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Sample records for hypersaline dead sea

  1. Anaerobic oxidation of methane by sulfate in hypersaline groundwater of the Dead Sea aquifer.

    Science.gov (United States)

    Avrahamov, N; Antler, G; Yechieli, Y; Gavrieli, I; Joye, S B; Saxton, M; Turchyn, A V; Sivan, O

    2014-11-01

    Geochemical and microbial evidence points to anaerobic oxidation of methane (AOM) likely coupled with bacterial sulfate reduction in the hypersaline groundwater of the Dead Sea (DS) alluvial aquifer. Groundwater was sampled from nine boreholes drilled along the Arugot alluvial fan next to the DS. The groundwater samples were highly saline (up to 6300 mm chlorine), anoxic, and contained methane. A mass balance calculation demonstrates that the very low δ(13) CDIC in this groundwater is due to anaerobic methane oxidation. Sulfate depletion coincident with isotope enrichment of sulfur and oxygen isotopes in the sulfate suggests that sulfate reduction is associated with this AOM. DNA extraction and 16S amplicon sequencing were used to explore the microbial community present and were found to be microbial composition indicative of bacterial sulfate reducers associated with anaerobic methanotrophic archaea (ANME) driving AOM. The net sulfate reduction seems to be primarily controlled by the salinity and the available methane and is substantially lower as salinity increases (2.5 mm sulfate removal at 3000 mm chlorine but only 0.5 mm sulfate removal at 6300 mm chlorine). Low overall sulfur isotope fractionation observed ((34) ε = 17 ± 3.5‰) hints at high rates of sulfate reduction, as has been previously suggested for sulfate reduction coupled with methane oxidation. The new results demonstrate the presence of sulfate-driven AOM in terrestrial hypersaline systems and expand our understanding of how microbial life is sustained under the challenging conditions of an extremely hypersaline environment. © 2014 The Authors. Geobiology Published by John Wiley & Sons Ltd.

  2. Hypersaline Subsurface Microbial Communities from the Dead Sea Viewed from Their Metagenomes.

    Science.gov (United States)

    Thomas, C.; Ionescu, D.; Ariztegui, D.

    2014-12-01

    The Dead Sea Deep Drilling Project (DSDDP) is an international research initiative aiming to reconstruct the paleoenvironmental and paleoseismic history of the Dead Sea Basin (DSB) in the Levantine region. Within this framework, analysis of microbial communities intend to qualify the extent of life in this extreme environment, the factors allowing its development and their contribution to the sedimentary and geochemical record. The extreme chemistry of the Dead Sea prevents the use of common in situ imaging techniques leaving little information on the general activity of the subsurface biosphere. Cloning and metagenomic techniques have however been implemented at different levels of a 457 m deep core. Results suggest a differential development or survival of the microbial community along the sedimentary column. Reasons for such distribution remain unclear but cannot only be imparted to salinity. Poorly known communities (e.g. Candidate Divisions MSBL1 and KB1) with strong potential for adaptations to anoxic hypersaline environments are recovered in some intervals. Halobacteria classes generally dominate the assemblages. Metagenomic data allowed characterizing their presence in two evaporitic facies of the core (aragonite at 2.7 m and gypsum at 90.6 m below lake floor), where they exhibit both salt-in and salt-out strategies to cope with the high salinities of the Dead Sea. Metabolisms are also adapted to the high heavy metal concentrations and low nutrient availability in the sediment. Although more work is needed in order to infer the impact of these microorganisms on the sediment and element cycles, indices of methanogenesis, fermentation and sulfate reducing activity imply influence on the carbon and sulfur cycle of the Dead Sea subsurface. This is highlighted by traces of microbial degradation of organic matter viewed under SEM, and by the formation of euhedral Fe-S mineralizations as a result of reduction of sulfur. Overall, this work calls for the importance

  3. Continuous CO2 escape from the hypersaline Dead Sea caused by aragonite precipitation

    Science.gov (United States)

    Golan, Rotem; Lazar, Boaz; Wurgaft, Eyal; Lensky, Nadav; Ganor, Jiwchar; Gavrieli, Ittai

    2017-06-01

    Chemical precipitation of CaCO3 occurs in diverse marine and lacustrine environments. In the hypersaline Ca-chloride lakes that have been occupying the Dead Sea basin since the late Pleistocene, CaCO3 precipitated, mostly as aragonite. The aragonite sediments precipitated mainly during periods of high lake level stands as a result of mixing of bicarbonate-rich freshwater runoff with Dead Sea brine, that is Ca-rich and have high Mg/Ca ratio. During periods of arid conditions with limited freshwater inflow, water level declined, salinity increased and gypsum and halite became the dominant evaporitic minerals to precipitate. The present study investigates the carbon cycle of the Dead Sea under the current limited water and bicarbonate supply to the brine, representing periods of extremely arid conditions. The decrease of inflows to the Dead Sea in recent years stems mainly from diversion of freshwater from the drainage basin and results in dramatic water level decline and massive halite precipitation. During 2013-2014, bi-monthly depth profiles of total alkalinity, dissolved inorganic carbon (DIC) and its isotopic composition (δ13C) were conducted in the Dead Sea, from surface down to the bottom of the lake (290 m). Mass balance calculations conducted for the period 1993-2013 show that while inventories of conservative ions such as Mg2+ remained constant, the net DIC inventory of the lake decreased by ∼10%. DIC supply to the lake during this period, however, amounted to ∼10% of lake's inventory indicating that during 20 years, the lake lost ∼20% of its 1993s inventory. Compilation of historical data with our data shows that during the past two decades the lake's low DIC (∼1 mmol kg-1) and very high PCO2 (1800 ppm V) remained relatively constant, suggesting that a quasi-steady-state situation prevails. In spite of the surprisingly stable DIC and CO2 concentrations, during this 20 year period δ13CDIC increased significantly, from 1.4‰ to 2.7‰. An isotopic

  4. Constraints on evaporation and dilution of terminal, hypersaline lakes under negative water balance: The Dead Sea, Israel

    Science.gov (United States)

    Zilberman, Tami; Gavrieli, Ittai; Yechieli, Yoseph; Gertman, Isaac; Katz, Amitai

    2017-11-01

    The response of hypersaline terminal lakes to negative water balance was investigated by studying brines evaporating to extreme salinities in sinkholes along the western coast of the Dead Sea and during on-site evaporation experiments of the Dead Sea brine. Density and temperature were determined in the field and all samples were analyzed for their major and a few minor solutes. The activity of H2O (aH2O) in the brines was calculated, and the degree of evaporation (DE) was established using Sr2+as a conservative solute. The relations between density and water activity were obtained by polynomial regression, and the relation between the lake's volume and level was established using Hall's (1996) hypsographic model for the Dead Sea basin. Relating the results to the modern, long-term relative humidity (RH) over the basin shows that (a) The lowermost attainable level of a terminal lake undergoing evaporation with no inflow is dictated by the median RH; this level represents equilibrium between the brine's aH2O and RH; (b) Small, saline water bodies with high surface to volume ratios (A/V), such as the hypersaline brines in the sinkholes, are very sensitive to short term changes in RH; in these, the brines' aH2O closely follows the seasonal changes; (c) the level decline of the Dead Sea due to evaporation under present climatic conditions and assuming no inflow to the lake may continue down to 516-537 m below mean sea level (bmsl), corresponding to a water activity range of 0.46-0.39 in its brine, in equilibrium with the overlying relative air humidity; this suggests that the lake level cannot drop more than ∼100 m from its present level; and (d) The maximum RH values that existed over the precursor lake of the Dead Sea (Lake Lisan) during geologically reconstructed minima levels can be similarly calculated.

  5. Dead Sea Scrolls

    Science.gov (United States)

    1994-01-01

    A consortium of researchers from Jet Propulsion Laboratory and three other organizations used charged coupled devices (CCDs) and other imaging enhancement technology to decipher previously unreadable portions of the Dead Sea Scrolls. The technique has potentially important implications for archeology.

  6. Rates and cycles of microbial sulfate reduction in the hyper-saline Dead Sea over the last 200 kyrs from sedimentary d34S and d18O(SO4)

    Science.gov (United States)

    Torfstein, Adi; Turchyn, Alexandra V.

    2017-08-01

    We report the d34S and d18O(SO4) values measured in gypsum, pyrite, and elemental sulfur through a 456-m thick sediment core from the center of the Dead Sea, representing the last 200 kyrs, as well as from the exposed glacial outcrops of the Masada M1 section located on the margins of the modern Dead Sea. The results are used to explore and quantify the evolution of sulfur microbial metabolism in the Dead Sea and to reconstruct the lake’s water column configuration during the late Quaternary. Layers and laminae of primary gypsum, the main sulfur-bearing mineral in the sedimentary column, display the highest d34S and d18O(SO4) in the range of 13-28‰ and 13-30‰, respectively. Within this group, gypsum layers deposited during interglacials have lower d34S and d18O(SO4) relative to those associated with glacial or deglacial stages. The reduced sulfur phases, including chromium reducible sulfur, and secondary gypsum crystals are characterized by extremely low d34S in the range of -27 to +7‰. The d18O(SO4) of the secondary gypsum in the M1 outcrop ranges from 8 to 14‰. The relationship between d34S and d18O(SO4) of primary gypsum suggests that the rate of microbial sulfate reduction was lower during glacial relative to interglacial times. This suggests that the freshening of the lake during glacial wet intervals, and the subsequent rise in sulfate concentrations, slowed the rate of microbial metabolism. Alternatively, this could imply that sulfate-driven anaerobic methane oxidation, the dominant sulfur microbial metabolism today, is a feature of the hypersalinity in the modern Dead Sea. Sedimentary sulfides are quantitatively oxidized during epigenetic exposure, retaining the lower d34S signature; the d18O(SO4) of this secondary gypsum is controlled by oxygen atoms derived equally from atmospheric oxygen and from water, which is likely a unique feature in this hyperarid environment.

  7. Rates and Cycles of Microbial Sulfate Reduction in the Hyper-Saline Dead Sea over the Last 200 kyrs from Sedimentary δ34S and δ18O(SO4

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    Adi Torfstein

    2017-08-01

    Full Text Available We report the δ34S and δ18O(SO4 measured in gypsum, pyrite, and elemental sulfur through a 456-m thick sediment core from the center of the Dead Sea, representing the last ~200 kyrs, as well as from the exposed glacial outcrops of the Masada M1 section located on the margins of the modern Dead Sea. The results are used to explore and quantify the evolution of sulfur microbial metabolism in the Dead Sea and to reconstruct the lake's water column configuration during the late Quaternary. Layers and laminae of primary gypsum, the main sulfur-bearing mineral in the sedimentary column, display the highest δ34S and δ18O(SO4 in the range of 13–28 and 13–30‰, respectively. Within this group, gypsum layers deposited during interglacials display lower δ34S and δ18O(SO4 relative to those associated with glacial or deglacial stages. The reduced sulfur phases, including chromium reducible sulfur, and secondary gypsum crystals are characterized by extremely low δ34S in the range of −27 to +7‰. The δ18O(SO4 of the secondary gypsum in the M1 outcrop ranges from 8 to 14‰. The relationship between δ34S and δ18O(SO4 of primary gypsum suggests that the rate of microbial sulfate reduction was lower during glacial relative to interglacial times. This suggests that the freshening of the lake during glacial wet intervals, and the subsequent rise in sulfate concentrations, slowed the rate of microbial metabolism. Alternatively, this could imply that sulfate-driven anaerobic methane oxidation, the dominant sulfur microbial metabolism today, is a feature of the hypersalinity in the modern Dead Sea. Sedimentary sulfides are quantitatively oxidized during epigenetic exposure, retaining the lower δ34S signature; the δ18O(SO4 of this secondary gypsum is controlled by oxygen atoms derived equally from atmospheric oxygen and from water, which is likely a unique feature in this hyperarid environment.

  8. The Dead Sea

    Science.gov (United States)

    2006-01-01

    The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining

  9. Dead sea asphalts: historical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Nissenbaum, A.

    1978-05-01

    Asphalts are present in the Dead Sea basin in three forms: (1) huge blocks, up to 100 tons in weight, composed of extremely pure (>99.99%) solid asphalt occasionally found floating on the lake, (2) veins, seepages, and cavity and fissure fillings in Lower Cretaceous to Holocene rocks, and (3) ozocerite veins on the eastern shore of the lake. Dead Sea asphalts probably have been documented over a longer period of time than any other hydrocarbon deposit--from antiquity to the 19th century. Major uses of asphalt from the Dead Sea have been as an ingredient in the embalming process, for medicinal purposes, for fumigation, and for agriculture. The first known war for control of a hydrocarbon deposit was in the Dead Sea area in 312 B.C. between the Seleucid Syrians and the Nabatean Arabs who lived around the lake. Surface manifestations of asphalt are linked closely to tectonic activity. In the lake itself, the asphalt is associated with diapirs During certain historic periods, tectonic and diapiric activity caused frequent liberation to the Dead Sea surface of semiliquid asphalt associated with large amounts of hydrogen sulfide gas. When the tectonic activity was attenuated, as in the 19th and 20th centuries, the rate of asphalt seepage to the bottom sediments of the Dead Sea was much slower and the asphalt solidified on the lake bottom. The release of asphalt to the surface became much more sporadic, and may have resulted in part from earthquakes. Thus, future asphalt prospecting in the Dead Sea area should be conducted along the boundaries of diapirs or their associated faults.

  10. Microenvironments of reduced salinity harbour biofilms in Dead Sea underwater springs

    NARCIS (Netherlands)

    Häusler, S.; Noriega-Ortega, B.E.; Polerecky, L.|info:eu-repo/dai/nl/370827929; Meyer, V.; de Beer, D.; Ionescu, D.

    2014-01-01

    The Dead Sea is a hypersaline lake where only few types of organisms can grow. Recently, abundant and diverse microbial life was discovered in biofilms covering rocks and permeable sediments around underwater freshwater springs and seeps. We used a newly developed salinity mini-sensor (spatial

  11. Antimicrobial properties of Dead Sea black mineral mud.

    Science.gov (United States)

    Ma'or, Zeev; Henis, Yigal; Alon, Yaacov; Orlov, Elina; Sørensen, Ketil B; Oren, Aharon

    2006-05-01

    The unique, black, hypersaline mud mined from the Dead Sea shores is extensively used in mud packs, masks, and topical body and facial treatments in spas surrounding the lake, and in cosmetic preparations marketed worldwide, but little is known about its antimicrobiological properties. We performed detailed microbial and chemical analysis of Dead Sea mineral mud compounded in dermatological and cosmetic preparations. Using conventional bacteriological media (with or without salt augmentation), we found surprisingly low numbers of colony-forming microorganisms in the mud. The highest counts (up to 20,000 colonies per gram, mostly consisting of endospore-forming bacteria) were obtained on sheep blood agar. Test microorganisms (i.e. Escherichia coli, Staphylococcus aureus, Propionibacterium acnes, Candida albicans) rapidly lost their viability when added to the mud. Zones of growth inhibition were observed around discs of Dead Sea mud placed on agar plates inoculated with Candida or with Propionibacterium, but not with Staphylococcus or Escherichia. The effect was also found when the mud was sterilized by gamma irradiation. Using (35)S-labeled sulfate as a tracer, bacterial dissimilatory sulfate reduction could be demonstrated at a low rate (0.13 +/- 0.03 nmol/cm(3).d). The antibacterial properties of Dead Sea mud are probably owing to chemical and/or physical phenomena. Possible modes of antimicrobial action of the mud in relation to its therapeutic properties are discussed.

  12. Raising the Dead without a Red Sea-Dead Sea project? Hydro-economics and governance

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    D. E. Rosenberg

    2011-04-01

    Full Text Available Seven decades of extractions have dramatically reduced Jordan River flows, lowered the Dead Sea level, opened sink holes, and caused other environmental problems. The fix Jordan, Israel, and the Palestinians propose would build an expensive multipurpose conveyance project from the Red Sea to the Dead Sea that would also generate hydropower and desalinate water. This paper compares the Red-Dead project to alternatives that may also raise the Dead Sea level. Hydro-economic model results for the Jordan-Israel-Palestinian inter-tied water systems show two restoration alternatives are more economically viable than the proposed Red-Dead project. Many decentralized new supply, wastewater reuse, conveyance, conservation, and leak reduction projects and programs in each country can together increase economic benefits and reliably deliver up to 900 MCM yr−1 to the Dead Sea. Similarly, a smaller Red-Dead project that only generates hydropower can deliver large flows to the Dead Sea when the sale price of generated electricity is sufficiently high. However, for all restoration options, net benefits fall and water scarcity rises as flows to the Dead Sea increase. This finding suggests (i each country has no individual incentive to return water to the Dead Sea, and (ii outside institutions that seek to raise the Dead must also offer countries direct incentives to deliver water to the Sea besides building the countries new infrastructure.

  13. Raising the Dead without a Red Sea-Dead Sea project? Hydro-economics and governance

    Science.gov (United States)

    Rosenberg, D. E.

    2011-04-01

    Seven decades of extractions have dramatically reduced Jordan River flows, lowered the Dead Sea level, opened sink holes, and caused other environmental problems. The fix Jordan, Israel, and the Palestinians propose would build an expensive multipurpose conveyance project from the Red Sea to the Dead Sea that would also generate hydropower and desalinate water. This paper compares the Red-Dead project to alternatives that may also raise the Dead Sea level. Hydro-economic model results for the Jordan-Israel-Palestinian inter-tied water systems show two restoration alternatives are more economically viable than the proposed Red-Dead project. Many decentralized new supply, wastewater reuse, conveyance, conservation, and leak reduction projects and programs in each country can together increase economic benefits and reliably deliver up to 900 MCM yr-1 to the Dead Sea. Similarly, a smaller Red-Dead project that only generates hydropower can deliver large flows to the Dead Sea when the sale price of generated electricity is sufficiently high. However, for all restoration options, net benefits fall and water scarcity rises as flows to the Dead Sea increase. This finding suggests (i) each country has no individual incentive to return water to the Dead Sea, and (ii) outside institutions that seek to raise the Dead must also offer countries direct incentives to deliver water to the Sea besides building the countries new infrastructure.

  14. Raising the dead without a Red Sea-Dead Sea canal? Hydro-economics and governance

    Science.gov (United States)

    Rosenberg, D. E.

    2010-12-01

    Seven decades of extractions have dramatically reduced Jordan River flows, lowered the Dead Sea level, opened sink holes, and caused other environmental problems. The fix Jordan, Israel, and the Palestinians propose would build an expensive multipurpose canal from the Red Sea to the Dead Sea that would also generate hydropower and desalinated water. This paper compares the Red-Dead project to alternatives that may also raise the Dead Sea level. Hydro-economic model results for the Jordan-Israel-Palestinian inter-tied water systems show two restoration alternatives are more economically viable than the proposed Red-Dead project. Many decentralized new supply, wastewater reuse, conveyance, conservation, and leak reduction projects and programs in each country can together increase economic benefits and reliably deliver up to 900 MCM/year to the Dead Sea. Similarly, a smaller Red-Dead project that only generates hydropower can deliver large flows to the Dead Sea when the sale price of generated electricity is sufficiently high. However, for all restoration options, net benefits fall and water scarcity rises as flows to the Dead Sea increase. This finding suggests (i) each country has no individual incentive to return water to the Dead Sea, and (ii) outside institutions that seek to raise the Dead must also offer countries direct incentives to deliver water to the Sea besides building the countries new infrastructure.

  15. Freshening of the Dead Sea during the Last Glacial Revealed By Porewater Composition in ICDP Dead Sea Deep-Drill

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    Lazar, B.; Sivan, O.; Yechieli, Y.; Levy, E. J.; Antler, G.; Gavrieli, I.; Stein, M.

    2014-12-01

    The geological evolution of the brine lakes that filled the Dead Sea basin has been extensively studied on the sedimentary exposures and drill cores on the Sea marginal terraces of the modern Dead Sea. These geological sections documented the history of the epilimnion (upper brine) of the hypersaline lake during its high stands periods. The cores drilled during 2011 by ICDP in the deep basin of the Dead Sea at water depth of 300 m provided the first opportunity to study the history of the deepest part of the hypolimnion (deep brine) by measuring the chemical and isotopic composition of pore-fluids. The vertical profiles of chloride (Cl-) sodium (Na+) and oxygen isotopes (δ18O) in the pore brines revealed a substantial decrease in salinity of the hypolimnion during the high stand of the last glacial Lake Lisan (the last glacial predecessor of the modern Dead Sea), particularly during MIS2 (~31-17 ka BP). Diffusion-deposition model indicated that Cl- concentration of the deep hypolimnetic brine decreased gradually to less than 2/3 of its present value. The δ18O at the same time increased to maximum of ~7‰ (3‰ higher than today). Beforehand, during the interglacial and later during the post-glacial and the Holocene the Cl- concentrations and δ18O values were similar to those of the modern Dead Sea. The slow dilution of the deep Ca-chloride brine was caused probably by continuous turbulent mixing of the hypolimnion with the less saline high δ18O epilimnetic brine, across the epilimnion/hypolimnion interface (EHI). The increase in δ18O during the salinity decrease of Lake Lisan was a result of evaporative fractionation of the less saline epilimnetic brine. The post-glacial δ18O decrease while salinity increased is attributed to the "reversed" δ18O fractionation during evaporation of very high salinity brine. Increase in the Na/Cl ratio due to dissolution of halite without reaching halite saturation was also observed during the freshening period.

  16. Dead sea transform fault system reviews

    CERN Document Server

    Garfunkel, Zvi; Kagan, Elisa

    2014-01-01

    The Dead Sea transform is an active plate boundary connecting the Red Sea seafloor spreading system to the Arabian-Eurasian continental collision zone. Its geology and geophysics provide a natural laboratory for investigation of the surficial, crustal and mantle processes occurring along transtensional and transpressional transform fault domains on a lithospheric scale and related to continental breakup. There have been many detailed and disciplinary studies of the Dead Sea transform fault zone during the last?20 years and this book brings them together.This book is an updated comprehensive coverage of the knowledge, based on recent studies of the tectonics, structure, geophysics, volcanism, active tectonics, sedimentology and paleo and modern climate of the Dead Sea transform fault zone. It puts together all this new information and knowledge in a coherent fashion.

  17. Fungal life in the dead sea.

    Science.gov (United States)

    Oren, Aharon; Gunde-Cimerman, Nina

    2012-01-01

    The waters of the Dead Sea currently contain about 348 g/l salts (2 M Mg(2+), 0.5 M Ca(2+), 1.5 M Na(+), 0.2 M K(+), 6.5 M Cl(-), 0.1 M Br(-)). The pH is about 6.0. After rainy winters the surface waters become diluted, triggering development of microbial blooms. The 1980 and 1992 blooms were dominated by the unicellular green alga Dunaliella and red Archaea. At least 70 species (in 26 genera) of Oomycota (Chromista), Mucoromycotina, Ascomycota, and Basidiomycota (Fungi) were isolated from near-shore localities and offshore stations, including from deep waters. Aspergillus and Eurotium were most often recovered. Aspergillus terreus, A. sydowii, A. versicolor, Eurotium herbariorum, Penicillium westlingii, Cladosporium cladosporioides, C. sphaerospermum, C. ramnotellum, and C. halotolerans probably form the stable core of the community. The species Gymnascella marismortui may be endemic. Mycelia of Dead Sea isolates of A. versicolor and Chaetomium globosum remained viable for up to 8 weeks in Dead Sea water; mycelia of other species survived for many weeks in 50% Dead Sea water. Many isolates showed a very high tolerance to magnesium salts. There is no direct proof that fungi contribute to the heterotrophic activity in the Dead Sea, but fungi may be present at least locally and temporarily, and their enzymatic activities such as amylase, protease, and cellulase may play a role in the lake's ecosystem.

  18. Genomic adaptations of the halophilic Dead Sea filamentous fungus Eurotium rubrum.

    Science.gov (United States)

    Kis-Papo, Tamar; Weig, Alfons R; Riley, Robert; Peršoh, Derek; Salamov, Asaf; Sun, Hui; Lipzen, Anna; Wasser, Solomon P; Rambold, Gerhard; Grigoriev, Igor V; Nevo, Eviatar

    2014-05-09

    The Dead Sea is one of the most hypersaline habitats on Earth. The fungus Eurotium rubrum (Eurotiomycetes) is among the few species able to survive there. Here we highlight its adaptive strategies, based on genome analysis and transcriptome profiling. The 26.2 Mb genome of E. rubrum shows, for example, gains in gene families related to stress response and losses with regard to transport processes. Transcriptome analyses under different salt growth conditions revealed, among other things differentially expressed genes encoding ion and metabolite transporters. Our findings suggest that long-term adaptation to salinity requires cellular and metabolic responses that differ from short-term osmotic stress signalling. The transcriptional response indicates that halophilic E. rubrum actively counteracts the salinity stress. Many of its genes encode for proteins with a significantly higher proportion of acidic amino acid residues. This trait is characteristic of the halophilic prokaryotes as well, supporting the theory of convergent evolution under extreme hypersaline stress.

  19. Microbial and Chemical Characterization of Underwater Fresh Water Springs in the Dead Sea

    Science.gov (United States)

    Ionescu, Danny; Siebert, Christian; Polerecky, Lubos; Munwes, Yaniv Y.; Lott, Christian; Häusler, Stefan; Bižić-Ionescu, Mina; Quast, Christian; Peplies, Jörg; Glöckner, Frank Oliver; Ramette, Alban; Rödiger, Tino; Dittmar, Thorsten; Oren, Aharon; Geyer, Stefan; Stärk, Hans-Joachim; Sauter, Martin; Licha, Tobias; Laronne, Jonathan B.; de Beer, Dirk

    2012-01-01

    Due to its extreme salinity and high Mg concentration the Dead Sea is characterized by a very low density of cells most of which are Archaea. We discovered several underwater fresh to brackish water springs in the Dead Sea harboring dense microbial communities. We provide the first characterization of these communities, discuss their possible origin, hydrochemical environment, energetic resources and the putative biogeochemical pathways they are mediating. Pyrosequencing of the 16S rRNA gene and community fingerprinting methods showed that the spring community originates from the Dead Sea sediments and not from the aquifer. Furthermore, it suggested that there is a dense Archaeal community in the shoreline pore water of the lake. Sequences of bacterial sulfate reducers, nitrifiers iron oxidizers and iron reducers were identified as well. Analysis of white and green biofilms suggested that sulfide oxidation through chemolitotrophy and phototrophy is highly significant. Hyperspectral analysis showed a tight association between abundant green sulfur bacteria and cyanobacteria in the green biofilms. Together, our findings show that the Dead Sea floor harbors diverse microbial communities, part of which is not known from other hypersaline environments. Analysis of the water’s chemistry shows evidence of microbial activity along the path and suggests that the springs supply nitrogen, phosphorus and organic matter to the microbial communities in the Dead Sea. The underwater springs are a newly recognized water source for the Dead Sea. Their input of microorganisms and nutrients needs to be considered in the assessment of possible impact of dilution events of the lake surface waters, such as those that will occur in the future due to the intended establishment of the Red Sea−Dead Sea water conduit. PMID:22679498

  20. Spatio-temporal development of sinkholes on the eastern shore of the Dead Sea

    Science.gov (United States)

    Holohan, Eoghan; Saberi, Leila; Al-Halbouni, Djamil; Sawarieh, Ali; Closson, Damien; Alrshdan, Hussam; Walter, Thomas; Dahm, Torsten

    2017-04-01

    The ongoing, largely anthropogenically-forced decline of the Dead Sea is associated with the most prolific development of sinkholes worldwide. The fall in hydrological base level since the 1960s is thought to enable relatively fresh ground waters to dissolve underground salt deposits that were previously in equilibrium with hypersaline Dead Sea brine. Sinkhole development in response to this dissolution began in the 1980s and is still ongoing; it represents a significant geohazard in the Dead Sea region. We present new research undertaken within the Dead Sea Research Venue (DESERVE) on the spatio-temporal evolution of the main sinkhole-affected site on the Eastern shore of the Dead Sea, at Ghor Al-Haditha in Jordan. Our data set includes optical satellite imagery, aerial survey photographs and drone-based photogrammetric surveys with high spatial (sinkhole sites. Our analysis shows that there are now over 800 sinkholes at Ghor al-Haditha. Sinkholes initiated as spatially distinct clusters in the late 1980's to early 1990s. While some clusters have since become inactive, most have expanded and merged with time. New clusters have also developed, mainly in the more recently exposed north of the area. With the retreat of the Dead Sea, the roughly coastline-parallel zone of sinkhole formation has expanded unevenly but systematically seawards. Such a seaward migration of sinkhole formation is predicted from hydrogeological theory, but as yet not consistently observed elsewhere at the Dead Sea. The rate of sinkhole formation at Ghor Haditha accelerated markedly during the late 2000s to a peak of about 100 per year in 2009. Similar accelerations are observed on the western shore, but differ in timing. The rate of sinkhole formation on the Eastern shore has since declined to about 50 per year. Such differences in the overall spatio-temporal evolution of sinkholes on the eastern and western shores of the Dead Sea likely highlights the important role of local hydrogeological

  1. Modelling chemistry over the Dead Sea: bromine and ozone chemistry

    Directory of Open Access Journals (Sweden)

    R. von Glasow

    2009-07-01

    Full Text Available Measurements of O3 and BrO concentrations over the Dead Sea indicate that Ozone Depletion Events (ODEs, widely known to happen in polar regions, are also occuring over the Dead Sea due to the very high bromine content of the Dead Sea water. However, we show that BrO and O3 levels as they are detected cannot solely be explained by high Br levels in the Dead Sea water and the release of gas phase halogen species out of sea borne aerosol particles and their conversion to reactive halogen species. It is likely that other sources for reactive halogen compounds are needed to explain the observed concentrations for BrO and O3. To explain the chemical mechanism taking place over the Dead Sea leading to BrO levels of several pmol/mol we used the one-dimensional model MISTRA which calculates microphysics, meteorology, gas and aerosol phase chemistry. We performed pseudo Lagrangian studies by letting the model column first move over the desert which surrounds the Dead Sea region and then let it move over the Dead Sea itself. To include an additional source for gas phase halogen compounds, gas exchange between the Dead Sea water and the atmosphere is treated explicitly. Model calculations indicate that this process has to be included to explain the measurements.

  2. Evaporation estimates from the Dead Sea and their implications on its water balance

    Science.gov (United States)

    Oroud, Ibrahim M.

    2011-12-01

    The Dead Sea (DS) is a terminal hypersaline water body situated in the deepest part of the Jordan Valley. There is a growing interest in linking the DS to the open seas due to severe water shortages in the area and the serious geological and environmental hazards to its vicinity caused by the rapid level drop of the DS. A key issue in linking the DS with the open seas would be an accurate determination of evaporation rates. There exist large uncertainties of evaporation estimates from the DS due to the complex feedback mechanisms between meteorological forcings and thermophysical properties of hypersaline solutions. Numerous methods have been used to estimate current and historical (pre-1960) evaporation rates, with estimates differing by ˜100%. Evaporation from the DS is usually deduced indirectly using energy, water balance, or pan methods with uncertainty in many parameters. Accumulated errors resulting from these uncertainties are usually pooled into the estimates of evaporation rates. In this paper, a physically based method with minimum empirical parameters is used to evaluate historical and current evaporation estimates from the DS. The more likely figures for historical and current evaporation rates from the DS were 1,500-1,600 and 1,200-1,250 mm per annum, respectively. Results obtained are congruent with field observations and with more elaborate procedures.

  3. Dead Sea drawdown and monsoonal impacts in the Levant during the last interglacial

    Science.gov (United States)

    Torfstein, Adi; Goldstein, Steven L.; Kushnir, Yochanan; Enzel, Yehouda; Haug, Gerald; Stein, Mordechai

    2015-02-01

    Sediment cores recovered by the Dead Sea Deep Drilling Project (DSDDP) from the deepest basin of the hypersaline, terminal Dead Sea (lake floor at ∼725 m below mean sea level) reveal the detailed climate history of the lake's watershed during the last interglacial period (Marine Isotope Stage 5; MIS5). The results document both a more intense aridity during MIS5 than during the Holocene, and the moderating impacts derived from the intense MIS5e African Monsoon. Early MIS5e (∼133-128 ka) was dominated by hyperarid conditions in the Eastern Mediterranean-Levant, indicated by thick halite deposition triggered by a lake-level drop. Halite deposition was interrupted however, during the MIS5e peak (∼128-122 ka) by sequences of flood deposits, which are coeval with the timing of the intense precession-forced African monsoon that generated Mediterranean sapropel S5. A subsequent weakening of this humidity source triggered extreme aridity in the Dead Sea watershed and resulting in the biggest known lake level drawdown in its history, reflected by the deposition of thick salt layers, and a capping pebble layer corresponding to a hiatus at ∼116-110 ka. The DSDDP core provides the first evidence for a direct association of the African monsoon with mid subtropical latitude climate systems effecting the Dead Sea watershed. Combined with coeval deposition of Arabia and southern Negev speleothems, Arava travertines, and calcification of Red Sea corals, the evidence points to a climatically wet corridor that could have facilitated homo sapiens migration "out of Africa" during the MIS5e peak. The hyperaridity documented during MIS5e may provide an important analogue for future warming of arid regions of the Eastern Mediterranean-Levant.

  4. Long-term freshening of the Dead Sea brine revealed by porewater Cl- and δO18 in ICDP Dead Sea deep-drill

    Science.gov (United States)

    Lazar, B.; Sivan, O.; Yechieli, Y.; Levy, E. J.; Antler, G.; Gavrieli, I.; Stein, M.

    2014-08-01

    The geological evolution of the unique Dead Sea Ca-chloride brine has been the focus of many research efforts for several decades. These studies relied on the information obtained from sedimentary exposures of the marginal terraces of the modern Dead Sea, mostly documenting the history of the surface lake brine during its high stands periods. The present study is the first attempt to establish the history of the deepest part of the lake by direct measurements of the chemical and isotopic composition of pore-fluids that were extracted from cores drilled during 2011 by ICDP in the deep basin of the Dead Sea at water depth of 300 m. The vertical profiles of chloride (Cl-) and oxygen isotopes (δO18) in pore brines reveal a substantial decrease in the salinity of the hyper-saline lake during the last glacial and particularly during MIS2 (∼31-17 ka BP). The Cl- concentration of the deep brine in the lake decreased gradually, reaching a minimum of less than 2/3 of its present value while the δO18 increased to maximum of ∼7‰ (3‰ higher than today). The low Cl- indicates significant dilution of the bottom water mass (hypolimnion) of Lake Lisan (the last glacial predecessor of the modern Dead Sea) during its highest stand period. Beforehand, during the interglacial and later during the post-glacial and the Holocene the Cl- concentrations and δO18 values were similar to those of the modern Dead Sea. The slow dilution of the deep Ca-chloride brine was caused probably by continuous turbulent mixing of the hypolimnion with the less saline high δO18 epilimnetic brine, across the epilimnion/hypolimnion interface (EHI). While the increase in δO18 during the salinity decrease of Lake Lisan is a result of “normal” evaporation of the less saline epilimnetic brine, the post-glacial δO18 decrease (contemporaneous with salinity increase) is attributed to the “reversed” behavior of δO18 during evaporation of high salinity brine. During the long freshening period the

  5. Long-term freshening of the Dead Sea brine during the last glacial revealed by porewater Cl- and δ18O in ICDP Dead Sea deep-drill

    Science.gov (United States)

    Lazar, Boaz; Sivan, Orit; Yechieli, Yosseph; Levi, Elan; Antler, Gilad; Gavrieli, Ittai; Stein, Mordechai

    2014-05-01

    The geological evolution of the unique Dead Sea Ca-chloride brine has been the focus of many research efforts for several decades. These studies relied on the information obtained from sedimentary exposures of the marginal terraces of the modern Dead Sea, mostly documenting the history of the surface lake brine during its high stands periods. The present study is the first attempt to establish the history of the deepest part of the lake by direct measurements of the chemical and isotopic composition of pore-fluids that were extracted from cores drilled during 2011 by ICDP in the deep basin of the Dead Sea at water depth of 300 m. The vertical profiles of chloride (Cl-) and oxygen isotopes (δ18O) in pore brines reveal a substantial decrease in the salinity of the hyper-saline lake during the last glacial and particularly during MIS2 (~31-17 ka BP). The Cl- concentration of the deep brine in the lake decreased gradually reaching a minimum of less than 2/3 of its present value while the δ18O on the same time increased to maximum of ~7o (3o higher than today). The low Cl- indicates significant dilution of the bottom water mass (hypolimnion) of Lake Lisan (the last glacial predecessor of the modern Dead Sea) during its highest stand period. Beforehand, during the interglacial and later during the post-glacial and the Holocene the Cl- concentrations and δ18O values were similar to those of the modern Dead Sea. The slow dilution of the deep Ca-chloride brine was caused probably by continuous turbulent mixing of the hypolimnion with the less saline high δ18O epilimnetic brine, across the epilimnion/hypolimnion interface (EHI). While the increase in δ18O during the salinity decrease of Lake Lisan is a result of 'normal' evaporation of the less saline epilimnetic brine, the post-glacial δ18O decrease (contemporaneous with salinity increase) is attributed to the 'backward' behavior of δ18O during evaporation of high salinity brine. During the long freshening period the

  6. Sulfate-reducing prokaryotic communities in two deep hypersaline anoxic basins in the Eastern Mediterranean deep sea

    NARCIS (Netherlands)

    van der Wielen, Paul W. J. J.; Heljs, Sander K.

    In the Eastern Mediterranean Sea, deep hypersaline anoxic basins (DHABs) and deep-sea sediment contain anoxic environments where sulfate reduction is an important microbial metabolic process. The objective of this study was to characterize the sulfate-reducing community in the brine and interface of

  7. Scale-free distribution of Dead Sea sinkholes: Observations and modeling

    Science.gov (United States)

    Yizhaq, H.; Ish-Shalom, C.; Raz, E.; Ashkenazy, Y.

    2017-05-01

    There are currently more than 5500 sinkholes along the Dead Sea in Israel. These were formed due to the dissolution of subsurface salt layers as a result of the replacement of hypersaline groundwater by fresh brackish groundwater. This process has been associated with a sharp decline in the Dead Sea water level, currently more than 1 m/yr, resulting in a lower water table that has allowed the intrusion of fresher brackish water. We studied the distribution of the sinkhole sizes and found that it is scale free with a power law exponent close to 2. We constructed a stochastic cellular automata model to understand the observed scale-free behavior and the growth of the sinkhole area in time. The model consists of a lower salt layer and an upper soil layer in which cavities that develop in the lower layer lead to collapses in the upper layer. The model reproduces the observed power law distribution without involving the threshold behavior commonly associated with criticality.

  8. Scale-free distribution of Dead Sea sinkholes--observations and modeling

    CERN Document Server

    Yizhaq, Hezi; Raz, Eli; Ashkenazy, Yosef

    2016-01-01

    There are currently more than 5500 sinkholes along the Dead Sea in Israel. These were formed due to dissolution of subsurface salt layers as a result of the replacement of hypersaline groundwater by fresh brackish groundwater. This process was associated with a sharp decline in the Dead Sea level, currently more than one meter per year, resulting in a lower water table that has allowed the intrusion of fresher brackish water. We studied the distribution of the sinkholes sizes and found that it is scale-free with a power-law exponent close to 2. We constructed a stochastic cellular automata model to understand the observed scale-free behavior and the growth of the sinkholes area in time. The model consists of a lower salt layer and an upper soil layer in which cavities that develop in the lower layer lead to collapses in the upper layer. The model reproduces the observed power-law distribution without entailing the threshold behavior commonly associated with criticality.

  9. Organic Proxy Disturbance in the Dead Sea Basin at the Beginning of the Holocene

    Science.gov (United States)

    Thomas, C.; Ariztegui, D.; Levy, E. J.; Antler, G.; Sivan, O.; Yechieli, Y.; Gavrieli, I.; Turchyn, A. V.; Stein, M.

    2014-12-01

    Paleoenvironmental reconstruction is among the main targets of the International Continental Drilling Program (ICDP)-sponsored Dead Sea Deep Drilling Project (DSDDP). Around 450 meters of core were retrieved and currently several multi-disciplinary studies are being performed in this almost continuous sedimentary record. Careful attention has been directed to understanding the microbial communities living in the hypersaline sediment and the potential impact they might have on biogeochemical cycles both in the lake and in the Dead Sea precursors. Studies have highlighted the potential for microbial activity in the lake, in spite of its hypersalinity, and the putative influence of microbial communities on the geochemical record, especially with respect to reconstruction of the carbon and sulfur cycles. More recently, geomicrobiological and geochemical studies with samples obtained during the DSDDP have revealed the potential for methane production (methanogenesis) in the subsurface; this can greatly impact the carbon isotope record in the subsurface and could skew any paleoenvironmental interpretation. By combining carbon, sulfur and oxygen isotopes from the interstitial pore water and the surrounding sediment, including a lithological facies study and biomarker analysis, we highlight that the period following massive gypsum precipitation in the Dead Sea, at the onset of the Holocene, has been subject to major changes. At this time, variations in the level of the lake, accompanied by water mixing, have supposedly initiated intense microbial activity in the paleo-water column and probably within the sediment after its burial, as indicated by specific authigenic Fe-S mineralizations. Sulfur isotope evidence from the pore fluids suggests that these Fe-S precipitations may be microbial in nature. While no DNA could be extracted from this interval to allow a microbial diversity study, the retrieval, among others, of non-isoprenoid macrocyclic glycerol diethers potentially

  10. Life and survival in a magnesium chloride brine: the biology of the Dead Sea

    Science.gov (United States)

    Oren, Aharon

    1998-07-01

    The Dead Sea is a hypersaline terminal desert lake. Its water contains about 340 g/l total dissolved salts. Divalent cations dominate in the brine, which presently contains about 1.89 M magnesium and 0.44 M calcium, n addition to about 1.6 M sodium and 0.2 M potassium. The main anions are chloride and bromide. The pH of the brine is about 6.0, and its water activity was estimated at about 0.66. The lake is saturated with respect to sodium chloride. The negative water balance in recent years caused a mass precipitation of halite, with a concomitant increase in the relative concentrations of divalent cations. In spite of the fact that molar concentrations of divalent cations are strongly inhibitory to most halophilic and halotolerant microorganisms, the Dead Sea is inhabited by a variety of microorganisms. These include halophilic Archaea, well adapted to growth at high magnesium concentrations, unicellular green algae and a few species of halophilic Bacteria. Dunaliella, being the sole primary producer in the lake, does not grow in undiluted Dead Sea water. However, when the upper water layers become diluted by more than 10 percent as a result of winter rain floods, mass blooms may develop, followed by mass development of red halophilic Archaea, which thrive on the organic material produced by the algae. During the often prolonged periods between the bloom events, during which the salinity of the brines is high and halite precipitates, a small community of Archaea remained present in a state of little activity, but ready to resume growth as soon as a suitable source of organic material becomes available.

  11. Annual dynamics of halite precipitation in the Dead Sea: In situ observations and their geological implications

    Science.gov (United States)

    Sirota, Ido; enzel, Yehouda; Lensky, Nadav G.

    2017-04-01

    Layered halite sequences deposited in deep basins throughout the geological record. However, analogues of such sequences are commonly studied in sallow environments. Here we study active precipitation of halite layers from the only modern analog for deep, halite-precipitating basin, the hypersaline Dead Sea. In situ observations in the Dead Sea link seasonal thermohaline stratification, halite saturation, and the characteristics of the actively forming halite layers. The spatiotemporal evolution of halite precipitation in the Dead Sea was characterized by means of monthly observations of the i) lake thermohaline stratification (temperature, salinity, and density), ii) degree of halite saturation, and iii) textural evolution of the active halite deposits. We present the observed relationships between textural characteristics of layered halite deposits (i.e. grain size, consolidation, and roughness) and the degree of saturation, which in turn reflected the limnology and hydro-climatology. The lakefloor is divided into two principle environments: A deep, hypolimnetic and a shallow, epilimnetic lakefloor. In the deeper hypolimnetic lakefloor halite continuously precipitates with seasonal variations: (a) during summer, consolidated coarse halite crystals form rough surfaces under slight super-saturation. (b) During winter, unconsolidated, fine halite crystals form smooth seafloor deposits under high supersaturation. The observations also emphasize the thought regarding seasonal alternation of halite crystallization mechanism. The shallow epilimnetic lake floor is highly influenced by the seasonal temperature variations, and by intensive summer dissolution of part of the previous year's halite deposit which results in thin sequences with annual unconformities. This emphasizes the control of temperature seasonality on the precipitated halite layers characteristics. In addition, precipitation of halite in the hypolimnetic floor, on the expense of the dissolution of the

  12. The Dynamics of the Skin Temperature of the Dead Sea

    OpenAIRE

    Roni Nehorai; Nadav Lensky; Steve Brenner; Itamar Lensky

    2013-01-01

    We explored the dynamics of the temperature of the skin layer of the Dead Sea surface by means of in situ meteorological and hydrographic measurements from a buoy located near the center of the lake. The skin temperature is most highly correlated to air temperature (0.93–0.98) in all seasons. The skin temperature is much less correlated to the bulk surface water temperature in the summer (0.80), when the lake is thermally stratified, and uncorrelated in the winter, when the Dead Sea is vertic...

  13. Piecing Together the Past: The Dead Sea Schools.

    Science.gov (United States)

    Ulrich, Eugene; And Others

    1995-01-01

    Illustrates the astonishing coordination of archaeological and scholarly activities surrounding the Dead Sea Scrolls. First discovered by Bedouin nomads in 1947, the Scrolls consist of a few complete manuscripts and over 80,000 fragments. Discusses the early Christian sect that produced the Scrolls, and provides current perspectives on the…

  14. The relevance of the Dead Sea scrolls for New Testament ...

    African Journals Online (AJOL)

    The article demonstrates why the Dead Sea Scrolls are important for NT scholarship. After a sketch of the main periods of Qumran research, the author discusses four patterns of relating Qumran with the NT which he considers problematic. Neither was the Qumran community a prototype of Early Christianity, nor do Qumran ...

  15. Literary Genres in Poetic Texts from the Dead Sea Scrolls

    Science.gov (United States)

    Pickut, William Douglas

    2017-01-01

    Among the texts of the Dead Sea Scrolls, there are four literary compositions that bear the superscriptional designations shir and mizmor. These designations correspond directly to superscriptional designations provided many times in both the now-canonical Psalter and the various witnesses to those texts unearthed at Qumran. On its face, this fact…

  16. Stylistic Variation In Three English Translations Of The Dead Sea ...

    African Journals Online (AJOL)

    Since the discovery of the Dead Sea Scrolls in 1947 different English translations were published. In this article the stylistic variation of three of these translations are analysed. It is suggested that the issue of stylistic variation boils down to linguistically inscribed preference in the choice and construction of discourses in the ...

  17. 76 FR 63341 - Culturally Significant Objects Imported for Exhibition Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2011-10-12

    ... for Exhibition Determinations: ``The Dead Sea Scrolls: Life and Faith in Biblical Times'' SUMMARY... objects to be included in the exhibition ``The Dead Sea Scrolls: Life and Faith in Biblical Times...

  18. Spatial and Temporal Variations of Microbial Biodiversity at Hypersaline Microbial Mats

    Science.gov (United States)

    Gulecal, Y.; Unsal, N.; Temel, M.

    2014-12-01

    Hypersaline environments, such as hypersaline lakes are interesting sources with considerable potential for the isolation of extremophile microorganisms adapted to severe conditions. Biodiversity in such lakes (Dead Sea, the Great Salt Lake, the Solar Lake, the Soda Lake) varies due to differences in environmental conditions and specific lake characteristics such as local climate, lake size, water depth and lake water salt composition (Kamekura 1998; Sorokin et al. 2004). In this study area, Acigol Lake is an alkaline (pH:9), hypersaline lake located at Southwest Anatolia in Turkey. The aim of study was to determine the Archaea and Bacteria in microbial mats of hypersaline lacustrine environments. In conclusion, diagnostic biosignatures for methanogens and other archaeal groups within hypersaline microbial mats were identified through genomic DNA and lipid analyses.

  19. 78 FR 16565 - Culturally Significant Objects Imported for Exhibition Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2013-03-15

    ... Culturally Significant Objects Imported for Exhibition Determinations: ``The Dead Sea Scrolls: Life and Faith in Ancient Times'' Formerly Titled ``The Dead Sea Scrolls: Life and Faith in Biblical Times'' ACTION... exhibition ``The Dead Sea Scrolls: Life and Faith in Biblical Times.'' The referenced notice was corrected on...

  20. 78 FR 62354 - Culturally Significant Objects Imported for Exhibition Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2013-10-18

    ... Culturally Significant Objects Imported for Exhibition Determinations: ``The Dead Sea Scrolls: Life and Faith in Ancient Times'' Formerly Titled ``The Dead Sea Scrolls: Life and Faith in Biblical Times'' ACTION... exhibition ``The Dead Sea Scrolls: Life and Faith in Biblical Times.'' The referenced notice was corrected on...

  1. 77 FR 64373 - Culturally Significant Objects Imported for Exhibition Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2012-10-19

    ... Culturally Significant Objects Imported for Exhibition Determinations: ``The Dead Sea Scrolls: Life and Faith in Ancient Times,'' Formerly Titled ``The Dead Sea Scrolls: Life and Faith in Biblical Times... the exhibition ``The Dead Sea Scrolls: Life and Faith in Biblical Times.'' The referenced notice is...

  2. 78 FR 24462 - Culturally Significant Objects Imported for Exhibition; Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2013-04-25

    ... Culturally Significant Objects Imported for Exhibition; Determinations: ``The Dead Sea Scrolls: Life and Faith in Ancient Times'' Formerly Titled ``The Dead Sea Scrolls: Life and Faith in Biblical Times... the exhibition ``The Dead Sea Scrolls: Life and Faith in Biblical Times.'' The referenced notice was...

  3. A Future for the Dead Sea Basin: Water Culture among Israelis, Palestinians and Jordanians

    OpenAIRE

    Lipchin, Clive

    2006-01-01

    The Dead Sea basin plays a major role for regional economic development (industry, tourism and agriculture) in the Middle East. This potential is threatened by the steady disappearance of the Dead Sea. Since around 1930 the water level of the Dead Sea has fallen by about 25 m, about half of this alone in the last 20 years. The Dead Sea is a transboundary resource shared by Israel, the Palestinian Authority and Jordan. The Dead Sea is the terminal point of the Jordan River watershed and as suc...

  4. Modification in amino acids of Dead Sea Scroll Parchments.

    Science.gov (United States)

    Sobel, H; Ajie, H

    1992-12-01

    Fragments of Dead Sea Scroll Parchments were extracted for collagen and subjected to amino acid analysis. In modern parchment samples, 90% or more of the protein could be extracted in hot aqueous solution as collagen. In the ancient specimens, 70% or less was extractable. The hot-solution insoluble material was analyzed for collagen. In the soluble extract, the quantity of tyrosine, histidine, and methionine was reduced. Dityrosine was detected. The need to extend such studies is discussed.

  5. The evolution of the 87Sr/86Sr in the Dead Sea brine: from the Sedom lagoon to Sahara dusts

    Science.gov (United States)

    Stein, Mordechai

    2016-04-01

    The history of water-bodies in the Dead Sea brines commenced with the intrusion of the Sedom lagoon, possibly in the late Neogene and continued with the development of hypersaline and freshwater lakes (e.g. the modern Dead Sea and Sea of Galilee). 87Sr/86Sr ratios in these water-bodies decreased over the past ~ 5-6 Ma from 0.7087-0.7084 in salts deposited in the Sedom lagoon to ~ 0.7080 in modern Dead Sea brine. The 87Sr/86Sr ratios in the salts deposited from Sedom lagoon are significantly lower than those of the contemporaneous late Miocene seawater (~0.709). This difference was attributed to modification of the 87Sr/86Sr ratio in the Sedom lagoon solution by influx of Ca-chloride brines. The brines, in turn were formed by dolomitization of marine limestones of the DSR Cretaceous wall rocks (87Sr/86Sr ~ 0.7075) by the ingressing evaporated seawaters (Stein et al., 2000). After the disconnection of the Sedom lagoon from the open sea freshwater filled the lakes that occupied the Dead Sea basin. The freshwater influx modified the strontium isotope and chemical composition of the brine and provided bicarbonate and sulfate to the lake that led the precipitation of primary aragonite and gypsum. Freshwater that currently enter the lake are characterize by 87Sr/86Sr ~ 0.7081, significantly higher than the Cretaceous carbonates. Settled dust that deposits on the Judea Mountains is composed of calcite and quartz grains and is characterized by 87Sr/86Sr ratios ~ 0.7084. It appears that significant amounts of the strontium that entered the lakes with the freshwater originated from dissolution of the dust calcites. Large amounts of dust were transported from the Sahara desert to the Dead Sea watershed during glacial periods when the Sahara was dry and sea-level was low. The source of the detrital calcites however, is not known. They could be derived from dry paleo-lakes in the Sahara that were previously filled by waters that retained the required strontium isotope

  6. Methanogenic diversity and activity in hypersaline sediments of the centre of the Napoli mud volcano, Eastern Mediterranean Sea.

    Science.gov (United States)

    Lazar, Cassandre Sara; Parkes, R John; Cragg, Barry A; L'Haridon, Stéphane; Toffin, Laurent

    2011-08-01

    Submarine mud volcanoes are a significant source of methane to the atmosphere. The Napoli mud volcano, situated in the brine-impacted Olimpi Area of the Eastern Mediterranean Sea, emits mainly biogenic methane particularly at the centre of the mud volcano. Temperature gradients support the suggestion that Napoli is a cold mud volcano with moderate fluid flow rates. Biogeochemical and molecular genetic analyses were carried out to assess the methanogenic activity rates, pathways and diversity in the hypersaline sediments of the centre of the Napoli mud volcano. Methylotrophic methanogenesis was the only significant methanogenic pathway in the shallow sediments (0-40 cm) but was also measured throughout the sediment core, confirming that methylotrophic methanogens could be well adapted to hypersaline environments. Hydrogenotrophic methanogenesis was the dominant pathway below 50 cm; however, low rates of acetoclastic methanogenesis were also present, even in sediment layers with the highest salinity, showing that these methanogens can thrive in this extreme environment. PCR-DGGE and methyl coenzyme M reductase gene libraries detected sequences affiliated with anaerobic methanotrophs (mainly ANME-1) as well as Methanococcoides methanogens. Results show that the hypersaline conditions in the centre of the Napoli mud volcano influence active biogenic methane fluxes and methanogenic/methylotrophic diversity. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  7. Space Radar Image of Jerusalem and the Dead Sea

    Science.gov (United States)

    1994-01-01

    This space radar image shows the area surrounding the Dead Sea along the West Bank between Israel and Jordan. This region is of major cultural and historical importance to millions of Muslims, Jews and Christians who consider it the Holy Land. The yellow area at the top of the image is the city of Jericho. A portion of the Dead Sea is shown as the large black area at the top right side of the image. The Jordan River is the white line at the top of the image which flows into the Dead Sea. Jerusalem, which lies in the Judaean Hill Country, is the bright, yellowish area shown along the left center of the image. Just below and to the right of Jerusalem is the town of Bethlehem. The city of Hebron is the white, yellowish area near the bottom of the image. The area around Jerusalem has a history of more than 2,000 years of settlement and scientists are hoping to use these data to unveil more about this region's past. The Jordan River Valley is part of an active fault and rift system that extends from southern Turkey and connects with the east African rift zone. This fault system has produced major earthquakes throughout history and some scientists theorize that an earthquake may have caused the fall of Jericho's walls. The Dead Sea basin is formed by active earthquake faulting and contains the lowest place on the Earth's surface at about 400 meters (1,300 feet) below sea level. It was in caves along the northern shore of the Dead Sea that the Dead Sea Scrolls were found in 1947. The blue and green areas are generally regions of undeveloped hills and the dark green areas are the smooth lowlands of the Jordan River valley. This image is 73 kilometers by 45 kilometers (45 miles by 28 miles) and is centered at 31.7 degrees north latitude, 35.4 degrees east longitude. North is toward the upper left. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and vertically received; green is L-band, horizontally

  8. An early first-century earthquake in the Dead Sea

    OpenAIRE

    Williams, J B; Schwab, Markus J.; Achim Brauer;  

    2012-01-01

    This article examines a report in the 27th chapter of the Gospel of Matthew in the New Testament that an earthquake was felt in Jerusalem on the day of the crucifixion of Jesus of Nazareth. We have tabulated a varved chronology from a core from Ein Gedi on the western shore of the Dead Sea between deformed sediments due to a widespread earthquake in 31 BC and deformed sediments due to an early first-century earthquake. The early first-century seismic event has been tentatively assigned a date...

  9. Multiple sensor tracking of submarine groundwater discharge: concept study along the Dead Sea.

    Science.gov (United States)

    Siebert, Christian; Mallast, Ulf; Rödiger, Tino; Ionescu, Danny; Schwonke, Friedhelm; Hall, John K.; Sade, Aharon R.; Pohl, Thomas; Merkel, Broder

    2014-05-01

    As a result of the continuously declining water level of the Dead Sea, vast areas of its former lakebed are exposed. That unconsolidated sequence of clay minerals and evaporates (e.g. aragonite, gypsum, halite) generally reacts as aquiclude - preventing direct drainage of the surrounding mountain freshwater aquifers. The high density differences between the hypersaline Dead Sea (1.24 g/cm3) and the approaching fresh water generates a flat dipping and stable Ghyben-Herzberg interface. However, a network of open fissures and cracks enables these freshwaters to regionally penetrate both, aquiclude and interface and to finally enter the Dead Sea on- and offshore. These offshore springs, also termed sublake groundwater discharge (SGD), are neither qualitatively nor quantitatively analysed yet. This is the reason why it is one of the most doubtful variables in existing balances of the lake's water budget and strongly requires improvement. To disclose pathways from the feeding mountain aquifers to the springs, intense hydrochemical and microbial investigations were carried out both, onshore and submarine. The waters have their origin in a variety of hard rock aquifers of Cretaceous age. After draining into the Dead Sea sediments, waters carry the easily soluble components (gypsum, halite) and the abundant organic matter, erodes and transports the hardly soluble minerals (clay and aragonite) and admix with briny pore water, respectively, which are all hosted in the sediment body. Diving campaigns allowed to map at least parts of the submarine spring cluster and to correlate their locations with neo-tectonic patterns. However, comprehensive mapping solely by divers is unfeasible due to the complexity and density of spring locations. The subsurface morphology is characterised by craters, walls, gullies and cones, occasionally nested and intensely anastomosed. To comprehensively understand reasons for specific discharge locations and their shapes, high-precision and high

  10. Ecology of Hypersaline Microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Kerkar, S.

    these are Solar Lake, Gavish Sabka and Ras Muhammad Pool near the Red Sea coast, Guerrero Negro on the Baja California coast, Lake Sivash near the Black Sea, Shark Bay in Western Australia and Ribandar salt pans in Goa, India. Hypersaline evaporation ponds have...H. Such environments are very dynamic experiencing significant seasonal variations in size, salinity and temperature. In additional to natural hypersaline lakes, numerous artificial solar lakes are man-made for the production of sea salt. Once NaCl precipitates...

  11. New types of submarine groundwater discharge from a saliferous clay formation - the case of the Dead Sea

    Science.gov (United States)

    Siebert, Christian; Broder, Merkel; Thomas, Pohl; Yossi, Yechieli; Eldat, Hazan; Danny, Ionescu; Ulf, Mallast

    2017-04-01

    Along the coastline of the hyper-saline and dramatically dropping Dead Sea, fresh to highly saline groundwaters discharge abundantly from dry falling lakebed. During its history, the level and hence salinity of the lake strongly fluctuated, resulting in the deposition of an alternating sequence of clayey and chemical sediments (mainly halite, carbonates and sulfates), intercalated by thick beds of halite and of coarse clastics around wadi outlets, respectively. Due to the asymmetrical shape of the lake's basin, these strata are deposited unequally along the eastern and western flank, why only groundwaters coming from the west have to pass thick layers of these sediments on their way into the lake. On the base of trace elements (REE), element ratios, stable and radioisotopes and microbiological findings, the observed onshore and offshore springs revealed, freshwaters discharge from both Cretaceous limestone aquifers and efficiently dissolve the easily soluble halite and flush the interstitial brines from the saliferous clay formation, immediately after entering the sedimentary strata. Abundant microbial activity result in the widespread production of sulfuric acid, accelerating erosion of carbonates and sulfates. These processes result in a fast and striking karstification of the strata, enabling groundwaters to transcendent the fresh/saltwater interface trough open pipes. As results, submarine groundwater discharge (SGD) occurs randomly and in addition to terrestrial, submarine sinkholes develop very quickly too. Due to the variable maturity of the flow paths, salinity and chemical composition of SGD shows an extremely wide range, from potable water to TDS of >250 g/l. Submarine emerging groundwaters with salinities even higher then that of the Dead Sea and distinctly different chemical and isotopic composition form outlets, which are not known elsewhere and represent a novel and unique type of SGD, only observed in the Dead Sea yet.

  12. Tetrapyrroles and associated compounds in Dead Sea asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Aizenshtat, Z. (Hebrew Univ. of Jerusalem, Israel); Dinur, D.; Nissenbaum, A.

    1979-01-01

    Metallo- and free porphyrins (1000 to 1500 ppM) isolated from asphalts occurring as huge blocks floating in the northern part of the Dead Sea, have been analyzed by visible-uv (v-uv) spectrophotometry and by mass spectrometry. The concentration of vanadyl porphyrins in the asphalts exceeds by far that of the Ni-porphyrins, despite the l:3 V/Ni ratio found in the total asphalt sample. The free porphyrins resemble those from the Uinta Basin (USA) gilsonite and contain a mixture of homologous Aetio- and deoxyphyllo-erythroaetioporphyrins (DPEP). The non-porphyrin fraction of the asphalt showed an identical aliphatic, hydrocarbon distribution with that of heavy crude oil from the same area. The more polar fraction associated with the porphyrins was compared with the polar fraction of the previously described ozokerite from the Dead Sea area. From high-resolution MS, IR, v-uv and NMR spectra, combined with hydrolysis and GLC analysis, it is suggested that even-numbered (C/sub 12/, C/sub 16/, C/sub 18/, C/sub 18/ /sub 1/, C/sub 22/) fatty acids are associated with the asphaltic porphyrins, probably in the triglyceride form.

  13. 75 FR 7536 - Culturally Significant Objects Imported for Exhibition Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2010-02-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``The Dead Sea Scrolls: Words That... hereby determine that the objects to be included in the exhibition ``The Dead Sea Scrolls: Words That...

  14. 77 FR 36329 - Culturally Significant Objects Imported for Exhibition Determinations: “Dead Sea Scrolls & The...

    Science.gov (United States)

    2012-06-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Dead Sea Scrolls & The Bible Ancient... April 15, 2003), I hereby determine that the objects to be included in the exhibition ``Dead Sea Scrolls...

  15. Safety evaluation of traces of nickel and chrome in cosmetics: The case of Dead Sea mud.

    Science.gov (United States)

    Ma'or, Ze'evi; Halicz, Ludwik; Portugal-Cohen, Meital; Russo, Matteo Zanotti; Robino, Federica; Vanhaecke, Tamara; Rogiers, Vera

    2015-12-01

    Metal impurities such as nickel and chrome are present in natural ingredients-containing cosmetic products. These traces are unavoidable due to the ubiquitous nature of these elements. Dead Sea mud is a popular natural ingredient of cosmetic products in which nickel and chrome residues are likely to occur. To analyze the potential systemic and local toxicity of Dead Sea mud taking into consideration Dead Sea muds' natural content of nickel and chrome. The following endpoints were evaluated: (Regulation No. 1223/20, 21/12/2009) systemic and (SCCS's Notes of Guidance) local toxicity of topical application of Dead Sea mud; health reports during the last five years of commercial marketing of Dead Sea mud. Following exposure to Dead Sea mud, MoS (margin of safety) calculations for nickel and chrome indicate no toxicological concern for systemic toxicity. Skin sensitization is also not to be expected by exposure of normal healthy skin to Dead Sea mud. Topical application, however, is not recommended for already nickel-or chrome-sensitized persons. As risk assessment of impurities present in cosmetics may be a difficult exercise, the case of Dead Sea mud is taken here as an example of a natural material that may contain traces of unavoidable metals. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Load structure seismites in the Dead Sea Area, Israel : Chronological benchmarking with C-14 dating

    NARCIS (Netherlands)

    Bowman, D; Bruins, HJ; van der Plicht, J; Boaretto, E.; Bruins, Hendrik J.; Carmi, I.

    2001-01-01

    The Dead Sea is a terminal lake located in the seismically active zone of the Syro-African Rift Valley. The water level of the Dead Sea has been receding dramatically during the last decades, resulting in significant entrenchment of wadis towards its shores. Exposed sections in fan deltas reveal

  17. Modeling radium distribution in coastal aquifers during sea level changes: The Dead Sea case

    Science.gov (United States)

    Kiro, Yael; Yechieli, Yoseph; Voss, Clifford I.; Starinsky, Abraham; Weinstein, Yishai

    2012-01-01

    We present a new approach to studying the behavior of radium isotopes in a coastal aquifer. In order to simulate radium isotope distributions in the dynamic flow field of the Dead Sea aquifer, a multi-species density dependent flow model (SUTRA-MS) was used. Field data show that the activity of 226Ra decreases from 140 to 60 dpm/L upon entering the aquifer from the Dead Sea, and then further decreases linearly due to mixing with Ra-poor fresh water. On the other hand, an increase is observed in the activity of the shorter-lived isotopes (up to 52 dpm/L 224Ra and 31 dpm/L 223Ra), which are relatively low in Dead Sea water (up to 2.5 dpm/L 224Ra and 0.5 dpm/L 223Ra). The activities of the short lived radium isotopes also decrease with decreasing salinity, which is due to the effect of salinity on the adsorption of radium. The relationship between 224Ra and salinity suggests that the adsorption partition coefficient (K) is linearly related to salinity. Simulations of the steady-state conditions, show that the distance where equilibrium activity is attained for each radium isotope is affected by the isotope half-life, K and the groundwater velocity, resulting in a longer distance for the long-lived radium isotopes. K affects the radium distribution in transient conditions, especially that of the long-lived radium isotopes. The transient conditions in the Dead Sea system, with a 1 m/yr lake level drop, together with the radium field data, constrains K to be relatively low (226Ra cannot be explained by adsorption, and it is better explained by removal via coprecipitation, probably with barite or celestine.

  18. Dead Sea mud packs for chronic low back pain.

    Science.gov (United States)

    Abu-Shakra, Mahmoud; Mayer, Amit; Friger, Michael; Harari, Marco

    2014-09-01

    Low back pain (LBP) is chronic disease without a curative therapy. Alternative and complementary therapies are widely used in the management of this condition. To evaluate the efficacy of home application of Dead Sea mud compresses to the back of patients with chronic LBP. Forty-six consecutive patients suffering from chronic LBP were recruited. All patients were followed at the Soroka University Rheumatic Diseases Unit. The patients were randomized into two groups: one group was treated with mineral-rich mud compresses, and the other with mineral-depleted compresses. Mud compresses were applied five times a week for 3 consecutive weeks. The primary outcome was the patient's assessment of the overall back pain severity. The score of the Ronald & Morris questionnaire served as a secondary outcome. Forty-four patients completed the therapy and the follow-up assessments: 32 were treated with real mud packs and 12 used the mineral-depleted packs. A significant decrease in intensity of pain, as described by the patients, was observed only in the treatment group. In this group, clinical improvement was clearly seen at completion of therapy and was sustained a month later. Significant improvement in the scores of the Roland & Morris questionnaire was observed in both groups. The data suggest that pain severity was reduced in patients treated with mineral-rich mud compresses compared with those treated with mineral-depleted compresses. Whether this modest effect is the result of a "true" mud effect or other causes can not be determined in this study.

  19. Rheology of Dead Sea shampoo containing the antidandruff climbazole.

    Science.gov (United States)

    Abu-Jdayil, B; Mohameed, H A

    2004-12-01

    In this study, the effect of the antidandruff climbazole on the rheology of hair shampoo containing Dead Sea (DS) salt was investigated. The presence of either DS salt or the climbazole led to increase in the shampoo viscosity. An optimum concentration was found where the viscosity of shampoo was maximum. In the absence of DS salt, the viscosity of hair shampoo increased with increasing the climbazole concentration to reach a maximum value at 1.0 wt%. Further addition of climbazole decreased the viscosity of shampoo. Adjusting the pH of the shampoo at 5.5 and 5.0 shifted the optimum climbazole concentration (corresponds to maximum viscosity) to 0.8 wt% and led to increase in the viscosity of shampoo. On the other hand, the addition of climbazole to the shampoo containing DS salt resulted in a decrease in shampoo viscosity. This decrease of shampoo viscosity became more pronounced with increasing the climbazole and/or DS salt concentrations. By controlling the pH of shampoo, an optimum formula of shampoo comprising both climbazole and DS salt and having maximum viscosity was obtained.

  20. The material variance of the Dead Sea Scrolls : on texts and artefacts : original research

    National Research Council Canada - National Science Library

    Tigchelaar, Eibert

    2016-01-01

    ...? Does materiality matter? This article deals with three different aspects of material variance attested amongst the Dead Sea Scrolls, Ancient Jewish religious text fragments, of which were found in the Judean Desert...

  1. The material variance of the Dead Sea Scrolls: On texts and artefacts

    National Research Council Canada - National Science Library

    Eibert Tigchelaar

    2016-01-01

    ...? Does materiality matter? This article deals with three different aspects of material variance attested amongst the Dead Sea Scrolls, Ancient Jewish religious text fragments, of which were found in the Judean Desert...

  2. Should the Dead Sea Be Sustainable?: Investigating Environmental Issues Using a Case Study

    Science.gov (United States)

    Saunders, Cheston Andrew

    2016-01-01

    Many students leave the environmental science classroom with misconceptions centered on the availability of natural resources such as water. This article presents a case study where students assume the roles of various stakeholders and articulate their position on whether or not to pipe water from the Red Sea to the Dead Sea. Additionally,…

  3. Monitoring of sinkholes and subsidence affecting the Jordanian coast of the Dead Sea through Synthetic Aperture Radar data and last generation Sentinel-1 data

    Science.gov (United States)

    Tessari, Giulia; Riccardi, Paolo; Lecci, Daniele; Pasquali, Paolo; Floris, Mario

    2017-04-01

    Since the mid-1980s the coast of the Dead Sea is affected by sinkholes occurring over and around the emerged mud and salt flats. Strong subsidence and landslides also affect some segments of the coast. Nowadays, several thousands of sinkholes attest that the degradation of the Dead Sea coast is worsening. Furthermore, soil deformations are interesting the main streets running along both the Israeli and Jordanian sides of the Dead Sea. These hazards are due to the dramatic dropping of the Dead Sea level, characterized by an increasing rate from about 60 cm/yr in the 1970s up to 1 m/yr in the 2000s, which provokes a lowering of the fresh-saline groundwater interface, replacing the hypersaline groundwater with fresh water and causing a consequent erosion of the subsurface salt layers. Subsidence, sinkholes, river erosion and landslides damage bridges, roads, dikes, houses, factories worsening this ongoing disaster. One of the most emblematic effects is the catastrophic collapse of a 12-km newly constructed dyke, located on the Lisan Peninsula (Jordan), occurred in 2000. Differential Interferometric Synthetic Aperture Radar (DInSAR) techniques and Advanced stacking DInSAR techniques (A-DInSAR) were applied to investigate sinkholes and subsidence affecting the Jordanian coast of the Dead Sea. The use of SAR data already proof to be efficient on the risk management of the area, allowing to identify a vulnerable portion of an Israeli highway, averting a possible collapse. Deformation analysis has been focused on the Ghor Al Haditha area and Lisan peninsula, located in the South-Eastern part of the lake coast. The availability of a huge database of SAR data, since the beginning of the 90s, allowed to observe the evolution of the displacements which are damaging this area. Furthermore, last generation Sentinel-1 data, acquired by the ESA mission, were processed to obtain information about the recent evolution of the subsidence and sinkholes affecting the study area, from

  4. Quality of life at the Dead Sea region: the lower the better? An observational study.

    Science.gov (United States)

    Avriel, Avital; Fuchs, Lior; Plakht, Ygal; Cicurel, Assi; Apfelbaum, Armando; Satran, Robert; Friger, Michael; Dartava, Dimitry; Sukenik, Shaul

    2011-05-27

    The Dead Sea region, the lowest in the world at 410 meters below sea level, is considered a potent climatotherapy center for the treatment of different chronic diseases. To assess the prevalence of chronic diseases and the quality of life of residents of the Dead Sea region compared with residents of the Ramat Negev region, which has a similar climate, but is situated 600 meters above sea level. An observational study based on a self-administered questionnaire. Data were collected from kibbutz (communal settlement) members in both regions. Residents of the Dead Sea were the study group and of Ramat Negev were the control group. We compared demographic characteristics, the prevalence of different chronic diseases and health-related quality of life (HRQOL) using the SF-36 questionnaire. There was a higher prevalence of skin nevi and non-inflammatory rheumatic diseases (NIRD) among Dead Sea residents, but they had significantly higher HRQOL mean scores in general health (68.7 ± 21 vs. 64.4 ± 22, p = 0.023) and vitality (64.7 ± 17.9 vs. 59.6 ± 17.3, p = 0.001), as well as significantly higher summary scores: physical component score (80.7 ± 18.2 vs. 78 ± 18.6, p = 0.042), and mental component score (79 ± 16.4 vs. 77.2 ± 15, p = 0.02). These results did not change after adjusting for social-demographic characteristics, health-related habits, and chronic diseases. No significant difference between the groups was found in the prevalence of most chronic diseases, except for higher rates of skin nevi and NIRD among Dead Sea residents. HRQOL was significantly higher among Dead Sea residents, both healthy or with chronic disease.

