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Sample records for occurrences palaeoenvironments taphonomy

  1. Fossil-bearing deposits from the Bukpyeong Formation (Miocene) in the Bukpyeong Basin at Donghae city, Gangwon-do, South Korea: occurrences, taphonomy and paleoenvironmental implications

    NASA Astrophysics Data System (ADS)

    Kim, Hyun Joo; Jeong, Eun Kyoung; Uemura, Kazuhiko; Kim, Kyungsik; Paik, In Sung

    2016-04-01

    Abundant and diverse plant fossils such as land plants and subaqueous plants, freshwater mollusc fossils and invertebrate trace fossils are found in the Miocene Bukpyeong Formation at Donghae city, Gangwon-do, South Korea. Occurrences and taphofacies of the fossil-bearing deposits from the Bukpyeong Formation are described and their taphonomy and paleoenvironmental implications are interpreted. Based on fossil occurrences, lithofacies and sedimentary features of the fossil-bearing deposits, eight taphofacies are classified as the following: (1) Taphofacies 1: Gastropod fossils in massive silty mudstone; (2) Taphofacies 2: Bivalve fossils in massive silty mudstone; (3) Taphofacies 3: Plant fossils (leaf fossils) in massive silty mudstone; (4) Taphofacies 4: Gastropod and plant fossils in massive silty mudstone; (5) Taphofacies 5: Plant fossils in weakly fissile silty mudstone; (6) Taphofacies 6: Plant fossils (leaf fossils) in thin-bedded and graded silty mudstone to mudstone (claystone); (7) Taphofacies 7: Plant fragment fossils in thin-bedded and graded silty mudstone to mudstone (claystone); (8) Taphofacies 8: Plant debris in planar- to cross-laminated fine-grained sandstone. Taphonomy of taphofacies 1, 2, and 4 including freshwater mollusc fossils is interpreted to have been reworked or transported by turbidity currents after death and deposited in shallow lake to open lake. Taphonomy of taphofacies 3, 5, 6, and 7 including plant fossils is interpreted to have been transported by input of episodic flooding in the land and deposited by settling down in open lake. Taphofacies 8 including plant debris has been deposited in shallow lake by input of intensive episodic flooding from the land. The occurrences and taphofacies of the fossil-bearing deposits indicate that most of the fossils were transported by turbidity current induced by input of episodic flooding in the land and deposited in shallow lake to open lake. Moreover, plant fossils from the Bukpyeong

  2. Palaeoenvironments and hominoid evolution.

    PubMed

    Pickford, Martin

    2002-03-01

    One of the key features that separates humans and their closest relatives (extinct species of the genus Homo and Praeanthropus and the australopithecines Australopithecus and Paranthropus) on the one hand, from the other hominoids, on the other, is their obligate bipedal locomotion when on the ground. This major difference from the generally quadrupedal locomotion practiced by other hominoids (Pan, Gorilla, Pongo and many extinct lineages) is reflected in many parts of the body, including all the major bones in the legs, arms, trunk and cranium. Locomotion has thus been of major interest to those interested in human origins, evolution, classification and phylogeny. A major hurdle to studies of the origins of bipedalism concerns the paucity of African hominoid fossils between 15 Ma, when all the adequately known hominoids were quadrupedal (most were pronograde, but at least one lineage was orthograde), and 4.2 Ma by which time fully bipedal hominids were established in Africa. Examination of Old World geology and palaeontology reveals a great deal about the evolution of palaeoenvironments and faunas during this period, and it is suggested that hominids evolved bipedal locomotion at the same time that there was a fundamental reorganisation of faunas towards the end of the Miocene. This faunal turnover resulted in the establishment of faunal lineages of "modern" aspect in Africa at the expense of "archaic" lineages which either went extinct or suffered a diminution of diversity. Many of the "modern" lineages were adapted to open country habitats in which grass became a major component of the diet as shown by modifications in the cheek teeth. Hominoids, in contrast, retained their traditional diet but were obliged to forage over greater and greater areas in order to do so, and this tactic led to pressures to modify the locomotor system rather than the diet. If bipedal hominids originated during this period, then the family Hominidae (sensu stricto) dates from about 8

  3. The Late Pleistocene Duoi U'Oi cave in northern Vietnam: palaeontology, sedimentology, taphonomy and palaeoenvironments

    NASA Astrophysics Data System (ADS)

    Bacon, Anne-Marie; Demeter, F.; Duringer, P.; Helm, C.; Bano, M.; Vu, The Long; Kim Thuy, Nguyen Thi; Antoine, P.-O.; Thi Mai, Bui; Huong, Nguyen Thi Mai; Dodo, Y.; Chabaux, F.; Rihs, S.

    2008-08-01

    This paper describes new fossil materials recovered at the Duoi U'Oi site, in December 2003, by a Vietnamese-French-Japanese team. The Duoi U'Oi cave is located in Man Duc village, 25 km of Hoà Binh city in northern Vietnam. It belongs to a karstic network developed in a dark grey micritic marine limestone dated from the Lower to the Middle Triassic. The sedimentary fill produced a rich mammalian fauna, essentially composed of isolated teeth of middle- to large-sized mammals (Artiodactyla, Perissodactyla, Proboscidea, Carnivora, Rodentia, Primates), and characteristic of Late Pleistocene. The results of the Duoi U'Oi fieldwork are of great interest for the following reasons: (1) the biochronological age of the fauna is consistent with 230Th/ 234U/ 238U dating from the calcitic floors (66±3 ka). The Duoi U'Oi fauna is thus the oldest well-dated modern fauna known for the Southeast Asian mainland; (2) in terms of sedimentology, the analysis of the formation of the fossiliferous breccia and that of the processes of deposits shows a close relation between the karstic deposits inside the cave and the deposits in the alluvial terraces. The observation of three levels of alluvial terraces associated with three caves situated at 62, 10 and 3 m above the present alluvial plain suggests that exokarstic and endokarstic sediments evolved together; (3) in terms of palaeobiogeography, Duoi U'Oi is the continental fauna showing the strongest resemblance with the Late Pleistocene faunas from Indonesian islands (Punung, Gunung Dawung, Lida Ajer, Sibrambang and Djambu caves); this implies that, at the time of Duoi U'Oi, ca 70 ka, the Sundaland was mainly characterised by faunas of modern aspect; (4) the analysis of major taphonomic factors that led to the mammal assemblage reveals a combination of selective agents (selective role of predators and porcupines, selective destruction of age classes for some species, selective preservation of fossils due to the deposition processes in the karstic network), which contribute to the poor representation of the diversity of the fauna; no arguments show that humans, present at Duoi U'Oi, might have a possible role in the taphonomic process; (5) the palaeoenvironmental reconstruction based on the composition of the faunal assemblage suggests a forested area and some open habitats, under warm and humid conditions.

  4. Geology and taphonomy of the base of the Taquaral Member, Irati Formation (Permian, Paraná Basin), Brazil

    NASA Astrophysics Data System (ADS)

    Chahud, Artur; Petri, Setembrino

    2015-09-01

    The taphonomy of Early Permian vertebrates from a sandy facies at the base of the Taquaral Member, Irati Formation, was surveyed in order to acquire data for the interpretation of the sedimentary processes and paleoenvironment of deposition. Six outcrops from the Rio Claro municipality and surrounding areas, from the Brazilian State of São Paulo, were investigated. The vertebrate groups are Chondrichthyes (Xenacanthiformes, Ctenacanthiformes and Petalodontiformes), Osteichthyes (Actinopterygii and Sarcopterygii) and Tetrapodomorpha. They occur as loose teeth, scales, spines and bone remains. The sandy facies is characterized by fining upward deposition. The coarser sandstone immediately above the underlying Tatuí Formation is rich in Chondrichthyes. However, the fine sandstone above, immediately beneath the silty shale facies, is devoid of Chondrichthyes, though Osteichthyes scales, teeth and bones were present. The taphonomy is important for inferring sedimentary processes and then the paleoenvironments. The poor sorting of the sandstone and the presence of fossils that are mostly abraded or worn are indicative of a high energy environment. In contrast, the presence of fossils in a good state of preservation, some without abrasion and breakages are indicative of only limited transport. Differences of fossil spatial density, numbers of specimens and taxa may be explained by the dynamics of deposition, from details of the palaeoenvironment can be obtained.

  5. The ichnogenus Rhizocorallium: Classification, trace makers, palaeoenvironments and evolution

    NASA Astrophysics Data System (ADS)

    Knaust, Dirk

    2013-11-01

    Rhizocorallium is one of the oldest known trace fossils, with wide distribution through the Phanerozoic and all over the world. Originally introduced from the epicontinental Triassic of central Germany, its high morphological lability gave reason for the subsequent erection of about twenty ichnospecies. The study of newly collected material from the type area and many specimens from various collections permits the conclusion that Rhizocorallium jenense and Rhizocorallium commune are the only valid ichnospecies of Rhizocorallium. The type ichnospecies, R. jenense, is a comparatively small, inclined and heavily scratched firmground burrow with passive fill, while R. commune consists of extensive, more or less horizontal burrows with occasionally scratched marginal tubes and an actively filled spreite between the tubes. The faecal pellets Coprulus oblongus are typically associated with R. commune. Morphological variations of R. commune are captured in ichnosubspecies and varieties of this ichnospecies and can aid a refined reconstruction of palaeoenvironments. A review of more than 180 records from the literature reveals the common confusion of both ichnospecies, which has consequences for the application of Rhizocorallium in facies interpretations. The end members of both ichnospecies may be linked by transitional forms, which suggests the same kind of trace maker. Polychaetes are the most likely producers of marine Rhizocorallium, based on their long-ranging occurrence, morphological features, appearance of faecal pellets, associated soft-body remains, and modern analogues. R. commune occurs from Early Cambrian to Holocene, while R. jenense just appears after the end-Permian mass extinction, probably as a consequence of an adapted firmground burrowing lifestyle of its producer. Fluvial R. jenense are probably produced by mayfly larvae in homology to marine polychaete burrows. A consequent application of the newly established classification scheme allows for a more

  6. The Lower Jurassic of the Eastern Caspian region and the Middle Caspian Basin: Lithology, facies, taphonomy

    NASA Astrophysics Data System (ADS)

    Kiritchkova, A. I.; Nosova, N. V.

    2014-09-01

    Lithofacies of the productive Upper Triassic-Lower Jurassic deposits of the Eastern Caspian region, studied in wells on the Caspian coast and exposed in the outcrops of the Mountainous Mangyshlak, are described and analyzed. The similarity of the structure of the Mesozoic sedimentary beds of the Middle Caspian Basin and of those of the land adjacent to its eastern coast is confirmed. Comparative analysis of lithofacies allowed the reconstruction of the paleogeographic setting and depositional environments in the studied region during the Early Jurassic. A unique fossil plant occurrence is discovered in the upper part of the Lower Jurassic series (in the lower subformation of the Kokala Formation; Eastern Caspian region). Fossil plant taphonomy and the lithology of host rocks in the occurrence resulted from unusual paleogeographic settings that existed in the Middle Caspian Basin at the time of the Early-Middle Jurassic boundary.

  7. The Cenozoic palaeoenvironment of the Arctic Ocean

    USGS Publications Warehouse

    Moran, K.; Backman, J.; Brinkhuis, H.; Clemens, S.C.; Cronin, T.; Dickens, G.R.; Eynaud, F.; Gattacceca, J.; Jakobsson, M.; Jordan, R.W.; Kaminski, M.; King, J.; Koc, N.; Krylov, A.; Martinez, N.; Matthiessen, J.; McInroy, D.; Moore, T.C.; Onodera, J.; O'Regan, M.; Palike, H.; Rea, B.; Rio, D.; Sakamoto, T.; Smith, D.C.; Stein, R.; St, John K.; Suto, I.; Suzuki, N.; Takahashi, K.; Watanabe, M. E.; Yamamoto, M.; Farrell, J.; Frank, M.; Kubik, P.; Jokat, W.; Kristoffersen, Y.

    2006-01-01

    The history of the Arctic Ocean during the Cenozoic era (0-65 million years ago) is largely unknown from direct evidence. Here we present a Cenozoic palaeoceanographic record constructed from >400 m of sediment core from a recent drilling expedition to the Lomonosov ridge in the Arctic Ocean. Our record shows a palaeoenvironmental transition from a warm 'greenhouse' world, during the late Palaeocene and early Eocene epochs, to a colder 'icehouse' world influenced by sea ice and icebergs from the middle Eocene epoch to the present. For the most recent ???14 Myr, we find sedimentation rates of 1-2 cm per thousand years, in stark contrast to the substantially lower rates proposed in earlier studies; this record of the Neogene reveals cooling of the Arctic that was synchronous with the expansion of Greenland ice (???3.2 Myr ago) and East Antarctic ice (???14 Myr ago). We find evidence for the first occurrence of ice-rafted debris in the middle Eocene epoch (???45 Myr ago), some 35 Myr earlier than previously thought; fresh surface waters were present at ???49 Myr ago, before the onset of ice-rafted debris. Also, the temperatures of surface waters during the Palaeocene/Eocene thermal maximum (???55 Myr ago) appear to have been substantially warmer than previously estimated. The revised timing of the earliest Arctic cooling events coincides with those from Antarctica, supporting arguments for bipolar symmetry in climate change. ?? 2006 Nature Publishing Group.

  8. The Cenozoic palaeoenvironment of the Arctic Ocean.

    PubMed

    Moran, Kathryn; Backman, Jan; Brinkhuis, Henk; Clemens, Steven C; Cronin, Thomas; Dickens, Gerald R; Eynaud, Frédérique; Gattacceca, Jérôme; Jakobsson, Martin; Jordan, Richard W; Kaminski, Michael; King, John; Koc, Nalan; Krylov, Alexey; Martinez, Nahysa; Matthiessen, Jens; McInroy, David; Moore, Theodore C; Onodera, Jonaotaro; O'Regan, Matthew; Pälike, Heiko; Rea, Brice; Rio, Domenico; Sakamoto, Tatsuhiko; Smith, David C; Stein, Ruediger; St John, Kristen; Suto, Itsuki; Suzuki, Noritoshi; Takahashi, Kozo; Watanabe, Mahito; Yamamoto, Masanobu; Farrell, John; Frank, Martin; Kubik, Peter; Jokat, Wilfried; Kristoffersen, Yngve

    2006-06-01

    The history of the Arctic Ocean during the Cenozoic era (0-65 million years ago) is largely unknown from direct evidence. Here we present a Cenozoic palaeoceanographic record constructed from >400 m of sediment core from a recent drilling expedition to the Lomonosov ridge in the Arctic Ocean. Our record shows a palaeoenvironmental transition from a warm 'greenhouse' world, during the late Palaeocene and early Eocene epochs, to a colder 'icehouse' world influenced by sea ice and icebergs from the middle Eocene epoch to the present. For the most recent approximately 14 Myr, we find sedimentation rates of 1-2 cm per thousand years, in stark contrast to the substantially lower rates proposed in earlier studies; this record of the Neogene reveals cooling of the Arctic that was synchronous with the expansion of Greenland ice (approximately 3.2 Myr ago) and East Antarctic ice (approximately 14 Myr ago). We find evidence for the first occurrence of ice-rafted debris in the middle Eocene epoch (approximately 45 Myr ago), some 35 Myr earlier than previously thought; fresh surface waters were present at approximately 49 Myr ago, before the onset of ice-rafted debris. Also, the temperatures of surface waters during the Palaeocene/Eocene thermal maximum (approximately 55 Myr ago) appear to have been substantially warmer than previously estimated. The revised timing of the earliest Arctic cooling events coincides with those from Antarctica, supporting arguments for bipolar symmetry in climate change.

