) have not been determined. In this study, we examined the effect of exposure to hypo (10‰)- and hyper (35‰)-osmotic salinity on hard clams raised at their natural salinity (20‰). The osmolality, [Na+], and [Cl−] of the hard clam hemolymph were changed in the same direction as the surrounding salinity. Further, the contents of total free amino acids including taurine in the gills and mantles were significantly upregulated in hard clam with increasing salinity. The gill Na+, K+-ATPase (NKA) activity, the important enzyme regulating cellular inorganic ions, was not affected by the changed salinity. Mantle NKA activity, however, was stimulated in the 35‰ SW treatment. The taurine transporter (TAUT) is related to the regulation of intracellular contents of taurine, the dominant osmolyte. Herein, a TAUT gene of hard clam was cloned and a TAUT antibody was derived for the immunoblotting. The TAUT mRNA expression of the mantle in hard clam was significantly stimulated in 35‰ SW, but protein expression was not modulated by the changed salinity. In gills of the hard clam with 10‰ SW, both TAUT mRNA and protein expressions were significantly stimulated, and it may reflect a feedback regulation from the decreased gills taurine content under long-term hypoosmotic acclimation. These findings suggest that TAUT expression is regulated differently in gills and mantles following exposure to alterations in environmental salinity. Taken together, this study used the physiological, biochemical and molecular approaches to simultaneously explore the

  6. Sediment-contact and survival of fingernail clams: Implications for conducting short-term laboratory tests

    USGS Publications Warehouse

    Naimo, T.J.; Cope, W.G.; Bartsch, M.R.

    2000-01-01

    Porewater toxicity tests have been used as indicators of whole sediment toxicity. However, many species commonly tested in porewater predominately reside in the water column and otherwise have little to no direct contact with sediment and associated porewater. We assessed the feasibility of porewater toxicity tests with fingernail clams Musculium transversum, a benthic macroinvertebrate that inhabits soft bottom sediments and feeds by filtering surface and porewater. Fingernail clams were exposed to water or sediment in a 96 h laboratory test with a 5 x 2 factorial experimental design. The five treatments included sediments from four sites in the Mississippi River and one sediment-free control (well water). In all treatments, clams were exposed to the sediments or water either directly (no enclosure) or indirectly (enclosure, suspended above the sediment surface). There were three replicates for each of the ten treatment combinations. Overall, survival of fingernail clams did not vary among the five treatments (p = 0.36). In treatments without enclosures, survival of clams in the sediment-free control was not significantly different (p = 0.34) from the sediment-containing treatments. Survival of clams in the sediment-free control averaged 85 - suggesting that direct sediment contact is not necessary for survival in short-term tests. In contrast, survival of clams in the sediment-containing treatments differed significantly (p = 0.03) between exposures with (mean, 77) and without (mean, 89) enclosures. Thus, fingernail clams may provide an alternative species for evaluating benthic macroinvertebrates in short-term laboratory porewater tests. However, more information on their physiological requirements and the development of sublethal endpoints is recommended before their use in tests of longer duration. (C) 2000 by John Wiley and Sons, Inc.

  7. Ozone depuration of Vibrio vulnificus from the southern quahog clam, Mercenaria campechiensis

    SciTech Connect

    Schneider, K.R.; Steslow, F.S.; Sierra, F.S.; Rodrick, G.E.; Noss, C.I. )

    1991-03-01

    Southern quahog clams, Mercenaria campechiensis, were dosed with Vibrio vulnificus and placed in a pilot-scale depuration system using ozonated recirculated artificial seawater. Twenty-four hours of treatment with ozone-treated recirculating artificial seawater reduced the numbers of V. vulnificus in the shellfish meats by an average of 2 log units when compared to natural die-off in control clams. The oxidant levels (up to 3 mg/liter) did not adversely affect shellfish pumping during the depuration process.