  5. New perspectives on interdisciplinary earth science at the Dead Sea: The DESERVE project

    Energy Technology Data Exchange (ETDEWEB)

    Kottmeier, Christoph, E-mail: Christoph.Kottmeier@kit.edu [Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, Eggenstein-Leopoldshafen (Germany); Agnon, Amotz [The Hebrew University of Jerusalem, Jerusalem (Israel); Al-Halbouni, Djamil [GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam (Germany); Alpert, Pinhas [Tel Aviv University, Tel Aviv-Yafo (Israel); Corsmeier, Ulrich [Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, Eggenstein-Leopoldshafen (Germany); Dahm, Torsten [GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam (Germany); Eshel, Adam [Tel Aviv University, Tel Aviv-Yafo (Israel); Geyer, Stefan [Helmholtz Centre for Environmental Research GmbH — UFZ, Theodor-Lieser-Strasse 4, 06120 Halle (Germany); Haas, Michael; Holohan, Eoghan [GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam (Germany); Kalthoff, Norbert [Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, Eggenstein-Leopoldshafen (Germany); Kishcha, Pavel [Tel Aviv University, Tel Aviv-Yafo (Israel); Krawczyk, Charlotte [Leibniz Institute for Applied Geophysics (LIAG), Stilleweg 2, 30655 Hannover (Germany); Lati, Joseph [Tel Aviv University, Tel Aviv-Yafo (Israel); Laronne, Jonathan B. [Ben Gurion University of the Negev, Be' er Sheva (Israel); Lott, Friederike [Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, Eggenstein-Leopoldshafen (Germany); Mallast, Ulf; Merz, Ralf [Helmholtz Centre for Environmental Research GmbH — UFZ, Theodor-Lieser-Strasse 4, 06120 Halle (Germany); Metzger, Jutta [Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, Eggenstein-Leopoldshafen (Germany); Mohsen, Ayman [An-Najah National University, Nablus, Palestine (Country Unknown); and others

    2016-02-15

    The Dead Sea region has faced substantial environmental challenges in recent decades, including water resource scarcity, ~ 1 m annual decreases in the water level, sinkhole development, ascending-brine freshwater pollution, and seismic disturbance risks. Natural processes are significantly affected by human interference as well as by climate change and tectonic developments over the long term. To get a deep understanding of processes and their interactions, innovative scientific approaches that integrate disciplinary research and education are required. The research project DESERVE (Helmholtz Virtual Institute Dead Sea Research Venue) addresses these challenges in an interdisciplinary approach that includes geophysics, hydrology, and meteorology. The project is implemented by a consortium of scientific institutions in neighboring countries of the Dead Sea (Israel, Jordan, Palestine Territories) and participating German Helmholtz Centres (KIT, GFZ, UFZ). A new monitoring network of meteorological, hydrological, and seismic/geodynamic stations has been established, and extensive field research and numerical simulations have been undertaken. For the first time, innovative measurement and modeling techniques have been applied to the extreme conditions of the Dead Sea and its surroundings. The preliminary results show the potential of these methods. First time ever performed eddy covariance measurements give insight into the governing factors of Dead Sea evaporation. High-resolution bathymetric investigations reveal a strong correlation between submarine springs and neo-tectonic patterns. Based on detailed studies of stratigraphy and borehole information, the extension of the subsurface drainage basin of the Dead Sea is now reliably estimated. Originality has been achieved in monitoring flash floods in an arid basin at its outlet and simultaneously in tributaries, supplemented by spatio-temporal rainfall data. Low-altitude, high resolution photogrammetry, allied to

  6. Simulation of the Aerosol-Atmosphere Interaction in the Dead Sea Area with COSMO-ART

    Science.gov (United States)

    Vogel, Bernhard; Bangert, Max; Kottmeier, Christoph; Rieger, Daniel; Schad, Tobias; Vogel, Heike

    2014-05-01

    The Dead Sea is a unique environment located in the Dead Sea Rift Valley. The fault system of the Dead Sea Rift Valley marks the political borders between Israel, Jordan, and Palestine. The Dead Sea region and the ambient Eastern Mediterranean coastal zone provide a natural laboratory for studying atmospheric processes ranging from the smallest scale of cloud processes to regional weather and climate. The virtual institute DESERVE is designed as a cross-disciplinary and cooperative international project of the Helmholtz Centers KIT, GFZ, and UFZ with well-established partners in Israel, Jordan and Palestine. One main focus of one of the work packages is the role of aerosols in modifying clouds and precipitation and in developing the Dead Sea haze layer as one of the most intriguing questions. The haze influences visibility, solar radiation, and evaporation and may even affect economy and health. We applied the online coupled model system COSMO-ART, which is able to treat the feedback processes between aerosol, radiation, and cloud formation, for a case study above the Dead Sea and adjacent regions. Natural aerosol like mineral dust and sea salt as well as anthropogenic primary and secondary aerosol is taken into account. Some of the observed features like the vertical double structure of the haze layer are already covered by the simulation. We found that absorbing aerosol like mineral dust causes a temperature increase in parts of the model domain. In other areas a decrease in temperature due to cirrus clouds modified by elevated dust layers is simulated.

  7. A Three-Dimensional Seismic Model of the Dead Sea Plate Boundary From Active Source Data

    Science.gov (United States)

    Flores, C. H.; ten Brink, U. S.

    2007-12-01

    The Dead Sea fault system is a north-south striking left-lateral shear zone separating the African and Arabian tectonic plates. The southern part of the plate boundary is located within the Dead Sea valley. The valley, much of it below sea level, is surrounded by highlands on both sides, and contains subsurface sedimentary basins, including the large (~150 km long) a deep (6-8 km) Dead Sea basin. A wide-angle seismic reflection and refraction experiment was carried out in the Dead Sea Region in October 2004 to study the deep structure of the plate boundary. The experiment consisted of two perpendicular profiles a 280-km long profile along the valley and the international border between Jordan, Israel and the Palestinian Territories, and a 250 km long profile from Gaza strip to eastern Jordan across the Dead Sea basin. Modeling of the West-East line shows a low velocity zone extending to a depth of 18 km below the basin, which includes >6 km of "syn-rift" sediments (ten Brink et al., GRL, 2006). The lower crust and Moho are not perturbed. The uplift surrounding the Dead Sea Transform also appears to be an upper crustal phenomenon. The shear deformation, associated with the transform plate boundary motion appears, on the other hand, to cut throughout the entire crust (Ibid.). Two-dimensional modeling of the South-North line is more complex due to the fact that sedimentary basins do not occupy the entire width of the valley hence some sources and some receivers are located within the basins whereas others are located outside. This heterogeneous near-surface structure explains why a simple 2-D velocity model does not fit the observed travel times from all shots. Therefore, we are using 3-D travel-time tomography to model the heterogeneous near-surface and deeper structure of the Dead Sea. Preliminary models indicate that some ray-paths from sources near the basin use the edges of the basin as a wave-guide and generate earlier than expected arrivals at receivers near

  8. Geology and hydrocarbon potential of the Dead Sea Rift Basins of Israel and Jordan

    Science.gov (United States)

    Coleman, James; Ten Brink, Uri

    2016-01-01

    Following its middle Miocene inception, numerous basins of varying lengths and depths developed along the Dead Sea fault zone, a large continental transform plate boundary. The modern day left-lateral fault zone has an accumulated left-lateral offset of 105 to 110 km (65 to 68 mi). The deepest basin along the fault zone, the Lake Lisan or Dead Sea basin, reaches depths of 7.5 to 8.5 km (24,500 ft to 28,000 ft), and shows evidence of hydrocarbons. The basins are compartmentalized by normal faulting associated with rapid basin subsidence and, where present, domal uplift accompanying synrift salt withdrawal.

  9. The effects of possible contamination on the radiocarbon dating of the Dead Sea Scrolls I : Castor oil

    NARCIS (Netherlands)

    Rasmussen, KL; van der Plicht, J; Cryer, FH; Doudna, G; Cross, FM; Strugnell, J; Rasmussen, Kaare L.; Cryer, Frederick H.; Cross, Frank M.

    2001-01-01

    Some fragments of the Dead Sea Scroll manuscripts were contaminated with castor oil in the late 1950s. We have conducted experiments in order to establish if the AAA pretreatment cleaning procedures conducted on Dead Sea Scroll manuscript samples in the last two dating series (Bonani et al. 1992;

  10. The evolution of the Dead Sea brine during the last 220 ky as revealed by porewater Cl-, Na+ and δ18O in ICDP deep core

    Science.gov (United States)

    Lazar, Boaz; Levy, Elan J.; Sivan, Orit; Yechieli, Joseph; Antler, Gilad; Gavrieli, Ittai; Stein, Mordechai

    2016-04-01

    The chemical composition of pore brines extracted from 456 m long core drilled by the ICDP during 2011 in the deep basin (water depth of 300 m) of the Dead Sea provides a history of the evolution of the Dead Sea brine during the last 220 ky. The vertical profiles of chloride (Cl-) sodium (Na+) and oxygen isotopes (δ18O) in the core show that during that period the bottom water mass (hypolimnion) of the lake was always hyper-saline and its salinity did not dropped below ~70 % of that of the modern Dead Sea. The lake underwent three major hyper-arid periods that lasted altogether about 30 ky and deposited ~150 m of halite and gypsum. These periods were the last two interglacials and the postglacial till present. During the last glacial and particularly during MIS2 (~31-17 ka BP) the salinity of the lake dropped substantially due to excess input of freshwater as indicated by the decrease in Cl- and Na+ of the hypolimnion. The δ18O at the same period increased to maximum of ~7‰ (3‰ higher than today). The variations in Na+ and Cl- during the "freshening" period suggest that halite dissolution, probably due to the rise of mount Sedom diapir, "buffered" the brine from further drop in salinity. The dilution of the brine was slow and lasted more than 10 ky probably due to continuous turbulent mixing of the hypolimnion with the less saline high δ18O epilimnetic brine that underwent "normal" evaporation. The low δ18O during high salinity -halite deposition- periods is attributed to "reversed" behavior of δ18O during evaporation of high salinity brine. Massive precipitation of halite during the last 10 ky decreased sharply the Na+/Cl- ratio of the Dead Sea from ~0.7 to its present value of ~0.2. A similar low value was reached during the last interglacial, at ~120 ky. Both periods mark the most mature evaporative state of the lake during the last 220 ky.

  11. Opening of Dead Sea Scrolls Archive Underlines Problems That Can Complicate Access to Research Materials.

    Science.gov (United States)

    Coughlin, Ellen K.

    1991-01-01

    The Huntington Library (California) decision to make generally accessible, for the first time, copies of photographs of the Dead Sea Scrolls, previously tightly controlled by a small group of editors, is hailed as breaking a scholarly monopoly over an important intellectual resource, reaffirming the mission of the research library and the…

  12. Provisional, Primordial and Preexistent Temples in the Dead Sea Scrolls and Related Texts

    DEFF Research Database (Denmark)

    Holst, Søren

    2015-01-01

    The Bible itself indicates that there is a prehistory to the Solomonic temple: It existed in a portable version during the wilderness years in the shape of the Tabernacle, and that in turn was built after a model shown to Moses on Mt. Sinai by God himself. It is no wonder that the Dead Sea Scrolls...

  13. Paradigm Agreement and Literature Obsolescence: A Comparative Study in the Literature of the Dead Sea Scrolls.

    Science.gov (United States)

    Heisey, Terry M.

    1988-01-01

    This study used bibliometric reference analysis to compare archaeological and critical papers from the Dead Sea Scrolls literature. Data were gathered on the age of reference, the dates of the scientific (archaeological) research front, and form of publication. The significance of these findings for literature obsolescence is discussed. (50…

  14. The text-critical and exegetical value of the Dead Sea Scrolls

    African Journals Online (AJOL)

    2016-07-29

    Jul 29, 2016 ... The less helpful fragments from the Biblical books Proverbs and Job are taken as examples. Finally, highly significant textual differences, such as a fragment from Genesis 1 and one from the complicated books of Jeremiah, will be evaluated. The text-critical and exegetical value of the Dead. Sea Scrolls.

  15. Why Transcripts of the Dead Sea Scrolls Had to Be Released.

    Science.gov (United States)

    Shanks, Hershel

    1991-01-01

    The editor of the "Biblical Archaeology Review" defends publication of an unauthorized copy of the Dead Sea Scrolls transcripts, which used the reconstructive work of others. The ethics of publishing reconstructed transcripts, the history of the documents since their discovery, and the rights and responsibilities of scholars are…

  16. The rift-like structure and asymmetry of the Dead Sea Fault

    NARCIS (Netherlands)

    Smit, J.H.W.; Brun, J.P.; Cloetingh, S.A.P.L.; Ben-Avraham, Z.

    2010-01-01

    Whereas the Dead Sea Fault is a major continental transform, active since ca. 13-18 Ma ago, it has a rift-like morphology along its southern part. It has been argued that this results from a transtensional component active since 5 Ma ago, due to a regional plate kinematics change. We present the

  17. Provenance studies on Dead Sea scrolls parchment by means of quantitative micro-XRF.

    Science.gov (United States)

    Wolff, Timo; Rabin, Ira; Mantouvalou, Ioanna; Kanngiesser, Birgit; Malzer, Wolfgang; Kindzorra, Emanuel; Hahn, Oliver

    2012-02-01

    In this study, we address the question of the provenance and origin of the Dead Sea Scrolls manuscripts. A characteristic low ratio of chlorine to bromine, corresponding to that of the Dead Sea water, may serve as an indicator for local production. For this aim we developed a non-destructive procedure to determine the Cl/Br ratio in the parchment of these manuscripts. Micro-X-ray fluorescence (μ-XRF) measurements of a large number of parchment and leather fragments from the Dead Sea Scrolls were analyzed with a routine we developed based on fundamental parameter quantification. This routine takes into account the absorption of the collagen matrix and the influence of the different sample thicknesses. To calculate the representative Cl/Br ratio for each fragment, we investigated the lateral homogeneity and determined the total mass deposition using the intensity of the inelastically scattered, characteristic tube radiation. The distribution of the Cl/Br ratios thus obtained from the μ-XRF measurements make it possible to distinguish fragments whose origin lies within the Dead Sea region from those produced in other locations.

  18. Stratigraphy, climate and downhole logging data - an example from the ICDP Dead Sea deep drilling project

    Science.gov (United States)

    Coianiz, Lisa; Ben-Avraham, Zvi; Lazar, Michael

    2017-04-01

    During the late Quaternary a series of lakes occupied the Dead Sea tectonic basin. The sediments that accumulated within these lakes preserved the environmental history (tectonic and climatic) of the basin and its vicinity. Most of the information on these lakes was deduced from exposures along the marginal terraces of the modern Dead Sea, e.g. the exposures of the last glacial Lake Lisan and Holocene Dead Sea. The International Continental Drilling Program (ICDP) project conducted in the Dead Sea during 2010-2011 recovered several cores that were drilled in the deep depocenter of the lake (water depth of 300 m) and at the margin (depth of 3 m offshore Ein Gedi spa). New high resolution logging data combined with a detailed lithological description and published age models for the deep 5017-1-A borehole were used to establish a sequence stratigraphic framework for the Lakes Amora, Samra, Lisan and Zeelim strata. This study presents a stratigraphic timescale for reconstructing the last ca 225 ka. It provides a context within which the timing of key sequence surfaces identified in the distal part of the basin can be mapped on a regional and stratigraphic time frame. In addition, it permitted the examination of depositional system tracts and related driving mechanisms controlling their formation. The sequence stratigraphic model developed for the Northern Dead Sea Basin is based on the identification of sequence bounding surfaces including: sequence boundary (SB), transgressive surface (TS) and maximum flooding surface (MFS). They enabled the division of depositional sequences into a Lowstand systems tracts (LST), Transgressive systems tracts (TST) and Highstand systems tracts (HST), which can be interpreted in terms of relative lake level changes. The analysis presented here show that system tract stacking patterns defined for the distal 5017-1-A borehole can be correlated to the proximal part of the basin, and widely support the claim that changes in relative lake

  19. The 1170 and 1202 CE Dead Sea Rift earthquakes and long-term magnitude distribution of the Dead Sea Fault zone

    Science.gov (United States)

    Hough, S.E.; Avni, R.

    2009-01-01

    In combination with the historical record, paleoseismic investigations have provided a record of large earthquakes in the Dead Sea Rift that extends back over 1500 years. Analysis of macroseismic effects can help refine magnitude estimates for large historical events. In this study we consider the detailed intensity distributions for two large events, in 1170 CE and 1202 CE, as determined from careful reinterpretation of available historical accounts, using the 1927 Jericho earthquake as a guide in their interpretation. In the absence of an intensity attenuation relationship for the Dead Sea region, we use the 1927 Jericho earthquake to develop a preliminary relationship based on a modification of the relationships developed in other regions. Using this relation, we estimate M7.6 for the 1202 earthquake and M6.6 for the 1170 earthquake. The uncertainties for both estimates are large and difficult to quantify with precision. The large uncertainties illustrate the critical need to develop a regional intensity attenuation relation. We further consider the distribution of magnitudes in the historic record and show that it is consistent with a b-value distribution with a b-value of 1. Considering the entire Dead Sea Rift zone, we show that the seismic moment release rate over the past 1500 years is sufficient, within the uncertainties of the data, to account for the plate tectonic strain rate along the plate boundary. The results reveal that an earthquake of M7.8 is expected within the zone on average every 1000 years. ?? 2011 Science From Israel/LPPLtd.

  20. Foehn-induced effects on local dust pollution, frontal clouds and solar radiation in the Dead Sea valley

    Science.gov (United States)

    Kishcha, Pavel; Starobinets, Boris; Savir, Amit; Alpert, Pinhas; Kaplan, Michael

    2017-03-01

    Despite the long history of investigation of foehn phenomena, there are few studies of the influence of foehn winds on air pollution and none in the Dead Sea valley. For the first time the foehn phenomenon and its effects on local dust pollution, frontal cloudiness and surface solar radiation were analyzed in the Dead Sea valley, as it occurred on 22 March 2013. This was carried out using both numerical simulations and observations. The foehn winds intensified local dust emissions, while the foehn-induced temperature inversion trapped dust particles beneath this inversion. These two factors caused extreme surface dust concentration in the western Dead Sea valley. The dust pollution was transported by west winds eastward, to the central Dead Sea valley, where the speed of these winds sharply decreased. The transported dust was captured by the ascending airflow contributing to the maximum aerosol optical depth (AOD) over the central Dead Sea valley. On the day under study, the maximum surface dust concentration did not coincide with the maximum AOD: this being one of the specific effects of the foehn phenomenon on dust pollution in the Dead Sea valley. Radar data showed a passage of frontal cloudiness through the area of the Dead Sea valley leading to a sharp drop in noon solar radiation. The descending airflow over the downwind side of the Judean Mountains led to the formation of a cloud-free band followed by only the partial recovery of solar radiation because of the extreme dust pollution caused by foehn winds.

  1. New perspectives on interdisciplinary earth science at the Dead Sea: The DESERVE project.

    Science.gov (United States)

    Kottmeier, Christoph; Agnon, Amotz; Al-Halbouni, Djamil; Alpert, Pinhas; Corsmeier, Ulrich; Dahm, Torsten; Eshel, Adam; Geyer, Stefan; Haas, Michael; Holohan, Eoghan; Kalthoff, Norbert; Kishcha, Pavel; Krawczyk, Charlotte; Lati, Joseph; Laronne, Jonathan B; Lott, Friederike; Mallast, Ulf; Merz, Ralf; Metzger, Jutta; Mohsen, Ayman; Morin, Efrat; Nied, Manuela; Rödiger, Tino; Salameh, Elias; Sawarieh, Ali; Shannak, Benbella; Siebert, Christian; Weber, Michael

    2016-02-15

    The Dead Sea region has faced substantial environmental challenges in recent decades, including water resource scarcity, ~1m annual decreases in the water level, sinkhole development, ascending-brine freshwater pollution, and seismic disturbance risks. Natural processes are significantly affected by human interference as well as by climate change and tectonic developments over the long term. To get a deep understanding of processes and their interactions, innovative scientific approaches that integrate disciplinary research and education are required. The research project DESERVE (Helmholtz Virtual Institute Dead Sea Research Venue) addresses these challenges in an interdisciplinary approach that includes geophysics, hydrology, and meteorology. The project is implemented by a consortium of scientific institutions in neighboring countries of the Dead Sea (Israel, Jordan, Palestine Territories) and participating German Helmholtz Centres (KIT, GFZ, UFZ). A new monitoring network of meteorological, hydrological, and seismic/geodynamic stations has been established, and extensive field research and numerical simulations have been undertaken. For the first time, innovative measurement and modeling techniques have been applied to the extreme conditions of the Dead Sea and its surroundings. The preliminary results show the potential of these methods. First time ever performed eddy covariance measurements give insight into the governing factors of Dead Sea evaporation. High-resolution bathymetric investigations reveal a strong correlation between submarine springs and neo-tectonic patterns. Based on detailed studies of stratigraphy and borehole information, the extension of the subsurface drainage basin of the Dead Sea is now reliably estimated. Originality has been achieved in monitoring flash floods in an arid basin at its outlet and simultaneously in tributaries, supplemented by spatio-temporal rainfall data. Low-altitude, high resolution photogrammetry, allied to

  2. Synoptic conditions of fine-particle transport to the last interglacial Red Sea-Dead Sea from Nd-Sr compositions of sediment cores

    Science.gov (United States)

    Palchan, Daniel; Stein, Mordechai; Goldstein, Steven L.; Almogi-Labin, Ahuva; Tirosh, Ofir; Erel, Yigal

    2018-01-01

    The sediments deposited at the depocenter of the Dead Sea comprise high-resolution archive of hydrological changes in the lake's watershed and record the desert dust transport to the region. This paper reconstructs the dust transport to the region during the termination of glacial Marine Isotope Stage 6 (MIS 6; ∼135-129 ka) and the last interglacial peak period (MIS5e, ∼129-116 ka). We use chemical and Nd and Sr isotope compositions of fine detritus material recovered from sediment core drilled at the deepest floor of the Dead Sea. The data is integrated with data achieved from cores drilled at the floor of the Red Sea, thus, forming a Red Sea-Dead Sea transect extending from the desert belt to the Mediterranean climate zone. The Dead Sea accumulated flood sediments derived from three regional surface cover types: settled desert dust, mountain loess-soils and loess-soils filling valleys in the Dead Sea watershed termed here "Valley Loess". The Valley Loess shows a distinct 87Sr/86Sr ratio of 0.7081 ± 1, inherited from dissolved detrital calcites that originate from dried waterbodies in the Sahara and are transported with the dust to the entire transect. Our hydro-climate and synoptic conditions reconstruction illustrates the following history: During glacial period MIS6, Mediterranean cyclones governed the transport of Saharan dust and rains to the Dead Sea watershed, driving the development of both mountain soils and Valley Loess. Then, at Heinrich event 11, dry western winds blew Saharan dust over the entire Red Sea - Dead Sea transect marking latitudinal expansion of the desert belt. Later, when global sea-level rose, the Dead Sea watershed went through extreme aridity, the lake retreated, depositing salt and accumulating fine detritus of the Valley Loess. During peak interglacial MIS 5e, enhanced flooding activity flushed the mountain soils and fine detritus from all around the Dead Sea and Red Sea, marking a significant "contraction" of the desert belt

  3. Optically stimulated luminescence of natural NaCl mineral from Dead Sea exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Roman L, J.; Cruz Z, E. [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Pina L, Y. I. [UNAM, Facultad de Ciencias, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Marcazzo, J., E-mail: jesus.roman@nucleares.unam.mx [Instituto de Fisica Arroyo Seco - UNICEN, Pinto 399, 7000 Tandil (Argentina)

    2016-10-15

    Luminescence properties such as radioluminescence, thermoluminescence and optically stimulated luminescence have been studied on natural sodium chloride (NaCl) for dosimetric purposes in retrospective dosimetry (Timar-Gabor et al., 2013; Druzhyna et al., 2016). In this work, the optically stimulated luminescence (Cw-OSL) emissions of natural salt minerals, collected from Dead Sea in summer of 2015, were studied. The Cw-OSL dose response of natural salt was analyzed in the range between 0.2 and 10 Gy gamma dose of {sup 60}Co. Samples exposed at 3 Gy exhibited good repeatability with a variation coefficient of 4.6%. The thermal stability of the Cw-OSL response was analyzed to different temperatures from 50 up to 250 degrees Celsius using a heating rate of 5 degrees Celsius. The results showed that the natural Dead Sea salt minerals could be applied as natural dosimeter of gamma radiation. (Author)

  4. The material variance of the Dead Sea Scrolls: On texts and artefacts

    Directory of Open Access Journals (Sweden)

    Eibert Tigchelaar

    2016-05-01

    Full Text Available What does a sacred text look like? Are religious books materially different from other books? Does materiality matter? This article deals with three different aspects of material variance attested amongst the Dead Sea Scrolls, Ancient Jewish religious text fragments, of which were found in the Judean Desert. I suggest that the substitution of the ancient Hebrew script by the everyday Aramaic script, also for Torah and other religious texts, was intentional and programmatic: it enabled the broader diffusion of scriptures in Hellenistic and Roman Judea. The preponderant use of parchment for religious texts rather than papyrus may be a marker of identity. The many small scrolls which contained only small parts of specific religious books (Genesis, Psalms may have been produced as religious artefacts which express identity in the period when Judaism developed into a religion of the book. Keywords: Dead Sea Scrolls; Judaism; Manuscripts

  5. Quantitative assessment of in-situ salt karstification using shear wave velocity, Dead Sea

    OpenAIRE

    M. Ezersky; Legchenko, Anatoli

    2014-01-01

    The Dead Sea (DS) coastal areas have been dramatically affected by sinkhole formation since around 1990. Such sinkholes along both Israeli and Jordanian shores are linked to karst cavities that form through slow salt dissolution. A quantitative estimate of such in-situ salt karstification would be an important indicator of sinkhole hazard. One of the indications of salt karstification is its increased hydraulic conductivity, caused by the development of dissolution cavities forming conducting...

  6. Multi-Spectral Digital Imaging of Dead Sea Scrolls and Other Ancient Documents

    Science.gov (United States)

    Bearman, Gregory; Zuckerman, Bruce; Zuckerman, Ken; Chiu, Joseph

    1993-01-01

    It is well known that the Dead Sea scrolls and similar soft media texts are often difficult to read due to the inability of the epigrapher to distinguish the black ink with which they were written from the aged, blacked parchment on which they were inscribed. While considerable success has been achieved in enhancing the readability of these texts through infrared photography, this technique-as conventionally applied today-has distinct limitations.

  7. The Material Variance of the Dead Sea Scrolls: On Texts and Artefacts

    OpenAIRE

    Eibert Tigchelaar

    2016-01-01

    What does a sacred text look like? Are religious books materially different from other books? Does materiality matter? This article deals with three different aspects of material variance attested amongst the Dead Sea Scrolls, Ancient Jewish religious text fragments, of which were found in the Judean Desert. I suggest that the substitution of the ancient Hebrew script by the everyday Aramaic script, also for Torah and other religious texts, was intentional and programmatic: it enabled the bro...

  8. 3D Imaging of Dead Sea Area Using Weighted Multipath Summation: A Case Study

    Directory of Open Access Journals (Sweden)

    Shemer Keydar

    2013-01-01

    Full Text Available The formation of sinkholes along the Dead Sea is caused by the rapid decline of the Dead Sea level, as a possible result of human extensive activity. According to one of the geological models, the sinkholes in several sites are clustered along a narrow coastal strip developing along lineaments representing faults in NNW direction. In order to understand the relationship between a developing sinkhole and its tectonic environment, a high-resolution (HR three-dimensional (3D seismic reflection survey was carried out at the western shoreline of the Dead Sea. A recently developed 3D imaging approach was applied to this 3D dataset. Imaging of subsurface is performed by a spatial summation of seismic waves along time surfaces using recently proposed multipath summation with proper weights. The multipath summation is performed by stacking the target waves along all possible time surfaces having a common apex at the given point. This approach does not require any explicit information on parameters since the involved multipath summation is performed for all possible parameters values within a wide specified range. The results from processed 3D time volume show subhorizontal coherent reflectors at approximate depth of 50–80 m which incline on closer location to the exposed sinkhole and suggest a possible linkage between revealed fault and the sinkholes.

  9. Effect of the Dead Sea climatotherapy for psoriasis on quality of life.

    Science.gov (United States)

    Kopel, Eran; Levi, Assi; Harari, Marco; Ruzicka, Thomas; Ingber, Arieh

    2013-02-01

    It is well known that quality of life is an integral part in the outcome evaluation process of psoriasis treatment. Very few studies, however, examined the effect of climatotherapy at the Dead Sea on quality of life of such chronically ill patients. To determine the effect of the Dead Sea climatotherapy on the quality of life of patients with psoriasis vulgaris and psoriatic arthritis. A total of 119 patients participated in an observational prospective study carried out at the Deutsches Medizinisches Zentrum clinic, a medical skin care center specializing in climatotherapy. The patients completed questionnaires (Skindex-29) to quantify their quality of life at different time points: the day of arrival, the day of departure, and 3 and 6 months after the end of treatment. Marked improvement in the quality of life scores was measured between the time of arrival to time of departure and to 3 months after the end of treatment. Dead Sea climatotherapy has a significant positive influence on the quality of life of patients with psoriasis vulgaris and psoriatic arthritis.

  10. The effects of possible contamination on the radiocarbon dating of the Dead Sea Scrolls I: Castor oil

    OpenAIRE

    Rasmussen, KL; van der Plicht, J; Cryer, FH; Doudna, G; Cross, FM; Strugnell, J; Rasmussen, Kaare L.; Cryer, Frederick H.; Cross, Frank M.

    2001-01-01

    Some fragments of the Dead Sea Scroll manuscripts were contaminated with castor oil in the late 1950s. We have conducted experiments in order to establish if the AAA pretreatment cleaning procedures conducted on Dead Sea Scroll manuscript samples in the last two dating series (Bonani et al. 1992; Jull et al. 1995) were effective in removing oil contamination. Our experiments show that not all oil contamination can be expected to have been removed by the acid-alkaline-acid (AAA) pretreatment, ...

  11. The Last Interglacial in the Levant: Perspective from the ICDP Dead Sea Deep Drill Core

    Science.gov (United States)

    Goldstein, S. L.; Torfstein, A.; Stein, M.; Kushnir, Y.; Enzel, Y.; Haug, G. H.

    2014-12-01

    Sediments recovered by the ICDP Dead Sea Deep Drilling Project provide a new perspective on the climate history of the Levant during the last interglacial period MIS5. They record the extreme impacts of an intense interglacial characterized by stronger insolation, warmer mean global temperatures, and higher sea-levels than the Holocene. Results show both extreme hyper-aridity during MIS5e, including an unprecedented drawdown of Dead Sea water levels, and the impacts of a strong precession-driven African monsoon responsible for a major sapropel event (S5) in the eastern Mediterranean. Hyper-arid conditions at the beginning of MIS5e prior to S5 (~132-128 ka) are evidenced by halite deposition, indicating declining Dead Sea lake levels. Surprisingly, the hyper-arid phase is interrupted during the MIS5e peak (~128-120 ka), coinciding with the S5 sapropel, which is characterized by a thick (23 m) section of silty detritus (without any halite) whose provenance indicates southern-sourced wetness in the watershed. Upon weakening of the S5 monsoon (~120-115 ka), the return of extreme aridity resulted in an unprecedented lake level drawdown, reflected by massive salt deposition, and followed by a sediment hiatus (~115-100 ka) indicating prolonged low lake level. The resumption of section follows classic Levant patterns with more wetness during cooler MIS5b and hyper-aridity during warmer MIS5a. The ICDP core provides the first evidence for a direct linkage between an intense precession-driven African monsoon and wetness at the high subtropical latitude (~30N) of the Dead Sea watershed. Combined with coeval deposition of Negev speleothems and travertines, and calcitification of Red Sea corals, the evidence indicates a wet climatic corridor that could facilitate homo sapiens migration out of Africa during the MIS5e peak. In addition, the MIS 5e hyper-arid intervals may provide an important cautionary analogue for the impact of future warming on regional water resources.

  12. Unveiling microbial life in new deep-sea hypersaline Lake Thetis. Part I: Prokaryotes and environmental settings.

    Science.gov (United States)

    La Cono, Violetta; Smedile, Francesco; Bortoluzzi, Giovanni; Arcadi, Erika; Maimone, Giovanna; Messina, Enzo; Borghini, Mireno; Oliveri, Elvira; Mazzola, Salvatore; L'Haridon, Stephan; Toffin, Laurent; Genovese, Lucrezia; Ferrer, Manuel; Giuliano, Laura; Golyshin, Peter N; Yakimov, Michail M

    2011-08-01

    In September 2008, an expedition of the RV Urania was devoted to exploration of the genomic richness of deep hypersaline anoxic lakes (DHALs) located in the Western part of the Mediterranean Ridge. Approximately 40 nautical miles SE from Urania Lake, the presence of anoxic hypersaline lake, which we named Thetis, was confirmed by swath bathymetry profiling and through immediate sampling casts. The brine surface of the Thetis Lake is located at a depth of 3258 m with a thickness of ≈ 157 m. Brine composition was found to be thalassohaline, saturated by NaCl with a total salinity of 348‰, which is one of highest value reported for DHALs. Similarly to other Mediterranean DHALs, seawater-brine interface of Thetis represents a steep pycno- and chemocline with gradients of salinity, electron donors and acceptors and posseses a remarkable stratification of prokaryotic communities, observed to be more metabolically active in the upper interface where redox gradient was sharper. [(14) C]-bicarbonate fixation analysis revealed that microbial communities are sustained by sulfur-oxidizing chemolithoautotrophic primary producers that thrive within upper interface. Besides microaerophilic autotrophy, heterotrophic sulfate reduction, methanogenesis and anaerobic methane oxidation are likely the predominant processes driving the ecosystem of Thetis Lake. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  13. [Resistance of microorganisms of coastal ecosystems of the Dead Sea to extremal factors].

    Science.gov (United States)

    Romanovskaia, V A; Avdeeva, L V; Gladka, G V; Pritula, I R; Kharkhota, M A; Tashirev, A B

    2013-01-01

    Such extreme factors as UV radiation, high temperature and salinity, and also the small amount of accessible water have an influence on microorganisms of coastal ecosystems of the Dead Sea. Resistance to these factors of the microorganisms isolated from ecosystems of this region (vertical steep gorge around the Dead Sea, clay-salt plain and black highly mineralized muds) is studied. Aerobic, chemoorganotrophic, thermotolerant, moderately halophilic bacteria which, according to their morphological and physiological properties, are similar to species Gracilibacillus halotolerans, Salimicrobium album and genus Caryophanon have been isolated from these ecosystems. All strains grew at 0-10% of NaCl in the medium (one strain--at 15% of NaCl), in the range of 30-50 degrees C. Resistance to UV radiation has been revealed in all the investigated bacteria Lethal doses of UV (LD90 and LD99.99) for spore-forming strains of genus Gracilibacillus were 100-170 and 1100-1500 J/m2, respectively; for strain Salimicrobium 6t1 (does not form spores)--70 and 400 J/m2; for the strain lt4 (genus Caryophanon), forming filamentous (or trychomes)--150 and 1400 J/m2. Some strains of genus Gracilibacillus had strong antagonistic effect on conditionally pathogenic test cultures Staphylococcus aureus 209p and Candida albicans UCM Y-690. It is conceivable that resistance of microorganisms of coastal ecosystems of the Dead Sea to extreme factors was generated under the influence of abiotic (physical and chemical) factors typical of this region.

  14. Self-accelerated development of salt karst during flash floods along the Dead Sea Coast, Israel

    Science.gov (United States)

    Avni, Yoav; Lensky, Nadav; Dente, Elad; Shviro, Maayan; Arav, Reuma; Gavrieli, Ittai; Yechieli, Yoseph; Abelson, Meir; Lutzky, Hallel; Filin, Sagi; Haviv, Itai; Baer, Gidon

    2016-01-01

    We document and analyze the rapid development of a real-time karst system within the subsurface salt layers of the Ze'elim Fan, Dead Sea, Israel by a multidisciplinary study that combines interferometric synthetic aperture radar and light detection and ranging measurements, sinkhole mapping, time-lapse camera monitoring, groundwater level measurements and chemical and isotopic analyses of surface runoff and groundwater. The >1 m/yr drop of Dead Sea water level and the subsequent change in the adjacent groundwater system since the 1960s resulted in flushing of the coastal aquifer by fresh groundwater, subsurface salt dissolution, gradual land subsidence and formation of sinkholes. Since 2010 this process accelerated dramatically as flash floods at the Ze'elim Fan were drained by newly formed sinkholes. During and immediately after these flood events the dissolution rates of the subsurface salt layer increased dramatically, the overlying ground surface subsided, a large number of sinkholes developed over short time periods (hours to days), and salt-saturated water resurged downstream. Groundwater flow velocities increased by more than 2 orders of magnitudes compared to previously measured velocities along the Dead Sea. The process is self-accelerating as salt dissolution enhances subsidence and sinkhole formation, which in turn increase the ponding areas of flood water and generate additional draining conduits to the subsurface. The rapid terrain response is predominantly due to the highly soluble salt. It is enhanced by the shallow depth of the salt layer, the low competence of the newly exposed unconsolidated overburden and the moderate topographic gradients of the Ze'elim Fan.

  15. Pull-apart basin formation and development in narrow transform zones with application to the Dead Sea Basin

    NARCIS (Netherlands)

    Smit, J.H.W.; Brun, J.P.; Cloetingh, S.A.P.L.; Ben-Avraham, Z.

    2008-01-01

    Contrary to other examples, like Death Valley, California, and the Sea of Marmara, Turkey, the Dead Sea-type pull-apart basins form within a narrow transform corridor between strike-slip faults that are less than 10 km apart, much smaller than the crustal thickness of 35 km. In this paper we

  16. Anammox bacterial populations in deep marine hypersaline gradient systems

    NARCIS (Netherlands)

    Borin, S.; Mapelli, F.; Rolli, E.; Song, B.; Tobias, C.; Schmid, M.C.; de Lange, G.J.; Reichart, G.-J.; Schouten, S.; Jetten, M.; Daffonchio, D.

    2013-01-01

    To extend the knowledge of anaerobic ammonium oxidation (anammox) habitats, bacterial communities were examined in two hypersaline sulphidic basins in Eastern Mediterranean Sea. The 2 m thick seawater-brine haloclines of the deep anoxic hypersaline basins Bannock and L'Atalante were sampled in

  17. Measurement-based modeling of bromine chemistry in the boundary layer: 1. Bromine chemistry at the Dead Sea

    Directory of Open Access Journals (Sweden)

    E. Tas

    2006-01-01

    Full Text Available The Dead Sea is an excellent natural laboratory for the investigation of Reactive Bromine Species (RBS chemistry, due to the high RBS levels observed in this area, combined with anthropogenic air pollutants up to several ppb. The present study investigated the basic chemical mechanism of RBS at the Dead Sea using a numerical one-dimensional chemical model. Simulations were based on data obtained from comprehensive measurements performed at sites along the Dead Sea. The simulations showed that the high BrO levels measured frequently at the Dead Sea could only partially be attributed to the highly concentrated Br− present in the Dead Sea water. Furthermore, the RBS activity at the Dead Sea cannot solely be explained by a pure gas phase mechanism. This paper presents a chemical mechanism which can account for the observed chemical activity at the Dead Sea, with the addition of only two heterogeneous processes: the "Bromine Explosion" mechanism and the heterogeneous decomposition of BrONO2. Ozone frequently dropped below a threshold value of ~1 to 2 ppbv at the Dead Sea evaporation ponds, and in such cases, O3 became a limiting factor for the production of BrOx (BrO+Br. The entrainment of O3 fluxes into the evaporation ponds was found to be essential for the continuation of RBS activity, and to be the main reason for the jagged diurnal pattern of BrO observed in the Dead Sea area, and for the positive correlation observed between BrO and O3 at low O3 concentrations. The present study has shown that the heterogeneous decomposition of BrONO2 has a great potential to affect the RBS activity in areas influenced by anthropogenic emissions, mainly due to the positive correlation between the rate of this process and the levels of NO2. Further investigation of the influence of the decomposition of BrONO2 may be especially important in understanding the RBS activity at mid-latitudes.

  18. Microbiological and parasitological investigation among food handlers in hotels in the Dead Sea area, Jordan.

    Science.gov (United States)

    Abdel-Dayem, Muna; Al Zou'bi, Renad; Hani, Rehan Bani; Amr, Zuhair Sami

    2014-10-01

    Intestinal parasitic and bacterial infections constitute a major health issue in developing countries. The present study investigates and assesses infection rates among food handlers with intestinal parasites and microbial agents in luxurious hotels in the Dead Sea area of Jordan. A total of 901 stool samples were collected from food handlers (35 females and 866 males) employed in four main hotels in the Dead Sea area. Fecal samples were examined microscopically for intestinal parasites. Standard culture and biochemical techniques were used for the isolation and identification of Salmonella and Shigella spp. in stool samples. Five species of protozoan (Blastocystis hominis, Giardia intestinalis, Entamoeba coli, Entamoeba histolytica, and Endolimax nana), one helminth (Hymenolepis nana), and one cylindrical worm (Enterobius vermicularis) were recovered with an overall infection rate of 3.7%. G. intestinalis was the most prevalent parasitic infection with infection rate of 2.44%. All samples were negative for both Salmonella and Shigella. Findings highlight the important role of food handlers in the transmission of intestinal parasites to high-class clients accommodated in luxury hotels, and stress the urgent need for regular health and parasitologic examination of food handlers. Copyright © 2013. Published by Elsevier B.V.

  19. InSAR-based modeling and analysis of sinkholes along the Dead Sea coastline

    Science.gov (United States)

    Atzori, Simone; Antonioli, Andrea; Salvi, Stefano; Baer, Gidon

    2015-10-01

    Sinkholes commonly form by subsurface dissolution cavities that collapse after the overlying layers become mechanically unsupported. Sinkholes along the Dead Sea shorelines are preceded by, associated with, and followed by gradual surface subsidence that accompanies the cavities' growth. We exploit satellite radar interferometry (interferometric synthetic aperture radar) to resolve temporal and spatial relationships between gradual subsidence and sinkhole collapse. The geometry of the deflating cavity roof is determined by elastic inverse modeling of the surface displacements. A Coulomb failure stress criterion is applied to calculate the stress field induced by the deflating cavity at the ground surface. We find that the induced stress field favors generation of sinkholes at the perimeters of the subsiding areas rather than at their centers, in agreement with field observations, providing important information for sinkhole hazard assessment. Further, our analysis suggests that short-term deformation in consolidated gravel layers at shallow depths could be approximated by simple elastic modeling.

  20. Consequences of the anthropogenic alterations along the Jordanian Dead Sea coast

    Science.gov (United States)

    Closson, Damien; Abou Karaki, Najib

    2014-05-01

    The Dead Sea is a terminal lake located over the Jordan - Dead Sea transform fault. At around 428 m bsl, it is the lowest emerged place on Earth. Since the 1960s, the over-exploitation of the water resources in the catchment area has lead to lower the level at an increasing pace. In 2014, it is upper than 1m/year. In the last 50 years, a 50 by 15 km slice of brine, around 33 m thick, has disappeared. With a salinity ten times greater than the average ocean water, the lake and its underground lateral extensions act as a high density layer over which the fresh groundwater is in hydrostatic equilibrium. The slope of the interface between saline and fresh waters is ten times shallower than normally expected near the ocean. According to a number of wells, in some places, the water table does not drop at the same speed than the Dead Sea. There, the head difference is constantly increasing. The fresh groundwater moves rapidly towards the lake to compensate for the imbalance. The most conspicuous consequence is the proliferation of thousands of sinkholes and wide shallow subsidence. In parallel, in the last two decades, industrial and touristic developments have taken place along the coast. Hence, such a dynamic environment provides a unique test bed to study Human-Earth interaction in the Anthropocene. As an example, numerous ground collapses are distributed along lineaments whose orientations fit with the main structural directions. This observation highlights the role of conduit played by underground discontinuities, such as faults and fractures. Very rapid underground water circulation explains the appearance of vegetation (Tamarisk) in unexpected places such as the northern tip of the Lisan peninsula and an "aborted" hectometer-scale landslide. The reactivation of a paleo-channel located below a 38 M salt evaporation pond of the Arab Potash Company, Lisan area, Jordan, provides an example for the implementation of an Early warning System. Time series analysis of high

  1. Seismic surface-wave prospecting methods for sinkhole hazard assessment along the Dead Sea shoreline

    Science.gov (United States)

    Ezersky, M.; Bodet, L.; Al-Zoubi, A.; Camerlynck, C.; Dhemaied, A.; Galibert, P.-Y.; Keydar, S.

    2012-04-01

    The Dead Sea's coastal areas have been dramatically hit by sinkholes occurrences since around 1990 and there is an obvious potential for further collapse beneath main highways, agricultural lands and other populated places. The sinkhole hazard in this area threatens human lives and compromise future economic developments. The understanding of such phenomenon is consequently of great importance in the development of protective solutions. Several geological and geophysical studies tend to show that evaporite karsts, caused by slow salt dissolution, are linked to the mechanism of sinkhole formation along both Israel and Jordan shorelines. The continuous drop of the Dead Sea level, at a rate of 1m/yr during the past decade, is generally proposed as the main triggering factor. The water table lowering induces the desaturation of shallow sediments overlying buried cavities in 10 to 30 meters thick salt layers, at depths from 25 to 50 meters. Both the timing and location of sinkholes suggest that: (1) the salt weakens as result of increasing fresh water circulation, thus enhancing the karstification process; (2) sinkholes appear to be related to the decompaction of the sediments above karstified zones. The location, depth, thickness and weakening of salt layers along the Dead Sea shorelines, as well as the thickness and mechanical properties of the upper sedimentary deposits, are thus considered as controlling factors of this ongoing process. Pressure-wave seismic methods are typically used to study sinkhole developments in this area. P-wave refraction and reflection methods are very useful to delineate the salt layers and to determine the thickness of overlying sediments. But the knowledge of shear-wave velocities (Vs) should add valuable insights on their mechanical properties, more particularly when the groundwater level plays an important role in the process. However, from a practical point of view, the measurement of Vs remains delicate because of well-known shear

  2. A novel protein toxin from the deadly box jellyfish (Sea Wasp, Habu-kurage) Chiropsalmus quadrigatus.

    Science.gov (United States)

    Nagai, Hiroshi; Takuwa-Kuroda, Kyoko; Nakao, Masahiro; Oshiro, Naomasa; Iwanaga, Setsuko; Nakajima, Terumi

    2002-01-01

    The deadly box jellyfish (Sea Wasp, Habu-kurage in Japanese) Chiropsalmus quadrigatus Haeckel (Cubozoa) is distributed widely in the tropical Pacific region. In Japan, three fatal cases due to stings from this species have been reported officially. We successfully isolated C. quadrigatus toxin-A (CqTX-A, 44 kDa), a major proteinaceous toxin, for the first time, from the nematocysts of C. quadrigatus. CqTX-A showed lethal toxicity to crayfish when administered via intraperitoneal injection (LD50 = 80 microg/kg) and hemolytic activity toward 0.8% sheep red blood cells (ED50 = 160 ng/ml). Furthermore, we sequenced the cDNA encoding CqTX-A. The deduced amino acid sequence of CqTX-A (462 amino acids) showed 25.2% and 21.6% sequence similarity to Carybdea rastoni toxins (CrTXs) and Carybdea alata toxin-A (CrTX-A), respectively, which are Cubozoan jellyfish toxins.

  3. Shallow lithological structure across the Dead Sea Transform derived from geophysical experiments

    Science.gov (United States)

    Stankiewicz, J.; Munoz, G.; Ritter, O.; Bedrosian, P.A.; Ryberg, T.; Weckmann, U.; Weber, M.

    2011-01-01

    In the framework of the DEad SEa Rift Transect (DESERT) project a 150 km magnetotelluric profile consisting of 154 sites was carried out across the Dead Sea Transform. The resistivity model presented shows conductive structures in the western section of the study area terminating abruptly at the Arava Fault. For a more detailed analysis we performed a joint interpretation of the resistivity model with a P wave velocity model from a partially coincident seismic experiment. The technique used is a statistical correlation of resistivity and velocity values in parameter space. Regions of high probability of a coexisting pair of values for the two parameters are mapped back into the spatial domain, illustrating the geographical location of lithological classes. In this study, four regions of enhanced probability have been identified, and are remapped as four lithological classes. This technique confirms the Arava Fault marks the boundary of a highly conductive lithological class down to a depth of ???3 km. That the fault acts as an impermeable barrier to fluid flow is unusual for large fault zone, which often exhibit a fault zone characterized by high conductivity and low seismic velocity. At greater depths it is possible to resolve the Precambrian basement into two classes characterized by vastly different resistivity values but similar seismic velocities. The boundary between these classes is approximately coincident with the Al Quweira Fault, with higher resistivities observed east of the fault. This is interpreted as evidence for the original deformation along the DST originally taking place at the Al Quweira Fault, before being shifted to the Arava Fault. 

  4. Slip deficit and location of seismic gaps along the Dead Sea Fault

    Science.gov (United States)

    Meghraoui, Mustapha; Toussaint, Renaud; Ferry, Matthieu; Nguema-Edzang, Parfait

    2015-04-01

    The Dead Sea Fault (DSF), a ~ 1000-km-long North-South trending transform fault presents structural discontinuities and includes segments that experienced large earthquakes (Mw>7) in historical times. The Wadi Araba and Jordan Valley, the Lebanese restraining bend, the Missyaf and Ghab fault segments in Syria and the Ziyaret Fault segment in Turkey display geometrical complexities made of step overs, restraining and releasing bends that may constitute major obstacles to earthquake rupture propagation. Using active tectonics, GPS measurements and paleoseismology we investigate the kinematics and long-term/short-term slip rates along the Dead Sea fault. Tectonic geomorphology with paleoseismic trenching and archeoseismic investigations indicate repeated faulting events and left-lateral slip rate ranging from 4 mm/yr in the southern fault section to 6 mm/yr in the northern fault section. Except for the northernmost DSF section, these long-term estimates of fault slip rate are consistent with GPS measurements that show 4 to 5 mm/yr deformation rate across the plate boundary. Indeed, recent GPS results showing 3 +-0.5 mm/yr velocity rate of the northern DSF appear to be in contradiction with the ~6 mm/yr paleoseismic slip rate. The kinematic modeling that combines GPS and seismotectonic results implies a complex geodynamic pattern with the DSF transforms the Cyprus arc subduction zone into transpressive tectonics on the East Anatolian fault. The timing of past earthquake ruptures shows the occurrence of seismic sequences and a southward migration of large earthquakes, with the existence of major seismic gaps along strike. In this contribution, we present the calculated seismic slip deficit along the fault segments and discuss the identification of seismic gaps and the implication for the seismic hazard assessment.

  5. Geophysical analysis of the recent sinkhole trend at Ghor-Haditha (Dead Sea, Jordan)

    Science.gov (United States)

    Camerlynck, Christian; Bodet, Ludovic; Galibert, Pierre-Yves; Boucher, Marie; Al-Zoubi, Abdallah

    2013-04-01

    For essentially the last 30 year the water level of the Dead Sea has highly dropped. One of the major associated facts is sinkhole occurrences along the shoreline both in Jordan and Israel. As the principal invoked mechanism, many studies have concluded that sinkhole formation results from the dissolution of a previously immersed salt layer, progressively in contact with fresh to brackish water. In Jordan, the triggering of this phenomenon could also be the result of particular tectonic settings, associated with the Jordan-Dead Sea transform fault system. At Ghor Haditha (south-est Jordan), the consequences have been dramatic for farmers with the shrinking of temporary available lands and industry with the closing of at least one factory. The shallow material in this area is heterogeneous and composed of intercalated sand and clay layers of alluvial-colluvial origin, over a salty substratum, whose precise depth and thickness are yet partially hypothesized. Between 2005 and 2008, a multi-method high-resolution geophysical survey was performed, approximately over a 1 km2 area at Ghor Haditha, associating mainly electromagnetic soundings, magnetic resonance soundings (MRS), and seismic profiling, ground-penetrating radar and electrical resistivity tomography. At the same time, this specific area was the location of a dramatic evolution of sinkhole occurences, regularly followed by geodetic measurements. Over the 3 years period, about 120 TEM (Transient ElectroMagnetic) soundings allow to map precisely the depth of the conductive layers below the resistive overburden. Two conductive layer are then revealed, the latter showing the lowest resistivity below 1 Ohm.m corresponding to the saline substratum. Several MRS (3 in 2005, repeated in 2007 and 12 additional soundings) show an east-west hydraulic gradient towards the Dead. However, the main sinkhole trend coincides with both: - a clear low transmissivity axis determined from MRS measurements; - the western side of a

  6. Reading the human body : Physiognomics and Astrology in the Dead Sea Scrolls and Hellenistic-Early Roman Period Judaism

    NARCIS (Netherlands)

    Popovic, Mladen

    2006-01-01

    This study deals with two manuscripts from the Dead Sea Scrolls whose contents are physiognomic and physiognomic-astrological. These manuscripts contain material that was unknown to have existed in this form in Hellenistic-Early Roman period Judaism (ca. third century CE-first century ?CE) before

  7. Improved Dead Sea sinkhole site characterization at Ghor Al Haditha, Jordan, based on repeated shear wave reflection seismic profiling

    Science.gov (United States)

    Polom, Ulrich; Alrshdan, Hussam; Al-Halbouni, Djamil; Sawarieh, Ali; Dahm, Torsten; Krawczyk, CharLotte M.

    2016-04-01

    In October 2014 a high-resolution shallow shear wave reflection seismic survey was carried out at the Dead Sea sinkhole site Ghor Al Haditha, Jordan. It extended a survey undertaken in 2013, also in order to gather time-lapse profiles. In the framework of the DEad SEa Research Venue (DESERVE), a virtual institute of the Helmholtz Association and international partners, this investigation is part of a cross-disciplinary and cooperative international project of the Helmholtz Centers KIT, GFZ, and UFZ. At the investigation site, characterized by alluvial fan deposits, ongoing subsidence and sinkhole processes in the subsurface create massive reshaping of farming areas, including the destruction of housings, industrial sites, and infrastructure. The sinkhole hazard at the Dead Sea is significant, since similar processes are observed at several coastal segments of the Dead Sea. The new survey (in total 2.1 profile km) was targeted to improve the knowledge about the subsurface structures and to confine the results of the initial survey (1.8 km profile km), with respect to the presence or non-presence of a massive salt layer proposed at nearly 40 m depth. This salt layer is the central part of a widely established process hypothesis to generate shallow cavities by salt subrosion, which subsequently collapse to sinkholes at the surface. Results of the initial survey carried out in 2013 highlighted a new process hypothesis of subsurface mass transport by Dead Sea mud mobilization enclosed in the alluvial fan, so that an extended survey was undertaken in 2014. This, indeed, confirmed that there are no reflection seismic signal responses that would be expected to occur in the presence of a massive salt layer. Since evaluation of both hypothesis by new drilling could not be carried out due to safety reasons and permissions, it remained unclear which hypothesis is valid for the investigation site. However, we combined the 2013 and 2014 reflection seismic profiles and the

  8. Overview of the geophysical studies in the Dead Sea coastal area related to evaporite karst and recent sinkhole development

    Directory of Open Access Journals (Sweden)

    Mikhail G. Ezersky

    2017-05-01

    Full Text Available Since the early 80s, a progressively increasing number of sinkholes appeared along the Dead Sea coastal line. It has been found that their appearance is strongly correlating with the lowering of the Dead Sea level taking place with the rate of approximately 1 m/yr. Location of areas affected by sinkhole development corresponds to location of the salt formation deposited during the latest Pleistocene, when the Lake Lisan receded to later become the Dead Sea. Water flowing to the Dead Sea from adjacent and underlying aquifers dissolves salt and creates caverns that cause ground subsidence and consequent formation of sinkholes. Before subsidence, these caverns are not visible on the surface but can be investigated with surface geophysical methods. For that, we applied Surface Nuclear Magnetic Resonance (SNMR, Transient Electromagnetic (TEM Seismic refraction and reflection, Multichannel Analysis of Surface waves (MASW, microgravity and magnetic surveys and their combinations. Our geophysical results allowed us to locate the salt formation and to detect caverns in salt thus contributing to better understanding sinkhole development mechanisms. Comparison of sinkhole appearance along the western DS shore derived from the recent database (2017 shows that predictions made on the base of geophysical data (2005-2008 are now confirmed thus demonstrating efficiency of our study. In this paper, we briefly present a summary of up to date knowledge of the geology and hydrogeology of Dead Sea basin, of the physical properties of the salt rock and the most popular models explaining mechanisms of sinkhole development. We also share our experience gained during geophysical studies carried out in the framework of national and international research projects in this area for the last 20 years.

  9. Living and dead benthic foraminiferal assemblages from bathyal environment in the Pontine Archipelago (Tyrrhenian Sea, Italy)

    Science.gov (United States)

    Di Bella, Letizia; Frezza, Virgilio; Ingrassia, Michela; Latino Chiocci, Francesco; Martorelli, Eleonora

    2016-04-01

    The western Pontine Archipelago (Tyrrhenian Sea, Italy), located about 30 km away from the Italian Peninsula, is composed of three volcanic islands (Ponza, Palmarola and Zannone). Sedimentological and micropaleontological characterization of the infralittoral and circalittoral zones in the Pontine Archipelago was already been studied, whereas it is lacking for deeper environments. The present study shows the preliminary micropaleontological results carried out on samples collected in the bathyal zone (at 500 mwd) in the Ventotene basin. Sediment samples, high resolution multibeam bathymetry, biological and video data were acquired in order to characterise both the morphological and biological features of study area, during the research cruise "BOLLE 2014" carried out on June 2014 aboard to the R/V Urania. Sediment samples were collected with a multi-corer, that allowed sampling of the upper decimetre of the sediments column. Successively, each core was sliced horizontally every 1 cm from the top to the bottom. For micropaleontological analyses, all samples were stained with Rose Bengal to distinguish living and dead assemblages. For each interval of the core all living specimens and 200 dead benthic foraminifera were classified and counted. Diversity index (α-Fisher, Shannon indices) and Faunal Density (specimens/gr) were calculated to define the structure of the assemblage. A variable number of living benthic foraminifera (Rose Bengal-stained) were found in all core-intervals (7-155 tests), with the Faunal Density ranging from 3 to 82 specimens/gr. A total of 77 species are recognised from living benthic foraminiferal assemblages, with a range of 4-31 species found in each core-interval. The α-Fisher index ranges between 3.88 and 43.45, whereas Shannon index shows a more limited variability (1.28-2.92). Among the living foraminifera, calcareous imperforate tests are very abundant, with percentages ranging between 33.3 and 100%; perforate species are subordinate

  10. Clustering and interpretation of local earthquake tomography models in the southern Dead Sea basin

    Science.gov (United States)

    Bauer, Klaus; Braeuer, Benjamin

    2016-04-01

    The Dead Sea transform (DST) marks the boundary between the Arabian and the African plates. Ongoing left-lateral relative plate motion and strike-slip deformation started in the Early Miocene (20 MA) and produced a total shift of 107 km until presence. The Dead Sea basin (DSB) located in the central part of the DST is one of the largest pull-apart basins in the world. It was formed from step-over of different fault strands at a major segment boundary of the transform fault system. The basin development was accompanied by deposition of clastics and evaporites and subsequent salt diapirism. Ongoing deformation within the basin and activity of the boundary faults are indicated by increased seismicity. The internal architecture of the DSB and the crustal structure around the DST were subject of several large scientific projects carried out since 2000. Here we report on a local earthquake tomography study from the southern DSB. In 2006-2008, a dense seismic network consisting of 65 stations was operated for 18 months in the southern part of the DSB and surrounding regions. Altogether 530 well-constrained seismic events with 13,970 P- and 12,760 S-wave arrival times were used for a travel time inversion for Vp, Vp/Vs velocity structure and seismicity distribution. The work flow included 1D inversion, 2.5D and 3D tomography, and resolution analysis. We demonstrate a possible strategy how several tomographic models such as Vp, Vs and Vp/Vs can be integrated for a combined lithological interpretation. We analyzed the tomographic models derived by 2.5D inversion using neural network clustering techniques. The method allows us to identify major lithologies by their petrophysical signatures. Remapping the clusters into the subsurface reveals the distribution of basin sediments, prebasin sedimentary rocks, and crystalline basement. The DSB shows an asymmetric structure with thickness variation from 5 km in the west to 13 km in the east. Most importantly, a well-defined body

  11. Impacts of abrupt climate changes in the Levant from Last Glacial Dead Sea levels

    Science.gov (United States)

    Torfstein, Adi; Goldstein, Steven L.; Stein, Mordechai; Enzel, Yehouda

    2013-06-01

    A new, detailed lake level curve for Lake Lisan (the Last Glacial Dead Sea) reveals a high frequency of abrupt fluctuations during Marine Isotope Stage 3 (MIS3) compared to the relatively high stand characterizing MIS2, and the significantly lower Holocene lake. The lake level fluctuations reflect the hydrological conditions in the large watershed of the lake, which in turn reflects the hydro-climatic conditions in the central Levant region. The new curve shows that the fluctuations coincide on millennial timescales with temperature variations recorded in Greenland. Four patterns of correlation are observed through the last ice age: (1) maximum lake elevations were reached during MIS2, the coldest interval; (2) abrupt lake level drops to the lowest elevations coincided with the occurrence of Heinrich (H) events; (3) the lake returned to higher-stand conditions along with warming in Greenland that followed H-events; (4) significant lake level fluctuations coincided with virtually every Greenland stadial-interstadial cycle. Over glacial-interglacial time-scales, Northern Hemisphere glacial cooling induces extreme wetness in the Levant, with high lake levels reaching ˜160 m below mean sea level (mbmsl), approximately 240 m above typical Holocene levels of ˜400 mbmsl. These orbital time-scale shifts are driven by expansions of the European ice sheet, which deflect westerly storm tracks southward to the Eastern Mediterranean, resulting in increased sea-air temperature gradients that invoke increased cyclogenesis, and enhanced moisture delivery to the Levant. The millennial-scale lake level drops associated with Greenland stadials are most extreme during Heinrich stadials and reflect abrupt cooling of the Eastern Mediterranean atmosphere and sea-surface, which weaken the cyclogenic rain engine and cause extreme Levant droughts. During the recovery from the effect of Heinrich stadials, the regional climate configuration resumed typical glacial conditions, with enhanced

  12. Salt diapirs in the Dead Sea basin and their relationship to Quaternary extensional tectonics

    Science.gov (United States)

    Al-Zoubi, A.; ten Brink, U.S.

    2001-01-01

    Regional extension of a brittle overburden and underlying salt causes differential loading that is thought to initiate the rise of reactive diapirs below and through regions of thin overburden. We present a modern example of a large salt diapir in the Dead Sea pull-apart basin, the Lisan diapir, which we believe was formed during the Quaternary due to basin transtension and subsidence. Using newly released seismic data that are correlated to several deep wells, we determine the size of the diapir to be 13 x 10 km. its maximum depth 7.2 km. and its roof 125 m below the surface. From seismic stratigraphy, we infer that the diapir started rising during the early to middle Pleistocene as this section of the basin underwater rapid subsidence and significant extension of the overburden. During the middle to late Pleistocene, the diapir pierced through the extensionally thinned overburden, as indicated by rim synclines, which attest to rapid salt withdrawal from the surrounding regions. Slight positive topography above the diapir and shallow folded horizons indicate that it is still rising intermittently. The smaller Sedom diapir, exposed along the western bounding fault of the basin is presently rising and forms a 200 m-high ridge. Its initiation is explained by localized E-W extension due monoclinal draping over the edge of a rapidly subsiding basin during the early to middle Pleistocene, and its continued rise by lateral squeezing due to continued rotation of the Amazyahu diagonal fault. 

  13. Solid-state and unilateral NMR study of deterioration of a Dead Sea Scroll fragment.

    Science.gov (United States)

    Masic, A; Chierotti, M R; Gobetto, R; Martra, G; Rabin, I; Coluccia, S

    2012-02-01

    Unilateral and solid-state nuclear magnetic resonance (NMR) analyses were performed on a parchment fragment of the Dead Sea Scroll (DSS). The analyzed sample belongs to the collection of non-inscribed and nontreated fragments of known archaeological provenance from the John Rylands University Library in Manchester. Therefore, it can be considered as original DSS material free from any contamination related to the post-discovery period. Considering the paramount significance of the DSS, noninvasive approaches and portable in situ nondestructive methods are of fundamental importance for the determination of composition, structure, and chemical-physical properties of the materials under study. NMR studies reveal low amounts of water content associated with very short proton relaxation times, T(1), indicating a high level of deterioration of collagen molecules within scroll fragments. In addition, (13)C cross-polarization magic-angle-spinning (CPMAS) NMR spectroscopy shows characteristic peaks of lipids whose presence we attribute to the production technology that did not involve liming. Extraction with chloroform led to the reduction of both lipid and protein signals in the (13)C CPMAS spectrum indicating probable involvement of lipids in parchment degradation processes. NMR absorption and relaxation measurements provide nondestructive, discriminative, and sensitive tools for studying the deterioration effects on the organization and properties of water and collagen within ancient manuscripts.

  14. Quantifying degradation of collagen in ancient manuscripts: the case of the Dead Sea Temple Scroll.

    Science.gov (United States)

    Schütz, R; Bertinetti, L; Rabin, I; Fratzl, P; Masic, A

    2013-10-07

    Since their discovery in the late 1940s, the Dead Sea Scrolls, some 900 ancient Jewish texts, have never stopped attracting the attention of scholars and the broad public alike, because they were created towards the end of the Second Temple period and the "time of Christ". Most of the work on them has been dedicated to the information contained in the scrolls' text, leaving physical aspects of the writing materials unexamined. They are, however, crucial for both historical insight and preservation of the scrolls. Although scientific analysis requires handling, it is essential to establish the state of degradation of these valued documents. Polarized Raman Spectroscopy (PRS) is a powerful tool for obtaining information on both the composition and the level of disorder of molecular units. In this study, we developed a non-invasive and non-destructive methodology that allows a quantification of the disorder (that can be related to the degradation) of protein molecular units in collagen fibers. Not restricted to collagen, this method can be applied also to other protein-based fibrous materials such as ancient silk, wool or hair. We used PRS to quantify the degradation of the collagen fibers in a number of fragments of the Temple Scroll (11Q19a). We found that collagen fibers degrade heterogeneously, with the ones on the surface more degraded than those in the core.

  15. Effect of formulation variables on the physical properties and stability of Dead Sea mud masks.

    Science.gov (United States)

    Shahin, Sawsan; Hamed, Saja; Alkhatib, Hatim S

    2015-01-01

    The physical stability of Dead Sea mud mask formulations under different conditions and their rheological properties were evaluated as a function of the type and level of thickeners, level of the humectant, incorporation of ethanol, and mode of mud treatment. Formulations were evaluated in terms of visual appearance, pH, moisture content, spreadability, extrudability, separation, rate of drying at 32 degrees C, and rheological properties. Prepared mud formulations and over-the-shelf products showed viscoplastic shear thinning behavior; satisfactory rheological behavior was observed with formulations containing a total concentration of thickeners less than 10% (w/w). Casson and Herschel-Bulkley models were found the most suitable to describe the rheological data of the prepared formulations. Thickener incorporation decreased phase separation and improved formulation stability. Bentonite incorporation in the mud prevented color changes during stability studies while glycerin improved spreadability. Addition of 5% (w/w) ethanol improved mud extrudability, slightly increased percent separation, accelerated drying at 32 degrees C, and decreased viscosity and yield stress values. Different mud treatment techniques did not cause a clear behavioral change in the final mud preparation. B10G and K5B5G were labeled as "best formulas" based on having satisfactory physical and aesthetic criteria investigated in this study, while other formulations failed in one or more of the tests we have performed.

  16. Selenihalanaerobacter shriftii gen. nov., sp. nov., a halophilic anaerobe from Dead Sea sediments that respires selenate

    Science.gov (United States)

    Switzer, Blum J.; Stolz, J.F.; Oren, A.; Oremland, R.S.

    2001-01-01

    We isolated an obligately anaerobic halophilic bacterium from the Dead Sea that grew by respiration of selenate. The isolate, designated strain DSSe-1, was a gram-negative, non-motile rod. It oxidized glycerol or glucose to acetate+CO2 with concomitant reduction of selenate to selenite plus elemental selenium. Other electron acceptors that supported anaerobic growth on glycerol were nitrate and trimethylamine-N-oxide; nitrite, arsenate, fumarate, dimethylsulfoxide, thiosulfate, elemental sulfur, sulfite or sulfate could not serve as electron acceptors. Growth on glycerol in the presence of nitrate occurred over a salinity range from 100 to 240 g/l, with an optimum at 210 g/l. Analysis of the 16S rRNA gene sequence suggests that strain DSSe-1 belongs to the order Halanaerobiales, an order of halophilic anaerobes with a fermentative or homoacetogenic metabolism, in which anaerobic respiratory metabolism has never been documented. The highest 16S rRNA sequence similarity (90%) was found with Acetohalobium arabaticum (X89077). On the basis of physiological properties as well as the relatively low homology of 16S rRNA from strain DSSe-1 with known genera, classification in a new genus within the order Halanaerobiales, family Halobacteroidaceae is warranted. We propose the name Selenihalanaerobacter shriftii. Type strain is strain DSSe-1 (ATCC accession number BAA-73).

  17. Evaluation and mapping of Dead Sea coastal aquifers salinity using Transient Electromagnetic (TEM) resistivity measurements

    Science.gov (United States)

    Ezersky, Michael G.; Frumkin, Amos

    2017-01-01

    Evaporite karst has intensively developed recently along the Dead Sea (DS) coastal area in Israel and Jordan. It takes place in very saline groundwater dissolving buried salt layers, causing collapse of the surface. In this paper, groundwater salinity throughout the DS coastal area is investigated using the Transient Electromagnetic (TEM) method. Twenty-eight TEM soundings along the DS coastal area were carried out close to observation boreholes to calibrate resistivity-salinity relationships. Groundwater electrical conductivity was measured in these boreholes, and its salinity was analyzed at the laboratory by the Geological Survey of Israel (GSI). Quantitative relationships between bulk resistivity (ρx), water resistivity (ρw) and chloride concentration (Ccl) were derived in the resistivity range less than 1.0 Ω·m that enabled to evaluate the salinity of the aquifer in in situ conditions. Average values of the effective porosity of sandy sediments, φe = 0.32, and of silty ones, φe = 0.44, were used to generate the corresponding Archie equations. The study has shown that a DS aquifer with bulk resistivity in the range of 0.55-1.0 Ω·m contains in pores brine with 50-110 gchloride/l of (22-50% of that in saturated conditions, respectively), i.e. it keeps the potential to dissolve up to 114-174 g/l of salt.