  9. The taphonomy of human remains in a glacial environment.

    PubMed

    Pilloud, Marin A; Megyesi, Mary S; Truffer, Martin; Congram, Derek

    2016-04-01

    A glacial environment is a unique setting that can alter human remains in characteristic ways. This study describes glacial dynamics and how glaciers can be understood as taphonomic agents. Using a case study of human remains recovered from Colony Glacier, Alaska, a glacial taphonomic signature is outlined that includes: (1) movement of remains, (2) dispersal of remains, (3) altered bone margins, (4) splitting of skeletal elements, and (5) extensive soft tissue preservation and adipocere formation. As global glacier area is declining in the current climate, there is the potential for more materials of archaeological and medicolegal significance to be exposed. It is therefore important for the forensic anthropologist to have an idea of the taphonomy in this setting and to be able to differentiate glacial effects from other taphonomic agents. PMID:26917542

  10. Quartz grain assessment for reconstructing the coastal palaeoenvironment

    NASA Astrophysics Data System (ADS)

    Vieira Machado, Giseli Modolo; Albino, Jacqueline; Leal, Arthur Pereira; Bastos, Alex Cardoso

    2016-10-01

    This study proposes a combination of sedimentological techniques as a tool to understand depositional palaeoenvironments. Grain size, mineralogy, compositional data, stratigraphic framework, degree of rounding, optical appearance and microtextures of quartz grains were analyzed; sub-surface sediments were collected from 4 boreholes spaced across coastal settings, from the beach towards the continent, from locations on the south-central coast of the state of Espírito Santo, southeast Brazil. Five palaeoenvironments were identified: fluvial (characterized by gravelly sand facies, composed predominantly of sub-angular and sub-rounded dirty quartz grains with microtexures caused by sudden impact and grain surfaces modified by chemical action, as well as other non-quartz terrigenous minerals); continental deposit with marine influence, such as an estuary (characterized by muddy sand facies, composed of immature grains with natural glow and non-abraded grains with a "fresh" clean surface, little to no chemical change, a few bioclastic fragments, carbonate nodules and grains embedded with carbonate); modern estuary (characterized by sandy mud facies, composed of mixed mature and immature quartz grains, chemically frosted, bioclastic fragments, carbonate nodules, and high organic matter content); bay (characterized by sandy mud and mud facies, composed predominantly of mature grains, highly chemically frosted, with microtextures clearly associated with post-depositional alteration, many bioclastic fragments, and organic matter); and beach (characterized by gravelly sand facies, composed predominantly of sub-rounded dirty grains, followed by shiny grains, with smooth edges, signs of former impact, little chemical dissolution on the quartz grain, and bioclastic fragments). The association between the degree of rounding, optical aspect and microtextures of quartz grains was essential to estimate the extent and strength of seawater intrusion in filling of the sedimentation

  11. Taphonomy for taxonomists: Implications of predation in small mammal studies

    NASA Astrophysics Data System (ADS)

    Fernández-Jalvo, Yolanda; Andrews, Peter; Denys, Christiane; Sesé, Carmen; Stoetzel, Emmanuelle; Marin-Monfort, Dolores; Pesquero, Dolores

    2016-05-01

    Predation is one of the most recurrent sources of bone accumulations. The influence of predation is widely studied for large mammal sites where humans, acting as predators, produce bone accumulations similar to carnivore accumulations. Similarly, small mammal fossil sites are mainly occupation levels of predators (nests or dens). In both cases, investigations of past events can be compared with present day equivalents or proxies. Chewing marks are sometimes present on large mammal predator accumulations, but digestion traits are the most direct indication of predation, and evidence for this is always present in small mammal (prey) fossil assemblages. Digestion grades and frequency indicates predator type and this is well established since the publication of Andrews (1990). The identification of the predator provides invaluable information for accurate interpretation of the palaeoenvironment. Traditionally, palaeoenvironmental interpretations are obtained from the taxonomic species identified in the site, but rather than providing direct interpretations of the surrounding palaeoenvironment, this procedure actually describes the dietary preferences of the predators and the type of occupation (nests, marking territory, dens, etc). This paper reviews the identification of traits produced by predators on arvicolins, murins and soricids using a method that may be used equally by taxonomists and taphonomists. It aims to provide the "tools" for taxonomists to identify the predator based on their methodology, which is examining the occlusal surfaces of teeth rather than their lateral aspects. This will greatly benefit both the work of taphonomists and taxonomists to recognize signs of predation and the improvement of subsequent palaeoecological interpretations of past organisms and sites by identifying both the prey and the predator.

  12. Taphonomy of rhodoliths as determined by constructional and destructional processes

    NASA Astrophysics Data System (ADS)

    Nitsch, Florian; Nebelsick, James; Bassi, Davide

    2015-04-01

    Rhodoliths made up primarily of self encrusting coralline algae are important contributors to Cenozoic carbonates and can be used as ecological indicators following taxonomic make up, encrustation patterns and growth form morphologies. Relatively few studies have been con-ducted on the taphonomy of rhodoliths with respect to their preservation potentials and how this affects our knowledge of carbonate production. In this study an actualistic approach is used assessing the production and destruction of rhodoliths derived from the Island of Giglio (Tyrrhenian Sea, Italy). These rhodoliths are studied with regard to shape, growth-forms and taxonomy of the constructing fauna, presence and degree of porosity and types of void for-mation. Techniques used include sectioning and micro-computed tomography (micro-CT) enabling the recognition of different void types on different scales as well as their distribu-tions. The rhodoliths are spheroidal to sub-spheroidal in shape and reach sizes up to to 13 cm in length. They are dominated by coralline red algae though the skeletons of other components especially bryozoans and serpulid worm tubes contribute to the nodules. Porosity values up to 41 % in volume were measured consisting of three different types of voids: Primary voids are represented by single cells of the algae; constructional voids are caused by amalgamated protuberances of coralline algae thalli; destructional voids are produced by dissolution of nucleus as well as potential soft bodied animals contributing to the rhodoliths and by a wide range of bioerosion types including Trypanites and Gastrochaenolites ichnotaxa.

  13. Lake Prespa palaeoenvironment since the MIS 5: a continuous record from a mid-altitude site on modern human's way to Europe.

    NASA Astrophysics Data System (ADS)

    Panagiotopoulos, K.; Aufgebauer, A.; Schäbitz, F.; Wagner, B.

    2012-04-01

    Lake Prespa is situated in the Balkans (40°57'50'' N, 20°58'41'' E) along the eastern trajectory of modern human dispersal. A long (c. 18m) composite sediment core was investigated using geophysical, geochemical and pollen analyses. This study aims to reconstruct the palaeoenvironment and palaeoclimate from a mid-altitude (849m asl) site and evaluate their implications in the migration of our ancestors from Africa to Europe. The age-depth model, based on radiocarbon dating and tephrochronology, indicates continuous sedimentation reaching back to MIS 5. According to the pollen record, the wider Lake Prespa catchment sustained refugial temperate tree populations throughout this period. Following the decline of woodlands at the end of MIS 5, pollen concentration and TOC percentages retain relatively low values until the onset of the Holocene when closed forest formations dominated the landscape signaling the establishment of a warmer and moister climate. Distinct fluctuations of arboreal relative percentages coupled with the occurrence of TIC and Mn peaks can be tentatively correlated to Heinrich events. Climatic oscillations are sensitively recorded in the Lake Prespa sediments at a sub-millennial scale permitting a detailed reconstruction of the regional palaeoenvironment, as well as correlations with other regional and global climate archives. This project is part of the Collaborative Research Center 806: "Our Way To Europe; Culture-Environment Interaction and Human Mobility in the Late Quaternary" (www.sfb806.de). Keywords: Lake Prespa, Balkans, eastern Mediterranean, pollen analysis, palaeolimnology, modern human dispersal

  14. The anatomy, taphonomy, taxonomy and systematic affinity of Markuelia: Early Cambrian to Early Ordovician scalidophorans

    USGS Publications Warehouse

    Dong, X.-P.; Bengtson, S.; Gostling, N.J.; Cunningham, J.A.; Harvey, T.H.P.; Kouchinsky, A.; Val'Kov, A.K.; Repetski, J.E.; Stampanoni, M.; Marone, F.; Donoghue, P.C.J.

    2010-01-01

    Markuelia is a vermiform, annulated introvertan animal known as embryonic fossils from the Lower Cambrian to Lower Ordovician. Analysis of an expanded and revised dataset for Introverta shows that the precise position of Markuelia within this clade is dependent on the taxa included. As a result, Markuelia is assigned to the scalidophoran total group to reflect uncertainty as to whether it is a stem-scalidophoran or a stem-priapulid. The taxonomy of the genus is revised to provide an improved taxonomic framework for material assigned to Markuelia. Five species are recognized: M. secunda Val'kov, M. hunanensis Dong and Donoghue, M. lauriei Haug et al., M. spinulifera sp. nov. and M. waloszeki sp. nov. Finally, the preservation of Markuelia is evaluated in the light of both the taphonomy of the fossil embryos themselves and the experimental taphonomy of the priapulid Priapulus caudatus, which has been proposed as both a close relative and an anatomical analogue of Markuelia. ?? The Palaeontological Association.

  15. Experimental taphonomy of velvet worms (Onychophora) and implications for the Cambrian "explosion, disparity and decimation" model.

    PubMed

    Monge-Nájera, Julián; Hou, Xianguang

    2002-01-01

    Experimental preservation of velvet worms (phylum Onychophora), a very rare but evolutionarily important group that has existed for more than 500 million years, showed that the absence of bucal parts, adhesive-expelling organs, gonopore, eyes, legs, claws, annulation and papillation in fossils may not represent absence in the living animals. In fossils, leg thickness and claw orientation can be unreliable. The experiments indicate that not only absence, but even presence of certain structures can simply be the result of tissue decomposition. Computer-aided photorealistic reconstructions of fossi onychophorans are presented. We recommend future researchers to conduct taphonomy experiments specially before analysing unusual fossils.

  16. Palynostratigraphy, palynofacies and palaeoenvironment of deposition of Selandian to Aquitanian sediments, southeastern Nigeria

    NASA Astrophysics Data System (ADS)

    Okeke, Kingsley K.; Umeji, Obianuju P.

    2016-08-01

    Investigation of outcrop sections along the Onitsha-Awka transect in the Niger Delta Basin southeastern Nigeria was undertaken to assess the palynological composition, palynofacies and palaeoenvironment of deposition. Stratigraphic ranges of palynomorphs suggest an age of Selandian to Aquitanian. The palynological composition is marked by abundance of dinoflagellate cysts in the Imo Formation (Selandian to Thanetian), dominance of spores and pollen over dinoflagellate cysts in the Nanka Formation (Ypresian to Bartonian), and overwhelming amounts of spore and pollen in the Ogwashi Formation (Pariabonian to Aquitanian). Palynofacies content shows dominance of structureless organic matter in the Imo Formation, few phytoclasts in the Nanka Formation and maximum phytoclast amounts in the Ogwashi Formation. Thanetian to Ypresian boundary was marked by the mixing of older Palaeocene and younger Eocene microfossils, decrease of microflora towards the end of Palaeocene and the evolution of abundant and more diverse Eocene taxa. The Imo Formation was deposited in middle to outer neritic zone based on abundance of gonyaulacacean cysts. However, peridiniacean and terrestrial microflora extend the deposition range to shallow waters of inner neritic and coastal zone. Increase in diversity and abundance of terrestrial palynomorphs over marine palynomorphs assemblages in the overlying Nanka Formation suggest deposition under alternating coastal and inner neritic conditions while the Ogwashi Formation records oscillating coastal plain and brackish water depositional conditions. The palaeoenvironments illustrate that general retrogradation was followed by progradation of the delta during the Cenozoic.

  17. Stratigraphy, palaeoenvironments and palaeoecology of the Loch Humphrey Burn lagerstätte and other Mississippian palaeobotanical localities of the Kilpatrick Hills, southwest Scotland

    PubMed Central

    Stevens, Liadan G.; Hilton, Jason

    2016-01-01

    Background and Aims. The largely Mississippian strata of the Kilpatrick Hills, located at the western end of the Scottish Midland Valley, enclose several macrofossil floras that together contain ca 21 organ-species of permineralised plants and ca 44 organ-species of compressed plants, here estimated to represent 25 whole-plant species (Glenarbuck = nine, Loch Humphrey Burn Lower = 11, Upper = seven). The most significant locality is the internationally important volcanigenic sequence that is reputedly intercalated within the Clyde Plateau Lava Formation at Loch Humphrey Burn, where ca 30 m of reworked tuffs and other clastic sediments enclose one of the world’s most important terrestrial lagerstätten of this period. We here explore the palaeoecology and palaeoenvironments of the locality, and elucidate its controversial age. Methods. Repeated re-excavation of key exposures allowed recognition of five main depositional units, differing in thickness from 4 m to 12 m. It also permitted detailed sampling for plant macrofossils and microfossils throughout the succession. Several approaches are integrated to re-assess the taphonomy and preservation of these exceptional plant fossils. Key Results. The deposits are rich in taxonomically diverse miospores and in toto contain at least six well-developed compression floras, together with two beds yielding nodules that enclose well-researched anatomically preserved plants permineralised in calcite. Bulk geochemistry shows that the upper nodules formed by migration of Ca with subordinate Mn and Na. Some phylogenetically important plant fossils recovered in the early 20th century have been traced to their source horizons. Trends in relative proportions of macrofossil and microfossil taxa through the sequence are only moderately congruent, perhaps reflecting the likelihood that microfossils sample the regional rather than the local flora. Conclusions. The Loch Humphrey Burn sequence encompasses a wide range of depositional

  18. Stratigraphy, palaeoenvironments and palaeoecology of the Loch Humphrey Burn lagerstätte and other Mississippian palaeobotanical localities of the Kilpatrick Hills, southwest Scotland.

    PubMed

    Bateman, Richard M; Stevens, Liadan G; Hilton, Jason

    2016-01-01

    Background and Aims. The largely Mississippian strata of the Kilpatrick Hills, located at the western end of the Scottish Midland Valley, enclose several macrofossil floras that together contain ca 21 organ-species of permineralised plants and ca 44 organ-species of compressed plants, here estimated to represent 25 whole-plant species (Glenarbuck = nine, Loch Humphrey Burn Lower = 11, Upper = seven). The most significant locality is the internationally important volcanigenic sequence that is reputedly intercalated within the Clyde Plateau Lava Formation at Loch Humphrey Burn, where ca 30 m of reworked tuffs and other clastic sediments enclose one of the world's most important terrestrial lagerstätten of this period. We here explore the palaeoecology and palaeoenvironments of the locality, and elucidate its controversial age. Methods. Repeated re-excavation of key exposures allowed recognition of five main depositional units, differing in thickness from 4 m to 12 m. It also permitted detailed sampling for plant macrofossils and microfossils throughout the succession. Several approaches are integrated to re-assess the taphonomy and preservation of these exceptional plant fossils. Key Results. The deposits are rich in taxonomically diverse miospores and in toto contain at least six well-developed compression floras, together with two beds yielding nodules that enclose well-researched anatomically preserved plants permineralised in calcite. Bulk geochemistry shows that the upper nodules formed by migration of Ca with subordinate Mn and Na. Some phylogenetically important plant fossils recovered in the early 20th century have been traced to their source horizons. Trends in relative proportions of macrofossil and microfossil taxa through the sequence are only moderately congruent, perhaps reflecting the likelihood that microfossils sample the regional rather than the local flora. Conclusions. The Loch Humphrey Burn sequence encompasses a wide range of depositional

  19. Stratigraphy, palaeoenvironments and palaeoecology of the Loch Humphrey Burn lagerstätte and other Mississippian palaeobotanical localities of the Kilpatrick Hills, southwest Scotland.