  8. Testing gravity using dwarf stars

    NASA Astrophysics Data System (ADS)

    Sakstein, Jeremy

    2015-12-01

    Generic scalar-tensor theories of gravity predict deviations from Newtonian physics inside astrophysical bodies. In this paper, we point out that low mass stellar objects, red and brown dwarf stars, are excellent probes of these theories. We calculate two important and potentially observable quantities: the radius of brown dwarfs and the minimum mass for hydrogen burning in red dwarfs. The brown dwarf radius can differ significantly from the general relativity prediction, and upcoming surveys that probe the mass-radius relation for stars with masses dwarf stars. This places a new and extremely stringent constraint on the parameters that appear in the effective field theory of dark energy and rules out several well-studied dark energy models.

  9. Lipid characteristics of a seep clam, Mesolinga soliditesta: Comparison with those of two coastal clams, Meretrix lamarckii and Ruditapes philippinarum

    NASA Astrophysics Data System (ADS)

    Saito, Hiroaki; Murata, Masakazu; Hashimoto, Jun

    2014-12-01

    The lipids and fatty acids of two coastal clams, Meretrix lamarckii and Ruditapes philippinarum, collected at 5 and 1 m of depth, and a seep clam, Mesolinga soliditesta, collected at 331 m of depth, were examined to assess their lipid physiology and trophic relationship with their diets. The major fatty acids of lipids in Mer. lamarckii and R. philippinarum were 14:0, 16:0, 18:0, 16:1n-7, 18:1n-9, 18:1n-7, 20:4n-6, 20:5n-3, and 22:6n-3, while those of Mes. soliditesta were 16:0, 18:0, 16:1n-7, 18:1n-7, 20:1n-7, 20:1n-13, 20:2n-7, 15 (Δ5,13-20:2), and 22:2n-7,15 (Δ7,15-22:2). The major polyunsaturated fatty acids (PUFAs) in the Mer. lamarckii and R. philippinarum lipids consisted of various n-3 and n-6 long-chain (LC) PUFAs, such as 20:4n-6, 22:4n-6, 20:5n-3, 22:5n-3, and 22:6n-3, while those in Mes. soliditesta muscle and viscera included various n-4 family PUFAs (18:3n-7, 18:4n-4, 20:2n-7, and 20:3n-7) with limited kinds of n-3 and n-6 PUFAs (20:4n-6 and 20:5n-3). These findings indicate that, like other common shallow-water clams, Mer. lamarckii and R. philippinarum ingest phytoplanktonic n-3 and n-6 LC-PUFAs, whereas Mes. soliditesta utilizes limited kinds of n-3 and n-6 LC-PUFAs. In contrast to the other two bivalves species, Mes. soliditesta yielded various n-4 and n-7 (n-4/n-7) PUFAs, which were assimilated from the chemosynthetic symbionts. The high diversity of PUFAs contained in the Mes. soliditesta lipids (n-3, n-4 family, and n-6 PUFAs) suggests that this species mixotrophically utilized both photosynthetic products and vent chemosynthetic nutrition derived from geothermal energy.

  10. Barley yellow dwarf viruses.

    PubMed

    Miller, W A; Rasochová, L

    1997-01-01

    Barley yellow dwarf viruses represent one of the most economically important and ubiquitous groups of plant viruses. This review focuses primarily on four research areas in which progress has been most rapid. These include (a) evidence supporting reclassification of BYDVs into two genera; (b) elucidation of gene function and novel mechanisms controlling gene expression; (c) initial forays into understanding the complex interactions between BYDV virions and their aphid vectors; and (d) replication of a BYDV satellite RNA. Economic losses, symptomatology, and means of control of BYD are also discussed. PMID:15012520

  11. Dwarfs in Coma Cluster

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on image for larger poster version

    This false-color mosaic of the central region of the Coma cluster combines infrared and visible-light images to reveal thousands of faint objects (green). Follow-up observations showed that many of these objects, which appear here as faint green smudges, are dwarf galaxies belonging to the cluster. Two large elliptical galaxies, NGC 4889 and NGC 4874, dominate the cluster's center. The mosaic combines visible-light data from the Sloan Digital Sky Survey (color coded blue) with long- and short-wavelength infrared views (red and green, respectively) from NASA's Spitzer Space Telescope.