  18. Aged keratinocyte phenotyping: morphology, biochemical markers and effects of Dead Sea minerals.

    Science.gov (United States)

    Soroka, Yoram; Ma'or, Zeev; Leshem, Yael; Verochovsky, Lilian; Neuman, Rami; Brégégère, François Menahem; Milner, Yoram

    2008-10-01

    The aging process and its characterization in keratinocytes have not been studied in depth until now. We have assessed the cellular and molecular characteristics of aged epidermal keratinocytes in monolayer cultures and in skin by measuring their morphological, fluorometric and biochemical properties. Light and electron microscopy, as well as flow cytometry, revealed increase in cell size, changes in cell shape, alterations in mitochondrial structure and cytoplasmic content with aging. We showed that the expression of 16 biochemical markers was altered in aged cultured cells and in tissues, including caspases 1 and 3 and beta-galactosidase activities, immunoreactivities of p16, Ki67, 20S proteasome and effectors of the Fas-dependent apoptotic pathway. Aged cells diversity, and individual variability of aging markers, call for a multifunctional assessment of the aging phenomenon, and of its modulation by drugs. As a test case, we have measured the effects of Dead Sea minerals on keratinocyte cultures and human skin, and found that they stimulate proliferation and mitochondrial activity, decrease the expression of some aging markers, and limit apoptotic damage after UVB irradiation.

  19. Quantitative assessment of glacial fluctuations in the level of Lake Lisan, Dead Sea rift

    Science.gov (United States)

    Rohling, Eelco J.

    2013-06-01

    A quantitative understanding of climatic variations in the Levant during the last glacial cycle is needed to support archaeologists in assessing the drivers behind hominin migrations and cultural developments in this key region at the intersection between Africa and Europe. It will also foster a better understanding of the region's natural variability as context to projections of modern climate change. Detailed documentation of variations in the level of Lake Lisan - the lake that occupied the Dead Sea rift during the last glacial cycle - provides crucial climatic information for this region. Existing reconstructions suggest that Lake Lisan highstands during cold intervals of the last glacial cycle represent relatively humid conditions in the region, but these interpretations have remained predominantly qualitative. Here, I evaluate realistic ranges of the key climatological parameters that controlled lake level, based on the observed timing and amplitudes of lake-level variability. I infer that a mean precipitation rate over the wider catchment area of about 500 mm y-1, as proposed in the literature, would be consistent with observed lake levels if there was a concomitant 15-50% increase in wind speed during cold glacial stadials. This lends quantitative support to previous inferences of a notable increase in the intensity of Mediterranean (winter) storms during glacial periods, which tracked eastward into the Levant. In contrast to highstands during ‘regular’ stadials, lake level dropped during Heinrich Events. I demonstrate that this likely indicates a further intensification of the winds during those times.

  20. Anatomy of the dead sea transform from lithospheric to microscopic scale

    Science.gov (United States)

    Weber, M.; Abu-Ayyash, K.; Abueladas, A.; Agnon, A.; Alasonati-Tasarova, Z.; Al-Zubi, H.; Babeyko, A.; Bartov, Y.; Bauer, K.; Becken, M.; Bedrosian, P.A.; Ben-Avraham, Z.; Bock, G.; Bohnhoff, M.; Bribach, J.; Dulski, P.; Ebbing, J.; El-Kelani, R.; Forster, A.; Forster, H.-J.; Frieslander, U.; Garfunkel, Z.; Goetze, H.J.; Haak, V.; Haberland, C.; Hassouneh, M.; Helwig, S.; Hofstetter, A.; Hoffmann-Rotrie, A.; Jackel, K.H.; Janssen, C.; Jaser, D.; Kesten, D.; Khatib, M.; Kind, R.; Koch, O.; Koulakov, I.; Laske, Gabi; Maercklin, N.; Masarweh, R.; Masri, A.; Matar, A.; Mechie, J.; Meqbel, N.; Plessen, B.; Moller, P.; Mohsen, A.; Oberhansli, R.; Oreshin, S.; Petrunin, A.; Qabbani, I.; Rabba, I.; Ritter, O.; Romer, R.L.; Rumpker, G.; Rybakov, M.; Ryberg, T.; Saul, J.; Scherbaum, F.; Schmidt, S.; Schulze, A.; Sobolev, S.V.; Stiller, M.; Stromeyer, D.; Tarawneh, K.; Trela, C.; Weckmann, U.; Wetzel, U.; Wylegalla, K.

    2009-01-01

    Fault zones are the locations where motion of tectonic plates, often associated with earthquakes, is accommodated. Despite a rapid increase in the understanding of faults in the last decades, our knowledge of their geometry, petrophysical properties, and controlling processes remains incomplete. The central questions addressed here in our study of the Dead Sea Transform (DST) in the Middle East are as follows: (1) What are the structure and kinematics of a large fault zone? (2) What controls its structure and kinematics? (3) How does the DST compare to other plate boundary fault zones? The DST has accommodated a total of 105 km of leftlateral transform motion between the African and Arabian plates since early Miocene (???20 Ma). The DST segment between the Dead Sea and the Red Sea, called the Arava/ Araba Fault (AF), is studied here using a multidisciplinary and multiscale approach from the ??m to the plate tectonic scale. We observe that under the DST a narrow, subvertical zone cuts through crust and lithosphere. First, from west to east the crustal thickness increases smoothly from 26 to 39 km, and a subhorizontal lower crustal reflector is detected east of the AF. Second, several faults exist in the upper crust in a 40 km wide zone centered on the AF, but none have kilometer-size zones of decreased seismic velocities or zones of high electrical conductivities in the upper crust expected for large damage zones. Third, the AF is the main branch of the DST system, even though it has accommodated only a part (up to 60 km) of the overall 105 km of sinistral plate motion. Fourth, the AF acts as a barrier to fluids to a depth of 4 km, and the lithology changes abruptly across it. Fifth, in the top few hundred meters of the AF a locally transpressional regime is observed in a 100-300 m wide zone of deformed and displaced material, bordered by subparallel faults forming a positive flower structure. Other segments of the AF have a transtensional character with small pull

  1. Impact of paleoclimate on the distribution of microbial communities in the subsurface sediment of the Dead Sea.

    Science.gov (United States)

    Thomas, C; Ionescu, D; Ariztegui, D

    2015-11-01

    A long sedimentary core has been recently retrieved from the Dead Sea Basin (DSB) within the framework of the ICDP-sponsored Dead Sea Deep Drilling Project. Contrasting climatic intervals were evident by distinctive lithological facies such as laminated aragonitic muds and evaporites. A geomicrobiological investigation was conducted in representative sediments of this core. To identify the microbial assemblages present in the sediments and their evolution with changing depositional environments through time, the diversity of the 16S rRNA gene was analyzed in gypsum, aragonitic laminae, and halite samples. The subsurface microbial community was largely dominated by the Euryarchaeota phylum (Archaea). Within the latter, Halobacteriaceae members were ubiquitous, probably favored by their 'high salt-in' osmotic adaptation which also makes them one of the rare inhabitants of the modern Dead Sea. Bacterial community members were scarce, emphasizing that the 'low salt-in' strategy is less suitable in this environment. Substantial differences in assemblages are observed between aragonitic sediments and gypsum-halite ones, independently of the depth and salinity. The aragonite sample, deposited during humid periods when the lake was stratified, consists mostly of the archaeal MSBL1 and bacterial KB1 Candidate Divisions. This consortium probably relies on compatible solutes supplied from the lake by halotolerant species present in these more favorable periods. In contrast, members of the Halobacteriaceae were the sole habitants of the gypsum-halite sediments which result from a holomictic lake. Although the biomass is low, these variations in the observed subsurface microbial populations appear to be controlled by biological conditions in the water column at the time of sedimentation, and subsequently by the presence or absence of stratification and dilution in the lake. As the latter are controlled by climatic changes, our data suggest a relationship between local

  2. The Dead Sea Rift, a key to the tectonic link between the NeoTethys closure of and opening of the Red Sea

    Science.gov (United States)

    Mart, Y.

    2009-04-01

    The closure of the central NeoTethys Ocean took place progressively as the subduction of the oceanic lithosphere off Africa-Arabia gradually changed into collision, advancing southeastwards along the Zagros front since the early Miocene. That subduction-collision is contemporaneous with the opening of the Red Sea, and structural modeling suggested that the oblique convergence along frontal Arabia formed extensional stresses in the Arabia-Africa plate which matured in time to become the tectonic plate boundaries of the Gulf of Aden and the Red Sea (Bellahsen et al., 2003). However such marine basins are not known to occur along subducting plates, and the contemporaneity of the Zagros collision and the Red Sea extension could have been tectonically unrelated. Fortuitously the key to the tectonic linkage between the opening of the Red Sea and the closure of the NeoTethys can be found in the Dead Sea Rift. The tectonics of the Dead Sea Rift has been debated for decades to be interpreted either as a transform fault or an extensional rift, both extending from the northern Red Sea. The transform fault interpretation requires the Dead Sea structure to be contemporaneous with the Red Sea, whereas if it is an extensional rift, its structural development should be subsequent to that of the the Suez Rift. It is well established that the Red Sea and its extension in the Suez Rift developed during the Miocene. However, the reconstruction of the Miocene river drainage of the Levant shows that large rivers flowed then from NW Arabia to the Mediterranean, predating the Dead Sea Rift. This sequence of events sets the structural evolution of the dead Sea Rift to the Plio-Quaternary. The Rift is thus contemporaneous with the termination of the tectonic activity of the Gulf of Suez, indicating a clockwise rotation of the regional stress field in the last 5 Ma. These observation suggest that the extensional stresses caused by the gradual change from subduction to collision along the

  3. Continuous Dilution of the Ca-Chloride Dead Sea Bottom Brine during the Last Glacial - Evidence from Porewater from the ICDP Core

    Science.gov (United States)

    Levy, E. J.; Sivan, O.; Yechieli, Y.; Stein, M.; Lazar, B.; Gavrieli, I.

    2014-12-01

    The major ions composition of porewater extracted from core catchers collected along the ~450 m of the ICDP Dead Sea Deep core represents the chemical composition of the deepest parts of the terminal-hypersaline lakes that occupied the basin over the last 220 ka. Profiles of the conservative elements Br- and Mg2+ show that the deep brine underwent a steady long-term dilution during the time interval starting from the thick halite lithological section deposited at 123Kya (MIS 5e) and ending at the halite section deposited at <11Kya (MIS 1). The halite layers were deposited during extreme arid conditions during which lake level dropped dramatically and deep brine salinity rose substantially. The secular variation in Br- and Mg2+, the occurrences of major halite deposition events correlates extremely well with the 100Ky Milankovich cycle and the global benthic δ18O LR04 stack paleoclimate proxy (Lisiecki and Raymo, 2005). The freshening of the lake between the two extreme arid events must have been accompanied by dramatic water level rise and the establishment of long term stratification of the water column. The dilution of the brine was also accompanied by increase in the Na/Cl ratio, indicative of halite dissolution, most likely from the salt diaper of Mt. Sedom, which at the high lake stand was in contact with the brine and therefore susceptible to dissolution. The halite dissolved during the high stand of the last interglacial supplied the Na and Cl for the precipitation of halite during the post-glacial extreme arid event. Freshening of the hypolimnion and rise in Na/Cl took place mostly through turbulent mixing between the epilimnion and the deep hypolimnic water. The turbulent mixing with fresher epilimnetic brine, dropped the density of the hypolimnion from 1.25 g•cm-3 at 123Kya (MIS 5e) to 1.18 g•cm-3 at 16Kya, suggesting that the density of the epilimnion was even lower. A sharp lake level drop sometime after 16Kya lead to salinity rise of the

  4. Quantitative Assessment of In-situ Salt Karstification Using Shear Wave Velocity, Dead Sea

    Science.gov (United States)

    Ezersky, Michael; Legchenko, Anatoly

    2014-09-01

    The Dead Sea (DS) coastal areas have been dramatically affected by sinkhole formation since around 1990. Such sinkholes along both Israeli and Jordanian shores are linked to karst cavities that form through slow salt dissolution. A quantitative estimate of such in-situ salt karstification would be an important indicator of sinkhole hazard. One of the indications of salt karstification is its increased hydraulic conductivity, caused by the development of dissolution cavities forming conducting channels within the salt layer. We measured the hydraulic conductivity (K) versus shear-wave velocity (Vs) of DS salt in situ for estimating the actual salt karstification in areas of sinkhole development. These parameters were measured with the Magnetic Resonance Sounding (MRS) and Multichannel Analysis of Surface Waves (MASW) methods, respectively. Understanding of the field relationships was augmented by similar inter-relations obtained in the laboratory on samples of DS salt. In-situ salt velocities Vs vary from 750 m/s to over 1650 m/s, while hydraulic conductivity (K) in the same zones varies between about 10- 4 m/s to slightly over 10- 8 m/s. Both field and laboratory K and Vs values fit the exponential function ln(K) = - 0.0045 ∗ Vs - 5.416 with a determination coefficient (R2) of 0.88. A classification based on Vs and K was generated for salt conditions and the corresponding degrees of sinkhole hazard, which was verified in the Mineral Beach sinkhole development area. The mapping of sinkhole sites shows that they form within highly conductive zones with K ≥ 5.5 ∗ 10- 5. It is suggested that this methodology, with some modification, can be used for evaluating the conductive properties of karstified rock and associated sinkhole hazards.

  5. Faulted Tell and ancient road by the Dead Sea Transform in southern Turkey

    Science.gov (United States)

    Altunel, E.; Meghraoui, M.; Akyuz, S.; Karabacak, V.; Bertrand, S.; Yalciner, C.; Ferry, M.; Munschy, M.

    2006-12-01

    We investigate the northern end of the Dead Sea Transform Fault (DSTF) in the Amik Basin using paleoseismology, archeoseismology and geophysical prospecting. The DSFZ is one of the major continental faults where large historical earthquakes occurred, some of them were associated with surface ruptures. The Amik Basin has a large number of archaeological sites where some ancient man-made structures are located on the fault zone. The fault appears as a prominent scarp located immediately south of the basin and offsets large and small streams showing a range of 650 +-10 m to 14 +-0.5 m of left-lateral displacement. Aerial photographs and field observations indicate that the fault also affects Holocene lacustrine deposits of the basin and form a North-South trending morphological scarp. Archeological sites are largely spread in the area and the fault crosses the approximately 6500 BC old Sicantarla Tell and related walls. A total left-lateral offset of 40 +-5 m measured from the detailed morphology of the Tell and 43 +-1.5 m from a magnetic survey illustrates the cumulative left-lateral movement along the fault and provide with an average 5 mm/yr slip rate for the late Holocene. Field studies also showed that an ancient road with nearby Hittites inscriptions (around 2000 BC) is left-laterally offset by 25 +-2 m along the DSTF and provide with an average 6.2 mm/yr slip rate. In addition, paleoseismic trenching at three locations between the Tell and the southern fault trace expose the fault zone and successive most recent faulting events including the AD 1408 large earthquake. The faulted archeological sites and geomorphology offer the possibility to document successive coseismic ruptures and constitute a real archive of large earthquakes along the DSTF.

  6. Comparison of Geodetic and Late Pleistocene Slip Rates for the Southern Dead Sea Fault System

    Science.gov (United States)

    Cochran, W. J.; Gomez, F.; Abu Rajab, J. S.; Al-Tarazi, E.

    2012-12-01

    Comparisons of short-term (geodetic) and Late Quaternary slip rates have been used to assess time-variable fault kinematics along various active faults, globally. Differences between such types slip rates may have implications for crustal rheology and/or temporal variations in plate motion. This research aims to compare the geodetically-derived slip rates with slip rates based on Late Pleistocene landforms along the southern Dead Sea fault system (DSFS). The DSFS is an active, left-lateral transform that accommodates differential movement between the Arabian and Sinai plates. A number of slip rates have been previously reported ranging from 2 to 6mm/yr. However, comparison of various slip rates requires ensuring that associated uncertainties are assessed using a standard. New GPS velocities from Jordan are combined with other available GPS data, and are used to model slip rates using elastic block models. Resulting slip rates are 4.3 to 5.3 mm/yr with fault locking depths of 8 - 15 km. Late Pleistocene rates are assessed from published observations, as well as new data. New mapping of offset alluvial fans in the southern Wadi Araba was facilitated by multi-spectral imagery and high-resolution digital elevation model. These fans correlate with regional aggradation events, with the resulting Late Pleistocene slip rates ranging from 4.2 to 5.1 mm/yr. Statistically, the geodetic and neotectonic slip rates are identical. Additionally, a 3-dimensional slip vector for the last earthquake in the northern Wadi Araba is constructed using close-range photogrammetry of a faulted Byzantine aqueduct that indicates both horizontal and vertical displacements. Previous studies suggested characteristic earthquake slip, so slip rates and this slip vector provide a means of assessing mean EQ recurrence interval, as well as the role of earthquakes in constructing the long-term topography along this part of the transform.

  7. Rheological characterization of hair shampoo in the presence of dead sea salt.

    Science.gov (United States)

    Abu-Jdayil, B; Mohameed, H A; Sa'id, M; Snobar, T

    2004-02-01

    In Jordan, a growing industry has been established to produce different types of Dead Sea (DS) cosmetics that have DS salt (contains mainly NaCl, KCl, and MgCl(2)) in their formulas. In this work, the effect of DS salt on the rheology of hair shampoo containing the sodium lauryl ether sulfate as a main active matter was studied. The effects of DS salt and active matter concentration, and the temperature and time of salt mixing, on the rheological properties of hair shampoo were investigated. The salt-free shampoo showed a Newtonian behavior at 'low active matter' (LAM) and shear thinning at 'high active matter' (HAM). The presence of DS salt changed the rheological behavior of LAM shampoo from Newtonian (for the salt-free shampoo) to shear thinning. On the other hand, the behavior of HAM shampoo switched from shear thinning to Newtonian behavior in the presence of high concentration of DS salt. The addition of DS salt increased the apparent viscosity of shampoo to reach a maximum value that corresponded to a salt concentration of 1.5 wt.%. Further addition of DS salt led to a decrease in the shampoo viscosity to reach a value less than that of the salt-free sample at high salt concentration. Changing the mixing temperature (25-45 degrees C) and mixing time (15-120 min) of DS salt with shampoo has no significant influence on the rheological behavior. However, the mixing process increased the apparent viscosity of salt-free shampoo. The power law model fitted well the flow curves of hair shampoo with and without DS salt.

  8. Geodynamics of the Dead Sea Fault: Do active faulting and past earthquakes determine the seismic gaps?

    Science.gov (United States)

    Meghraoui, Mustapha

    2014-05-01

    The ~1000-km-long North-South trending Dead Sea transform fault (DSF) presents structural discontinuities and includes segments that experienced large earthquakes (Mw>7) in historical times. The Wadi Araba and Jordan Valley, the Lebanese restraining bend, the Missyaf and Ghab fault segments in Syria and the Ziyaret Fault segment in Turkey display geometrical complexities made of step overs, restraining and releasing bends that may constitute major obstacles to earthquake rupture propagation. Using active tectonics, GPS measurements and paleoseismology we investigate the kinematics and long-term/short term slip rates along the DSF. Tectonic geomorphology with paleoseismic trenching and archeoseismic investigations indicate repeated faulting events and left-lateral slip rate ranging from 4 mm/yr in the southern fault section to 6 mm/yr in the northern fault section. Except for the northernmost DSF section, these estimates of fault slip rate are consistent with GPS measurements that show 4 to 5 mm/yr deformation rate across the plate boundary. However, recent GPS results showing ~2.5 mm/yr velocity rate of the northern DSF appears to be quite different than the ~6 mm/yr paleoseismic slip rate. The kinematic modeling that combines GPS and seismotectonic results implies a complex geodynamic pattern where the DSF transforms the Cyprus arc subduction zone into transpressive tectonics on the East Anatolian fault. The timing of past earthquake ruptures shows the occurrence of seismic sequences and a southward migration of large earthquakes, with the existence of major seismic gaps along strike. In this paper, we discuss the role of the DSF in the regional geodynamics and its implication on the identification of seismic gaps.

  9. Earthquake-induced barium anomalies in the Lisan Formation, Dead Sea Rift valley, Israel

    Science.gov (United States)

    Katz, Amitai; Agnon, Amotz; Marco, Shmuel

    2009-08-01

    Prominent barium concentration anomalies that appear within earthquake brecciated layers (seismites) in the late Pleistocene lacustrine Lisan Formation in the Dead Sea Basin (DSB) are described and discussed here for the first time. Chemical analyses of samples from vertical profiles through the seismites display asymmetric Ba concentration peaks. The peaks start a few centimeters above the seismite's base and gradually rise to maxima reaching some 1000 ppm Ba, before falling off to background values (around 100 ppm), or abutting against the upper boundary of the breccia layer. High resolution SEM and electron microprobe analyses disclose that the Ba in the anomalies resides within prismatic crystallites (mostly sorting relationship with the latter. The peaks of the anomalies reflect higher population density, rather than larger crystal sizes, of the BM crystallites therein. Mass balance calculations show that the mass of Ba 2+ dissolved in the lake above a unit area of the seismites was mostly several times larger than that found in the seismite. The concentration of Ba 2+ in DSB Ca-chloride brines is mostly lesser than that in the DSB Lake, ruling out the former as a source of Ba to the anomalies. We propose that, during earthquakes, the uppermost bottom sediment layers in the DSB Lake were shaken and re-suspended into the overlying brine. The larger, faster-settling fragments and grains remained almost intact or were rapidly removed, unaffected, from the slurry. However, the finer grains remained in suspension for longer periods, allowing nucleation and growth of BM crystallites on their surfaces from the surrounding brine before reaching the bottom. The lag of Ba trapping behind the breccia accumulation and the asymmetrical peak shapes of the anomalies are accounted for by decreasing dilution of the Ba-rich finer particles by Ba-poor coarse grains during seismite accumulation, as reflected by the graded bedding of the seismite layers. The supply rate of Ba 2

  10. Characterization of seepage surfaces from Space-borne radar interferometry stacking techniques, Southern Dead Sea area, Jordan

    Science.gov (United States)

    Tessari, Giulia; Closson, Damien; Abou Karaki, Najib; Atzori, Simone; Fiaschi, Simone; Floris, Mario; Pasquali, Paolo; Riccardi, Paolo

    2014-05-01

    The Dead Sea is a terminal lake located in a pull-apart basin of the Dead Sea Transform fault zone. It is the lowest emerged place on Earth at about -428 m bsl. Since the 1960s, the over-pumping of its tributaries leads to a decrease in the water level. Eventually, it became more pronounced decades after decades. In 2014, it is more than 1m/year. The overall drop is around 33 m. With salinity ten times greater than the ocean water one, the lake body and its underground lateral extensions act as a high density layer over which the fresh ground waters are in hydrostatic equilibrium. The slope of the interface between saline and fresh waters is ten times shallower than normally expected near the ocean. According to a number of wells along the Jordanian Dead Sea coast, the water table level does not drop at the same speed than the Dead Sea. An increasingly important gradient is constantly being created along the coastal zone. In many places, the fresh ground waters move very rapidly towards the base level to compensate for the imbalance. This statement is supported by a body of observations: a) appearance of vegetation (Tamarisk) in arid areas (precipitation: 50 to 70 mm/year) dominated by salt deposits such as the Lisan peninsula; b) presence of submarine circular collapses visible along the coast. Their diameters decreasing with distance from the shore line; c) appearances of springs and recurring landslides along the coast. With the exception of the submarine features, all these elements are located in the land strip that emerged progressively from the 1960s, 33 m in elevation, ranging from a few decameters up to several kilometers wide. In many places, the surface is characterized by superficial seepages causing subtle to very pronounced subsidence, and sinkholes. In this contribution, we show that advanced differential radar interferometry techniques applied to ERS, ENVISAT and COSMO-SkyMed images stacks are able to underscore the most affected places. The mapping

  11. Precipitation regimes in the Levant during the Holocene inferred from Dead Sea lake levels and stochastic modeling

    Science.gov (United States)

    Morin, Efrat; Ryb, Tamar; Gavrieli, Ittai; Enzel, Yehouda

    2016-04-01

    The Dead Sea is a terminal lake of one of the largest watersheds in the Levant (~43,000 square km), draining sub-humid to hyperarid climate zones. The large size of the watershed and the synchronous regional pattern of annual precipitation are the main reasons that the Dead Sea lake levels are good proxies for the Levant precipitation. Since the mid-1960s intensive water diversions from this watershed caused a dramatic human-induced level drop (currently >1 m/year). Holocene lake levels were used to infer regional precipitation regimes. Previous studies have associated lake level rises and drops with past wet and dry periods in the region, but their quantitative assessment remains a challenge. Moreover, the attributing of lake levels alterations to changes in precipitation regime still misses natural precipitation variability and there is a need to identify and separate their effects. The current study confronts these basic challenges that underlie the transfer of proxy to climatic parameter procedures. It uses here a unique stochastic framework under which we link precipitation regime with the Dead Sea lake levels, considering changes and trends in both mean and variance. Then we infer Levant precipitation regime during the Holocene. The present mean and variance of annual precipitation and lake levels are represented by (a) Kfar Giladi rain station, determined as the best correlated with natural Dead Sea lake level changes, and, (b) using a water balance model; this allowed simulating mean and variance of annual lake levels. Stochastic simulations included scenarios of changes in precipitation regime considering both constant and trended mean annual precipitation. We assessed probabilities of obtaining specific rises and drops, derived from reconstructed Holocene lake levels, under diverse scenarios. The results suggest that late Holocene precipitation regime could be governed by periods of increasing and decreasing trends of mean annual precipitation in the

  12. Communicating mega-projects in the face of uncertainties: Israeli mass media treatment of the Dead Sea Water Canal.

    Science.gov (United States)

    Fischhendler, Itay; Cohen-Blankshtain, Galit; Shuali, Yoav; Boykoff, Max

    2015-10-01

    Given the potential for uncertainties to influence mega-projects, this study examines how mega-projects are deliberated in the public arena. The paper traces the strategies used to promote the Dead Sea Water Canal. Findings show that the Dead Sea mega-project was encumbered by ample uncertainties. Treatment of uncertainties in early coverage was dominated by economics and raised primarily by politicians, while more contemporary media discourses have been dominated by ecological uncertainties voiced by environmental non-governmental organizations. This change in uncertainty type is explained by the changing nature of the project and by shifts in societal values over time. The study also reveals that 'uncertainty reduction' and to a lesser degree, 'project cancellation', are still the strategies most often used to address uncertainties. Statistical analysis indicates that although uncertainties and strategies are significantly correlated, there may be other intervening variables that affect this correlation. This research also therefore contributes to wider and ongoing considerations of uncertainty in the public arena through various media representational practices. © The Author(s) 2013.

  13. Modelling of a strong dust event in the complex terrain of the Dead Sea valley during the passage of a gust front

    Directory of Open Access Journals (Sweden)

    Pavel Kishcha

    2016-02-01

    Full Text Available The area of the Dead Sea valley and the adjacent regions are often affected by mineral dust. This study focuses on an extreme dust episode occurring on 22 March 2013, where near-surface dust concentrations of up to 7000 µg m−3 were encountered in the Dead Sea region. This episode is of great interest as it was accompanied by high wind speeds and a gust front that rapidly passed the Judean Mountains. Wind was even accelerated on the lee side of the Judean Mountains leading to a severe downslope wind. We simulated this situation with the comprehensive online-coupled weather forecast model COSMO-ART. Fair agreement was found between the simulated meteorological variables and the observations. The model was capable of producing a reasonable spatiotemporal distribution of near-surface dust concentration, consistent with available measurements in this area. With respect to the time of the maximum near-surface dust concentration in the Dead Sea valley, the model captured it almost perfectly compared to the observed total suspended particle (TSP concentrations. COSMO-ART showed that the high near-surface dust concentration in the Dead Sea valley was mainly determined by local emissions. These emissions were caused by strong winds on the lee side of the Judean Mts. The model showed that an ascending airflow in the Dead Sea valley lifted dust particles, originating mainly from the upwind side of the Judean Mts., up to approximately 7 km. These dust particles contributed to the pronounced maximum in modelled dust aerosol optical depth (AOD over the valley. Here we highlight the important point that the simulated maximum dust AOD was reached in the eastern part of the Dead Sea valley, while the maximum near-surface dust concentration was reached in the western part of the valley.

  14. The extent of seawater circulation in the aquifer and its role in elemental mass balances: A lesson from the Dead Sea

    Science.gov (United States)

    Kiro, Yael; Weinstein, Yishai; Starinsky, Abraham; Yechieli, Yoseph

    2014-05-01

    This paper shows for the first time a field-based estimation of the volume of dispersive density-driven long-term seawater circulation in coastal aquifers, which is crucial to the understanding of water-rock interaction and to the assessment of its potential impact on elemental mass balances in the sea. The Dead Sea is an ideal place for studying this type of circulation due to the absence of tides and the accessibility of the shallow fresh-saline transition zone. The unique antithetical behavior of 226Ra and 228Ra during seawater circulation in the Dead Sea aquifer, where 228Ra is added and 226Ra is removed, provides a robust new method for quantifying aquifer circulation. Here we estimate water circulation through the Dead Sea aquifer to be 400 million m3/yr (˜2.5 million m3/yr per 1 km of shoreline), which is ˜20% of the fresh water inflow prior to the 1960s. This large volume can affect trace element concentrations in the Dead Sea, e.g. it is a sink for 226Ra, Ba and U and a source for 228Ra and Fe. These results suggest that dispersive density-driven seawater circulation in aquifers may play an important role in mass balances in other lacustrine and oceanic settings.

  15. Biodegradation of aromatic hydrocarbons by Haloarchaea and their use for the reduction of the chemical oxygen demand of hypersaline petroleum produced water.

    Science.gov (United States)

    Bonfá, Maricy R L; Grossman, Matthew J; Mellado, Encarnacion; Durrant, Lucia R

    2011-09-01

    Ten halophilic Archaea (Haloarchaea) strains able to degrade aromatic compounds were isolated from five hypersaline locations; salt marshes in the Uyuni salt flats in Bolivia, crystallizer ponds in Chile and Cabo Rojo (Puerto Rico), and sabkhas (salt flats) in the Persian Gulf (Saudi Arabia) and the Dead Sea (Israel and Jordan). Phylogenetic identification of the isolates was determined by 16S rRNA gene sequence analysis. The isolated Haloarchaea strains were able to grow on a mixture of benzoic acid, p-hydroxybenzoic acid, and salicylic acid (1.5mM each) and a mixture of the polycyclic aromatic hydrocarbons, naphthalene, anthracene, phenanthrene, pyrene and benzo[a]anthracene (0.3mM each). Evaluation of the extent of degradation of the mixed aromatic hydrocarbons demonstrated that the isolates could degrade these compounds in hypersaline media containing 20% NaCl. The strains were shown to reduce the COD of hypersaline crude oil reservoir produced waters significantly beyond that achieved using standard hydrogen peroxide treatment alone. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Climatotherapy at the Dead Sea: an effective treatment modality for atopic dermatitis with significant positive impact on quality of life.

    Science.gov (United States)

    Adler-Cohen, Chagit; Czarnowicki, Tali; Dreiher, Jacob; Ruzicka, Thomas; Ingber, Arieh; Harari, Marco

    2012-01-01

    Atopic dermatitis (AD) has an appreciable effect on quality of life. Improving the quality of life of AD patients is a priority. This study aimed to evaluate the impact of Dead Sea climatotherapy (DSC) as a treatment of AD and its influence on the quality of life of these patients. Forty-nine adult patients with AD treated during the years 2009-2010 at the Deutsches Medizinisches Zentrum Medical Center participated in this prospective study. Climatotherapy was administered in accordance with a computer-designed protocol and included gradually increased sun exposure after a sea bath. Severity of AD was evaluated using the Scoring Atopic Dermatitis (SCORAD) index. Patient quality of life was evaluated using Skindex-29. Statistical analysis was performed using a paired t test and Wilcoxon and Mann-Whitney U tests. After treatment, the mean SCORAD value improved by 39 points (P Sea climatotherapy provides an effective treatment modality for AD by improving the patient's skin condition and quality of life.

  17. Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform

    Science.gov (United States)

    Maercklin, N.; Bedrosian, P.A.; Haberland, C.; Ritter, O.; Ryberg, T.; Weber, M.; Weckmann, U.

    2005-01-01

    Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ???10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it, and the boundary between the two units coincides partly with a seismic scattering image. At 1-4 km depth the boundary is offset to the east of the AF surface trace, suggesting that at least two fault strands exist, and that slip occurred on multiple strands throughout the margin's history. A westward fault jump, possibly associated with straightening of a fault bend, explains both our observations and the narrow fault zone observed by others. Copyright 2005 by the American Geophysical Union.

  18. Two recent but temporally distinct outbreaks of cutaneous leishmaniasis among foreign workers in the Dead-Sea area of Jordan.

    Science.gov (United States)

    Mosleh, I M; Geith, E; Schönian, G; Kanani, K A

    2009-07-01

    Two temporally distinct outbreaks of human cutaneous leishmaniasis (CL), as well as scattered cases of the disease, have recently been observed close to the Dead Sea, in Jordan. Each of the two outbreaks, which occurred in 2004/2005 and 2007/2008, involved a group of foreign workers who were deployed within otherwise uninhabited locations. During each outbreak, about 20% of the workers were found infected with the causative parasite. In the earlier outbreak, 61 workers were found to have skin lesions like those of CL and all but three were confirmed by culture and/or the examination of smears (40 cases) or, in the case of 18 (86%) of the 21 suspected cases found smear- and culture-negative, by PCR. In the second outbreak, the cases were only identified from their clinical manifestations and their response to antileishmanial treatment (cryotherapy). Leishmania major was identified as the cause of the 2004/2005 outbreak and some sporadic cases that occurred, in 2004, along the shores of the Dead Sea. The burrows of potential reservoir hosts were found close to the outbreak locations, frequently under the chenopod Seidlitzia rosmarinus. The two outbreaks emphasise the continuing problem posed by the CL focus in the Mid Jordan Valley and its impact on humans who move into the area. Curiously, an investigation on the socio-economic conditions of the workers during the outbreaks identified a group of 48 workers who were living in air-conditioned rooms during the 2007/2008 outbreak, among whom no CL cases were found. In contrast, 26 of a neighbouring group of 124 workers, who were all living in non-air-conditioned rooms, developed CL lesions. The role of air conditioning, and of other factors and measures, in the prevention of the transmission of the causative parasites of CL merits further investigation and the attention of the local health authorities.

  19. THE EFFECTS OF POSSIBLE CONTAMINATION ON THE RADIOCARBON DATING OF THE DEAD SEA SCROLLS II : EMPIRICAL METHODS TO REMOVE CASTOR OIL AND SUGGESTIONS FOR REDATING

    NARCIS (Netherlands)

    Rasmussen, Kaare Lund; van der Plicht, Johannes; Doudna, Gregory; Nielsen, Frederik; Hojrup, Peter; Stenby, Erling Halfdan; Pedersen, Carl Th; Højrup, Peter

    2009-01-01

    While kept at the Rockefeller Museum in East Jerusalem, many Dead Sea Scroll fragments were exposed to castor oil by the original team of editors in the course of cleaning the parchments. Castor oil must be regarded as a serious contaminant in relation to radiocarbon dating. If modern castor oil is

  20. Isotopically heavy carbon in C21 to C25 regular isoprenoids in halite-rich deposits from the Sdm Formation, Dead Sea, Israel

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Grice, K.; Schouten, S.; Nissenbaum, A.; Charrach, J.

    1998-01-01

    A series of Miocene/Pliocene halite deposits (with extremely low organic carbon contents) from the Sdom Formation (Dead Sea Basin, Israel) have been studied. Distributions and contents of biomarkers have been determined using GC MS and irm-GCMS analyses, respectively. The hydrocarbon fractions

  1. Geometry and subsidence history of the Dead Sea basin: A case for fluid-induced mid-crustal shear zone?

    Science.gov (United States)

    ten Brink, Uri S.; Flores, C.H.

    2012-01-01

    Pull-apart basins are narrow zones of crustal extension bounded by strike-slip faults that can serve as analogs to the early stages of crustal rifting. We use seismic tomography, 2-D ray tracing, gravity modeling, and subsidence analysis to study crustal extension of the Dead Sea basin (DSB), a large and long-lived pull-apart basin along the Dead Sea transform (DST). The basin gradually shallows southward for 50 km from the only significant transverse normal fault. Stratigraphic relationships there indicate basin elongation with time. The basin is deepest (8-8.5 km) and widest (???15 km) under the Lisan about 40 km north of the transverse fault. Farther north, basin depth is ambiguous, but is 3 km deep immediately north of the lake. The underlying pre-basin sedimentary layer thickens gradually from 2 to 3 km under the southern edge of the DSB to 3-4 km under the northern end of the lake and 5-6 km farther north. Crystalline basement is ???11 km deep under the deepest part of the basin. The upper crust under the basin has lower P wave velocity than in the surrounding regions, which is interpreted to reflect elevated pore fluids there. Within data resolution, the lower crust below ???18 km and the Moho are not affected by basin development. The subsidence rate was several hundreds of m/m.y. since the development of the DST ???17 Ma, similar to other basins along the DST, but subsidence rate has accelerated by an order of magnitude during the Pleistocene, which allowed the accumulation of 4 km of sediment. We propose that the rapid subsidence and perhaps elongation of the DSB are due to the development of inter-connected mid-crustal ductile shear zones caused by alteration of feldspar to muscovite in the presence of pore fluids. This alteration resulted in a significant strength decrease and viscous creep. We propose a similar cause to the enigmatic rapid subsidence of the North Sea at the onset the North Atlantic mantle plume. Thus, we propose that aqueous fluid flux

  2. Thermal impacts of magmatic intrusions on dolomitization processes in the Tiberias Basin, Jordan-Dead Sea Transform

    Science.gov (United States)

    Koltzer, Nora; Möller, Peter; Inbar, Nimrod; Siebert, Christian; Rosenthal, Eliyahu; Al-Raggad, Marwan; Magri, Fabien

    2017-04-01

    The Tiberias Basin (TB) is located within the Jordan-Dead Sea Transform and is bordered to the west by the Lower Galilee (Israel), where Pliocene basalts cover an area of 35 km2. Hydrochemical analyses highlight that two types of brines exist around Lake Tiberias (LT) (Mandel 1965; Möller et al. 2009): (1) Along the eastern side of LT, brine is characterized by Mg/Ca>1, which resulted from evaporation of seawater during the Late Miocene, whereas (2) along the western side of the lake, brine is characterized by Mg/Caheated the formations, which build up the Lower Galilee, west of LT. As a result, the Cenomanian Formations, where the original brine is mostly buried, were only sufficiently heated in the eastern Galilee. In this study, we try to estimate to which extent and through which mechanisms fissure eruptions have induced heated brine to flow within the limestone aquifers. 2D simulations of coupled heat transport and fluid flow show that different aspects control the heat transport in the limestone aquifer. Preliminary results indicate that conductive heat transport generates sharp temperature fronts that extent 30 meters after 5 years of continuous magmatic intrusion from the fissures, ruling out heat conduction as a major mechanism for dolomitization. By contrast, convective cells in the Turonian and Cenomanian aquiferous formations have the potential to develop at different scales that depend on (a) hydraulic conductivity and porosity of the aquifer, (b) the orientation of the regional flow and (c) the topography of the aquifer. As a result of convective flow, brines surrounding a single fissure intrusion are heated more than 100 °C up to a width of 2 km in both directions. The thermally induced flow velocities are in the range of 2 m/year. In simulations with multiple intrusions, the thermal plume can stretch over 5.5 km. The simulations indicate that magmatic induced advective/convective heating may have generated temperature conditions favorable for

  3. Implications of S1 tephra findings in Dead Sea and Tayma palaeolake sediments for marine reservoir age estimation and palaeoclimate synchronisation

    Science.gov (United States)

    Neugebauer, Ina; Wulf, Sabine; Schwab, Markus J.; Serb, Johanna; Plessen, Birgit; Appelt, Oona; Brauer, Achim

    2017-08-01

    Here we report on the first findings of a cryptotephra in the Holocene lacustrine sediment records of the Dead Sea and Tayma palaeolake (NW Arabian Peninsula). The major element glass composition of this rhyolitic tephra is identical to the distal 'S1' tephra layer identified in the Yammoûneh palaeolake (Lebanon), in a marine sediment record from the SE Levantine basin and in the Sodmein Cave archaeological site in Egypt. The S1 tephra corresponds to the early Holocene 'Dikkartın' dome eruption of the Erciyes Dağ volcano in central Anatolia (Turkey) and has been dated in the marine record at 8830 ± 140 cal yr BP. We present new age estimates of the S1 tephra based on radiocarbon dating of terrestrial plant remains and pollen concentrates revealing ages of 8939 ± 83 cal yr BP in the Dead Sea sediments and 9041 ± 254 cal yr BP in Tayma. The precise date from the Dead Sea allows refining the early Holocene marine reservoir age in the SE Levantine Sea to ca. 320 ± 50 years. Synchronisation of marine and terrestrial palaeoclimate records in the eastern Mediterranean region using the S1 tephra further suggests a time-transgressive expansion of the early Holocene humid period.

  4. The complex karst dynamics of the Lisan Peninsula revealed by 25 years of DInSAR observations. Dead Sea, Jordan

    Science.gov (United States)

    Fiaschi, Simone; Closson, Damien; Abou Karaki, Najib; Pasquali, Paolo; Riccardi, Paolo; Floris, Mario

    2017-08-01

    This article presents and analyses the results obtained from Differential Interferometric Synthetic Aperture Radar (DInSAR) techniques applied to ERS-1/2, ENVISAT, ALOS-PALSAR, COSMO-SkyMed, and Sentinel-1A datasets over the Lisan Peninsula, located in the southern part of the Dead Sea, Jordan. The novelty comes from the integration of three different wavelengths to study the dynamics of a salt dome. The monitoring activity entirely covers the period extending from 1992 to 2016. Five displacement maps have been produced, carefully checked and then fused to provide a total cumulated map of the displacements in the area. The ground movements have been analysed by comparison with in-situ tectonic observations collected by various authors since the mid-1980s. The study shows an episodic rising of the Lisan diapir. The presented results can be useful to update the knowledge of the displacement rates occurring in the area and to better comprehend the complex dynamics of the Lisan Peninsula.

  5. 3D micro-XRF for cultural heritage objects: new analysis strategies for the investigation of the Dead Sea Scrolls.

    Science.gov (United States)

    Mantouvalou, Ioanna; Wolff, Timo; Hahn, Oliver; Rabin, Ira; Lühl, Lars; Pagels, Marcel; Malzer, Wolfgang; Kanngiesser, Birgit

    2011-08-15

    A combination of 3D micro X-ray fluorescence spectroscopy (3D micro-XRF) and micro-XRF was utilized for the investigation of a small collection of highly heterogeneous, partly degraded Dead Sea Scroll parchment samples from known excavation sites. The quantitative combination of the two techniques proves to be suitable for the identification of reliable marker elements which may be used for classification and provenance studies. With 3D micro-XRF, the three-dimensional nature, i.e. the depth-resolved elemental composition as well as density variations, of the samples was investigated and bromine could be identified as a suitable marker element. It is shown through a comparison of quantitative and semiquantitative values for the bromine content derived using both techniques that, for elements which are homogeneously distributed in the sample matrix, quantification with micro-XRF using a one-layer model is feasible. Thus, the possibility for routine provenance studies using portable micro-XRF instrumentation on a vast amount of samples, even on site, is obtained through this work.

  6. Natural versus human control on subsurface salt dissolution and development of thousands of sinkholes along the Dead Sea coast

    Science.gov (United States)

    Abelson, Meir; Yechieli, Yoseph; Baer, Gidon; Lapid, Gil; Behar, Nicole; Calvo, Ran; Rosensaft, Marcelo

    2017-06-01

    One of the most hazardous results of the human-induced Dead Sea (DS) shrinkage is the formation of more than 6000 sinkholes over the last 25 years. The DS shrinkage caused eastward retreat of underground brine replaced by fresh groundwater, which in turn dissolved a subsurface salt layer, to generate cavities and collapse sinkholes. The areal growth rate of sinkhole clusters is considered the most pertinent proxy for sinkholes development. Analysis of light detection and ranging, digital elevation models, and interferometric synthetic aperture radar allows translation of the areal growth rate to a salt dissolution rate of the salt layer, revealing two peaks in the history of the salt dissolution rate. These peaks cannot be attributed to the decline of the DS level. Instead, we show that they are related to long-term variations of precipitation in the groundwater source region, the Judea Mountains, and the delayed response of the aquifer system between the mountains and the DS rift. This response is documented by groundwater levels and salinity variations. We thus conclude that while the DS level decline is the major trigger for sinkholes formation, the rainfall variations more than 30 km to the west dominate their evolution rate. The influence of increasing rainfall in the Judea Mountains reaches the DS at a typical time lag of 4 years, and the resulting increase in the salt dissolution rate lags by a total time of 5-6 years.

  7. The tectonic framework of a complex pull-apart basin: Seismic reflection observations in the Sea of Galilee, Dead Sea transform

    Science.gov (United States)

    Hurwitz, S.; Garfunkel, Z.; Ben-Gai, Y.; Reznikov, M.; Rotstein, Y.; Gvirtzman, H.

    2002-01-01

    A multi-channel seismic reflection survey consisting of 20 lines with a total length of 180 km was conducted in the Sea of Galilee. The data provide new insights into the Pliocene-Quaternary evolution of the Kinarot-Beit-Shean pull-apart basin (KBSB) along the Dead Sea transform. Two distinct zones are defined beneath the lake: (1) a graben that underlies most of the lake, bounded by steep north-south longitudinal strike-slip faults and (2) shallow pre-rift units underlying the northwestern wider part of the lake. We suggest that before approximately 4 Ma, the KBSB grew due to northward movement of the Korazim Plateau and by crustal stretching along the rift axis. Since the Pliocene (??? 4 Ma), lateral slip has been transferred from the southern segment of the basin's western marginal fault to normal faults in the Galilee, and to the eastern margin of the Korazim Plateau by the newly formed, Almagor fault, which makes a restraining bend along the transform. N-S lithospheric stretching below the KBSB has diminished and the Korazim Plateau has changed from being a detached block to a compressional saddle. A phase of rapid subsidence, and formation of a half-graben structure in the northern part of the basin approximately 1 Ma ago was coeval with major deformation in areas adjacent to the KBSB, indicating major reorganization of the plate boundary in the region. Currently, most transform motions are probably taken up along a single fault on the eastern side of the KBSB, implying that the main trough under the Sea of Galilee is in a late stage of growth as a pull-apart. ?? 2002 Elsevier Science B.V. All rights reserved.

  8. Relationships between lake-level changes and water and salt budgets in the Dead Sea during extreme aridities in the Eastern Mediterranean

    Science.gov (United States)

    Kiro, Yael; Goldstein, Steven L.; Garcia-Veigas, Javier; Levy, Elan; Kushnir, Yochanan; Stein, Mordechai; Lazar, Boaz

    2017-04-01

    Thick halite intervals recovered by the Dead Sea Deep Drilling Project cores show evidence for severely arid climatic conditions in the eastern Mediterranean during the last three interglacials. In particular, the core interval corresponding to the peak of the last interglacial (Marine Isotope Stage 5e or MIS 5e) contains ∼30 m of salt over 85 m of core length, making this the driest known period in that region during the late Quaternary. This study reconstructs Dead Sea lake levels during the salt deposition intervals, based on water and salt budgets derived from the Dead Sea brine composition and the amount of salt in the core. Modern water and salt budgets indicate that halite precipitates only during declining lake levels, while the amount of dissolved Na+ and Cl- accumulates during wetter intervals. Based on the compositions of Dead Sea brines from pore waters and halite fluid inclusions, we estimate that ∼12-16 cm of halite precipitated per meter of lake-level drop. During periods of halite precipitation, the Mg2+ concentration increases and the Na+/Cl- ratio decreases in the lake. Our calculations indicate major lake-level drops of ∼170 m from lake levels of 320 and 310 m below sea level (mbsl) down to lake levels of ∼490 and ∼480 mbsl, during MIS 5e and the Holocene, respectively. These lake levels are much lower than typical interglacial lake levels of around 400 mbsl. These lake-level drops occurred as a result of major decreases in average fresh water runoff, to ∼40% of the modern value (pre-1964, before major fresh water diversions), reflecting severe droughts during which annual precipitation in Jerusalem was lower than 350 mm/y, compared to ∼600 mm/y today. Nevertheless, even during salt intervals, the changes in halite facies and the occurrence of alternating periods of halite and detritus in the Dead Sea core stratigraphy reflect fluctuations between drier and wetter conditions around our estimated average. The halite intervals include

  9. Molecular archaeology: Export of Dead Sea asphalt to Canaan and Egypt in the Chalcolithic-Early Bronze Age (4th-3rd millennium BC)

    Science.gov (United States)

    Connan, Jacques; Nissenbaum, Arie; Dessort, Daniel

    1992-07-01

    Nine archaeological bitumens from excavations in Canaan, Sinai and Egypt (Tel Irani, Ein Zik, Palmahim, Tel Arad, Jerusalem, Ein Besor-Site H, Sheik Awad and Maadi), dated 3900-2200 Bc. And two natural asphalts of the Dead Sea area (Ein Gedi floating blocks and Nahal Heimar) have been compared using the following geochemical techniques: chloroform extraction and GC and GC-MS analyses of C 15+ alkanes and C 15+ aromatics, isotopic analysis (δ 13C and δD) on chloroform extracts and asphaltenes and Rock-Eval pyrolysis of the insoluble organic residue. All samples are genetically related and are different from other archaeological bitumens from Syria and Iraq. Tel Irani archaeological bitumen was found to be identical to the floating block asphalts of the Dead Sea. Other archaeological bitumens were recognized as having been weathered and biodegraded to various degrees at archaeological sites in the course of the millennia. They are regarded as counterparts of floating block asphalts altered by aging. This study is the first evidence of the trade and export of raw bitumens from the Dead Sea area within Canaan and to Egyptian trading centers on the mainland route to Egypt between 3900 and 2200 BC, prior to the extensive utilization of bitumen for mummification in ancient Egypt.

  10. Contribution of Magnetic Resonance Sounding to karst aquifer characterization and sinkhole hazard evaluation on the Jordanian coast of the Dead Sea

    Science.gov (United States)

    Boucher, M.; Legchenko, A.; Ezersky, M.; Camerlynck, C.; Al-Zoubi, A.

    2012-04-01

    Since the 1970s, the water level of the Dead Sea has highly dropped causing the appearance of sinkholes along the shoreline both in Jordan and Israel. In South Jordan, the consequences are dramatic for farmers who exploit the land. The subsurface in this area is heterogeneous and composed of intercalated sand and clay layers over a salt rock, which is partly karstified. The appearance of sinkholes is known to be initiated by the emptying of karst cavities in depth. In order to identify the risk of collapse it is necessary to better understand the relations between the Dead Sea and the coastal aquifer. In this framework, the Ghor Al Haditha site was prospected by Magnetic Resonance Sounding (MRS). The MRS method is a non-invasive geophysical method that allows estimating the geometry, the porosity and the transmissivity of aquifers. On Ghor Al Haditha site, 3 MR soundings were performed in 2005 and repeated in 2007 and 12 additional soundings were carried out in 2007. The conductivity of the field (to 0.3-0.5 ohm.m in this context) was measured by TDEM on the same locations and was taken into account in the inversion of MRS data. We detected water saturated and permeable sediments (water content of 10-15% and permeability of 2.10-4-2.10-3 m/s) that is located at the salt formation (~40 m) deep. MRS results revealed also a hydraulic gradient towards the Dead Sea, indicating a flow of water from the sediment aquifer to the Dead Sea that rounds the salt (and karstic cavities). The hydraulic gradient is particularly high (~3%) in the area where sinkholes had appeared. This higher gradient can be explained by slightly lower MRS transmissivity (0.01-0.02 m/s2) in comparison with the part of the site without sinkhole (0.03-0.05m/s2). We suggest that the low transmissivities are probably due to the refilling of karst cavities by fine materials after sinkholes formations. Indeed, the MR sounding repeated 2 times and located in the close vicinity of an area that collapsed

  11. Late Holocene Paleoseismic Timing and Slip History Along the Missyaf Segment of the Dead Sea Fault in Syria

    Science.gov (United States)

    Meghraoui, M.; Gomez, F.; Sbeinati, R.; Van der Woerd, J.; Mouty, M.; Hijazi, F.; Darkal, A.; Darawcheh, R.; Radwan, Y.; Al-Najjar, H.; Layous, I.; Al-Ghazzi, R.; Barazangi, M.

    2001-12-01

    We investigate the timing of Holocene earthquakes and related slip rate along the main segment of the Dead Sea fault south of the Ghab pull-apart basin in western Syria. The 60-70 km long Missyaf segment consists of a single fault branch of the north-south trending left-lateral fault at the plate boundary between Africa and Arabia. The late Quaternary tectonic activity along the fault is characterized by (1) deflected streams with consistent left-lateral displacements of different sizes (50 to 300 m), and (2) evidence of large shutter-ridge structures and small pull-apart basins. Microtopographic surveys and trenching across the fault at two sites document the size and timing of paleoseismic events and the related faulting behavior. Near El Harif village, the fault cut across a Roman aqueduct (younger than 22 AD) and induces 10.5 ±0.1 m of left-lateral displacement. Nearby trench-excavations and test pits exhibit the fault with the shear zone affecting a succession of young alluvial deposits of a terrace meander. Radiocarbon dating of the faulting events with vertical displacements reveal the occurrence of a large seismic event prior to 408-380 BC, a penultimate event between 22 - 979 AD and the most recent event between 979 - 1255 AD. The two most recent events being most likely responsible for the Roman aqueduct total displacement, it implies an average coseismic left-lateral movement of 5 m and a slip rate of about 5 mm/yr. The correlation with the historical seismicity catalogue suggests that the most recent faulting event may correspond to the well documented large earthquake of 1170 AD.

  12. Late Holocene Paleoseismic Timing and Slip Rate Along The Missyaf Segment of The Dead Sea Fault In Syria

    Science.gov (United States)

    Meghraoui, M.; Gomez, F.; Sbeinati, R.; van der Woerd, J.; Mouty, M.; Darkal, A.; Darawcheh, R.; Radwan, Y.; Al-Ghazzi, R.; Barazangi, M.

    We investigate the timing of Holocene earthquakes and related slip rate along the main segment of the Dead Sea fault south of the Ghab pull-apart basin in western Syria. The 60-70 km long Missyaf segment consists of a single fault branch of the north-south trending left-lateral fault at the plate boundary between Africa and Arabia. The late Quaternary tectonic activity along the fault is characterized by (1) deflected streams with consistent left-lateral displacements of different sizes (50 to 300 m), and (2) ev- idence of large shutter-ridge structures and small pull-apart basins. Microtopographic surveys and trenching across the fault at two sites document the size and timing of paleoseismic events and the related faulting behaviour. Near El Harif village, the fault cut across a Roman aqueduct (younger than 22 AD) and induces 13.6 s0.1 m of left-´ lateral displacement. Nearby trench-excavations and test pits exhibit the fault with the shear zone affecting a succession of young alluvial deposits of a terrace meander. First radiocarbon dating of the faulting events with vertical displacements reveal the occur- rence of a large seismic event prior to 348 BC - 810 BC, a penultimate event between 650 - 1152 AD and the most recent event between 979 - 1255 AD. The two most re- cent events being most likely responsible for the Roman aqueduct total displacement, it implies a coseismic left-lateral movement of 6.8 m per event at this location and a slip rate of about 6 - 7 mm/yr for the last 2000 years. The correlation with the histor- ical seismicity catalogue suggests that the most recent faulting event may correspond to the well documented large earthquake of 1170 AD for which we estimate Mw = 7.3 - 7.5.

  13. Anisotropy of magnetic susceptibility in diamagnetic limestones reveals deflection of the strain field near the Dead Sea Fault, northern Israel

    Science.gov (United States)

    Issachar, R.; Levi, T.; Marco, S.; Weinberger, R.

    2015-08-01

    To exploit the potential of anisotropy of magnetic susceptibility (AMS) as a tool to estimate the strain field around major faults, we measured the AMS of calcite-bearing diamagnetic rocks that crop out next to the Dead Sea Fault (DSF) in northern Israel. Through integrated magnetic and geochemical methods we found that the rocks are almost pure calcite rocks and therefore the magnetic fabric is primarily controlled by preferred crystallographic orientation (PCO) with the minimum principal AMS axes (k3) parallel to calcite c-axes. We applied a separation procedure in several samples with high Fe content in order to calculate the AMS anisotropy parameters and compare them to pure diamagnetic rocks. AARM, thermo-susceptibility curves and IRM were used to characterize the magnetic phases. We found that for Fe content below 500 ppm the AMS is mostly controlled by the diamagnetic phase and showed that differences in the degree of anisotropy P' up to 3% (P' = 1.005 to 1.023) and in anisotropy difference Δk (up to ~ 0.25 × 10- 6 SI) in diamagnetic rocks are related to differences of strain magnitudes. The spatial distribution of the magnetic fabrics indicates ~ N-S maximum shortening parallel to the strike of the Hula Western Border fault (HWBF), one of the main strands of the DSF in northern Israel. The anisotropy parameters suggest that the strain magnitudes increase eastward with the proximity to the HWBF. These results suggest that the strain field near the HWBF is locally deflected as a consequence of the DSF activity. In light of the "fault weakness" model and geological setting of the study area, we suggest that the area accommodates dominant transtension during the Pleistocene. The present study demonstrates the useful application of AMS measurements in "iron-free" limestones as recorders of the strain field near plate boundaries.

  14. Contamination status and accumulation profiles of organotins in sea otters (Enhydra lutris) found dead along the coasts of California, Washington, Alaska (USA), and Kamchatka (Russia).

    Science.gov (United States)

    Murata, Satoko; Takahashi, Shin; Agusa, Tetsuro; Thomas, Nancy J; Kannan, Kurunthachalam; Tanabe, Shinsuke

    2008-04-01

    Organotin compounds (OTs) including mono- to tri-butyltins, -phenyltins, and -octyltins were determined in the liver of adult sea otters (Enhydra lutris) found dead along the coasts of California, Washington, and Alaska in the USA and Kamchatka, Russia. Total concentrations of OTs in sea otters from California ranged from 34 to 4100ng/g on a wet weight basis. The order of concentrations of OTs in sea otters was total butyltins>total octyltins> or = total phenyltins. Elevated concentrations of butyltins (BTs) were found in some otters classified under 'infectious-disease' mortality category. Concentrations of BTs in few of these otters were close to or above the threshold levels for adverse health effects. Total butyltin concentrations decreased significantly in the livers of California sea otters since the 1990s. Based on the concentrations of organotins in sea otters collected from 1992 to 2002, the half-lives of tributyltin and total butyltins in sea otters were estimated to be approximately three years.

  15. Structural Evolution of the India-Arabia Plate Boundary from Miocene to Present-Day (NW Indian Ocean) and Comparison with the Dead Sea Fault (Eastern Mediterranean Sea).

    Science.gov (United States)

    Rodriguez, M.; Huchon, P.; Chamot Rooke, N.; Fournier, M.; Delescluse, M.; Ben Avraham, Z.; Ten Brink, U. S.

    2014-12-01

    Arabia is bounded by the Dead Sea Transform (DST) to the west and by the Owen Fracture Zone (OFZ) to the east. These present-day major strike-slip fault systems activated during the Plio-Pleistocene, which contrasts with the age of inception of strike-slip motion, assumed to begin around 13-18 Ma for the DST and around 20 Ma at the edge of the Owen-Murray Ridge (OMR) for the India-Arabia plate boundary. This discrepancy between the age of the active strike-slip systems and the age of inception of strike-slip motion raises the question of the kinematic driver for the transition between successive generations of strike-slip faults. Using a recent mutibeam and seismic dataset crossing the OFZ and the OMR, we provide a new geodynamic framework for the Miocene to present-day structural evolution of the India-Arabia plate boundary, and highlight some similarities with the structural evolution of the DST. We first document a Late Miocene episode of uplift of the OMR uplift along the Miocene India-Arabia plate boundary. The onset of this uplift is coeval with a plate reorganization event marked by the onset of intra-plate deformation in the Central Indian Ocean. The OFZ emplaced around 3 Ma, with major pull-apart basins opening (20°N Basin, Dalrymple Trough) dated at 2.4 Ma by far-field correlation with ODP Sites. The opening of pull-apart basins is coeval with the last structural reorganization of the Makran accretionnary wedge, marked by the regional M-unconformity, and with a major intensification of the Indian monsoon. A Late Miocene episode of folding is also recognized at the Lebanon ranges prior to the onset of the present-day DST, which occurred in the Late Pliocene-Early Pleistocene. The similarities between the geological history of the India-Arabia plate boundary and the DST in the Late Miocene and the Late Pliocene-Early Pleistocene suggest that both plate boundaries recorded the same kinematic changes. Late Miocene (i.e. Tortonian) deformation is widely

  16. Late Quaternary environmental and human events at En Gedi, reflected by the geology and archaeology of the Moringa Cave (Dead Sea area, Israel)

    Science.gov (United States)

    Lisker, Sorin; Porat, Roi; Davidovich, Uri; Eshel, Hanan; Lauritzen, Stein-Erik; Frumkin, Amos

    2007-09-01

    The Moringa Cave within Pleistocene sediments in the En Gedi area of the Dead Sea Fault Escarpment contains a sequence of various Pleistocene lacustrine deposits associated with higher-than-today lake levels at the Dead Sea basin. In addition it contains Chalcolithic remains and 5th century BC burials attributed to the Persian period, cemented and covered by Late Holocene travertine flowstone. These deposits represent a chain of Late Pleistocene and Holocene interconnected environmental and human events, echoing broader scale regional and global climate events. A major shift between depositional environments is associated with the rapid fall of Lake Lisan level during the latest Pleistocene. This exposed the sediments, providing for cave formation processes sometime between the latest Pleistocene (ca. 15 ka) and the Middle Holocene (ca. 4500 BC), eventually leading to human use of the cave. The Chalcolithic use of the cave can be related to a relatively moist desert environment, probably related to a shift in the location of the northern boundary of the Saharo-Arabian desert belt. The travertine layer was U-Th dated 2.46 ± 0.10 to 2.10 ± 0.04 ka, in agreement with the archaeological finds from the Persian period. Together with the inner consistency of the dating results, this strongly supports the reliability of the radiometric ages. The 2.46-2.10 ka travertine deposition within the presently dry cave suggests a higher recharge of the Judean Desert aquifer, correlative to a rising Dead Sea towards the end of the 1st millennium BC. This suggests a relatively moist local and regional climate facilitating human habitation of the desert.

  17. A MAPK gene from Dead Sea fungus confers stress tolerance to lithium salt and freezing–thawing: Prospects for saline agriculture

    Science.gov (United States)

    Jin, Yan; Weining, Song; Nevo, Eviatar

    2005-01-01

    The Dead Sea is one of the most saline lakes on earth (≈340 g/liter salinity) and is ≈10 times saltier than the oceans. Eurotium herbariorum, a common fungal species, was isolated from its water. EhHOG gene, encoding a mitogen-activated protein kinase (MAPK) that plays an essential role in the osmoregulatory pathway in yeast and many other eukaryotes, was isolated from E. herbariorum. The deduced amino acid sequences of EhHOG indicated high similarity with homologous genes from Aspergillus nidulans, Saccharomyces cerevisiae, and Schizosaccharomyces pombe and contained a TGY motif for phosphorylation by MAPK kinase. When EhHOG was expressed in S. cerevisiae hog1Δ mutant, the growth and aberrant morphology of hog1Δ mutant was restored under high osmotic stress condition. Moreover, intracellular glycerol content in the transformant increased to a much higher level than that in the mutant during salt-stress situations. hog1Δ mutant complemented by EhHOG outperformed the wild type or had higher genetic fitness under high Li+ and freezing–thawing conditions. The present study revealed the putative presence of a high-osmolarity glycerol response (HOG) pathway in E. herbariorum and the significance of EhHOG in osmotic regulation, heat stress, freeze stress, and oxidative stress. The Dead Sea is becoming increasingly more saline while the fungi living in it evolutionarily adapt to its high-saline environment, particularly with the extraordinarily high Li+ concentration. The Dead Sea is potentially an excellent model for studies of evolution under extreme environments and is an important gene pool for future agricultural genetic engineering prospects. PMID:16365289

  18. THE EFFECTS OF POSSIBLE CONTAMINATION ON THE RADIOCARBON DATING OF THE DEAD SEA SCROLLS II: EMPIRICAL METHODS TO REMOVE CASTOR OIL AND SUGGESTIONS FOR REDATING

    OpenAIRE

    Rasmussen, Kaare Lund; van der Plicht, Johannes; Doudna, Gregory; Nielsen, Frederik; Hojrup, Peter; Stenby, Erling Halfdan; Pedersen, Carl Th; Højrup, Peter

    2009-01-01

    While kept at the Rockefeller Museum in East Jerusalem, many Dead Sea Scroll fragments were exposed to castor oil by the original team of editors in the course of cleaning the parchments. Castor oil must be regarded as a serious contaminant in relation to radiocarbon dating. If modern castor oil is present and is not removed prior to dating, the (14)C dates will be skewed artificially towards modern values. In Rasmussen et al. (2001), it was shown that the standard AAA pretreatment procedure ...

  19. Land subsidence, structures and processes at the Dead Sea shoreline as revealed by a near-field photogrammetry survey at Ghor Haditha, Jordan

    Science.gov (United States)

    Al-Halbouni, Djamil; Holohan, Eoghan P.; Walter, Thomas; Alrshdan, Hussam; Sawarieh, Ali; Dahm, Torsten

    2015-04-01

    Rapid recession of the Dead Sea in the last few decades has led to an increasing rate of sinkhole formation around the lake shore. The development of these sinkholes and other land subsidence phenomena poses a major geological hazard to the local population, agriculture and industry. For a better understanding of the underlying physical processes and for determining current and future areas of sinkhole hazard, we conducted field investigations and a first low altitude ("near-field") aerial photogrammetric survey with a Helikite Balloon at Ghor Haditha, Jordan, in October 2014. From the near-field photogrammetry, we generated a high resolution Digital Elevation Model of the surveyed area. This enables a detailed quantification of sinkhole sizes and distribution as well of morphological parameters such as the sinkhole depth/diameter ratio (D). Values of the latter are generally greater in the mechanically stronger alluvial fan sediments (D = 3.0 - 0.4) than in the weaker muds of the former Dead Sea lakebed (D = 0.3 - 0.1). Importantly, the point of emanation of a very recent and sediment-laden stream at c. 10m below the former floor of the Dead Sea can be structurally and morphologically connected to the main sinkhole area. This provides evidence for channelised subterranean groundwater flows beneath this area. From our observations, two processes were identified as key factors for the development of large land subsidence structures and local sinkhole clusters: (1) Subrosion of weak material due to groundwater following preferred flow paths of ancient and current wadi riverbeds and (2) rapid dissolution of soluble material (salt) in this aragonite-rich mud. The heterogeneous geology and alternation of aquifers (alluvial fan sediments) and aquicludes (mud-flats) lead to the formation of complex subsurface flow channels that represent the secondary porosity of the internal structure of karst aquifers. As a consequence of these subterranean channels, local bending and

  20. Calibration of commercial microwave link derived- rainfall and its relevance to flash flood occurrence in the Dead Sea area

    Science.gov (United States)

    Eshel, Adam; Alpert, Pinhas; Raich, Roi; Laronne, Jonathan; Merz, Ralf; Geyer, Stefan; Corsmeier, Ulrich

    2016-04-01

    Flash floods are a common phenomenon in arid and semi-arid areas such as the Dead Sea. These floods are generated due to a combination of short lasting, yet intense rainfall and typical low infiltration rates. The rare flow events in ephemeral rivers have significant importance in the replenishment of groundwater via transmission losses and in sustaining the vivid ecology of drylands. In some cases, flash floods cause severe damage to infrastructure as well as to private property, constituting a threat to human life. The temporal variation of rainfall intensity is the main driver generating the majority of flash floods in the Judean Desert, hence its monitoring is crucial in this area as in other remote arid areas worldwide. Cellular communication towers are profusely located. Commercial Microwave Links (CML) attenuation data obtained by cellular companies can be used for environmental monitoring. Rain is one of the most effective meteorological phenomena to attenuate a CML signal which, unlike radar backscatter, relates to near-surface conditions and is, therefore, suitable for surface hydrology. A 16 km CML crosses the Wadi Ze'elim drainage basin (~250 square kilometers), at the outlet of which the discharge is calculated using the Manning formula. The hydrometric data include accurate longitudinal and cross sectional measurements, water level and importantly mean water surface velocity when present during a flash flood. The latter is first-ever obtained in desert flash floods by portable, radar-based surface velocimetry. Acquisition of water velocity data is essential to avoid assuming a constant roughness coefficient, thereby more accurately calculating water discharge. Calibrating the CML-rain intensity, derived from the International Telecommunication Union (ITU)'s power law, is necessary to correlate the surface hydrologic response to the link. Our calibration approach is as follows: all the Israel Meteorological Service C-band radar cells over the CML

  1. Significant immediate and long-term improvement in quality of life and disease coping in patients with vitiligo after group climatotherapy at the Dead Sea.

    Science.gov (United States)

    Krüger, Christian; Smythe, Jim W; Spencer, Jennifer D; Hasse, Sybille; Panske, Angela; Chiuchiarelli, Giorgia; Schallreuter, Karin U

    2011-03-01

    Quality of life in patients with vitiligo is impaired. This study explored the immediate effect of 20 days of climatotherapy at the Dead Sea on quality of life, coping with the disease, general well-being and individual stress levels in a group of 71 patients with vitiligo and 42 matched controls. The long-term effect was assessed after 12 months in 33/71 patients and 12/42 controls. Study instruments were Dermatology Life Quality Index, Beck Depression Inventory and the Adjustment to Chronic Skin Disorders Questionnaire. Stress measurements were based on cortisol and β-endorphin concentrations in saliva samples. Quality of life was significantly improved at day 20 at the Dead Sea compared with day 1, and this was still significant after 12 months. Moreover, social anxiety/avoidance, anxious-depressive mood and helplessness as measured by the Adjustment to Chronic Skin Disorders Questionnaire were significantly reduced. There was no difference in levels of cortisol and β-endorphin between patients and controls, indicating that stress per se is not a significant contributor in vitiligo. In conclusion, therapy in patient groups offers an effective tool for long-lasting improvement in quality of life and patients' well-being.

  2. Seismic imaging of deep low-velocity zone beneath the Dead Sea basin and transform fault: Implications for strain localization and crustal rigidity

    Science.gov (United States)

    ten Brink, Uri S.; Al-Zoubi, A. S.; Flores, C.H.; Rotstein, Y.; Qabbani, I.; Harder, S.H.; Keller, Gordon R.

    2006-01-01

    New seismic observations from the Dead Sea basin (DSB), a large pull-apart basin along the Dead Sea transform (DST) plate boundary, show a low velocity zone extending to a depth of 18 km under the basin. The lower crust and Moho are not perturbed. These observations are incompatible with the current view of mid-crustal strength at low temperatures and with support of the basin's negative load by a rigid elastic plate. Strain softening in the middle crust is invoked to explain the isostatic compensation and the rapid subsidence of the basin during the Pleistocene. Whether the deformation is influenced by the presence of fluids and by a long history of seismic activity on the DST, and what the exact softening mechanism is, remain open questions. The uplift surrounding the DST also appears to be an upper crustal phenomenon but its relationship to a mid-crustal strength minimum is less clear. The shear deformation associated with the transform plate boundary motion appears, on the other hand, to cut throughout the entire crust. Copyright 2006 by the American Geophysical Union.