    PubMed

    Bateman, Richard M; Stevens, Liadan G; Hilton, Jason

    2016-01-01

    Background and Aims. The largely Mississippian strata of the Kilpatrick Hills, located at the western end of the Scottish Midland Valley, enclose several macrofossil floras that together contain ca 21 organ-species of permineralised plants and ca 44 organ-species of compressed plants, here estimated to represent 25 whole-plant species (Glenarbuck = nine, Loch Humphrey Burn Lower = 11, Upper = seven). The most significant locality is the internationally important volcanigenic sequence that is reputedly intercalated within the Clyde Plateau Lava Formation at Loch Humphrey Burn, where ca 30 m of reworked tuffs and other clastic sediments enclose one of the world's most important terrestrial lagerstätten of this period. We here explore the palaeoecology and palaeoenvironments of the locality, and elucidate its controversial age. Methods. Repeated re-excavation of key exposures allowed recognition of five main depositional units, differing in thickness from 4 m to 12 m. It also permitted detailed sampling for plant macrofossils and microfossils throughout the succession. Several approaches are integrated to re-assess the taphonomy and preservation of these exceptional plant fossils. Key Results. The deposits are rich in taxonomically diverse miospores and in toto contain at least six well-developed compression floras, together with two beds yielding nodules that enclose well-researched anatomically preserved plants permineralised in calcite. Bulk geochemistry shows that the upper nodules formed by migration of Ca with subordinate Mn and Na. Some phylogenetically important plant fossils recovered in the early 20th century have been traced to their source horizons. Trends in relative proportions of macrofossil and microfossil taxa through the sequence are only moderately congruent, perhaps reflecting the likelihood that microfossils sample the regional rather than the local flora. Conclusions. The Loch Humphrey Burn sequence encompasses a wide range of depositional

  20. Carboniferous Psammichnites: Systematic re-evaluation, taphonomy and autecology

    USGS Publications Warehouse

    Mangano, M.G.; Buatois, L.A.; Rindsberg, A.K.

    2002-01-01

    -flat Psammichnites. A first distributional pattern consists of guided meandering specimens preserved in ripple troughs, probably reflecting food-searching of buried organic matter concentrated in troughs. A second is recorded by concentration of Psammichnites on ripple crests and slopes. In some cases, the course is almost straight to slightly sinuous and closely follows topographic highs, suggesting a direct control of bedform morphology on trace pattern. Occurrences of Carboniferous Psammichnites most likely represent an opportunistic strategy in marginal-marine settings. Analysis of Carboniferous Psammichnites indicates the presence of a siphon-like device in the producer and reestablishes the possibility of a molluscan tracemaker.

  1. The stratigraphy and palaeoenvironment of the Bathonian "Great Oolite Group" of Woodeaton Quarry, Oxfordshire.

    NASA Astrophysics Data System (ADS)

    Guthrie, Ronald; Stukins, Stephen; Raub, Tim

    2014-05-01

    Woodeaton Quarry, Oxfordshire, represents the most continuously exposed section of the Upper Bathonian 'Great Oolite Group' in the United Kingdom. Like most of the British Bathonian, it is lacking in reliable ammonite zonation from which to define a chronostratigraphy. The sedimentology of the succession can be broken up into two broad facies types: A clay rich, brackish lagoonal environment with intermixed freshwater-influenced flora and fauna; A marginal marine calcareous succession of an oolitic nature with periodic mud-drape intervals. The marginal marine depositional setting, the completeness of the Upper Bathonian stratigraphy and lack of biostratigraphically important macrofauna has motivated this study into the micropalaeontology of Woodeaton. The primary aims of this study are to use foraminifera and ostracods to reconstruct the palaeoenvironments and to refine the biostratigraphy of the Upper Bathonian. The studied succession commences at the top of the Taynton Limestone Formation, which fines upwards into the clay-rich Rutland Formation. Several species of marine ostracods known from the Mid-Upper Bathonian are recovered from the base of the Rutland Formation, such as Praeschuleridea confossa and Angliaecytherldea calvata, as well as fragments of fish scales and elasmobranch teeth. Freshwater influence is evident further up the Rutland Formation where freshwater charophytes, nested bivalves and ostracods of the genus Bisulcocypris have been found. The progression from the Rutland Formation's marine base into the freshwater influenced clays is clear from the varied micropalaeontological fauna. A return to marine conditions in the overlying White Limestone Formation can be observed through the increasing number of benthic foraminiferal taxa - with Spirillina and Lenticulina the most abundant - compared to the Rutland Formation. Within the Shipton and Ardley Members there are also indicative marine ostracod taxa present (including Acanthocythere

  2. New occurrences of fossilized feathers: systematics and taphonomy of the Santana Formation of the Araripe Basin (Cretaceous), NE, Brazil

    PubMed Central

    Anelli, Luiz Eduardo; Petri, Setembrino; Romero, Guilherme Raffaeli

    2016-01-01

    Here we describe three fossil feathers from the Early Cretaceous Santana Formation of the Araripe Basin, Brazil. Feathers are the most complex multiform vertebrate integuments; they perform different functions, occurring in both avian and non-avian dinosaurs. Despite their rarity, fossil feathers have been found across the world. Most of the Brazilian feather fossil record comes from the Santana Formation. This formation is composed of two members: Crato (lake) and Romualdo (lagoon); both of which are predominantly reduced deposits, precluding bottom dwelling organisms, resulting in exceptional preservation of the fossils. Despite arid and hot conditions during the Cretaceous, life teemed in the adjacency of this paleolake. Feathered non-avian dinosaurs have not yet been described from the Crato Member, even though there are suggestions of their presence in nearby basins. Our description of the three feathers from the Crato laminated limestone reveals that, despite the small sample size, they can be referred to coelurosaurian theropods. Moreover, based on comparisons with extant feather morphotypes they can be identified as one contour feather and two downy feathers. Despite their rareness and low taxonomic potential, fossilized feathers can offer insights about the paleobiology of its owners and the paleoecology of the Araripe Basin. PMID:27441102

  3. New occurrences of fossilized feathers: systematics and taphonomy of the Santana Formation of the Araripe Basin (Cretaceous), NE, Brazil.

    PubMed

    Prado, Gustavo M E M; Anelli, Luiz Eduardo; Petri, Setembrino; Romero, Guilherme Raffaeli

    2016-01-01

    Here we describe three fossil feathers from the Early Cretaceous Santana Formation of the Araripe Basin, Brazil. Feathers are the most complex multiform vertebrate integuments; they perform different functions, occurring in both avian and non-avian dinosaurs. Despite their rarity, fossil feathers have been found across the world. Most of the Brazilian feather fossil record comes from the Santana Formation. This formation is composed of two members: Crato (lake) and Romualdo (lagoon); both of which are predominantly reduced deposits, precluding bottom dwelling organisms, resulting in exceptional preservation of the fossils. Despite arid and hot conditions during the Cretaceous, life teemed in the adjacency of this paleolake. Feathered non-avian dinosaurs have not yet been described from the Crato Member, even though there are suggestions of their presence in nearby basins. Our description of the three feathers from the Crato laminated limestone reveals that, despite the small sample size, they can be referred to coelurosaurian theropods. Moreover, based on comparisons with extant feather morphotypes they can be identified as one contour feather and two downy feathers. Despite their rareness and low taxonomic potential, fossilized feathers can offer insights about the paleobiology of its owners and the paleoecology of the Araripe Basin.

  4. New occurrences of fossilized feathers: systematics and taphonomy of the Santana Formation of the Araripe Basin (Cretaceous), NE, Brazil.

    PubMed

    Prado, Gustavo M E M; Anelli, Luiz Eduardo; Petri, Setembrino; Romero, Guilherme Raffaeli

    2016-01-01

    Here we describe three fossil feathers from the Early Cretaceous Santana Formation of the Araripe Basin, Brazil. Feathers are the most complex multiform vertebrate integuments; they perform different functions, occurring in both avian and non-avian dinosaurs. Despite their rarity, fossil feathers have been found across the world. Most of the Brazilian feather fossil record comes from the Santana Formation. This formation is composed of two members: Crato (lake) and Romualdo (lagoon); both of which are predominantly reduced deposits, precluding bottom dwelling organisms, resulting in exceptional preservation of the fossils. Despite arid and hot conditions during the Cretaceous, life teemed in the adjacency of this paleolake. Feathered non-avian dinosaurs have not yet been described from the Crato Member, even though there are suggestions of their presence in nearby basins. Our description of the three feathers from the Crato laminated limestone reveals that, despite the small sample size, they can be referred to coelurosaurian theropods. Moreover, based on comparisons with extant feather morphotypes they can be identified as one contour feather and two downy feathers. Despite their rareness and low taxonomic potential, fossilized feathers can offer insights about the paleobiology of its owners and the paleoecology of the Araripe Basin. PMID:27441102

  5. The 2.1 Ga Old Francevillian Biota: Biogenicity, Taphonomy and Biodiversity

    PubMed Central

    El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E.; Riboulleau, Armelle; Rollion Bard, Claire; Macchiarelli, Roberto; Ngombi Pemba, Lauriss; Hammarlund, Emma; Meunier, Alain; Moubiya Mouele, Idalina; Benzerara, Karim; Bernard, Sylvain; Boulvais, Philippe; Chaussidon, Marc; Cesari, Christian; Fontaine, Claude; Chi-Fru, Ernest; Garcia Ruiz, Juan Manuel; Gauthier-Lafaye, François; Mazurier, Arnaud; Pierson-Wickmann, Anne Catherine; Rouxel, Olivier; Trentesaux, Alain; Vecoli, Marco; Versteegh, Gerard J. M.; White, Lee; Whitehouse, Martin; Bekker, Andrey

    2014-01-01

    The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations ∼2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rod-shaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life. PMID:24963687

  6. The 2.1 Ga old Francevillian biota: biogenicity, taphonomy and biodiversity.

    PubMed

    El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E; Riboulleau, Armelle; Rollion Bard, Claire; Macchiarelli, Roberto; Ngombi Pemba, Lauriss; Hammarlund, Emma; Meunier, Alain; Moubiya Mouele, Idalina; Benzerara, Karim; Bernard, Sylvain; Boulvais, Philippe; Chaussidon, Marc; Cesari, Christian; Fontaine, Claude; Chi-Fru, Ernest; Garcia Ruiz, Juan Manuel; Gauthier-Lafaye, François; Mazurier, Arnaud; Pierson-Wickmann, Anne Catherine; Rouxel, Olivier; Trentesaux, Alain; Vecoli, Marco; Versteegh, Gerard J M; White, Lee; Whitehouse, Martin; Bekker, Andrey

    2014-01-01

    The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations ∼2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rod-shaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life.

  7. The 2.1 Ga old Francevillian biota: biogenicity, taphonomy and biodiversity.

    PubMed

    El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E; Riboulleau, Armelle; Rollion Bard, Claire; Macchiarelli, Roberto; Ngombi Pemba, Lauriss; Hammarlund, Emma; Meunier, Alain; Moubiya Mouele, Idalina; Benzerara, Karim; Bernard, Sylvain; Boulvais, Philippe; Chaussidon, Marc; Cesari, Christian; Fontaine, Claude; Chi-Fru, Ernest; Garcia Ruiz, Juan Manuel; Gauthier-Lafaye, François; Mazurier, Arnaud; Pierson-Wickmann, Anne Catherine; Rouxel, Olivier; Trentesaux, Alain; Vecoli, Marco; Versteegh, Gerard J M; White, Lee; Whitehouse, Martin; Bekker, Andrey

    2014-01-01

    The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations ∼2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rod-shaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life. PMID:24963687

  8. Palaeoenvironments and palaeoecology of the rudists in the Shuaiba formation (aptian) United Arab Emirates

    NASA Astrophysics Data System (ADS)

    Hamdan, A. R. A.; Alsharhan, A. S.

    The rudists of the Shuaiba Formation (Aptian) of the United Arab Emirates are associated with five principal palaeoenvironmental zones: the shelf lagoon, the back barrier slope, the rudist barrier, the barrier foreslope and the open marine. Six principal lithofacies and five distinguishing biofacies are significant to the recognition and delineation of these palaeoenvironments. The rudist development and colonization were preceeded by the development of algal platform. The thickest and most elevated parts of this platform provided a suitable substrate for the attachment and stabilization of individual rudists. The palaeoecology and the distribution of the Shuaiba rudists are comparable to many Cretaceous rudists reported in North America, Europe and the Middle East. Different Types of rudists lived in different palaeoenvironmental zones. In general, the Monopleuridae, Requienidae, and Caprotinidae are less abundant than the Caprinidae. The Monopluridae and Reqiuinidae,predominate in the shelf lagoon and display a patchy distribution vertically and laterally. The main rudists framework-builders are the Caprinidae. They grow in the rudist barrier zone and may be found transported by gravitational collapse into the back barrier slope and the barrier foreslope zones. The Shuaiba rudists are characterized by low diversity and could survive intermittent exposure and withstand fluctuations in temperature and salinity. However, the influx of argillaceous mud and the deposition of the Nahr Umr shales in Late Aptian killed off the Shuaiba rudists of the region.

  9. Soil and sediments micromorphology: reconstruction of palaeoenvironments, anthropogenic processes, or more recent human impact on ecosystems

    NASA Astrophysics Data System (ADS)

    Gérard, Martine; Trombino, Luca; Stoops, Georges

    2014-05-01

    Soils and sediments registered the environmental changes in time and space, but also display components inherited from human activities, both in archaeological and in modern times. Micromorphological investigations carried out on undisturbed samples of soil and sediments by microscopic and ultramicroscopic techniques, correlated with mineralogy, geochemistry or biology, allow us to interpret the processes behind the formation of regoliths, sediments and anthropogenic deposits, from which a relative chronology, specific environmental conditions and/or extent of human impact may be deduced. The traditional optical microscopy observations, carried on the thin section groundmass and pedofeatures, provide clues on the different processes behind soils and sediments genesis (weathering, supergene, low T hydrothermal, anthropogenic) and their impact on ecosystems or on palaeoenvironments. In more recent times, the improvements in electron microscope imaging technology permit to make detailed observations up to the nanoscale, opening a new domain of observations to micromorphologists, both as regard of the micromass and of the thinner pedofeatures. Moreover, the optimisation of the microgeochemical mapping techniques, with spatially resolved chemical, isotopic or mineralogical analyses, is another powerful tool to gain insight in chemical migration fronts: the limit of the original rock fabric disappearance may be bypassed. In order to illustrate micromorphological researches in natural and man-influenced ecosystems, and to combine researches at different scales, several optical and electronic images of soils and sediments groundmass, associated to their microgeochemical characteristics will be presented, with selected examples taken from the climatic record of paleosols, the impact of hydrothermal alteration on saprolites, the neo-formation of minerals related to weathering process evolution, the protosoil formation in natural and human waste deposits, and the forensic

  10. Taphonomy of fossils from the hominin-bearing deposits at Dikika, Ethiopia.

    PubMed

    Thompson, Jessica C; McPherron, Shannon P; Bobe, René; Reed, Denné; Barr, W Andrew; Wynn, Jonathan G; Marean, Curtis W; Geraads, Denis; Alemseged, Zeresenay

    2015-09-01

    Two fossil specimens from the DIK-55 locality in the Hadar Formation at Dikika, Ethiopia, are contemporaneous with the earliest documented stone tools, and they collectively bear twelve marks interpreted to be characteristic of stone tool butchery damage. An alternative interpretation of the marks has been that they were caused by trampling animals and do not provide evidence of stone tool use or large ungulate exploitation by Australopithecus-grade hominins. Thus, resolving which agents created marks on fossils in deposits from Dikika is an essential step in understanding the ecological and taphonomic contexts of the hominin-bearing deposits in this region and establishing their relevance for investigations of the earliest stone tool use. This paper presents results of microscopic scrutiny of all non-hominin fossils collected from the Hadar Formation at Dikika, including additional fossils from DIK-55, and describes in detail seven assemblages from sieved surface sediment samples. The study is the first taphonomic description of Pliocene fossil assemblages from open-air deposits in Africa that were collected without using only methods that emphasize the selective retention of taxonomically-informative specimens. The sieved assemblages show distinctive differences in faunal representation and taphonomic modifications that suggest they sample a range of depositional environments in the Pliocene Hadar Lake Basin, and have implications for how landscape-based taphonomy can be used to infer past microhabitats. The surface modification data show that no marks on any other fossils resemble in size or shape those on the two specimens from DIK-55 that were interpreted to bear stone tool inflicted damage. A large sample of marks from the sieved collections has characteristics that match modern trampling damage, but these marks are significantly smaller than those on the DIK-55 specimens and have different suites of characteristics. Most are not visible without magnification