  12. Seeing Baby Dwarf Galaxies

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] [figure removed for brevity, see original site] Visible/DSS Click on image for larger version Ultraviolet/GALEX Click on image for larger version Poster Version Click on image for larger version

    The unique ultraviolet vision of NASA's Galaxy Evolution Explorer reveals, for the first time, dwarf galaxies forming out of nothing more than pristine gas likely leftover from the early universe. Dwarf galaxies are relatively small collections of stars that often orbit around larger galaxies like our Milky Way.

    The forming dwarf galaxies shine in the far ultraviolet spectrum, rendered as blue in the call-out on the right hand side of this image. Near ultraviolet light, also obtained by the Galaxy Evolution Explorer, is displayed in green, and visible light from the blue part of the spectrum here is represented by red. The clumps (in circles) are distinctively blue, indicating they are primarily detected in far ultraviolet light.

    The faint blue overlay traces the outline of the Leo Ring, a huge cloud of hydrogen and helium that orbits around two massive galaxies in the constellation Leo (left panel). The cloud is thought likely to be a primordial object, an ancient remnant of material that has remained relatively unchanged since the very earliest days of the universe. Identified about 25 years ago by radio waves, the ring cannot be seen in visible light.

    Only a portion of the Leo Ring has been imaged in the ultraviolet, but this section contains the telltale ultraviolet signature of recent massive star formation within this ring of pristine gas. Astronomers have previously only seen dwarf galaxies form out of gas that has already been cycled through a galaxy and enriched with metals elements heavier than helium produced as stars evolve.

    The visible data come from the Digitized Sky Survey of the Space Telescope Science Institute in Baltimore, Md. The

  13. Adaptation of respiratory chain biogenesis to cytochrome c oxidase deficiency caused by SURF1 gene mutations.

    PubMed

    Kovářová, Nikola; Cížková Vrbacká, Alena; Pecina, Petr; Stránecký, Viktor; Pronicka, Ewa; Kmoch, Stanislav; Houštěk, Josef

    2012-07-01

    The loss of Surf1 protein leads to a severe COX deficiency manifested as a fatal neurodegenerative disorder, the Leigh syndrome (LS(COX)). Surf1 appears to be involved in the early step of COX assembly but its function remains unknown. The aim of the study was to find out how SURF1 gene mutations influence expression of OXPHOS and other pro-mitochondrial genes and to further characterize the altered COX assembly. Analysis of fibroblast cell lines from 9 patients with SURF1 mutations revealed a 70% decrease of the COX complex content to be associated with 32-54% upregulation of respiratory chain complexes I, III and V and accumulation of Cox5a subunit. Whole genome expression profiling showed a general decrease of transcriptional activity in LS(COX) cells and indicated that the adaptive changes in OXPHOS complexes are due to a posttranscriptional compensatory mechanism. Electrophoretic and WB analysis showed that in mitochondria of LS(COX) cells compared to controls, the assembled COX is present entirely in a supercomplex form, as I-III₂-IV supercomplex but not as larger supercomplexes. The lack of COX also caused an accumulation of I-III₂ supercomplex. The accumulated Cox5a was mainly present as a free subunit. We have found out that the major COX assembly subcomplexes accumulated due to SURF1 mutations range in size between approximately 85-140kDa. In addition to the originally proposed S2 intermediate they might also represent Cox1-containing complexes lacking other COX subunits. Unlike the assembled COX, subcomplexes are unable to associate with complexes I and III. PMID:22465034

  14. Radiation stress gradients across the surf zone for hurricane wave forcing: theory and observations

    NASA Astrophysics Data System (ADS)

    Mulligan, R. P.; Bowen, A. J.; Hanson, J. L.; Hathaway, K. K.