  3. An example of aerosol pattern variability over bright surface using high resolution MODIS MAIAC: The eastern and western areas of the Dead Sea and environs

    Science.gov (United States)

    Sever, Lee; Alpert, Pinhas; Lyapustin, Alexei; Wang, Yujie; Chudnovsky, Alexandra

    2017-09-01

    The extreme rate of evaporation of the Dead Sea (DS) has serious implications for the surrounding area, including atmospheric conditions. This study analyzes the aerosol properties over the western and eastern parts of the DS during the year 2013, using MAIAC (Multi-Angle Implementation of Atmospheric Correction) for MODIS, which retrieves aerosol optical depth (AOD) data at a resolution of 1 km. The main goal of the study is to evaluate MAIAC over the study area and determine, for the first time, the prevailing aerosol spatial patterns. First, the MAIAC-derived AOD data was compared with data from three nearby AERONET sites (Nes Ziona - an urban site, and Sede Boker and Masada - two arid sites), and with the conventional Dark Target (DT) and Deep Blue (DB) retrievals for the same days and locations, on a monthly basis throughout 2013. For the urban site, the correlation coefficient (r) for DT/DB products showed better performance than MAIAC (r = 0.80, 0.75, and 0.64 respectively) year-round. However, in the arid zones, MAIAC showed better correspondence to AERONET sites than the conventional retrievals (r = 0.58-0.60 and 0.48-0.50 respectively). We investigated the difference in AOD levels, and its variability, between the Dead Sea coasts on a seasonal basis and calculated monthly/seasonal AOD averages for presenting AOD patterns over arid zones. Thus, we demonstrated that aerosol concentrations show a strong preference for the western coast, particularly during the summer season. This preference, is most likely a result of local anthropogenic emissions combined with the typical seasonal synoptic conditions, the Mediterranean Sea breeze, and the region complex topography. Our results also indicate that a large industrial zone showed higher AOD levels compared to an adjacent reference-site, i.e., 13% during the winter season.

  4. Wind effects on prey availability: How northward migrating waders use brackish and hypersaline lagoons in the Sivash, Ukraine

    NARCIS (Netherlands)

    Verkuil, Yvonne I.; Koolhaas, Anita; Van Der Winden, Jan

    1993-01-01

    Large numbers of waders migrating northward in spring use the Sivash, a large system of shallow, brackish and hypersaline lagoons in the Black Sea and Azov Sea region (Ukraine). The bottoms of these lagoons are often uncovered by the wind. Hence, for waders the time and space available for feeding

  5. Structure and sedimentation of Permo-Triassic and Triassic rocks exposed in small-scale horsts and grabens of pre-Cretaceous age: Dead Sea margin, Jordan

    Science.gov (United States)

    Powell, J. H.; Mohamed, B. Khalil

    1993-08-01

    Small-scale horsts and grabens, formed prior to the deposition of the Lower Cretaceous Kurnub Sandstone, are described for the first time from remote exposures near the eastern shore of the Dead Sea, Jordan. The grabens preserve a sequence of Permo-Triassic and Triassic rocks (Umm Irna and Ma'in Formations), flanked by horsts of Cambrian sandstone (Umm Ishrin Formation). The pre-Cretaceous faults are mostly orientated NNE or ENE, with a maximum vertical displacement of 130 m. Rotation of a joint system, formed during the late Palaeozoic, in the Cambrian sandstone indicates that the horst blocks were rotated anti-clockwise during block faulting. Local and regional stratigraphical evidence suggest that faulting occurred during an extensional tectonic regime in late Jurassic to early Cretaceous times. The horsts and grabens did not affect sedimentation of the basal Kurnub Sandstone and they are preserved without relief below the unconformity, suggesting a period of erosional peneplanation prior to deposition of the fluvial Kurnub Sandstone. The structures probably represent an extension of the Central Naqab-Sinai fault zone which was displaced by sinistral shear along the Dead Sea-Gulf of Aqaba Rift in Tertiary (Neogene) times. Lithofacies sequences in the Umm Irna Formation exposed in the grabens comprise, in ascending sequence, braided to low-sinuosity or meandering fluvial siliciclastic facies, derived from the Arabo-Nubian Shield to the south and south-east. Lithological characteristics, bedforms and pedogenic features suggest a fluctuating, seasonal, semi-arid climate. Transgression of the Tethys Ocean in early Triassic times resulted in deposition of shallow-marine siliciclastics and carbonates (Ma'in Formation) in subtidal to intertidal environments.

  6. Sinkholes, subsidence and subrosion on the eastern shore of the Dead Sea as revealed by a close-range photogrammetric survey

    Science.gov (United States)

    Al-Halbouni, Djamil; Holohan, Eoghan P.; Saberi, Leila; Alrshdan, Hussam; Sawarieh, Ali; Closson, Damien; Walter, Thomas R.; Dahm, Torsten

    2017-05-01

    Ground subsidence and sinkhole collapse are phenomena affecting regions of karst geology worldwide. The rapid development of such phenomena around the Dead Sea in the last four decades poses a major geological hazard to the local population, agriculture and industry. Nonetheless many aspects of this hazard are still incompletely described and understood, especially on the eastern Dead Sea shore. In this work, we present a first low altitude (digital surface model (5 cm px-1) and orthophoto of this area (2.1 km2). We also outline the factors affecting the quality and accuracy of this approach. Our analysis reveals a kilometer-scale sinuous depression bound partly by flexure and partly by non-tectonic faults. The estimated minimum volume loss of this subsided zone is 1.83 ṡ 106 m3 with an average subsidence rate of 0.21 m yr-1 over the last 25 years. Sinkholes in the surveyed area are localized mainly within this depression. The sinkholes are commonly elliptically shaped (mean eccentricity 1.31) and clustered (nearest neighbor ratio 0.69). Their morphologies and orientations depend on the type of sediment they form in: in mud, sinkholes have a low depth to diameter ratio (0.14) and a long-axis azimuth of NNE-NE. In alluvium, sinkholes have a higher ratio (0.4) and are orientated NNW-N. From field work, we identify actively evolving artesian springs and channelized, sediment-laden groundwater flows that appear locally in the main depression. Consequently, subrosion, i.e. subsurface mechanical erosion, is identified as a key physical process, in addition to dissolution, behind the subsidence and sinkhole hazard. Furthermore, satellite image analysis links the development of the sinuous depression and sinkhole formation at Ghor Al-Haditha to preferential groundwater flow paths along ancient and current wadi riverbeds.

  7. Study of the factors affecting the karst volume assessment in the Dead Sea sinkhole problem using microgravity field analysis and 3-D modeling

    Directory of Open Access Journals (Sweden)

    L. V. Eppelbaum

    2008-11-01

    Full Text Available Thousands of sinkholes have appeared in the Dead Sea (DS coastal area in Israel and Jordan during two last decades. The sinkhole development is recently associated with the buried evaporation karst at the depth of 25–50 m from earth's surface caused by the drop of the DS level at the rate of 0.8–1.0 m/yr. Drop in the Dead Sea level has changed hydrogeological conditions in the subsurface and caused surface to collapse. The pre-existing cavern was detected using microgravity mapping in the Nahal Hever South site where seven sinkholes of 1–2 m diameter had been opened. About 5000 gravity stations were observed in the area of 200×200 m2 by the use of Scintrex CG-3M AutoGrav gravimeter. Besides the conventional set of corrections applied in microgravity investigations, a correction for a strong gravity horizontal gradient (DS Transform Zone negative gravity anomaly influence was inserted. As a result, residual gravity anomaly of –(0.08÷0.14 mGal was revealed. The gravity field analysis was supported by resistivity measurements. We applied the Emigma 7.8 gravity software to create the 3-D physical-geological models of the sinkholes development area. The modeling was confirmed by application of the GSFC program developed especially for 3-D combined gravity-magnetic modeling in complicated environments. Computed numerous gravity models verified an effective applicability of the microgravity technology for detection of karst cavities and estimation of their physical-geological parameters. A volume of the karst was approximately estimated as 35 000 m3. The visual analysis of large sinkhole clusters have been forming at the microgravity anomaly site, confirmed the results of microgravity mapping and 3-D modeling.

  8. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Martins

    2012-09-01

    Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  9. Hydroclimatic variability in the Levant during the early last glacial (∼ 117-75 ka) derived from micro-facies analyses of deep Dead Sea sediments

    Science.gov (United States)

    Neugebauer, I.; Schwab, M. J.; Waldmann, N. D.; Tjallingii, R.; Frank, U.; Hadzhiivanova, E.; Naumann, R.; Taha, N.; Agnon, A.; Enzel, Y.; Brauer, A.

    2015-08-01

    The new sediment record from the deep Dead Sea basin (ICDP core 5017-1) provides a unique archive for hydroclimatic variability in the Levant. Here, we present high-resolution sediment facies analysis and elemental composition by μXRF scanning of core 5017-1 to trace lake levels and responses of the regional hydroclimatology during the time interval from ca 117-75 ka, i.e. the transition between the last interglacial and the onset of the last glaciation. We distinguished six major micro-facies types and interpreted these and their alterations in the core in terms of relative lake level changes. The two end-member facies for highest and lowest lake levels are (a) up to several meters thick, greenish sediments of alternating aragonite and detrital marl laminae (aad) and (b) thick halite facies, respectively. Intermediate lake levels are characterised by detrital marls with varying amounts of aragonite, gypsum or halite, reflecting lower-amplitude, shorter-term variability. Two intervals of pronounced lake level drops occurred at ∼110-108 ± 5 and ∼93-87 ± 7 ka. They likely coincide with stadial conditions in the central Mediterranean (Melisey I and II pollen zones in Monticchio) and low global sea levels during MIS 5d and 5b. However, our data do not support the current hypothesis of an almost complete desiccation of the Dead Sea during the earlier of these lake level low stands based on a recovered gravel layer. Based on new petrographic analyses, we propose that, although it was a low stand, this well-sorted gravel layer may be a vestige of a thick turbidite that has been washed out during drilling rather than an in-situ beach deposit. Two intervals of higher lake stands at ∼108-93 ± 6 and ∼87-75 ± 7 ka correspond to interstadial conditions in the central Mediterranean, i.e. pollen zones St. Germain I and II in Monticchio, and GI 24 + 23 and 21 in Greenland, as well as to sapropels S4 and S3 in the Mediterranean Sea. These apparent correlations suggest

  10. Hydroclimatic variability in the Levant during the early last glacial (˜ 117-75 ka) derived from micro-facies analyses of deep Dead Sea sediments

    Science.gov (United States)

    Neugebauer, I.; Schwab, M. J.; Waldmann, N. D.; Tjallingii, R.; Frank, U.; Hadzhiivanova, E.; Naumann, R.; Taha, N.; Agnon, A.; Enzel, Y.; Brauer, A.

    2016-01-01

    The new sediment record from the deep Dead Sea basin (ICDP core 5017-1) provides a unique archive for hydroclimatic variability in the Levant. Here, we present high-resolution sediment facies analysis and elemental composition by micro-X-ray fluorescence (µXRF) scanning of core 5017-1 to trace lake levels and responses of the regional hydroclimatology during the time interval from ca. 117 to 75 ka, i.e. the transition between the last interglacial and the onset of the last glaciation. We distinguished six major micro-facies types and interpreted these and their alterations in the core in terms of relative lake level changes. The two end-member facies for highest and lowest lake levels are (a) up to several metres thick, greenish sediments of alternating aragonite and detrital marl laminae (aad) and (b) thick halite facies, respectively. Intermediate lake levels are characterised by detrital marls with varying amounts of aragonite, gypsum or halite, reflecting lower-amplitude, shorter-term variability. Two intervals of pronounced lake level drops occurred at ˜ 110-108 ± 5 and ˜ 93-87 ± 7 ka. They likely coincide with stadial conditions in the central Mediterranean (Melisey I and II pollen zones in Monticchio) and low global sea levels during Marine Isotope Stage (MIS) 5d and 5b. However, our data do not support the current hypothesis of an almost complete desiccation of the Dead Sea during the earlier of these lake level low stands based on a recovered gravel layer. Based on new petrographic analyses, we propose that, although it was a low stand, this well-sorted gravel layer may be a vestige of a thick turbidite that has been washed out during drilling rather than an in situ beach deposit. Two intervals of higher lake stands at ˜ 108-93 ± 6 and ˜ 87-75 ± 7 ka correspond to interstadial conditions in the central Mediterranean, i.e. pollen zones St. Germain I and II in Monticchio, and Greenland interstadials (GI) 24+23 and 21 in Greenland, as well as to

  11. Fracture patterns of the drainage basin of Wadi Dahab in relation to tectonic-landscape evolution of the Gulf of Aqaba - Dead Sea transform fault

    Science.gov (United States)

    Shalaby, Ahmed

    2017-10-01

    Crustal rifting of the Arabian-Nubian Shield and formation of the Afro-Arabian rifts since the Miocene resulted in uplifting and subsequent terrain evolution of Sinai landscapes; including drainage systems and fault scarps. Geomorphic evolution of these landscapes in relation to tectonic evolution of the Afro-Arabian rifts is the prime target of this study. The fracture patterns and landscape evolution of the Wadi Dahab drainage basin (WDDB), in which its landscape is modeled by the tectonic evolution of the Gulf of Aqaba-Dead Sea transform fault, are investigated as a case study of landscape modifications of tectonically-controlled drainage systems. The early developed drainage system of the WDDB was achieved when the Sinai terrain subaerially emerged in post Eocene and initiation of the Afro-Arabian rifts in the Oligo-Miocene. Conjugate shear fractures, parallel to trends of the Afro-Arabian rifts, are synthesized with tensional fracture arrays to adapt some of inland basins, which represent the early destination of the Sinai drainage systems as paleolakes trapping alluvial sediments. Once the Gulf of Aqaba rift basin attains its deeps through sinistral movements on the Gulf of Aqaba-Dead Sea transform fault in the Pleistocene and the consequent rise of the Southern Sinai mountainous peaks, relief potential energy is significantly maintained through time so that it forced the Pleistocene runoffs to flow via drainage systems externally into the Gulf of Aqaba. Hence the older alluvial sediments are (1) carved within the paleolakes by a new generation of drainage systems; followed up through an erosional surface by sandy- to silty-based younger alluvium; and (2) brought on footslopes of fault scarps reviving the early developed scarps and inselbergs. These features argue for crustal uplifting of Sinai landscapes syn-rifting of the Gulf of Aqaba rift basin. Oblique orientation of the Red Sea-Gulf of Suez rift relative to the WNW-trending Precambrian Najd faults; and

  12. The 11th Century Collapse of Aqaba on the North Coast of the Gulf of Aqaba, Dead Sea Fault System, Jordan

    Science.gov (United States)

    Niemi, Tina; Allison, Alivia; Rucker, John

    2010-05-01

    The city of Aqaba is situated at the northern end of the Gulf of Aqaba along the southern part of the Dead Sea Transform Fault. Based both on the historical accounts and archaeological excavations, it is clear that earthquakes have played a significant role in the history of the region. The early Islamic city of Ayla was probably founded around 650 A.D., suffered some damage as a result of the 748 A.D. earthquake, and saw extensive reconstruction around the beginning of the Abbasid period (Whitcomb, 1994). Among other evidence of earthquake destruction at the Islamic city of Ayla is the leaning city Sea wall. Stratified pottery collections from our February 2009 excavation of the buttress of the city wall of Ayla strongly suggest a date for revetment construction in the early 11th Century. Based on the fact that the most recent pottery from sealed loci inside the buttress wall is late Abbasid - Fatimid and the absence of handmade pottery often found in the abandonment phases, the buttress was likely constructed after liquefaction damage from the 1033 earthquake. Damage from distant source earthquakes (748 and 1033) in the ancient city was repaired in antiquity. The destruction and loss of life (accounts claim that all but 12 residents who had been out fishing were killed) caused by the 1068 earthquake may account for the relative ease with which Baldwin I of Jerusalem took over when he arrived with a small retinue in 1116 A.D. Paleoseismic trenches in the modern city of Aqaba indicate that at least two earthquakes have occurred after deposits dated to 1045-1278 A.D. A preliminary analysis of the stratigraphy in new trenches in the Taba sabkha north of Aqaba shows at least three separate faulting events, with the most recent event located at a depth of 70 cm below the ground surface. This finding supports the initial ground penetrating radar survey conducted at the southern end of the Taba sabkha by Abueladas (2005). These data document a long period of quiescence

  13. Living and dead foraminiferal assemblages from an active submarine canyon and surrounding sectors: the Gioia Canyon system (Tyrrhenian Sea, Southern Italy)

    Science.gov (United States)

    Letizia, Di Bella; Martina, Pierdomenico; Roberta, Porretta; Chiocci, Francesco Latino; Eleonora, Martorelli

    2017-05-01

    Living (rose Bengal stained) and dead benthic foraminiferal assemblages were studied from 23 stations located between 60 and 670 m depth along the Gioia Canyon and the adjacent continental shelf and slope (Southern Tyrrhenian Sea). The aim of this study is to investigate the relationships among sedimentary processes, hydrological patterns and benthic foraminiferal distribution, in a highly dynamic environment. High sedimentation rates on the shelf and occasional turbidity flows along the canyon, lead to unstable environmental conditions at the seafloor that reflect on the microbenthic community influencing faunal density, diversity, species composition and distribution inside the sediment. The foraminiferal distribution seems to be controlled by sedimentary processes, nutrient supply and organic matter recycling, which in turn are strongly controlled by the seasonal variability of riverine inputs and current dynamics in the Gulf of Gioia. From the inner shelf to the upper continental slope (550 m depth), the living foraminiferal assemblage is dominated by agglutinated taxa, likely favored by the high terrigenous supply. Frequent eutrophic taxa (Valvulineria bradyana and Nonionella turgida) tolerant high turbidity (Leptohalysis scottii,) and low oxygen (Bolivina spp. and Bulimina spp.) are recorded on the edge of the inner shelf, where channeling, deposition of coastal deposits and occasional sediment gravity flows occur. In the outer sector of the shelf a turnover of species is observed; L. scottii replaced by the opportunistic species Reophax scorpiurus, and taxa indicative of high energy conditions (Cassidulina spp.) become dominant in association with mesotrophic species like Globocassidulina subglobosa. Along the continental slope, lower sedimentation rates and more stable environmental conditions support richer and more diversified foraminiferal assemblage. The abundance of Bulimina marginata indicates eutrophic conditions at the shallower station (300 m depth

  14. High-resolution InSAR constraints on flood-related subsidence and evaporite dissolution along the Dead Sea shores: Interplay between hydrology and rheology

    Science.gov (United States)

    Shviro, Maayan; Haviv, Itai; Baer, Gidon

    2017-09-01

    Sinkhole generation and land subsidence are commonly attributed to dissolution of subsurface layers by under-saturated groundwater and formation of cavities. Along the Dead Sea (DS) shorelines, this process also involves seasonal flash floods that are drained into the subsurface by existing and newly formed sinkholes. We quantify the contribution of flash-floods to salt dissolution and land subsidence using high-resolution interferometric synthetic aperture radar (InSAR). Subsidence rates during a 3-year period (2012-2015) were calculated from 57 COSMO SkyMed X-band interferograms bracketing major flood events and intra-flood periods in 21 sinkhole sites. The sites are located within channels and alluvial fans along the western shores of the Dead Sea, Israel. The observed subsidence reaches maximum rates of 2.5 mm/day, accumulating in specific sites to 500 mm/year. In most of the sinkhole sites a gradual increase in the annual subsidence rate is observed during the 3-year study period. Three different modes of response to floods were observed: (1) sites where floodwater is not directly channeled into sinkholes do not respond to floods; (2) sites adjacent to active channels with sinkholes are unaffected by specific floods but their subsidence rates increase gradually from early winter to mid-summer, and decay gradually until the following winter; and (3) sites in active channels with sinkholes are characterized by an abrupt increase in subsidence rates immediately after each flood (by a factor of up to 20) and by a subsequent quasi-exponential subsidence decay over periods of several months. In these latter sites, subsidence rates after each flood are temporally correlated with alternating groundwater levels in adjacent boreholes. The rapid rise in groundwater head following floods increases the hydraulic gradient of the under-saturated groundwater and hence also the groundwater discharge and the dissolution rate of the subsurface salt layer. A subsequent quasi

  15. Dead Man or Dead Hand?

    DEFF Research Database (Denmark)

    Ringe, Wolf-Georg

    and potential takeover bids. Recent Delaware case-law suggests that the most extreme, ‘dead hand’ version of such clauses might violate directors’ fiduciary duties. This short article develops some initial thoughts on the phenomenon and evaluates how the new poison pills would be handled under European takeover...

  16. Convective rainfall in a dry climate: relations with synoptic systems and flash-flood generation in the Dead Sea region

    Science.gov (United States)

    Belachsen, Idit; Marra, Francesco; Peleg, Nadav; Morin, Efrat

    2017-10-01

    Spatiotemporal patterns of rainfall are important characteristics that influence runoff generation and flash-flood magnitude and require high-resolution measurements to be adequately represented. This need is further emphasized in arid climates, where rainfall is scarce and highly variable. In this study, 24 years of corrected and gauge-adjusted radar rainfall estimates are used to (i) identify the spatial structure and dynamics of convective rain cells in a dry climate region in the Eastern Mediterranean, (ii) to determine their climatology, and (iii) to understand their relation with the governing synoptic systems and with flash-flood generation. Rain cells are extracted using a segmentation method and a tracking algorithm, and are clustered into three synoptic patterns according to atmospheric variables from the ERA-Interim reanalysis. On average, the cells are about 90 km2 in size, move 13 m s-1 from west to east, and live for 18 min. The Cyprus low accounts for 30 % of the events, the low to the east of the study region for 44 %, and the Active Red Sea Trough for 26 %. The Active Red Sea Trough produces shorter rain events composed of rain cells with higher rain intensities, longer lifetime, smaller area, and lower velocities. The area of rain cells is positively correlated with topographic height. The number of cells is negatively correlated with the distance from the shoreline. Rain-cell intensity is negatively correlated with mean annual precipitation. Flash-flood-related events are dominated by rain cells of large size, low velocity, and long lifetime that move downstream with the main axis of the catchments. These results can be further used for stochastic simulations of convective rain storms and serve as input for hydrological models and for flash-flood nowcasting systems.

  17. Variable slip-rate and slip-per-event on a plate boundary fault: The Dead Sea fault in northern Israel

    Science.gov (United States)

    Wechsler, Neta; Rockwell, Thomas K.; Klinger, Yann

    2018-01-01

    We resolved displacement on buried stream channels that record the past 3400 years of slip history for the Jordan Gorge (JGF) section of the Dead Sea fault in Israel. Based on three-dimensional (3D) trenching, slip in the past millennium amounts to only 2.7 m, similar to that determined in previous studies, whereas the previous millennium experienced two to three times this amount of displacement with nearly 8 m of cumulative slip, indicating substantial short term variations in slip rate. The slip rate averaged over the past 3400 years, as determined from 3D trenching, is 4.1 mm/yr, which agrees well with geodetic estimates of strain accumulation, as well as with longer-term geologic slip rate estimates. Our results indicate that: 1) the past 1200 years appear to significantly lack slip, which may portend a significant increase in future seismic activity; 2) short-term slip rates for the past two millennia have varied by more than a factor of two and suggest that past behavior is best characterized by clustering of earthquakes. From these observations, the earthquake behavior of the Jordan Gorge fault best fits is a ;weak segment model; where the relatively short fault section (20 km), bounded by releasing steps, fails on its own in moderate earthquakes, or ruptures with adjacent segments.

  18. Fire and brimstone: the microbially mediated formation of elemental sulfur nodules from an isotope and major element study in the paleo-Dead Sea.

    Directory of Open Access Journals (Sweden)

    Tom Bishop

    Full Text Available We present coupled sulfur and oxygen isotope data from sulfur nodules and surrounding gypsum, as well as iron and manganese concentration data, from the Lisan Formation near the Dead Sea (Israel. The sulfur isotope composition in the nodules ranges between -9 and -11‰, 27 to 29‰ lighter than the surrounding gypsum, while the oxygen isotope composition of the gypsum is constant around 24‰. The constant sulfur isotope composition of the nodule is consistent with formation in an 'open system'. Iron concentrations in the gypsum increase toward the nodule, while manganese concentrations decrease, suggesting a redox boundary at the nodule-gypsum interface during aqueous phase diagenesis. We propose that sulfur nodules in the Lisan Formation are generated through bacterial sulfate reduction, which terminates at elemental sulfur. We speculate that the sulfate-saturated pore fluids, coupled with the low availability of an electron donor, terminates the trithionate pathway before the final two-electron reduction, producing thionites, which then disproportionate to form abundant elemental sulfur.

  19. Climate change and dead zones.

    Science.gov (United States)

    Altieri, Andrew H; Gedan, Keryn B

    2015-04-01

    Estuaries and coastal seas provide valuable ecosystem services but are particularly vulnerable to the co-occurring threats of climate change and oxygen-depleted dead zones. We analyzed the severity of climate change predicted for existing dead zones, and found that 94% of dead zones are in regions that will experience at least a 2 °C temperature increase by the end of the century. We then reviewed how climate change will exacerbate hypoxic conditions through oceanographic, ecological, and physiological processes. We found evidence that suggests numerous climate variables including temperature, ocean acidification, sea-level rise, precipitation, wind, and storm patterns will affect dead zones, and that each of those factors has the potential to act through multiple pathways on both oxygen availability and ecological responses to hypoxia. Given the variety and strength of the mechanisms by which climate change exacerbates hypoxia, and the rates at which climate is changing, we posit that climate change variables are contributing to the dead zone epidemic by acting synergistically with one another and with recognized anthropogenic triggers of hypoxia including eutrophication. This suggests that a multidisciplinary, integrated approach that considers the full range of climate variables is needed to track and potentially reverse the spread of dead zones. © 2014 John Wiley & Sons Ltd.

  20. Spatio-temporal variations of zooplankton community in the hypersaline lagoon of Bardawil, North Sinai, Egypt

    OpenAIRE

    Mageed, A.A.A.

    2006-01-01

    Bardawil Lagoon is a shallow oligotrophic hypersaline lake, located at the northern periphery of Sinai peninsula-Egypt, connected to SE Mediterranean Sea through two main openings known as Boughazes. Distribution of zooplankton in Bardawil Lagoon during 2004 was studied, not only in space and time but also with reference to species assemblages and environmental factors. Copepoda, Protozoa, and Mollusca were dominating the lagoon zooplankton community during the period of study with 58 identif...

  1. 3D structure of a complex of transform basins from gravity data, a case study from the central Dead Sea fault

    Science.gov (United States)

    Rosenthal, Michal; Schattner, Uri; Ben-Avraham, Zvi

    2017-04-01

    The Kinneret-Bet She'an (KBS) basin complex comprises the Sea of Galilee, Kinarot, and Bet She'an sub-basins. The complex developed at the intersection between two major tectonic boundaries: the Oligo-Miocene Azraq-Sirhan failed rift, that later developed into the southern Galilee basins and Carmel-Gilboa fault system; and the Dead Sea fault (DSF) plate boundary that developed since the Miocene. Despite numerous studies, KBS still remains one of the enigmatic basin complexes. Its structure, stratigraphy and development are vaguely understood - both inside the basin and in correlation with its surroundings. Our study presents a new and comprehensive 3D model for the structure of KBS complex. It is based on all available gravity measurements, adopted from the national gravity database, and new gravity measurements, collected in cooperation with the Geological Survey of Israel and funded by the Ministry of National Infrastructure, Energy and Water Resources. The gravity data were integrated with constraints from boreholes, surface geology, seismic surveys, potential field studies and teleseismic tomography. The dense distribution of gravity data [1] provides suitable coverage for modeling the deep structure in three dimensions. The model details the spatial distribution, depth, thickness and density of the following regional units within the KBS complex and across its surroundings: upper crust, pre-Senonian sediments, Senonian and Cenozoic sediments, Miocene volcanics, Pliocene and Quaternary volcanics. Additional local units include salt, gabbro and pyroclasts. Results indicate that the KBS complex comprises two sub-basins separated by a structural saddle: Kinneret-Kinarot ( 6-7 km deep, 45 km long) and Bet She'an ( 4 km deep, 10 km long) sub-basin. A 500 m thick layer of Miocene volcanics appears across the Bet She'an sub-basin, yet missing from the Kinneret-Kinarot sub-basin. Between the basins Zemah-1 borehole penetrated a salt unit. The model indicates that this

  2. Dead Sea salt irrigations vs saline irrigations with nasal steroids for symptomatic treatment of chronic rhinosinusitis: a randomized, prospective double-blind study.

    Science.gov (United States)

    Friedman, Michael; Hamilton, Craig; Samuelson, Christian G; Maley, Alexander; Wilson, Meghan N; Venkatesan, T K; Joseph, Ninos J

    2012-01-01

    Intranasal steroids are 1 of the most frequently prescribed medications for the treatment of chronic rhinosinusitis (CRS), and saline irrigations are commonly used as an adjunct to medical therapy. We aimed to compare the efficacy of Dead Sea salt (DSS) irrigations and DSS nasal spray vs saline irrigations and topical nasal steroid spray in the treatment of symptoms of CRS. A total of 145 symptomatic adult patients without acute infection were initially enrolled and 114 completed the study. Patients completed a Sino-Nasal Outcomes Test 20 (SNOT-20) survey (primary outcome metric) and underwent endonasal examination, acoustic rhinometry, and smell testing (secondary outcome metrics). Patients were randomized to 2 groups. The experimental group (n = 59) self-administered hypertonic DSS spray and DSS irrigation; the control group (n = 55) self-administered fluticasone spray and hypertonic saline irrigation and spray. Patients and staff were blinded to group assignment. Outcomes were reassessed at 4 weeks. The 2 groups were homogeneous with respect to pretreatment primary and secondary outcome metrics. Dropout rates were 30% in the DSS group and 36.6% in the control group. Both groups showed significant improvement in mean SNOT-20 scores following treatment; however, the degree of improvement was not significantly different between groups (p = 0.082). There were no significant changes in secondary outcome metrics between the 2 groups. For patients with CRS, treatment with DSS irrigations and sprays appears as effective for symptom reduction as a combination of hypertonic saline irrigations and sprays and a topical steroid spray. Copyright © 2011 American Rhinologic Society-American Academy of Otolaryngic Allergy, LLC.

  3. Fleeing to Fault Zones: Incorporating Syrian Refugees into Earthquake Risk Analysis along the East Anatolian and Dead Sea Rift Fault Zones

    Science.gov (United States)

    Wilson, B.; Paradise, T. R.

    2016-12-01

    The influx of millions of Syrian refugees into Turkey has rapidly changed the population distribution along the Dead Sea Rift and East Anatolian Fault zones. In contrast to other countries in the Middle East where refugees are accommodated in camp environments, the majority of displaced individuals in Turkey are integrated into cities, towns, and villages—placing stress on urban settings and increasing potential exposure to strong shaking. Yet, displaced populations are not traditionally captured in data sources used in earthquake risk analysis or loss estimations. Accordingly, we present a district-level analysis assessing the spatial overlap of earthquake hazards and refugee locations in southeastern Turkey to determine how migration patterns are altering seismic risk in the region. Using migration estimates from the U.S. Humanitarian Information Unit, we create three district-level population scenarios that combine official population statistics, refugee camp populations, and low, median, and high bounds for integrated refugee populations. We perform probabilistic seismic hazard analysis alongside these population scenarios to map spatial variations in seismic risk between 2011 and late 2015. Our results show a significant relative southward increase of seismic risk for this period due to refugee migration. Additionally, we calculate earthquake fatalities for simulated earthquakes using a semi-empirical loss estimation technique to determine degree of under-estimation resulting from forgoing migration data in loss modeling. We find that including refugee populations increased casualties by 11-12% using median population estimates, and upwards of 20% using high population estimates. These results communicate the ongoing importance of placing environmental hazards in their appropriate regional and temporal context which unites physical, political, cultural, and socio-economic landscapes. Keywords: Earthquakes, Hazards, Loss-Estimation, Syrian Crisis, Migration

  4. Heterotrophic Protists in Hypersaline Microbial Mats and Deep Hypersaline Basin Water Columns

    Directory of Open Access Journals (Sweden)

    Joan M. Bernhard

    2013-05-01

    Full Text Available Although hypersaline environments pose challenges to life because of the low water content (water activity, many such habitats appear to support eukaryotic microbes. This contribution presents brief reviews of our current knowledge on eukaryotes of water-column haloclines and brines from Deep Hypersaline Anoxic Basins (DHABs of the Eastern Mediterranean, as well as shallow-water hypersaline microbial mats in solar salterns of Guerrero Negro, Mexico and benthic microbialite communities from Hamelin Pool, Shark Bay, Western Australia. New data on eukaryotic diversity from Shark Bay microbialites indicates eukaryotes are more diverse than previously reported. Although this comparison shows that eukaryotic communities in hypersaline habitats with varying physicochemical characteristics are unique, several groups are commonly found, including diverse alveolates, strameonopiles, and fungi, as well as radiolaria. Many eukaryote sequences (SSU in both regions also have no close homologues in public databases, suggesting that these environments host unique microbial eukaryote assemblages with the potential to enhance our understanding of the capacity of eukaryotes to adapt to hypersaline conditions.

  5. Improved marine reservoir age estimation and palaeoclimate synchronisation of the early Holocene Levantine/NW-Arabian region based on identification of the S1 tephra in Dead Sea and Tayma palaeolake sediments

    Science.gov (United States)

    Neugebauer, Ina; Wulf, Sabine; Schwab, Markus J.; Serb, Johanna; Plessen, Birgit; Appelt, Oona; Brauer, Achim

    2017-04-01

    Due to a lack of tephras identified in marine and terrestrial palaeoclimate records from the Levantine-Arabian area, this region is still not sufficiently connected to the eastern Mediterranean tephrostratigraphical lattice. Here we report on the first finding of cryptotephra in the Holocene lacustrine sediment records of the Dead Sea and the Tayma palaeolake (NW Arabian Peninsula). The major elemental chemistry of the rhyolitic glass shards proves this tephra identical to the distal 'S1 tephra' identified in the Yammoûneh palaeolake, Lebanon (Develle et al, 2009), in a marine sediment record from the SE Levantine basin (Hamann et al., 2010) and in the Sodmein Cave archaeological site in Egypt (Barton et al., 2015). The 'S1 tephra', most likely corresponding to the early Holocene 'Dikkartın' dome eruption of the Erciyes Daǧ volcano in central Anatolia, Turkey, has been dated in the marine record at 8830 ± 140 cal yr BP. We present new age estimates of the 'S1 tephra' based on radiocarbon dating of terrestrial plant remains (Migowski et al., 2004) and pollen concentrates (Dinies et al., 2015), which reveal modelled ages of 8939 ± 83 cal yr BP in the Dead Sea sediments and 9041 ± 254 cal yr BP in Tayma. This allows the estimation of an early Holocene marine reservoir age of ca. 320 years in the SE Levantine Sea. The timing of the volcanic eruption during the early Holocene humid period, which led to the formation of sapropel S1 in the Mediterranean Sea, and the identification of the 'S1 tephra' more than 1200 km to the south are crucial for the synchronisation of marine and terrestrial palaeoclimate records in the eastern Mediterranean region. References: Barton et al., 2015. The role of cryptotephra in refining the chronology of Late Pleistocene human evolution and cultural change in North Africa. Quaternary Sci. Rev. 118, 151-169. Develle et al., 2009. Early Holocene volcanic ash fallout in the Yammoûneh lacustrine basin (Lebanon): Tephrochronological

  6. Pressure retarded osmosis from hypersaline sources - A review

    DEFF Research Database (Denmark)

    Bajraktari, Niada; Hélix-Nielsen, Claus; Madsen, Henrik T.

    2017-01-01

    for commercialization. The scope of this paper is to review the existing knowledge on the use of hypersaline waters in the salinity gradient process, pressure retarded osmosis. Although only few papers have had the specific aim of investigating hypersaline waters, concentrated solutions have been used in many papers...

  7. Love the dead, fear the dead

    DEFF Research Database (Denmark)

    Seebach, Sophie Hooge

    2017-01-01

    The dead are everywhere in the landscape in Acholi, northern Uganda. In the homes, the dead are present through their gravesites, situated next to houses and huts, and as spiritual presences in their family’s daily lives. In the bush, the dead are present as a constant potentiality, in the form...... of abandoned bones and rootless spirits; the remnants of years of civil war. This chapter deals with these landscapes of death, and explores how consolation is found through tying the dead to the land: to the home. It also explores the constant peril that this way of life poses, as living in such close...

  8. Discovery of anaerobic lithoheterotrophic haloarchaea, ubiquitous in hypersaline habitats

    NARCIS (Netherlands)

    Sorokin, D.Y.; Messina, E.; Smedile, F; Roman, P.; Sinninghe Damsté, J.S.; Ciordia, S.; Mena, M.C.; Ferrer, M.; Golyshin, P.N.; Kublanov, I.V.; Samarov, N.I.; Toshchakov, S.V.; La Cono, V.; Yakimov, M.M.

    2017-01-01

    Hypersaline anoxic habitats harbour numerous novel uncultured archaea whose metabolic and ecological roles remain to be elucidated. Until recently, it was believed that energy generation via dissimilatory reduction of sulfur compounds is not functional at salt saturation conditions. Recent discovery

  9. Microbial characterization of a subzero, hypersaline methane seep in the Canadian High Arctic.

    Science.gov (United States)

    Niederberger, Thomas D; Perreault, Nancy N; Tille, Stephanie; Lollar, Barbara Sherwood; Lacrampe-Couloume, Georges; Andersen, Dale; Greer, Charles W; Pollard, Wayne; Whyte, Lyle G

    2010-10-01

    We report the first microbiological characterization of a terrestrial methane seep in a cryo-environment in the form of an Arctic hypersaline (∼24% salinity), subzero (-5 °C), perennial spring, arising through thick permafrost in an area with an average annual air temperature of -15 °C. Bacterial and archaeal 16S rRNA gene clone libraries indicated a relatively low diversity of phylotypes within the spring sediment (Shannon index values of 1.65 and 1.39, respectively). Bacterial phylotypes were related to microorganisms such as Loktanella, Gillisia, Halomonas and Marinobacter spp. previously recovered from cold, saline habitats. A proportion of the bacterial phylotypes were cultured, including Marinobacter and Halomonas, with all isolates capable of growth at the in situ temperature (-5 °C). Archaeal phylotypes were related to signatures from hypersaline deep-sea methane-seep sediments and were dominated by the anaerobic methane group 1a (ANME-1a) clade of anaerobic methane oxidizing archaea. CARD-FISH analyses indicated that cells within the spring sediment consisted of ∼84.0% bacterial and 3.8% archaeal cells with ANME-1 cells accounting for most of the archaeal cells. The major gas discharging from the spring was methane (∼50%) with the low CH(4)/C(2+) ratio and hydrogen and carbon isotope signatures consistent with a thermogenic origin of the methane. Overall, this hypersaline, subzero environment supports a viable microbial community capable of activity at in situ temperature and where methane may behave as an energy and carbon source for sustaining anaerobic oxidation of methane-based microbial metabolism. This site also provides a model of how a methane seep can form in a cryo-environment as well as a mechanism for the hypothesized Martian methane plumes.

  10. Day of the Dead

    Science.gov (United States)

    Dann, Tammy; Murphy, Amy

    2012-01-01

    Foreign Language in Elementary School (FLES) teachers in the West Des Moines schools incorporate the Day of the Dead into the fourth grade curriculum each year. The teachers discuss the Day of the Dead celebration at the Art Center, and many ask for volunteers from fourth grade to participate in the event. Student presentations include a wide…

  11. Investigating Aquatic Dead Zones

    Science.gov (United States)

    Testa, Jeremy; Gurbisz, Cassie; Murray, Laura; Gray, William; Bosch, Jennifer; Burrell, Chris; Kemp, Michael

    2010-01-01

    This article features two engaging high school activities that include current scientific information, data, and authentic case studies. The activities address the physical, biological, and chemical processes that are associated with oxygen-depleted areas, or "dead zones," in aquatic systems. Students can explore these dead zones through both…

  12. On the nature of rainfall in dry climate: Space-time patterns of convective rain cells over the Dead Sea region and their relations with synoptic state and flash flood generation

    Science.gov (United States)

    Belachsen, Idit; Marra, Francesco; Peleg, Nadav; Morin, Efrat

    2017-04-01

    Space-time patterns of rainfall are important climatic characteristics that influence runoff generation and flash flood magnitude. Their derivation requires high-resolution measurements to adequately represent the rainfall distribution, and is best provided by remote sensing tools. This need is further emphasized in dry climate regions, where rainfall is scarce and, often, local and highly variable. Our research is focused on understanding the nature of rainfall events in the dry Dead Sea region (Eastern Mediterranean) by identifying and characterizing the spatial structure and the dynamics of convective storm cores (known as rain cells). To do so, we take advantage of 25 years of corrected and gauge-adjusted weather radar data. A statistical analysis of convective rain-cells spatial and temporal characteristics was performed with respect to synoptic pattern, geographical location, and flash flood generation. Rain cells were extracted from radar data using a cell segmentation method and a tracking algorithm and were divided into rain events. A total of 10,500 rain cells, 2650 cell tracks and 424 rain events were elicited. Rain cell properties, such as mean areal and maximal rain intensity, area, life span, direction and speed, were derived. Rain events were clustered, according to several ERA-Interim atmospheric parameters, and associated with three main synoptic patterns: Cyprus Low, Low to the East of the study region and Active Red Sea Trough. The first two originate from the Mediterranean Sea, while the third is an extension of the African monsoon. On average, the convective rain cells in the region are 90 km2 in size, moving from West to East in 13 ms-1 and living 18 minutes. Several significant differences between rain cells of the various synoptic types were observed. In particular, Active Red Sea Trough rain cells are characterized by higher rain intensities and lower speeds, suggesting a higher flooding potential for small catchments. The north

  13. Microbial diversity of hypersaline environments: a metagenomic approach.

    Science.gov (United States)

    Ventosa, Antonio; de la Haba, Rafael R; Sánchez-Porro, Cristina; Papke, R Thane

    2015-06-01

    Recent studies based on metagenomics and other molecular techniques have permitted a detailed knowledge of the microbial diversity and metabolic activities of microorganisms in hypersaline environments. The current accepted model of community structure in hypersaline environments is that the square archaeon Haloquadratum waslbyi, the bacteroidete Salinibacter ruber and nanohaloarchaea are predominant members at higher salt concentrations, while more diverse archaeal and bacterial taxa are observed in habitats with intermediate salinities. Additionally, metagenomic studies may provide insight into the isolation and characterization of the principal microbes in these habitats, such as the recently described gammaproteobacterium Spiribacter salinus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. An Updated View of the Microbial Diversity in Deep Hypersaline Anoxic Basins

    KAUST Repository

    Mapelli, Francesca

    2017-03-02

    Deep hypersaline anoxic basins (DHABs) are marine extreme habitats, firstly discovered in the 1970s of the last century, located in several oceanographic regions, including the Mediterranean and Red Sea and the Gulf of Mexico. These basins are filled with brines that do not mix with the overlying seawater, due to a density difference. Brine and seawater result separated by a thick interface acting as a trap for particulate and cells. Some microbiological studies focused on seawater-brine interfaces of DHABs, showing that microbial populations are differentially distributed according to the gradient of salinity, oxygen, and nutrients occurring in such transition zones. Moreover, DHABs’ brines were intensively studied showing that specific bacterial, archaeal, and eukaryotic populations thrive there. In the last few years, cultivation and “omics”-based approaches have been used with samples collected from DHABs around the world, allowing clarifying metabolic processes of paramount ecological importance and pointing out the high biotechnological potential of the inhabiting extremophiles.

  15. Sodium toxicity and pathology associated with exposure of waterfowl to hypersaline playa lakes of southeast New Mexico

    Science.gov (United States)

    Meteyer, C.U.; Dubielzig, R.D.; Dein, F.J.; Baeten, L.A.; Moore, M.K.; Jehl, J.R.; Wesenberg, K.E.

    1997-01-01

    Cause of mortality was studied in waterfowl in hypersaline playa lakes of southeast New Mexico during spring and fall migration. Mortality was not common in wild ducks resting on the playas during good weather. However, when birds remained on the lakes for prolonged periods of time, such as during experimental trials and stormy weather, a heavy layer of salt precipitated on their feathers. Sodium toxicity was the cause of death for all experimental mallards housed on playa water and for 50% of the wild waterfowl found moribund or dead during the spring of 1995. Gross lesions included heavy salt precipitation on the feathers, ocular lens opacities, deeply congested brains, and dilated, thin-walled, fluid-filled cloacae. Microscopic lesions in the more severely affected birds included liquefaction of ocular lens cortex with lens fiber swelling and multifocal to diffuse ulcerative conjunctivitis with severe granulocytic inflammation, edema, and granulocytic vasculitis resulting in thrombosis. Inflammation similar to that seen in the conjunctiva occasionally involved the mucosa of the mouth, pharynx, nasal turbinates, cloaca, and bursa. Transcorneal movement of water in response to the hypersaline conditions on the playa lakes or direct contact with salt crystals could induce anterior segment dehydration of the aqueous humor and increased osmotic pressure on the lens, leading to cataract formation.

  16. Discovery of anaerobic lithoheterotrophic haloarchaea, ubiquitous in hypersaline habitats

    NARCIS (Netherlands)

    Sorokin, Dimitry Y.; Messina, Enzo; Smedile, Francesco; Roman, Pawel; Sinninghe Damsté, J.S.; Ciordia, Sergio; Mena, Maria Carmen; Ferrer, Manuel; Golyshin, Peter N.; Kublanov, Ilya V.

    2017-01-01

    Hypersaline anoxic habitats harbour numerous novel uncultured archaea whose metabolic and ecological roles remain to be elucidated. Until recently, it was believed that energy generation via dissimilatory reduction of sulfur compounds is not functional at salt saturation conditions. Recent

  17. Practicing on Newly Dead

    Directory of Open Access Journals (Sweden)

    Jewel Abraham

    2015-07-01

    Full Text Available A newly dead cadaver simulation is practiced on the physical remains of the dead before the onset of rigor mortis. This technique has potential benefits for providing real-life in-situ experience for novice providers in health care practices. Evolving ethical views in health care brings into question some of the ethical aspects associated with newly dead cadaver simulation in terms of justification for practice, autonomy, consent, and the need of disclosure. A clear statement of policies and procedures on newly dead cadaver simulation has yet to be implemented. Although there are benefits and disadvantages to an in-situ cadaver simulation, such practices should not be carried out in secrecy as there is no compelling evidence that suggests such training as imperative. Secrecy in these practices is a violation of honor code of nursing ethics. As health care providers, practitioners are obliged to be ethically honest and trustworthy to their patients. The author explores the ethical aspects of using newly dead cadaver simulation in training novice nursing providers to gain competency in various lifesaving skills, which otherwise cannot be practiced on a living individual. The author explores multiple views on cadaver simulation in relation to ethical theories and practices such as consent and disclosure to family.

  18. Dead or alive?

    OpenAIRE

    2006-01-01

    Dead or Alive was a painting and sound exhibition in the National Physical Laboratory (NPL) in Richmond. NPL is the UK’s national standards laboratory for metrology and is one of the world’s leading measurement institutes. \\ud \\ud The exhibition took the form of installations consisting of paintings and soundscapes set up in two spaces, an anechoic chamber (dead) and a reverberation chamber (alive). For the exhibition a new body of work was made including a twenty-seven-metre panoramic painti...

  19. Live and Dead Nodes

    DEFF Research Database (Denmark)

    Jørgensen, Sune Lehman; Jackson, A. D.

    2005-01-01

    In this paper, we explore the consequences of a distinction between `live' and `dead' network nodes; `live' nodes are able to acquire new links whereas `dead' nodes are static. We develop an analytically soluble growing network model incorporating this distinction and show that it can provide...... a quantitative description of the empirical network composed of citations and references (in- and out-links) between papers (nodes) in the SPIRES database of scientific papers in high energy physics. We also demonstrate that the death mechanism alone can result in power law degree distributions for the resulting...... network....

  20. Calibrated surface ages for desert pavements from spaceborne radar measurements of surface roughness and application of this new dating method for quantifying tectonic slip rates across the Dead Sea Transform since 1 Ma.

    Science.gov (United States)

    Hetz, Guy; Mushkin, Amit; Beyth, Michael; Baer, Gidon; Sagy, Amir; Blumberg, Dan; Ginat, Hanan

    2017-04-01

    The Dead Sea Transform (DST) accommodates a total of 105 km of sinistral motion between Arabia and the Sinai sub-plate since the Miocene. Previous studies revealed time-averaged slip rates of 5-8 mm/yr since the Miocene that appear to be comparable to more recent slip rates of 3-9 mm/yr inferred from offset late Pleistocene - Holocene geomorphic markers and GPS measurements along the DST. However, quantitative constraints for Plio-Pleistocene slip rates across the transform remain limited because dating efforts of geomorphic features in this age range that were tectonically offset by the DST have been unsuccessful so far. Here, to address this data gap we use a newly established dating approach for desert alluvial surfaces that builds on satellite radar measurements of surface roughness as quantitative proxies for the age of abandoned alluvial surfaces in desert environments. Calibration of the radar measurements against previously obtained 'in-situ' surface ages (e.g., cosmogenic nuclides, luminescence dating) of abandoned alluvial units within the DST region allowed us to use radar to determine surface ages. Sensitivity analyses and validation experiments reveal a minor dependency on lithology, an effective age inversion range of 3 - 1500 ka and overall uncertainty of 35% for the radar-based age estimates. Newly obtained radar ages of 700 and 1000 ka for tectonically offset alluvial fans, which could not be previously dated with 'in-situ' methods, reveal a constant lateral slip rate of 5-10 mm/yr across the DST since 1 Ma. Our results support the hypothesis that crustal velocities between Arabia and the Sinai sub-plate have remained constant since the Miocene.

  1. Orphans in the Dead Sea Scrolls

    African Journals Online (AJOL)

    2016-08-12

    Aug 12, 2016 ... Orphans are often mentioned in the literature of the ancient Near East, including the writings of the Hebrew Bible.1 These ... A few well-known examples from ancient Near Eastern texts should suffice to illustrate this point. A hymn to Nanshe says of the ...... Society, Israel Museum. Campbell, J.G., 1995, The ...

  2. Shifts in microbial community structure along an ecological gradient of hypersaline soils and sediments

    National Research Council Canada - National Science Library

    Hollister, Emily B; Engledow, Amanda S; Hammett, Amy Jo M; Provin, Tony L; Wilkinson, Heather H; Gentry, Terry J

    2010-01-01

    ..., hypersaline lake located in southern Texas, USA, were surveyed to characterize the structure and diversity of their microbial communities. Samples were collected along a transect that spanned vegetat...

  3. Development of a halotolerant community in the St. Lucia Estuary (South Africa) during a hypersaline phase

    National Research Council Canada - National Science Library

    Carrasco, Nicola K; Perissinotto, Renzo

    2012-01-01

    The St. Lucia Estuary, Africa's largest estuarine lake, is currently experiencing unprecedented freshwater deprivation which has resulted in a northward gradient of drought effects, with hypersaline...

  4. Ophiuroids discovered in the middle triassic hypersaline environment.

    Directory of Open Access Journals (Sweden)

    Mariusz A Salamon

    Full Text Available Echinoderms have long been considered to be one of the animal phyla that is strictly marine. However, there is growing evidence that some recent species may live in either brackish or hypersaline environments. Surprisingly, discoveries of fossil echinoderms in non-(openmarine paleoenvironments are lacking. In Wojkowice Quarry (Southern Poland, sediments of lowermost part of the Middle Triassic are exposed. In limestone layer with cellular structures and pseudomorphs after gypsum, two dense accumulations of articulated ophiuroids (Aspiduriella similis (Eck were documented. The sediments with ophiuroids were formed in environment of increased salinity waters as suggested by paleontological, sedimentological, petrographical and geochemical data. Discovery of Triassic hypersaline ophiuroids invalidates the paleontological assumption that fossil echinoderms are indicators of fully marine conditions. Thus caution needs to be taken when using fossil echinoderms in paleoenvironmental reconstructions.

  5. Mercury and lead tolerance in hypersaline sulfate-reducing bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Harithsa, S.; Kerkar, S.; LokaBharathi, P.A.

    found to be widely distributed in the marine and estuarine environments (Sanzgiry et al., 1988; George, 1988). Studies on metal microbe interactions are generally restrictedtoaerobicbacteria(Foster,1983;Aikingetal., 1985),anaerobicconsortia...(WhiteandGadd,1996)and sometimes to mesophilic SRB(Loka Bharathi et al., 1990).Thepresentworkhasexaminedtheinteractionof a few hypersaline isolates of SRBwith Hg and Pb at elevated concentrations of the metal salts, as saltpans * Corresponding author. Tel.: +91...

  6. Diel Migrations of Microorganisms within a Benthic, Hypersaline Mat Community

    OpenAIRE

    Garcia-Pichel, Ferran; Mechling, Margaret; Castenholz, Richard W.

    1994-01-01

    We studied the diel migrations of several species of microorganisms in a hypersaline, layered microbial mat. The migrations were quantified by repeated coring of the mat with glass capillary tubes. The resulting minicores were microscopically analyzed by using bright-field and epifluorescence (visible and infrared) microscopy to determine depths of coherent layers and were later dissected to determine direct microscopic counts of microorganisms. Microelectrode measurements of oxygen concentra...

  7. Dead-ice environments

    DEFF Research Database (Denmark)

    Krüger, Johannes; Kjær, Kurt H.; Schomacker, Anders

    2010-01-01

    Kötlujökull transports considerable amounts of supraglacial debris at its snout because of frontal oscillations with frequent ice advances followed by ice-margin stagnation. Kötlujökull provides suitable conditions of studying dead-ice melting and landscape formation in a debris-charged lowland...... under humid, sub-polar conditions? Does this rate differ from rates reported from polar environments of dry continental nature? How will the sedimentary architecture appear in the geological record? How will the final landsystem appear? These key questions are answered in a review of research...... and conclusions on dead-ice melting and landscape formation from Kötlujökull. Processes and landform-sediment associations are linked to the current climate and glacier–volcano interaction....

  8. Resurrecting deadly carrots

    DEFF Research Database (Denmark)

    Weitzel, Corinna; Rønsted, Nina; Spalik, Krysztof

    2014-01-01

    Thapsia L. circumscribes a small genus of herbaceous perennials in the taxonomically difficult family Apiaceae. Thapsia occurs around the Mediterranean, extending from the Atlantic coasts of Portugal and Morocco to Crete and other Greek Islands in the East. Thapsia is commonly known as deadly...... the species studied here from Ammodaucus, Distichoselinum, Elaeoselinum, Guillonea and Margotia in Thapsia in correspondence with previous phylogenetic studies of Apiaceae. Elaeoselinum is not monophyletic. Clades within Thapsia correlate well with previous observations of groupings based on the occurrence...

  9. Model reactions and natural occurrence of furans from hypersaline environments

    Directory of Open Access Journals (Sweden)

    T. Krause

    2014-05-01

    Full Text Available Volatile organic compounds like furan and its derivatives are important for atmospheric properties and reactions. In this work the known abiotic formation of furan from catechol under Fenton-like conditions with Fe3+ sulfate was revised by the use of a bispidine Fe2+ complex as a model compound for iron with well-known characteristics. While total yields were comparable to those with the Fe3+ salt, the bispidine Fe2+ complex is a better catalyst as the turnover numbers of the active iron species were higher. Additionally, the role of iron and pH is discussed in relation to furan formation from model compounds and in natural sediment and water samples collected from the Dead Sea and several salt lakes in Western Australia. Various alkylated furans and even traces of halogenated furans (3-chlorofuran and 3-bromofuran were found in some Australian samples. 3-chlorofuran was found in three sediments and four water samples, whereas 3-bromofuran was detected in three water samples. Further, the emission of furans is compared to the abundance of several possible precursors such as isoprene and aromatic hydrocarbons as well as to the related thiophenes. It is deduced that the emissions of volatile organic compounds such as furans contribute to the formation of ultra-fine particles in the vicinity of salt lakes and are important for the local climate.

  10. Dormant stages of crustaceans as a mechanism of propagation in the extreme and unpredictable environment in the Crimean hypersaline lakes

    Science.gov (United States)

    Shadrin, Nickolai V.; Anufriieva, Elena V.; Amat, Francisco; Eremin, Oleg Yu.

    2015-11-01

    A pool of dormant stages of planktonic organisms in saline lakes is a substantial component in the plankton communities; we need to take it into account to understand plankton dynamics. Hypersaline water bodies in Crimea, the largest peninsula in the Black Sea, constitute a very characteristic and peculiar habitat type in the region. We examined the presence of crustacean resting stages in sediments of dried up sites of the Crimean hypersaline lakes. Sediment samples were taken in 9 different lakes. Experiments performed on the hatching of these resting stages showed the presence of Moina salina (Cladocera), parthenogenetic Artemia and Artemia urmiana (Anostraca), Eucypris mareotica ( inflata) (Ostracoda), and Cletocamptus retrogressus (Harpacticoida). Comparing the experimental results obtained with clean dried brine shrimp cysts and those kept in sediment samples, it was noted that clean cysts hatched much faster than those from sediments did. Some components in bottom sediments slow down and desynchronize hatching from resting eggs in different groups of crustaceans. The sediments of different lakes inhibited the nauplii output from Artemia and ostracod resting eggs to different degrees. More data are needed before we can discuss the reasons of this inhibition. The nonsynchronous output of active stages from the bottom resting ones may be an adaptation that allows crustacean species to exist in extreme and unpredictably changing environments, avoiding the risk that all may emerge at once under unsuitable conditions.

  11. Hypersaline waters - a potential source of foodborne toxigenic aspergilli and penicillia

    DEFF Research Database (Denmark)

    Butinar, Lorena; Frisvad, Jens Christian; Gunde-Cimerman, Nina

    2011-01-01

    Previous studies of hypersaline environments have revealed the dominant presence of melanized yeast-like fungi and related Cladosporium spp. In this study, we focused on the genera Aspergillus and Penicillium and their teleomorphic forms. From oligotrophic and eutrophic hypersaline waters around ...

  12. The Dead Walk

    Directory of Open Access Journals (Sweden)

    Bill Phillips

    2014-02-01

    Full Text Available Monsters have always enjoyed a significant presence in the human imagination, and religion was instrumental in replacing the physical horror they engendered with that of a moral threat. Zombies, however, are amoral – their motivation purely instinctive and arbitrary, yet they are, perhaps, the most loathed of all contemporary monsters. One explanation for this lies in the theory of the uncanny valley, proposed by robotics engineer Masahiro Mori. According to the theory, we reserve our greatest fears for those things which seem most human, yet are not – such as dead bodies. Such a reaction is most likely a survival mechanism to protect us from danger and disease – a mechanism even more essential when the dead rise up and walk. From their beginnings zombies have reflected western societies’ greatest fears – be they of revolutionary Haitians, women, or communists. In recent years the rise in the popularity of the zombie in films, books and television series reflects our fears for the planet, the economy, and of death itself

  13. Biodiversity of the Hypersaline Urmia Lake National Park (NW Iran

    Directory of Open Access Journals (Sweden)

    Alireza Asem

    2014-02-01

    Full Text Available Urmia Lake, with a surface area between 4000 to 6000 km2, is a hypersaline lake located in northwest Iran. It is the saltiest large lake in the world that supports life. Urmia Lake National Park is the home of an almost endemic crustacean species known as the brine shrimp, Artemia urmiana. Other forms of life include several species of algae, bacteria, microfungi, plants, birds, reptiles, amphibians and mammals. As a consequence of this unique biodiversity, this lake has been selected as one of the 59 biosphere reserves by UNESCO. This paper provides a comprehensive species checklist that needs to be updated by additional research in the future.

  14. Hypogene and supergene alteration of the zeolite-bearing pyroclastic deposits at Tell Rimah, Jordan, and rift-related processes along the Dead-Sea-Transform Fault System during the Quaternary

    Science.gov (United States)

    Dill, H. G.; Techmer, A.; Botz, R.; Dohrmann, R.; Kaufhold, S.

    2012-09-01

    The boundary between the Arabian and African plates, is marked in the Middle East by one of the most prominent deep-seated lineamentary structures, called the Dead-Sea-Transform Fault System (DSTFS). Structural and mineralogical processes related to the DSTFS were correlated with equivalent processes leading to the alteration of pyroclastic deposits of alkali-olivine basaltic to nepheline basaltic composition which formed during a time span of less than 0.5 Ma. The large deposit of Tell Rimah, Jordan, is operated for the exploitation of zeolites, tuffs, and as pozzolana raw material. Four discrete stages of mineralizations have been distinguished from each other within these volcanic-hosted mineral deposits. (1) Hypogene syneruptive alteration of pyroclastic rocks produced siliceous gels ("allophane"), smectite, analcime, and phillipsite in vesicles when the groundwater level was low in the rift basin of the DSTFS. The lake-level lowstand caused the fluid system in the pyroclastic cone to become self-sufficient and it has been considered as a closed hydrothermal system. (2) Periods of tectonic and magmatic quiescence grinded the detrital sedimentation in the rift basin to a halt, while triggering a supergene alteration in the eruptive cones on the adjacent Arabian Plate. (3) Epigenetic alteration affected the pyroclastic rocks in the distal part of the DSTFS as a result of a rising water level. The water gradually filled the pore space of the permeable pyroclastic deposits almost to completeness and caused meniscus and blocky cements of calcite, phillipsite and chabazite to develop. In the rift basin, contemporaneously with the alteration of the pyroclastic rocks, freshwater limestones formed on calcareous bedrocks. Ba and Mn minerals in these freshwater limestones were supplied by subaquatic brines. Subsequently, a drastic lowering of the lake water level in the DSTFS converted the system of subaquatic freshwater limestones into subaerial tufa and travertine. As

  15. The Performing Dead

    DEFF Research Database (Denmark)

    Sabra, Jakob Borrits

    the surface of Vor Frelsers Cemetery, as the background for affective resonances of the un-seen and un-told networks that connect people with time, places and spaces, through media. By following a non-representational research approach the project tries to enliven this particular cemetery rather than report...... as functional assistant cemetery in 1790, the 1,66 Acre of Vor Frelser Cemetery have had significant cultural and emotional roothold in the citizens of Amager and the adjacent Copenhagen districts. Today it serves as both the traditional ritual space for the interment of the dead (bodies or cremated remains...... that convey a weave of bodies, sites and memories along with a bodily exploration of the city of Copenhagen. Here invisible life-traces and their way through the urban landscape are animated as a meshwork of relations between the real and the fictional, unfolding in the interplay between performance...

  16. Charlie: Dead Laughing

    Directory of Open Access Journals (Sweden)

    María del Socorro Tuirán Rougeon

    2017-01-01

    Full Text Available The article addresses the dramatic events of January 2015 in France, from the perspective of humor as an unconscious formation, as described by Freud. The deadly attack targeted the headquarters of Charlie Hebdo, a satirical journal that questions sensitive social issues through caricatures, cartoons, and humor. Considering that censure has always existed, what could explain this bloody act today? Can't we laugh at everything? Can't we laugh with anyone? While Freud suggests the hypothesis that the comic is a formation of spirit vis-à-vis the pain caused by existence, he also proposes that humor is the contribution of the super-ego to the comic. How, then, is it possible to understand that we cannot laugh at everything?

  17. Living at the Limits: Evidence for Microbial Eukaryotes Thriving under Pressure in Deep Anoxic, Hypersaline Habitats

    Directory of Open Access Journals (Sweden)

    Thorsten Stoeck

    2014-01-01

    Full Text Available The advent of molecular tools in microbial ecology paved the way to exploit the diversity of microbes in extreme environments. Here, we review these tools as applied in one of the most polyextreme habitats known on our planet, namely, deep hypersaline anoxic basins (DHABs, located at ca. 3000–3500 m depth in the Eastern Mediterranean Sea. Molecular gene signatures amplified from environmental DHAB samples identified a high degree of genetic novelty, as well as distinct communities in the DHABs. Canonical correspondence analyses provided strong evidence that salinity, ion composition, and anoxia were the strongest selection factors shaping protistan community structures, largely preventing cross-colonization among the individual basins. Thus, each investigated basin represents a unique habitat (“isolated islands of evolution”, making DHABs ideal model sites to test evolutionary hypotheses. Fluorescence in situ hybridization assays using specifically designed probes revealed that the obtained genetic signatures indeed originated from indigenous polyextremophiles. Electron microscopy imaging revealed unknown ciliates densely covered with prokaryote ectosymbionts, which may enable adaptations of eukaryotes to DHAB conditions. The research reviewed here significantly advanced our knowledge on polyextremophile eukaryotes, which are excellent models for a number of biological research areas, including ecology, diversity, biotechnology, evolutionary research, physiology, and astrobiology.

  18. Cooling, cryporitectant and hypersaline sensitivity of Penaeid shrimp embryos and nauplii larvae

    NARCIS (Netherlands)

    Alfaro Montoya, J.; Komen, J.; Huisman, E.A.

    2001-01-01

    The sensitivity of embryos of the penaeid shrimp, Trachypenaeus byrdi, to cooling, cryoprotectant exposure (dimethyl sulfoxide : DMSO, sucrose, methanol and glycerol), and hypersaline treatment was assessed in order to gain basic knowledge for cryopreservation procedures. In addition, cooling and

  19. Microbial lithification in marine stromatolites and hypersaline mats.

    Science.gov (United States)

    Dupraz, Christophe; Visscher, Pieter T

    2005-09-01

    Lithification in microbial ecosystems occurs when precipitation of minerals outweighs dissolution. Although the formation of various minerals can result from microbial metabolism, carbonate precipitation is possibly the most important process that impacts global carbon cycling. Recent investigations have produced models for stromatolite formation in open marine environments and lithification in shallow hypersaline lakes, which could be highly relevant for interpreting the rock record and searching for extraterrestrial life. Two factors that are controlled by microbial processes and physicochemical characteristics determine precipitation: exopolymeric substances and the saturation index, the latter being determined by the pH, {Ca(2+)} and {CO(3)(2-)}. Here, we evaluate community metabolism in microbial mats and hypothesize why these organosedimentary biofilms sometimes lithify and sometimes do not.

  20. New Abundant Microbial Groups in Aquatic Hypersaline Environments

    Science.gov (United States)

    Ghai, Rohit; Pašić, Lejla; Fernández, Ana Beatriz; Martin-Cuadrado, Ana-Belen; Mizuno, Carolina Megumi; McMahon, Katherine D.; Papke, R. Thane; Stepanauskas, Ramunas; Rodriguez-Brito, Beltran; Rohwer, Forest; Sánchez-Porro, Cristina; Ventosa, Antonio; Rodríguez-Valera, Francisco

    2011-01-01

    We describe the microbiota of two hypersaline saltern ponds, one of intermediate salinity (19%) and a NaCl saturated crystallizer pond (37%) using pyrosequencing. The analyses of these metagenomes (nearly 784 Mb) reaffirmed the vast dominance of Haloquadratum walsbyi but also revealed novel, abundant and previously unsuspected microbial groups. We describe for the first time, a group of low GC Actinobacteria, related to freshwater Actinobacteria, abundant in low and intermediate salinities. Metagenomic assembly revealed three new abundant microbes: a low-GC euryarchaeon with the lowest GC content described for any euryarchaeon, a high-GC euryarchaeon and a gammaproteobacterium related to Alkalilimnicola and Nitrococcus. Multiple displacement amplification and sequencing of the genome from a single archaeal cell of the new low GC euryarchaeon suggest a photoheterotrophic and polysaccharide-degrading lifestyle and its relatedness to the recently described lineage of Nanohaloarchaea. These discoveries reveal the combined power of an unbiased metagenomic and single cell genomic approach. PMID:22355652

  1. MILLIMETER-SCALE GENETIC GRADIENTS AND COMMUNITY-LEVEL MOLECULAR CONVERGENCE IN A HYPERSALINE MICROBIAL MAT

    Energy Technology Data Exchange (ETDEWEB)

    Fenner, Marsha W; Kunin, Victor; Raes, Jeroen; Harris, J. Kirk; Spear, John R.; Walker, Jeffrey J.; Ivanova, Natalia; Mering, Christian von; Bebout, Brad M.; Pace, Norman R.; Bork, Peer; Hugenholtz, Philip

    2008-04-30

    To investigate the extent of genetic stratification in structured microbial communities, we compared the metagenomes of 10 successive layers of a phylogenetically complex hypersaline mat from Guerrero Negro, Mexico. We found pronounced millimeter-scale genetic gradients that are consistent with the physicochemical profile of the mat. Despite these gradients, all layers displayed near identical and acid-shifted isoelectric point profiles due to a molecular convergence of amino acid usage indicating that hypersalinity enforces an overriding selective pressure on the mat community.

  2. Anthrax, People and Dead Hippos

    Centers for Disease Control (CDC) Podcasts

    2017-11-07

    Epidemiologist, Dr. Melissa Marx, discuses anthrax deaths in people who ate dead hippos.  Created: 11/7/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/7/2017.

  3. Differences in lateral gene transfer in hypersaline versus thermal environments

    Directory of Open Access Journals (Sweden)

    House Christopher H

    2011-07-01

    Full Text Available Abstract Background The role of lateral gene transfer (LGT in the evolution of microorganisms is only beginning to be understood. While most LGT events occur between closely related individuals, inter-phylum and inter-domain LGT events are not uncommon. These distant transfer events offer potentially greater fitness advantages and it is for this reason that these "long distance" LGT events may have significantly impacted the evolution of microbes. One mechanism driving distant LGT events is microbial transformation. Theoretically, transformative events can occur between any two species provided that the DNA of one enters the habitat of the other. Two categories of microorganisms that are well-known for LGT are the thermophiles and halophiles. Results We identified potential inter-class LGT events into both a thermophilic class of Archaea (Thermoprotei and a halophilic class of Archaea (Halobacteria. We then categorized these LGT genes as originating in thermophiles and halophiles respectively. While more than 68% of transfer events into Thermoprotei taxa originated in other thermophiles, less than 11% of transfer events into Halobacteria taxa originated in other halophiles. Conclusions Our results suggest that there is a fundamental difference between LGT in thermophiles and halophiles. We theorize that the difference lies in the different natures of the environments. While DNA degrades rapidly in thermal environments due to temperature-driven denaturization, hypersaline environments are adept at preserving DNA. Furthermore, most hypersaline environments, as topographical minima, are natural collectors of cellular debris. Thus halophiles would in theory be exposed to a greater diversity and quantity of extracellular DNA than thermophiles.

  4. Enhanced bioremediation of oil-polluted, hypersaline, coastal areas in Kuwait via vitamin-fertilization.

    Science.gov (United States)

    Al-Mailem, Dina M; Eliyas, Mohamed; Radwan, Samir

    2014-03-01

    There is no research published sofar on managements that could bioremediate hypersaline soils and water polluted with hydrocarbons. The objective of this study was to assess the effect of vitamin amendment on hydrocarbon removal by microorganisms indigenous to such hypersaline environments. We used in this study ten hydrocarbonoclastic bacterial species and five archaeal species that had been isolated by the conventional plating method on media containing oil as a sole carbon source, from a hypersaline (3-4 M NaCl) coastal area in Kuwait, and characterized by sequencing of their 16S rRNA coding genes. The oil and pure hydrocarbon consumption was measured by gas-liquid chromatography. The oil and pure hydrocarbon consumption potential of all microorganisms in media with hypersalinity was enhanced by vitamin fertilization. This was true for individual microorganisms in pure cultures as well as for microbial consortia in hypersaline soil and water samples used as inocula. Most effective vitamins were thiamin, pyridoxine and vitamin B12. Vitamin fertilization using vitamin rich wastes or byproducts could be an effective practice for enhancing bioremediation of oil contaminated hypersaline environments.