  11. Taphonomy of fossils from the hominin-bearing deposits at Dikika, Ethiopia.

    PubMed

    Thompson, Jessica C; McPherron, Shannon P; Bobe, René; Reed, Denné; Barr, W Andrew; Wynn, Jonathan G; Marean, Curtis W; Geraads, Denis; Alemseged, Zeresenay

    2015-09-01

    Two fossil specimens from the DIK-55 locality in the Hadar Formation at Dikika, Ethiopia, are contemporaneous with the earliest documented stone tools, and they collectively bear twelve marks interpreted to be characteristic of stone tool butchery damage. An alternative interpretation of the marks has been that they were caused by trampling animals and do not provide evidence of stone tool use or large ungulate exploitation by Australopithecus-grade hominins. Thus, resolving which agents created marks on fossils in deposits from Dikika is an essential step in understanding the ecological and taphonomic contexts of the hominin-bearing deposits in this region and establishing their relevance for investigations of the earliest stone tool use. This paper presents results of microscopic scrutiny of all non-hominin fossils collected from the Hadar Formation at Dikika, including additional fossils from DIK-55, and describes in detail seven assemblages from sieved surface sediment samples. The study is the first taphonomic description of Pliocene fossil assemblages from open-air deposits in Africa that were collected without using only methods that emphasize the selective retention of taxonomically-informative specimens. The sieved assemblages show distinctive differences in faunal representation and taphonomic modifications that suggest they sample a range of depositional environments in the Pliocene Hadar Lake Basin, and have implications for how landscape-based taphonomy can be used to infer past microhabitats. The surface modification data show that no marks on any other fossils resemble in size or shape those on the two specimens from DIK-55 that were interpreted to bear stone tool inflicted damage. A large sample of marks from the sieved collections has characteristics that match modern trampling damage, but these marks are significantly smaller than those on the DIK-55 specimens and have different suites of characteristics. Most are not visible without magnification

  12. Stacked palimpsests vs. the needle in the haystack: the challenge of reconstructing palaeoenvironments in drylands

    NASA Astrophysics Data System (ADS)

    Fitzsimmons, Kathryn

    2016-04-01

    Drylands, incorporating the semi-arid desert margins vulnerable to desertification and drought, have overseen substantial climatic and environmental changes associated with the Quaternary. However, despite the extent of desert-marginal regions across the world, little is known about the nature and timing of environmental change in the past; likewise the trajectory for future change is uncertain. A major reason for our poor understanding of dryland palaeoenvironmets is likely to be a challenging combination of limited accessibility and the nature of archive preservation in these regions. Here I propose a conceptual framework for reconstructing palaeoenvironments in drylands, based on two respective endmembers in the spectrum of sediment availability. Environments with low sediment availability constitute landscapes containing stratigraphic layers within which successive climatic events may be superimposed, the material traces of which are partially destroyed or reworked. The metaphor of a "stacked palimpsest" is hereby invoked to describe this situation. At the opposite end of the spectrum, sediment-rich environments may result in semi-continuous deposits tens of metres thick and representing a relatively short period of time. This situation represents a challenge to extract the most valuable palaeoenvironmental evidence among the large quantities of sediment, becoming a veritable "needle in the haystack." I will enlarge on these two endmember concepts, using case studies from semi-arid Australia and the Eurasian loess belt to represent the "stacked palimpsest" and "needle in the haystack" metaphors respectively. Australian dryland landscapes are characterised by patchy, poorly preserved and spatially variable sedimentary deposits, and palaeoenvironmental records are consequently preserved over a large spatial and long temporal scale which can be viewed through the framework of the palimpsest model. By contrast, the thick Eurasian loess deposits which border the

  13. Marine Isotope Stage 11: Palaeoclimates, palaeoenvironments and its role as an analogue for the current interglacial

    NASA Astrophysics Data System (ADS)

    Candy, Ian; Schreve, Danielle C.; Sherriff, Jennifer; Tye, Gareth J.

    2014-01-01

    Interglacials of the Quaternary Period are currently the focus of a great deal of attention within the scientific community. This is primarily because they play a vital role in distinguishing between "natural" and "human" climate change in the current interglacial and in understanding how the Holocene would evolve in the absence of anthropogenic greenhouse warming. In this respect, Marine Isotope Stage 11 (MIS 11, ca 410,000 yr BP) is one of the key interglacial stages of the past 450,000 yr. The pattern of insolation variability that occurs during MIS 11 matches that which occurs in the Holocene more closely than in any other warm stage of the past half a million years. In addition there is now an extensive range of evidence for MIS 11 palaeoclimates and palaeoenvironments from marine, ice core, lacustrine and terrestrial sequences. The aim of this paper is to provide a comprehensive review of the current state of our understanding of MIS 11. This is the first paper to provide a detailed review of MIS 11 that incorporates the wide range of marine, ice core, long lacustrine and terrestrial records that have been generated over the last ten years since the last major overview. Crucially, it is the first review of MIS 11 that incorporates a detailed synthesis of the high-resolution terrestrial sequences of western and central Europe. This paper, therefore, provides a holistic integration of a diverse range of proxies and archives to provide a detailed understanding of the expression of MIS 11 in the Earth system. In particular the review focuses on: (1) the climatic background of MIS 11, (2) the robustness of the identification of MIS 11 in a diverse range of sequences, (3) the climatic structure of MIS 11, (4) the magnitude of warmth that occurred in this warm stage, (5) MIS 11 sea level magnitude and variability, (6) the duration of MIS 11, (7) evidence for abrupt climatic events within the interglacial of MIS 11 and (8) precipitation patterns and trends during

  14. The Eagle Ford Shale, Texas: an initial insight into Late Cretaceous organic-rich mudrock palaeoenvironments

    NASA Astrophysics Data System (ADS)

    Forshaw, Joline; Jarvis, Ian; Trabucho-Alexandre, João; Tocher, Bruce; Pearce, Martin

    2014-05-01

    , making further study essential before these resources can be fully developed. Therefore, a thorough understanding of the subsurface sediments within a coherent stratigraphic framework is required before exploitation can be optimimised. Here, we present initial palynological data (dinoflagellate cyst abundance), in conjunction with geochemistry, from material obtained from the Maverick Basin in the southwestern area of Eagle Ford Shale deposition. Results are presented as part of a wider study of the Eagle Ford Shale, utilising both core and outcrop material, that is using dinoflagellate cysts and chemostratigraphy to develop an improved stratigraphic framework and to reconstruct depositional palaeoenvironments in the basin.

  15. Environmental occurrences

    SciTech Connect

    Black, D.G.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the onsite and offsite releases of radioactive and regulated materials. The specific agencies notified of the releases depended on the type, amount, and location of the individual occurrences. The more significant of these off-normal environmental occurrences are summarized in this section.

  16. Nd and Sr isotope compositions in modern and fossil bones - Proxies for vertebrate provenance and taphonomy

    NASA Astrophysics Data System (ADS)

    Tütken, Thomas; Vennemann, Torsten W.; Pfretzschner, Hans-U.

    2011-10-01

    Rare earth elements (REE), while not essential for the physiologic functions of animals, are ingested and incorporated in ppb concentrations in bones and teeth. Nd isotope compositions of modern bones of animals from isotopically distinct habitats demonstrate that the 143Nd/ 144Nd of the apatite can be used as a fingerprint for bedrock geology or ambient water mass. This potentially allows the provenance and migration of extant vertebrates to be traced, similar to the use of Sr isotopes. Although REE may be enriched by up to 5 orders of magnitude during diagenesis and recrystallization of bone apatite, in vivo143Nd/ 144Nd may be preserved in the inner cortex of fossil bones or enamel. However, tracking the provenance of ancient or extinct vertebrates is possible only for well-preserved archeological and paleontological skeletal remains with in vivo-like Nd contents at the ppb-level. Intra-bone and -tooth REE analysis can be used to screen for appropriate areas. Large intra-bone Nd concentration gradients of 10 1-10 3 are often measured. Nd concentrations in the inner bone cortex increase over timescales of millions of years, while bone rims may be enriched over millenial timescales. Nevertheless, ɛ Nd values are often similar within one ɛ Nd unit within a single bone. Larger intra-bone differences in specimens may either reflect a partial preservation of in vivo values or changing ɛ Nd values of the diagenetic fluid during fossilization. However, most fossil specimens and the outer rims of bones will record taphonomic 143Nd/ 144Nd incorporated post mortem during diagenesis. Unlike REE patterns, 143Nd/ 144Nd are not biased by fractionation processes during REE-uptake into the apatite crystal lattice, hence the ɛ Nd value is an important tracer for taphonomy and reworking. Bones and teeth from autochthonous fossil assemblages have small variations of ±1 ɛ Nd unit only. In contrast, fossil bones and teeth from over 20 different marine and terrestrial fossil

  17. The Tendaguru formation of southeastern Tanzania, East Africa: An alternating Late Jurassic to Early Cretaceous palaeoenvironment of exceptional status

    NASA Astrophysics Data System (ADS)

    Sames, B.

    2009-04-01

    Dinosaur remains have inspired considerable scientific interest in the Tendaguru formation of southeastern Tanzania during the 20th century; however, this formation is exceptional in many other respects. The Late Jurassic to Early Cretaceous deposits of the Tendaguru formation in the southwestern Tethys are unique because they represent a marginal marine palaeoenvironment with nonmarine faunal and floral content. It is a threefold succession of marginal marine to terrestrial, carbonate-siliciclastic sediments with cyclic character, consisting of three transgressive-regressive cycles. Revisitation of the type locality (the Tendaguru, a hill approximately 60km northwest of the town of Lindi) by a German-Tanzanian expedition in summer 2000 (Heinrich et al., 2001) resulted in a new standard section (hitherto unpublished, the informal terminology is indicated by the use of lower case in Tendaguru formation), a refined environmental model (Aberhan et al., 2002) and many new insights towards its geology (with evidence of event-sedimentation, Bussert and Aberhan, 2004), biostratigraphy and a better understanding of the Tendaguru palaeo-ecosystems and the palaeoclimate. Within the scope of the designation of a new standard section at the type locality, calcareous microfossils (ostracods, charophytes) have been described to supplement the ongoing discussion about the age and palaeoecology of the Tendaguru formation (Sames, 2008). Although only a few unevenly distributed layers across the section produced calcareous microfossils, the results are very promising. A total of 40 ostracode and 2 charophyte taxa could be distinguished. The non-marine part of the ostracod fauna provides an important contribution to the documentation of Purbeck/Wealden-type nonmarine palaeoenvironments and its microfaunas and -floras previously unknown from East Africa. The marine faunal part belongs to a relatively endemic southern (Gondwana) fauna. Together with other fossil groups, the

  18. Experimental taphonomy of giant sulphur bacteria: implications for the interpretation of the embryo-like Ediacaran Doushantuo fossils.

    PubMed

    Cunningham, J A; Thomas, C-W; Bengtson, S; Marone, F; Stampanoni, M; Turner, F R; Bailey, J V; Raff, R A; Raff, E C; Donoghue, P C J

    2012-05-01

    The Ediacaran Doushantuo biota has yielded fossils interpreted as eukaryotic organisms, either animal embryos or eukaryotes basal or distantly related to Metazoa. However, the fossils have been interpreted alternatively as giant sulphur bacteria similar to the extant Thiomargarita. To test this hypothesis, living and decayed Thiomargarita were compared with Doushantuo fossils and experimental taphonomic pathways were compared with modern embryos. In the fossils, as in eukaryotic cells, subcellular structures are distributed throughout cell volume; in Thiomargarita, a central vacuole encompasses approximately 98 per cent cell volume. Key features of the fossils, including putative lipid vesicles and nuclei, complex envelope ornament, and ornate outer vesicles are incompatible with living and decay morphologies observed in Thiomargarita. Microbial taphonomy of Thiomargarita also differed from that of embryos. Embryo tissues can be consumed and replaced by bacteria, forming a replica composed of a three-dimensional biofilm, a stable fabric for potential fossilization. Vacuolated Thiomargarita cells collapse easily and do not provide an internal substrate for bacteria. The findings do not support the hypothesis that giant sulphur bacteria are an appropriate interpretative model for the embryo-like Doushantuo fossils. However, sulphur bacteria may have mediated fossil mineralization and may provide a potential bacterial analogue for other macroscopic Precambrian remains.

  19. Experimental taphonomy of giant sulphur bacteria: implications for the interpretation of the embryo-like Ediacaran Doushantuo fossils.

    PubMed

    Cunningham, J A; Thomas, C-W; Bengtson, S; Marone, F; Stampanoni, M; Turner, F R; Bailey, J V; Raff, R A; Raff, E C; Donoghue, P C J

    2012-05-01

    The Ediacaran Doushantuo biota has yielded fossils interpreted as eukaryotic organisms, either animal embryos or eukaryotes basal or distantly related to Metazoa. However, the fossils have been interpreted alternatively as giant sulphur bacteria similar to the extant Thiomargarita. To test this hypothesis, living and decayed Thiomargarita were compared with Doushantuo fossils and experimental taphonomic pathways were compared with modern embryos. In the fossils, as in eukaryotic cells, subcellular structures are distributed throughout cell volume; in Thiomargarita, a central vacuole encompasses approximately 98 per cent cell volume. Key features of the fossils, including putative lipid vesicles and nuclei, complex envelope ornament, and ornate outer vesicles are incompatible with living and decay morphologies observed in Thiomargarita. Microbial taphonomy of Thiomargarita also differed from that of embryos. Embryo tissues can be consumed and replaced by bacteria, forming a replica composed of a three-dimensional biofilm, a stable fabric for potential fossilization. Vacuolated Thiomargarita cells collapse easily and do not provide an internal substrate for bacteria. The findings do not support the hypothesis that giant sulphur bacteria are an appropriate interpretative model for the embryo-like Doushantuo fossils. However, sulphur bacteria may have mediated fossil mineralization and may provide a potential bacterial analogue for other macroscopic Precambrian remains. PMID:22158954

  20. Taphonomy of deciduous leaves and changes in the d13C signal after deposition in fresh water settings

    NASA Astrophysics Data System (ADS)

    Reimann, Simon; Roth-Nebelsick, Anita; Nebelsick, James; Grein, Michaela

    2016-04-01

    Carbon isotopic signals from fossil plant material are an important source of information for palaeoecology and palaeoclimatology. Usually, the 13C isotope is depleted in plant material, compared to the atmospheric 13C content, because 13C is discriminated against 12C during the process of photosynthesis. The degree of 13C discrimination depends on the photosynthetic pathway (C3, C4 and CAM) and is substantially affected by environmental factors (for example, water stress). Various plant material components, however, differ also with respect to their 13C content. It is generally assumed that the d13C signal found in fossil plants reflects that of the living plant to a sufficient degree. Obtaining information on possible alterations during the taphonomic process is, however, desirable. In this study, changes in d13C of deciduous leaves are monitored, from the living leaf still attached to the tree to leaves deposited in fresh water setting for one or more years, thus focusing on early stages of taphonomy. The considered taxa are species from Quercus (oak) and Fagus (beech). Deposited leaves from three fresh water environments in Southwestern Germany were studied: active stream in a forest, still water pond in a forest, and a waterlogged moor environment. Additionally to the isotope measurements, the degree of leaf tissue degradation and colonization with degrading organisms were observed with Scanning Electron Microscopy.