    2012-12-01

    Wave breaking is a non-linear, turbulent and chaotic phenomenon that is the overwhelmingly dominant physical process acting along beaches and coasts exposed to surface waves during storms. The breaking process causes large rates of wave energy dissipation over short distances and the momentum that is exchanged with the mean flow is the dominant forcing for currents and water level changes across nearshore region. Inside the surf zone, this can outweigh other flow forcing mechanisms such as winds and tides by several orders of magnitude. We examine Eulerian observations from six sensor sites the USACE FRF cross-shore array for several large hurricane wave events with wide surf zones, to elucidate the nearshore balance of momentum under storm conditions. Under such strong wave forcing, observations of longshore currents up to 2 m/s and mean cross-shore flows up to 0.3 m/s near the 5 m isobath are presented for wave events that impacted the U.S. Atlantic coast in 2009-2011 including Hurricanes Bill, Earl and Irene. An investigation of the mass flux and momentum terms across the surf zone indicates that the radiation stress gradient in the cross-shore direction can exceed the momentum that can be balanced by the pressure gradient and results in significant bottom stress term and thus an offshore directed cross-shore flow. The mean cross-shore flow contributes to advection of alongshore momentum and although small when integrated across the whole surf zone, is locally important especially near the outer edge of the surf zone.

  15. Evaluating sublethal indicators of stress in Asiatic clams (Corbicula fluminea) caged in an urban stream

    SciTech Connect

    Black, M.C.; Belin, J.I.

    1998-12-31

    Freshwater bivalves have been used extensively to monitor chemical accumulation in field exposures, although little information is available on the use of biomarker measurements in field exposures with bivalves. DNA strand breakage, growth rate, condition index and percentage tissue water were measured in freshwater Asiatic clams (Corbicula fluminea) exposed in-situ in a stream that receives urban and industrial stormwater runoff and in a non-impacted reference stream. After 4 weeks exposure, DNA strand lengths in foot tissue from Trail Creek-exposed clams were significantly shorter than DNA from reference clams. These results suggest a reduction in DNA integrity in Trail Creek-exposed clams, possibly indicating exposure to genotoxic chemicals. No significant differences were observed in the growth rates of clams. However, a significant inverse relationship was detected between condition index and % tissue water for all clams. Furthermore, site-specific differences in percentage tissue water and condition indices were observed after 2 and 10 weeks exposure. For this study DNA strand breakage, condition indices, and tissue hydration appear to be more sensitive indicators of sublethal toxicity than growth.

  16. Management strategies to optimise sustainable clam ( Tapes philippinarum) harvests in Barbamarco Lagoon, Italy

    NASA Astrophysics Data System (ADS)

    Spillman, C. M.; Hamilton, D. P.; Imberger, J.

    2009-01-01

    Barbamarco Lagoon is a small lagoon adjoining the Northern Adriatic Sea and is the site of a commercially valuable clam ( Tapes philippinarum) fishery. A three-dimensional (3D) coupled hydrodynamic-ecological model was applied to the lagoon with the objective of assessing impacts on clam food supply, commercial harvests and water quality of different clam rearing strategies, lagoon morphologies and flow regimes. Harvest and net growth to seeding ratios, total harvest value, clearance efficiencies and clam satiety were used to quantify the commercial success of different management strategies, while bottom dissolved oxygen concentrations were used as an indicator of ecosystem health. Increasing exchange with the Northern Adriatic Sea or increasing freshwater inputs into the lagoon improved clam food supply and increased both harvest production and ecosystem health in model simulations of the system. Results indicated that the high spatial and temporal variability of clam production and water quality responses must be considered for a holistic assessment of the outcomes of strategies in the context of ecological and production carrying capacity.

  17. Automated parasites detection in clams by transillumination imaging and pattern classification

    NASA Astrophysics Data System (ADS)

    Soto, Miguel; Coelho, Pablo; Soto, Jose; Torres, Sergio; Sbarbaro, Daniel

    2012-01-01

    Quality control of clams considers the detection of foreign objects like shell pieces, sand and even parasites. Particularly, Mulinia edulis clams are susceptible to have a parasite infection caused by the isopoda Edotea magellanica, which represents a serious commercial problem commonly addressed by manual inspection. In this work a machine vision system capable of automatically detect the parasite using a clam image is presented. The parasite visualization inside the clam is achieved by an optoelectronic imaging system based on an transillumination technique. Furthermore, automatic parasite detection in the clam's image is accomplished by a pattern recognition system designed to quantitatively describe parasite candidate zones. The extracted features are used to predict the parasite presence by means of a binary decision tree classifier. A real sample dataset of more than 155000 patterns of parasite candidate zones was generated using 190 shell-off cooked clams from the Chilean south pacific coasts. This data collection was used to train a test the classifier using cross-validation. Primary results have shown a mean parasite detection rate of 85% and a mean total correct classification of 87%, which represent a substantive improvement to the existing solutions.