  5. Dead Star Rumbles

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Composite of Supernova Remnant Cassiopeia A This Spitzer Space Telescope composite shows the supernova remnant Cassiopeia A (white ball) and surrounding clouds of dust (gray, orange and blue). It consists of two processed images taken one year apart. Dust features that have not changed over time appear gray, while those that have changed are colored blue or orange. Blue represents an earlier time and orange, a later time. These observations illustrate that a blast of light from Cassiopeia A is waltzing outward through the dusty skies. This dance, called an 'infrared echo,' began when the remnant erupted about 50 years ago. Cassiopeia A is the remnant of a once massive star that died in a violent supernova explosion 325 years ago. It consists of a dead star, called a neutron star, and a surrounding shell of material that was blasted off as the star died. This remnant is located 10,000 light-years away in the northern constellation Cassiopeia. An infrared echo is created when a star explodes or erupts, flashing light into surrounding clumps of dust. As the light zips through the dust clumps, it heats them up, causing them to glow successively in infrared, like a chain of Christmas bulbs lighting up one by one. The result is an optical illusion, in which the dust appears to be flying outward at the speed of light. This apparent motion can be seen here by the shift in colored dust clumps. Echoes are distinct from supernova shockwaves, which are made up material that is swept up and hurled outward by exploding stars. This infrared echo is the largest ever seen, stretching more than 50 light-years away from Cassiopeia A. If viewed from Earth, the entire movie frame would take up the same amount of space as two full moons. Hints of an older infrared echo from Cassiopeia A's supernova explosion hundreds of years ago can also be seen. The earlier Spitzer image was taken on November 30, 2003, and the later, on December 2, 2004.

  6. 46 CFR 171.117 - Dead covers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Dead covers. 171.117 Section 171.117 Shipping COAST... Dead covers. (a) Except as provided in paragraph (b) of this section, each port light with the sill located below the margin line must have a hinged, inside dead cover. (b) The dead cover on a port light...

  7. Resilience of estuarine phytoplankton and their temporal variability along salinity gradients during drought and hypersalinity

    Science.gov (United States)

    Nche-Fambo, F. A.; Scharler, U. M.; Tirok, K.

    2015-06-01

    In South African estuaries, there is no knowledge on the resilience and variability in phytoplankton communities under conditions of hypersalinity, extended droughts and reverse salinity gradients. Phytoplankton composition, abundance and biomass vary with changes in environmental variables and taxa richness declines specifically under hypersaline conditions. This research thus investigated the phytoplankton community composition, its resilience and variability under highly variable and extreme environmental conditions in an estuarine lake system (Lake St. Lucia, South Africa) over one year. The lake system was characterised by a reverse salinity gradient with hypersalinity furthest from the estuarine inlet during the study period. During this study, 78 taxa were recorded: 56 diatoms, eight green algae, one cryptophyte, seven cyanobacteria and six dinoflagellates. Taxon variability and resilience depended on their ability to tolerate high salinities. Consequently, the phytoplankton communities as well as total abundance and biomass differed along the salinity gradient and over time with salinity as the main determinant. Cyanobacteria were dominant in hypersaline conditions, dinoflagellates in marine-brackish salinities, green algae and cryptophytes in lower salinities (brackish) and diatoms were abundant in marine-brackish salinities but survived in hypersaline conditions. Total abundance and biomass ranged from 3.66 × 103 to 1.11 × 109 Cells/L and 1.21 × 106 to 1.46 × 1010 pgC/L respectively, with the highest values observed under hypersaline conditions. Therefore, even under highly variable, extreme environmental conditions and hypersalinity the phytoplankton community as a whole was resilient enough to maintain a relatively high biomass throughout the study period. The resilience of few dominant taxa, such as Cyanothece, Spirulina, Protoperidinium and Nitzschia and the dominance of other common genera such as Chlamydomonas, Chroomonas, Navicula, Gyrosigma

  8. Lipid Biomarkers for a Hypersaline Microbial Mat Community

    Science.gov (United States)

    Jahnke, Linda; Orphan, Victoria; Embaye, Tsegereda; Turk, Kendra; Kubo, Mike; Summons, Roger

    2004-01-01

    The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. Various lipids associated with specific microbial groups can serve as biomarkers for establishing organism source and function in contemporary microbial ecosystems (membrane lipids), and by analogy, potential relevance to ancient organic-rich sedimentary rocks (geolipids). As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments. Our recent work has focused on lipid biomarker analysis of a potential analogue for such ancient mats growing in a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico. The aerobic, surface layer of this mat (0 to 1 mm) contained a variety of ester-bound fatty acids (FA) representing a diverse bacterial population including cyanobacteria, sulphate reducers (SRB) and heterotrophs. Biomarkers for microeukaryotes detected in this layer included sterols, C-20 polyunsaturated FA and a highly branched isoprenoid, diagnostic for diatoms. Cyanobacteria were also indicated by the presence of a diagnostic set of mid-chain methylalkanes. C-28, to C-34 wax esters (WXE) present in relatively small amounts in the upper 3 mm of the mat are considered biomarkers for green non-sulphur bacteria. Ether-bound isoprenoids were also identified although in considerably lower abundance than ester-bound FA (approx. 1:l0). These complex ether lipids included archatol, hydroxyarchaeol and a C-40 tetraether, all in small amounts. After ether cleavage with boron tribromide, the major recovered isoprenyl was a C-30:1. This C(sub 30;1) yelded squalane after hydrogenation, a known geobiomarker for hypersaline environments in ancient oils and sediments. In this mat, it represents the dominant Archaeal population. The carbon isotopic composition of biomarker lipids were generally depleted relative to the bulk organic material (delta C-13 TOC -10%). Most

  9. The Right to be Dead

    DEFF Research Database (Denmark)

    Sabra, Jakob Borrits; Troyer, John Eric

    2018-01-01

    illustrate our essay design arguments through the competition’s history and results. In our paper we argue that designing future cemeteries should focus on how spaces such as Arnos Vale represent a transitional hybrid space. A merger of the Victorian past with the digital present, in order to create a new...... kind of archival future. Future Cemeteries will ultimately become spaces where both dead humans and dead data are stored. The irony, of course, is that given current design conditions and limitations in thinking, Arnos Vale’s granite headstones will remain in situ long after today’s ‘internet’ has...

  10. Resurrecting Dead-water Phenomenon

    CERN Document Server

    Mercier, Matthieu; Dauxois, Thierry

    2011-01-01

    We revisit experimental studies performed by Ekman on dead-water using modern techniques in order to present new insights on this peculiar phenomenon. We extend its description to more general situations such as a three-layer fluid or a linearly stratified fluid in presence of a pycnocline, showing the robustness of dead-water phenomenon. We observe large amplitude nonlinear internal waves which are coupled to the boat dynamics, and we emphasize that the modeling of the wave-induced drag requires more analysis, taking into account nonlinear effects.

  11. Effect of hypersaline cooling canals on aquifer salinization

    Science.gov (United States)

    Hughes, Joseph D.; Langevin, Christian D.; Brakefield-Goswami, Linzy

    2010-01-01

    The combined effect of salinity and temperature on density-driven convection was evaluated in this study for a large (28 km2) cooling canal system (CCS) at a thermoelectric power plant in south Florida, USA. A two-dimensional cross-section model was used to evaluate the effects of hydraulic heterogeneities, cooling canal salinity, heat transport, and cooling canal geometry on aquifer salinization and movement of the freshwater/saltwater interface. Four different hydraulic conductivity configurations, with values ranging over several orders of magnitude, were evaluated with the model. For all of the conditions evaluated, aquifer salinization was initiated by the formation of dense, hypersaline fingers that descended downward to the bottom of the 30-m thick aquifer. Saline fingers reached the aquifer bottom in times ranging from a few days to approximately 5 years for the lowest hydraulic conductivity case. Aquifer salinization continued after saline fingers reached the aquifer bottom and coalesced by lateral movement away from the site. Model results showed that aquifer salinization was most sensitive to aquifer heterogeneity, but was also sensitive to CCS salinity, temperature, and configuration.

  12. Archaeal Communities in a Heterogeneous Hypersaline-Alkaline Soil

    Science.gov (United States)

    Navarro-Noya, Yendi E.; Valenzuela-Encinas, César; Sandoval-Yuriar, Alonso; Jiménez-Bueno, Norma G.; Marsch, Rodolfo

    2015-01-01

    In this study the archaeal communities in extreme saline-alkaline soils of the former lake Texcoco, Mexico, with electrolytic conductivities (EC) ranging from 0.7 to 157.2 dS/m and pH from 8.5 to 10.5 were explored. Archaeal communities in the 0.7 dS/m pH 8.5 soil had the lowest alpha diversity values and were dominated by a limited number of phylotypes belonging to the mesophilic Candidatus Nitrososphaera. Diversity and species richness were higher in the soils with EC between 9.0 and 157.2 dS/m. The majority of OTUs detected in the hypersaline soil were members of the Halobacteriaceae family. Novel phylogenetic branches in the Halobacteriales class were detected in the soil, and more abundantly in soil with the higher pH (10.5), indicating that unknown and uncharacterized Archaea can be found in this soil. Thirteen different genera of the Halobacteriaceae family were identified and were distributed differently between the soils. Halobiforma, Halostagnicola, Haloterrigena, and Natronomonas were found in all soil samples. Methanogenic archaea were found only in soil with pH between 10.0 and 10.3. Retrieved methanogenic archaea belonged to the Methanosarcinales and Methanomicrobiales orders. The comparison of the archaeal community structures considering phylogenetic information (UniFrac distances) clearly clustered the communities by pH. PMID:26074731

  13. Archaeal Communities in a Heterogeneous Hypersaline-Alkaline Soil

    Directory of Open Access Journals (Sweden)

    Yendi E. Navarro-Noya

    2015-01-01

    Full Text Available In this study the archaeal communities in extreme saline-alkaline soils of the former lake Texcoco, Mexico, with electrolytic conductivities (EC ranging from 0.7 to 157.2 dS/m and pH from 8.5 to 10.5 were explored. Archaeal communities in the 0.7 dS/m pH 8.5 soil had the lowest alpha diversity values and were dominated by a limited number of phylotypes belonging to the mesophilic Candidatus Nitrososphaera. Diversity and species richness were higher in the soils with EC between 9.0 and 157.2 dS/m. The majority of OTUs detected in the hypersaline soil were members of the Halobacteriaceae family. Novel phylogenetic branches in the Halobacteriales class were detected in the soil, and more abundantly in soil with the higher pH (10.5, indicating that unknown and uncharacterized Archaea can be found in this soil. Thirteen different genera of the Halobacteriaceae family were identified and were distributed differently between the soils. Halobiforma, Halostagnicola, Haloterrigena, and Natronomonas were found in all soil samples. Methanogenic archaea were found only in soil with pH between 10.0 and 10.3. Retrieved methanogenic archaea belonged to the Methanosarcinales and Methanomicrobiales orders. The comparison of the archaeal community structures considering phylogenetic information (UniFrac distances clearly clustered the communities by pH.

  14. Biogeography of Nocardiopsis strains from hypersaline environments of Yunnan and Xinjiang Provinces, western China

    Science.gov (United States)

    He, Song-Tao; Zhi, Xiao-Yang; Jiang, Hongchen; Yang, Ling-Ling; Wu, Jin-Yuan; Zhang, Yong-Guang; Hozzein, Wael N.; Li, Wen-Jun

    2015-01-01

    The genus Nocardiopsis is a widespread group within the phylum Actinobacteria and has been isolated from various salty environments worldwide. However, little is known about whether biogeography affects Nocardiopsis distribution in various hypersaline environments. Such information is essential for understanding the ecology of Nocardiopsis. Here we analyzed 16S rRNA, gyrB, rpoB and sodA genes of 78 Nocardiopsis strains isolated from hypersaline environments in Yunnan and Xinjiang Provinces of western China. The obtained Nocardiopsis strains were classified into five operational taxonomic units, each comprising location-specific phylo- and genotypes. Statistical analyses showed that spatial distance and environmental factors substantially influenced Nocardiopsis distribution in hypersaline environments: the former had stronger influence at large spatial scales, whereas the latter was more influential at small spatial scales. PMID:26289784

  15. Microbial fuel cells in saline and hypersaline environments: Advancements, challenges and future perspectives.

    Science.gov (United States)

    Grattieri, Matteo; Minteer, Shelley D

    2017-12-09

    This review is aimed to report the possibility to utilize microbial fuel cells for the treatment of saline and hypersaline solutions. An introduction to the issues related with the biological treatment of saline and hypersaline wastewater is reported, discussing the limitation that characterizes classical aerobic and anaerobic digestions. The microbial fuel cell (MFC) technology, and the possibility to be applied in the presence of high salinity, is discussed before reviewing the most recent advancements in the development of MFCs operating in saline and hypersaline conditions, with their different and interesting applications. Specifically, the research performed in the last 5years will be the main focus of this review. Finally, the future perspectives for this technology, together with the most urgent research needs, are presented. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. The genus Eurotium - members of indigenous fungal community in hypersaline waters of salterns.

    Science.gov (United States)

    Butinar, Lorena; Zalar, Polona; Frisvad, Jens C; Gunde-Cimerman, Nina

    2005-01-01

    Six different species of the known teleomorphic food-borne xerophilic genus Eurotium were repeatedly isolated in a mycodiversity study of hypersaline waters. At salinities above 17% NaCl, E. amstelodami was detected most consistently, followed by E. repens and E. herbariorum, while E. rubrum, E. chevalieri and a potentially new species, "Eurotium halotolerans", were detected only occasionally at lower salinities. The qualitative secondary metabolite profiles produced by Eurotium spp. from salterns were not different from those of Eurotium spp. from foods and other habitats. Spatiotemporal frequency of occurrence and in vitro determined adaptive ability of propagules to survive prolonged exposure to hypersaline conditions indicate that E. amstelodami, E. herbariorum, and E. repens contribute to the indigenous fungal community in hypersaline water environments, while E. rubrum, E. chevalieri and "E. halotolerans" are only temporal inhabitants of brine at lower salinities.

  17. Colloid transport in porous media: impact of hyper-saline solutions.

    Science.gov (United States)

    Magal, Einat; Weisbrod, Noam; Yechieli, Yoseph; Walker, Sharon L; Yakirevich, Alexander

    2011-05-01

    The transport of colloids suspended in natural saline solutions with a wide range of ionic strengths, up to that of Dead Sea brines (10(0.9) M) was explored. Migration of microspheres through saturated sand columns of different sizes was studied in laboratory experiments and simulated with mathematical models. Colloid transport was found to be related to the solution salinity as expected. The relative concentration of colloids at the columns outlet decreased (after 2-3 pore volumes) as the solution ionic strength increased until a critical value was reached (ionic strength > 10(-1.8) M) and then remained constant above this level of salinity. The colloids were found to be mobile even in the extremely saline brines of the Dead Sea. At such high ionic strength no energetic barrier to colloid attachment was presumed to exist and colloid deposition was expected to be a favorable process. However, even at these salinity levels, colloid attachment was not complete and the transport of ∼ 30% of the colloids through the 30-cm long columns was detected. To further explore the deposition of colloids on sand surfaces in Dead Sea brines, transport was studied using 7-cm long columns through which hundreds of pore volumes were introduced. The resulting breakthrough curves exhibited a bimodal shape whereby the relative concentration (C/C(0)) of colloids at the outlet rose to a value of 0.8, and it remained relatively constant (for the ∼ 18 pore volumes during which the colloid suspension was flushed through the column) and then the relative concentration increased to a value of one. The bimodal nature of the breakthrough suggests different rates of colloid attachment. Colloid transport processes were successfully modeled using the limited entrapment model, which assumes that the colloid attachment rate is dependent on the concentration of the attached colloids. Application of this model provided confirmation of the colloid aggregation and their accelerated attachment during

  18. FAQ: West Nile Virus and Dead Birds

    Science.gov (United States)

    ... Related Links Mosquito Surveillance Software West Nile Virus & Dead Birds Recommend on Facebook Tweet Share Compartir On ... What should I do if I find a dead bird? State and local agencies have different policies ...

  19. Geo- and Biogeochemical Processes in a Heliothermal Hypersaline Lake

    Energy Technology Data Exchange (ETDEWEB)

    Zachara, John M.; Moran, James J.; Resch, Charles T.; Lindemann, Stephen R.; Felmy, Andrew R.; Bowden, Mark E.; Cory, Alexandra B.; Fredrickson, Jim K.

    2016-03-17

    Water chemical variations were investigated over three annual hydrologic cycles in hypersaline, heliothermal, meromictic Hot Lake in north-central Washington State, USA. The lake, originally studied by Anderson (1958), contains diverse biota with dramatic zonation related to salinity and redox state. Water samples were collected at 10 cm depth intervals through the shallow lake (2.4 m) at a consistent location during 2012-2014, with comprehensive monitoring performed in 2013. Inorganic salt species, total dissolved solids (TDS), dissolved carbon forms (DOC, DIC), oxygen, sulfide, and methane were analyzed in lake water samples. Depth sonde measurements of pH and temperature were also performed to track their seasonal variations. A bathymetric survey of the lake was conducted to enable lake water volume and solute inventory calculations. Sediment cores were collected at low water and analyzed by x-ray diffraction to investigate sediment mineralogy. The primary dissolved salt in Hot Lake water was Mg2+-SO42- while sediments were dominated by gypsum (CaSO4•2H2O). Lake water concentrations increased with depth to reach saturation with epsomite that was exposed at lake bottom. At maximum volume in spring, Hot Lake exhibited a relatively dilute mixolimnion containing phyto- and zooplankton; a lower saline metalimnion with stratified oxygenic and anoxygenic photosynthetic microbiologic communities; and a stable, hypersaline monimolimnion, separated from above layers by a chemocline, containing high levels of sulfide and methane. The thickness of the mixolimnion regulates a heliothermal effect which creates temperatures in excess of 60 oC in the underlying metalimnion and monimolimnion. The mixolimnion was dynamic and actively mixed. It displayed large pH variations, in-situ calcium carbonate precipitation, and large evaporative volume losses. The depletion of this ephemeral layer by fall allowed deeper mixing into the volume-stable lower mixolimnion, more rapid heat

  20. Geo- and biogeochemical processes in a heliothermal hypersaline lake

    Science.gov (United States)

    Zachara, John M.; Moran, James J.; Resch, Charles T.; Lindemann, Stephen R.; Felmy, Andrew R.; Bowden, Mark E.; Cory, Alexandra B.; Fredrickson, James K.

    2016-05-01

    Water chemical variations were investigated over three annual hydrologic cycles in hypersaline, heliothermal, meromictic Hot Lake in north-central Washington State, USA. The lake contains diverse biota with dramatic zonation related to salinity and redox state. Water samples were collected at 10-cm depth intervals through the shallow lake (2.4 m) during 2012-2014, with comprehensive monitoring performed in 2013. Inorganic salt species, dissolved carbon forms (DOC, DIC), oxygen, sulfide, and methane were analyzed in lake water samples. Depth sonde measurements of pH and temperature were also performed to track their seasonal variations. A bathymetric survey of the lake was conducted to enable lake water volume and solute inventory calculations. Sediment cores were collected at low water and analyzed by X-ray diffraction to investigate sediment mineralogy. The primary dissolved salt in Hot Lake water was Mg2+-SO42- whereas sediments were dominated by gypsum (CaSO4·2H2O). Lake water concentrations increased with depth, reaching saturation with epsomite (MgSO4·7H2O) that was exposed at lake bottom. At maximum volume in spring, Hot Lake exhibited a relatively dilute mixolimnion; a lower saline metalimnion with stratified oxygenic and anoxygenic photosynthetic microbiological communities; and a stable, hypersaline monimolimnion, separated from above layers by a chemocline, containing high levels of sulfide and methane. The thickness of the mixolimnion regulates a heliothermal effect that creates temperatures in excess of 60 °C in the underlying metalimnion and monimolimnion. The mixolimnion was dynamic in volume and actively mixed. It displayed large pH variations, in-situ calcium carbonate precipitation, and large evaporative volume losses. The depletion of this layer by fall allowed deeper mixing into the metalimnion, more rapid heat exchange, and lower winter lake temperatures. Solubility calculations indicate seasonal biogenic and thermogenic aragonite

  1. Diel Metagenomics and Metatranscriptomics of Elkhorn Slough Hypersaline Microbial Mat

    Science.gov (United States)

    Lee, J.; Detweiler, A. M.; Everroad, R. C.; Bebout, L. E.; Weber, P. K.; Pett-Ridge, J.; Bebout, B.

    2014-12-01

    To understand the variation in gene expression associated with the daytime oxygenic phototrophic and nighttime fermentation regimes seen in hypersaline microbial mats, a contiguous mat piece was subjected to sampling at regular intervals over a 24-hour diel period. Additionally, to understand the impact of sulfate reduction on biohydrogen consumption, molybdate was added to a parallel experiment in the same run. 4 metagenome and 12 metatranscriptome Illumina HiSeq lanes were completed over day / night, and control / molybdate experiments. Preliminary comparative examination of noon and midnight metatranscriptomic samples mapped using bowtie2 to reference genomes has revealed several notable results about the dominant mat-building cyanobacterium Microcoleus chthonoplastes PCC 7420. Dominant cyanobacterium M. chthonoplastes PCC 7420 shows expression in several pathways for nitrogen scavenging, including nitrogen fixation. Reads mapped to M. chthonoplastes PCC 7420 shows expression of two starch storage and utilization pathways, one as a starch-trehalose-maltose-glucose pathway, another through UDP-glucose-cellulose-β-1,4 glucan-glucose pathway. The overall trend of gene expression was primarily light driven up-regulation followed by down-regulation in dark, while much of the remaining expression profile appears to be constitutive. Co-assembly of quality-controlled reads from 4 metagenomes was performed using Ray Meta with progressively smaller K-mer sizes, with bins identified and filtered using principal component analysis of coverages from all libraries and a %GC filter, followed by reassembly of the remaining co-assembly reads and binned reads. Despite having relatively similar abundance profiles in each metagenome, this binning approach was able to distinctly resolve bins from dominant taxa, but also sulfate reducing bacteria that are desired for understanding molybdate inhibition. Bins generated from this iterative assembly process will be used for downstream

  2. Diel Migrations of Microorganisms within a Benthic, Hypersaline Mat Community.

    Science.gov (United States)

    Garcia-Pichel, F; Mechling, M; Castenholz, R W

    1994-05-01

    We studied the diel migrations of several species of microorganisms in a hypersaline, layered microbial mat. The migrations were quantified by repeated coring of the mat with glass capillary tubes. The resulting minicores were microscopically analyzed by using bright-field and epifluorescence (visible and infrared) microscopy to determine depths of coherent layers and were later dissected to determine direct microscopic counts of microorganisms. Microelectrode measurements of oxygen concentration, fiber optic microprobe measurements of light penetration within the mat, and incident irradiance measurements accompanied the minicore sampling. In addition, pigment content, photosynthesis and irradiance responses, the capacity for anoxygenic photosynthesis, and gliding speeds were determined for the migrating cyanobacteria. Heavily pigmented Oscillatoria sp. and Spirulina cf. subsalsa migrated downward into the mat during the early morning and remained deep until dusk, when upward migration occurred. The mean depth of the migration (not more than 0.4 to 0.5 mm) was directly correlated with the incident irradiance over the mat surface. We estimated that light intensity at the upper boundary of the migrating cyanobacteria was attenuated to such an extent that photoinhibition was effectively avoided but that intensities which saturated photosynthesis were maintained through most of the daylight hours. Light was a cue of paramount importance in triggering and modulating the migration of the cyanobacteria, even though the migrating phenomenon could not be explained solely in terms of a light response. We failed to detect diel migration patterns for other cyanobacterial species and filamentous anoxyphotobacteria. The sulfide-oxidizing bacterium Beggiatoa sp. migrated as a band that followed low oxygen concentrations within the mat during daylight hours. During the nighttime, part of this population migrated toward the mat surface, but a significant proportion remained deep.

  3. 32 CFR 632.4 - Deadly force.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Deadly force. 632.4 Section 632.4 National... INVESTIGATIONS USE OF FORCE BY PERSONNEL ENGAGED IN LAW ENFORCEMENT AND SECURITY DUTIES § 632.4 Deadly force. (a) Deadly force is destructive physical force directed against a person or persons (e.g., firing a lethal...

  4. Global risk of deadly heat

    Science.gov (United States)

    Mora, Camilo; Dousset, Bénédicte; Caldwell, Iain R.; Powell, Farrah E.; Geronimo, Rollan C.; Bielecki, Coral R.; Counsell, Chelsie W. W.; Dietrich, Bonnie S.; Johnston, Emily T.; Louis, Leo V.; Lucas, Matthew P.; McKenzie, Marie M.; Shea, Alessandra G.; Tseng, Han; Giambelluca, Thomas W.; Leon, Lisa R.; Hawkins, Ed; Trauernicht, Clay

    2017-07-01

    Climate change can increase the risk of conditions that exceed human thermoregulatory capacity. Although numerous studies report increased mortality associated with extreme heat events, quantifying the global risk of heat-related mortality remains challenging due to a lack of comparable data on heat-related deaths. Here we conducted a global analysis of documented lethal heat events to identify the climatic conditions associated with human death and then quantified the current and projected occurrence of such deadly climatic conditions worldwide. We reviewed papers published between 1980 and 2014, and found 783 cases of excess human mortality associated with heat from 164 cities in 36 countries. Based on the climatic conditions of those lethal heat events, we identified a global threshold beyond which daily mean surface air temperature and relative humidity become deadly. Around 30% of the world's population is currently exposed to climatic conditions exceeding this deadly threshold for at least 20 days a year. By 2100, this percentage is projected to increase to ~48% under a scenario with drastic reductions of greenhouse gas emissions and ~74% under a scenario of growing emissions. An increasing threat to human life from excess heat now seems almost inevitable, but will be greatly aggravated if greenhouse gases are not considerably reduced.

  5. Thiohalospira halophila gen. nov., sp. nov. and Thiohalospira alkaliphila sp. nov., novel obligately chemolithoautotrophic, halophilic, sulfur-oxidizing gammaproteobacteria from hypersaline habitats.

    Science.gov (United States)

    Sorokin, Dimitry Yu; Tourova, Tatjana P; Muyzer, Gerard; Kuenen, Gijs J

    2008-07-01

    A previously unknown ecotype of obligately chemolithoautotrophic, sulfur-oxidizing bacteria was discovered in sediments of various inland hypersaline lakes and a solar saltern. The salt requirements for these bacteria were similar to those of haloarchaea, representing the first example of extreme halophiles occurring among the chemolithoautotrophs. They were enriched and isolated at 4 M NaCl under aerobic conditions with thiosulfate or tetrathionate as the electron donor or under micro-oxic conditions with sulfide. In total, 20 strains were obtained from hypersaline inland lakes in central Asia, central Russia and Crimea and a sea saltern of the Adriatic Sea. The isolates were thin, motile spirilla, some of which possessed a yellow, membrane-bound pigment. They were obligately aerobic, chemolithoautotrophic, sulfur-oxidizing bacteria that used thiosulfate, sulfide, sulfur and tetrathionate as electron donors. The characteristic feature of the group was the production of large amounts of tetrathionate as an intermediate during the oxidation of thiosulfate to sulfate. All but one of the strains grew within the pH range 6.5-8.2 (optimally at pH 7.3-7.8) and at NaCl concentrations from 2.0 to 5 M (optimally at 3.0 M). A single strain, designated ALgr 6sp(T), obtained (by enrichment) from the hypersaline alkaline lakes of the Wadi Natrun valley, was found to be moderately halophilic and facultatively alkaliphilic (capable of growth at pH 10). The predominant cellular fatty acids were quite unusual, with 10-methyl C(16 : 0) and C(16 : 0) predominating. Cells grown at 4 M NaCl accumulated extremely high concentrations of glycine betaine as a compatible solute. The 20 neutrophilic isolates contained three genospecies (on the basis of DNA-DNA relatedness data) but could not be discriminated phenotypically. On the basis of the phenotypic and genotypic analyses, the isolates constitute a novel genus and species, for which the name Thiohalospira halophila gen. nov., sp. nov

  6. Lake St Lucia, Africa’s largest estuarine lake in crisis: Combined effects of mouth closure, low levels and hypersalinity

    Directory of Open Access Journals (Sweden)

    Fiona MacKay

    2011-03-01

    Full Text Available The Lake St Lucia estuarine system is the most important nursery ground for juvenile marine fish and prawns along the KwaZulu-Natal coast. The estuary mouth closed in June 2002 because of drought and remained so for 4 years and 9 months. A study to determine the impacts of extended mouth closure, hypersalinity and low lake levels on the mesozooplankton, macrobenthic invertebrates and fish fauna was initiated in 2004. Zooplankton and benthic invertebrate diversity declined, benthic invertebrate community composition changed and the diversity and abundance of fish decreased between 2004 and 2007. In the case of fish, the declines were related to die-offs in the lake and the failed recruitment of post-larvae and juveniles from the marine environment as a result of the mouth having been closed. Options for management intervention under closed-mouth conditions are limited at this time, particularly in the short term, to breaching the mouth and facilitating the inflow of sea water. In the medium term, as was the historical situation, the reconnection of the Mfolozi system to St Lucia should be viewed as a major priority.

  7. Diversity and distribution of Halomonas in Rambla Salada, a hypersaline environment in the southeast of Spain

    NARCIS (Netherlands)

    Oueriaghli, N.; González-Domenech, C.M.; Martínez-Checa, F.; Muyzer, G.; Ventosa, A.; Quesada, E; Béjar, V.

    2014-01-01

    We have studied the diversity and distribution of Halomonas populations in the hypersaline habitat Rambla Salada (Murcia, southeastern Spain) by using different molecular techniques. Denaturing gradient gel electrophoresis (DGGE) using specific primers for the 16S rRNA gene of Halomonas followed by

  8. Is Piaget's epistemic subject dead?

    Science.gov (United States)

    Lawson, Anton E.

    Niaz (1990) presents arguments in favor of the retention of Piaget's epistemic subject as a theoretical construct to guide research and practice in science education and psychology. The intent of this article is to point out the weaknesses of those arguments and to suggest that the weight of evidence argues against the existence of the logical thinker postulated by Piaget. Therefore, contrary to Niaz's conclusion that the acceptance of Piaget's epistemic subject will facilitate the development of cognitive theories with greater explanatory power, the conclusion is reached that Piaget's epistemic subject is dead and that continued acceptance of this aspect of Piagetian theory would be counterproductive.

  9. Leatherback sea turtle age and growth

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study involves analysis of skeletal growth marks in scleral ossicle bones of 33 leatherback sea turtles stranded dead along the Atlantic and Gulf of Mexico US...

  10. Brackish to hypersaline lake dolostones of the Mississippian

    Science.gov (United States)

    Bennett, Carys; Kearsey, Timothy; Davies, Sarah; Millward, David; Marshall, John

    2016-04-01

    , and 9% of all dolostone beds in the Norham Core are pedogenically altered. The isotopic composition of dolomite beds is δ18O -3.6‰ to -1.7‰ and δ13C -2.6‰ to 1.6‰ which is consistent with a brackish as opposed to marine origin. The dolostones are categorised by their sedimentary composition: Facies 1: Cemented siltstone and sandstone; Facies 2: Homogeneous micrite to micro-crystaline dolomite, within a clay matrix; Facies 3: Bedded dolomite and siltstone; Facies 4: Mixed calcite and dolomite; Facies 5: Dolomite with gypsum and anhydrite. Formation processes are diverse, and include diagenetic cementation (Facies 1), deposition in saline (brackish) lakes (Facies 2), deposition in saline lakes with clastic sediment input (Facies 3), lagoonal to shallow-marine carbonate deposition (Facies 4), and hypersaline lake to sabkha environments (Facies 5). 60% of the beds are facies 2 or 3 and their sedimentology, fauna, ichnofauna and isotopic composition indicate a brackish-water origin. Other Mississippian dolostones from around the world also contain a fairly restricted fauna and have been interpreted as brackish water deposits. The mechanism of dolomite formation under these conditions is discussed. These dolostones provided extensive coastal lakes that may have been an important habitat for tetrapods and other transitional groups during the Mississippian.

  11. More Dead than Dead: Perceptions of Persons in the Persistent Vegetative State

    Science.gov (United States)

    Gray, Kurt; Knickman, T. Anne; Wegner, Daniel M.

    2011-01-01

    Patients in persistent vegetative state (PVS) may be biologically alive, but these experiments indicate that people see PVS as a state curiously more dead than dead. Experiment 1 found that PVS patients were perceived to have less mental capacity than the dead. Experiment 2 explained this effect as an outgrowth of afterlife beliefs, and the…

  12. 42 CFR 71.55 - Dead bodies.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Dead bodies. 71.55 Section 71.55 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES QUARANTINE, INSPECTION, LICENSING FOREIGN QUARANTINE Importations § 71.55 Dead bodies. The remains of a person who died of a communicable disease...

  13. 49 CFR 236.798 - Section, dead.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Section, dead. 236.798 Section 236.798 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Section, dead. A section of track, either within a track circuit or between two track circuits, the rails...

  14. Unexpected Diversity and Complexity of the Guerrero Negro Hypersaline Microbial Mat

    OpenAIRE

    Ruth E. Ley; Harris, J. Kirk; Wilcox, Joshua; Spear, John R.; Miller, Scott R.; Bebout, Brad M.; Maresca, Julia A.; Bryant, Donald A.; Sogin, Mitchell L.; Norman R. Pace

    2006-01-01

    We applied nucleic acid-based molecular methods, combined with estimates of biomass (ATP), pigments, and microelectrode measurements of chemical gradients, to map microbial diversity vertically on a millimeter scale in a hypersaline microbial mat from Guerrero Negro, Baja California Sur, Mexico. To identify the constituents of the mat, small-subunit rRNA genes were amplified by PCR from community genomic DNA extracted from layers, cloned, and sequenced. Bacteria dominated the mat and displaye...

  15. Microbial Diversity of the Hypersaline Sidi Ameur and Himalatt Salt Lakes of the Algerian Sahara

    OpenAIRE

    Boutaiba, Saad; Hacene, Hocine; Bidle, Kelly A.; Maupin-Furlow, Julie A.

    2011-01-01

    Microbial populations within hypersaline lakes often exhibit high activities of photosynthesis, dissimilatory sulphate reduction and other processes and, thus, can have profound impacts on biogeochemical cycles of carbon, nitrogen, sulphur and other important elements within arid lands. To further understand these types of ecosystems, the physicochemical and biological properties of Sidi Ameur and Himalatt Salt Lakes in the Algerian Sahara were examined and compared. Both lakes were relativel...

  16. Organismal and spatial partitioning of energy and macronutrient transformations within a hypersaline mat

    Energy Technology Data Exchange (ETDEWEB)

    Mobberley, Jennifer M.; Lindemann, Stephen R.; Bernstein, Hans C.; Moran, James J.; Renslow, Ryan S.; Babauta, Jerome; Hu, Dehong; Beyenal, Haluk; Nelson, William C.

    2017-03-21

    Phototrophic mat communities are model ecosystems for studying energy cycling and elemental transformations because complete biogeochemical cycles occur over millimeter-to-centimeter scales. Characterization of energy and nutrient capture within hypersaline phototrophic mats has focused on specific processes and organisms, however little is known about community-wide distribution of and linkages between these processes. To investigate energy and macronutrient capture and flow through a structured community, the spatial and organismal distribution of metabolic functions within a compact hypersaline mat community from Hot Lake have been broadly elucidated through species-resolved metagenomics and geochemical, microbial diversity, and metabolic gradient measurements. Draft reconstructed genomes of abundant organisms revealed three dominant cyanobacterial populations differentially distributed across the top layers of the mat suggesting niche separation along light and oxygen gradients. Many organisms contained diverse functional profiles, allowing for metabolic response to changing conditions within the mat. Organisms with partial nitrogen and sulfur metabolisms were widespread indicating dependence upon metabolite exchange. In addition, changes in community spatial structure were observed over the diel. These results indicate that organisms within the mat community have adapted to the temporally dynamic environmental gradients in this hypersaline mat through metabolic flexibility and fluid syntrophic interactions, including shifts in spatial arrangements.

  17. The density-driven circulation of the coastal hypersaline system of the Great Barrier Reef, Australia.

    Science.gov (United States)

    Salamena, Gerry G; Martins, Flávio; Ridd, Peter V

    2016-04-15

    The coastal hypersaline system of the Great Barrier Reef (GBR) in the dry season, was investigated for the first time using a 3D baroclinic model. In the shallow coastal embayments, salinity increases to c.a. 1‰ above typical offshore salinity (~35.4‰). This salinity increase is due to high evaporation rates and negligible freshwater input. The hypersalinity drifts longshore north-westward due to south-easterly trade winds and may eventually pass capes or headlands, e.g. Cape Cleveland, where the water is considerably deeper (c.a. 15m). Here, a pronounced thermohaline circulation is predicted to occur which flushes the hypersalinity offshore at velocities of up to 0.08m/s. Flushing time of the coastal embayments is around 2-3weeks. During the dry season early summer, the thermohaline circulation reduces and therefore, flushing times are predicted to be slight longer due to the reduced onshore-offshore density gradient compared to that in the dry season winter period. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Microbial Diversity in a Hypersaline Sulfate Lake: A Terrestrial Analog of Ancient Mars

    Directory of Open Access Journals (Sweden)

    Alexandra Pontefract

    2017-09-01

    Full Text Available Life can persist under severe osmotic stress and low water activity in hypersaline environments. On Mars, evidence for the past presence of saline bodies of water is prevalent and resulted in the widespread deposition of sulfate and chloride salts. Here we investigate Spotted Lake (British Columbia, Canada, a hypersaline lake with extreme (>3 M levels of sulfate salts as an exemplar of the conditions thought to be associated with ancient Mars. We provide the first characterization of microbial structure in Spotted Lake sediments through metagenomic sequencing, and report a bacteria-dominated community with abundant Proteobacteria, Firmicutes, and Bacteroidetes, as well as diverse extremophiles. Microbial abundance and functional comparisons reveal similarities to Ace Lake, a meromictic Antarctic lake with anoxic and sulfidic bottom waters. Our analysis suggests that hypersaline-associated species occupy niches characterized foremost by differential abundance of Archaea, uncharacterized Bacteria, and Cyanobacteria. Potential biosignatures in this environment are discussed, specifically the likelihood of a strong sulfur isotopic fractionation record within the sediments due to the presence of sulfate reducing bacteria. With its high sulfate levels and seasonal freeze-thaw cycles, Spotted Lake is an analog for ancient paleolakes on Mars in which sulfate salt deposits may have offered periodically habitable environments, and could have concentrated and preserved organic materials or their biomarkers over geologic time.

  19. Spatial and temporal variability in a stratified hypersaline microbial mat community.

    Science.gov (United States)

    Dillon, Jesse G; Miller, Scott; Bebout, Brad; Hullar, Meredith; Pinel, Nicolás; Stahl, David A

    2009-04-01

    Hypersaline microbial mat communities have recently been shown to be more diverse than once thought. The variability in community composition of hypersaline mats, both in terms of spatial and temporal dimensions, is still poorly understood. Because this information is essential to understanding the complex biotic and abiotic interactions within these communities, terminal restriction fragment analysis and 16S rRNA gene sequencing were used to characterize the near-surface community of a hypersaline microbial mat in Guerrero Negro, Mexico. Core samples were analyzed to assay community variability over large regional scales (centimeter to kilometer) and to track depth-related changes in population distribution at 250-microm intervals over a diel period. Significant changes in total species diversity were observed at increasing distances across the mat surface; however, key species (e.g. Microcoleus sp.) were identified throughout the mat. The vertical position and abundance of >50% of the 60 peaks detected varied dramatically over a diel cycle, including Beggiatoa sp., cyanobacteria, Chloroflexus sp., Halochromatium sp., Bacteroidetes sp. and several as-yet-identified bacteria. Many of these migrations correlated strongly with diel changes in redox conditions within the mat, contributing to strong day-night community structure differences.

  20. Microbial community structure and diversity within hypersaline Keke Salt Lake environments.

    Science.gov (United States)

    Han, Rui; Zhang, Xin; Liu, Jing; Long, Qifu; Chen, Laisheng; Liu, Deli; Zhu, Derui

    2017-11-01

    Keke Salt Lake is located in the Qaidamu Basin of China. It is a unique magnesium sulfate-subtype hypersaline lake that exhibits a halite domain ecosystem, yet its microbial diversity has remained unstudied. Here, the microbial community structure and diversity was investigated via high-throughput sequencing of the V3-V5 regions of 16S rRNA genes. A high diversity of operational taxonomic units was detected for Bacteria and Archaea (734 and 747, respectively), comprising 21 phyla, 43 classes, and 201 genera of Bacteria and 4 phyla, 4 classes, and 39 genera of Archaea. Salt-saturated samples were dominated by the bacterial genera Bacillus (51.52%-58.35% relative abundance), Lactococcus (9.52%-10.51%), and Oceanobacillus (8.82%-9.88%) within the Firmicutes phylum (74.81%-80.99%), contrasting with other hypersaline lakes. The dominant Archaea belonged to the Halobacteriaceae family, and in particular, the genera (with an abundance of >10% of communities) Halonotius, Halorubellus, Halapricum, Halorubrum, and Natronomonas. Additionally, we report the presence of Nanohaloarchaeota and Woesearchaeota in Qinghai-Tibet Plateau lakes, which has not been previously documented. Total salinity (especially Mg 2+ , Cl - , Na + , and K + ) mostly correlated with taxonomic distribution across samples. These results expand our understanding of microbial resource utilization within hypersaline lakes and the potential adaptations of dominant microorganisms that allow them to inhabit such environments.

  1. Trophic ecology and food consumption of fishes in a hypersaline tropical lagoon.

    Science.gov (United States)

    Almeida-Silva, P H; Tubino, R A; Zambrano, L C; Hunder, D A; Garritano, S R; Monteiro-Neto, C

    2015-06-01

    This study evaluated the trophic ecology (diet composition, trophic strategy, similarities and overlap between species, feeding period and food consumption) of six benthivorous fish species in Araruama Lagoon, the largest hypersaline tropical lagoon on the east coast of South America, with an area of 210 km(2) and an average salinity of 52. The burrfish Chilomycterus spinosus fed on Anomalocardia flexuosa shell deposits, ingesting associated fauna. The caitipa mojarra Diapterus rhombeus differed from all other species, having not only the highest proportions of algae and Nematoda, but also feeding on polychaete tentacles. The two mojarras Eucinostomus spp. showed similar trophic strategies, feeding mostly on Polychaeta. The corocoro grunt Orthopristis ruber also fed mainly on Polychaeta, but differed from Eucinostomus spp. in secondary items. The whitemouth croacker Micropogonias furnieri fed mainly on small Crustacea at night, showing a high number of secondary prey items with low frequencies and high prey-specific abundance. The daily food consumption (g food g(-1) fish mass) for Eucinostomus argenteus was 0·012 and was 0·031 and 0·027 for M. furnieri in two different sampling events. The diet similarities between Araruama Lagoon and other brackish and marine environments indicate that hypersalinity is not a predominant factor shaping the trophic ecology of fishes in this lagoon. The stability of hypersaline conditions, without a pronounced gradient, may explain the presence of several euryhaline fishes and invertebrates well adapted to this condition, resulting in a complex food web. © 2015 The Fisheries Society of the British Isles.

  2. [New isolation methods and phylogenetic diversity of actinobacteria from hypersaline beach in Aksu].

    Science.gov (United States)

    Zhang, Yao; Xia, Zhanfeng; Cao, Xinbo; Li, Jun; Zhang, Lili

    2013-08-04

    We explored 4 new methods to improve the isolation of actinobacterial resources from high salt areas. Optimized media based on 4 new strategies were used for isolating actinobacteria from hypersaline beaches. Glycerin-arginine, trehalose-creatine, glycerol-asparticacid, mannitol-casein, casein-mannitol, mannitol-alanine, chitosan-asparagineand GAUZE' No. 1 were used as basic media. New isolation strategy includes 4 methods: ten-fold dilution culture, simulation of the original environment, actinobacterial culture guided by uncultured molecular technology detected, and reference of actinobacterial media for brackish marine environment. The 16S rRNA genes of the isolates were amplified with bacterial universal primers. The results of 16S rRNA gene sequences were compared with sequences obtained from GenBank databases. We constructed phylogenetic tree with the neighbor-joining method. No actinobacterial strains were isolated by 8 media of control group, while 403 strains were isolated by new strategies. The isolates by new methods were members of 14 genera (Streptomyces, Streptomonospora, Saccharomonospora, Plantactinospora, Nocardia, Amycolatopsis, Glycomyces, Micromonospora, Nocardiopsis, Isoptericola, Nonomuraea, Thermobifida, Actinopolyspora, Actinomadura) of 10 families in 8 suborders. The most abundant and diverse isolates were the two suborders of Streptomycineae (69.96%) and Streptosporangineaesuborder (9.68%) within the phylum Actinobacteria, including 9 potential novel species. New isolation methods significantly improved the actinobacterial culturability of hypersaline areas, and obtained many potential novel species, which provided a new and more effective way to isolate actinobacteria resources in hypersaline environments.

  3. Hypersaline waters - a potential source of foodborne toxigenic aspergilli and penicillia.

    Science.gov (United States)

    Butinar, Lorena; Frisvad, Jens C; Gunde-Cimerman, Nina

    2011-07-01

    Previous studies of hypersaline environments have revealed the dominant presence of melanized yeast-like fungi and related Cladosporium spp. In this study, we focused on the genera Aspergillus and Penicillium and their teleomorphic forms. From oligotrophic and eutrophic hypersaline waters around the world, 60 different species were identified, according to their morphological characteristics and extrolite profiles. For the confirmation of five new species, additionally, sequence analysis of the internal transcribed spacer region, the partial large subunit-rDNA and the partial β-tubulin gene was performed. The species Aspergillus niger, Eurotium amstelodami and Penicillium chrysogenum were detected with the highest frequencies at all of the sampled sites; thus, they represent the pan-global stable mycobiota in hypersaline environments. Possible candidates were also Aspergillus sydowii and Eurotium herbariorum, as they were quite evenly distributed among the sampled sites, and Aspergillus candidus, which was abundant, but more locally distributed. These species and their byproducts can accumulate downstream following evaporation of brine, and they can become entrapped in the salt crystals. Consequently, marine salt used for consumption can be a potential source of food-borne fungi and their byproducts. For example, ochratoxin-A-producing species Penicillium nordicum was recovered from brine, salt and salted meat products. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  4. A deep sea community at the Kebrit brine pool in the Red Sea

    KAUST Repository

    Vestheim, Hege

    2015-02-26

    Approximately 25 deep sea brine pools occur along the mid axis of the Red Sea. These hypersaline, anoxic, and acidic environments have previously been reported to host diverse microbial communities. We visited the Kebrit brine pool in April 2013 and found macrofauna present just above the brine–seawater interface (~1465 m). In particular, inactive sulfur chimneys had associated epifauna of sea anemones, sabellid type polychaetes, and hydroids, and infauna consisting of capitellid polychaetes, gastropods of the genus Laeviphitus (fam. Elachisinidae), and top snails of the family Cocculinidae. The deep Red Sea generally is regarded as extremely poor in benthos. We hypothesize that the periphery along the Kebrit holds increased biomass and biodiversity that are sustained by prokaryotes associated with the brine pool or co-occurring seeps.

  5. De Plein Fouet: Is Strategy Dead?

    Science.gov (United States)

    2015-06-01

    10 | Air & Space Power Journal De Plein Fouet: Is Strategy Dead ? Robert Cardillo Richard Szafranski Disclaimer: The views and opinions expressed or...of French Artillery Instructors in the U.S. Army.”1 Let’s fire directly at the idea of strategy. The hypothesis is that strategy is dead , and that’s...TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE De Plein Fouet: Is Strategy Dead ? 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  6. Extreme Heat in Southwest a Deadly Threat

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_166797.html Extreme Heat in Southwest a Deadly Threat Here's how to ... t take off in Phoenix on Tuesday, the heat wave scorching the Southwest for the next week ...

  7. Surviving Sepsis: Taming a Deadly Immune Response

    Science.gov (United States)

    ... Issues Subscribe August 2014 Print this issue Surviving Sepsis Taming a Deadly Immune Response En español Send ... Mouth? Looking at Lupus Wise Choices Signs of Sepsis Sepsis can be hard to spot, because its ...

  8. Dead cell phagocytosis and innate immune checkpoint

    Science.gov (United States)

    Yoon, Kyoung Wan

    2017-01-01

    The human body loses several billions of cells daily. When cells die in vivo, the corpse of each dead cell is immediately cleared. Specifically, dead cells are efficiently recognized and cleared by multiple types of neighboring phagocytes. Early research on cell death focused more on molecular mechanisms of cell death regulation while the cellular corpses were merely considered cellular debris. However, it has come to light that various biological stimuli following cell death are important for immune regulation. Clearance of normal dead cells occurs silently in immune tolerance. Exogenous or mutated antigens of malignant or infected cells can initiate adaptive immunity, thereby inducing immunogenicity by adjuvant signals. Several pathogens and cancer cells have strategies to limit the adjuvant signals and escape immune surveillance. In this review, we present an overview of the mechanisms of dead cell clearance and its immune regulations. PMID:28768566

  9. The dead donor rule: a defense.

    Science.gov (United States)

    Birch, Samuel C M

    2013-08-01

    Miller, Truog, and Brock have recently argued that the "dead donor rule," the requirement that donors be determined to be dead before vital organs are procured for transplantation, cannot withstand ethical scrutiny. In their view, the dead donor rule is inconsistent with existing life-saving practices of organ transplantation, lacks a cogent ethical rationale, and is not necessary for maintenance of public trust in organ transplantation. In this paper, the second of these claims will be evaluated. (The first and third are not addressed.) The claim that the dead donor rule lacks a cogent ethical rationale will be shown to be an expression of the contemporary rejection of the moral significance of the traditional distinction between killing and allowing to die. The moral significance of this traditional distinction, and the associated norm that doctors should not kill their patients, will be defended, and this critique of it shown to be unsuccessful.

  10. Fentanyl Patch Can Be Deadly to Children

    Science.gov (United States)

    ... Products For Consumers Home For Consumers Consumer Updates Fentanyl Patch Can Be Deadly to Children Share Tweet ... from accidental exposure to a skin patch containing fentanyl, a powerful pain reliever. As a result of ...

  11. Could 'Safer' Filtered Cigarettes Be More Deadly?

    Science.gov (United States)

    ... gov/news/fullstory_165825.html Could 'Safer' Filtered Cigarettes Be More Deadly? New report suggests they're ... 2017 MONDAY, May 22, 2017 (HealthDay News) -- Filtered cigarettes might be even more lethal than unfiltered ones, ...

  12. Dead pixel replacement in LWIR microgrid polarimeters.

    Science.gov (United States)

    Ratliff, Bradley M; Tyo, J Scott; Boger, James K; Black, Wiley T; Bowers, David L; Fetrow, Matthew P

    2007-06-11

    LWIR imaging arrays are often affected by nonresponsive pixels, or "dead pixels." These dead pixels can severely degrade the quality of imagery and often have to be replaced before subsequent image processing and display of the imagery data. For LWIR arrays that are integrated with arrays of micropolarizers, the problem of dead pixels is amplified. Conventional dead pixel replacement (DPR) strategies cannot be employed since neighboring pixels are of different polarizations. In this paper we present two DPR schemes. The first is a modified nearest-neighbor replacement method. The second is a method based on redundancy in the polarization measurements.We find that the redundancy-based DPR scheme provides an order-of-magnitude better performance for typical LWIR polarimetric data.

  13. Exploring Archaeal Communities And Genomes Across Five Deep-Sea Brine Lakes Of The Red Sea With A Focus On Methanogens

    KAUST Repository

    Guan, Yue

    2015-12-15

    The deep-sea hypersaline lakes in the Red Sea are among the most challenging, extreme, and unusual environments on the planet Earth. Despite their harshness to life, they are inhabited by diverse and novel members of prokaryotes. Methanogenesis was proposed as one of the main metabolic pathways that drive microbial colonization in similar habitats. However, not much is known about the identities of the methane-producing microbes in the Red Sea, let alone the way in which they could adapt to such poly extreme environments. Combining a range of microbial community assessment, cultivation and omics (genomics, transcriptomics, and single amplified genomics) approaches, this dissertation seeks to fill these gaps in our knowledge by studying archaeal composition, particularly methanogens, their genomic capacities and transcriptomic characteristics in order to elucidate their diversity, function, and adaptation to the deep-sea brines of the Red Sea. Although typical methanogens are not abundant in the samples collected from brine pool habitats of the Red Sea, the pilot cultivation experiment has revealed novel halophilic methanogenic species of the domain Archaea. Their physiological traits as well as their genomic and transcriptomic features unveil an interesting genetic and functional adaptive capacity that allows them to thrive in the unique deep-sea hypersaline environments in the Red Sea.

  14. Development of a halotolerant community in the St. Lucia Estuary (South Africa) during a hypersaline phase.

    Science.gov (United States)

    Carrasco, Nicola K; Perissinotto, Renzo

    2012-01-01

    The St. Lucia Estuary, Africa's largest estuarine lake, is currently experiencing unprecedented freshwater deprivation which has resulted in a northward gradient of drought effects, with hypersaline conditions in its northern lakes. This study documents the changes that occurred in the biotic communities at False Bay from May 2010 to June 2011, in order to better understand ecosystem functioning in hypersaline habitats. Few zooplankton taxa were able to withstand the harsh environmental conditions during 2010. These were the flatworm Macrostomum sp., the harpacticoid copepod Cletocamptus confluens, the cyclopoid copepod Apocyclops cf. dengizicus and the ciliate Fabrea cf. salina. In addition to their exceptional salinity tolerance, they were involved in a remarkably simple food web. In June 2009, a bloom of an orange-pigmented cyanobacterium (Cyanothece sp.) was recorded in False Bay and persisted uninterruptedly for 18 months. Stable isotope analysis suggests that this cyanobacterium was the main prey item of F. cf. salina. This ciliate was then consumed by A. cf. dengizicus, which in turn was presumably consumed by flamingos as they flocked in the area when the copepods attained swarming densities. On the shore, cyanobacteria mats contributed to a population explosion of the staphylinid beetle Bledius pilicollis. Although zooplankton disappeared once salinities exceeded 130, many taxa are capable of producing spores or resting cysts to bridge harsh periods. The hypersaline community was disrupted by heavy summer rains in 2011, which alleviated drought conditions and resulted in a sharp increase in zooplankton stock and diversity. Despite the current freshwater deprivation crisis, the False Bay region has shown to be resilient, harboring a unique biodiversity with species that are capable of enduring harsh environmental conditions. However, further freshwater deprivation may extend beyond the physiological thresholds of this community, as well as other unique

  15. Development of a halotolerant community in the St. Lucia Estuary (South Africa during a hypersaline phase.

    Directory of Open Access Journals (Sweden)

    Nicola K Carrasco

    Full Text Available The St. Lucia Estuary, Africa's largest estuarine lake, is currently experiencing unprecedented freshwater deprivation which has resulted in a northward gradient of drought effects, with hypersaline conditions in its northern lakes.This study documents the changes that occurred in the biotic communities at False Bay from May 2010 to June 2011, in order to better understand ecosystem functioning in hypersaline habitats. Few zooplankton taxa were able to withstand the harsh environmental conditions during 2010. These were the flatworm Macrostomum sp., the harpacticoid copepod Cletocamptus confluens, the cyclopoid copepod Apocyclops cf. dengizicus and the ciliate Fabrea cf. salina. In addition to their exceptional salinity tolerance, they were involved in a remarkably simple food web. In June 2009, a bloom of an orange-pigmented cyanobacterium (Cyanothece sp. was recorded in False Bay and persisted uninterruptedly for 18 months. Stable isotope analysis suggests that this cyanobacterium was the main prey item of F. cf. salina. This ciliate was then consumed by A. cf. dengizicus, which in turn was presumably consumed by flamingos as they flocked in the area when the copepods attained swarming densities. On the shore, cyanobacteria mats contributed to a population explosion of the staphylinid beetle Bledius pilicollis. Although zooplankton disappeared once salinities exceeded 130, many taxa are capable of producing spores or resting cysts to bridge harsh periods. The hypersaline community was disrupted by heavy summer rains in 2011, which alleviated drought conditions and resulted in a sharp increase in zooplankton stock and diversity.Despite the current freshwater deprivation crisis, the False Bay region has shown to be resilient, harboring a unique biodiversity with species that are capable of enduring harsh environmental conditions. However, further freshwater deprivation may extend beyond the physiological thresholds of this community, as well as

  16. Bacterial community response to petroleum hydrocarbon amendments in freshwater, marine, and hypersaline water-containing microcosms.

    Science.gov (United States)

    Jurelevicius, Diogo; Alvarez, Vanessa Marques; Marques, Joana Montezano; de Sousa Lima, Laryssa Ribeiro Fonseca; Dias, Felipe de Almeida; Seldin, Lucy

    2013-10-01

    Hydrocarbon-degrading bacterial communities from freshwater, marine, and hypersaline Brazilian aquatic ecosystems (with water salinities corresponding to 0.2%, 4%, and 5%, respectively) were enriched with different hydrocarbons (heptadecane, naphthalene, or crude oil). Changes within the different microcosms of bacterial communities were analyzed using cultivation approaches and molecular methods (DNA and RNA extraction, followed by genetic fingerprinting and analyses of clone libraries based on the 16S rRNA-coding gene). A redundancy analysis (RDA) of the genetic fingerprint data and a principal component analysis (PCA) of the clone libraries revealed hydrocarbon-enriched bacterial communities specific for each ecosystem studied. However, within the same ecosystem, different bacterial communities were selected according to the petroleum hydrocarbon used. In general, the results demonstrated that Acinetobacter and Cloacibacterium were the dominant genera in freshwater microcosms; the Oceanospirillales order and the Marinobacter, Pseudomonas, and Cycloclasticus genera predominated in marine microcosms; and the Oceanospirillales order and the Marinobacter genus were selected in the different hydrocarbon-containing microcosms in hypersaline water. Determination of total petroleum hydrocarbons (TPHs) in all microcosms after 32 days of incubation showed a decrease in the hydrocarbon concentration compared to that for the controls. A total of 50 (41.3%) isolates from the different hydrocarbon-contaminated microcosms were associated with the dominant operational taxonomic units (OTUs) obtained from the clone libraries, and their growth in the hydrocarbon contaminating the microcosm from which they were isolated as the sole carbon source was observed. These data provide insight into the general response of bacterial communities from freshwater, marine, and hypersaline aquatic ecosystems to petroleum hydrocarbon contamination.

  17. Linking Archaeal Molecular Diversity and Lipid Biomarker Composition in a Hypersaline Microbial Mat Community

    Science.gov (United States)

    Jahnke, Linda; Orphan, Victoria; Turk, Kendra; Embaye, Tsegereda; Kubo, Mike; Summons, Roger

    2005-01-01

    Lipid biomarkers for discrete microbial groups are a valuable tool for establishing links to ancient microbial ecosystems. Lipid biomarkers can establish organism source and function in contemporary microbial ecosystems (membrane lipids) and by analogy, potential relevance to the fossilized carbon skeletons (geolipids) extracted from ancient sedimentary rock. The Mars Exploration Rovers have provided clear evidence for an early wet Mars and the presence of hypersaline evaporitic basins. Ongoing work on an early Earth analog, the hypersaline benthic mats in Guerrero Negro, Baja California Sur, may provide clues to what may have evolved and flourished on an early wet Mars, if only for a short period. Cyanobacterial mats are a pertinent early Earth analog for consideration of evolutionary and microbial processes within the aerobic photosynthetic and adjacent anoxic layers. Fluctuations in physio-chemical parameters associated with spatial and temporal scales are expressed through vast microbial metabolic diversity. Our recent work hopes to establish the dynamic of archaeal diversity, particularly as it relates to methane production in this high sulfate environment, through the use of lipid biomarker and phylogenetic analyses. Archaeal 16s rRNA and mcrA gene assemblages, demonstrated distinct spatial separation over the 130 mm core of at least three distinct genera within the order Methanosarcinales, as well as an abundance of uncultured members of the Thermoplasmales and Crenarchaeota. Ether-bound lipid analysis identified abundant 0-alkyl and 0-isopranyl chains throughout the core, and the presence of sn-2 hydroxyarchaeol, a biomarker for methylotrophic methanogens. A unique ether isoprenoid chain, a C30:1 , possibly related to the geolipid squalane, a paleobiomarker associated with hypersaline environments, was most abundant within the oxic-anoxic transition zone.

  18. Metagenome of a versatile chemolithoautotroph from expanding oceanic dead zones.

    Science.gov (United States)

    Walsh, David A; Zaikova, Elena; Howes, Charles G; Song, Young C; Wright, Jody J; Tringe, Susannah G; Tortell, Philippe D; Hallam, Steven J

    2009-10-23

    Oxygen minimum zones, also known as oceanic "dead zones," are widespread oceanographic features currently expanding because of global warming. Although inhospitable to metazoan life, they support a cryptic microbiota whose metabolic activities affect nutrient and trace gas cycling within the global ocean. Here, we report metagenomic analyses of a ubiquitous and abundant but uncultivated oxygen minimum zone microbe (SUP05) related to chemoautotrophic gill symbionts of deep-sea clams and mussels. The SUP05 metagenome harbors a versatile repertoire of genes mediating autotrophic carbon assimilation, sulfur oxidation, and nitrate respiration responsive to a wide range of water-column redox states. Our analysis provides a genomic foundation for understanding the ecological and biogeochemical role of pelagic SUP05 in oxygen-deficient oceanic waters and its potential sensitivity to environmental changes.

  19. Metagenome of a Versatile Chemolithoautotroph from Expanding Oceanic Dead Zones

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, David A.; Zaikova, Elena; Howes, Charles L.; Song, Young; Wright, Jody; Tringe, Susannah G.; Tortell, Philippe D.; Hallam, Steven J.

    2009-07-15

    Oxygen minimum zones (OMZs), also known as oceanic"dead zones", are widespread oceanographic features currently expanding due to global warming and coastal eutrophication. Although inhospitable to metazoan life, OMZs support a thriving but cryptic microbiota whose combined metabolic activity is intimately connected to nutrient and trace gas cycling within the global ocean. Here we report time-resolved metagenomic analyses of a ubiquitous and abundant but uncultivated OMZ microbe (SUP05) closely related to chemoautotrophic gill symbionts of deep-sea clams and mussels. The SUP05 metagenome harbors a versatile repertoire of genes mediating autotrophic carbon assimilation, sulfur-oxidation and nitrate respiration responsive to a wide range of water column redox states. Thus, SUP05 plays integral roles in shaping nutrient and energy flow within oxygen-deficient oceanic waters via carbon sequestration, sulfide detoxification and biological nitrogen loss with important implications for marine productivity and atmospheric greenhouse control.

  20. Gulf of Mexico Kemps ridley sea turtle age and growth

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study involves analysis of skeletal growth marks in humerus bones of 340 Kemps ridley sea turtles stranded dead along the Gulf of Mexico US coast (hatchling to...

  1. Summary of bacteria found in captive sea turtles 2002-Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The database contains a summary of bacteria which have been isolated in sea turtles dead and alive at the NOAA Galveston Laboratory and is based on reports received...

  2. Influenza A virus H10N7 detected in dead harbor seals (Phoca vitulina) at several locations in Denmark 2014

    DEFF Research Database (Denmark)

    Hjulsager, Charlotte Kristiane; Krog, Jesper Schak; Hansen, Mette Sif

    as many waterfowl species and are therefore potentially exposed to AIV. Outbreaks of AI in seals have been described in North America and Asia but prior to 2014 never in Europe. In 2014 massive deaths of harbor seals (Phoca vitulina) were reported in Northern Europe. In Denmark, harbor seals were...... initially found dead on the Danish island Anholt in Kattegat, which is the sea surrounded by Denmark, Norway and Sweden. Between June and August, 152 harbor seals were found dead. Four seals were submitted to the National Veterinary Institute in Dennmark and diagnosed with severe pneumonia. Influenza...... A virus of the subtype H10N7 was detected in two out of four seals. Subsequently IAV was detected in dead harbor seals at several locations in Denmark. The IAV outbreak appeared to move with time to the west through the Limfjord to the North Sea and further down south along the west coast of Jutland...

  3. Virtually Dead: Digital Public Mortuary Archaeology

    Directory of Open Access Journals (Sweden)

    Howard Williams

    2015-12-01

    Full Text Available Over recent decades, the ethics, politics and public engagements of mortuary archaeology have received sustained scrutiny, including how we handle, write about and display the archaeological dead. Yet the burgeoning use of digital media to engage different audiences in the archaeology of death and burial have so far escaped attention. This article explores categories and strategies by which digital media create virtual communities engaging with mortuary archaeology. Considering digital public mortuary archaeology (DPMA as a distinctive theme linking archaeology, mortality and material culture, we discuss blogs, vlogs and Twitter as case studies to illustrate the variety of strategies by which digital media can promote, educate and engage public audiences with archaeological projects and research relating to death and the dead in the human past. The article then explores a selection of key critical concerns regarding how the digital dead are currently portrayed, identifying the need for further investigation and critical reflection on DPMA’s aims, objectives and aspired outcomes.

  4. Dead Zone Accretion Flows in Protostellar Disks

    Science.gov (United States)

    Turner, Neal; Sano, T.

    2008-01-01

    Planets form inside protostellar disks in a dead zone where the electrical resistivity of the gas is too high for magnetic forces to drive turbulence. We show that much of the dead zone nevertheless is active and flows toward the star while smooth, large-scale magnetic fields transfer the orbital angular momentum radially outward. Stellar X-ray and radionuclide ionization sustain a weak coupling of the dead zone gas to the magnetic fields, despite the rapid recombination of free charges on dust grains. Net radial magnetic fields are generated in the magnetorotational turbulence in the electrically conducting top and bottom surface layers of the disk, and reach the midplane by ohmic diffusion. A toroidal component to the fields is produced near the midplane by the orbital shear. The process is similar to the magnetization of the solar tachocline. The result is a laminar, magnetically driven accretion flow in the region where the planets form.

  5. Halo(natronoarchaea isolated from hypersaline lakes utilize cellulose and chitin as growth substrates

    Directory of Open Access Journals (Sweden)

    Dimitry Y Sorokin

    2015-09-01

    Full Text Available Until recently, extremely halophilic euryarchaeota were considered mostly as aerobic heterotrophs utilizing simple organic compounds as growth substrates. Almost nothing is known on the ability of these prokaryotes to utilize complex polysaccharides as cellulose, xylan and chitin. Although few haloarchaeal cellulases and chitinases were recently characterized, the analysis of currently available haloarchaeal genomes deciphered numerous genes encoding glycosidases (GHs of various families including endoglucanases and chitinases. However, all these haloarchaea were isolated and cultivated on simple substrates and their ability to grow on polysaccharides in situ or in vitro is unknown. This study examines several halo(natronoarchaeal strains from geographically distant hypersaline lakes for the ability to grow on insoluble polymers as a sole growth substrate in salt-saturated mineral media. Some of them belonged to known taxa, while other represented novel phylogenetic lineages within the class Halobacteria. All isolates produced extracellular extremely salt tolerant cellulases or chitinases, either cell-free or cell-bound. Obtained results demonstrate a presence of diverse population of haloarchaeal cellulo/chitinotrophs in hypersaline habitats indicating that euryarchaea participate in aerobic mineralization of recalcitrant organic polymers in salt-saturated environments.

  6. Leaf Spectral Reflectance Shows Thalassia testudinum Seedlings More Sensitive to Hypersalinity than Hyposalinity.

    Science.gov (United States)

    Durako, Michael J; Howarth, Jacqueline F

    2017-01-01

    Thalassia testudinum (turtle grass) is the dominant and climax-successional seagrass species in the subtropical/tropical Atlantic and Caribbean region. Two die-offs of T. testudinum in Florida Bay, United States have raised concerns regarding the resilience of this species to environmental disturbances. Seedlings are important in recovery of T. testudinum, following disturbance events. Leaf spectral reflectance [R(λ)] was measured in T. testudinum seedlings exposed for 2 weeks to three salinities (20, 35, and 50) and two light levels (full sun and 50-70% light reduction) in experimental mesocosms. Multivariate analyses indicated that hypersalinity had a greater effect on spectral reflectance than hyposalinity or light reduction. There was an increase in variability and flattening of reflectance spectra at the highest salinity. All three salinity treatments had distinct reflectance spectra across green wavelengths (530-580 nm), with additional discrimination between 20 versus 50 and 35 versus 50 treatments across red wavelengths (630-690 nm). Red:Green reflectance ratios were highest and photochemical reflective index values were lowest for the salinity 50 treatment, but were not significantly different between the salinity 20 and 35 treatments. The changes in the R(λ) spectra for the salinity 50 seedlings were consistent with previously observed reductions in leaf pigments and maximum photochemical efficiency of photosystem II. These observations indicate that leaf spectral reflectance is a sensitive indicator of plant stress in T. testudinum seedlings and that seedlings are more sensitive to short-term exposures to hypersalinity than hyposalinity.

  7. Removal performance and microbial communities in a sequencing batch reactor treating hypersaline phenol-laden wastewater.

    Science.gov (United States)

    Jiang, Yu; Wei, Li; Zhang, Huining; Yang, Kai; Wang, Hongyu

    2016-10-01

    Hypersaline phenol-rich wastewater is hard to be treated by traditional biological systems. In this work, a sequencing batch reactor was used to remove phenol from hypersaline wastewater. The removal performance was evaluated in response to the variations of operating parameters and the microbial diversity was investigated by 454 pyrosequencing. The results showed that the bioreactor had high removal efficiency of phenol and was able to keep stable with the increase of initial phenol concentration. DO, pH, and salinity also affected the phenol removal rate. The most abundant bacterial group was phylum Proteobacteria in the two working conditions, and class Gammaproteobacteria as well as Alphaproteobacteria was predominant subgroup. The abundance of bacterial clusters was notably different along with the variation of operation conditions, resulting in changes of phenol degradation rates. The high removal efficiency of phenol suggested that the reactor might be promising in treating phenol-laden industrial wastewater in high-salt condition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Complete genome sequence of Desulfurivibrio alkaliphilus strain AHT2(T), a haloalkaliphilic sulfidogen from Egyptian hypersaline alkaline lakes

    NARCIS (Netherlands)

    Melton, E.D.; Sorokin, D.Y.; Overmars, L.; Chertkov, O.; Clum, A.; Pillay, M.; Ivanova, N.; Shapiro, N.; Kyrpides, N.C.; Woyke, T.; Lapidus, A.L.; Muyzer, G.

    2016-01-01

    Desulfurivibrio alkaliphilus strain AHT2T is a strictly anaerobic sulfidogenic haloalkaliphile isolated from a composite sediment sample of eight hypersaline alkaline lakes in the Wadi al Natrun valley in the Egyptian Libyan Desert. D. alkaliphilus AHT2T is Gram-negative and belongs to the family

  9. Heterotrophic denitrification at extremely high salt and pH by haloalkaliphilic Gammaproteobacteria from hypersaline soda lakes

    NARCIS (Netherlands)

    Shapovalova, A.A.; Khijniak, T.V.; Tourova, T.P.; Muyzer, G.; Sorokin, Y.

    2008-01-01

    In this paper we describe denitrification at extremely high salt and pH in sediments from hypersaline alkaline soda lakes and soda soils. Experiments with sediment slurries demonstrated the presence of acetate-utilizing denitrifying populations active at in situ conditions. Anaerobic enrichment

  10. Functional-Structural Analysis of Nitrogen-Cycle Bacteria in a Hypersaline Mat from the Omani Desert

    DEFF Research Database (Denmark)

    Abed, Raeid M M; de Beer, Dirk; Stief, Peter

    2015-01-01

    to sequences from the Rhizobiales group. Sequences of the nosZ gene were the most diverse and clustered with sequences from various genera. Our results demonstrate that the hypersaline mat from Oman harbors nitrifying and denitrifying bacteria with the potential to perform respective processes at detectable...