  1. Palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin, northern South China Sea.

    PubMed

    Li, Wenhao; Zhang, Zhihuan; Wang, Weiming; Lu, Shuangfang; Li, Youchuan; Fu, Ning

    2014-01-01

    The main factors of the developmental environment of marine source rocks in continental margin basins have their specificality. This realization, in return, has led to the recognition that the developmental environment and pattern of marine source rocks, especially for the source rocks in continental margin basins, are still controversial or poorly understood. Through the analysis of the trace elements and maceral data, the developmental environment of Miocene marine source rocks in the Qiongdongnan Basin is reconstructed, and the developmental patterns of the Miocene marine source rocks are established. This paper attempts to reveal the hydrocarbon potential of the Miocene marine source rocks in different environment and speculate the quality of source rocks in bathyal region of the continental slope without exploratory well. Our results highlight the palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin of the northern South China Sea and speculate the hydrocarbon potential of the source rocks in the bathyal region. This study provides a window for better understanding the main factors influencing the marine source rocks in the continental margin basins, including productivity, preservation conditions, and the input of terrestrial organic matter.

  2. Palaeoenvironment and Its Control on the Formation of Miocene Marine Source Rocks in the Qiongdongnan Basin, Northern South China Sea

    PubMed Central

    Li, Wenhao; Zhang, Zhihuan; Wang, Weiming; Lu, Shuangfang; Li, Youchuan; Fu, Ning

    2014-01-01

    The main factors of the developmental environment of marine source rocks in continental margin basins have their specificality. This realization, in return, has led to the recognition that the developmental environment and pattern of marine source rocks, especially for the source rocks in continental margin basins, are still controversial or poorly understood. Through the analysis of the trace elements and maceral data, the developmental environment of Miocene marine source rocks in the Qiongdongnan Basin is reconstructed, and the developmental patterns of the Miocene marine source rocks are established. This paper attempts to reveal the hydrocarbon potential of the Miocene marine source rocks in different environment and speculate the quality of source rocks in bathyal region of the continental slope without exploratory well. Our results highlight the palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin of the northern South China Sea and speculate the hydrocarbon potential of the source rocks in the bathyal region. This study provides a window for better understanding the main factors influencing the marine source rocks in the continental margin basins, including productivity, preservation conditions, and the input of terrestrial organic matter. PMID:25401132

  3. Palynological age and palaeoenvironment of deposition of Mid-Cenozoic sediments around Umuahia, Niger delta basin, southeastern Nigeria

    NASA Astrophysics Data System (ADS)

    Ikegwuonu, Okechukwu N.; Umeji, Obianuji P.

    2016-05-01

    The sediments of Oligocene - Early Miocene Ogwashi Formation of the Niger Delta Basin exposed in the kaolinite quarry by Oyivo stream in Umuahia comprise four lithological units which from base to top are (a) white to grey mudstone over 5.0 m thick; (b) lignite 1.0 m; (c) carbonaceous grey to dark shale 3.0 m; and (d) medium to coarse grained argillaceous sandstone 8.5 m. Samples from lignite and carbonaceous shale yielded rich palynomorph assemblages. Argillaceous sandstone and mudstone were barren. Lignite recorded more spores and less pollen while carbonaceous shale had more pollen and less spores. Index sporomorphs include Verrucatosporites usmensis, Magnastriatites howardii, Psilatricolporites crassus, Echiperiporites icacinoides, Echiperiporites minor, Retibrevitricolporites protrudens, Retibrevitricolpo-rites obodoensis, Retibrevitricolporites ibadanensis, Chenopodipollis dispersus and Retitricolporites irregularis representing Oligocene - Early Miocene Verrucatosporites usmensis/Magnastriatites howardii pantropical palynozones. Palaeoenvironmental indicators include Monoporites annulatus, grass pollen commonly found in open vegetation of savannah or reed swamps within the rain forests; Psilastephanocolporites laevigatus, the tropical lowland evergreen tree; Proxapertites operculatus, Longapertites marginatus and Psilatricolporites crassus the palms of brackish water swamp, along with Schizosporis parvus (Spirogyra) a fresh-water green alga. The sporomorphs indicate palaeoenvironments ranging from fresh water upper to brackish water lower deltaic plain within the tropical rainforest.

  4. PREFACE: 1st METECH workshop - From deep-sea to coastal zones: Methods and Techniques for studying Palaeoenvironments

    NASA Astrophysics Data System (ADS)

    Veiga-Pires, C.; St-Onge, G.

    2008-10-01

    Reconstructing past climate and past ocean circulation demands the highest possible precision and accuracy which urges the scientific community to look at different sediment records such as the ones from coastal zones to deep-sea with a more complete set of technical and methodological tools. However, the information given by each tool varies in precision, accuracy and in significance according to their environmental settings. It is therefore essential to compare tools. With that in mind, and as part of the International year of Planet Earth, a workshop entitled `From deep-sea to coastal zones: Methods and Techniques for studying palaeoenvironments' took place in Faro (Portugal), from 25-29 February 2008 in order to: present several methods and techniques that can be used for studying sediments from deep-sea to coastal zones, namely for reconstructing palaeoenvironments in order to document past climatic changes and short to long-term environmental processes; allow cross experience between different fields and specialties, either from deep-sea to coastal zones or from micropaleontology to geochemistry; give the opportunity to students from different universities and countries to attend the workshop; publish a special volume on the presented methods and techniques during the workshop. The workshop was organized in four non-parallel sessions dealing with the use of micropaleontology, isotopes, biogeochemistry and sedimentology, as tools for palaeoenvironmental studies. The present IOP Conference Series: Earth and Environmental Science proceedings reflect this organization and papers are published in each theme. The papers are either short reviews or case studies and are highlighted below. The remains of microorganisms found in sediments are the main proxies used in micropaleontological studies. However, the link between fossilized remains and their living origin is not easy to reconstruct only based on the geologic/sedimentary record. Accordingly, Barbosa presents a

  5. Reconstructing the palaeoenvironments of the early Pleistocene mammal faunas from the pollen preserved on fossil bones

    NASA Astrophysics Data System (ADS)

    Ravazzi, Cesare; Pini, Roberta; Breda, Marzia

    2009-12-01

    We carried out a systematic investigation on the pollen content of sediment adhering to skeletal elements of large mammals which originate from the long lacustrine record of Leffe (Early Pleistocene of the Italian Alps). Three local faunas were discovered during mining activities along the intermediate part (spanning from 1.5 to 0.95 Ma) of the basin succession. The excellent pollen preservation allowed testing the reproducibility of the pollen signal from single skeletons. A clear palaeoenvironmental patterning, consistent with the ecological preferences of the considered mammal species, emerged from the canonical correspondence analysis of pollen types diagnostic for vegetation communities. Edaphic factors related to seasonal river activity changes and to the development of swamp forests in the riverbanks are significantly associated to the occurrences of Hippopotamus cf. antiquus, whereas finds of Mammuthus meridionalis belong to fully forested landscapes dominated by conifer or mixed forests of oceanic, warm to cool-temperate climate. Rhinoceros habitats include variable forest cover under different climate states. Distinct cool-temperate, partially open vegetation could be recognized for large deer included Cervalces cf carnutorum. A palynostratigraphic correlation between individual spectra and a reference palynostratigraphic record allowed assignment of many fossil remains to a precise stratigraphic position. This procedure also shown that the Leffe local faunas include specimens accumulated under different environmental and climate states, as a consequence of high-frequency climate changes characterizing the Late Villafranchian Early Pleistocene.

  6. The latest succession of dinosaur tracksites in Europe: Hadrosaur ichnology, track production and palaeoenvironments.

    PubMed

    Vila, Bernat; Oms, Oriol; Fondevilla, Víctor; Gaete, Rodrigo; Galobart, Angel; Riera, Violeta; Canudo, José Ignacio

    2013-01-01

    A comprehensive review and study of the rich dinosaur track record of the Tremp Formation in the southern Pyrenees of Spain (Southwestern Europe) shows a unique succession of footprint localities prior to the end-Cretaceous mass extinction event. A description of some 30 new tracksites and data on sedimentary environments, track occurrence and preservation, ichnology and chronostratigraphy are provided. These new track localities represent various facies types within a diverse set of fluvial environments. The footprint discoveries mostly represent hadrosaurian and, less abundantly, to sauropod dinosaurs. The hadrosaur tracks are significantly smaller in size than, but morphologically similar to, those of North America and Asia and are attributable to the ichnogenus Hadrosauropodus. The track succession, with more than 40 distinct track levels, indicates that hadrosaur footprints in the Ibero-Armorican region occur predominantly in the late Maaastrichtian (at least above the early Maastrichtian-late Maastrichtian boundary). The highest abundance is found noticeably found in the late Maastrichtian, with tracks occurring in the C29r magnetochron, within about the latest 300,000 years of the Cretaceous.

  7. The Latest Succession of Dinosaur Tracksites in Europe: Hadrosaur Ichnology, Track Production and Palaeoenvironments

    PubMed Central

    Vila, Bernat; Oms, Oriol; Fondevilla, Víctor; Gaete, Rodrigo; Galobart, Àngel; Riera, Violeta; Canudo, José Ignacio

    2013-01-01

    A comprehensive review and study of the rich dinosaur track record of the Tremp Formation in the southern Pyrenees of Spain (Southwestern Europe) shows a unique succession of footprint localities prior to the end-Cretaceous mass extinction event. A description of some 30 new tracksites and data on sedimentary environments, track occurrence and preservation, ichnology and chronostratigraphy are provided. These new track localities represent various facies types within a diverse set of fluvial environments. The footprint discoveries mostly represent hadrosaurian and, less abundantly, to sauropod dinosaurs. The hadrosaur tracks are significantly smaller in size than, but morphologically similar to, those of North America and Asia and are attributable to the ichnogenus Hadrosauropodus. The track succession, with more than 40 distinct track levels, indicates that hadrosaur footprints in the Ibero-Armorican region occur predominantly in the late Maaastrichtian (at least above the early Maastrichtian–late Maastrichtian boundary). The highest abundance is found noticeably found in the late Maastrichtian, with tracks occurring in the C29r magnetochron, within about the latest 300,000 years of the Cretaceous. PMID:24019873

  8. Insights into Pleistocene palaeoenvironments and biostratigraphy in southern Buenos Aires province (Argentina) from continental deposits

    NASA Astrophysics Data System (ADS)

    Beilinson, E.; Gasparini, G. M.; Soibelzon, L. H.; Soibelzon, E.

    2015-07-01

    The coastal cliffs of the Buenos Aires province (Argentina) have been the subject of intense paleontological studies since the XIX century. Therefore, many of the type localities in which is based the late Cenozoic Pampean biostratigraphic/chronostratigraphic scheme are located in this area. In this context, the sedimentites that crop out near the mouth of the Chocorí Creek contain a set of palaeontological sites that, because of their richness and well-preserved fossil content, hold high national and international importance. The aims of the present contribution are: 1) to make a stratigraphic and sedimentological characterization of the study area; 2) to list the fauna outcropped at these palaeontological sites and establish a biostratigraphic framework; 3) to elaborate a palaeoenvironmental model for the area. The study interval was informally subdivided into a lower, middle and upper interval. Interpretation was based on the presence of a number of key features such as architectural elements; channel:overbank ratio and palaeosol occurrence. The first two intervals were interpreted as continental deposits of a fluvio-alluvial nature and are the focus of this paper. The upper interval was related to foreshore marine deposits and will be studied in a future contribution. The lower interval is characterized mainly by overbank architectural elements in which calcisols and argillic protosols were identified. Channel-fill deposits are isolated and surrounded by fine-grained overbank successions and sedimentary structures are suggestive of mixed-load transport. The contact between the lower and middle intervals is an irregular, highly erosive surface characterized by a significant vertical change in the facies. This surface defines the base of multistorey sandbodies which's internal arrangement alongside with the low participation of overbank deposits suggests deposition by a braided fluvial system. Palaeosols and vertebrate fossils were used as palaeoclimatic

  9. The First Ant-Termite Syninclusion in Amber with CT-Scan Analysis of Taphonomy

    PubMed Central

    Coty, David; Aria, Cédric; Garrouste, Romain; Wils, Patricia; Legendre, Frédéric; Nel, André

    2014-01-01

    We describe here a co-occurrence (i.e. a syninclusion) of ants and termites in a piece of Mexican amber (Totolapa deposit, Chiapas), whose importance is two-fold. First, this finding suggests at least a middle Miocene antiquity for the modern, though poorly documented, relationship between Azteca ants and Nasutitermes termites. Second, the presence of a Neivamyrmex army ant documents an in situ raiding behaviour of the same age and within the same community, confirmed by the fact that the army ant is holding one of the termite worker between its mandibles and by the presence of a termite with bitten abdomen. In addition, we present how CT-scan imaging can be an efficient tool to describe the topology of resin flows within amber pieces, and to point out the different states of preservation of the embedded insects. This can help achieving a better understanding of taphonomical processes, and tests ethological and ecological hypotheses in such complex syninclusions. PMID:25140873

  10. Mid-Pleistocene palaeolakes of the Western Desert of Egypt: Palaeoclimate records, palaeoenvironments, and implications

    NASA Astrophysics Data System (ADS)

    Kieniewicz, J. M.; Smith, J. R.

    2006-12-01

    The occurrence of lacustrine carbonates in the Western Desert of Egypt forms one line of evidence for pluvial phases in the Eastern Sahara during the Pleistocene. The study of palaeolake sediments at Kharga and Dakhleh Oasis has yielded information on the hydrology and water balance necessary to maintain the bodies of water during pluvial climates. At Wadi Midauwara in the southeast of Kharga Oasis, ~8 m of authigenic calcite silts are found in association with extensive tufa deposits representing at least three separate pluvial phases during the Pleistocene. The silts are probably coeval with MIS 5e, as they are overlain by a tufa unit dated to 126±4 ka and as they are very friable, could not have survived a prolonged period of aridity. Stable isotope and minor element analyses of the silts and the gastropod shells found within them are not consistent with a highly evaporative environment—in fact they suggest that the lake was probably hydrologically open, and remained perennially fresh. The silt geochemistry has also provided insight on the relationships between evaporation and water residence time in local limestone aquifers. Unlike the lake at Wadi Midauwara which probably received its water primarily from spring discharge, the Dakhleh palaeolake was partly supported by Nubian aquifer groundwater discharging at a higher rate than today. Despite this, the lake likely received considerable input from locally recharged water since Nubian aquifer is undersaturated with respect to calcite in Dakhleh Oasis, and the high carbonate content of the marls demands the input of carbonate derived from the nearby Libyan Plateau. Furthermore, the presence of tufa deposits along the escarpment suggests that water derived from the plateau likely contributed to the water budget of the lake. The lake sediments occur as erosional remnants on the southern margins of the Dakhleh basin to the south of the Libyan Plateau, and primarily represent shallow lacustrine facies. δ 18O

  11. Late Miocene fossils from shallow marine sediments in Brunei Darussalam: systematics, palaeoenvironment and ecology.

    NASA Astrophysics Data System (ADS)

    Roslim, Amajida; Briguglio, Antonino; Kocsis, László; Ćorić, Stjepan; Razak, Hazirah

    2016-04-01

    The geology of Brunei Darussalam is fascinating but difficult to approach: rainforests and heavy precipitation tend to erode and smoothen the landscape limiting rocks exposure, whereas abundant constructions sites and active quarries allow the creation of short time available outcrop, which have to be immediately sampled. The stratigraphy of Brunei Darussalam comprises mainly Neogene sediments deposited in a wave to tide dominated shallow marine environment in a pure siliciclastic system. Thick and heavily bioturbated sandstone layers alternate to claystone beds which occasionally yield an extraordinary abundance and diversity of fossils. The sandstones, when not bioturbated, are commonly characterized by a large variety of sedimentary structures (e.g., ripple marks, planar laminations and cross beddings). In this study, we investigate the sediments and the fossil assemblages to record the palaeoenvironmental evolution of the shallow marine environment during the late Miocene, in terms of sea level change, chemostratigraphy and sedimentation rate. The study area is one of the best in terms of accessibility, extension, abundance and preservation of fossils; it is located in the region -'Bukit Ambug' (Ambug Hill), Tutong District. The fossils fauna collected encompasses mollusks, decapods, otoliths, shark and ray teeth, amber, foraminifera and coccolithophorids. In this investigation, sediment samples were taken along a section which measures 62.5 meters. A thick clay layer of 9 meters was sampled each 30 cm to investigate microfossils occurrences. Each sample was treated in peroxide and then sieved trough 63 μm, 150μm, 250μm, 450μm, 600μm, 1mm and 2mm sieves. Results point on the changes in biodiversity of foraminifera along the different horizons collected reflecting sea level changes and sediment production. The most abundant taxa identified are Pseoudorotalia schroeteriana, Ampistegina lessonii, Elphidium advenum, Quinqueloculina sp., Bolivina sp

  12. Taphonomy of a thick Terebratula bioherm from the Pliocene of southeastern Spain

    NASA Astrophysics Data System (ADS)

    García-Ramos, Diego A.