  18. Microplastic Ingestion by Wild and Cultured Manila Clams (Venerupis philippinarum) from Baynes Sound, British Columbia.

    PubMed

    Davidson, Katie; Dudas, Sarah E

    2016-08-01

    Microplastics, plastic particles <5 mm, are an emerging concern in aquatic ecosystems. Because microplastics are small, they are available to many filter-feeding organisms, which can then be consumed by higher trophic level organisms, including humans. This study documents the quantity of microplastics present in wild and cultured Manila clams (Venerupis philippinarum). Three active shellfish farms and three reference beaches (i.e., non-shellfish farm sites) in Baynes Sound, British Columbia were chosen to examine the microplastic concentrations in wild and cultured Manila clams. Microplastics were isolated using a nitric acid digestion technique and enumerated from 54 clams (27 farmed and 27 non-farmed). Qualitative attributes, such as colour and microplastic type (fiber, fragment, or film) also were recorded. There was no significant difference (F = 1.29; df = 1,4; P = 0.289) between microplastic concentrations in cultured and wild clams. Microplastic concentrations ranged from 0.07 to 5.47 particles/g (from reference beach and shellfish farm clams, respectively). Fibers were the dominant microplastic (90 %); colourless and dark gray fibers were the most common colours observed (36 and 26 %, respectively). Although this indicates that microplastics are definitely present in seafood consumed by humans, shellfish aquaculture operations do not appear to be increasing microplastic concentrations in farmed clams in this region. PMID:27259879

  19. Soft shell clams Mya arenaria with disseminated neoplasia demonstrate reverse transcriptase activity

    USGS Publications Warehouse

    House, M.L.; Kim, C.H.; Reno, P.W.

    1998-01-01

    Disseminated neoplasia (DN), a proliferative cell disorder of the circulatory system of bivalves, was first reported in oysters in 1969. Since that time, the disease has been determined to be transmissible through water-borne exposure, but the etiological agent has not been unequivocally identified. In order to determine if a viral agent, possibly a retrovirus, could be the causative agent of DN, transmission experiments were performed, using both a cell-free filtrate and a sucrose gradient-purified preparation of a cell-free filtrate of DN positive materials. Additionally, a PCR-enhanced reverse transcriptase assay was used to determine if reverse transcriptase was present in tissues or hemolymph from DN positive soft shell clams Mya arenaria. DN was transmitted to healthy clams by injection with whole DN cells, but not with cell-free flitrates prepared from either tissues from DN positive clams, or DN cells. The cell-free preparations from DN-positive tissues and hemolymph having high levels of DN cells in circulation exhibited positive reactions in the PCR-enhanced reverse transcriptase assay. Cell-free preparations of hemolymph from clams having low levels of DN (<0.1% of cells abnormal), hemocytes from normal soft shell clams, and normal soft shell clam tissues did not produce a positive reaction in the PCR enhanced reverse transcriptase assay.

  20. Spatial distribution and bioaccumulation patterns in three clam populations from a low contaminated ecosystem

    NASA Astrophysics Data System (ADS)

    Velez, Cátia; Figueira, Etelvina; Soares, Amadeu; Freitas, Rosa

    2015-03-01

    When consuming bivalves, special concern should be taken to the total element burden. In order to assess this issue the present study aimed to measure the element levels in the sediments of different harvesting areas and relate them with clam accumulation; to assess the elements body burden, their availability for trophic transfer and relate it with total accumulation in clams, comparing the native (Ruditapes decussatus and Venerupis corrugata) and the invasive (Ruditapes philippinarum) species; to evaluate the human risk associated with the consumption of different clam species. The results showed that the element burden in clams does not reflect the sediment contamination and BAF values were higher in the less contaminated areas. Comparison of Maximum Levels (MLs) from international organizations with the concentration of elements in clams showed that As exceeded standard levels. The ingestion of less than 1 Kg per week of clams would result in exceeding the PTWI threshold for As. Furthermore, the results showed that, when comparing to other elements, As and Hg are more easily available to be transferred trophically.