  11. 7 CFR 322.29 - Dead bees.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Dead bees. 322.29 Section 322.29 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation and Transit of...

  12. Cheatgrass Dead Zones in Northern Nevada

    Science.gov (United States)

    Reports of areas of cheatgrass die-off are becoming more frequent. In 2009, we investigated cheatgrass die-off in north-central Nevada. Dead zones ranged from several to hundreds of acres in size and were largely unvegetated and covered by cheatgrass litter with a distinct gray cast. We collected re...

  13. Tunnel Diode Discriminator with Fixed Dead Time

    DEFF Research Database (Denmark)

    Diamond, J. M.

    1965-01-01

    A solid state discriminator for the range 0.4 to 10 V is described. Tunnel diodes are used for the discriminator element and in a special fixed dead time circuit. An analysis of temperature stability is presented. The regulated power supplies are described, including a special negative resistance...

  14. Dinosaurs of India: Dead but Alive

    Indian Academy of Sciences (India)

    Table of contents. Dinosaurs of India: Dead but Alive · Fossils · Evolution and O2 PAL · The Science in Dinosaurs · Origin/ Extinction of Dinosaurs · PowerPoint Presentation · India –94my + 50my · Icehouse /Greenhouse through time · Global Mean Annual Temperature Distributions at 100 my · Global Mean Annual ...

  15. Effect of common dead space on VA/Q distribution in the dog.

    Science.gov (United States)

    Tsukimoto, K; Arcos, J P; Schaffartzik, W; Wagner, P D; West, J B

    1990-06-01

    Several previous studies have shown worsening ventilation-perfusion (VA/Q) relationships in humans during heavy exercise at sea level. However, the mechanism of this deterioration remains unclear because of the correlation with ventilatory and circulatory variables. Our hypothesis was that the decrease in the series dead space-to-tidal volume ratio during exercise might be partly responsible because mixing in the common dead space can reduce apparent inequality. We tested this notion in 10 resting anesthetized normocapnic dogs passively hyperventilated by increase tidal volume and a) inspired CO2 or b) external dead space. We predicted less apparent VA/Q inequality in condition b because of mixing in the added dead space. After base-line measurements, conditions a and b were randomly assigned, and after a second set of base-line measurements they were repeated in the reverse order in each dog. VA/Q inequality was measured by the multiple inert gas elimination technique. Comparison of conditions a and b demonstrated that additional external dead space improved (P less than 0.001) the blood flow distributions as hypothesized [log standard deviation of perfusion = 0.49 +/- 0.02 (SE) in condition b and 0.61 +/- 0.03 in condition a with respect to 0.52 +/- 0.03 at base line]. This study suggests that the increased tidal volume during exercise could uncover VA/Q inequality not evident at rest because of the higher ratio of common dead space to tidal volume at rest.

  16. Paleoecology of Neoproterozoic hypersaline environments: Biomarker evidence for haloarchaea, methanogens, and cyanobacteria.

    Science.gov (United States)

    Schinteie, R; Brocks, J J

    2017-09-01

    While numerous studies have examined modern hypersaline ecosystems, their equivalents in the geologic past, particularly in the Precambrian, are poorly understood. In this study, biomarkers from ~820 million year (Ma)-old evaporites from the Gillen Formation of the mid-Neoproterozoic Bitter Springs Group, central Australia, are investigated to elucidate the antiquity and paleoecology of halophiles. The sediments were composed of alternating laminae of dolomitized microbial mats and up to 90% anhydrite. Solvent extraction of these samples yielded thermally well-preserved hydrocarbon biomarkers. The regularly branched C25 isoprenoid 2,6,10,14,18-pentamethylicosane, the tail-to-tail linked C30 isoprenoid squalane, and breakdown products of the head-to-head linked C40 isoprenoid biphytane, were particularly abundant in the most anhydrite-rich sediments and mark the oldest current evidence for halophilic archaea. Linear correlations between isoprenoid concentrations (normalized to n-alkanes) and the anhydrite/dolomite ratio reveal microbial consortia that fluctuated with changing salinity levels. Halophilic archaea were the dominant organisms during periods of high salinity and gypsum precipitation, while bacteria were prevalent during stages of carbonate formation. The irregularly branched C25 isoprenoid 2,6,10,15,19-pentamethylicosane (PMI), with a central tail-to-tail link, was also abundant during periods of elevated salinity, highlighting the activity of methanogens. By contrast, the irregularly branched C20 isoprenoid 2,6,11,15-tetramethylhexadecane (crocetane) was more common in dolomite-rich facies, revealing that an alternate group of archaea was active during less saline periods. Elevated concentrations of isotopically depleted heptadecane (n-C17 ) revealed the presence of cyanobacteria under all salinity regimes. The combination of biomarkers in the mid-Neoproterozoic Gillen Formation resembles lipid compositions from modern hypersaline cyanobacterial mats

  17. Dark Skin No Shield from Deadly Skin Cancer

    Science.gov (United States)

    ... 166194.html Dark Skin No Shield From Deadly Skin Cancer Death rates from melanoma are higher for people ... deadly melanomas, an expert warns. This type of skin cancer can be affected by genetics and is far ...

  18. Gulf of Mexico dead zone - the last 150 years

    Science.gov (United States)

    Osterman, Lisa; Swarzenski, P.W.; Poore, R.Z.

    2006-01-01

    'Gulf of Mexico Dead Zone-The Last 150 Years' discusses the dead zone that forms seasonally in the northern Gulf of Mexico when subsurface waters become depleted in dissolved oxygen and cannot support most life.

  19. Survival strategies for microorganisms in hypersaline environments and their relevance to life on early Mars.

    Science.gov (United States)

    Litchfield, C D

    1998-07-01

    There are two groups of microorganisms that live and grow in hypersaline (>10-15% NaCl) environments: the halophilic Archaea and the halotolerant Bacteria and algae. In order to grow and reproduce in such high-salt, low-water activity environments, these organisms have made basic biochemical adaptations in their proteins, osmoregulation mechanisms, nucleic acids, and lipids. The environment of the halophiles and especially how the halophilic Archaea have adapted to that environment are reviewed in this paper. Along with this review is a brief description of how these adaptations could be important in the detection of life on early Mars assuming similar types of salts and a carbon-based life.

  20. High-pH-induced flocculation-flotation of the hypersaline microalga Dunaliella salina.

    Science.gov (United States)

    Besson, Alexandre; Guiraud, Pascal

    2013-11-01

    Natural autoflocculation was not observed in a Dunaliella salina hypersaline culture and the microalgae did not float without destabilization of the algal suspension. High-pH-induced flocculation by sodium hydroxide addition was chosen to induce flotation. Recovery efficiencies greater than 90% and concentration factors of around 20 were reached. An autoflocculation mechanism, with precipitation of magnesium hydroxide, is proposed to explain a sweeping flotation of D. salina cells. The influence of the flow rate of sodium hydroxide addition was also studied to anticipate the constraints related to the industrialization of this process. The flow rate of sodium hydroxide addition had no effect on the recovery efficiency and reduced the concentration factor only for abrupt injections. Natural increase of culture pH by photosynthetic activity could reduce the amount of base consumed. Non-harvested cells remained viable during pH increase and could be used as inoculum for a new culture. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Use of an Acoustic Doppler Current Profiler (ADCP) to Measure Hypersaline Bidirectional Discharge

    Science.gov (United States)

    Johnson, K.K.; Loving, B.L.; ,

    2002-01-01

    The U.S. Geological Survey measures the exchange of flow between the north and south parts of Great Salt Lake, Utah, as part of a monitoring program. Turbidity and bidirectional flow through the breach in the causeway that divides the lake into two parts makes it difficult to measure discharge with conventional streamflow techniques. An acoustic Doppler current profiler (ADCP) can be used to more accurately define the angles of flow and the location of the interface between the layers of flow. Because of the high salinity levels measured in Great Salt Lake (60-280 parts per thousand), special methods had to be developed to adjust ADCP-computed discharges for the increased speed of sound in hypersaline waters and for water entrained at the interface between flow layers.

  2. Diversity and distribution in hypersaline microbial mats of bacteria related to Chloroflexus spp.

    Science.gov (United States)

    Nübel, U; Bateson, M M; Madigan, M T; Kühl, M; Ward, D M

    2001-09-01

    Filamentous bacteria containing bacteriochlorophylls c and a were enriched from hypersaline microbial mats. Based on phylogenetic analyses of 16S rRNA gene sequences, these organisms form a previously undescribed lineage distantly related to Chloroflexus spp. We developed and tested a set of PCR primers for the specific amplification of 16S rRNA genes from filamentous phototrophic bacteria within the kingdom of "green nonsulfur bacteria." PCR products recovered from microbial mats in a saltern in Guerrero Negro, Mexico, were subjected to cloning or denaturing gradient gel electrophoresis and then sequenced. We found evidence of a high diversity of bacteria related to Chloroflexus which exhibit different distributions along a gradient of salinity from 5.5 to 16%.

  3. The Santa Pola saltern as a model for studying the microbiota of hypersaline environments.

    Science.gov (United States)

    Ventosa, Antonio; Fernández, Ana Beatriz; León, María José; Sánchez-Porro, Cristina; Rodriguez-Valera, Francisco

    2014-09-01

    Multi-pond salterns constitute an excellent model for the study of the microbial diversity and ecology of hypersaline environments, showing a wide range of salt concentrations, from seawater to salt saturation. Accumulated studies on the Santa Pola (Alicante, Spain) multi-pond solar saltern during the last 35 years include culture-dependent and culture-independent molecular methods and metagenomics more recently. These approaches have permitted to determine in depth the microbial diversity of the ponds with intermediate salinities (from 10% salts) up to salt saturation, with haloarchaea and bacteria as the two main dominant groups. In this review, we describe the main results obtained using the different methodologies, the most relevant contributions for understanding the ecology of these extreme environments and the future perspectives for such studies.

  4. Diversity and distribution in hypersaline microbial mats of bacteria related to Chloroflexus spp

    DEFF Research Database (Denmark)

    Nübel, Ulrich; Bateson, Mary M.; Madigan, Michael T.

    2001-01-01

    Filamentous bacteria containing bacteriochlorophylls c and a were enriched from hypersaline microbial mats. Based on phylogenetic analyses of 16S rRNA gene sequences, these organisms form a previously undescribed lineage distantly related to Chloroflexus spp. We developed and tested a set of PCR...... primers for the specific amplification of 16S rRNA genes from filamentous phototrophic bacteria within the kingdom of "green nonsulfur bacteria." PCR products recovered from microbial mats in a saltern in Guerrero Negro, Mexico, were subjected to cloning or denaturing gradient gel electrophoresis...... and then sequenced. We found evidence of a high diversity of bacteria related to Chloroflexus which exhibit different distributions along a gradient of salinity from 5.5 to 16%....

  5. Modeling of membrane bioreactor treating hypersaline oily wastewater by artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Pendashteh, Ali Reza [Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor D.E. (Malaysia); Environmental Research Institute, Iranian Academic Center for Education, Culture and Research (ACECR), Rasht (Iran, Islamic Republic of); Fakhru' l-Razi, A., E-mail: fakhrul@eng.upm.edu.my [Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor D.E. (Malaysia); Chaibakhsh, Naz [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor D.E. (Malaysia); Abdullah, Luqman Chuah [Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor D.E. (Malaysia); Madaeni, Sayed Siavash [Chemical Engineering Department, Razi University, Kermanshah (Iran, Islamic Republic of); Abidin, Zurina Zainal [Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor D.E. (Malaysia)

    2011-08-30

    Highlights: {yields} Hypersaline oily wastewater was treated in a membrane bioreactor. {yields} The effects of salinity and organic loading rate were evaluated. {yields} The system was modeled by neural network and optimized by genetic algorithm. {yields} The model prediction agrees well with experimental values. {yields} The model can be used to obtain effluent characteristics less than discharge limits. - Abstract: A membrane sequencing batch reactor (MSBR) treating hypersaline oily wastewater was modeled by artificial neural network (ANN). The MSBR operated at different total dissolved solids (TDSs) (35,000; 50,000; 100,000; 150,000; 200,000; 250,000 mg/L), various organic loading rates (OLRs) (0.281, 0.563, 1.124, 2.248, and 3.372 kg COD/(m{sup 3} day)) and cyclic time (12, 24, and 48 h). A feed-forward neural network trained by batch back propagation algorithm was employed to model the MSBR. A set of 193 operational data from the wastewater treatment with the MSBR was used to train the network. The training, validating and testing procedures for the effluent COD, total organic carbon (TOC) and oil and grease (O and G) concentrations were successful and a good correlation was observed between the measured and predicted values. The results showed that at OLR of 2.44 kg COD/(m{sup 3} day), TDS of 78,000 mg/L and reaction time (RT) of 40 h, the average removal rate of COD was 98%. In these conditions, the average effluent COD concentration was less than 100 mg/L and met the discharge limits.

  6. Osmoadaptive strategies of the archaeon Halococcus hamelinensis isolated from a hypersaline stromatolite environment.

    Science.gov (United States)

    Goh, Falicia; Jeon, Young Jae; Barrow, Kevin; Neilan, Brett A; Burns, Brendan P

    2011-01-01

    Biogenic stromatolites are sources of significant information on the evolution of microbial life. Despite their evolutionary significance, little is known about the mechanisms of osmoadaptation by microorganisms that comprise living stromatolites thriving in hypersaline environments. Osmoadaptive strategies for Halococcus hamelinensis, a novel halophilic archaeon recently isolated from living stromatolites in the hypersaline reaches of Shark Bay, were thus a particular interest in this study. To investigate the possibility of "salt-in-cytoplasm"-associated osmoadaptation for this archaeon, flame photometry studies were performed. From the results, it was evident that this halophilic archaeon did not accumulate intracellular K(+) ions when cells were exposed to either osmotic shock or conditions with gradual increments in salinity. These results were further supported by polymerase chain reaction (PCR) analyses where there was no evidence for the existence of homologous genes to an ATP-driven, high-affinity potassium uptake system in Halococcus hamelinensis. To identify an alternative salt adaptation mechanism associated with accumulation of compatible solutes for this archaeon, (1)H nuclear magnetic resonance (NMR) spectroscopy experiments were carried out. Results indicate that glycine betaine, trehalose, and glutamate are solutes likely to be involved in osmoregulation in this archeaon. Subsequent (1)H NMR analysis of cell extracts from this microorganism grown under various NaCl concentrations revealed that intracellular levels of glycine betaine increased with increasing concentrations of NaCl. This behavior of increasing glycine betaine concentration with increasing external NaCl is consistent with its identity as an osmolyte. In contrast, intracellular levels of trehalose were decreased in high concentrations of NaCl. This provides evidence that compatible solute accumulation appears to be the preferential salt regulation mechanism for this haloarchaeon, in

  7. 10 CFR 1047.7 - Use of deadly force.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Use of deadly force. 1047.7 Section 1047.7 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) LIMITED ARREST AUTHORITY AND USE OF FORCE BY PROTECTIVE FORCE OFFICERS General Provisions § 1047.7 Use of deadly force. (a) Deadly force means that force which a...

  8. 14 CFR 1203b.106 - Use of deadly force.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Use of deadly force. 1203b.106 Section... AUTHORITY AND USE OF FORCE BY NASA SECURITY FORCE PERSONNEL § 1203b.106 Use of deadly force. Deadly force shall be used only in those circumstances where the security force officer reasonably believes that...

  9. The zero inflation of standing dead tree carbon stocks

    Science.gov (United States)

    Christopher W. Woodall; David W. MacFarlane

    2012-01-01

    Given the importance of standing dead trees in numerous forest ecosystem attributes/processes such as carbon (C) stocks, the USDA Forest Service’s Forest Inventory and Analysis (FIA) program began consistent nationwide sampling of standing dead trees in 1999. Modeled estimates of standing dead tree C stocks are currently used as the official C stock estimates for the...

  10. 46 CFR 111.10-7 - Dead ship.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Dead ship. 111.10-7 Section 111.10-7 Shipping COAST... REQUIREMENTS Power Supply § 111.10-7 Dead ship. (a) The generating plant of each self-propelled vessel must provide the electrical services necessary to start the main propulsion plant from a dead ship condition...

  11. Standing dead tree resources in forests of the United States

    Science.gov (United States)

    Christopher W. Woodall; Karen L. Waddell; Christopher M. Oswalt; James E. Smith

    2013-01-01

    Given the importance of standing dead trees to numerous forest ecosystem attributes/ processes such as fuel loadings and wildlife habitat, the Forest Inventory and Analysis (FIA) Program of the Forest Service, U.S. Department of Agriculture, initiated a consistent nationwide inventory of standing dead trees in 1999. As the first cycle of annual standing dead tree...

  12. Surviving deadness in the analytic experience.

    Science.gov (United States)

    Koritar, Endre

    2014-12-01

    The transference/countertransference (third space) analysis is considered to be central in the therapeutic effectiveness of the analytic process. Less emphasis has been placed on the actual experiences of analyst and analysand in the conflictual reenactment of third space experience and its resolution. This paper recounts the shared experience of a patient who was silent throughout most of the analysis, and my reaction, in fantasy and enactment, to this disturbing experience-both for him and for myself. I argue that it is the affective re-experiencing of past repressed trauma in the analytic space that has a therapeutic impact, leading to growth in the patient and also the therapist. I contrast Freud's emphasis on insight, making the unconscious conscious, with Ferenczi's suggestion that the therapeutic impact lies in the repetition of past traumatic experience in the analysis but with the possibility of a different outcome with a more benign object, leading to symbolic representation of repressed trauma. Re-experiencing and symbolization, in the third space, of past traumatic experience can be an exit point from the endless repetition of trauma in internal and external object relations, leading to a new beginning in the patient's life. Immersed in the experience of deadness in the analysis, which had become a dead womb, the struggle to remain alive and thinking led to a rupture out of the dead womb, like the Caesura of birth, into aliveness and the ability to mentalize what had previously remained unmentalized.

  13. A brine interface in the Salton Sea Geothermal System, California: Fluid geochemical and isotopic characteristics

    Science.gov (United States)

    Williams, Alan E.; McKibben, Michael A.

    1989-08-01

    Data from 71 geothermal production intervals in 48 wells from the Salton Sea Geothermal System (SSGS) indicate that fluids in that system cluster into two distinct populations in terms of their salinity and their stable isotopic compositions. The distinctive, hot, hypersaline brine (typically >20 wt% total dissolved solids) for which the SSGS is known is overlain by a cooler (barrier to convective heat and mass transfer in the SSGS, isolating the hypersaline reservoir from overlying dilute fluids. A lithologic "cap" implied by previous SSGS models is unnecessary in such a stratified system since heat and mass transfer across the interface must occur by slow conductive, diffusional and interface mixing processes regardless of local permeability.

  14. Visualization of deuterium dead layer by atom probe tomography

    KAUST Repository

    Gemma, Ryota

    2012-12-01

    The first direct observation, by atom probe tomography, of a deuterium dead layer is reported for Fe/V multilayered film loaded with D solute atoms. The thickness of the dead layers was measured to be 0.4-0.5 nm. The dead layers could be distinguished from chemically intermixed layers. The results suggest that the dead layer effect occurs even near the interface of the mixing layers, supporting an interpretation that the dead layer effect cannot be explained solely by electronic charge transfer but also involves a modulation of rigidity. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  15. Microbial diversity in sediment ecosystems (evaporites domes, microbial mats and crusts) of hypersaline Laguna Tebenquiche, Salar de Atacama, Chile

    OpenAIRE

    Ana Beatriz Fernandez; Maria Cecilia Rasuk; Visscher, Pieter T.; Manuel Contreras; Fernando Novoa; Daniel Poire; Patterson, Molly M.; Antonio Ventosa; Maria Eugenia Farias

    2016-01-01

    We combined nucleic acid-based molecular methods, biogeochemical measurements and physicochemical characteristics to investigate microbial sedimentary ecosystems of Laguna Tebenquiche, Atacama Desert, Chile. Molecular diversity and biogeochemistry of hypersaline microbial mats, rhizome-associated concretions and an endoevaporite were compared with: The V4 hypervariable region of the 16S rRNA gene was amplified by pyrosequencing to analyze the total microbial diversity (i.e., bacteria and arch...

  16. Limitation of oxygenic photosynthesis and oxygen consumption by phosphate and organic nitrogen in a hypersaline microbial mat : a microsensor study

    OpenAIRE

    R. Ludwig; Pringault, Olivier; Wit, R.; De Beer, D; Jonkers, H.M.

    2006-01-01

    Microbial mats are characterized by high primary production but low growth rates, pointing to a limitation of growth by the lack of nutrients or substrates. We identified compounds that instantaneously stimulated photosynthesis rates and oxygen consumption rates in a hypersaline microbial mat by following the short-term response (c. 6 h) of these processes to addition of nutrients, organic and inorganic carbon compounds, using microsensors. Net photosynthesis rates were not stimulated by comp...

  17. The modulation of leaf metabolism plays a role in salt tolerance of Cymodocea nodosa exposed to hypersaline stress in mesocosms

    Directory of Open Access Journals (Sweden)

    Amalia ePiro

    2015-06-01

    Full Text Available By the proteomic approach we tested the physiological responses of the euryhaline seagrass Cymodocea nodosa to deliberate manipulation of salinity in a mesocosm system. Plants were subjected to a chronic hypersaline condition (43 psu to compare their proteins expression and plant photochemistry responses after 15 and 30 days of exposure with those of plants cultured under normal/ambient saline conditions (37 psu. Results showed a general decline in the expression level of leaf proteins in hypersaline stressed plants, with more intense reductions on the long-lasting exposure. Specifically, the carbon-fixing enzyme RuBisCo displayed a lower expression level in stressed plants relative to controls; while contrarily, the key enzymes involve in the regulation of glycolisis, the cytosolic glyceraldehyde-3-phopsphate dehydrogenase, the enolase 2 and triose-phosphate isomerase, showed significant higher expression levels. Responses that suggest a shift of the carbon metabolism in stressed plants. Hypersaline stress also induced a significant alteration of the photosynthetic physiology of the C. nodosa by means of the down-regulation of structural proteins and enzymes of both PSII and PSI; however we found an over-expression of the cytochrome b559 alpha subunit of the PSII initial complex, which is a receptor for the PSII core proteins involved in biogenesis or repair processes and therefore potentially involved in the absence of effects at the photochemical level of stressed plants. As expected hypersalinity also affects the vacuolar metabolism increasing the leaf cell turgor pressure and enhancing the up-take of Na+ by the over-expression of the tonoplast specific intrinsic protein pyrophosphate-energized inorganic pyrophosphatase (H(+-PPase that is coupled with the Na+/H+-antiporter. The modulation of carbon metabolism and the enhancement of vacuole capacity in Na+ sequestration and osmolarity changes are discussed in relation to salt tolerance of C

  18. Potentially mobile of heavy metals on the surface sediments in tropical hyper-saline and positive estuaries

    Directory of Open Access Journals (Sweden)

    CARLOS A. RAMOS E SILVA

    Full Text Available ABSTRACT Estuarine sediments represent important pools of trace metals, released from both anthropogenic and natural sources. Fluctuations in the water column physicochemical conditions, on the other hand, may transfer metals from solid to liquid compartment and resulting in contamination of the surrounding environment. The present research was carried out to evaluate the weakly bounded heavy metal levels in tropical hyper-saline and positive estuaries, in order to quantify its potentially availability. The monitoring includes five metals (Cd, Cr, Cu, Pb, Zn and cover nine estuaries in Rio Grande do Norte state/Brazil, including four hypersaline and five true estuaries. 50 surface sediment samples were collected in each estuary. At the same time, organic matter concentrations were evaluated in order to help explaining possible local variations in heavy metal levels. Organic matter results (0.7% - 7.3% suggest the positive Potengi estuary as the most critical environmental quality situation. On the other hand, according to heavy metals levels, both Conchas and Potengi estuaries registered the higher concentrations of Cr. The highest concentrations were observed in the hyper-saline estuaries, with the exception of the Zn. The present study revealed that the watershed occupation has significantly influenced the heavy metal concentrations in the estuaries.

  19. Hypersaline groundwater genesis assessment through a multidisciplinary approach: the case of Pozzo del Sale Spring (southern Italy)

    Science.gov (United States)

    Celico, Fulvio; Capuano, Paolo; de Felice, Vincenzo; Naclerio, Gino

    2008-11-01

    A tool, based on a multidisciplinary field investigation approach for studying the characteristics of a hypersaline spring, was developed and its effectiveness tested on a spring in southern Italy; a preliminary model of the aquifer system at medium and local scale was derived. Hydrologic measurements, vertical electric soundings, and chemical and isotopic (δ18O, δ2H, 3H) analyses were undertaken, along with microbiological analyses and species identification. These demonstrate the coexistence of hypersaline and fresh water, generating a significant diversification of the groundwater hydrochemical signature. The isotopic signature shows that both types of water have a meteoric origin. Microbial contamination of fecal origin indicates the mixing of hyper- and low- saline water related to local infiltration. The hypersaline groundwater flows in confined horizons within a sequence that is mainly of fractured clays. These horizons are probably concentrated where well-developed fracture network and dissolution openings within evaporitic rocks enhance fluid flow. In a wider context, this study determines that microbiological pollution of saline groundwater may not be detected if using nonhalophilic bacterial indicators such as fecal coliforms. Fecal enterococci are better indicators, due to their higher halotolerance.

  20. 50 CFR 223.206 - Exceptions to prohibitions relating to sea turtles.

    Science.gov (United States)

    2010-10-01

    ... to prohibitions relating to sea turtles. (a) Permits—(1) Scientific research, education, zoological... zoological exhibition, or to enhance the propagation or survival of threatened species of sea turtles, in... of sea turtle is found injured, dead, or stranded, any agent or employee of the National Marine...

  1. Autopsies of the real: Resurrecting the dead

    OpenAIRE

    Valis, Noël

    2011-01-01

    The sense of the real, or the material—the dead body—as an inextricable part of the sacred does not disappear in the secular environment of the nineteenth and twentieth centuries. This article analyzes specific humanitarian narratives centered on the practice of autopsy and mummification, in which the traces of Catholicism act as a kind of spectral discourse of the imagination, where the real is configured in forms of the uncanny, the monstrous or the sacred.

    El sentido de ...

  2. [A case of lycanthropy with deadly violence].

    Science.gov (United States)

    Bénézech, M; De Witte, J; Etchepare, J J; Bourgeois, M

    1989-01-01

    After a short historical review of the contemporary medical literature, the authors analyze a new and original observation of lycanthropy. He is a 28 years old man, imprisoned for deadly violence, who has been showing, for many years, the belief of being transformed into a werewolf during depersonalization episodes when he presents a lycanthropic behaviour. Our observation is closer to hysteria and mythomania on an antisocial personality, although it seems difficult to place the mental pathology of this alcoholic recidivist delinquent into a nosographical frame.

  3. Dead time optimization method for power converter

    Science.gov (United States)

    Deselaers, C.; Bergmann, U.; Gronwald, F.

    2013-07-01

    This paper introduces a method for dead time optimization in variable speed motor drive systems. The aim of this method is to reduce the conduction time of the freewheeling diode to a minimum without generation of cross conduction. This results in lower losses, improved EMC, and less overshooting of the phase voltage. The principle of the method is to detect beginning cross currents without adding additional components in the half bridge like resistors or inductances. Only the wave shape of the phase voltage needs to be monitored during switching. This is illustrated by an application of the method to a real power converter.

  4. The geomorphology of two hyper-saline springs in the Canadian High Arctic

    Science.gov (United States)

    Ward, Melissa; Pollard, Wayne

    2015-04-01

    On Axel Heiberg Island in the Canadian High Arctic, many low temperature perennial saline springs occur despite cold polar desert climate conditions marked by a mean annual air temperature of -18°C. Associated with 2 groups of hyper-saline springs are distinctive landforms resulting from winter deposition of salt minerals. These deposits resemble tufas structurally, but unlike true tufas which are composed of carbonate minerals, these landforms are formed mainly of salt. This study hypothesizes that the extreme cold winter air temperatures cool water temperatures triggering rapid precipitation of various salt minerals [mainly hydrohalite (NaCl*2H2O)]. These newly formed salt minerals subsequently alter the flow hydrology by obstructing summer flow paths. The tufa-like appearance of these salt deposits reflects the interaction between changing water temperature, chemistry and flow.This research characterises the geomorphology and geochemistry of two hyper-saline springs on Axel Heiberg Island: the first is located at Wolf Diapir (79°07'23"N; 90°14'39"W), the deposit at this site resembles a large conical mound (2.5m tall x 3m diameter). The second is located at Stolz Diapir (79°04'30"N; 87°04'30"W). In this case a series of pool and barrage structures staircase down a narrow valley for approximately 300m (several pools are up to 10 m wide x 3 m deep). The springs have very different seasonal surface hydrologic regimes and topographic settings which influence the pattern of mineral precipitates. The accumulation of precipitates occurs during the winter and is dominated by the formation of hydrohalite. In the summer, the accumulated hydrohalite melts incongruently to form halite. In addition, spring water and snowmelt dissolve various parts of the accumulations, changing the morphology of the deposits. This presentation will focus on results from four periods of fieldwork (two in spring for winter conditions and two in summer) including results from time

  5. Calcium Biomineralization in Sediment of Lake Acigol, an Hypersaline Lake in SW Turkey

    Science.gov (United States)

    Celik Balci, Nurgul; Menekse, Meryem; Sonmez, Seref; Gul Karaguler, Nevin

    2010-05-01

    The study of biomineralization in (hyper) saline environments is important for two reasons, 1-it can extend our knowledge about the earliest microbial life on Earth which may have been halophilic 2-because of the presence of hypersaline conditions on Mars, the analog environments in Earth may have implications for the possibility of life on Mars. We examine calcium biomineralization in Lake Acigol, a unique hypersaline lake in southwest Turkey by integrating geochemical and microbiological approaches. Lake Acigol is a perennial lake with a maximum salinity of about 200 g/L and covers an area of 55-60 km2and is one of the main salt reservoirs of Turkey. Water, sediment and core samples were taken from the lake and salty ponds around the lake during the field excursion. The water chemistry revealed relatively high Na and SO4 concentrations both in the lake (30 gr/L, 33.36 gr/L), and the ponds (100 mg/L, 123 mg/L). The mineralogical analyses of sediments showed gypsum, halite, carbonate (aragonite, huntite) precipitation in the lake and ponds. We employed culture-dependent (16s rRNA cloning method, enrichment culture), and -independent techniques to study microbial diversity in Lake Aci gol. Sediment samples were used to isolate Halophilic sp. (e.g. salinicoccus roseus , Dunella sp.) under salinities that were similar to those measured in the lake water to further use in the laboratory Ca-precipitation experiments. For the precipitation experiments, liquid and solid culture media with various salinities ( 6-25 %) in addition to one similar to the lake water were prepared. In order to determine effect of Mg2+-Ca2+ molar ratio on mineralogy and the rate of precipitation, media with different Ca2+and Mg2+ concentrations were also prepared. Our preliminary results indicate that the halophilic bacteria play active role in the precipitation of Ca-minerals but the geochemical conditions are clearly influential. The results also point out that in the Lake Aci gol C, N, P, Ca

  6. When the dead are alive! The influence of the living dead in the letter of Jude

    Directory of Open Access Journals (Sweden)

    Stephan J. Joubert

    2002-11-01

    Full Text Available This essay investigates the impact of the deceased on  the audience to which the letter of Jude was originally addressed. A construct of the influence of the “living dead” in ancient Babylon, Israel, the Graeco-Roman world and in African tradition serves as a basic cognitive map to come to terms with Jude’s views on the dead. It is argued that, since the wicked dead, who are being physically punished in  the underworld,  are kept alive  in the collective memory of Jude’s community and since their deeds are re-enacted in the sinful behavior  of intruders in their midst, their lives are influenced by  the “presence” of these living dead. On the other hand and, although Jude does not deal with the physical whereabouts of the righteous death, he and his readers know that their postmortem honour is still intact. The righteous in this community is assured that God protects the integrity of the faithful dead.

  7. Asteroid 'Bites the Dust' Around Dead Star

    Science.gov (United States)

    2009-01-01

    NASA's Spitzer Space Telescope set its infrared eyes upon the dusty remains of shredded asteroids around several dead stars. This artist's concept illustrates one such dead star, or 'white dwarf,' surrounded by the bits and pieces of a disintegrating asteroid. These observations help astronomers better understand what rocky planets are made of around other stars. Asteroids are leftover scraps of planetary material. They form early on in a star's history when planets are forming out of collisions between rocky bodies. When a star like our sun dies, shrinking down to a skeleton of its former self called a white dwarf, its asteroids get jostled about. If one of these asteroids gets too close to the white dwarf, the white dwarf's gravity will chew the asteroid up, leaving a cloud of dust. Spitzer's infrared detectors can see these dusty clouds and their various constituents. So far, the telescope has identified silicate minerals in the clouds polluting eight white dwarfs. Because silicates are common in our Earth's crust, the results suggest that planets similar to ours might be common around other stars.

  8. Breathing Life Into Dead-Zones

    Directory of Open Access Journals (Sweden)

    Gressel Oliver

    2013-04-01

    Full Text Available The terrestrial planet formation regions of protoplanetary disks are generally sufficiently cold to be con- sidered non-magnetized and, consequently, dynamically inactive. However, recent investigations of these so-called “Dead-Zones” indicate the possibility that disks with strong mean radial temperature gradients can support instabilities associated with disk-normal gradients of the basic Keplerian shear profile. This process, known as the Goldreich-Schubert-Fricke (GSF instability, is the instability of short radial wavelength inertial modes and depends wholly on the presence of vertical gradients of the mean Keplerian (zonal flow. We report here high resolution fully nonlinear axisymmetric numerical studies of this instability and find a number of features including how, in the nonlinear saturated state, unstable discs become globally distorted, with strong vertical oscillations occurring at all radii due to local instability. We find that nonaxisymmetric numerical experiments are accompanied by significant amounts angular momentum transport (α ~ 0001. This instability should be operating in the Dead-Zones of protoplanetary disks at radii greater than 10-15 AU in minimum mass solar nebula models.

  9. Severe fish mortality associated with 'red tide' observed in the sea off Cochin

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.; George, M.D.; Narvekar, P.V.; Jayakumar, D.A.; Shailaja, M.S.; Sardessai, S.; Sarma, V.V.S.S.; Shenoy, D.M.; Naik, H.; Maheswaran, P.A.; KrishnaKumari, L.; Rajesh, G.; Sudhir, A.K.; Binu, M.S.

    Severe fish mortality associated with the "red tide" phenomenon caused by Noctiluca blooms was observed in the sea off Cochin, Kerala, India at depths less than 40 m. The dead fish, almost entirely comprised of the threadfin bream (Nemipterus...

  10. Photographic Study Of A Dead-Pressed Explosive

    Science.gov (United States)

    Swallowe, G. M.; Field, J. E.

    1983-03-01

    High speed photography in conjunction with electron microscopy and a pressure measuring technique have been used to investigate the differences between dead-pressed and non-dead-pressed samples of the primary explosive Mercury Fulminate (Hg Ful). Photographs of reaction propagation were taken in transmitted light using a specially adapted drop-weight machine with transparent anvils. The results of these experiments suggested a mechanism for dead-pressing in Hg Ful based on the microscopic internal structure of the compacted explosive.

  11. Primary and heterotrophic productivity relate to multikingdom diversity in a hypersaline mat

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Hans C.; Brislawn, Colin J.; Dana, Karl; Flores-Wentz, Tobias; Cory, Alexandra B.; Fansler, Sarah J.; Fredrickson, James K.; Moran, James J.

    2017-10-01

    Benthic microbial ecosystems are widespread yet knowledge gaps still remain on the relationships between the diversity of species across kingdoms and productivity. Here, we ask two fundamental questions: 1) How does species diversity relate to the rates of primary and heterotrophic productivity? 2) How do diel variations in light-energy inputs influence productivity and microbiome diversity? To answer these questions, microbial mats from a magnesium sulfate hypersaline Lake were used to establish microcosms. Both the number and relatedness between bacterial and eukaryotic taxa in the microbiome were assayed via amplicon based sequencing of 16S and 18S rRNA genes over two diel cycles. These results correlated with biomass productivity obtained from substrate-specific 13C stable isotope incorporation that enabled comparisons between primary and heterotrophic productivity. Both bacterial and eukaryotic species richness and evenness were related only to the rates of 13C labeled glucose and acetate biomass incorporation. Interestingly, measures of these heterotrophic relationships changed from positive and negative correlations depending on carbon derived from glucose and acetate, respectively. Bacterial and eukaryotic diversity of this ecosystem is also controlled, in part, energy constraints imposed by changing irradiance over a diel cycle.

  12. Archaeal populations in hypersaline sediments underlying orange microbial mats in the Napoli mud volcano.

    Science.gov (United States)

    Lazar, Cassandre Sara; L'haridon, Stéphane; Pignet, Patricia; Toffin, Laurent

    2011-05-01

    Microbial mats in marine cold seeps are known to be associated with ascending sulfide- and methane-rich fluids. Hence, they could be visible indicators of anaerobic oxidation of methane (AOM) and methane cycling processes in underlying sediments. The Napoli mud volcano is situated in the Olimpi Area that lies on saline deposits; from there, brine fluids migrate upward to the seafloor. Sediments associated with a brine pool and microbial orange mats of the Napoli mud volcano were recovered during the Medeco cruise. Based on analysis of RNA-derived sequences, the "active" archaeal community was composed of many uncultured lineages, such as rice cluster V or marine benthic group D. Function methyl coenzyme M reductase (mcrA) genes were affiliated with the anaerobic methanotrophic Archaea (ANME) of the ANME-1, ANME-2a, and ANME-2c groups, suggesting that AOM occurred in these sediment layers. Enrichment cultures showed the presence of viable marine methylotrophic Methanococcoides in shallow sediment layers. Thus, the archaeal community diversity seems to show that active methane cycling took place in the hypersaline microbial mat-associated sediments of the Napoli mud volcano.

  13. Archaeal Populations in Hypersaline Sediments Underlying Orange Microbial Mats in the Napoli Mud Volcano▿†

    Science.gov (United States)

    Lazar, Cassandre Sara; L'Haridon, Stéphane; Pignet, Patricia; Toffin, Laurent

    2011-01-01

    Microbial mats in marine cold seeps are known to be associated with ascending sulfide- and methane-rich fluids. Hence, they could be visible indicators of anaerobic oxidation of methane (AOM) and methane cycling processes in underlying sediments. The Napoli mud volcano is situated in the Olimpi Area that lies on saline deposits; from there, brine fluids migrate upward to the seafloor. Sediments associated with a brine pool and microbial orange mats of the Napoli mud volcano were recovered during the Medeco cruise. Based on analysis of RNA-derived sequences, the “active” archaeal community was composed of many uncultured lineages, such as rice cluster V or marine benthic group D. Function methyl coenzyme M reductase (mcrA) genes were affiliated with the anaerobic methanotrophic Archaea (ANME) of the ANME-1, ANME-2a, and ANME-2c groups, suggesting that AOM occurred in these sediment layers. Enrichment cultures showed the presence of viable marine methylotrophic Methanococcoides in shallow sediment layers. Thus, the archaeal community diversity seems to show that active methane cycling took place in the hypersaline microbial mat-associated sediments of the Napoli mud volcano. PMID:21335391

  14. Microbial diversity of extant stromatolites in the hypersaline marine environment of Shark Bay, Australia.

    Science.gov (United States)

    Burns, Brendan P; Goh, Falicia; Allen, Michelle; Neilan, Brett A

    2004-10-01

    Stromatolites have been present on Earth, at various levels of distribution and diversity, for more than 3 billion years. Today, the best examples of stromatolites forming in hypersaline marine environments are in Hamelin Pool at Shark Bay, Western Australia. Despite their evolutionary significance, little is known about their associated microbial communities. Using a polyphasic approach of culture-dependent and culture-independent methods, we report the discovery of a wide range of microorganisms associated with these biosedimentary structures. There are no comparable reports combining these methodologies in the survey of cyanobacteria, bacteria, and archaea in marine stromatolites. The community was characterized by organisms of the cyanobacterial genera Synechococcus, Xenococcus, Microcoleus, Leptolyngbya, Plectonema, Symploca, Cyanothece, Pleurocapsa and Nostoc. We also report the discovery of potentially free-living Prochloron. The other eubacterial isolates and clones clustered into seven phylogenetic groups: OP9, OP10, Marine A group, Proteobacteria, Low G+C Gram-positive, Planctomycetes and Acidobacteria. We also demonstrate the presence of sequences corresponding to members of halophilic archaea of the divisions Euryarchaeota and Crenarchaeota and methanogenic archaea of the order Methanosarcinales. This is the first report of such archaeal diversity from this environment. This study provides a better understanding of the microbial community associated with these living rocks.

  15. Composition and Activity of Microbial Communities along the Redox Gradient of an Alkaline, Hypersaline, Lake

    Directory of Open Access Journals (Sweden)

    Christian F. Edwardson

    2018-01-01

    Full Text Available We compared the composition of microbial communities obtained by sequencing 16S rRNA gene amplicons with taxonomy derived from metatranscriptomes from the same samples. Samples were collected from alkaline, hypersaline Mono Lake, California, USA at five depths that captured the major redox zones of the lake during the onset of meromixis. The prokaryotic community was dominated by bacteria from the phyla Proteobacteria, Firmicutes, and Bacteroidetes, while the picoeukaryotic chlorophyte Picocystis dominated the eukaryotes. Most (80% of the abundant (>1% relative abundance OTUs recovered as amplicons of 16S rRNA genes have been reported in previous surveys, indicating that Mono Lake's microbial community has remained stable over 12 years that have included periods of regular, annual overturn interspersed by episodes of prolonged meromixis that result in extremely reducing conditions in bottom water. Metatranscriptomic sequences binned predominately to the Gammaproteobacteria genera Thioalkalivibrio (4–13% and Thioalkalimicrobium (0–14%; and to the Firmicutes genera Dethiobacter (0–5% and Clostridium (1–4%, which were also abundant in the 16S rRNA gene amplicon libraries. This study provides insight into the taxonomic affiliations of transcriptionally active communities of the lake's water column under different redox conditions.

  16. Potential for Plant Growth Promotion of Rhizobacteria Associated with Salicornia Growing in Tunisian Hypersaline Soils

    Directory of Open Access Journals (Sweden)

    Francesca Mapelli

    2013-01-01

    Full Text Available Soil salinity and drought are among the environmental stresses that most severely affect plant growth and production around the world. In this study the rhizospheres of Salicornia plants and bulk soils were collected from Sebkhet and Chott hypersaline ecosystems in Tunisia. Depiction of bacterial microbiome composition by Denaturing Gradient Gel Electrophoresis unveiled the occurrence of a high bacterial diversity associated with Salicornia root system. A large collection of 475 halophilic and halotolerant bacteria was established from Salicornia rhizosphere and the surrounding bulk soil, and the bacteria were characterized for the resistance to temperature, osmotic and saline stresses, and plant growth promotion (PGP features. Twenty Halomonas strains showed resistance to a wide set of abiotic stresses and were able to perform different PGP activities in vitro at 5% NaCl, including ammonia and indole-3-acetic acid production, phosphate solubilisation, and potential nitrogen fixation. By using a gfp-labelled strain it was possible to demonstrate that Halomonas is capable of successfully colonising Salicornia roots in the laboratory conditions. Our results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions. These halophilic/halotolerant strains could be exploited in biofertilizer formulates to sustain crop production in degraded and arid lands.

  17. Sustainable Hypersaline Microbial Fuel Cells: Inexpensive Recyclable Polymer Supports for Carbon Nanotube Conductive Paint Anodes.

    Science.gov (United States)

    Grattieri, Matteo; Shivel, Nelson D; Sifat, Iram; Bestetti, Massimiliano; Minteer, Shelley D

    2017-05-09

    Microbial fuel cells are an emerging technology for wastewater treatment, but to be commercially viable and sustainable, the electrode materials must be inexpensive, recyclable, and reliable. In this study, recyclable polymeric supports were explored for the development of anode electrodes to be applied in single-chamber microbial fuel cells operated in field under hypersaline conditions. The support was covered with a carbon nanotube (CNT) based conductive paint, and biofilms were able to colonize the electrodes. The single-chamber microbial fuel cells with Pt-free cathodes delivered a reproducible power output after 15 days of operation to achieve 12±1 mW m -2 at a current density of 69±7 mA m -2 . The decrease of the performance in long-term experiments was mostly related to inorganic precipitates on the cathode electrode and did not affect the performance of the anode, as shown by experiments in which the cathode was replaced and the fuel cell performance was regenerated. The results of these studies show the feasibility of polymeric supports coated with CNT-based paint for microbial fuel cell applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Sequence analysis of an Archaeal virus isolated from a hypersaline lake in Inner Mongolia, China

    Directory of Open Access Journals (Sweden)

    Ma Yanhe

    2007-11-01

    Full Text Available Abstract Background We are profoundly ignorant about the diversity of viruses that infect the domain Archaea. Less than 100 have been identified and described and very few of these have had their genomic sequences determined. Here we report the genomic sequence of a previously undescribed archaeal virus. Results Haloarchaeal strains with 16S rRNA gene sequences 98% identical to Halorubrum saccharovorum were isolated from a hypersaline lake in Inner Mongolia. Two lytic viruses infecting these were isolated from the lake water. The BJ1 virus is described in this paper. It has an icosahedral head and tail morphology and most likely a linear double stranded DNA genome exhibiting terminal redundancy. Its genome sequence has 42,271 base pairs with a GC content of ~65 mol%. The genome of BJ1 is predicted to encode 70 ORFs, including one for a tRNA. Fifty of the seventy ORFs had no identity to data base entries; twenty showed sequence identity matches to archaeal viruses and to haloarchaea. ORFs possibly coding for an origin of replication complex, integrase, helicase and structural capsid proteins were identified. Evidence for viral integration was obtained. Conclusion The virus described here has a very low sequence identity to any previously described virus. Fifty of the seventy ORFs could not be annotated in any way based on amino acid identities with sequences already present in the databases. Determining functions for ORFs such as these is probably easier using a simple virus as a model system.

  19. Microbial Diversity of the Hypersaline Sidi Ameur and Himalatt Salt Lakes of the Algerian Sahara.

    Science.gov (United States)

    Boutaiba, Saad; Hacene, Hocine; Bidle, Kelly A; Maupin-Furlow, Julie A

    2011-10-01

    Microbial populations within hypersaline lakes often exhibit high activities of photosynthesis, dissimilatory sulphate reduction and other processes and, thus, can have profound impacts on biogeochemical cycles of carbon, nitrogen, sulphur and other important elements within arid lands. To further understand these types of ecosystems, the physicochemical and biological properties of Sidi Ameur and Himalatt Salt Lakes in the Algerian Sahara were examined and compared. Both lakes were relatively neutral in pH (7.2 to 7.4) and high in salt, at 12% and 20 % (w/v) salinity for Himalatt and Sidi Ameur Lakes, respectively, with dominant ions of sodium and chloride. The community compositions of microbes from all three domains (Bacteria, Archaea and Eukarya) were surveyed through the use of 16S and 18S ribosomal gene amplification and clone library clustering using amplified ribosomal DNA restriction analysis (ARDRA) in conjunction with DNA sequencing and analysis. A high level of microbial diversity, particularly among the bacteria of the Himalatt Salt Lake and archaea of Sidi Ameur Lake, was found within these environments. Representatives from all known halophilic bacterial phyla as well as 6 different genera of halophilic archaea were identified. Moreover, several apparently novel phylotypes among both archaea and bacteria were revealed.

  20. Mineralogy and Microbial Diversity of the Microbialites in the Hypersaline Storr's Lake, the Bahamas.

    Science.gov (United States)

    Paul, Varun G; Wronkiewicz, David J; Mormile, Melanie R; Foster, Jamie S

    2016-04-01

    Microbialites found in the low-light-intensity, hypersaline waters of Storr's Lake (SL), San Salvador Island, the Bahamas, were investigated with respect to their morphology, mineralogy, and microbial diversity. Previously described microbialite morphologies, as well as a newly identified "multi-cuspate" morphology, were observed at various depths. Electron microscopy analysis revealed the presence of angular, blocky, and needle-shaped crystals with mineralized cyanobacterial filaments and remains of exopolymeric substances. X-ray diffraction studies confirmed the presence of both Mg-calcite and aragonite in the plateau-mushroom and pinnacle mound microbialites, whereas only Mg-calcite was identified in the other microbialite morphotypes. A comprehensive molecular analysis using barcoded pyrosequencing of five different microbial mat communities identified at least 12 dominant bacterial phyla. Cyanobacteria were generally low in abundance and ranged from ∼0.01% in the deeper pinnacle mounds to ∼3.2% in the shallow calcareous knobs. Other photosynthetic members included green nonsulfur bacteria of the phylum Chloroflexi and purple sulfur bacteria of the class Gammaproteobacteria. All mat types contained significant amounts of sulfate-reducing and dehalogenating bacteria. The low light intensity reaching the deeper microbialites, the lack of dominant cyanobacteria, and the abundance of sulfate reducers and Chloroflexi collectively suggest that sulfate reduction and anoxygenic photosynthetic processes influence the carbonate biomineralization process in these systems.

  1. Microbial weeds in hypersaline habitats: the enigma of the weed-like Haloferax mediterranei

    Science.gov (United States)

    Oren, Aharon; Hallsworth, John E.

    2014-10-01

    Heterotrophic prokaryotic communities that inhabit saltern crystallizer ponds are typically dominated by two species, the archaeon Haloquadratum walsbyi and the bacterium Salinibacter ruber, regardless of location. These organisms behave as 'microbial weeds' as defined by Cray et al. (Microb Biotechnol6: 453–492, 2013) that possess the biological traits required to dominate the microbiology of these open habitats. Here, we discuss the enigma of the less abundant Haloferax mediterranei, an archaeon that grows faster than any other, comparable extreme halophile. It has a wide window for salt tolerance, can grow on simple as well as on complex substrates and degrade polymeric substances, has different modes of anaerobic growth, can accumulate storage polymers, produces gas vesicles, and excretes halocins capable of killing other Archaea. Therefore, Hfx. mediterranei is apparently more qualified as a 'microbial weed' than Haloquadratum and Salinibacter. However, the former differs because it produces carotenoid pigments only in the lower salinity range and lacks energy-generating retinal-based, light-driven ion pumps such as bacteriorhodopsin and halorhodopsin. We discuss these observations in relation to microbial weed biology in, and the open-habitat ecology of, hypersaline systems.

  2. Electricity generation by anaerobic bacteria and anoxic sediments from hypersaline soda lakes

    Science.gov (United States)

    Miller, L.G.; Oremland, R.S.

    2008-01-01

    Anaerobic bacteria and anoxic sediments from soda lakes produced electricity in microbial fuel cells (MFCs). No electricity was generated in the absence of bacterial metabolism. Arsenate respiring bacteria isolated from moderately hypersaline Mono Lake (Bacillus selenitireducens), and salt-saturated Searles Lake, CA (strain SLAS-1) oxidized lactate using arsenate as the electron acceptor. However, these cultures grew equally well without added arsenate using the MFC anode as their electron acceptor, and in the process oxidized lactate more efficiently. The decrease in electricity generation by consumption of added alternative electron acceptors (i.e. arsenate) which competed with the anode for available electrons proved to be a useful indicator of microbial activity and hence life in the fuel cells. Shaken sediment slurries from these two lakes also generated electricity, with or without added lactate. Hydrogen added to sediment slurries was consumed but did not stimulate electricity production. Finally, electricity was generated in statically incubated "intact" sediment cores from these lakes. More power was produced in sediment from Mono Lake than from Searles Lake, however microbial fuel cells could detect low levels of metabolism operating under moderate and extreme conditions of salt stress. ?? 2008 US Government.

  3. Primary and heterotrophic productivity relate to multikingdom diversity in a hypersaline mat.

    Science.gov (United States)

    Bernstein, Hans C; Brislawn, Colin J; Dana, Karl; Flores-Wentz, Tobias; Cory, Alexandra B; Fansler, Sarah J; Fredrickson, James K; Moran, James J

    2017-10-01

    Benthic microbial ecosystems are widespread yet knowledge gaps still remain on the relationships between the diversity of species across kingdoms and productivity. Here, we ask two fundamental questions: (i) How does species diversity relate to the rates of primary and heterotrophic productivity? (ii) How do diel variations in light-energy inputs influence productivity and microbiome diversity? To answer these questions, microbial mats from a magnesium sulfate hypersaline lake were used to establish microcosms. Both the number and relatedness between bacterial and eukaryotic taxa in the microbiome were assayed via amplicon-based sequencing of 16S and 18S rRNA genes over two diel cycles. These results correlated with biomass productivity obtained from substrate-specific 13C stable isotope tracers that enabled comparisons between primary and heterotrophic productivity. Both bacterial and eukaryotic species richness and evenness were related only to the rates of 13C-labeled glucose and acetate biomass incorporation. Interestingly, measures of these heterotrophic relationships changed from positive and negative correlations depending on carbon derived from glucose or acetate, respectively. The bacterial and eukaryotic diversity of this ecosystem is also controlled, in part, from energy constraints imposed by changing irradiance over a diel cycle. © FEMS 2017.

  4. Spatial distribution of Chloroflexus-like bacteria in the hypersaline artificial microbial mat

    Science.gov (United States)

    Bachar, A.; Polerecky, L.; Vamvakopoulos, K.; de Beer, D.; Jonkers, H. M.

    An artificial microbial mat grown in a mesocosm originated from the Hypersaline Lake of La Salada de Chiprana NE Spain was examined with respect to its organism s spatial distribution via high resolution methods A special attention was given to the elucidative Chloroflexus -like bacteria on which spatial distribution data is not available We have characterized this thick 1cm and developed mat for photopigments HPLC and obtained the general pigment distribution pattern Furthermore fiberoptic and photosynthetic microsensor measurements gave inner light attenuations and flux rates of oxygen within the different layers respectively Using fluorescence and spectral imaging we were able to detect characteristic pigmentation in the different layers FISH probes targeting Chloroflexus -like bacteria confirmed the visualization techniques and showed a single hybridized layer below the cyanobacterial layer as did the HPLC fiberoptic microsensor and fluorescence imaging We conclude that Chloroflexus -like bacteria are located below the cyanobacterial layer and above the purple sulfur bacteria and for the firs time we are able to show it by different independent state of the art techniques These approaches can be important for rapid community investigations within a millimeter scale microniches

  5. Contribution of Chloroflexus respiration to oxygen cycling in a hypersaline microbial mat from Lake Chiprana, Spain.

    Science.gov (United States)

    Polerecky, Lubos; Bachar, Ami; Schoon, Raphaela; Grinstein, Mor; Jørgensen, Bo Barker; de Beer, Dirk; Jonkers, Henk M

    2007-08-01

    In dense stratified systems such as microbial mats, photosynthesis and respiration are coupled due to a tight spatial overlap between oxygen-producing and -consuming microorganisms. We combined microsensors and a membrane inlet mass spectrometer with two independent light sources emitting in the visible (VIS) and near infrared (NIR) regions to study this coupling in more detail. Using this novel approach, we separately quantified the activity of the major players in the oxygen cycle in a hypersaline microbial mat: gross photosynthesis of cyanobacteria, NIR light-dependent respiration of Chloroflexus-like bacteria (CLB) and respiration of aerobic heterotrophs. Illumination by VIS light induced oxygen production in the top approximately 1 mm of the mat. In this zone CLB were found responsible for all respiration, while the contribution of the aerobic heterotrophs was negligible. Additional illumination of the mat with saturating NIR light completely switched off CLB respiration, resulting in zero respiration in the photosynthetically active zone. We demonstrate that microsensor-based quantification of gross and net photosyntheses in dense stratified systems should carefully consider the NIR light-dependent behaviour of CLB and other anoxygenic phototrophic groups.

  6. Benthic microbial production of oxygen supersaturates the bottom water of a stratified hypersaline lake.

    Science.gov (United States)

    Burke, C M

    1995-03-01

    Lake Hayward is a hypersaline lake that stratifies seasonally and maintains oxygen supersaturation in its bottom water for about 6 months each year. This phenomenon was found to be the result of photosynthesis by the benthic microbial communities, composed primarily of the cyanobacteria Cyanothece spp., Spirulina sp., and Oscillatoria sp. When these communities were present and the lake was stratified, the bottom water was supersaturated with oxygen (up to 370%). During illumination, the benthic microbial communities rapidly developed very high concentrations (e.g., >500 μM) of oxygen, which then diffused into the overlying water. However, while the overlying water became supersaturated, the concentration in the water was lower than in the benthic microbial communities because (1) transport across the sediment-water interface was limited by diffusion, and (2) turbulence rapidly mixed the oxygen throughout the much larger volume of the bottom water (approximately 1.5 m deep). Thus, import of oxygen by the benthic microbial communities at night proceeded more slowly than daytime export, allowing supersaturation of the bottom water to develop.

  7. Sequence analysis of an Archaeal virus isolated from a hypersaline lake in Inner Mongolia, China

    Science.gov (United States)

    Pagaling, Eulyn; Haigh, Richard D; Grant, William D; Cowan, Don A; Jones, Brian E; Ma, Yanhe; Ventosa, Antonio; Heaphy, Shaun

    2007-01-01

    Background We are profoundly ignorant about the diversity of viruses that infect the domain Archaea. Less than 100 have been identified and described and very few of these have had their genomic sequences determined. Here we report the genomic sequence of a previously undescribed archaeal virus. Results Haloarchaeal strains with 16S rRNA gene sequences 98% identical to Halorubrum saccharovorum were isolated from a hypersaline lake in Inner Mongolia. Two lytic viruses infecting these were isolated from the lake water. The BJ1 virus is described in this paper. It has an icosahedral head and tail morphology and most likely a linear double stranded DNA genome exhibiting terminal redundancy. Its genome sequence has 42,271 base pairs with a GC content of ~65 mol%. The genome of BJ1 is predicted to encode 70 ORFs, including one for a tRNA. Fifty of the seventy ORFs had no identity to data base entries; twenty showed sequence identity matches to archaeal viruses and to haloarchaea. ORFs possibly coding for an origin of replication complex, integrase, helicase and structural capsid proteins were identified. Evidence for viral integration was obtained. Conclusion The virus described here has a very low sequence identity to any previously described virus. Fifty of the seventy ORFs could not be annotated in any way based on amino acid identities with sequences already present in the databases. Determining functions for ORFs such as these is probably easier using a simple virus as a model system. PMID:17996081

  8. Deadly Poisonous Turkish Mushrooms Containing Alpha Amanitin

    Directory of Open Access Journals (Sweden)

    Ilgaz Akata

    2015-10-01

    Full Text Available Mushroom poisoning is still a serious health problem for Turkey. The mushroom species which cause fatal mushroom poisoning have been reported to contain at least 98% alpha-amanitin. The knowledge of the poisonous mushroom species including alpha- amanitin is important for the treatment and prevention of these poisonings. In this review, the mushrooms containig alpha-amanitin and causing deadly mushroom poisinings were listed and given information about their poisonus effects. According to literature, nine poisonous mushroom species which include alpha-amanitin have so far been reported from Turkey. These are Lepiota brunneoincarnata; Lepiota castanea; Lepiota helveola; Lepiota subincarnata; Amanita phalloides; Amanita verna; Amanita virosa; Conocybe filaris and Galerina marginata.

  9. Dead time corrections using the backward extrapolation method

    Energy Technology Data Exchange (ETDEWEB)

    Gilad, E., E-mail: gilade@bgu.ac.il [The Unit of Nuclear Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Dubi, C. [Department of Physics, Nuclear Research Center NEGEV (NRCN), Beer-Sheva 84190 (Israel); Geslot, B.; Blaise, P. [DEN/CAD/DER/SPEx/LPE, CEA Cadarache, Saint-Paul-les-Durance 13108 (France); Kolin, A. [Department of Physics, Nuclear Research Center NEGEV (NRCN), Beer-Sheva 84190 (Israel)

    2017-05-11

    Dead time losses in neutron detection, caused by both the detector and the electronics dead time, is a highly nonlinear effect, known to create high biasing in physical experiments as the power grows over a certain threshold, up to total saturation of the detector system. Analytic modeling of the dead time losses is a highly complicated task due to the different nature of the dead time in the different components of the monitoring system (e.g., paralyzing vs. non paralyzing), and the stochastic nature of the fission chains. In the present study, a new technique is introduced for dead time corrections on the sampled Count Per Second (CPS), based on backward extrapolation of the losses, created by increasingly growing artificially imposed dead time on the data, back to zero. The method has been implemented on actual neutron noise measurements carried out in the MINERVE zero power reactor, demonstrating high accuracy (of 1–2%) in restoring the corrected count rate. - Highlights: • A new method for dead time corrections is introduced and experimentally validated. • The method does not depend on any prior calibration nor assumes any specific model. • Different dead times are imposed on the signal and the losses are extrapolated to zero. • The method is implemented and validated using neutron measurements from the MINERVE. • Result show very good correspondence to empirical results.

  10. Quantifying carbon stores and decomposition in dead wood: A review

    Science.gov (United States)

    Matthew B. Russell; Shawn Fraver; Tuomas Aakala; Jeffrey H. Gove; Christopher W. Woodall; Anthony W. D’Amato; Mark J. Ducey

    2015-01-01

    The amount and dynamics of forest dead wood (both standing and downed) has been quantified by a variety of approaches throughout the forest science and ecology literature. Differences in the sampling and quantification of dead wood can lead to differences in our understanding of forests and their role in the sequestration and emissions of CO2, as...

  11. Day of the Dead: A Mexican-American Celebration.

    Science.gov (United States)

    Hoyt-Goldsmith, Diane

    This children's book describes how a Mexican-American family celebrates the traditional Mexican holiday, Day of the Dead (Dia de Muertos). The book centers on 10-year-old twins, Ximena and Azucena, who live in Sacramento, California, with their two brothers, older sister, and parents. The Day of the Dead takes place on the first and second day of…

  12. 37 CFR 1.42 - When the inventor is dead.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false When the inventor is dead. 1.42 Section 1.42 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... for A Patent § 1.42 When the inventor is dead. In case of the death of the inventor, the legal...

  13. 37 CFR 1.422 - When the inventor is dead.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false When the inventor is dead. 1.422 Section 1.422 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... File An International Application § 1.422 When the inventor is dead. In case of the death of the...

  14. COMPARATIVE ANALYSIS OF TECHNILOGIES OF CHITOSAN PRODUCTION FROM DEAD BEES

    Directory of Open Access Journals (Sweden)

    Marina Abramova

    2017-07-01

    Full Text Available Objective: The aim of this work is to study the characteristics of technology of chitosan obtaining from unconventional sources, namely from dead bees. Methods: The article considers three methods of chitosan obtaining from dead bees, namely the technology with the usage of dead bees with low degree of drying; the technology with the usage of dead bees with high degree of drying; the technology with the usage of dead bees with high degree of drying but without separation of deproteination and deacetylation stages. Results: It is proved that the technology with the usage of dead bees with high degree of drying but without separation of deproteination and deacetylation stages does not require high temperatures and long time. Yield of chitosan with the use of this technology is 21-24%. Discussion: The expediency of dead bees usage as raw material for the production of chitosan in Ukraine is shown. The technologies of chitosan obtaining from dead bees are compared, the most efficient one is chosen, which provide the highest yield of the finished product, so it is the most promising for the application in practice.

  15. Recipe for Hypoxia: Playing the Dead Zone Game

    Science.gov (United States)

    Kastler, Jessica A.

    2009-01-01

    Dead zones--areas experiencing low levels of dissolved oxygen--are growing in shallow ocean waters around the world. Research has shown that dead zones form as a result of a specific type of pollution, called nutrient enrichment or eutrophication, and are found in almost every coastal zone where humans have large populations. Concepts related to…

  16. Dead wood inventory and assessment in South Korea

    Science.gov (United States)

    Jong-Su Yim; Rae Hyun Kim; Sun-Jeong Lee; Yeongmo. Son

    2015-01-01

    Dead wood (DW) plays a critical role not only in maintaining biodiversity but also in stocking carbon under UNFCCC. From the 5th national forest inventory (NFI5; 2006-2010) in South Korea, field data relevant to the DW including standing and downed dead trees by four decay class, etc. were collected. Based on the NFI5 data,...

  17. 9 CFR 314.8 - Dead animal carcasses.

    Science.gov (United States)

    2010-01-01

    ... received with livestock for slaughter at an official establishment, no dead animal or part of the carcass... circumstances shall the carcasses of any animal which has died otherwise than by slaughter, or any part thereof... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Dead animal carcasses. 314.8 Section...

  18. Modeling and clinical diagnosis of dead regions in the cochlea

    NARCIS (Netherlands)

    Warnaar, B.

    2013-01-01

    This thesis attempts to establish, using a model framework, a relationship between the psychophysical measurement of off-frequency listening and the functional auditory loss caused by dead regions in the cochlear. The results are used to evaluate the clinical value of dead region diagnosis with PTCs

  19. Exploration of microbial diversity and community structure of Lonar Lake: the only hypersaline meteorite crater lake within basalt rock

    Directory of Open Access Journals (Sweden)

    Dhiraj ePaul

    2016-01-01

    Full Text Available Lonar Lake is a hypersaline and hyperalkaline soda lake and the only meteorite impact crater in the world created in the basalt rocks. Although culture-dependent studies have been reported, the comprehensive understanding of microbial community composition and structure of Lonar Lake remain obscure. In the present study, microbial community structure associated with Lonar Lake sediment and water samples was investigated using high throughput sequencing. Microbial diversity analysis revealed the existence of diverse, yet near consistent community composition. The predominance of bacterial phyla Proteobacteria (30% followed by Actinobacteria (24%, Firmicutes (11% and Cyanobacteria (5% was observed. Bacterial phylum Bacteroidetes (1.12%, BD1-5 (0.5%, Nitrospirae (0.41% and Verrucomicrobia (0.28% were detected as relatively minor populations in Lonar Lake ecosystem. Within Proteobacteria, Gammaproteobacteria represented the most abundant population (21-47% among all the sediments and as a minor population in water samples. Bacterial members Proteobacteria and Firmicutes were present significantly higher (p≥0.05 in sediment samples, whereas members of Actinobacteria, Candidate_division_TM7 and Cyanobacteria (p≥0.05 were significantly abundant in water samples. It was noted that compared to other hypersaline soda lakes, Lonar Lake samples formed one distinct cluster, suggesting a different microbial community composition and structure. The present study reports for the first time the different composition of indigenous microbial communities between the sediment and water samples of Lonar Lake. Having better insight of community structure of this Lake ecosystem could be useful in understanding the microbial role in the geochemical cycle for future functional exploration of the unique hypersaline Lonar Lake.

  20. Responses of the Mediterranean seagrass Posidonia oceanica to hypersaline stress duration and recovery.

    Science.gov (United States)

    Marín-Guirao, Lázaro; Sandoval-Gil, Jose Miguel; Bernardeau-Esteller, Jaime; Ruíz, Juan Manuel; Sánchez-Lizaso, Jose Luis

    2013-03-01

    We studied the hypersaline stress responses of the Mediterranean seagrass Posidonia oceanica to determine if the species was tolerant to salinity increases that occur in coastal waters by the desalination industry. Water relations, amino acids, carbohydrates, ions, photosynthesis, respiration, chlorophyll a fluorescence, leaf growth and morphology, and plant mortality were analysed after exposing the mesocosm P. oceanica to a salinity level of 43 for one and three months followed by a month for recovery. One-month saline-stressed plants exhibited sub-lethal effects, including a leaf cell turgor pressure reduction, loss of ionic equilibrium and decreased leaf growth. There were also changes in photoprotective mechanisms, increased concentrations of organic osmolytes in leaves and reduced leaf ageing. All these dysfunctions recovered after removing the stress. After the longer exposure of three months, stress symptoms were much more acute and plants showed an excessive ionic exclusion capacity, increased leaf cell turgor, reduced plant carbon balance, increased leaf aging and leaf decay and increased plant mortality, which indicated that the plant had entered a stage of severe physiological stress. In addition, the long-term saline-stressed plants were not able to recover, still showing sustained injury after the one-month recovery period as reflected by unbalanced leaf ionic content, persistently impaired photosynthesis, decline in internal carbon resources and decreased leaf growth that resulted in undersized plants. In conclusion, P. oceanica was not able to acclimate to the saline conditions tested since it could not reach a new physiological equilibrium or recover after a chronic exposure of 3 months. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Unexpected Diversity and Complexity of the Guerrero Negro Hypersaline Microbial Mat

    Science.gov (United States)

    Ley, Ruth E.; Harris, J. Kirk; Wilcox, Joshua; Spear, John R.; Miller, Scott R.; Bebout, Brad M.; Maresca, Julia A.; Bryant, Donald A.; Sogin, Mitchell L.; Pace, Norman R.

    2006-01-01

    We applied nucleic acid-based molecular methods, combined with estimates of biomass (ATP), pigments, and microelectrode measurements of chemical gradients, to map microbial diversity vertically on a millimeter scale in a hypersaline microbial mat from Guerrero Negro, Baja California Sur, Mexico. To identify the constituents of the mat, small-subunit rRNA genes were amplified by PCR from community genomic DNA extracted from layers, cloned, and sequenced. Bacteria dominated the mat and displayed unexpected and unprecedented diversity. The majority (1,336) of the 1,586 bacterial 16S rRNA sequences generated were unique, representing 752 species (≥97% rRNA sequence identity) in 42 of the main bacterial phyla, including 15 novel candidate phyla. The diversity of the mat samples differentiated according to the chemical milieu defined by concentrations of O2 and H2S. Bacteria of the phylum Chloroflexi formed the majority of the biomass by percentage of bulk rRNA and of clones in rRNA gene libraries. This result contradicts the general belief that cyanobacteria dominate these communities. Although cyanobacteria constituted a large fraction of the biomass in the upper few millimeters (>80% of the total rRNA and photosynthetic pigments), Chloroflexi sequences were conspicuous throughout the mat. Filamentous Chloroflexi bacteria were identified by fluorescence in situ hybridization within the polysaccharide sheaths of the prominent cyanobacterium Microcoleus chthonoplastes, in addition to free living in the mat. The biological complexity of the mat far exceeds that observed in other polysaccharide-rich microbial ecosystems, such as the human and mouse distal guts, and suggests that positive feedbacks exist between chemical complexity and biological diversity. PMID:16672518

  2. Rapid instrument prototyping with open source hardware and software: Application to water quality in hypersaline estuaries.

    Science.gov (United States)

    Loose, B.; O'Shea, R.

    2016-02-01

    We describe the design and deployment of a water quality sonde that utilizes mobile phone networks for near-real time data telemetry. The REOL or Realtime Estuary Ocean Logger has the unique and valuable capability of logging data internally and simultaneously relaying the information to a webserver using a cellular modem. The internal circuitry consists of a GSM cellular modem, a microcontroller, and an SD card for data storage - these components are low cost, and backed up with circuit diagrams and programming libraries that are published under open source license. This configuration is versatile and is capable of reading instrument output from a broad spectrum of devices, including serial, TTL, analog voltage (0 - 5V), and analog current (typically 4-20 mA). We find the greatest challenges lie in development of smart software that is capable of handling the conditions brought on by this harsh environment. We have programmed the sonde to first determine whether it is submerged by water, and record the temperature on the electronics before deciding whether to telemeter measurements over the cellular network. The Google App EngineTM provides an interactive visualization platform. We have tested the REOL with a variety of water quality sensors. In the configuration described here, we use a thermistor, depth gauge and torroidal conductivity sensor to measure water temperature, water level and conductivity up to 200 mS/cm. The latter is necessary for studies in hypersaline estuaries, where porewater salinity can exceed 100 g/kg. We present data from two estuaries in West Africa and from a longer-term deployment in the Narragansett Bay, Rhode Island.

  3. Distribution of picophytoplankton communities from brackish to hypersaline waters in a South Australian coastal lagoon.