    2015-04-01

    many of these shells were drilled by gastropods. Co-occurrence of altered fragments and articulated shells of Terebratula suggests that shells of this brachiopod underwent different taphonomic pathways, implying that different generations of Terebratula were able to thrive in this habitat over a period of time long enough to produce the range of taphonomic signatures encountered. Taphonomic traits point to a within-habitat time-averaged fossil assemblage, namely: 1) sediment starvation (on account of a dense bioturbation and abrasion, bioerosion, encrustation, and fragmentation of shells accumulated in clusters). 2) fossils with distinctly different taphonomic signatures corresponding to the biostratinomic phase. 3) lithologically homogeneous matrix. 4) a functional agreement between fauna and matrix. The occurrence of fixossesile organisms such as Pododesmus, Ancistrocrania and the abundance of Podichnus (which suggests that Terebratula attached to dead and alive conspecific shells) and other bioerosive traces, point out a shift from a soft/firmground to a shelly-ground propitious for the colonization by diverse epilithic animals. These features are consistent with autigenic and allogenic taphonomic feedback. Allogenic mode is suggested by reworking and winnowing by storm currents. The influence of storms is also recorded by unaltered, hollow shells of Terebratula (rapid burial), the stacked biofabrics, and the infilling of pod-like pits by shell fragments.

  13. An integrated approach to taphonomy and faunal change in the Shungura formation (Ethiopia) and its implication for hominid evolution.

    PubMed

    Alemseged, Zeresenay

    2003-04-01

    Environmental and faunal changes through time have been recorded for many African Plio-Pleistocene sites. Fossil evidence suggests that there is a continuous, if not uniform, transformation of the fauna and flora from the Pliocene through the end of Pleistocene. However, discerning major biotic turnovers and linking them to global and regional climatic changes have been complicated by many factors, notably taphonomy and discontinuity of the fossil evidence, notwithstanding the considerable work of some researchers (e.g., Vrba, E.S., 1988. Late Pliocene climatic events and hominid evolution, in: Grine, F. (Ed.), Evolutionary History of the "Robust" Australopithecines. De Gruyter, New York, pp. 405-426, Vrba, E.S., 1995. The fossil record of African (Mammalia, Bovidae) in relation to human evolution and paleoclimate, in: Vrba, E.S., Denton, G.H., Partridge, T.C., Burkle, L.H. (Eds.), Paleoclimate and Evolution, with Emphasis on Human Origins. Yale University Press, New Haven, pp. 385-424). A sample of over 22,000 fossils collected by the French Omo Expedition, from the Shungura Formation of Ethiopia, was analyzed using an integrated approach to investigate taphonomic and faunal change patterns. The following results are obtained: (1) Univariate and multivariate studies support continuous faunal change from Member A through Member G of the Shungura sequence; (2) Correspondence analysis (CA) on extant bovids in African game parks shows that bovid tribes and genera are generally characterized by habitat specificity; (3) Taphonomic studies demonstrate that the relative abundance of different skeletal elements varies according to depositional environment; (4) CA on 73 localities of the Shungura Formation and 19 mammalian taxa points to a major faunal change around the base of Member G dated to ca. 2.3 Ma. This transformation is characterized by a change to open and edaphic grassland as a dominant type of environment; (5) This major faunal change correlates in time with

  14. An integrated approach to taphonomy and faunal change in the Shungura formation (Ethiopia) and its implication for hominid evolution.

    PubMed

    Alemseged, Zeresenay

    2003-04-01

    Environmental and faunal changes through time have been recorded for many African Plio-Pleistocene sites. Fossil evidence suggests that there is a continuous, if not uniform, transformation of the fauna and flora from the Pliocene through the end of Pleistocene. However, discerning major biotic turnovers and linking them to global and regional climatic changes have been complicated by many factors, notably taphonomy and discontinuity of the fossil evidence, notwithstanding the considerable work of some researchers (e.g., Vrba, E.S., 1988. Late Pliocene climatic events and hominid evolution, in: Grine, F. (Ed.), Evolutionary History of the "Robust" Australopithecines. De Gruyter, New York, pp. 405-426, Vrba, E.S., 1995. The fossil record of African (Mammalia, Bovidae) in relation to human evolution and paleoclimate, in: Vrba, E.S., Denton, G.H., Partridge, T.C., Burkle, L.H. (Eds.), Paleoclimate and Evolution, with Emphasis on Human Origins. Yale University Press, New Haven, pp. 385-424). A sample of over 22,000 fossils collected by the French Omo Expedition, from the Shungura Formation of Ethiopia, was analyzed using an integrated approach to investigate taphonomic and faunal change patterns. The following results are obtained: (1) Univariate and multivariate studies support continuous faunal change from Member A through Member G of the Shungura sequence; (2) Correspondence analysis (CA) on extant bovids in African game parks shows that bovid tribes and genera are generally characterized by habitat specificity; (3) Taphonomic studies demonstrate that the relative abundance of different skeletal elements varies according to depositional environment; (4) CA on 73 localities of the Shungura Formation and 19 mammalian taxa points to a major faunal change around the base of Member G dated to ca. 2.3 Ma. This transformation is characterized by a change to open and edaphic grassland as a dominant type of environment; (5) This major faunal change correlates in time with

  15. Systematics, phylogeny, and taphonomy of ghost shrimps (Decapoda): a perspective from the fossil record

    PubMed Central

    Klompmaker, Adiël A.

    2016-01-01

    Ghost shrimps of Callianassidae and Ctenochelidae are soft-bodied, usually heterochelous decapods representing major bioturbators of muddy and sandy (sub)marine substrates. Ghost shrimps have a robust fossil record spanning from the Early Cretaceous (~ 133 Ma) to the Holocene and their remains are present in most assemblages of Cenozoic decapod crustaceans. Their taxonomic interpretation is in flux, mainly because the generic assignment is hindered by their insufficient preservation and disagreement in the biological classification. Furthermore, numerous taxa are incorrectly classified within the catch-all taxon Callianassa. To show the historical patterns in describing fossil ghost shrimps and to evaluate taphonomic aspects influencing the attribution of ghost shrimp remains to higher level taxa, a database of all fossil species treated at some time as belonging to the group has been compiled: 250 / 274 species are considered valid ghost shrimp taxa herein. More than half of these taxa (160 species, 58.4%) are known only from distal cheliped elements, i.e., dactylus and / or propodus, due to the more calcified cuticle locally. Rarely, ghost shrimps are preserved in situ in burrows or in direct association with them, and several previously unpublished occurrences are reported herein. For generic assignment, fossil material should be compared to living species because many of them have modern relatives. Heterochely, intraspecific variation, ontogenetic changes and sexual dimorphism are all factors that have to be taken into account when working with fossil ghost shrimps. Distal elements are usually more variable than proximal ones. Preliminary results suggest that the ghost shrimp clade emerged not before the Hauterivian (~ 133 Ma). The divergence of Ctenochelidae and Paracalliacinae is estimated to occur within the interval of Hauterivian to Albian (133–100 Ma). Callichirinae and Eucalliacinae likely diverged later during the Late Cretaceous (100–66 Ma

  16. The hydrocarbon potential, thermal maturity, sequence stratigraphic setting and depositional palaeoenvironment of carbonaceous shale and lignite successions of Panandhro, northwestern Kutch Basin, Gujarat, Western India

    NASA Astrophysics Data System (ADS)

    Sahay, Vinay

    2011-03-01

    The objective of the present paper is to provide geochemical and palynological data to characterize lignites and carbonaceous shales from Panandhro, northwestern Kutch Basin, Gujarat, Western India, in terms of their hydrocarbon potential, thermal maturity, sequence stratigraphic settings and depositional palaeoenvironment. The samples, collected in Panandhro lignite mine, belong to Naredi Formation of Late Paleocene-Early Eocene age. The geochemical results are based on proximate analysis, ultimate analysis, X-ray diffraction and Rock-Eval py-rolysis analyses, whereas palynological data include palynofossil composition and thermal alteration index (TAI). The TOC, hydrogen index (HI), cracked hydrocarbon (S2), bitumen index (BI), quality index (QI), and the total genetic potential (S1+S2) values indicate that the studied lignites and carbonaceous shales have good source rock potential. The organic matter is predominantly of type II and type II/III kerogen, which has potential to generate oil as well as gas. Thermal maturity determined from thermal alteration index (TAI), Tmax and production index (PI) indicates that the organic matter is immature, and in the diagenesis stage of organic matter transformation. The deposition of the studied carbonaceous shales and lignites took place in palaeoenvironments varying from brackish mangrove to freshwater swamp. This study indicates that the proportion of ferns, palms, volatile matter content, S/C, H/C ratios, as well as the presence of siderite and quartz can be used as an indicator of accommodation trends in the coal depositional system. The Panandhro carbonaceous shales and lignites were deposited during the lowstand systems tract with many cycles of small magnitude trangressive-regressive phases. Thus, the geochemistry and ecological palynology are useful not only for the investigation of coal quality and origin, but also to infer accommodation space settings of the mire. This can be gainfully utilized in the coal

  17. The hydrocarbon potential, thermal maturity, sequence stratigraphic setting and depositional palaeoenvironment of carbonaceous shale and lignite successions of Panandhro, northwestern Kutch Basin, Gujarat, Western India

    NASA Astrophysics Data System (ADS)

    Sahay, Vinay K.

    2011-03-01

    The objective of the present paper is to provide geochemical and palynological data to characterize lignites and carbonaceous shales from Panandhro, northwestern Kutch Basin, Gujarat, Western India, in terms of their hydrocarbon potential, thermal maturity, sequence stratigraphic settings and depositional palaeoenvironment. The samples, collected in Panandhro lignite mine, belong to Naredi Formation of Late Paleocene-Early Eocene age. The geochemical results are based on proximate analysis, ultimate analysis, X-ray diffraction and Rock-Eval py-rolysis analyses, whereas palynological data include palynofossil composition and thermal alteration index (TAI). The TOC, hydrogen index (HI), cracked hydrocarbon (S2), bitumen index (BI), quality index (QI), and the total genetic potential (S1+S2) values indicate that the studied lignites and carbonaceous shales have good source rock potential. The organic matter is predominantly of type II and type II/III kerogen, which has potential to generate oil as well as gas. Thermal maturity determined from thermal alteration index (TAI), T max and production index (PI) indicates that the organic matter is immature, and in the diagenesis stage of organic matter transformation. The deposition of the studied carbonaceous shales and lignites took place in palaeoenvironments varying from brackish mangrove to freshwater swamp. This study indicates that the proportion of ferns, palms, volatile matter content, S/C, H/C ratios, as well as the presence of siderite and quartz can be used as an indicator of accommodation trends in the coal depositional system. The Panandhro carbonaceous shales and lignites were deposited during the lowstand systems tract with many cycles of small magnitude trangressive-regressive phases. Thus, the geochemistry and ecological palynology are useful not only for the investigation of coal quality and origin, but also to infer accommodation space settings of the mire. This can be gainfully utilized in the coal

  18. Holocene Palaeoenvironment on Kamchatka

    NASA Astrophysics Data System (ADS)

    Diekmann, B.; Chapligin, B.; Dirksen, O.; Dirksen, V.; Hoff, U.; Meyer, H.; Nazarova, L.

    2013-12-01

    In the scope of the German-Russian research programme KALMAR (Kurile-Kamchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamics and Climate Interaction in Space and Time), Holocene lake-sediment records and peat sections were investigated on Kamchatka, to infer environmental changes related to subpolar climatic processes in the northwestern Pacific realm at the eastern Siberian margin. The research strategy followed a multi-proxy approach, using fossil bioindicators (diatoms, chironomids, pollen), stable-isotope geochemistry of diatoms, sedimentology, tephra chronology, and radiocarbon dating. The oldest sediments were retrieved from former proglacial Lake Sokoch, situated at the treeline at 495 m a.s.l. in the Ganalsky Ridge of southern central Kamchatka. Lacustrine sediment records and peat sections of mid- to late Holocene age were recovered from the up to 25 m deep Two-Yurts Lake and neighbouring smaller forest lakes and onshore areas, situated in a former proglacial basin at 275 m a.s.l. at the eastern flank of the Central Kamchatka Mountain Chain, the Sredinny Ridge. Our findings give evidence of longterm climate changes that suggest the existence of a warm and humid early Holocene climate optimum between roughly 9.0 and 4.5 ka BP, followed by climate deterioration of the neoglacial epoch in concert with summer cooling, glacial advances, and enhanced continentality. Two strong cooling episodes punctuated late Holocene climate development between 4.5 and 3.5 ka BP and during the last millennium, marking the prelude of neoglacial cooling and the Little Ice Age. This general development of Holocene climate on Kamchatka is in line with environmental changes in the neighbouring Sea of Okhotsk, where the pattern of sea-ice dynamics is consistent with early Holocene warmth and Neoglacial climate cooling. While the marine records from the Sea of Okhotsk mainly reflect winter conditions, our findings show that summer climate on Kamchatka shows a similar trend of temporal change. Meteorological observations and ice-core data from the second half of the last century show that both summer and winter climate conditions on Kamchatka are controlled by the complex interplay of the Pacific Decadal Oscillation and the Arctic Oscillation that both control the influence of maritime or continental air masses and the intensity of rain- or snow-bringing cyclones. We propose that Holocene climate variability on Kamchatka was mainly driven by external insolation forcing, changes in solar activity, and internal forcing by the relative position of the Aleutan Low.

  19. Recognition of deep-water benthic assemblages in the fossil record: Taphonomy and community characteristics of Louisiana continental slope petroleum seep assemblages

    SciTech Connect

    Callender, W.R.

    1992-01-01

    Chemoautotrophic benthic assemblages associated with petroleum seepage form the only substantial shell accumulations below storm wave base on the northern Gulf of Mexico shelf and slope. Five biofacies are associated with petroleum seepage, dominated respectively by vestimentiferan tubeworms, lucinid, thyasirid and vesicomyid clams and mytilid mussels. The taphonomy of petroleum seep death assemblages includes dissolution as the most pervasive mode of shell alteration. The dominant species in each assemblage reflect the taphonomic signature of the assemblage they dominate. The taphonomic attributes of petroleum seep death assemblages are similar to those of ancient autochthonous benthic assemblages. Paleoecological characteristics representative of cold seep assemblages include: high density-low diversity molluscan assemblages dominated by large individuals, high molluscan biomass concentrations aligned in linear trends, carbons with depleted [delta][sup 13]C values associated with faunally depauperate shales, laminated or massive sedimentary structures, variable articulation frequencies, poor shell preservation, and a trophic structure dominated by one trophic group. The Campanian Tepee Buttes share many paleoecological characteristics with recognized ancient seep assemblages. Methane and hydrogen sulfide-rich fluids from underlying strata were transported along fault conduits to supply a localized nutrient source for lucinid-dominated benthic communities. The Tepee Butte assemblages were dominated by dense accumulations of Nymphalucina occidentalis with moderate to high articulation frequencies. The lucinids probably used H[sub 2]S as a nutrient source. Cold seeps can be recognized in the fossil record, based on criteria developed by the study of modern cold seep death assemblages, because the paleoecological characteristics of cold seep assemblages are very conservative.