  1. White Dwarf Stars

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Peering deep inside a cluster of several hundred thousand stars, NASA's Hubble Space Telescope has uncovered the oldest burned-out stars in our Milky Way Galaxy, giving astronomers a fresh reading on the age of the universe.

    Located in the globular cluster M4, these small, burned-out stars -- called white dwarfs -- are about 12 to 13 billion years old. By adding the one billion years it took the cluster to form after the Big Bang, astronomers found that the age of the white dwarfs agrees with previous estimates that the universe is 13 to 14 billion years old.

    The images, including some taken by Hubble's Wide Field and Planetary Camera 2, are available online at

    http://oposite.stsci.edu/pubinfo/pr/2002/10/ or

    http://www.jpl.nasa.gov/images/wfpc .

    The camera was designed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif.

    In the top panel, a ground-based observatory snapped a panoramic view of the entire cluster, which contains several hundred thousand stars within a volume of 10 to 30 light-years across. The Kitt Peak National Observatory's .9-meter telescope took this picture in March 1995. The box at left indicates the region observed by the Hubble telescope.

    The Hubble telescope studied a small region of the cluster. A section of that region is seen in the picture at bottom left. A sampling of an even smaller region is shown at bottom right. This region is only about one light-year across. In this smaller region, Hubble pinpointed a number of faint white dwarfs. The blue circles indicate the dwarfs. It took nearly eight days of exposure time over a 67-day period to find these extremely faint stars.

    Globular clusters are among the oldest clusters of stars in the universe. The faintest and coolest white dwarfs within globular clusters can yield a globular cluster's age. Earlier Hubble observations showed that the first stars formed less than 1 billion years after the universe's birth in the big bang. So, finding the

  2. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (south Atlantic): Hard clam. [Mercenaria mercenaria

    SciTech Connect

    Eversole, A.G.

    1987-08-01

    The hard clam, Mercenaria mercenaria, supports an important commercial fishery in the South Atlantic, averaging about 1 million kg of meats annually from 1979 to 1983. It also is an important constituent of estuarine systems throughout the region. Spawning occurs in the spring and the fall at 16 to 30/sup 0/C. Planktonic eggs and larvae are carried by water currents, and larvae set sometime after 6 days of age. Mortality is highest in egg and larval stages, the most sensitive part of the life cycle. Spat display gregarious setting behavior and appear to select sand over finer substrates. Highest densities of clams occur in sandy bottoms with shell. Crab predation is an important factor influencing the density and distribution of clams. Blue crabs and mud crabs appear to be the most important predators. Hard clams are infested by few parasites. Adult clams feed by filtering suspended particulate matter from the water. Growth of clams decreases with size and age. Growth occurs year-round with peaks in spring and fall. Growth of adult hard clams occurs at 9 to 31/sup 0/C and at 4 to 35 ppt (optima near 20/sup 0/C and 24 to 28 ppt). Hard clams mature in 2 years and reach commercial size in 3 years in the South Atlantic. Tight-fitting shells permit hard clams to survive poor water quality for short periods.

  3. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Mid-Atlantic): Softshell clam. [Mya arenaria

    SciTech Connect

    Abraham, B.J.; Dillon, P.L.

    1986-08-01

    The softshell clam supports the third most valuable commercial clam fishery in the United States. Density is highest at depths of 3 to 4 m, temperatures less than 28/sup 0/C, and salinities greater than 3 ppt. Its near-shore habitat makes it easily threatened by pollution. Clam beds in some places have been closed because of contamination by bacteria. Softshell clams are more sensitive to oil pollution than are the other clams that share its habitat. The softshell clam spawns in spring (sometimes in early summer) and again in fall. In 36 to 48 h after fertilization, a pelagic veliger larva develops and persists for 2 to 6 weeks. Then it settles out of the plankton. It attaches to the substrate and can move and reattach itself. Eventually, it adopts the adult lifestyle and occupies a permanent burrow, usually in sandy bottom with less than 50% silt. Adult clams feed by filtering small particles from the water column. Predators of adult clams include crabs, fish, birds, and raccoons. The 24-h LC/sub 50/ values for summer-acclimated clams have been reported as 32.5 to 34.4/sup 0/C. Juveniles and adults can withstand long periods of anaerobiosis.