    Science.gov (United States)

    Schapira, Mathilde; Buscot, Marie-Jeanne; Pollet, Thomas; Leterme, Sophie C; Seuront, Laurent

    2010-02-24

    Picophytoplankton (i.e. cyanobacteria and pico-eukaryotes) are abundant and ecologically critical components of the autotrophic communities in the pelagic realm. These micro-organisms colonized a variety of extreme environments including high salinity waters. However, the distribution of these organisms along strong salinity gradient has barely been investigated. The abundance and community structure of cyanobacteria and pico-eukaryotes were investigated along a natural continuous salinity gradient (1.8% to 15.5%) using flow cytometry. Highest picophytoplankton abundances were recorded under salinity conditions ranging between 8.0% and 11.0% (1.3 x 106 to 1.4 x 106 cells ml-1). Two populations of picocyanobacteria (likely Synechococcus and Prochlorococcus) and 5 distinct populations of pico-eukaryotes were identified along the salinity gradient. The picophytoplankton cytometric-richness decreased with salinity and the most cytometrically diversified community (4 to 7 populations) was observed in the brackish-marine part of the lagoon (i.e. salinity below 3.5%). One population of pico-eukaryote dominated the community throughout the salinity gradient and was responsible for the bloom observed between 8.0% and 11.0%. Finally only this halotolerant population and Prochlorococcus-like picocyanobacteria were identified in hypersaline waters (i.e. above 14.0%). Salinity was identified as the main factor structuring the distribution of picophytoplankton along the lagoon. However, nutritive conditions, viral lysis and microzooplankton grazing are also suggested as potentially important players in controlling the abundance and diversity of picophytoplankton along the lagoon. The complex patterns described here represent the first observation of picophytoplankton dynamics along a continuous gradient where salinity increases from 1.8% to 15.5%. This result provides new insight into the distribution of pico-autotrophic organisms along strong salinity gradients and allows for a

  4. Assessment of the trophic state of a hypersaline-carbonatic environment: Vermelha Lagoon (Brazil).

    Science.gov (United States)

    Laut, Lazaro; Martins, Maria Virginia Alves; Frontalini, Fabrizio; Ballalai, João M; Belart, Pierre; Habib, Renan; Fontana, Luiz F; Clemente, Iara M M M; Lorini, Maria Lucia; Mendonça Filho, João G; Laut, Vanessa M; Figueiredo, Marcos de Souza Lima

    2017-01-01

    Vermelha Lagoon is a hypersaline shallow transitional ecosystem in the state of Rio de Janeiro (Brazil). This lagoon is located in the protected area of Massambaba, between the cities of Araruama and Saquarema (Brazil), and displays two quite uncommon particularities: it exhibits carbonate sedimentation and displays the development of Holocene stromatolites. Due to both particularities, the salt industry and property speculation have been, increasingly, generating anthropic pressures on this ecosystem. This study aims to apply a multiproxy approach to evaluate the trophic state of Vermelha Lagoon based on physicochemical parameters and geochemical data for the quantification and qualification of organic matter (OM), namely total organic carbon (TOC), total sulfur (TS), total phosphorus (TP) and biopolymeric carbon (BPC), including carbohydrates (CHO), lipids (LIP) and proteins (PTN). The CHO/TOC ratio values suggest that OM supplied to the sediment is of autochthonous origin and results, essentially, from microbial activity. The cluster analyses allowed the identification of four regions in Vermelha Lagoon. The Region I included stations located in shallow areas of the eastern sector of Vermelha lagoon affected by the impact of the artificial channel of connection with Araruama Lagoon. The Region II, under the influence of salt pans, is characterized by the highest values of BPC, namely CHO promoted by microbiological activity. The Region III include stations spread through the lagoon with high values of dissolved oxygen and lower values of TP. Stromatolites and microbial mattes growth was observed in some stations of this sector. Region IV, where the highest values of TOC and TS were found, represents depocenters of organic matter, located in general in depressed areas. Results of this work evidences that the Vermelha Lagoon is an eutrophic but alkaline and well oxygenated environment (at both water column and surface sediment) where the autotrophic activity is

  5. Fermentation couples Chloroflexi and sulfate-reducing bacteria to Cyanobacteria in hypersaline microbial mats

    Directory of Open Access Journals (Sweden)

    Jackson Z Lee

    2014-02-01

    Full Text Available Past studies of hydrogen cycling in hypersaline microbial mats have shown an active nighttime cycle, with production largely from Cyanobacteria and consumption from sulfate-reducing bacteria (SRB. However, the mechanisms and magnitude of hydrogen cycling have not been extensively studied. Two mats types near Guerrero Negro, Mexico -- permanently submerged Microcoleus microbial mats (GN-S, and intertidal Lyngbya microbial mats (GN-I -- were used in microcosm diel manipulation experiments with 3-(3,4-dichlorophenyl-1,1-dimethylurea (DCMU, molybdate, ammonium addition, and physical disruption to understand the processes responsible for hydrogen cycling between mat microbes. Across microcosms, H2 production occurred under dark anoxic conditions with simultaneous production of a suite of organic acids. H2 production was not significantly affected by inhibition of nitrogen fixation, but rather appears to result from constitutive fermentation of photosynthetic storage products by oxygenic phototrophs. Comparison to accumulated glycogen and to CO2 flux indicated that, in the GN-I mat, fermentation released almost all of the carbon fixed via photosynthesis during the preceding day, primarily as organic acids. Across mats, although oxygenic and anoxygenic phototrophs were detected, cyanobacterial [NiFe]-hydrogenase transcripts predominated. Molybdate inhibition experiments indicated that SRBs from a wide distribution of dsrA phylotypes were responsible for H2 consumption. Incubation with 13C-acetate and nanoSIMS (secondary ion mass-spectrometry indicated higher uptake in both Chloroflexi and SRBs relative to other filamentous bacteria. These manipulations and diel incubations confirm that Cyanobacteria were the main fermenters in Guerrero Negro mats and that the net flux of nighttime fermentation byproducts (not only hydrogen was largely regulated by the interplay between Cyanobacteria, SRBs, and Chloroflexi.

  6. Microbial communities inhabiting hypersaline microbial mats from the Abu Dhabi sabkha

    Science.gov (United States)

    Andrade, Luiza; Dutton, Kirsten; Paul, Andreas; van der Land, Cees; Sherry, Angela; Lokier, Stephen; Head, Ian

    2017-04-01

    Microbial mats are organo-sedimentary structures that are typically found in areas with extreme environmental conditions. Since these ecosystems are considered to be representative of the oldest forms of life on Earth, the study of microbial mats can inform our understanding of the development of life early in the history of our planet. In this study, we used hypersaline microbial mats from the Abu Dhabi sabkha (coastal salt flats). Cores of microbial mats (ca. 90 mm depth) were collected within an intertidal region. The cores were sliced into layers 2-3 mm thick and genomic DNA was extracted from each layer. A fragment of the 16S rRNA encoding gene was amplified in all DNA extracts, using barcoded primers, and the amplicons sequenced with the Ion Torrent platform to investigate the composition of the microbial communities down the depth of the cores. Preliminary results revealed a high proportion of Archaea (15.5-40.8% abundance) in all layers, with Halobacteria appearing to be more significant in the first 40 mm (0.4-10.3% of the total microbial community). Members of the Deltaproteobacteria were dominant in almost all layers of the microbial mat (≤ 48.6% relative abundance); however this dominance was not reflected in the first 8 mm, where the abundance was less than 2%. Chloroflexi and Anaerolinea, representing 93% of bacterial abundance, dominated the first 8 mm depth and decreased at greater depth (≤ 3% relative abundance). Cyanobacteria were found only in the top 10 mm, with unexpected low abundance (≤ 3% of the total number of reads). These results show a vertical zonation of microbial communities and processes in the microbial mats. Further analyses are underway to investigate if these patterns are repeated at other sites along a transect of the sabkha, and to relate the microbial composition to the physical-chemical conditions of the sites.

  7. Assessment of the trophic state of a hypersaline-carbonatic environment: Vermelha Lagoon (Brazil.

    Directory of Open Access Journals (Sweden)

    Lazaro Laut

    Full Text Available Vermelha Lagoon is a hypersaline shallow transitional ecosystem in the state of Rio de Janeiro (Brazil. This lagoon is located in the protected area of Massambaba, between the cities of Araruama and Saquarema (Brazil, and displays two quite uncommon particularities: it exhibits carbonate sedimentation and displays the development of Holocene stromatolites. Due to both particularities, the salt industry and property speculation have been, increasingly, generating anthropic pressures on this ecosystem. This study aims to apply a multiproxy approach to evaluate the trophic state of Vermelha Lagoon based on physicochemical parameters and geochemical data for the quantification and qualification of organic matter (OM, namely total organic carbon (TOC, total sulfur (TS, total phosphorus (TP and biopolymeric carbon (BPC, including carbohydrates (CHO, lipids (LIP and proteins (PTN. The CHO/TOC ratio values suggest that OM supplied to the sediment is of autochthonous origin and results, essentially, from microbial activity. The cluster analyses allowed the identification of four regions in Vermelha Lagoon. The Region I included stations located in shallow areas of the eastern sector of Vermelha lagoon affected by the impact of the artificial channel of connection with Araruama Lagoon. The Region II, under the influence of salt pans, is characterized by the highest values of BPC, namely CHO promoted by microbiological activity. The Region III include stations spread through the lagoon with high values of dissolved oxygen and lower values of TP. Stromatolites and microbial mattes growth was observed in some stations of this sector. Region IV, where the highest values of TOC and TS were found, represents depocenters of organic matter, located in general in depressed areas. Results of this work evidences that the Vermelha Lagoon is an eutrophic but alkaline and well oxygenated environment (at both water column and surface sediment where the autotrophic

  8. Natronoarchaeum persicum sp. nov., a haloarchaeon isolated from a hypersaline lake.

    Science.gov (United States)

    Naghoni, Ali; Emtiazi, Giti; Amoozegar, Mohammad Ali; Rasooli, Mehrnoosh; Etemadifar, Zahra; Shahzadeh Fazeli, Seyed Abolhassan; Minegishi, Hiroaki; Ventosa, Antonio

    2017-09-01

    A novel halophilic archaeon, designated strain WIIAL99T, was isolated from Lake Meyghan, a hypersaline lake in Iran. Cells of strain WIIAL99T were non-motile, catalase-positive and oxidase-negative. Strain WIIAL99T required at least 2.5 M NaCl and 0.05 M MgCl2 for growth. Optimal growth was achieved at 3.5 M NaCl and 0.1 M MgCl2. The optimum pH and temperature for growth were pH 7.0 and 37-40 °C; it was able to grow at pH 6.0-8.5 and 20-55 °C. Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). The major polar lipids of strain WIIAL99T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, disulfated diglycosyl diether and one unidentified glycolipid. The DNA G+C content of strain WIIAL99T was 66.7 mol%. The closest relative was Natronoarchaeum rubrum JCM 17119T with 98.2 % similarity in the orthologous 16S rRNA gene sequence. Analysis of 16S rRNA and rpoB' gene sequences indicated that strain WIIAL99T is a member of the genus Natronoarchaeum in the family Halobacteriaceae and forms a distinct cluster. It was concluded that strain WIIAL99T (=IBRC-M 11062T=LMG 29814T) represents a novel species of the genus Natronoarchaeum, for which the name Natronoarchaeum persicum sp. nov. is proposed.

  9. Halorubrum persicum sp. nov., an extremely halophilic archaeon isolated from sediment of a hypersaline lake.

    Science.gov (United States)

    Corral, Paulina; de la Haba, Rafael R; Sánchez-Porro, Cristina; Amoozegar, Mohammad Ali; Papke, R Thane; Ventosa, Antonio

    2015-06-01

    An extremely halophilic archaeon belonging to the genus Halorubrum, strain C49T, was isolated from sediment of the hypersaline lake Aran-Bidgol in Iran. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that strain C49T was closely related to Halorubrum saccharovorum JCM 8865T (99.5 %) and other species of the genus Halorubrum. Studies based on multilocus sequence analysis revealed that strain C49T is placed among the species of Halorubrum; the strain constituted a defined branch in comparison with the type strains of species of Halorubrum, while the 16S rRNA gene sequence divergence could not define the status of the newly isolated strain. For optimum growth, strain C49T required 20 % (w/v) salts at pH 7.0 and 37 °C under aerobic conditions. Mg2+ was not required. The cells were pleomorphic rods, motile and stained Gram-variable. Colonies of the strain were pink. Hypotonic treatment with <12 % NaCl provoked cell lysis. The polar lipid pattern of strain C49T consisted of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester derived from both C20C20 and C20C25 archaeol, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. The DNA G+C content was 64.2 mol%. DNA-DNA hybridization studies and average nucleotide identity confirmed that strain C49T constitutes a distinct genospecies. Data obtained in this study show that strain C49T represents a novel species, for which the name Halorubrum persicum sp. nov. is proposed. The type strain is C49T ( = IBRC-M 10232T = JCM 30541T).

  10. Halorubrum halodurans sp. nov., an extremely halophilic archaeon isolated from a hypersaline lake.

    Science.gov (United States)

    Corral, Paulina; de la Haba, Rafael R; Sánchez-Porro, Cristina; Ali Amoozegar, Mohammad; Thane Papke, R; Ventosa, Antonio

    2016-01-01

    Two extremely halophilic archaea, strains Cb34T and C170, belonging to the genus Halorubrum, were isolated from the brine of the hypersaline lake Aran-Bidgol in Iran. Cells of the two strains were motile, pleomorphic rods, stained Gram-variable and produced red-pigmented colonies. Strains Cb34T and C170 required 25 % (w/v) salts, pH 7.0 and 37 °C for optimal growth under aerobic conditions; 0.3 M Mg2+ was required. Cells of both isolates were lysed in distilled water and hypotonic treatment with < 10 % NaCl provoked cell lysis. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that these two strains were closely related to Halorubrum cibi B31T (98.8 %) and other members of the genus Halorubrum. In addition, studies based on the rpoB' gene revealed that strains Cb34T and C170 are placed among the species of Halorubrum and are closely related to Halorubrum cibi B31T, with rpoB' gene sequence similarity less than or equal to 95.7 %. The polar lipid patterns of both strains consisted of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. The DNA G+C content was 62.1-62.4 mol%. DNA-DNA hybridization studies confirmed that strains Cb34T and C170 constitute a distinct species. Data obtained in this study show that the two strains represent a novel species, for which the name Halorubrum halodurans sp. nov. is proposed. The type strain is Cb34T ( = CECT 8745T = IBRC-M 10233T).

  11. Halovivax limisalsi sp. nov., an extremely halophilic archaeon from hypersaline mud.

    Science.gov (United States)

    Amoozegar, Mohammad Ali; Makhdoumi-Kakhki, Ali; Mehrshad, Maliheh; Riazi, Siavash; Ventosa, Antonio

    2014-10-01

    A Gram-stain-negative, cream-pigmented, motile, extremely halophilic archaeon, designated strain IC38(T), was isolated from a saline mud sample taken from a hypersaline lake, Aran-Bidgol, in Iran. The strain required at least 2.5 M NaCl for growth. However, MgCl2 was not required. Optimal growth occurred with 4.3 M NaCl and 0.2 M MgCl2. The optimum pH and temperature for growth were pH 7.0 and 35 °C, respectively, and strain IC38(T) was able to grow over a pH range of 6.5-9.0, and a temperature range of 25-45 °C. Analysis of the 16S rRNA gene sequence revealed that strain IC38(T) clustered with the two species of the genus Halovivax, Halovivax asiaticus EJ-46(T) and Halovivax ruber XH-70(T), with sequence similarities of 96.4% and 96.1%, respectively. The similarities between the rpoB' gene of the novel strain and Halovivax asiaticus and Halovivax ruber were 90.7% and 90.3%, respectively. The polar lipid pattern of strain IC38(T) consisted of phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester. Three unidentified glycolipids and two minor phospholipids were also observed. The DNA G+C content of strain IC38(T) was 62.6 mol%. On the basis of the phylogenetic analysis, as well as the biochemical and physiological characteristics, the new isolate is suggested to be a representative of a novel species of the genus Halovivax, for which the name Halovivax limisalsi sp. nov. is proposed. The type strain of Halovivax limisalsi is IC38(T) ( = IBRC-M 10022(T) = KCTC 4051(T)). © 2014 IUMS.

  12. Microbial diversity of the hypersaline and lithium-rich Salar de Uyuni, Bolivia.

    Science.gov (United States)

    Haferburg, Götz; Gröning, Janosch A D; Schmidt, Nadja; Kummer, Nicolai-Alexeji; Erquicia, Juan Carlos; Schlömann, Michael

    2017-06-01

    Salar de Uyuni, situated in the Southwest of the Bolivian Altiplano, is the largest salt flat on Earth. Brines of this athalassohaline hypersaline environment are rich in lithium and boron. Due to the ever- increasing commodity demand, the industrial exploitation of brines for metal recovery from the world's biggest lithium reservoir is likely to increase substantially in the near future. Studies on the composition of halophilic microbial communities in brines of the salar have not been published yet. Here we report for the first time on the prokaryotic diversity of four brine habitats across the salar. The brine is characterized by salinity values between 132 and 177 PSU, slightly acidic to near-neutral pH and lithium and boron concentrations of up to 2.0 and 1.4g/L, respectively. Community analysis was performed after sequencing the V3-V4 region of the 16S rRNA genes employing the Illumina MiSeq technology. The mothur software package was used for sequence processing and data analysis. Metagenomic analysis revealed the occurrence of an exclusively archaeal community comprising 26 halobacterial genera including only recently identified genera like Halapricum, Halorubellus and Salinarchaeum. Despite the high diversity of the halobacteria-dominated community in sample P3 (Shannon-Weaver index H'=3.12 at 3% OTU cutoff) almost 40% of the Halobacteriaceae-assigned sequences could not be classified on the genus level under stringent filtering conditions. Even if the limited taxonomic resolution of the V3-V4 region for halobacteria is considered, it seems likely to discover new, hitherto undescribed genera of the family halobacteriaceae in this particular habitat of Salar de Uyuni in future. Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. No Time for Dead Time: Use the Fourier Amplitude Differences to Normalize Dead-time-affected Periodograms

    Science.gov (United States)

    Bachetti, Matteo; Huppenkothen, Daniela

    2018-02-01

    Dead time affects many of the instruments used in X-ray astronomy, by producing a strong distortion in power density spectra. This can make it difficult to model the aperiodic variability of the source or look for quasi-periodic oscillations. Whereas in some instruments a simple a priori correction for dead-time-affected power spectra is possible, this is not the case for others such as NuSTAR, where the dead time is non-constant and long (∼2.5 ms). Bachetti et al. (2015) suggested the cospectrum obtained from light curves of independent detectors within the same instrument as a possible way out, but this solution has always only been a partial one: the measured rms was still affected by dead time because the width of the power distribution of the cospectrum was modulated by dead time in a frequency-dependent way. In this Letter, we suggest a new, powerful method to normalize dead-time-affected cospectra and power density spectra. Our approach uses the difference of the Fourier amplitudes from two independent detectors to characterize and filter out the effect of dead time. This method is crucially important for the accurate modeling of periodograms derived from instruments affected by dead time on board current missions like NuSTAR and Astrosat, but also future missions such as IXPE.

  14. Autopsies of the real: Resurrecting the dead

    Directory of Open Access Journals (Sweden)

    Valis, Noël

    2011-12-01

    Full Text Available The sense of the real, or the material—the dead body—as an inextricable part of the sacred does not disappear in the secular environment of the nineteenth and twentieth centuries. This article analyzes specific humanitarian narratives centered on the practice of autopsy and mummification, in which the traces of Catholicism act as a kind of spectral discourse of the imagination, where the real is configured in forms of the uncanny, the monstrous or the sacred.

    El sentido de lo real, de lo material —el cuerpo sin vida— como una inextricable parte de lo sagrado, no desaparece del ambiente secular de los siglos XIX y XX. En los relatos analizados en este artículo se estudia cómo en determinadas narrativas humanitarias centradas en la práctica de la autopsia y la momificación, las huellas del catolicismo actúan como una suerte de discurso espectral de la imaginación, en que lo real se configura en formas de lo siniestro, lo monstruoso o lo sagrado.

  15. Personal Identity and Resurrection from the Dead

    Directory of Open Access Journals (Sweden)

    Gasparov Igor

    2017-04-01

    Full Text Available The paper examines arguments of the “Christian materialist” Trenton Merricks that he provided in support of the claim that the Christian doctrine of resurrection from the dead is compatible with the materialist understanding of the nature of human beings. In his paper The Resurrection of the Body, Merricks discussed two aspects of the materialist interpretation of the traditional religious doctrine of the bodily resurrection. On the one hand, he analyses and tries to overcome objections against the possibility of the general resurrection in case the materialist understanding of the nature of human personality should be true (mainly the problem of the temporal gap. On the other hand, he provides some reasons why the materialist understanding of human nature is more relevant than its dualist counterpart to the doctrine of the bodily resurrection. The present paper evaluates his arguments and discusses the suggestion that the doctrine of resurrection is not only compatible with materialism, but is also tenable if human beings are identical with their physical bodies. The conclusion of the paper is that Merricks’ apologetic arguments achieve their aims in defending the doctrine of resurrection only partially; the resurrection doctrine appears more tenable if we accept the dualistic conception of human nature.

  16. Dead Time of Single Photon Avalanche Diodes

    Energy Technology Data Exchange (ETDEWEB)

    Neri, L., E-mail: lorenzo.neri@ct.infn.it [INFN Laboratori Nazionali del Sud, via S.Sofia 62, I-95125, Catania (Italy); Universita degli Studi di Catania, via S.Sofia 64, I-95123, Catania (Italy); Tudisco, S. [INFN Laboratori Nazionali del Sud, via S.Sofia 62, I-95125, Catania (Italy); Musumeci, F.; Scordino, A. [Universita degli Studi di Catania, via S.Sofia 64, I-95123, Catania (Italy); Fallica, G.; Mazzillo, M. [ST-Microelectronics, stradale Primosole 50, I-95100, Catania (Italy); Zimbone, M. [Universita degli Studi di Catania, via S.Sofia 64, I-95123, Catania (Italy)

    2011-06-15

    Single Photon Avalanche Diode (SPAD) is the new generation of Geiger-Muller counter device developed in semiconductor technology [S. Privitera et al. Sensors Journal, vol 8 Iss. 8 (2008) 4636; S. Tudisco et al. IEEE Sensors Journal vol 8 ISS 7-8 (2008) 1324; S. Cova et al. Applied Optics 35 (1996) 1956]. Physical dead time model and noise production process has been analyzed and their corrections have been performed [S.H. Lee, R.P. Gardner, M. Jae, Nucl. Instr. and Meth. in Phys. Res. B 263 (2007) 46]. We have been able to extract the real amount of incident photon rate up to 10{sup 7}cps using a device with 0.97{mu}s total deadtime. We also developed the equation of the noise count rate vs incoming photon rate, supported by Montecarlo simulation and experimental data. We marked the difference between dark rate and noise count rate, and introduced the noise rate inside the hybrid deadtime equation used for SPAD device.

  17. Quantifying Responses of Spectral Vegetation Indices to Dead Materials in Mixed Grasslands

    National Research Council Canada - National Science Library

    Yang, Xiaohui; Guo, Xulin

    2014-01-01

    ... by the confounding effects from external factors, such as soil properties, dead materials, and shadowing of vegetation canopies. Dead materials refer to the dead component of vegetation, including fallen...

  18. Do the 'brain dead' merely appear to be alive?

    Science.gov (United States)

    Nair-Collins, Michael; Miller, Franklin G

    2017-11-01

    The established view regarding 'brain death' in medicine and medical ethics is that patients determined to be dead by neurological criteria are dead in terms of a biological conception of death, not a philosophical conception of personhood, a social construction or a legal fiction. Although such individuals show apparent signs of being alive, in reality they are (biologically) dead, though this reality is masked by the intervention of medical technology. In this article, we argue that an appeal to the distinction between appearance and reality fails in defending the view that the 'brain dead' are dead. Specifically, this view relies on an inaccurate and overly simplistic account of the role of medical technology in the physiology of a 'brain dead' patient. We conclude by offering an explanation of why the conventional view on 'brain death', though mistaken, continues to be endorsed in light of its connection to organ transplantation and the dead donor rule. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  19. Dead pixel correction techniques for dual-band infrared imagery

    Science.gov (United States)

    Nguyen, Chuong T.; Mould, Nick; Regens, James L.

    2015-07-01

    We present two new dead pixel correction algorithms for dual-band infrared imagery. Specifically, we address the problem of repairing unresponsive elements in the sensor array using signal processing techniques to overcome deficiencies in image quality that are present following the nonuniformity correction process. Traditionally, dead pixel correction has been performed almost exclusively using variations of the nearest neighbor technique, where the value of the dead pixel is estimated based on pixel values associated with the neighboring image structure. Our approach differs from existing techniques, for the first time we estimate the values of dead pixels using information from both thermal bands collaboratively. The proposed dual-band statistical lookup (DSL) and dual-band inpainting (DIP) algorithms use intensity and local gradient information to estimate the values of dead pixels based on the values of unaffected pixels in the supplementary infrared band. The DSL algorithm is a regression technique that uses the image intensities from the reference band to estimate the dead pixel values in the band undergoing correction. The DIP algorithm is an energy minimization technique that uses the local image gradient from the reference band and the boundary values from the affected band to estimate the dead pixel values. We evaluate the effectiveness of the proposed algorithms with 50 dual-band videos. Simulation results indicate that the proposed techniques achieve perceptually and quantitatively superior results compared to existing methods.

  20. Salt resistance genes revealed by functional metagenomics from brines and moderate-salinity rhizosphere within a hypersaline environment

    Directory of Open Access Journals (Sweden)

    Salvador eMirete

    2015-10-01

    Full Text Available Hypersaline environments are considered one of the most extreme habitats on earth and microorganisms have developed diverse molecular mechanisms of adaptation to withstand these conditions. The present study was aimed at identifying novel genes involved in salt resistance from the microbial communities of brines and the rhizosphere from the Es Trenc saltern (Mallorca, Spain. The microbial diversity assessed by pyrosequencing of 16S rRNA gene libraries revealed the presence of communities that are typical in such environments. Metagenomic libraries from brine and rhizosphere samples, were transferred to the osmosensitive strain Escherichia coli MKH13, and screened for salt resistance. As a result, eleven genes that conferred salt resistance were identified, some encoding for well known proteins previously related to osmoadaptation as a glycerol and a proton pump, whereas others encoded for proteins not previously related to this function in microorganisms as DNA/RNA helicases, an endonuclease III (Nth and hypothetical proteins of unknown function. Furthermore, four of the retrieved genes were cloned and expressed in Bacillus subtilis and they also exhibited salt resistance in this bacterium, broadening the spectrum of bacterial species where these genes can operate. This is the first report of salt resistance genes recovered from metagenomes of a hypersaline environment.

  1. Dead-Time Generation in Six-Phase Frequency Inverter

    Directory of Open Access Journals (Sweden)

    Aurelijus Pitrėnas

    2016-06-01

    Full Text Available In this paper control of multi-phase induction drives is discussed. Structure of six-phase frequency inverter is examined. The article deals with dead-time generation circuits in six-phase frequency inverter for transistor control signals. Computer models of dead-time circuits is created using LTspice software package. Simulation results are compared with experimental results of the tested dead-time circuits. Parameters obtained in simulation results are close to the parameters obtained in experimental results.

  2. Adaptive control with variable dead-zone nonlinearities

    Science.gov (United States)

    Orlicki, D.; Valavani, L.; Athans, M.; Stein, G.

    1984-01-01

    It has been found that fixed error dead-zones as defined in the existing literature result in serious degradation of performance, due to the conservativeness which characterizes the determination of their width. In the present paper, variable width dead-zones are derived for the adaptive control of plants with unmodeled dynamics. The derivation makes use of information available about the unmodeled dynamics both a priori as well as during the adaptation process, so as to stabilize the adaptive loop and at the same time overcome the conservativeness and performance limitations of fixed-dead zone adaptive or fixed gain controllers.

  3. Sulfidogenesis under extremely haloalkaline conditions by Desulfonatronospira thiodismutans gen. nov., sp. nov., and Desulfonatronospira delicata sp. nov. - a novel lineage of Deltaproteobacteria from hypersaline soda lakes

    NARCIS (Netherlands)

    Sorokin, D.Y.; Tourova, T.P.; Henstra, A.M.; Stams, A.J.M.; Galinski, E.A.; Muyzer, G.

    2008-01-01

    High rates of sulfidogenesis were observed in sediments from hypersaline soda lakes. Anaerobic enrichment cultures at 2 M Na(+) and pH 10 inoculated with sediment samples from these lakes produced sulfide most actively with sulfite and thiosulfate as electron acceptors, and resulted in the isolation

  4. Desulfonatronovibrio halophilus sp. nov., a novel moderately halophilic sulfate-reducing bacterium from hypersaline chloride-sulfate lakes in Central Asia

    NARCIS (Netherlands)

    Sorokin, D.Y.; Tourova, T.P.; Abbas, B.; Suhacheva, M.V.; Muyzer, G.

    2012-01-01

    Four strains of lithotrophic sulfate-reducing bacteria (SRB) have been enriched and isolated from anoxic sediments of hypersaline chloride-sulfate lakes in the Kulunda Steppe (Altai, Russia) at 2 M NaCl and pH 7.5. According to the 16S rRNA gene sequence analysis, the isolates were closely related

  5. On the origin of endemic species in the Red Sea

    KAUST Repository

    DiBattista, Joseph

    2015-10-19

    Aim The geological and palaeo-climatic forces that produced the unique biodiversity in the Red Sea are a subject of vigorous debate. Here, we review evidence for and against the hypotheses that: (1) Red Sea fauna was extirpated during glacial cycles of the Pleistocene and (2) coral reef fauna found refuge within or just outside the Red Sea during low sea level stands when conditions were inhospitable. Location Red Sea and Western Indian Ocean. Methods We review the literature on palaeontological, geological, biological and genetic evidence that allow us to explore competing hypotheses on the origins and maintenance of shallow-water reef fauna in the Red Sea. Results Palaeontological (microfossil) evidence indicates that some areas of the central Red Sea were devoid of most plankton during low sea level stands due to hypersaline conditions caused by almost complete isolation from the Indian Ocean. However, two areas may have retained conditions adequate for survival: the Gulf of Aqaba and the southern Red Sea. In addition to isolation within the Red Sea, which separated the northern and southern faunas, a strong barrier may also operate in the region: the cold, nutrient-rich water upwelling at the boundary of the Gulf of Aden and the Arabian Sea. Biological data are either inconclusive or support these putative barriers and refugia, but no data set, that we know of rejects them. Genetic evidence suggests that many endemic lineages diverged from their Indian Ocean counterparts long before the most recent glaciations and/or are restricted to narrow areas, especially in the northern Red Sea. Main conclusions High endemism observed in the Red Sea and Gulf of Aden appears to have multiple origins. A cold, nutrient-rich water barrier separates the Gulf of Aden from the rest of the Arabian Sea, whereas a narrow strait separates the Red Sea from the Gulf of Aden, each providing potential isolating barriers. Additional barriers may arise from environmental gradients

  6. Expression of key ion transporters in the gill and esophageal-gastrointestinal tract of euryhaline Mozambique tilapia Oreochromis mossambicus acclimated to fresh water, seawater and hypersaline water.

    Directory of Open Access Journals (Sweden)

    Zhengjun Li

    Full Text Available The ability of euryhaline Mozambique tilapia to tolerate extreme environmental salinities makes it an excellent model for investigating iono-regulation. This study aimed to characterize and fill important information gap of the expression levels of key ion transporters for Na(+ and Cl(- in the gill and esophageal-gastrointestinal tract of Mozambique tilapia acclimated to freshwater (0 ppt, seawater (30 ppt and hypersaline (70 ppt environments. Among the seven genes studied, it was found that nkcc2, nkcc1a, cftr, nka-α1 and nka-α3, were more responsive to salinity challenge than nkcc1b and ncc within the investigated tissues. The ncc expression was restricted to gills of freshwater-acclimated fish while nkcc2 expression was restricted to intestinal segments irrespective of salinity challenge. Among the tissues investigated, gill and posterior intestine were found to be highly responsive to salinity changes, followed by anterior and middle intestine. Both esophagus and stomach displayed significant up-regulation of nka-α1 and nka-α3, but not nkcc isoforms and cftr, in hypersaline-acclimated fish suggesting a response to hypersalinity challenge and involvement of other forms of transporters in iono-regulation. Changes in gene expression levels were partly corroborated by immunohistochemical localization of transport proteins. Apical expression of Ncc was found in Nka-immunoreactive cells in freshwater-acclimated gills while Nkcc co-localized with Nka-immunoreactive cells expressing Cftr apically in seawater- and hypersaline-acclimated gills. In the intestine, Nkcc-stained apical brush border was found in Nka-immunoreactive cells at greater levels under hypersaline conditions. These findings provided new insights into the responsiveness of these genes and tissues under hypersalinity challenge, specifically the posterior intestine being vital for salt absorption and iono-osmoregulation in the Mozambique tilapia; its ability to survive in

  7. Biological Characterization of Microenvironments in a Hypersaline Cold Spring Mars Analog.

    Science.gov (United States)

    Sapers, Haley M; Ronholm, Jennifer; Raymond-Bouchard, Isabelle; Comrey, Raven; Osinski, Gordon R; Whyte, Lyle G

    2017-01-01

    While many habitable niches on Earth are characterized by permanently cold conditions, little is known about the spatial structure of seasonal communities and the importance of substrate-cell associations in terrestrial cyroenvironments. Here we use the 16S rRNA gene as a marker for genetic diversity to compare two visually distinct but spatially integrated surface microbial mats on Axel Heiberg Island, Canadian high arctic, proximal to a perennial saline spring. This is the first study to describe the bacterial diversity in microbial mats on Axel Heiberg Island. The hypersaline springs on Axel Heiberg represent a unique analog to putative subsurface aquifers on Mars. The Martian subsurface represents the longest-lived potentially habitable environment on Mars and a better understanding of the microbial communities on Earth that thrive in analog conditions will help direct future life detection missions. The microbial mats sampled on Axel Heiberg are only visible during the summer months in seasonal flood plains formed by melt water and run-off from the proximal spring. Targeted-amplicon sequencing revealed that not only does the bacterial composition of the two mat communities differ substantially from the sediment community of the proximal cold spring, but that the mat communities are distinct from any other microbial community in proximity to the Arctic springs studied to date. All samples are dominated by Gammaproteobacteria: Thiotichales is dominant within the spring samples while Alteromonadales comprises a significant component of the mat communities. The two mat samples differ in their Thiotichales:Alteromonadales ratio and contribution of Bacteroidetes to overall diversity. The red mats have a greater proportion of Alteromonadales and Bacteroidetes reads. The distinct bacterial composition of the mat bacterial communities suggests that the spring communities are not sourced from the surface, and that seasonal melt events create ephemerally habitable niches

  8. Metagenomic insights into the uncultured diversity and physiology of microbes in four hypersaline soda lake brines

    Directory of Open Access Journals (Sweden)

    Charlotte Dafni Vavourakis

    2016-02-01

    Full Text Available Soda lakes are salt lakes with a naturally alkaline pH due to evaporative concentration of sodium carbonates in the absence of major divalent cations. Hypersaline soda brines harbor microbial communities with a high species- and strain-level archaeal diversity and a large proportion of still uncultured poly-extremophiles compared to neutral brines of similar salinities. We present the first ‘metagenomic snapshots’ of microbial communities thriving in the brines of four shallow soda lakes from the Kulunda Steppe (Altai, Russia covering a salinity range from 170 to 400 g/L. Both amplicon sequencing of 16S rRNA fragments and direct metagenomic sequencing showed that the top-level taxa abundance was linked to the ambient salinity: Bacteroidetes, Alpha- and Gammaproteobacteria were dominant below a salinity of 250 g/L, Euryarchaeota at higher salinities. Within these taxa, amplicon sequences related to Halorubrum, Natrinema, Gracilimonas, purple non-sulfur bacteria (Rhizobiales, Rhodobacter and Rhodobaca and chemolithotrophic sulfur oxidizers (Thioalkalivibrio were highly abundant. Twenty-four draft population genomes from novel members and ecotypes within the Nanohaloarchaea, Halobacteria and Bacteroidetes were reconstructed to explore their metabolic features, environmental abundance and strategies for osmotic adaptation. The Halobacteria- and Bacteroidetes-related draft genomes belong to putative aerobic heterotrophs, likely with the capacity to ferment sugars in the absence of oxygen. Members from both taxonomic groups are likely involved in primary organic carbon degradation, since some of the reconstructed genomes encode the ability to hydrolyze recalcitrant substrates, such as cellulose and chitin. Putative sodium-pumping rhodopsins were found in both a Flavobacteriaceae- and a Chitinophagaceae-related draft genome. The predicted proteomes of both the latter and a Rhodothermaceae-related draft genome were indicative of a

  9. [Carotenogenesis of five strains of the algae Dunaliella sp. (Chlorophyceae) isolated from Venezuelan hypersaline lagoons].

    Science.gov (United States)

    Guevara, Miguel; Lodeiros, César; Gómez, Olga; Lemus, Nathalie; Núñez, Paulino; Romero, Lolymar; Vásquez, Aléikar; Rosales, Néstor

    2005-01-01

    We evaluated discontinuous cultures (Algal medium at 0.5 mM of NaNO3, and 27% NaCI) of five strains of Dunaliella sp. isolated from Venezuelan hypersaline lagoons (Araya, Coche, Peonia, Cumaraguas. and Boca Chica) and one strain from a reference collection (Dunaliella salina, LB1644). Cultures were maintained to 25+/-1 degrees C, with constant aeration, photoperiod 12:12, and two light intensities (195 and 390 microE.m(-2).s(-1)) during 30 days. Cell count was recorded on a daily basis using a Neubaüer camera. Totals of chlorophyll a and carotenoids were measured at the end of the experiment. The largest cellular densities were measured during the smallest light intensities. The strain with the largest cellular density was isolated from Boca Chica (8 xl0(6) and 2.5 xl0(6) cel.ml(-1) a 390 and 195microE.m(-2).s(-1), respectively). The increment of light intensity produced a significant reduction of growth rates in all strains. Totals of carotenoids by volume were as large as 390 microE.m(-2).s(-1). Strains LB 1644, from Coche and Araya were those that produced the largest amount of carotenoids (38.4; 32.8 and 21.0 microg.ml(-1), respectively). Differences total carotenoids by cell between treatments were significant. The largest concentration was 390 microE.m(-2).s(-1). The strains LB 1644 and Coche produced the highest values of carotenes (137.14 and 106.06 pg.cel(-1), respectively). Differences in the relation carotenoid:chlorophyll a between the strains at various light intensities was significant. Strains LB1644 presented the largest value of the relation carotenoids:chlorophyll a (20:1) at 195 microE.m(-2).s(-1). No significant differences were detected in the strain Coche (15:1). All the other strains showed relations lower than one. Our results suggest that the strains of Coche and Araya show potential to be used in the biotechnology of carotenoids production.

  10. Biological Characterization of Microenvironments in a Hypersaline Cold Spring Mars Analog

    Directory of Open Access Journals (Sweden)

    Haley M. Sapers

    2017-12-01

    Full Text Available While many habitable niches on Earth are characterized by permanently cold conditions, little is known about the spatial structure of seasonal communities and the importance of substrate-cell associations in terrestrial cyroenvironments. Here we use the 16S rRNA gene as a marker for genetic diversity to compare two visually distinct but spatially integrated surface microbial mats on Axel Heiberg Island, Canadian high arctic, proximal to a perennial saline spring. This is the first study to describe the bacterial diversity in microbial mats on Axel Heiberg Island. The hypersaline springs on Axel Heiberg represent a unique analog to putative subsurface aquifers on Mars. The Martian subsurface represents the longest-lived potentially habitable environment on Mars and a better understanding of the microbial communities on Earth that thrive in analog conditions will help direct future life detection missions. The microbial mats sampled on Axel Heiberg are only visible during the summer months in seasonal flood plains formed by melt water and run-off from the proximal spring. Targeted-amplicon sequencing revealed that not only does the bacterial composition of the two mat communities differ substantially from the sediment community of the proximal cold spring, but that the mat communities are distinct from any other microbial community in proximity to the Arctic springs studied to date. All samples are dominated by Gammaproteobacteria: Thiotichales is dominant within the spring samples while Alteromonadales comprises a significant component of the mat communities. The two mat samples differ in their Thiotichales:Alteromonadales ratio and contribution of Bacteroidetes to overall diversity. The red mats have a greater proportion of Alteromonadales and Bacteroidetes reads. The distinct bacterial composition of the mat bacterial communities suggests that the spring communities are not sourced from the surface, and that seasonal melt events create

  11. Lanthanide behavior in hypersaline evaporation ponds at Guerrero Negro, Baja California, Mexico - an environment with halophiles

    Science.gov (United States)

    Choumiline, K.; López-Cortés, A.; Grajeda-Muñoz, M.; Shumilin, E.; Sapozhnikov, D.

    2013-12-01

    Lanthanides are known, in some cases, to be sensitive to changes in water column or sediment chemistry, a fact that allows them to be used as environmental fingerprints. Nevertheless, the behavior of these elements in hypersaline environments is insufficiently understood, especially in those colonized by bacteria, archaea and eukarya halophiles. Extreme environments like the mentioned exist in the artificially-controlled ponds of the 'Exportadora de Sal' salt-producing enterprise located in Guerrero Negro (Baja California, Mexico). Sediment cores from various ponds were collected, subsampled and measured by ICP-MS and INAA. This allowed differencing the behavior of lanthanides and trace elements under a water column salinity gradient along the evaporation sequence of ponds. Sediment profiles (30 mm long), obtained in Pond 5, dominated by Ca and Mg precipitation and at the same time rich in organic matter due to bacterial mat presence, showed highs and lows of the shale-normalized patterns along different in-core depths. Two groups of elements could be distinguished with similar trends: set A (La, Ce, Pr and Nd) and set B (Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The first 'group A' had two prominent peaks at 15 mm and around 22 mm, whereas the 'group B' showed only slight increase at 15 mm and none at 22 mm. Microscopic analyses of prokaryotic cells of a stratified mat in Pond 5 (collected in 2004) showed filamentous bacteria and cyanobacteria with a cell abundance and morphotype richness maxima of prokaryotic cells in a chemocline from 3 mm to 7 mm depth which co-exists nine morphotypes of aerobic and anaerobic prokaryotes Microcoleus chthonoplastes, Leptolyngbya, Cyanothece, Geitlerinema, Spirulina, Chloroflexus, Beggiatoa, Chromatium and Thioploca. Below the 7 mm depth, oxygenic photosynthesis depletes and sulfur reducing compounds increase. The highs of the shale-normalized lanthanide contents of the 'group A' (at 15 mm depth) seem to correlate with the

  12. Oceanobacillus halophilus sp. nov., a novel moderately halophilic bacterium from a hypersaline lake.

    Science.gov (United States)

    Amoozegar, Mohammad Ali; Bagheri, Maryam; Makhdoumi, Ali; Nikou, Mahdi Moshtaghi; Fazeli, Seyed Abolhassan Shahzadeh; Schumann, Peter; Spröer, Cathrin; Sánchez-Porro, Cristina; Ventosa, Antonio

    2016-03-01

    A moderately halophilic bacterium was isolated from a brine sample of a hypersaline lake, Aran-Bidgol, in Iran. The strain, designated J8BT, was Gram-stain-positive, endospore-forming, rod-shaped, strictly aerobic, motile and produced cream colonies. Strain J8BT grew in NaCl at between 3.0-15.0 % (w/v) (optimally at 7.5 % NaCl, w/v), between pH 6.5-9.0 (optimally at pH 8.0) and between 20-45 °C (optimally at 35 °C). Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain J8BT is a member of the genus Oceanobacillus and most closely related to Oceanobacillus profundus CL-MP28T, Oceanobacillus polygoni SA9T and Oceanobacillus oncorhynchi R-2T (96.9 %, 96.3 % and 96.2 % similarities, respectively). The level of DNA-DNA relatedness between the novel isolate and O. profundus IBRC-M 10567T was 10 %. The major cellular fatty acids of the isolate were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0. The polar lipid pattern of strain J8BT consisted of phosphatidylglycerol, diphosphatidylglycerol, five phospholipids, two aminolipids and two glycoaminolipids. It contained MK-7 as the predominant menaquinone and meso-diaminopimelic acid in the cell-wall peptidoglycan. The G+C content of the genomic DNA of this strain was 39.2 mol%. Phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data suggest that this strain represents a novel species of the genus Oceanobacillus, for which the name Oceanobacillus halophilus sp. nov. is proposed. The type strain is strain J8BT ( = IBRC-M 10444T = DSM 23996T).

  13. Bacillus halosaccharovorans sp. nov., a moderately halophilic bacterium from a hypersaline lake.

    Science.gov (United States)

    Mehrshad, Maliheh; Amoozegar, Mohammad Ali; Didari, Maryam; Bagheri, Maryam; Fazeli, Seyed Abolhassan Shahzadeh; Schumann, Peter; Spröer, Cathrin; Sánchez-Porro, Cristina; Ventosa, Antonio

    2013-08-01

    A novel Gram-stain-positive, moderately halophilic bacterium, designated strain E33(T), was isolated from water of the hypersaline lake Aran-Bidgol in Iran and characterized taxonomically using a polyphasic approach. Cells of strain E33(T) were motile rods and produced ellipsoidal endospores at a central or subterminal position in swollen sporangia. Strain E33(T) was a strictly aerobic bacterium, catalase- and oxidase-positive. The strain was able to grow at NaCl concentrations of 0.5-25 % (w/v), with optimum growth occurring at 5-15 % (w/v) NaCl. The optimum temperature and pH for growth were 40 °C and pH 7.5-8.0, respectively. On the basis of 16S rRNA gene sequence analysis, strain E33(T) was shown to belong to the genus Bacillus within the phylum Firmicutes and showed the closest phylogenetic similarity with the species Bacillus niabensis 4T19(T) (99.2 %), Bacillus herbersteinensis D-1-5a(T) (97.3 %) and Bacillus litoralis SW-211(T) (97.2 %). The DNA G+C content of the type strain of the novel species was 42.6 mol%. The major cellular fatty acids of strain E33(T) were anteiso-C15 : 0 and iso-C15 : 0, and the polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, two unknown glycolipids, an unknown lipid and an unknown phospholipid. The isoprenoid quinones were MK-7 (97 %), MK-6 (2 %) and MK-8 (0.5 %). The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. All these features confirm the placement of isolate E33(T) within the genus Bacillus. DNA-DNA hybridization experiments revealed low levels of relatedness between strain E33(T) and Bacillus niabensis IBRC-M 10590(T) (22 %), Bacillus herbersteinensis CCM 7228(T) (38 %) and Bacillus litoralis DSM 16303(T) (19 %). On the basis of polyphasic evidence from this study, a novel species of the genus Bacillus, Bacillus halosaccharovorans sp. nov. is proposed, with strain E33(T) (= IBRC-M 10095(T) = DSM 25387(T)) as the type strain.

  14. Bacillus salsus sp. nov., a halophilic bacterium from a hypersaline lake.

    Science.gov (United States)

    Amoozegar, Mohammad Ali; Didari, Maryam; Bagheri, Maryam; Fazeli, Seyed Abolhassan Shahzadeh; Schumann, Peter; Spröer, Cathrin; Sánchez-Porro, Cristina; Ventosa, Antonio

    2013-09-01

    A Gram-staining-positive, endospore-forming, rod-shaped, strictly aerobic, slightly halophilic bacterium, designated strain A24(T), was isolated from the hypersaline lake Aran-Bidgol in Iran. Cells of strain A24(T) were motile rods and produced oval endospores at a terminal position in swollen sporangia. Strain A24(T) was catalase and oxidase positive. Growth occurred with between 0.5 and 7.5% (w/v) NaCl and the isolate grew optimally at 3% (v/w) NaCl. The optimum temperature and pH for growth were 35 °C and pH 8.0, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain A24(T) belonged to the genus Bacillus within the phylum Firmicutes and showed the closest phylogenetic similarity with the species Bacillus alkalitelluris BA288(T) (97.2%), Bacillus herbersteinensis D-1,5a(T) (96.0%) and Bacillus litoralis SW-211(T) (95.6%). The G+C content of the genomic DNA of this strain was 35.9 mol%. The polar lipid pattern of strain A24(T) consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and two unknown phospholipids. The major cellular fatty acids of strain A24(T) were anteiso-C(15:0) and iso-C(15:0). The respiratory quinones were MK-7 (94%) and MK-6 (4%). The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. All these features confirm the placement of isolate A24(T) within the genus Bacillus. DNA-DNA hybridization experiments revealed a relatedness of 8% between strain A24(T) and Bacillus alkalitelluris IBRC-M 10596(T), supporting its placement as a novel species. Phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data suggest that this strain represents a novel species of the genus Bacillus, for which the name Bacillus salsus sp. nov. is proposed. The type strain is strain A24(T) ( = IBRC-M 10078 (T) = KCTC 13816(T)).

  15. Bacillus persicus sp. nov., a halophilic bacterium from a hypersaline lake.

    Science.gov (United States)

    Didari, Maryam; Amoozegar, Mohammad Ali; Bagheri, Maryam; Mehrshad, Maliheh; Schumann, Peter; Spröer, Cathrin; Sánchez-Porro, Cristina; Ventosa, Antonio

    2013-04-01

    A novel gram-positive, slightly halophilic bacterium, designated strain B48(T), was isolated from soil around the hypersaline lake Aran-Bidgol in Iran and characterized taxonomically using a polyphasic approach. Cells of strain B48(T) were non-motile rods and produced ellipsoidal endospores at a central or subterminal position in swollen sporangia. Strain B48(T) was a strictly aerobic bacterium, catalase- and oxidase-positive. The strain was able to grow at NaCl concentrations of 0.5-10.0 % (w/v), with optimum growth occurring at 2.5 % (w/v) NaCl. The optimum temperature and pH for growth were 35 °C and pH 7.5-8.0, respectively. On the basis of 16S rRNA gene sequence analysis, strain B48(T) was shown to belong to the genus Bacillus within the phylum Firmicutes and showed the closest phylogenetic similarity to the species Bacillus foraminis CV53(T) (97.4 %) and Bacillus purgationiresistens DS22(T) (96.9 %). The DNA G+C content of this new isolate was 40.1 mol%. The major cellular fatty acids of strain B48(T) were iso-C15 : 0 and anteiso-C15 : 0, and its polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an aminophospholipid and two unknown phospholipids. The only quinone present was menaquinone 7 (MK-7). The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. All these features confirm the placement of isolate B48(T) within the genus Bacillus. DNA-DNA hybridization experiments revealed a low level of relatedness between strain B48(T) and Bacillus foraminis IBRC-M 10625(T) (8.1 %). On the basis of polyphasic evidence from this study, a new species of the genus Bacillus, Bacillus persicus sp. nov., is proposed, with strain B48(T) ( = IBRC-M 10115(T) = DSM 25386(T) = CECT 8001(T)) as the type strain.

  16. Saliterribacillus persicus gen. nov., sp. nov., a moderately halophilic bacterium isolated from a hypersaline lake.

    Science.gov (United States)

    Amoozegar, Mohammad Ali; Bagheri, Maryam; Didari, Maryam; Shahzedeh Fazeli, Seyed Abolhassan; Schumann, Peter; Sánchez-Porro, Cristina; Ventosa, Antonio

    2013-01-01

    A novel Gram-positive, moderately halophilic bacterium, designated strain X4B(T), was isolated from soil around the hypersaline lake Aran-Bidgol in Iran and characterized taxonomically using a polyphasic approach. Cells of strain X4B(T) were motile rods and formed ellipsoidal endospores at a terminal or subterminal position in swollen sporangia. Strain X4B(T) was a strictly aerobic bacterium, catalase- and oxidase-positive. The strain was able to grow at NaCl concentrations of 0.5-22.5 % (w/v), with optimum growth occurring at 7.5 % (w/v) NaCl. The optimum temperature and pH for growth were 35 °C and pH 7.0. Analysis of 16S rRNA gene sequence revealed that strain X4B(T) is a member of the family Bacillaceae, constituting a novel phyletic lineage within this family. Highest sequence similarities were obtained with the 16S rRNA gene sequences of the type strains of Sediminibacillus albus (96.0 %), Paraliobacillus ryukyuensis (95.9 %), Paraliobacillus quinghaiensis (95.8 %) and Sediminibacillus halophilus (95.7 %), respectively. The DNA G+C content of this novel isolate was 35.2 mol%. The major cellular fatty acids of strain X4B(T) were anteiso-C(15 : 0) and anteiso-C(17 : 0) and its polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, two aminolipids, an aminophospholipid and an unknown phospholipid. The isoprenoid quinones were MK-7 (89 %) and MK-6 (11 %). The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. On the basis of 16S rRNA gene sequence analysis in combination with chemotaxonomic and phenotypic data, strain X4B(T) represents a novel species in a new genus in the family Bacillaceae, order Bacillales for which the name Saliterribacillus persicus gen. nov., sp. nov. is proposed. The type strain of the type species (Saliterribacillus persicus) is X4B(T) ( = IBRC-M 10629(T) = KCTC 13827(T)).

  17. Addicts Try to Avoid Deadly Fentanyl, but Many Tragically Fail

    Science.gov (United States)

    ... fullstory_166663.html Addicts Try to Avoid Deadly Fentanyl, But Many Tragically Fail Potent synthetic opioid now ... may be caused by the potent synthetic opioid fentanyl. But most opioid addicts are not actively seeking ...

  18. Dead time effects in laser Doppler anemometry measurements

    DEFF Research Database (Denmark)

    Velte, Clara Marika; Buchhave, Preben; George, William K.

    2014-01-01

    frequency range, starting around the cutoff frequency due to the finite size of the MV. Using computer-generated data mimicking the LDA data, these effects have previously been shown to appear due to the effect of dead time, i.e., the finite time during which the system is not able to acquire new...... measurements. These dead times can be traced back to the fact that the burst-mode LDA cannot measure more than one signal burst at a time. Since the dead time is approximately equal to the residence time for a particle traversing a measurement volume, we are dealing with widely varying dead times, which......, however, are assumed to be measured for each data point. In addition, the detector and processor used in the current study introduce a certain amount of fixed processing and data transfer times, which further contribute to the distortion of the computed spectrum. However, we show an excellent agreement...

  19. Dead zone area at the downstream flow of barrages

    Directory of Open Access Journals (Sweden)

    Mohamed F. Sauida

    2016-12-01

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

  20. The dead and gone: Preparations and final repose

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The relations between the living and the dead are sanctioned by specific departure ceremonies and a series of maintenance operations that vary in their elaboration...

  1. Dead Crow Density and West Nile Virus Monitoring, New York

    Science.gov (United States)

    Schmit, Kate; Hagiwara, Yoichiro; Anand, Madhu; Backenson, P. Bryon; Gotham, Ivan; Kramer, Laura

    2005-01-01

    New York State used the health commerce system to monitor the number of West Nile virus (WNV) human disease cases and the density of dead crows. In each year from 2001 to 2003 and for the 3 years combined, persons living in New York counties (excluding New York City) with elevated weekly dead crow densities (above a threshold value of 0.1 dead crows per square mile) had higher risk (2.0–8.6 times) for disease caused by WNV within the next 2 weeks than residents of counties reporting fewer dead crows per square mile. This type of index can offer a real-time, relatively inexpensive window into viral activity in time for prevention and control. Changes in reporting, bird populations, and immunity may require that thresholds other than 0.1 be used in later years or in other areas. PMID:16229764

  2. [The role of dead bacteria in streptococcus sanguis biofilm reformation].

    Science.gov (United States)

    Ma, Rui; Zhu, Min; Liu, Zheng

    2002-03-01

    To investigate the role of dead bacteria in Streptococcus sanguis biofilm reformation. Vital fluorescent staining technique and Confocal laser Scanning Microscopy (CLSM) were combined to observe Streptococcus sanguis biofilm on the saliva-coated glass (SCG) in an artificial mouth model, the thickness and bacterial density were compared between biofilm reformed on saliva covered slide with dead cells (test group) and biofilm reformed on saliva coated slide without dead cells (control group) at different times. At 30 min, the bacterial density rather than biofilm thickness of test group was significantly higher than that of control group (P<0.05), whereas at 60 min, 120min, 240min, the biofilms were significantly thicker in test group than that (P<0.05). The dead cells may help biofilm reformation during the formation of biofilm.

  3. Can volatile organic compounds be markers of sea salt?

    Science.gov (United States)

    Silva, Isabel; Coimbra, Manuel A; Barros, António S; Marriott, Philip J; Rocha, Sílvia M

    2015-02-15

    Sea salt is a handmade food product that is obtained by evaporation of seawater in saltpans. During the crystallisation process, organic compounds from surroundings can be incorporated into sea salt crystals. The aim of this study is to search for potential volatile markers of sea salt. Thus, sea salts from seven north-east Atlantic Ocean locations (France, Portugal, Continental Spain, Canary Islands, and Cape Verde) were analysed by headspace solid-phase microextraction combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry. A total of 165 compounds were detected, ranging from 32 to 71 compounds per salt. The volatile composition revealed the variability and individuality of each salt, and a set of ten compounds were detected in all samples. From these, seven are carotenoid-derived compounds that can be associated with the typical natural surroundings of ocean hypersaline environment. These ten compounds are proposed as potential volatile markers of sea salt. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Forensic-odontological age determination in living and dead persons

    OpenAIRE

    Olze, Andreas

    2010-01-01

    Forensic-odontological determination of the age-at-death of dead, unknown persons is a traditional element of forensic odonto-stomatology. Besides the comparison of documents on ante- and post-mortem findings, an age estimate that is as accurate as possible is an important tool for identifying unknown dead persons, because it allows limiting the group of persons in question. Age estimation is, in principle, possible by measuring the degree of root dentin transparency; it yields good result...

  5. The DEAD-box helicase eIF4A

    Science.gov (United States)

    Andreou, Alexandra Z.; Klostermeier, Dagmar

    2013-01-01

    DEAD-box helicases catalyze the ATP-dependent unwinding of RNA duplexes. They share a helicase core formed by two RecA-like domains that carries a set of conserved motifs contributing to ATP binding and hydrolysis, RNA binding and duplex unwinding. The translation initiation factor eIF4A is the founding member of the DEAD-box protein family, and one of the few examples of DEAD-box proteins that consist of a helicase core only. It is an RNA-stimulated ATPase and a non-processive helicase that unwinds short RNA duplexes. In the catalytic cycle, a series of conformational changes couples the nucleotide cycle to RNA unwinding. eIF4A has been considered a paradigm for DEAD-box proteins, and studies of its function have revealed the governing principles underlying the DEAD-box helicase mechanism. However, as an isolated helicase core, eIF4A is rather the exception, not the rule. Most helicase modules in other DEAD-box proteins are modified, some by insertions into the RecA-like domains, and the majority by N- and C-terminal appendages. While the basic catalytic function resides within the helicase core, its modulation by insertions, additional domains or a network of interaction partners generates the diversity of DEAD-box protein functions in the cell. This review summarizes the current knowledge on eIF4A and its regulation, and discusses to what extent eIF4A serves as a model DEAD-box protein. PMID:22995829

  6. Dead Zones and the Origin of Planetary Masses

    OpenAIRE

    Matsumura, Soko; Pudritz, Ralph E.

    2004-01-01

    Protoplanets accrete material from their natal protostellar disks until they are sufficiently massive to open a gap in the face of the disk's viscosity that arises from the magneto-rotational instability (MRI). By computing the ionization structure within observationally well-constrained disk models, we demonstrate that poorly ionized, low viscosity "dead zones" stretch out to 12 AU within typical disks. We find that planets of terrestrial mass robustly form within the dead zones while massiv...

  7. The dead donor rule: can it withstand critical scrutiny?

    Science.gov (United States)

    Miller, Franklin G; Truog, Robert D; Brock, Dan W

    2010-06-01

    Transplantation of vital organs has been premised ethically and legally on "the dead donor rule" (DDR)-the requirement that donors are determined to be dead before these organs are procured. Nevertheless, scholars have argued cogently that donors of vital organs, including those diagnosed as "brain dead" and those declared dead according to cardiopulmonary criteria, are not in fact dead at the time that vital organs are being procured. In this article, we challenge the normative rationale for the DDR by rejecting the underlying premise that it is necessarily wrong for physicians to cause the death of patients and the claim that abandoning this rule would exploit vulnerable patients. We contend that it is ethical to procure vital organs from living patients sustained on life support prior to treatment withdrawal, provided that there is valid consent for both withdrawing treatment and organ donation. However, the conservatism of medical ethics and practical concerns make it doubtful that the DDR will be abandoned in the near future. This leaves the current practice of organ transplantation based on the "moral fiction" that donors are dead when vital organs are procured.

  8. Metagenomic insights into important microbes from the Dead Zone

    Science.gov (United States)

    Thrash, C.; Baker, B.; Seitz, K.; Temperton, B.; Gillies, L.; Rabalais, N. N.; Mason, O. U.

    2015-12-01

    Coastal regions of eutrophication-driven oxygen depletion are widespread and increasing in number. Also known as dead zones, these regions take their name from the deleterious effects of hypoxia (dissolved oxygen less than 2 mg/L) on shrimp, demersal fish, and other animal life. Dead zones result from nutrient enrichment of primary production, concomitant consumption by chemoorganotrophic aerobic microorganisms, and strong stratification that prevents ventilation of bottom water. One of the largest dead zones in the world occurs seasonally in the northern Gulf of Mexico (nGOM), where hypoxia can reach up to 22,000 square kilometers. While this dead zone shares many features with more well-known marine oxygen minimum zones, it is nevertheless understudied with regards to the microbial assemblages involved in biogeochemical cycling. We performed metagenomic and metatranscriptomic sequencing on six samples from the 2013 nGOM dead zone from both hypoxic and oxic bottom waters. Assembly and binning led to the recovery of over fifty partial to nearly complete metagenomes from key microbial taxa previously determined to be numerically abundant from 16S rRNA data, such as Thaumarcheaota, Marine Group II Euryarchaeota, SAR406, SAR324, Synechococcus spp., and Planctomycetes. These results provide information about the roles of these taxa in the nGOM dead zone, and opportunities for comparing this region of low oxygen to others around the globe.

  9. The dead donor rule, voluntary active euthanasia, and capital punishment.

    Science.gov (United States)

    Coons, Christian; Levin, Noah

    2011-06-01

    We argue that the dead donor rule, which states that multiple vital organs should only be taken from dead patients, is justified neither in principle nor in practice. We use a thought experiment and a guiding assumption in the literature about the justification of moral principles to undermine the theoretical justification for the rule. We then offer two real world analogues to this thought experiment, voluntary active euthanasia and capital punishment, and argue that the moral permissibility of terminating any patient through the removal of vital organs cannot turn on whether or not the practice violates the dead donor rule. Next, we consider practical justifications for the dead donor rule. Specifically, we consider whether there are compelling reasons to promulgate the rule even though its corresponding moral principle is not theoretically justified. We argue that there are no such reasons. In fact, we argue that promulgating the rule may actually decrease public trust in organ procurement procedures and medical institutions generally - even in states that do not permit capital punishment or voluntary active euthanasia. Finally, we examine our case against the dead donor rule in the light of common arguments for it. We find that these arguments are often misplaced - they do not support the dead donor rule. Instead, they support the quite different rule that patients should not be killed for their vital organs.

  10. Dead time corrections for inbeam γ-spectroscopy measurements

    Science.gov (United States)

    Boromiza, M.; Borcea, C.; Negret, A.; Olacel, A.; Suliman, G.

    2017-08-01

    Relatively high counting rates were registered in a proton inelastic scattering experiment on 16O and 28Si using HPGe detectors which was performed at the Tandem facility of IFIN-HH, Bucharest. In consequence, dead time corrections were needed in order to determine the absolute γ-production cross sections. Considering that the real counting rate follows a Poisson distribution, the dead time correction procedure is reformulated in statistical terms. The arriving time interval between the incoming events (Δt) obeys an exponential distribution with a single parameter - the average of the associated Poisson distribution. We use this mathematical connection to calculate and implement the dead time corrections for the counting rates of the mentioned experiment. Also, exploiting an idea introduced by Pommé et al., we describe a consistent method for calculating the dead time correction which completely eludes the complicated problem of measuring the dead time of a given detection system. Several comparisons are made between the corrections implemented through this method and by using standard (phenomenological) dead time models and we show how these results were used for correcting our experimental cross sections.

  11. Memorial service: A means of communication with the dead

    Directory of Open Access Journals (Sweden)

    Ivanović-Barišić Milina M.

    2005-01-01

    Full Text Available A specific relationship toward the dead characterizes the traditional Serbian culture; this cult exists even today, in somewhat changed form. A death is always followed by the appropriate, traditional, ritual obligations that served to regulate behavior of a family, or even wider community members that has lost one of its members. The relationship with the dead does not cease after the funeral, but it continues to be maintained during general holidays dedicated to the dead-memorial service. These are the days dedicated to all dead, and when offerings were made especially for the deceased. The memorial services take place in particular days of the year: most often on Saturdays, on Saturdays before another holiday, the Spirits, and on Saturdays before the holiday Mitrovdan; memorial services are also connected with some other holidays during the year. In addition to the general memorial service dedicated to all dead, there are so-called special memorial services, which take place only in special occasions (on holidays like Petrovdan, Saint Ilija, Velika Gospojina, Trojice and more. Many different rituals performed during memorial services, as well as ritual objects used should provide the deceased with a safe residence in their new environment. The most important rituals that enabled the communication with the dead include: preparing and sharing food and drinks, visits to a cemetery, lighting candles, incense of graves, vine spilling, decoration with flowers and basilica. The most important ritual objects are: graves, food, drinks, candles, incense, vine, flowers and basilica.

  12. Living with the Dead or Communicating with the dead: media practices of continuing bonds among bereaved parents

    DEFF Research Database (Denmark)

    Sandvik, Kjetil; Christensen, Dorthe Refslund

    for this paper analyzing bereaved parent’ communicational practices in order to create continuing bonds (Klass et.al. 1996) to their dead children. The use of media and materialities ascribed with media qualities allows us to “deal with and come to terms with death without being dead ourselves” (Christensen...... in the shape of everyday parental activities such as playing with the child, reading bedtime stories, celebrating birthdays or just bearing the dead child in mind, the purpose of which are to keep the dead child as a present part of the parents’ and family’s continuing life. We argue that these practices...... are best understood as parents’ everyday practices relating to a child we have rather than to a child we had or a child we did not get. The child’s continuing existence and presence is inscribed in everyday life through uses of digital media, physical objects working as media – even the parents own bodies...

  13. Ecological quality assessment in the Eastern Mediterranean combining live and dead molluscan assemblages.

    Science.gov (United States)

    Leshno, Yael; Benjamini, Chaim; Edelman-Furstenberg, Yael

    2016-03-15

    The EU directive to quantify ecological quality by deviation from pre-impacted conditions often fails to be implemented because past information is usually incomplete or missing. Molluscan death assemblages, representing long-term accumulation of shells on the sea floor, average out short-term variability and can serve as a baseline for quality assessment. AMBI, Bentix and Shannon-Wiener indices were calculated for live and dead assemblages from polluted and control stations on the highly oligotrophic Levantine shallow shelf of Israel. Bentix successfully tracked deterioration over time, from moderate EcoQS in the dead to poor in the live assemblage. Additional modification of the ecological classification of species by scoring the naturally abundant Corbula gibba as pollution-sensitive improved the utility of the Bentix index in monitoring in this part of the Mediterranean. This adjustment of Bentix, and use of death assemblages for an ecological baseline, should therefore be incorporated in monitoring for compliance with EU directives. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Diatoms dominate the eukaryotic metatranscriptome during spring in coastal 'dead zone' sediments.

    Science.gov (United States)

    Broman, Elias; Sachpazidou, Varvara; Dopson, Mark; Hylander, Samuel

    2017-10-11

    An important characteristic of marine sediments is the oxygen concentration that affects many central metabolic processes. There has been a widespread increase in hypoxia in coastal systems (referred to as 'dead zones') mainly caused by eutrophication. Hence, it is central to understand the metabolism and ecology of eukaryotic life in sediments during changing oxygen conditions. Therefore, we sampled coastal 'dead zone' Baltic Sea sediment during autumn and spring, and analysed the eukaryotic metatranscriptome from field samples and after incubation in the dark under oxic or anoxic conditions. Bacillariophyta (diatoms) dominated the eukaryotic metatranscriptome in spring and were also abundant during autumn. A large fraction of the diatom RNA reads was associated with the photosystems suggesting a constitutive expression in darkness. Microscope observation showed intact diatom cells and these would, if hatched, represent a significant part of the pelagic phytoplankton biomass. Oxygenation did not significantly change the relative proportion of diatoms nor resulted in any major shifts in metabolic 'signatures'. By contrast, diatoms rapidly responded when exposed to light suggesting that light is limiting diatom development in hypoxic sediments. Hence, it is suggested that diatoms in hypoxic sediments are on 'standby' to exploit the environment if they reach suitable habitats. © 2017 The Author(s).

  15. Options for reducing HIV transmission related to the dead space in needles and syringes.

    Science.gov (United States)

    Zule, William A; Pande, Poonam G; Otiashvili, David; Bobashev, Georgiy V; Friedman, Samuel R; Gyarmathy, V Anna; Des Jarlais, Don C

    2018-01-15

    When shared by people who inject drugs, needles and syringes with different dead space may affect the probability of HIV and hepatitis C virus (HCV) transmission differently. We measured dead space in 56 needle and syringe combinations obtained from needle and syringe programs across 17 countries in Europe and Asia. We also calculated the amounts of blood and HIV that would remain in different combinations following injection and rinsing. Syringe barrel capacities ranged from 0.5 to 20 mL. Needles ranged in length from 8 to 38 mm. The average dead space was 3 μL in low dead space syringes with permanently attached needles, 13 μL in high dead space syringes with low dead space needles, 45 μL in low dead space syringes with high dead space needles, and 99 μL in high dead space syringes with high dead space needles. Among low dead space designs, calculated volumes of blood and HIV viral burden were lowest for low dead space syringes with permanently attached needles and highest for low dead space syringes with high dead space needles. The dead space in different low dead space needle and syringe combinations varied substantially. To reduce HIV transmission related to syringe sharing, needle and syringe programs need to combine this knowledge with the needs of their clients.

  16. Complete genome sequence of Desulfurivibrio alkaliphilus strain AHT2(T), a haloalkaliphilic sulfidogen from Egyptian hypersaline alkaline lakes.

    Science.gov (United States)

    Melton, Emily Denise; Sorokin, Dimitry Y; Overmars, Lex; Chertkov, Olga; Clum, Alicia; Pillay, Manoj; Ivanova, Natalia; Shapiro, Nicole; Kyrpides, Nikos C; Woyke, Tanja; Lapidus, Alla L; Muyzer, Gerard

    2016-01-01

    Desulfurivibrio alkaliphilus strain AHT2(T) is a strictly anaerobic sulfidogenic haloalkaliphile isolated from a composite sediment sample of eight hypersaline alkaline lakes in the Wadi al Natrun valley in the Egyptian Libyan Desert. D. alkaliphilus AHT2(T) is Gram-negative and belongs to the family Desulfobulbaceae within the Deltaproteobacteria. Here we report its genome sequence, which contains a 3.10 Mbp chromosome. D. alkaliphilus AHT2(T) is adapted to survive under highly alkaline and moderately saline conditions and therefore, is relevant to the biotechnology industry and life under extreme conditions. For these reasons, D. alkaliphilus AHT2(T) was sequenced by the DOE Joint Genome Institute as part of the Community Science Program.

  17. Spatially-resolved carbon flow through a hypersaline phototrophic microbial mat

    Science.gov (United States)

    Moran, J.; Lindemann, S. R.; Cory, A. B.; Courtney, S.; Cole, J. K.; Fredrickson, J.