  20. Taphonomy and diversity of Middle Miocene decapod crustaceans from the Novohrad-Nógrad Basin, Slovakia, with remarks on palaeobiography

    PubMed Central

    Hyžný, Matúš; Hudáčková, Natália; Szalma, Štefan

    2016-01-01

    Decapod crustacean assemblages from the Middle Miocene (lower ‘Badenian’=Langhian) volcanoclastic Plášťovce Beds (Sebechleby Formation) in the Slovakian part of the Novohrad-Nógrad Basin comprise five species in five families (Callianassidae, Laomediidae, Munididae, Cancridae and Retroplumidae) and are dominated by the cancrid crab Tasadia carniolica (Bittner, 1884). Munida sp. constitutes the first record of this genus from Slovakia and the second from the European Neogene. Burrowing shrimp (Jaxea kuemeli Bachmayer, 1954) are associated with burrows tentatively attributed to this species. The occurrence of Retropluma slovenica Gašparič & Hyžný, 2014, previously recorded from the Lower Miocene of Slovenia, extends both the geographical distribution and stratigraphical range of the species. Differential decapod diversity at four localities in the Plášťovce area can be explained by collecting bias and palaeoenvironmental factors. The palaeosetting is interpreted as a muddy-bottom, nearshore zone with a water depth of approximately 100 m. Abundant articulated crabs suggest rapid burial. Third maxillipeds in open posture in some specimens may indicate respiratory stress of the animals, suggesting episodic events of rapid volcanoclastic flows responsible for killing crabs and promoting their preservation. Species composition of the decapod fauna of the Plášťovce Beds further strengthens similarities with Miocene faunas from the North Sea Basin. PMID:27499675

  1. Taxonomy, paleoecology and taphonomy of ground sloths (Xenarthra) from the Fairmead Landfill locality (Pleistocene: Irvingtonian) of Madera County, California

    NASA Astrophysics Data System (ADS)

    McDonald, H. Gregory; Dundas, Robert G.; Chatters, James C.

    2013-03-01

    The Fairmead Landfill locality contains a diverse middle Irvingtonian, (0.78-0.55 Ma), vertebrate fauna that includes three sloths, Megalonyx wheatleyi, Nothrotheriops shastensis and Paramylodon harlani. The co-occurrence of these three genera in a single fauna is relatively rare in both the Irvingtonian and Rancholabrean and this is only the fourth documented Irvingtonian fauna to contain all three sloth genera. The presence of the three different sloths, each of which had different ecological requirements, indicates the presence of a variety of different habitats at this time and a heterogeneous landscape. Preliminary analysis of pollen from the site supports the interpretation of the existence of a mosaic of plant communities, but a landscape dominated by a mesic grassland. This interpretation is also supported by the total faunal diversity that includes taxa associated with woodlands as well as open habitat and taphonomic differences in the preservation and relative abundance of the different sloths. Evolutionarily the Fairmead Landfill sloths show a suite of morphological, size and proportional characters that indicate they represent transitional populations between older and younger members of their respective lineages.

  2. Glycoproteins: Occurrence and Significance

    NASA Astrophysics Data System (ADS)

    Wittmann, Valentin

    Protein glycosylation is regarded as the most complex form of post-translational modification leading to a heterogeneous expression of glycoproteins as mixtures of glycoforms. This chapter describes the structure and occurrence of glycoproteins with respect to their glycan chains. Discussed are different carbohydrate-peptide linkages including GPI anchors, common structures of N- and O-glycans, and the structure of glycosaminoglycans contained in proteoglycans. Also covered are the bacterial cell wall polymer peptidoglycan and the glycopeptide antibiotics of the vancomycin group. Properties and functions of the glycans contained in glycoproteins are dealt with in the next chapter of this book.

  3. Occurrence of halogenated alkaloids.

    PubMed

    Gribble, Gordon W

    2012-01-01

    Once considered to be isolation artifacts or chemical "mistakes" of nature, the number of naturally occurring organohalogen compounds has grown from a dozen in 1954 to >5000 today. Of these, at least 25% are halogenated alkaloids. This is not surprising since nitrogen-containing pyrroles, indoles, carbolines, tryptamines, tyrosines, and tyramines are excellent platforms for biohalogenation, particularly in the marine environment where both chloride and bromide are plentiful for biooxidation and subsequent incorporation into these electron-rich substrates. This review presents the occurrence of all halogenated alkaloids, with the exception of marine bromotyrosines where coverage begins where it left off in volume 61 of The Alkaloids. Whereas the biological activity of these extraordinary compounds is briefly cited for some examples, a future volume of The Alkaloids will present full coverage of this topic and will also include selected syntheses of halogenated alkaloids. Natural organohalogens of all types, especially marine and terrestrial halogenated alkaloids, comprise a rapidly expanding class of natural products, in many cases expressing powerful biological activity. This enormous proliferation has several origins: (1) a revitalization of natural product research in a search for new drugs, (2) improved compound characterization methods (multidimensional NMR, high-resolution mass spectrometry), (3) specific enzyme-based and other biological assays, (4) sophisticated collection methods (SCUBA and remote submersibles for deep ocean marine collections), (5) new separation and purification techniques (HPLC and countercurrent separation), (6) a greater appreciation of traditional folk medicine and ethobotany, and (7) marine bacteria and fungi as novel sources of natural products. Halogenated alkaloids are truly omnipresent in the environment. Indeed, one compound, Q1 (234), is ubiquitous in the marine food web and is found in the Inuit from their diet of whale

  4. Record of the giant sloth Valgipes bucklandi (Lund, 1839) (Tardigrada, Scelidotheriinae) in Rio Grande do Norte state, Brazil, with notes on taphonomy and paleoecology

    NASA Astrophysics Data System (ADS)

    Pereira, Isabella Caroline dos Santos; Dantas, Mário André Trindade; Ferreira, Rodrigo Lopes

    2013-04-01

    This paper presents the first record of the species Valgipes bucklandi in Rio Grande do Norte state, in the Brazilian Intertropical Region (BIR). This occurrence extends the distribution of this taxon in the BIR. Taphonomic information recovered from this finding indicated that the carcass was probably exposed in a hot and dry environment, whereas carbon isotope data revealed that V. bucklandi had a browser diet (δ13C = -10.17‰), living in more closed environments.

  5. Alluvial systems as archives for environmental change at a Hominid site with Oldowan archaeological occurrences: the Homa Peninsula, southwestern Kenya

    NASA Astrophysics Data System (ADS)

    Vincent, Thomas; Whitfield, Elizabeth; Kirby, Jason; Hunt, Christopher; Bishop, Laura; Plummer, Thomas; Ditchfield, Peter

    2016-04-01

    The Homa Peninsula, southwestern Kenya, preserves fossiliferous sedimentary sequences dating to the Plio-Pleistocene. Evidence of hominids inhabiting an open grassland setting and utilising Oldowan tools has been reported here, as well as some of the oldest known traces of hominin activity. Reconstructions of the palaeoenvironment have suggested that alluvial and lake marginal environments on a grassy plain, between wooded slopes and a permanent water body might be plausible. However, these interpretations are based only on field sedimentological analyses and stable isotope analysis at a single site on the peninsula (Kanjera South). It is the aim of this study to utilise a multiproxy approach to develop our understanding of the palaeoenvironmental characteristics here. Sediments will also be characterized at a new site (Nyayanga) through field analyses, as well as through analyses of particle size, siliceous microfossils (diatoms, phytoliths and sponge spicules), pollen and stable isotopes. By utilizing this approach, new insights into the palaeoecology, palaeohydromorphology and palaeoclimate of the locale may be revealed, expanding the limited data available to palaeoanthropological studies of Oldowan occurrences in east Africa. Efforts to refine palaeoenvironmental reconstructions of Kanjera South through particle size analysis have shown that sediments in the lower beds of the sequence are characterised by poor sorting, a bimodal distribution and sand/silty-sand grade material. This suggests rapid deposition and/or a variable hydrological regime and may represent the role of relatively unconfined ephemeral channels in the transportation and deposition of sediments. Fluvial reworking of aeolian sediments, most likely during unconfined flood events may also have occurred.

  6. First natural occurrence of coesite

    USGS Publications Warehouse

    Chao, E.C.T.; Shoemaker, E.M.; Madsen, B.M.

    1960-01-01

    Coesite, the high-pressure polymorph of SiO2, hitherto known only as a synthetic compound, is identified as an abundant mineral in sheared Coconino sandstone at Meteor Crater, Arizona. This natural occurrence has important bearing on the recognition of meteorite impact craters in quartz-bearing geologic formations.

  7. The taphonomy of a Middle Devensian (MIS 3) vertebrate assemblage from Lynford, Norfolk, UK, and its implications for Middle Palaeolithic subsistence strategies

    NASA Astrophysics Data System (ADS)

    Schreve, Danielle C.

    2006-07-01

    The association of a rich lithic assemblage with a Middle Devensian mammalian assemblage at Lynford was initially thought indicative of a mammoth butchery locality, a rare occurrence for a European Middle Palaeolithic open site. However, taphonomic analyses suggest that the specimens have very different depositional histories and were incorporated into a palaeochannel in several stages. Most specimens are extremely fragmentary, probably the result of extensive trampling, and signs of weathering and root-damage provide further indications of exposure before burial. Carnivore damage is minimal but establishing the degree of interaction between the mammal fauna and alternative predators, such as Neanderthals, is problematic. Direct evidence of butchery is not present and the best indication of any form of mammoth exploitation lies in more circumstantial evidence such as the virtual absence of long bones from the main channel deposit and the mammoth age profiles. Instances of pathologies are also unusually common in the mammoths, implying that their greater vulnerability may have led to an accelerated demise either naturally or at the hands of a predator. The best evidence for direct faunal exploitation at the site is from green bone fractures and broken teeth that suggest marrow extraction in horse, reindeer and woolly rhinoceros. Copyright

  8. Vertebrate fossil-bearing paleosol units (Willwood Formation, Lower Eocene, Northwest Wyoming, U.S.A.): Implications for taphonomy, biostratigraphy, and assemblage analysis

    USGS Publications Warehouse

    Bown, T.M.; Kraus, M.J.

    1981-01-01

    In the lower 300 m of the fluvial Willwood Formation of northwest Wyoming, most large concentrations of vertebrate fossils consist of disarticulated and broken skeletal remains that occur in widespread, tubular, thin (2 cm-1 m) greenish- and bluish-gray mudstones that are low in percentage of free iron, aluminum, and manganese, relatively high in percentages of organic carbon, and often show evidence of clay eluviation. These units lie atop sesquioxide-rich, sometimes clay-illuviated variegated unit (red, yellow, purple, and mottled variants) and are relicts of the A horizons of podzolic spodosols (aquods). The wide distribution of bone fragments, the numerical proportions of bone elements, weathering of the fragments, and biogenic evidence indicate the vertebrate remains accumulated gradually as litter on the surface of the soils and became incorporated into the A horizon. The bones were disarticulated, broken, and otherwise disturbed by the action of scavengers prior to burial. Occurrence of abundant vertebrate remains in discrete, readily identifiable, and widespread paleosol units makes these units valuable biostratigraphic markers (zonules, faunules). Evidence of geologically short-term lag accumulation of the bones is important to assemblage analysis; the paleosol concentrations result from attritional mortalities that more closely reflect composition of the life assemblage than do remains concentrated by fluvial transport or predators. ?? 1981.

  9. Occurrence reporting and processing of operations information

    SciTech Connect

    1997-07-21

    DOE O 232.1A, Occurrence Reporting and Processing of Operations Information, and 10 CFR 830.350, Occurrence Reporting and Processing of Operations Information (when it becomes effective), along with this manual, set forth occurrence reporting requirements for Department of Energy (DOE) Departmental Elements and contractors responsible for the management and operation of DOE-owned and -leased facilities. These requirements include categorization of occurrences related to safety, security, environment, health, or operations (``Reportable Occurrences``); DOE notification of these occurrences; and the development and submission of documented follow-up reports. This Manual provides detailed information for categorizing and reporting occurrences at DOE facilities. Information gathered by the Occurrence Reporting and processing System is used for analysis of the Department`s performance in environmental protection, safeguards and security, and safety and health of its workers and the public. This information is also used to develop lessons learned and document events that significantly impact DOE operations.

  10. Colorado quartz: occurrence and discovery

    USGS Publications Warehouse

    Kile, D.E.; Modreski, P.J.; Kile, D.L.

    1991-01-01

    The many varieties and associations of quartz found throughout the state rank it as one of the premier worldwide localities for that species. This paper briefly outlines the historical importance of the mineral, the mining history and the geological setting before discussing the varieties of quartz present, its crystallography and the geological enviroments in which it is found. The latter include volcanic rocks and near surface igneous rocks; pegmatites; metamorphic and plutonic rocks; hydrothermal veins; skarns and sedimentary deposits. Details of the localities and mode of occurrence of smoky quartz, amethyst, milky quartz, rock crystal, rose quartz, citrine, agate and jasper are then given. -S.J.Stone

  11. The taphonomy of unmineralised Palaeozoic fossils preserved as siliciclastic moulds and casts, and their utility in assessing the interaction between environmental change and the fossil record

    NASA Astrophysics Data System (ADS)

    MacGabhann, Breandán; Schiffbauer, James; Hagadorn, James; Van Roy, Peter; Lynch, Edward; Morrsion, Liam; Murray, John

    2015-04-01

    biopolymers, and that these tissues were preferentially fossilised by the formation of an early diagenic mould directly on the organic surfaces. Excess divalent iron ions, produced during decay of more labile tissues by means of bacterial iron reduction, would have adsorbed to anionic functional groups in the biopolymeric tissues. This would have provided a ready substrate for the formation and growth of such an early diagenic mineralised mould, including aluminosilicate minerals produced via reaction with seawater silica and metal ions, and iron sulphide minerals produced via reaction with hydrogen sulphide and free sulphur produced from seawater sulphate through bacterial sulphate reduction associated with further decay. Subsequent weathering would have oxidised such iron sulphides to oxides and oxyhydroxides. This taphonomic model supports the lack of utility of the eldonid palaeobiological record in analysing environmental influence on biological communities, due to the lack of preservation of key anatomical components. However, it also suggests that the very occurrence of fossils preserved in this style is dependent on extrinsic palaeoenvironmental factors - including pH, Eh, and the concentration of other ions in the contemporaneous seawater. Analyses of the distribution of fossils preserved in this style may therefore provide information on ambient conditions which may have affected the distribution of contemporaneous mineralised fossils, potentially allowing a more complete analysis of the effects of palaeoenvironmental change on fossil ecosystems.

  12. Lineaments and Mineral Occurrences in Pennsylvania

    NASA Technical Reports Server (NTRS)

    Mcmurtry, G. J.; Petersen, G. W. (Principal Investigator); Kowalik, W. S.; Gold, D. P.

    1975-01-01

    The author has identified the following significant results. A conservative lineament map of Pennsylvania interpreted from ERTS-1 channel 7 (infrared) imagery and Skylab photography was compared with the distribution of known metallic mines and mineral occurrences. Of 383 known mineral occurrences, 116 show a geographical association to 1 km wide lineaments, another 24 lie at the intersection of two lineaments, and one lies at the intersection of three lineaments. The Perkiomen Creek lineament in the Triassic Basin is associated with 9 Cu-Fe occurrences. Six Pb-Zn occurrences are associated with the Tyrone-Mount Union lineament. Thirteen other lineaments are associated with 3, 4, or 5 mineral occurrences each.

  13. Global occurrences of gas hydrate

    USGS Publications Warehouse

    Kvenvolden, K.A.; Lorenson, T.D.

    2001-01-01

    Natural gas hydrate is found worldwide in sediments of outer continental margins of all oceans and in polar areas with continuous permafrost. There are currently 77 localities identified globally where geophysical, geochemical and/or geological evidence indicates the presence of gas hydrate. Details concerning individual gas-hydrate occurrences are compiled at a new world-wide-web (www) site (http://walrus.wr.usgs.gov/globalhydrate). This site has been created to facilitate global gas-hydrate research by providing information on each of the localities where there is evidence for gas hydrate. Also considered are the implications of gas hydrate as a potential (1) energy resource, (2) factor in global climate change, and (3) geohazard.