  4. Temperature- and parasite-induced changes in toxicity and lethal body burdens of pentachlorophenol in the freshwater clam Pisidium amnicum.

    PubMed

    Heinonen, J; Kukkonen, J V; Holopainen, I J

    2001-12-01

    Seasonal variation in abiotic and biotic environments may modify the toxicity of organic chemicals for aquatic organisms. In present study, survival of the freshwater clam Pisidium amnicum was studied in laboratory exposures to pentachlorophenol (PCP) in April (at 5 degress C) and July (at 19 degress C). Behavioral responses, mean survival times (MSTs), and the lethal body burdens (LBBs) of PCP for uninfected clams and for clams infected by digenean trematodes were determined separately in two PCP concentrations, 100 and 300 microgram/L. Analysis of data revealed reduced behavioral activity of the clams in the PCP exposure compared to that in the control. The time needed for toxic responses was greatly affected by temperature; MSTs were 5 to 15 times longer in winter than at summer temperatures. Unexpectedly, the infected clams in summer were more tolerant to PCP than the uninfected clams. Despite the differences in survival times, the LBBs between the seasons were constant. However, in summer, the infected clams had significantly higher LBBs than the uninfected clams. The differences in survival and LBBs between the infected and uninfected clams are suggested to be caused by the high lipid contents found in parasites, which may change the internal distribution of PCP. PMID:11764161

  5. PROPERTIES OF THE COOLEST DWARFS

    SciTech Connect

    SAUMON, DIDIER; LEGGETT, SANDY K.; FREEDMAN, RICHARD S.; GEBALLE, THOMAS R.; GOLIMOWSKI, DAVID A.; LODIEU, NICOLAS; MARLEY, MARK S.; STEPHENS, DENISE; PINFIELD, DAVID J.; WARREN, STEPHEN J.

    2007-01-18

    Eleven years after the discovery of the first T dwarf, we have a population of ultracool L and T dwarfs that is large enough to show a range of atmospheric properties, as well as model atmospheres advanced enough to study these properties in detail. Since the last Cool Stars meeting, there have been observational developments which aid in these studies. they present recent mid-infrared photometry and spectroscopy from the Spitzer Space Telescope which confirms the prevalence of vertical mixing in the atmospheres of L and T dwarfs. Hence, the 700 K to 2200 K L and t dwarf photspheres require a large number of parameters for successful modeling: effective temperature, gravity, metallicity, grain sedimentation and vertical mixing efficiency. They also describe initial results of a search for ultracool dwarfs in the UKIRT Infrared Deep Sky Survey, and present the latest T dwarf found to date. They conclude with a discussion of the definition of the later-than-T spectral type, the Y dwarf.

  6. CpG methylation has differential effects on the binding of YY1 and ETS proteins to the bi-directional promoter of the Surf-1 and Surf-2 genes.

    PubMed Central

    Gaston, K; Fried, M

    1995-01-01

    The divergently transcribed Surf-1 and Surf-2 housekeeping genes are separated by a bi-directional, TATA-less promoter which lies within a CpG-rich island. Here we show that CpG methylation severely reduces transcription in the direction of both Surf-1 and Surf-2. Previous work has identified three promoter elements (Su1, Su2 and Su3) which are conserved between the human and mouse Surf-1/Surf-2 promoters. These elements bind transcription factors present in human and mouse cell nuclear extracts in vitro and mutations which prevent factor binding also reduce promoter activity in vivo. Transcription initiation factor YY1 binds to the Su1 site and stimulates transcription in the direction of Surf-1 and, to a lesser extent, Surf-2. Here we show that members of the ETS family of transcription factors bind to the Su2 site. Although the Su1 factor binding site contains three CpG dinucleotides, the binding of YY1 is not affected by CpG methylation. In contrast, CpG methylation abolishes the binding of ETS proteins to the Su2 site; methylation of a single cytosine, at position 3 of the consensus ETS site, is sufficient to prevent factor binding. This direct effect on the binding of ETS proteins is, however, not in itself sufficient to explain the repression of this promoter by CpG methylation. A mutation of the Su2 site which removes the sequence CpG, but which does not prevent ETS factor binding, fails to relieve this promoter from repression by CpG methylation. Images PMID:7731802

  7. Magnetic Field of Strange Dwarfs

    NASA Astrophysics Data System (ADS)

    Baghdasaryan, D. S.