    2013-12-01

    Hot Lake is a hypersaline, meromictic lake located in an endorheic basin in north-central Washington. Low annual rainfall and high evaporation rates contribute to the lake's high salinity. The predominant dissolved salt is magnesium sulfate, of which monimolimnion waters may seasonally exceed 2 M concentrations. Induced by its high salinity and meromictic nature, Hot Lake displays an inverse thermal gradient with deep horizons seasonally exceeding 50 °C. Despite extreme conditions, dense benthic microbial mats composed of cyanobacteria, anoxygenic photoheterotrophs, and bacterial heterotroph populations develop in the lake. These mats can exceed 1 cm in thickness and display vertical stratification in color due to bacterial pigmentation. Typical mat stratification includes an orange surface layer underlain by green and purple layers at increasing depth. Carbonates, including aragonite and magnesite, are observed within the mat and their formation is likely induced or influenced by microbial metabolic activities and associated pH excursions. We are exploring the role Hot Lake's microbial mats play in carbon cycling. Cyanobacteria are the dominant CO2-fixing organisms in the mat and we seek to understand the spatial and metabolic controls on how the carbon initially fixed by mat cyanobacteria is transferred to associated heterotrophic populations spread throughout the mat strata. Secondly, we seek to understand the overall net carbon balance of the mat through a growing season. We are using a stable isotope probing approach for assessing carbon uptake and migration through representative mat samples. We performed a series of ex situ incubations of freshly harvested mat samples in lake water amended with 13C-labeled bicarbonate or substrates commonly consumed by heterotrophs (including acetate and glucose) and using multiple stable isotope techniques to track label uptake, residence time, remineralization, and location within the mat. In addition to bulk isotope

  18. Community Structure and Activity of a Highly Dynamic and Nutrient-Limited Hypersaline Microbial Mat in Um Alhool Sabkha, Qatar

    KAUST Repository

    Al-Thani, Roda

    2014-03-21

    The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1–L4) in the photosynthetic mats. Chlorophyll a (Chl a) concentration and distribution (measured by HPLC and hyperspectral imaging, respectively), the phycocyanin distribution (scanned with hyperspectral imaging), oxygenic photosynthesis (determined by microsensor), and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing) decreased with depth in the euphotic layer (L1). Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%–42% of the identified bacteria). Anoxygenic photosynthetic bacteria (dominated by Chloroflexus) were most abundant in the third red layer of the mat (L3), evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4) was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35S tracer). Members of Halobacteria were the dominant Archaea in all layers of the mat (92%–97%), whereas Nematodes were the main Eukaryotes (up to 87%). Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods.

  19. Diversity and function of Chloroflexus-like bacteria in a hypersaline microbial mat: phylogenetic characterization and impact on aerobic respiration.

    Science.gov (United States)

    Bachar, Ami; Omoregie, Enoma; de Wit, Rutger; Jonkers, Henk M

    2007-06-01

    We studied the diversity of Chloroflexus-like bacteria (CLB) in a hypersaline phototrophic microbial mat and assayed their near-infrared (NIR) light-dependent oxygen respiration rates. PCR with primers that were reported to specifically target the 16S rRNA gene from members of the phylum Chloroflexi resulted in the recovery of 49 sequences and 16 phylotypes (sequences of the same phylotype share more than 96% similarity), and 10 of the sequences (four phylotypes) appeared to be related to filamentous anoxygenic phototrophic members of the family Chloroflexaceae. Photopigment analysis revealed the presence of bacteriochlorophyll c (BChlc), BChld, and gamma-carotene, pigments known to be produced by phototrophic CLB. Oxygen microsensor measurements for intact mats revealed a NIR (710 to 770 nm) light-dependent decrease in aerobic respiration, a phenomenon that we also observed in an axenic culture of Chloroflexus aurantiacus. The metabolic ability of phototrophic CLB to switch from anoxygenic photosynthesis under NIR illumination to aerobic respiration under non-NIR illumination was further used to estimate the contribution of these organisms to mat community respiration. Steady-state oxygen profiles under dark conditions and in the presence of visible (VIS) light (400 to 700 nm), NIR light (710 to 770 nm), and VIS light plus NIR light were compared. NIR light illumination led to a substantial increase in the oxygen concentration in the mat. The observed impact on oxygen dynamics shows that CLB play a significant role in the cycling of carbon in this hypersaline microbial mat ecosystem. This study further demonstrates that the method applied, a combination of microsensor techniques and VIS and NIR illumination, allows rapid establishment of the presence and significance of CLB in environmental samples.

  20. Community structure and activity of a highly dynamic and nutrient-limited hypersaline microbial mat in Um Alhool Sabkha, Qatar.

    Directory of Open Access Journals (Sweden)

    Roda Al-Thani

    Full Text Available The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1-L4 in the photosynthetic mats. Chlorophyll a (Chl a concentration and distribution (measured by HPLC and hyperspectral imaging, respectively, the phycocyanin distribution (scanned with hyperspectral imaging, oxygenic photosynthesis (determined by microsensor, and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing decreased with depth in the euphotic layer (L1. Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%-42% of the identified bacteria. Anoxygenic photosynthetic bacteria (dominated by Chloroflexus were most abundant in the third red layer of the mat (L3, evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4 was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35S tracer. Members of Halobacteria were the dominant Archaea in all layers of the mat (92%-97%, whereas Nematodes were the main Eukaryotes (up to 87%. Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods.

  1. Diversity and Function of Chloroflexus-Like Bacteria in a Hypersaline Microbial Mat: Phylogenetic Characterization and Impact on Aerobic Respiration▿

    Science.gov (United States)

    Bachar, Ami; Omoregie, Enoma; de Wit, Rutger; Jonkers, Henk M.

    2007-01-01

    We studied the diversity of Chloroflexus-like bacteria (CLB) in a hypersaline phototrophic microbial mat and assayed their near-infrared (NIR) light-dependent oxygen respiration rates. PCR with primers that were reported to specifically target the 16S rRNA gene from members of the phylum Chloroflexi resulted in the recovery of 49 sequences and 16 phylotypes (sequences of the same phylotype share more than 96% similarity), and 10 of the sequences (four phylotypes) appeared to be related to filamentous anoxygenic phototrophic members of the family Chloroflexaceae. Photopigment analysis revealed the presence of bacteriochlorophyll c (BChlc), BChld, and γ-carotene, pigments known to be produced by phototrophic CLB. Oxygen microsensor measurements for intact mats revealed a NIR (710 to 770 nm) light-dependent decrease in aerobic respiration, a phenomenon that we also observed in an axenic culture of Chloroflexus aurantiacus. The metabolic ability of phototrophic CLB to switch from anoxygenic photosynthesis under NIR illumination to aerobic respiration under non-NIR illumination was further used to estimate the contribution of these organisms to mat community respiration. Steady-state oxygen profiles under dark conditions and in the presence of visible (VIS) light (400 to 700 nm), NIR light (710 to 770 nm), and VIS light plus NIR light were compared. NIR light illumination led to a substantial increase in the oxygen concentration in the mat. The observed impact on oxygen dynamics shows that CLB play a significant role in the cycling of carbon in this hypersaline microbial mat ecosystem. This study further demonstrates that the method applied, a combination of microsensor techniques and VIS and NIR illumination, allows rapid establishment of the presence and significance of CLB in environmental samples. PMID:17449697

  2. Community structure and activity of a highly dynamic and nutrient-limited hypersaline microbial mat in Um Alhool Sabkha, Qatar.

    Science.gov (United States)

    Al-Thani, Roda; Al-Najjar, Mohammad A A; Al-Raei, Abdul Munem; Ferdelman, Tim; Thang, Nguyen M; Al Shaikh, Ismail; Al-Ansi, Mehsin; de Beer, Dirk

    2014-01-01

    The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1-L4) in the photosynthetic mats. Chlorophyll a (Chl a) concentration and distribution (measured by HPLC and hyperspectral imaging, respectively), the phycocyanin distribution (scanned with hyperspectral imaging), oxygenic photosynthesis (determined by microsensor), and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing) decreased with depth in the euphotic layer (L1). Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%-42% of the identified bacteria). Anoxygenic photosynthetic bacteria (dominated by Chloroflexus) were most abundant in the third red layer of the mat (L3), evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4) was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35S tracer). Members of Halobacteria were the dominant Archaea in all layers of the mat (92%-97%), whereas Nematodes were the main Eukaryotes (up to 87%). Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods.

  3. Hypersalinity reduces the risk of cyanide toxicosis to insectivorous bats interacting with wastewater impoundments at gold mines.

    Science.gov (United States)

    Griffiths, Stephen R; Donato, David B; Lumsden, Linda F; Coulson, Graeme

    2014-01-01

    Wildlife and livestock that ingest bioavailable cyanide compounds in gold mining tailings dams are known to experience cyanide toxicosis. Elevated levels of salinity in open impoundments have been shown to prevent wildlife cyanide toxicosis by reducing drinking and foraging. This finding appears to be consistent for diurnal wildlife interacting with open impoundments, however the risks to nocturnal wildlife of cyanide exposure are unknown. We investigated the activity of insectivorous bats in the airspace above both fresh (potable to wildlife) and saline water bodies at two gold mines in the goldfields of Western Australian. During this study, cyanide-bearing solutions stored in open impoundments at both mine sites were hypersaline (range=57,000-295,000 mg/L total dissolved solids (TDS)), well above known physiological tolerance of any terrestrial vertebrate. Bats used the airspace above each water body monitored, but were more active at fresh than saline water bodies. In addition, considerably more terminal echolocation buzz calls were recorded in the airspace above fresh than saline water bodies at both mine sites. However, it was not possible to determine whether these buzz calls corresponded to foraging or drinking bouts. No drinking bouts were observed in 33 h of thermal video footage recorded at one hypersaline tailings dam, suggesting that this water is not used for drinking. There is no information on salinity tolerances of bats, but it could be assumed that bats would not tolerate salinity in drinking water at concentrations greater than those documented as toxic for saline-adapted terrestrial wildlife. Therefore, when managing wastewater impoundments at gold mines to avoid wildlife mortalities, adopting a precautionary principle, bats are unlikely to drink solutions at salinity levels ≥50,000 mg/L TDS. © 2013 Published by Elsevier Inc.

  4. Focused Transhepatic Electroporation Mediated by Hypersaline Infusion through the Portal Vein in Rat Model. Preliminary Results on Differential Conductivity.

    Science.gov (United States)

    Pañella, Clara; Castellví, Quim; Moll, Xavier; Quesada, Rita; Villanueva, Alberto; Iglesias, Mar; Naranjo, Dolores; Sánchez-Velázquez, Patricia; Andaluz, Anna; Grande, Luís; Ivorra, Antoni; Burdío, Fernando

    2017-12-01

    Spread hepatic tumours are not suitable for treatment either by surgery or conventional ablation methods. The aim of this study was to evaluate feasibility and safety of selectively increasing the healthy hepatic conductivity by the hypersaline infusion (HI) through the portal vein. We hypothesize this will allow simultaneous safe treatment of all nodules by irreversible electroporation (IRE) when applied in a transhepatic fashion. Sprague Dawley (Group A, n = 10) and Athymic rats with implanted hepatic tumour (Group B, n = 8) were employed. HI was performed (NaCl 20%, 3.8 mL/Kg) by trans-splenic puncture. Deionized serum (40 mL/Kg) and furosemide (2 mL/Kg) were simultaneously infused through the jugular vein to compensate hypernatremia. Changes in conductivity were monitored in the hepatic and tumour tissue. The period in which hepatic conductivity was higher than tumour conductivity was defined as the therapeutic window (TW). Animals were monitored during 1-month follow-up. The animals were sacrificed and selective samples were used for histological analysis. The overall survival rate was 82.4% after the HI protocol. The mean maximum hepatic conductivity after HI was 2.7 and 3.5 times higher than the baseline value, in group A and B, respectively. The mean maximum hepatic conductivity after HI was 1.4 times higher than tumour tissue in group B creating a TW to implement selective IRE. HI through the portal vein is safe when the hypersaline overload is compensated with deionized serum and it may provide a TW for focused IRE treatment on tumour nodules.

  5. Prokaryotic diversity and biogeochemical characteristics of benthic microbial ecosystems at La Brava, a hypersaline lake at Salar de Atacama, Chile.

    Directory of Open Access Journals (Sweden)

    Maria Eugenia Farias

    Full Text Available Benthic microbial ecosystems of Laguna La Brava, Salar de Atacama, a high altitude hypersaline lake, were characterized in terms of bacterial and archaeal diversity, biogeochemistry, (including O2 and sulfide depth profiles and mineralogy, and physicochemical characteristics. La Brava is one of several lakes in the Salar de Atacama where microbial communities are growing in extreme conditions, including high salinity, high solar insolation, and high levels of metals such as lithium, arsenic, magnesium, and calcium. Evaporation creates hypersaline conditions in these lakes and mineral precipitation is a characteristic geomicrobiological feature of these benthic ecosystems. In this study, the La Brava non-lithifying microbial mats, microbialites, and rhizome-associated concretions were compared to each other and their diversity was related to their environmental conditions. All the ecosystems revealed an unusual community where Euryarchaeota, Crenarchaeota, Acetothermia, Firmicutes and Planctomycetes were the most abundant groups, and cyanobacteria, typically an important primary producer in microbial mats, were relatively insignificant or absent. This suggests that other microorganisms, and possibly novel pathways unique to this system, are responsible for carbon fixation. Depth profiles of O2 and sulfide showed active production and respiration. The mineralogy composition was calcium carbonate (as aragonite and increased from mats to microbialites and rhizome-associated concretions. Halite was also present. Further analyses were performed on representative microbial mats and microbialites by layer. Different taxonomic compositions were observed in the upper layers, with Archaea dominating the non-lithifying mat, and Planctomycetes the microbialite. The bottom layers were similar, with Euryarchaeota, Crenarchaeota and Planctomycetes as dominant phyla. Sequences related to Cyanobacteria were very scarce. These systems may contain previously

  6. Assessment and management of dead-wood habitat

    Science.gov (United States)

    Hagar, Joan

    2007-01-01

    The Bureau of Land Management (BLM) is in the process of revising its resource management plans for six districts in western and southern Oregon as the result of the settlement of a lawsuit brought by the American Forest Resource Council. A range of management alternatives is being considered and evaluated including at least one that will minimize reserves on O&C lands. In order to develop the bases for evaluating management alternatives, the agency needs to derive a reasonable range of objectives for key issues and resources. Dead-wood habitat for wildlife has been identified as a key resource for which decision-making tools and techniques need to be refined and clarified. Under the Northwest Forest Plan, reserves were to play an important role in providing habitat for species associated with dead wood (U.S. Department of Agriculture Forest Service and U.S. Department of the Interior Bureau of Land Management, 1994). Thus, the BLM needs to: 1) address the question of how dead wood will be provided if reserves are not included as a management strategy in the revised Resource Management Plan, and 2) be able to evaluate the effects of alternative land management approaches. Dead wood has become an increasingly important conservation issue in managed forests, as awareness of its function in providing wildlife habitat and in basic ecological processes has dramatically increased over the last several decades (Laudenslayer et al., 2002). A major concern of forest managers is providing dead wood habitat for terrestrial wildlife. Wildlife in Pacific Northwest forests have evolved with disturbances that create large amounts of dead wood; so, it is not surprising that many species are closely associated with standing (snags) or down, dead wood. In general, the occurrence or abundance of one-quarter to one-third of forest-dwelling vertebrate wildlife species, is strongly associated with availability of suitable dead-wood habitat (Bunnell et al., 1999; Rose et al., 2001). In

  7. Ecophysiological plasticity of shallow and deep populations of the Mediterranean seagrasses Posidonia oceanica and Cymodocea nodosa in response to hypersaline stress.

    Science.gov (United States)

    Sandoval-Gil, Jose Miguel; Ruiz, Juan Manuel; Marín-Guirao, Lázaro; Bernardeau-Esteller, Jaime; Sánchez-Lizaso, Jose Luis

    2014-04-01

    The differential expression of the plant phenotypic plasticity due to inter- and intraspecific divergences can determine the plant physiological tolerance under stress. In this work, we examined the interspecific ecophysiological plasticity that the main Mediterranean seagrass species with distinct marine environmental distribution (Posidonia oceanica and Cymodocea nodosa) can exhibit in response to hypersaline stress. We also tested the potential implication of ecotypic intraspecific divergences in the development of such plasticities. To this end, plants from shallow (5-7 m) and deep (18-20 m) meadows of both were maintained under two salinity treatments (natural salinity level of 37, and hypersaline treatment of 43; Practical Salinity Scale) during a long-term experiment (i.e. 62 days) developed in a highly controlled mesocosm system. Hypersaline stress caused notable plastic physiological alterations in P. oceanica and C. nodosa, with appreciable inter- and intraspecific differences. Although both species were similarly able to osmoregulate by means of organic solute accumulation (proline and sugars) in response to hypersalinity stress, higher carbon balance reductions were detected in P. oceanica plants from the deep meadow and in shallower C. nodosa plants, due to both photosynthetic inhibition and enhancement of respiration. None of these deleterious effects were found in C. nodosa plants form the deeper meadow. Leaf photosynthetic pigments generally increased in P. oceanica from both depths, but light absorbance capacities by leaves and photosynthetic efficiency followed contrasting patterns, increasing and decreasing in plants from the deep and the shallow meadows, respectively, indicating distinct strategies to cope with photosynthetic dysfunctions. Despite the significant reduction of pigments in the shallower C. nodosa plants, their leaves were able to increase their light capture capacities under hypersaline stress, by means of particular leaf optics

  8. Deep-sea biodiversity in the Mediterranean Sea: the known, the unknown, and the unknowable.

    Directory of Open Access Journals (Sweden)

    Roberto Danovaro

    Full Text Available Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth, including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components

  9. Deep-sea biodiversity in the Mediterranean Sea: the known, the unknown, and the unknowable.

    Science.gov (United States)

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-08-02

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  10. DEAD-box proteins as RNA helicases and chaperones

    Science.gov (United States)

    Jarmoskaite, Inga; Russell, Rick

    2010-01-01

    DEAD-box proteins are ubiquitous in RNA-mediated processes and function by coupling cycles of ATP binding and hydrolysis to changes in affinity for single-stranded RNA. Many DEAD-box proteins use this basic mechanism as the foundation for a version of RNA helicase activity, efficiently separating the strands of short RNA duplexes in a process that involves little or no translocation. This activity, coupled with mechanisms to direct different DEAD-box proteins to their physiological substrates, allows them to promote RNA folding steps and rearrangements and to accelerate remodeling of RNA-protein complexes. This review will describe the properties of DEAD-box proteins as RNA helicases and the current understanding of how the energy from ATPase activity is used to drive the separation of RNA duplex strands. It will then describe how the basic biochemical properties allow some DEAD-box proteins to function as chaperones by promoting RNA folding reactions, with a focus on the self-splicing group I and group II intron RNAs. PMID:21297876

  11. Indoor Dead Reckoning Localization Using Ultrasonic Anemometer with IMU

    Directory of Open Access Journals (Sweden)

    Woojin Seo

    2017-01-01

    Full Text Available Dead reckoning is an important aspect of estimating the instantaneous position of a mobile robot. An inertial measurement unit (IMU is generally used for dead reckoning because it measures triaxis acceleration and triaxis angular velocities in order to estimate the position of the mobile robot. Positioning with inertial data is reasonable for a short period of time. However, the velocity, position, and attitude errors increase over time. Much research has been conducted in ways to reduce these errors. To position a mobile robot, an absolute positioning method can be combined with dead reckoning. The performance of a combined positioning method can be improved based on improvement in dead reckoning. In this paper, an ultrasonic anemometer is used to improve the performance of dead reckoning when indoors. A new approach to the equation of an ultrasonic anemometer is proposed. The ultrasonic anemometer prevents divergence of the mobile robot’s velocity. To position a mobile robot indoors, the ultrasonic anemometer measures the relative movement of air while the robot moves through static air. Velocity data from the ultrasonic anemometer and the acceleration and angular velocity data from the IMU are combined via Kalman filter. Finally we show that the proposed method has the performance with a positioning method using encoders on a good floor condition.

  12. Structural and isotopic analysis of kerogens in sediments rich in free sulfurised Botryococcus braunii biomarkers

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Grice, K.; Schouten, S.; Blokker, P.; Derenne, S.; Largeau, C.; Nissenbaum, A.

    2003-01-01

    Type I kerogens of two relatively immature, unusual hypersaline sediments [with extracts rich in sulfurised Botryococcus braunii (B. braunii) biomarkers] of Miocene/Pliocene age from the Sdom Formation (Dead Sea, Israel), have been investigated using a variety of organic geochemical techniques. Py

  13. Deadly Choices empowering Indigenous Australians through social networking sites.

    Science.gov (United States)

    McPhail-Bell, Karen; Appo, Nathan; Haymes, Alana; Bond, Chelsea; Brough, Mark; Fredericks, Bronwyn

    2017-04-05

    The potential for health promotion through social networking sites (SNSs) is widely recognized. However, while health promotion prides itself in focusing on the social determinants of health, its partiality for persuading individuals to comply with health behaviours dominates the way health promotion utilizes SNSs. This paper contributes to an understanding of collaborative ways SNSs can work for health promotion agendas of self-determination and empowerment in an Indigenous Australia context. An ethnographic study was undertaken with Deadly Choices, an Indigenous-led health promotion initiative. The study involved participant observation of interactions on Deadly Choices SNSs between Deadly Choices and its online community members. Deadly Choices provides an example of SNSs providing a powerful tool to create a safe, inclusive and positive space for Indigenous people and communities to profile their healthy choices, according to Indigenous notions of health and identity. The study found five principles that underpin Deadly Choices' use of SNSs for health promotion. These are: create a dialogue; build community online and offline; incentivise healthy online engagement; celebrate Indigenous identity and culture; and prioritize partnerships. Deadly Choices SNSs empowers Indigenous people and communities to be health promoters themselves, which represents a power shift from health promotion practitioner to Indigenous people and communities and more broadly, an enactment of Indigenous self-determination on SNSs. Mainstream health promotion can learn from Indigenous health promotion practice regarding the use of SNSs for health promotion agendas. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Homer and the cult of the dead in Helladic times

    Directory of Open Access Journals (Sweden)

    Odysseus Tsagarakis

    1980-12-01

    Full Text Available This paper discusses the Homeric bothros (Odyssey X 517 ff. as a possible source of information for the ritual and function of various bothroi (grave pits which are considered to be an important archaeological source. It seems that the bothroi were, by their nature, best suited to a cult of the dead and served as altars. The paper also discusses the possible reasons for the existence of the cult and argues against the view that fear of the dead motivated the cult in Helladic times.

  15. Intrapulmonary gas mixing and dead space in artificially ventilated dogs.

    Science.gov (United States)

    Schrikker, A C; Wesenhagen, H; Luijendijk, S C

    1995-09-01

    In this study we have investigated the effects of breath holding and of the physical properties of gases on four different respiratory dead spaces (VD): the Fowler, the physiological, the washout and the inert gas dead space. The experiments were performed with dogs which were ventilated artificially with breathing patterns with different post-inspiratory breath holding times (ta) of 0, 0.5, 1.0 and 2.0 s. Tracer amounts of acetone, ether and enflurane were infused continuously into a peripheral vein and a bolus of a mixture of krypton, Freon12 and SF6 was introduced into the peritoneal cavity. After reaching steady state, samples of arterial blood, mixed venous blood and mixed expired air were taken simultaneously. From the partial pressures (Pa, PV and PE respectively) we determined the excretion (E = PE/PV), retention (R = Pa/PV) and the physiological dead space fraction (VD,phys/VT = (1- PE/Pa)) for each gas, where VT is tidal volume. Further, we recorded the expirograms of the six tracer gases and of CO2 from which the Fowler dead space fractions (VD,Fowler/VT) of the different gases were determined. Also the washout dead space fractions (VD,washout/VT) for He and SF6 were determined as well as the inert gas dead space fraction (VD,MIGET/VT) with the use of the multiple inert gas elimination technique (MIGET). With the exception of VD,phys/VT for SF6, all dead space fractions decreased with increasing ta. VD,phys/VT for the poorly soluble gas SF6 was considerably larger than VD,phys/VT for the remaining gases. For the highly soluble acetone VFowler/VT was considerably smaller than VD,Fowler/VT for the other gases. VD,washout,SF6/VT was always larger than VD,washout,He/VT and VD,Fowler,SF6/VT. Further, VD,phys/VT was larger than VD,Fowler/VT for SF6 and acetone. However, for gases with intermediate solubility in blood VD,phys/VT tended to be smaller than VD,Fowler/VT. We conclude that the respiratory dead spaces are affected by the breathing pattern and by the

  16. Diversity of ribulose-1,5-bisphosphate carboxylase/oxygenase large-subunit genes in the MgCl2-dominated deep hypersaline anoxic basin discovery

    NARCIS (Netherlands)

    van der Wielen, PWJJ

    Partial sequences of the form I (cbbL) and form II (cbbM) of the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) large subunit genes were obtained from the brine and interface of the MgCl2-dominated deep hypersaline anoxic basin Discovery. CbbL and cbbM genes were found in both brine and

  17. Interconnections at the microbial and societal scales: The response of hypersaline microbial communities to environmental perturbations and a situated exercise in the democratization of science

    OpenAIRE

    Andrade, Karen

    2015-01-01

    AbstractInterconnections at the microbial and societal scales: The response of hypersaline microbial communities to environmental perturbations and a situated exercise in the democratization of sciencebyKaren AndradeDoctor of Philosophy in Environmental Science, Policy, and ManagementUniversity of California, BerkeleyProfessor Jillian F. Banfield, Co-ChairProfessor Alastair T. Iles, Co-ChairRegardless of the scale at which it is defined, at the core of a community is the interdependence and ...

  18. Ingestion of marine debris by loggerhead sea turtles, Caretta caretta, in the Adriatic Sea

    OpenAIRE

    Lazar, Bojan; Gračan, Romana

    2013-01-01

    We examined the occurrence of marine debris in the gastrointestinal tract of 54 loggerhead sea turtles (Caretta caretta) found stranded or incidentally captured dead by fisheries in the Adriatic Sea, with a curved carapace length of 25.0-79.2 cm. Marine debris was present in 35.2% of turtles and included soft plastic, ropes, Styrofoam and monofilament lines found in 68.4%, 42.1%, 15.8% and 5.3% of loggerheads that have ingested debris, respectively. The dry mass of debris per turtle was low, ...

  19. New Testament Textual Criticism is dead! Long live New Testament ...

    African Journals Online (AJOL)

    This article explores the notion that some of the basic assumptions upon which textual criticism is built, like the quest for an “original text”, have serious flaws and that much of what has been attempted the last 300 years is actually an exercise in futility. In this sense New Testament textual criticism can be declared dead.

  20. Pablo Remembers: The Fiesta of the Day of the Dead.

    Science.gov (United States)

    Ancona, George

    This children's book describes how Pablo, a young Mexican boy, and his family celebrate the Day of the Dead (El Dia de Los Muertos). This holiday takes place on the first and second day of November and honors relatives and friends who have died. The holiday celebrates their spiritual return to Earth to share a special feast with the living, and…

  1. Assessment of biofuel potential of dead neem leaves (Azadirachta ...

    African Journals Online (AJOL)

    TIZE

    2016-08-24

    Aug 24, 2016 ... the forest in the Sahel region. Therefore, the surface area which could be preserved through the year and in 10 years is illustrated in Table 3. From Table 3, the valorisation of the biogas as cooking energy from dead neem biomass quantified in Maroua town could allow the preservation of 567.45 ha/year of.

  2. Skeletal muscle mitochondrial respiration in AMPKa2 kinase dead mice

    DEFF Research Database (Denmark)

    Larsen, Steen; Kristensen, Jonas Møller; Stride, Nis

    2012-01-01

    AIM: To study if the phenotypical characteristics (exercise intolerance; reduced spontaneous activity) of the AMPKa2 kinase-dead (KD) mice can be explained by a reduced mitochondrial respiratory flux rates (JO(2) ) in skeletal muscle. Secondly, the effect of the maturation process on JO(2...

  3. Giving Thanks: Observing Thanksgiving, Kwanzaa, and Day of the Dead.

    Science.gov (United States)

    Dever, Martha T.; Barta, James J.

    1997-01-01

    Describes a primary-grade curriculum unit organized around the theme of "giving thanks" and encompassing the holidays of Thanksgiving, Kwanzaa, and Day of the Dead. Provides historical background and cultural context for each holiday, engagement activities, investigation activities, sharing activities, and a short list of related…

  4. Comparison of burning characteristics of live and dead chaparral fuels

    Science.gov (United States)

    L. Sun; X. Zhou; S. Mahalingam; D.R. Weise

    2006-01-01

    Wildfire spread in living vegetation, such as chaparral in southern California, often causes significant damage to infrastructure and ecosystems. The effects of physical characteristics of fuels and fuel beds on live fuel burning and whether live fuels differ fundamentally from dead woody fuels in their burning characteristics are not well understood. Toward this end,...

  5. Personal Reflection: Teaching in the Shadow of a Dead God

    Science.gov (United States)

    Corrigan, Paul T.

    2013-01-01

    Potter (2013) argues that even though many college teachers have adopted constructivist practices and perspectives, the "foundations" of Western higher education remain objectivist through and through. In the title metaphor of his essay, "objectivism" is the dead god. Constructivism killed it conceptually. But materially and…

  6. Gastric necrosis four years after fundoplication causing a dead foetus

    DEFF Research Database (Denmark)

    Thinggaard, Ebbe; Skovsen, Anders Peter; Kildsig, Jeppe

    2014-01-01

    A 31-year-old pregnant woman was admitted and treated for diabetic ketoacidosis. As the patient deteriorated and the viability of the foetus was uncertain a CT scan was done which showed free fluid and air intraabdominally. Surgery was performed. A dead foetus was delivered and a 2 × 5 cm necrotic...

  7. Dead Metaphor in Selected Advertisements in Nigerian Dailies ...

    African Journals Online (AJOL)

    Dead metaphors and images are often enlivened and empowered by advertisers to help their commUlzication and to achieve bewitching effects. It is interesting to see words and phrases that may be presumed to have been drained of their linguistic strength being brought back to currency and made to act fast in aiding ...

  8. Dynamic optimization of dead-end membrane filtration

    NARCIS (Netherlands)

    Blankert, B.; Betlem, Bernardus H.L.; Roffel, B.; Marquardt, Wolfgang; Pantelides, Costas

    2006-01-01

    An operating strategy aimed at minimizing the energy consumption during the filtration phase of dead-end membrane filtration has been formulated. A method allowing fast calculation of trajectories is used to allow incorporation in a hierarchical optimization scheme. The optimal trajectory can be

  9. Simulating psychophysical tuning curves in listeners with dead regions

    NARCIS (Netherlands)

    Warnaar, Bastiaan; Jepsen, Morten L.; Dreschler, Wouter A.

    2013-01-01

    This study investigates the relation between diagnosis of dead regions based on the off-frequency psychophysical tuning curve (PTC) tip and the frequency and level of the probe tone. A previously developed functional model of auditory processing was used to simulate the complete loss of inner hair

  10. Remembering Important People On The Day Of The Dead

    Science.gov (United States)

    Curriculum Review, 2005

    2005-01-01

    This article describes a project that can help students learn more about historic figures-or remember lost loved ones--with this Day of the Dead project from Frida Kahlo and Diego Rivera. The purpose is to remember the wonderful things the person did, and to celebrate his or her life. Directions for construction, as well as a suggested list of…

  11. The permeability of dead plant cells for some enzymes

    NARCIS (Netherlands)

    Gorin, N.

    1969-01-01

    The penetration of α-chymotrypsin and/or pancreatic lipase into dead cells of soybean cotyledons, of yeast and of algae was studied using the enzymic activity as a parameter. In addition a fluorescent antibody technique was applied for the localization of α-chymotrypsin within the soybean

  12. "The Northern Lights" Investigative Reporting Covers Deadly Decisions.

    Science.gov (United States)

    Srour, George

    2001-01-01

    Presents a story package from the high school newspaper "The Northern Lights," called "Deadly Decisions." Includes an editorial, an eyewitness account, a timeline of the coverage itself, an interview with a local TV reporter, photographs, and a graph of the events the stories covered. (SR)

  13. Assessment of biofuel potential of dead neem leaves ( Azadirachta ...

    African Journals Online (AJOL)

    Dead leaves of neem trees in the Sahelian urban zone are among the wastes that are underutilized, since it is either buried or burnt, and thus, contribute to increased environmental pollution. Unfortunately, the lack of information on the biomass and energy potentials of these wastes empedes any initiative for its industrial ...

  14. Bacteria of living and dead larvae of Porthetria dispar (L.)

    Science.gov (United States)

    John D. Podgwaite; Benjamin J. Cosenza

    1966-01-01

    A preliminary study of the bacteria associated with living and dead larvae of the gypsy moth (Porthetria dispar (L.)) was undertaken to determine what types of micro-organisms may be associated with disease in this insect. Specific objectives of this study were to enumerate the types of aerobic bacteria, and if possible to further elucidate the role...

  15. On H∞ control for dead-time systems

    NARCIS (Netherlands)

    Meinsma, Gjerrit; Zwart, Heiko J.

    2000-01-01

    A mixed sensitivity H∞ problem is solved for dead-time systems. It is shown that for a given bound on the H∞-norm causal stabilizing controllers exist that achieve this bound if and only if a related finite-dimensional Riccati equation has a solution with a certain nonsingularity property. In the

  16. Michoacan People, Customs, and the Day of the Dead.

    Science.gov (United States)

    Maulhardt, Mary

    This curriculum guide is intended: (1) to expose students to the people and customs of Michoacan, Mexico; (2) to explore the meaning of traditional Day of the Dead customs through hands-on experiences; and (3) to build the self-esteem of second language learners of Mexican descent. During the study, students whose primary language is Spanish read…

  17. [Forensic Analysis of 20 Dead Cases Related to Heroin Abuse].

    Science.gov (United States)

    Huang, W Q; Li, L H; Li, Z; Hong, S J

    2016-08-01

    To perform retrospective analysis on 20 dead cases related to heroin abuse, and to provide references for the forensic assessment of correlative cases. Among 20 dead cases related to heroin abuse, general situation, using method of drug, cause of death and result of forensic examination were analyzed by statistical analysis for summarizing the cause of death and pathologic changes. The dead were mostly young adults, with more male than female. The results of histopathological examinations showed non-specific pathological changes. There were four leading causes of death, including acute poisoning of heroin abuse or leakage (13 cases, 65%), concurrent diseases caused by heroin abuse (3 cases, 15%), inspiratory asphyxia caused by taking heroin (2 cases, 10%), and heroin withdrawal syndrome (2 cases, 10%). The forensic identification on dead related to heroin abuse must base on the comprehensive autopsy, and combine with the qualitative and quantitative analysis of heroin and its metabolites in death and the case information, as well as the scene investigation.

  18. Eating the dead in Madagascar | Campbell | South African Medical ...

    African Journals Online (AJOL)

    It was, for example, noted in Madagascar during the imperial campaigns of Ranavalona I in the period 1829 - 1853. Two types of cannibalism have been described: exocannibalism, where enemies were consumed, and endocannibalism, where dead relatives were eaten to assist their passing to the world of the ancestors, ...

  19. Bipolar disorder, childhood bereavement, and the return of the dead ...

    African Journals Online (AJOL)

    Upon its head, with red extended mouth and solitary eye of fire, sat the hideous beast whose craft had seduced me into murder ...' From 'The Black Cat', written c. age 35 (Poe 1975:230). Keywords: Edgar Allan Poe; bipolar disorder, childhood bereavement, and the return of the dead; literary criticism; American poetry; ...

  20. Hypoalbuminaemia in brain-dead donors for liver transplantation

    African Journals Online (AJOL)

    Nicky

    We retrospectively reviewed the charts of the 37 brain-dead patients referred to the organ transplant unit at Groote. Schuur Hospital in 2001 and 2002 as potential donors for liver transplantation. All potential donors were assessed, investigated and man- aged according to standard protocols. The assessment con- sisted of ...

  1. After continents divide: Comparative phylogeography of reef fishes from the Red Sea and Indian Ocean

    KAUST Repository

    Dibattista, Joseph D.

    2013-01-07

    Aim: The Red Sea is a biodiversity hotspot characterized by a unique marine fauna and high endemism. This sea began forming c. 24 million years ago with the separation of the African and Arabian plates, and has been characterized by periods of desiccation, hypersalinity and intermittent connection to the Indian Ocean. We aim to evaluate the impact of these events on the genetic architecture of the Red Sea reef fish fauna. Location: Red Sea and Western Indian Ocean. Methods: We surveyed seven reef fish species from the Red Sea and adjacent Indian Ocean using mitochondrial DNA cytochrome c oxidase subunit I and cytochrome b sequences. To assess genetic variation and evolutionary connectivity within and between these regions, we estimated haplotype diversity (h) and nucleotide diversity (π), reconstructed phylogenetic relationships among haplotypes, and estimated gene flow and time of population separation using Bayesian coalescent-based methodology. Results: Our analyses revealed a range of scenarios from shallow population structure to diagnostic differences that indicate evolutionary partitions and possible cryptic species. Conventional molecular clocks and coalescence analyses indicated time-frames for divergence between these bodies of water ranging from 830,000 years to contemporary exchange or recent range expansion. Colonization routes were bidirectional, with some species moving from the Indian Ocean to the Red Sea compared with expansion out of the Red Sea for other species. Main conclusions: We conclude that: (1) at least some Red Sea reef fauna survived multiple salinity crises; (2) endemism is higher in the Red Sea than previously reported; and (3) the Red Sea is an evolutionary incubator, occasionally contributing species to the adjacent Indian Ocean. The latter two conclusions - elevated endemism and species export - indicate a need for enhanced conservation priorities for the Red Sea. © 2013 Blackwell Publishing Ltd.

  2. SlDEAD31, a Putative DEAD-Box RNA Helicase Gene, Regulates Salt and Drought Tolerance and Stress-Related Genes in Tomato.

    Directory of Open Access Journals (Sweden)

    Mingku Zhu

    Full Text Available The DEAD-box RNA helicases are involved in almost every aspect of RNA metabolism, associated with diverse cellular functions including plant growth and development, and their importance in response to biotic and abiotic stresses is only beginning to emerge. However, none of DEAD-box genes was well characterized in tomato so far. In this study, we reported on the identification and characterization of two putative DEAD-box RNA helicase genes, SlDEAD30 and SlDEAD31 from tomato, which were classified into stress-related DEAD-box proteins by phylogenetic analysis. Expression analysis indicated that SlDEAD30 was highly expressed in roots and mature leaves, while SlDEAD31 was constantly expressed in various tissues. Furthermore, the expression of both genes was induced mainly in roots under NaCl stress, and SlDEAD31 mRNA was also increased by heat, cold, and dehydration. In stress assays, transgenic tomato plants overexpressing SlDEAD31 exhibited dramatically enhanced salt tolerance and slightly improved drought resistance, which were simultaneously demonstrated by significantly enhanced expression of multiple biotic and abiotic stress-related genes, higher survival rate, relative water content (RWC and chlorophyll content, and lower water loss rate and malondialdehyde (MDA production compared to wild-type plants. Collectively, these results provide a preliminary characterization of SlDEAD30 and SlDEAD31 genes in tomato, and suggest that stress-responsive SlDEAD31 is essential for salt and drought tolerance and stress-related gene regulation in plants.

  3. Distinctive Microbial Community Structure in Highly Stratified Deep-Sea Brine Water Columns

    KAUST Repository

    Bougouffa, Salim

    2013-03-29

    Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools.

  4. Smoking Out a Deadly Threat: Tobacco Use in the LGBT Community

    Science.gov (United States)

    ... Out a Deadly Threat: Tobacco Use in the LGBT Community Disparities in Lung Health Series "Smoking Out a Deadly Threat: Tobacco Use in the LGBT Community" is part of the American Lung Association's ...

  5. Analysis of archaeal communities in Gulf of Mexico dead zone sediments.

    Science.gov (United States)

    Sediments may contribute significantly to Louisiana continental shelf “dead zone” hypoxia but limited information hinders comparison of sediment biogeochemistry between norm-oxic and hypoxic seasons. Dead zone sediment cores collected during hypoxia (September 2006) had higher l...

  6. Use of 13C-Labeled Substrates to Determine Relative Methane Production Rates in Hypersaline Microbial Communities

    Science.gov (United States)

    Kelley, C. A.; Bebout, B.; Chanton, J.

    2015-12-01

    Rates and pathways of methane production were determined from photosynthetic soft microbial mats and gypsum-encrusted endoevaporites collected in hypersaline environments from California, Mexico and Chile, as well as an organic-rich mud from a pond in the El Tatio volcanic fields, Chile. Samples (mud, homogenized soft mats and endoevaporites) were incubated anaerobically with deoxygenated site water, and the increase in methane concentration through time in the headspaces of the incubation vials was used to determine methane production rates. To ascertain the substrates used by the methanogens, 13C-labeled methylamines, methanol, dimethylsulfide, acetate or bicarbonate were added to the incubations (one substrate per vial) and the stable isotopic composition of the resulting methane was measured. The vials amended with 13C-labeled methylamines produced the most 13C-enriched methane, generally followed by the 13C-labeled methanol-amended vials. The stable isotope data and the methane production rates were used to determine first order rate constants for each of the substrates at each of the sites. Estimates of individual substrate use revealed that the methylamines produced 55 to 92% of the methane generated, while methanol was responsible for another 8 to 40%.

  7. New insights into microbially induced sedimentary structures in alkaline hypersaline El Beida Lake, Wadi El Natrun, Egypt

    Science.gov (United States)

    Taher, Amany G.; Abdel-Motelib, Ali

    2015-10-01

    Microbially induced sedimentary structures (MISS) were studied in detail in the alkaline hypersaline El Beida Lake of Wadi El Natrun in the western desert sector of Egypt, based on field observations and sampling performed in 2013 and 2014. Geomorphologically, the lake can be subdivided into three zones, each with characteristic sedimentary and biosedimentary structures. The marginal elevated zone that borders the lake is characterized by thick blocky crusts devoid of microbial mats. The middle-lower supratidal zone has luxuriant microbial mats associated with knotty surfaces, mat cracks and wrinkle structures. A zone of ephemeral shallow pools and channels is characterized by reticulate surfaces, pinnacle mats, sieve-like surfaces, gas domes and mat chips. In the microbial mats, authigenic minerals include thenardite Na2SO4, trona Na3(CO3)(HCO3)•2H2O and halite NaCl. Scanning electron microscopy (SEM) analyses revealed that the minerals are closely associated with the MISS, suggesting some influence of microorganisms on mineral precipitation. Complex interactions between regional hydrological cycles and diagenetic processes imply low preservation potential. MISS signatures of such saline lakes can serve as key analogues for interpreting the geologic record.

  8. Complete denitrification in coculture of obligately chemolithoautotrophic haloalkaliphilic sulfur-oxidizing bacteria from a hypersaline soda lake.

    Science.gov (United States)

    Sorokin, Dimitry Y; Antipov, Alexey N; Kuenen, J Gijs

    2003-08-01

    Eight anaerobic enrichment cultures with thiosulfate as electron donor and nitrate as electron acceptor were inoculated with sediment samples from hypersaline alkaline lakes of Wadi Natrun (Egypt) at pH 10; however, only one of the cultures showed stable growth with complete nitrate reduction to dinitrogen gas. The thiosulfate-oxidizing culture subsequently selected after serial dilution developed in two phases. Initially, nitrate was mostly reduced to nitrite, with a coccoid morphotype prevailing in the culture. During the second stage, nitrite was reduced to dinitrogen gas, accompanied by mass development of thin motile rods. Both morphotypes were isolated in pure culture and identified as representatives of the genus Thioalkalivibrio, which includes obligately autotrophic sulfur-oxidizing haloalkaliphilic species. Nitrate-reducing strain ALEN 2 consisted of large nonmotile coccoid cells that accumulated intracellular sulfur. Its anaerobic growth with thiosulfate, sulfide, or polysulfide as electron donor and nitrate as electron acceptor resulted in the formation of nitrite as the major product. The second isolate, strain ALED, was able to grow anaerobically with thiosulfate as electron donor and nitrite or nitrous oxide (but not nitrate) as electron acceptor. Overall, the action of two different sulfur-oxidizing autotrophs resulted in the complete, thiosulfate-dependent denitrification of nitrate under haloalkaliphilic conditions. This process has not yet been demonstrated for any single species of chemolithoautotrophic sulfur-oxidizing haloalkaliphiles.

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Dominik Schneider

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

  11. Natronospira proteinivora gen. nov., sp. nov, an extremely salt-tolerant, alkaliphilic gammaproteobacterium from hypersaline soda lakes.

    Science.gov (United States)

    Sorokin, Dimitry Y; Kublanov, Ilya V; Khijniak, Tatiana V

    2017-08-01

    Brine samples from Kulunda Steppe soda lakes (Altai, Russia) were inoculated into a hypersaline alkaline mineral medium with β-keratin (chicken feather) as a substrate. The micro-organisms dominating the enrichment culture were isolated by limiting serial dilution on the same medium with casein as a substrate. The cells of strain BSker1T were motile, curved rods. The strain was an obligately aerobic heterotroph utilizing proteins and peptides as growth substrates. The isolate was an obligate alkaliphile with a pH range for growth from pH 8.5 to 10.25 (optimum at pH 9.5), and it was extremely salt tolerant, growing with between 1 and 4.5 M total Na+ (optimally at 2-2.5 M). BSker1T had a unique composition of polar lipid fatty acids, dominated by two C17 species. The membrane polar lipids included multiple unidentified phospholipids and two aminolipids. According to phylogenetic analysis of the 16S rRNA gene sequence, the isolate forms a novel branch within the family Ectothiorhodospiraceae (class Gammaproteobacteria) with the highest sequence similarity to the members of this family being 91 %. On the basis of distinct phenotypic and genotypic properties, strain BSker1T (=JCM 31341T=UNIQEM U1008T) is proposed to be classified as a representative of a novel genus and species, Natronospira proteinivora gen. nov., sp. nov.

  12. Desulfonatronobacter acetoxydans sp. nov.,: a first acetate-oxidizing, extremely salt-tolerant alkaliphilic SRB from a hypersaline soda lake.

    Science.gov (United States)

    Sorokin, D Y; Chernyh, N A; Poroshina, M N

    2015-09-01

    Recent intensive microbiological investigation of sulfidogenesis in soda lakes did not result in isolation of any pure cultures of sulfate-reducing bacteria (SRB) able to directly oxidize acetate. The sulfate-dependent acetate oxidation at haloalkaline conditions has, so far, been only shown in two syntrophic associations of novel Syntrophobacteraceae members and haloalkaliphilic hydrogenotrophic SRB. In the course of investigation of one of them, obtained from a hypersaline soda lake in South-Western Siberia, a minor component was observed showing a close relation to Desulfonatronobacter acidivorans--a "complete oxidizing" SRB from soda lakes. This organism became dominant in a secondary enrichment with propionate as e-donor and sulfate as e-acceptor. A pure culture, strain APT3, was identified as a novel member of the family Desulfobacteraceae. It is an extremely salt-tolerant alkaliphile, growing with butyrate at salinity up to 4 M total Na(+) with a pH optimum at 9.5. It can grow with sulfate as e-acceptor with C3-C9 VFA and also with some alcohols. The most interesting property of strain APT3 is its ability to grow with acetate as e-donor, although not with sulfate, but with sulfite or thiosulfate as e-acceptors. The new isolate is proposed as a new species Desulfonatronobacter acetoxydans.

  13. Two-dimensional mapping of photopigment distribution and activity of Chloroflexus-like bacteria in a hypersaline microbial mat.

    Science.gov (United States)

    Bachar, Ami; Polerecky, Lubos; Fischer, Jan P; Vamvakopoulos, Kyriakos; de Beer, Dirk; Jonkers, Henk M

    2008-09-01

    Pigment analysis in an intact hypersaline microbial mat by hyperspectral imaging revealed very patchy and spatially uncorrelated distributions of photopigments Chl a and BChl a/c, which are characteristic photopigments for oxygenic (diatoms and cyanobacteria) and anoxygenic phototrophs (Chloroflexaceae). This finding is in contrast to the expectation that these biomarker pigments should be spatially correlated, as oxygenic phototrophs are thought to supply the Chloroflexaceae members with organic substrates for growth. We suggest that the heterogeneous occurrence is possibly due to sulfide, whose production by sulfate-reducing bacteria may be spatially heterogeneous in the partially oxic photic zone of the mat. We furthermore mapped the near-infra-red-light controlled respiration of Chloroflexaceae under light and dark conditions and found that Chloroflexaceae are responsible for a major part of oxygen consumption at the lower part of the oxic zone in the mat. The presence of Chloroflexaceae was further confirmed by FISH probe and 16S rRNA gene clone library analysis. We assume that species related to the genera Oscillochloris and 'Candidatus Chlorothrix', in contrast to those related to Chloroflexus and Roseiflexus, depend less on excreted photosynthates but more on the presence of free sulfide, which may explain their presence in deeper parts of the mat.

  14. 20 CFR 404.721 - Evidence to presume a person is dead.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Evidence to presume a person is dead. 404.721... person is dead. If you cannot prove the person is dead but evidence of death is needed, we will presume... person is presumed to be dead as set out in Federal law (5 U.S.C. 5565). Unless we have other evidence...

  15. Quantifying Responses of Spectral Vegetation Indices to Dead Materials in Mixed Grasslands

    OpenAIRE

    Xiaohui Yang; Xulin Guo

    2014-01-01

    Spectral vegetation indices have been the primary resources for characterizing grassland vegetation based on remotely sensed data. However, the use of spectral indices for vegetation characterization in grasslands has been challenged by the confounding effects from external factors, such as soil properties, dead materials, and shadowing of vegetation canopies. Dead materials refer to the dead component of vegetation, including fallen litter and standing dead grasses accumulated from previous ...

  16. Phylogenetic Distribution and Evolutionary History of Bacterial DEAD-Box Proteins

    OpenAIRE

    López-Ramírez, Varinia; Alcaraz, Luis D; Moreno-Hagelsieb, Gabriel; Olmedo-Álvarez, Gabriela

    2011-01-01

    DEAD-box proteins are found in all domains of life and participate in almost all cellular processes that involve RNA. The presence of DEAD and Helicase_C conserved domains distinguish these proteins. DEAD-box proteins exhibit RNA-dependent ATPase activity in vitro, and several also show RNA helicase activity. In this study, we analyzed the distribution and architecture of DEAD-box proteins among bacterial genomes to gain insight into the evolutionary pathways that have shaped their history. W...

  17. Characterization and impact of "dead-zone" eddies in the tropical Northeast Atlantic Ocean

    Science.gov (United States)

    Schuette, Florian; Karstensen, Johannes; Krahmann, Gerd; Hauss, Helena; Fiedler, Björn; Brandt, Peter; Visbeck, Martin; Körtzinger, Arne

    2016-04-01

    Localized open-ocean low-oxygen dead-zones in the tropical Northeast Atlantic are recently discovered ocean features that can develop in dynamically isolated water masses within cyclonic eddies (CE) and anticyclonic modewater eddies (ACME). Analysis of a comprehensive oxygen dataset obtained from gliders, moorings, research vessels and Argo floats shows that eddies with low oxygen concentrations at 50-150 m depths can be found in surprisingly high numbers and in a large area (from about 5°N to 20°N, from the shelf at the eastern boundary to 30°W). Minimum oxygen concentrations of about 9 μmol/kg in CEs and close to anoxic concentrations (dead-zone" eddies (10 CEs; 17 ACMEs). The low oxygen concentration right beneath the mixed layer has been attributed to the combination of high productivity in the surface waters of the eddies and the isolation of the eddies' cores. Indeed eddies of both types feature a cold sea surface temperature anomaly and enhanced chlorophyll concentrations in their center. The oxygen minimum is located in the eddy core beneath the mixed layer at around 80 m depth. The mean oxygen anomaly between 50 to 150 m depth for CEs (ACMEs) is -49 (-81) μmol/kg. Eddies south of 12°N carry weak hydrographic anomalies in their cores and seem to be generated in the open ocean away from the boundary. North of 12°N, eddies of both types carry anomalously low salinity water of South Atlantic Central Water origin from the eastern boundary upwelling region into the open ocean. This points to an eddy generation near the eastern boundary. A conservative estimate yields that around 5 dead-zone eddies (4 CEs; 1 ACME) per year entering the area north of 12°N between the Cap Verde Islands and 19°W. The associated contribution to the oxygen budget of the shallow oxygen minimum zone in that area is about -10.3 (-3.0) μmol/kg/yr for CEs (ACMEs). The consumption within these eddies represents an essential part of the total consumption in the open tropical

  18. Development of glassy carbon electrode (Dead Sea scroll) for low energy cardiac pacing.

    Science.gov (United States)

    Katsumoto, K; Niibori, T; Takamatsu, T; Kaibara, M

    1986-11-01

    We have developed a new type of glassy carbon electrode whose smooth surface with scattered craters reduces its polarization voltage. It has both excellent antithrombogenicity and slight tissue reaction. The energy threshold curve was the lowest when compared to the Siemens (411S, 412S) and the Solin (S-100) electrodes.

  19. Orphans in the Dead Sea Scrolls | Kotzé | HTS Teologiese Studies ...

    African Journals Online (AJOL)

    This study investigates the literary references to orphans in writings amongst the Qumran texts that were written in Hebrew and can be associated with the sectarian Qumran movement. The study focuses on passages where forms of the word יתום are used. These include the Damascus Document (CD 6:16–17), Hodayot ...

  20. The First Jewish Astronomers: Lunar Theory and Reconstruction of a Dead Sea Scroll.

    Science.gov (United States)

    Ratzon, Eshbal

    2017-06-01

    Argument The Astronomical Book of Enoch describes the passage of the moon through the gates of heaven, which stand at the edges of the earth. In doing so, the book describes the position of the rising and setting of the moon on the horizon. Otto Neugebauer, the historian of ancient science, suggested using the detailed tables found in later Ethiopic texts in order to reconstruct the path of the moon through the gates. This paper offers a new examination of earlier versions of the Astronomical Book, using a mathematical analysis of the figures and astronomical theories presented throughout the Aramaic Astronomical Book; the results fit both the data preserved in the scrolls and the mathematical approach and religious ideology of the scroll's authors better than the details found in the late Ethiopic texts. Among other new insights, this alternate theory also teaches about the process of the composition of the Astronomical Book in the first centuries of its composition.

  1. THE PERMIAN -TRIASSIC BOUNDARY, DEAD SEA, JORDAN: TRANSITIONAL ALLUVIAL TO MARINE DEPOSITIONAL SEQUENCES AND BIOSTRATIGRAPHY

    Directory of Open Access Journals (Sweden)

    JOHN H. POWELL

    2016-10-01

    Full Text Available The Permian to Triassic transition in Jordan is characterised by a sequence boundary underlain by red-bed, alluvial lithofacies deposited in a humid-tropical climate by low-sinuosity rivers, and overlain by shallow marine siliciclastics with thin carbonates. The low-gradient alluvial floodplain was repeatedly subjected to the development of ferralitic and pisolitic paleosols on the interfluves. In contrast, dysaerobic environments in the fluvial channels and abandoned lakes resulted in the preservation of a prolific flora of macro-plants and palynomorphs that indicate a probable range from Mid- to Late Permian age, though the abundant presence of the distinctive pollen Pretricolpipollenites bharadwajii  indicates the youngest part of that range.  Above the sequence boundary, reddened shallow-marine beds characterised by ripple cross-laminated, siltstones/sandstone with desiccation cracks and sparse surface burrows mark the initial Triassic marine transgression in the region (Arabian Plate Tr 10. These are followed by two thin limestone (packstone beds with shallow scours and bivalve shell lags, that have yielded a low diversity assemblage of conodonts (e.g. Hadrodontina aequabilis and foraminifera (“Cornuspira” mahajeri that are interpreted as euryhaline  taxa characterising the early Induan (Early Triassic. Thus the absence of body fossils and vertical infaunal burrows in the lowest marine beds may reflect low-diversity ecosystems following the Permian-Triassic extinction event, or be a result of stressed shallow marine environments. A gradational upward increase in grey, green and yellow siltstones beds accompanied by a concomitant increase in bioturbation (and infaunal vertical burrows and thin-shelled bivalves about 15 m above the boundary indicates colonisation of the substrate under more normal shallow marine conditions perhaps indicating recovery phase following the extinction event.

  2. Sulphur bath and mud pack treatment for rheumatoid arthritis at the Dead Sea area.

    Science.gov (United States)

    Sukenik, S; Buskila, D; Neumann, L; Kleiner-Baumgarten, A; Zimlichman, S; Horowitz, J

    1990-02-01

    Forty patients with classical or definite rheumatoid arthritis in a stage of active disease were treated for two weeks at a spa hotel. The patients were divided into four groups of 10. Group I was treated with daily mud packs, group II with daily hot sulphur baths, group III with a combination of mud packs and hot sulphur baths, and group IV served as a control group. The patients were assessed by a rheumatologist who was blinded to the treatment modalities. Statistically significant improvement for a period of up to three months was observed in the three treatment groups in most of the clinical indices. Improvement in the control group was minor in comparison and not statistically significant. No significant improvement was observed in any of the laboratory variables measured. Except for three mild cases of thermal reaction there were no side effects.

  3. stylistic variation in three english translations of the dead sea scrolls

    African Journals Online (AJOL)

    admin

    J. A. Naudé, Department of Afroasiatic Studies, Sign Language and Lan- ... the nature and scope of this corpus are discussed elsewhere (e.g., Naudé 2004). ..... sectarian theology and customs; therefore, we can describe this library as a sectarian library. All the manuscripts found in the caves belong to the same library.

  4. El Dia de los Muertos -- Libreto. (The Day of the Dead -- Notebook.)

    Science.gov (United States)

    Espinoza, Delia; Lopez, Santiago, III

    On November 2, all Mexican Americans remember their dead as Mexico does on that same day. Called "El Dia de los Muertos" (Day of the Dead), the dead are remembered posthumously with flowers, candles, music, prayers, chants, and wreaths. The people go to cemeteries to clean tombs, lay fresh or artificial flowers on them, and pray for…

  5. 9 CFR 309.3 - Dead, dying, disabled, or diseased and similar livestock.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Dead, dying, disabled, or diseased and... AND VOLUNTARY INSPECTION AND CERTIFICATION ANTE-MORTEM INSPECTION § 309.3 Dead, dying, disabled, or diseased and similar livestock. (a) Livestock found to be dead or in a dying condition on the premises of...

  6. Microclimate and habitat heterogeneity as the major drivers of beetle diversity in dead wood

    Science.gov (United States)

    Sebastian Seibold; Claus Bassler; Roland Brandl; Boris Buche; Alexander Szallies; Simon Thorn; Michael D. Ulyshen; Jorg Muller; Christopher Baraloto

    2016-01-01

    1. Resource availability and habitat heterogeneity are principle drivers of biodiversity, but their individual roles often remain unclear since both factors are usually correlated. The biodiversity of species dependent on dead wood could be driven by either resource availability represented by dead-wood amount or habitat heterogeneity characterized by dead-wood...

  7. Proportional Derivative Control with Inverse Dead-Zone for Pendulum Systems

    OpenAIRE

    Rubio, José de Jesús; Zamudio, Zizilia; Pacheco, Jaime; Mújica Vargas, Dante

    2013-01-01

    A proportional derivative controller with inverse dead-zone is proposed for the control of pendulum systems. The proposed method has the characteristic that the inverse dead-zone is cancelled with the pendulum dead-zone. Asymptotic stability of the proposed technique is guaranteed by the Lyapunov analysis. Simulations of two pendulum systems show the effectiveness of the proposed technique.

  8. 14 CFR 1203b.105 - Use of non-deadly physical force when making an arrest.

    Science.gov (United States)

    2010-01-01

    ... believes to be the use or threat of imminent use of non-deadly physical force by the offender. Verbal abuse... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Use of non-deadly physical force when... Use of non-deadly physical force when making an arrest. When a security force officer has the right to...

  9. Impact of accelerated future global mean sea level rise on hypoxia in the Baltic Sea

    Science.gov (United States)

    Meier, H. E. M.; Höglund, A.; Eilola, K.; Almroth-Rosell, E.

    2017-07-01

    Expanding hypoxia is today a major threat for many coastal seas around the world and disentangling its drivers is a large challenge for interdisciplinary research. Using a coupled physical-biogeochemical model we estimate the impact of past and accelerated future global mean sea level rise (GSLR) upon water exchange and oxygen conditions in a semi-enclosed, shallow sea. As a study site, the Baltic Sea was chosen that suffers today from eutrophication and from dead bottom zones due to (1) excessive nutrient loads from land, (2) limited water exchange with the world ocean and (3) perhaps other drivers like global warming. We show from model simulations for the period 1850-2008 that the impacts of past GSLR on the marine ecosystem were relatively small. If we assume for the end of the twenty-first century a GSLR of +0.5 m relative to today's mean sea level, the impact on the marine ecosystem may still be small. Such a GSLR corresponds approximately to the projected ensemble-mean value reported by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. However, we conclude that GSLR should be considered in future high-end projections (>+1 m) for the Baltic Sea and other coastal seas with similar hydrographical conditions as in the Baltic because GSLR may lead to reinforced saltwater inflows causing higher salinity and increased vertical stratification compared to present-day conditions. Contrary to intuition, reinforced ventilation of the deep water does not lead to overall improved oxygen conditions but causes instead expanded dead bottom areas accompanied with increased internal phosphorus loads from the sediments and increased risk for cyanobacteria blooms.

  10. Not to declare dead someone still alive: Case reports

    Directory of Open Access Journals (Sweden)

    Anđelić Slađana

    2015-01-01

    Full Text Available Introduction. Diagnosing death represents an activity that carries a great deal of public responsibility for medical professionals and is continually exposed to the control of citizens and media. Although this is a taboo subject in medical circles, unfortunately in medical practice there are situations when the physician issues a death diagnosis form without even examining the person or for an already buried person. Such physician’s action is impermissible and it leads to the possibility of professional and criminal law punishment. Case Outline. By giving examples from practice, we wish to point out the need for exceptional caution when confirming and diagnosing death in order to diagnose the true, i.e. rule out apparent death and consequently avoid the mistake of declaring dead someone still alive. Conclusion. When confirming and declaring death, exceptional caution of the physician is necessary so as not to declare dead someone still alive!

  11. Low-Dead-Volume Inlet for Vacuum Chamber

    Science.gov (United States)

    Naylor, Guy; Arkin, C.

    2011-01-01

    Gas introduction from near-ambient pressures to high vacuum traditionally is accomplished either by multi-stage differential pumping that allows for very rapid response, or by a capillary method that allows for a simple, single-stage introduction, but which often has a delayed response. Another means to introduce the gas sample is to use the multi-stage design with only a single stage. This is accomplished by using a very small conductance limit. The problem with this method is that a small conductance limit will amplify issues associated with dead-volume. As a result, a high-vacuum gas inlet was developed with low dead-volume, allowing the use of a very low conductance limit interface. Gas flows through the ConFlat flange at a relatively high flow rate at orders of magnitude greater than through the conductance limit. The small flow goes through a conductance limit that is a double-sided ConFlat.

  12. The Dead Mother, the Uncanny, and the Holy Ghost

    Directory of Open Access Journals (Sweden)

    Gal Ventura

    2015-01-01

    Full Text Available Recurrent portrayals of dead mothers frequently appeared in French art from 1800 to 1850. This essay focuses on one of the latest manifestations of this image, namely, the French Realist Jules Breton's (1827-1906 painting The Hunger of 1850, in order to examine the psycho-historical elements associated with the mother's death. Through an analysis of the "Uncanny" as formulated by both Ernst Jentsch and Sigmund Freud, we will address the undissolvable link between the structuralization of "homeliness" in the late eighteenth century and the dread it evoked in the early nineteenth century, as two sides of the same coin. We will simultaneously consider the inherent conflictuality embodied by the dead mother according to the French psychoanalyst André Green, who dealt with the experience of "nothingness" that characterizes children of mothers-who-refuse-to-die.

  13. Awakening the "Walking Dead": Zombie Pedagogy for Millennials

    Directory of Open Access Journals (Sweden)

    Nancy Dawn Wadsworth

    2017-02-01

    Full Text Available This article lays out the pedagogical benefits of using popular zombie productions, particularly AMC's The Walking Dead, to teach a critical introduction to modern political theory. Based on my undergraduate course: "Political Theory, Climate Change, and the Zombie Apocalypse," the article outlines how The Walking Dead can be used to critique the mythic assumptions built into modern social contract theory; to introduce other political ideologies, including conservatism, anarchism, fascism, and communism; and to consider the political challenges raised by a global problem such as climate change in an increasingly neoliberal environment. Zombie productions are offered as a particularly salient pedagogical tool that can help awaken critical political analysis for the Millennial Generation.

  14. Pulsed optically pumped atomic clock with zero-dead-time

    Science.gov (United States)

    Lin, Haixiao; Lin, Jinda; Deng, Jianliao; Zhang, Song; Wang, Yuzhu

    2017-12-01

    By alternatively operating two pulsed optically pumped (POP) atomic clocks, the dead time in a single clock can be eliminated, and the local oscillator can be discriminated continuously. A POP atomic clock with a zero-dead-time (ZDT) method is then insensitive to the microwave phase noise. From τ = 0.01 to 1 s, the Allan deviation of the ZDT-POP clock is reduced as nearly τ-1, which is significantly faster than τ-1/2 of a conventional clock. During 1-40 s, the Allan deviation returns to τ-1/2. Moreover, the frequency stability of the ZDT-POP clock is improved by one order of magnitude compared with that of the conventional POP clock. We also analyze the main factors that limit the short-term frequency stability of the POP atomic clock.

  15. The death effect in literary evaluation: reverence for the dead?

    Science.gov (United States)

    Green, Joseph P; Mohler, Eric W

    It is commonly believed that the value of art and other creative works increases after the death of the artist. In an attempt to examine this so-called death effect we presented a short story to N = 431 undergraduate students asking how much money they would hypothetically spend to purchase a literary work. We experimentally manipulated: 1) whether the author died or moved after publishing a short story, and, 2) the gender of the author. Participants randomly received one of four possible biographical descriptions about the author. We predicted that participants would offer higher purchase prices and subjectively evaluate the work more positively when they believed the author was dead. Results were consistent with this hypothesis perhaps reflecting a certain reverence for the dead. We also found that evaluations of the story were more favorable when the purported gender of the author matched that of the participant.

  16. A data-acquisition card without dead time

    CERN Document Server

    Nagy, J Z; Bottyan, L

    1999-01-01

    The knowledge of the ion beam profile in a storage ring is vital and it is measured by a position-sensitive detector. Co-ordinates of hit locations on the anodes of two multi-channel plate (MCP) detectors (one in horizontal and the other in vertical direction) are collected. Task sharing between software and hardware, including dual-buffer memory-management as implemented in the data-acquisition card described here, eliminates acquisition dead time.

  17. [Communication with the relatives of a patient presumed brain dead].

    Science.gov (United States)

    Kompanje, Erwin J O; de Groot, Yorick J; Ijzermans, Jan N M; Visser, Gerhard H; Bakker, Jan; van der Jagt, Mathieu

    2011-01-01

    The choice of wording in cases of suspected brain death is important. If brain death has not been proven by electrocerebral silence and by absence of spontaneous breathing in an apnoea test in a patient in intensive care, then words like 'brain dead', 'has died' and 'clinical brain death' should be avoided in conversations with the relatives of the patient. This is illustrated by three cases. The first patient was a 46-year-old woman, with thrombosis of the basilar artery; the second was a 26-year-old man who was resuscitated after a bilateral pneumothorax, but developed severe postanoxic encephalopathy; and the third patient was a 64-year-old man with a large intracerebral haemorrhage. The relatives were informed that the patient was 'brain dead' or 'deceased' based on loss of consciousness (Glasgow Coma score of 3) and absence of brain stem reflexes, but prior to the completion of the brain death protocol by electroencephalography and apnoea testing. In the first and third cases, brain death could not be proven, and the pronouncement that the patient was deceased had to be reversed. The emotional relatives refused organ donation. In the second case, death was pronounced upon loss of consciousness and absence of brain stem reflexes. The relatives refused organ donation, after which mechanical ventilation was withdrawn and the patient was declared dead for a second time based on circulatory arrest. A patient is dead after complete brain death determination or after circulatory arrest. Loss of consciousness (Glasgow Coma score of 3) and absence of brain stem reflexes lead to a state of catastrophic cerebral damage, but not to brain death. In such a situation, wording such as 'brain death', 'deceased' and 'clinical brain death' should be avoided in conversations with the relatives.

  18. [Serotonin dysfunctions in the background of the seven deadly sins].

    Science.gov (United States)

    Janka, Zoltán

    2003-11-20

    The symbolic characters of the Seven Deadly Sins can be traced from time to time in the cultural history of human mankind, being directly specified in certain artistic products. Such are, among others, the painting entitled "The Seven Deadly Sins and the Four Lost Things" by Hieronymus Bosch and the poems Divina Commedia and The Foerie Queene by Dante Alighieri and Edmund Spenser, respectively. However, there are several paragraphs referring to these behaviours of the Seven Deadly Sins in the Bible and in the dramas of William Shakespeare. The objective of the present review is to propose that dysfunctions in the central serotonergic system might be involved in the neurobiology of these 'sinful' behaviour patterns. Evidences indicate that behaviour traits such as Accidia (Sloth), Luxuria (Lust, Lechery), Superbia (Pride), Ira (Wrath, Anger), Invidia (Envy), Avaritia (Greed, Avarice), and Gula (Gluttony) can relate to the functional alterations of serotonin in the brain. Results of biochemical and molecular genetic (polymorphism) studies on the human serotonergic system (receptor, transporter, enzyme), findings of functional imaging techniques, effects of depletion (or supplementation) of the serotonin precursor tryptophan, data of challenge probe investigations directed to testing central serotonergic functions, alterations in the peripheral serotonin measures (platelet), and the changes in the CSF 5-hydroxy-indoleacetic acid content indicate such serotonergic involvement. Furthermore, results of animal experiments on behaviour change (aggressive, dominant or submissive, appetite, alcohol preference) attributed to serotonin status modification and the clinically evidenced therapeutic efficacy of pharmacological interventions, based on the modulation and perturbation of the serotonergic system (e.g. selective serotonin reuptake inhibitors), in treating the 'sinful' behaviour forms and analogous pathological states reaching the severity of psychiatric disorders

  19. Anencephalic donors: separate the dead from the dying.

    Science.gov (United States)

    Capron, A M

    1987-02-01

    Proposals to use organs from anencephalic infants to meet the growing need for transplantable organs are well-meaning but misguided. It would be unwise to amend the Uniform Determination of Death Act to classify anencephalics as "dead." They are in the same situation as other patients (such as the permanently comatose). Likewise, amending the Anatomical Gift Act to permit organs to be removed from anencephalics would be unjust, would set a bad precedent, and would likely reduce overall success in this field.

  20. Enrichment of extremophilic exoelectrogens in microbial electrolysis cells using Red Sea brine pools as inocula.

    Science.gov (United States)

    Shehab, Noura A; Ortiz-Medina, Juan F; Katuri, Krishna P; Hari, Ananda Rao; Amy, Gary; Logan, Bruce E; Saikaly, Pascal E

    2017-09-01

    Applying microbial electrochemical technologies for the treatment of highly saline or thermophilic solutions is challenging due to the lack of proper inocula to enrich for efficient exoelectrogens. Brine pools from three different locations (Valdivia, Atlantis II and Kebrit) in the Red Sea were investigated as potential inocula sources for enriching exoelectrogens in microbial electrolysis cells (MECs) under thermophilic (70°C) and hypersaline (25% salinity) conditions. Of these, only the Valdivia brine pool produced high and consistent current 6.8±2.1A/m2-anode in MECs operated at a set anode potential of +0.2V vs. Ag/AgCl (+0.405V vs. standard hydrogen electrode). These results show that exoelectrogens are present in these extreme environments and can be used to startup MEC under thermophilic and hypersaline conditions. Bacteroides was enriched on the anode of the Valdivia MEC, but it was not detected in the open circuit voltage reactor seeded with the Valdivia brine pool. Copyright © 2017 Elsevier Ltd. All rights reserved.