    2016-03-01

    The generation of a magnetic field in a strange quark star owing to differential rotation of the superfluid and superconducting quark core relative to the normal electron-nuclear crust of the star is examined. The maximum possible magnetic field on the surface is estimated for various models of strange dwarfs. Depending on the configuration parameters, i.e., the mass M and radius R of the star, a range of 103-105 G is found. These values of the magnetic field may be an additional condition for identification of strange dwarfs among the extensive class of observed white dwarfs.

  8. Drones at the Beach - Surf Zone Monitoring Using Rotary Wing Unmanned Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Rynne, P.; Brouwer, R.; de Schipper, M. A.; Graham, F.; Reniers, A.; MacMahan, J. H.

    2014-12-01

    We investigate the potential of rotary wing Unmanned Aerial Vehicles (UAVs) to monitor the surf zone. In recent years, the arrival of lightweight, high-capacity batteries, low-power electronics and compact high-definition cameras has driven the development of commercially available UAVs for hobbyists. Moreover, the low operation costs have increased their potential for scientific research as these UAVs are extremely flexible surveying platforms. The UAVs can fly for ~12 min with a mean loiter radius of 1 - 3.5 m and a mean loiter error of 0.75 - 4.5 m, depending on the environmental conditions, flying style, battery type and vehicle type. Our experiments using multiple, alternating UAVs show that it is possible to have near continuous imagery data with similar Fields Of View. The images obtained from the UAVs (Fig. 1a), and in combination with surveyed Ground Control Points (GCPs) (Fig. 1b, red squares and white circles), can be geo-rectified (Fig. 1c) to pixel resolution between 0.01 - 1 m and a reprojection error, i.e. the difference between the surveyed GPS location of a GCP and the location of the GCP obtained from the geo-rectified image, of O(1 m). These geo-rectified images provide data on a variety of coastal aspects, such as beach width (Wb(x,t)), surf zone width (Wsf(x,t)), wave breaking location (rectangle B), beach usage (circle C) and location of dune vegegation (rectangle D), amongst others. Additionally, the possibility to have consecutive, high frequency (up to 2 Hz) rectified images makes the UAVs a great data instrument for spatially and temporally variable systems, such as the surf zone. Our first observations with the UAVs reveal the potential to quickly obtain surf zone and beach characteristics in response to storms or for day to day beach information, as well as the scientific pursuits of surf zone kinematics on different spatial and temporal scales, and dispersion and advection estimates of pollutants/dye. A selection of findings from

  9. SURF's Up: An Outline of an Innovative Framework for Teaching Mental Computation to Students in the Early Years of Schooling

    ERIC Educational Resources Information Center

    Russo, James

    2015-01-01

    In this article James Russo presents the Strategies, Understanding, Reading and Fast Facts Framework (SURF) for mental computation. He explains how this framework can be used to deepen mathematical understanding and build mental flexibility.

  10. Influence of atmospheric parameters on vertical profiles and horizontal transport of aerosols generated in the surf zone

    NASA Astrophysics Data System (ADS)

    Kusmierczyk-Michulec, J.; Tedeschi, G.; Van Eijk, A. M. J.; Piazzola, J.

    2013-10-01

    The vertical and horizontal transport of aerosols generated over the surf zone is discussed. Experimental data were collected during the second campaign of the Surf Zone Aerosol Experiment that took place in Duck NC (USA) in November 2007. The Empirical Orthogonal Function (EOF) method was used to analyze the vertical concentration gradients, and allowed separating the surf aerosols from aerosols advected from elsewhere. The numerical Marine Aerosol Concentration Model (MACMod) supported the analysis by confirming that the concentration gradients are more pronounced under stable conditions and that aerosol plumes are then more confined to the surface. The model also confirmed the experimental observations made during two boat runs along the offshore wind vector that surf-generated aerosols are efficiently advected out to sea over several tens of kilometers.