  14. On-off intermittency in earthquake occurrence

    SciTech Connect

    Bottiglieri, M.; Godano, C.

    2007-02-15

    The clustered occurrence of earthquakes is viewed as an intermittent phenomenon, interpreting the clusters of events as chaotic bursts combined to the Poissonian occurrence of background seismicity. In particular, we suggest that it can be interpreted as an example of on-off intermittency. This kind of intermittency is parameter driven and exhibits certain universal statistical properties. The study of a Californian catalogue allows to interpret earthquake occurrence as an on-off intermittent phenomenon. Our results suggest the existence of a branching mechanism in earthquake occurrence well explained by epidemic type models.

  15. Foreshock occurrence before large earthquakes

    USGS Publications Warehouse

    Reasenberg, P.A.

    1999-01-01

    Rates of foreshock occurrence involving shallow M ??? 6 and M ??? 7 mainshocks and M ??? 5 foreshocks were measured in two worldwide catalogs over ???20-year intervals. The overall rates observed are similar to ones measured in previous worldwide and regional studies when they are normalized for the ranges of magnitude difference they each span. The observed worldwide rates were compared to a generic model of earthquake clustering based on patterns of small and moderate aftershocks in California. The aftershock model was extended to the case of moderate foreshocks preceding large mainshocks. Overall, the observed worldwide foreshock rates exceed the extended California generic model by a factor of ???2. Significant differences in foreshock rate were found among subsets of earthquakes defined by their focal mechanism and tectonic region, with the rate before thrust events higher and the rate before strike-slip events lower than the worldwide average. Among the thrust events, a large majority, composed of events located in shallow subduction zones, had a high foreshock rate, while a minority, located in continental thrust belts, had a low rate. These differences may explain why previous surveys have found low foreshock rates among thrust events in California (especially southern California), while the worldwide observations suggests the opposite: California, lacking an active subduction zone in most of its territory, and including a region of mountain-building thrusts in the south, reflects the low rate apparently typical for continental thrusts, while the worldwide observations, dominated by shallow subduction zone events, are foreshock-rich. If this is so, then the California generic model may significantly underestimate the conditional probability for a very large (M ??? 8) earthquake following a potential (M ??? 7) foreshock in Cascadia. The magnitude differences among the identified foreshock-mainshock pairs in the Harvard catalog are consistent with a uniform

  16. UMTRA project list of reportable occurrences

    SciTech Connect

    Not Available

    1994-04-01

    This UMTRA Project List of Reportable occurrences is provided to facilitate efficient categorization of reportable occurrences. These guidelines have been established in compliance with DOE minimum reporting requirements under DOE Order 5000.3B. Occurrences are arranged into nine groups relating to US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project operations for active sites. These nine groupings are provided for reference to determined whether an occurrence meets reporting requirement criteria in accordance with the minimum reporting requirements. Event groups and significance categories that cannot or will not occur, and that do not apply to UMTRA Project operations, are omitted. Occurrence categorization shall be as follows: Group 1. Facility Condition; Group 2. Environmental; Group 3. Personnel Safety; Group 4. Personnel Radiation Protection; Group 5. Safeguards and Security; Group 6. Transportation; Group 7. Value Basis Reporting; Group 8. Facility Status; and Group 9. Cross-Category Items.

  17. Post-cremation taphonomy and artifact preservation.

    PubMed

    Warren, Michael W; Schultz, John J

    2002-05-01

    Contemporary commercial cremation is a reductive taphonomic process that represents one of the most extreme examples of postmortem human alteration of bone. The thorough reduction and fragmentation of cremated human remains often leaves little biological evidence of diagnostic value. Instead, non-osseous artifacts often provide the best evidence of the origin of the cremated remains, the identity of the decedent, and commingling of the remains of more than one individual. Once human remains have been cremated they are most commonly placed into a processor and reduced into small fragments and fine ash suitable for inurnment or scattering. The type of processor determines the size and utility of the particulates and artifacts available for analysis. The newest type of processors have changed the manner and degree of postmortem bone modification and altered the preservation of diagnostic bone fragments and cremation artifacts. This paper addresses the impact of the newest cremation procedures on forensic analysis of cremated remains.

  18. Pollen taphonomy in a canyon stream

    NASA Astrophysics Data System (ADS)

    Fall, Patricia L.

    1987-11-01

    Surface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae- Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.

  19. Hydrothermal Occurrences in Gusev Crater

    NASA Astrophysics Data System (ADS)

    Ruff, S. W.; Farmer, J. D.; Milliken, R.; Mills, V. W.; Shock, E.

    2011-12-01

    Exploration of the Gusev crater landing site by the Spirit rover has revealed for the first time, in situ evidence of hydrothermal activity on Mars. Most compelling are eroded outcrops of opaline silica found adjacent to "Home Plate" [1], an eroded stack of volcaniclastic deposits stratigraphically overlain by a vesicular basalt unit [2]. Recent work [3] demonstrates that the silica outcrops occur in a stratiform unit that possibly surrounds Home Plate. The outcrops are dominated by opal-A with no evidence for diagenesis to other silica phases. No other hydrous or alteration phases have been identified within the outcrops; most notable is a lack of sulfur phases. The outcrops have porous and in some cases, brecciated microtextures. Taken together, these observations support the interpretation that the opaline silica outcrops were produced in a hot spring or perhaps geyser environment. In this context, they are silica sinter deposits precipitated from silica-rich hydrothermal fluids, possibly related to the volcanism that produced the Home Plate volcanic rocks. On Earth, debris aprons in which sinter is brecciated, reworked, and cemented, are common features of hot springs and geysers and are good analogs for the Martian deposits. An alternative hypothesis is that the silica resulted from acid-sulfate leaching of precursor rocks by fumarolic steam condensates. But stratigraphic, textural, and chemical observations tend to diminish this possibility [3]. We are conducting extensive laboratory and field investigations of silica from both hot spring/geyser and fumarole environments to understand the full range of mineralogical, chemical, textural, and morphological variations that accompany its production, in order to shed more light on the Home Plate occurrence. The recent discovery of abundant Mg-Fe carbonate (16-34 wt%) in outcrops named Comanche provides possible evidence for additional hydrothermal activity in Gusev [4]. However, the carbonate is hosted by olivine

  20. Managing occurrence branching in qualitative simulation

    SciTech Connect

    Tokuda, L.

    1996-12-31

    Qualitative simulators can produce common sense abstractions of complex behaviors given only partial knowledge about a system. One of the problems which limits the applicability of qualitative simulators is the intractable branching of successor states encountered with model of even modest size. Some branches may be unavoidable due to the complex nature of a system. Other branches may be accidental results of the model chosen. A common source of intractability is occurrence branching. Occurrence branching occurs when the state transitions of two variables are unordered with respect to each other. This paper extends the QSIM model to distinguish between interesting occurrence branching and uninteresting occurrence branching. A representation, algorithm, and simulator for efficiently handling uninteresting branching is presented.

  1. Brief Communication: Freaque wave occurrences in 2013

    NASA Astrophysics Data System (ADS)

    Liu, P. C.

    2014-11-01

    Documenting freaque waves when they occured around the globe in 2013 is based here on news reports on the internet. It was found that there were a total 22 cases of freaque waves in 2013, based on those reported in clearly-defined physically specific environments. There were three cases in the deep ocean, six in nearshore areas, seven on sandy beaches, and seven on rocky shore areas. Note that most of the academic research has been on freaque waves in the deep ocean, which accounts for 13% of all occurrences. The majority of reported occurrences, 87%, are in the nearshore areas or along the beach area. Geographically, these cases are also fairly evenly spread around the globe. As of now, there is no general knowledge regarding the frequency of occurrence of these freaque waves, so that one may assume that 2013 was a customary year for freaque wave occurrences.

  2. Occurrence and distribution of Indian primates

    USGS Publications Warehouse

    Karanth, K.K.; Nichols, J.D.; Hines, J.E.

    2010-01-01

    Global and regional species conservation efforts are hindered by poor distribution data and range maps. Many Indian primates face extinction, but assessments of population status are hindered by lack of reliable distribution data. We estimated the current occurrence and distribution of 15 Indian primates by applying occupancy models to field data from a country-wide survey of local experts. We modeled species occurrence in relation to ecological and social covariates (protected areas, landscape characteristics, and human influences), which we believe are critical to determining species occurrence in India. We found evidence that protected areas positively influence occurrence of seven species and for some species are their only refuge. We found evergreen forests to be more critical for some primates along with temperate and deciduous forests. Elevation negatively influenced occurrence of three species. Lower human population density was positively associated with occurrence of five species, and higher cultural tolerance was positively associated with occurrence of three species. We find that 11 primates occupy less than 15% of the total land area of India. Vulnerable primates with restricted ranges are Golden langur, Arunachal macaque, Pig-tailed macaque, stump-tailed macaque, Phayre's leaf monkey, Nilgiri langur and Lion-tailed macaque. Only Hanuman langur and rhesus macaque are widely distributed. We find occupancy modeling to be useful in determining species ranges, and in agreement with current species ranking and IUCN status. In landscapes where monitoring efforts require optimizing cost, effort and time, we used ecological and social covariates to reliably estimate species occurrence and focus species conservation efforts. ?? Elsevier Ltd.

  3. Recognition of the Script in Serbian Documents Using Frequency Occurrence and Co-Occurrence Analysis

    PubMed Central

    Brodić, Darko; Milivojević, Zoran N.; Maluckov, Čedomir A.

    2013-01-01

    Any document in Serbian language can be written in two different scripts: Latin or Cyrillic. Although characteristics of these scripts are similar, some of their statistical measures are quite different. The paper proposed a method for the extraction of certain script from document according to the occurrence and co-occurrence of the script types. First, each letter is modeled with the certain script type according to characteristics concerning its position in baseline area. Then, the frequency analysis of the script types occurrence is performed. Due to diversity of Latin and Cyrillic script, the occurrence of modeled letters shows substantial statistics dissimilarity. Furthermore, the co-occurrence matrix is computed. The analysis of the co-occurrence matrix draws a strong margin as a criteria to distinguish and recognize the certain script. The proposed method is analyzed on the case of a database which includes different types of printed and web documents. The experiments gave encouraging results. PMID:24385887

  4. Forest Pest Occurrence Predictionca-Markov Model

    NASA Astrophysics Data System (ADS)

    Xie, Fangyi; Zhang, Xiaoli; Chen, Xiaoyan

    Since the spatial pattern of forest pest occurrence is determined by biological characteristics and habitat conditions, this paper introduced construction of a cellular automaton model combined with Markov model to predicate the forest pest occurrence. Rules of the model includes the cell states rules, neighborhood rules and transition rules which are defined according to the factors from stand conditions, stand structures, climate and the influence of the factors on the state conversion. Coding for the model is also part of the implementations of the model. The participants were designed including attributes and operations of participants expressed with a UML diagram. Finally, the scale issues on forest pest occurrence prediction, of which the core are the prediction of element size and time interval, are partly discussed in this paper.

  5. Technique for Evaluating Multiple Probability Occurrences /TEMPO/

    NASA Technical Reports Server (NTRS)

    Mezzacappa, M. A.

    1970-01-01

    Technique is described for adjustment of engineering response information by broadening the application of statistical subjective stimuli theory. The study is specifically concerned with a mathematical evaluation of the expected probability of relative occurrence which can be identified by comparison rating techniques.

  6. Species occurrence data for the nation

    USGS Publications Warehouse

    ,

    2015-09-28

    BISON's size is unprecedented, including records for most living species found in the U.S. and encompassing the efforts of more than a million professional and citizen scientists. And the vast majority of BISON's species occurrence records are specific locations, not just county or state records.

  7. Tectonic implications of Archean anorthosite occurrences

    NASA Technical Reports Server (NTRS)

    Phinney, W. C.; Morrison, D. A.; Maczuga, D. E.

    1988-01-01

    The occurrences of megacrystic anorthosite and basalt in a variety of geologic settings were reviewed and it was found that these rock types occur in a variety of tectonic settings. Anorthosites and megacrystic basalts are petrogenetically related and are found in oceanic volcanic crust, cratons, and shelf environments. Although megacrystic basalts are most common in Archean terranes, similar occurrences are observed in rocks of early Proterozoic age, and even in young terranes such as the Galapagos hotspot. Based on inferences from experimental petrology, all of the occurrences are apparently associated with similar parental melts that are relatively Fe-rich tholeiites. The megacrystic rocks exhibit a two- (or more)-stage development of plagioclase, with the megacrysts having relatively uniform composition produced under nearly isothermal and isochemical conditions over substantial periods of time. The anorthosites appear to have intruded various crustal levels from very deep to very shallow. The petrogenetic indicators, however, suggest that conditions of formation of the Precambrian examples were different from Phanerozoic occurrences.

  8. [T-2 toxin: occurrence and detection].

    PubMed

    Dohnal, V; Jezková, A; Kuca, K; Jun, D

    2007-07-01

    The paper is focused on the occurrence and methods for the detection of T-2 toxin, one of the most toxic trichothecene Fusarium mycotoxin. Due to its physical-chemical properties and high toxicity, T-2 toxin is classified as a potential biological warfare agent. PMID:17969315

  9. A Sweet Tasting Demonstration of Random Occurrences.

    ERIC Educational Resources Information Center

    Christopher, Andrew N.; Marek, Pam

    2002-01-01

    Discusses a game in which students must guess the flavor of LifeSaver candy without the aid of sight and smell. Explains that this demonstration assists students to understand the phenomenon of random occurrences. Describes how the presentation is conducted as well as the outcomes of the demonstration. (CMK)

  10. Tetrahymanol: Its widespread occurrence and geochemical significance

    NASA Astrophysics Data System (ADS)

    Venkatesan, M. I.

    1989-11-01

    The occurrence of tetrahymanol (gammaceran-3β-ol) in sediments from various marine depositional environments such as the Santa Monica Basin and Palos Verdes shelf (southern California Bight), the Santa Barbara Basin (off the northern California Borderland), the Atlantic shelf, slope, and rise, and the Antarctic region, as well as in bacterial/algal mats from the Santa Barbara Basin and Baja California, together with its detection in sediments from the Peru upwelling region (ODP Leg 112) and Baffin Bay (ODP Leg 105) suggests that tetrahymanol occurs ubiquitously in marine samples. Tetrahymanol is the only known likely biological precursor of gammacerane, which is found in many petroleums and shales. The common occurrence of tetrahymanol in marine environments implies that primitive organisms similar to Tetrahymena, or organisms other than Tetrahymena (other protozoa, bacteria?), are also likely to contain this compound. Its isomer, diplopterol, has also been detected in several sediment sections.

  11. Idaho National Laboratory Quarterly Occurrence Analysis

    SciTech Connect

    Mitchell, Lisbeth Ann

    2015-11-01

    This report is published quarterly by the Idaho National Laboratory (INL) Quality and Performance Management Organization. The Department of Energy (DOE) Occurrence Reporting and Processing System (ORPS), as prescribed in DOE Order 232.2, “Occurrence Reporting and Processing of Operations Information,” requires a quarterly analysis of events, both reportable and not reportable, for the previous 12 months. This report is the analysis of 85 reportable events (18 from the 4th Qtr FY-15 and 67 from the prior three reporting quarters), as well as 25 other issue reports (including events found to be not reportable and Significant Category A and B conditions) identified at INL during the past 12 months (8 from this quarter and 17 from the prior three quarters).

  12. Mine and mineral occurrences of Afghanistan

    USGS Publications Warehouse

    Orris, G.J.; Bliss, J.D.

    2002-01-01

    This inventory of more than 1000 mines and mineral occurrences in Afghanistan was compiled from published literature and the files of project members of the National Industrial Minerals project of the U.S. Geological Survey. The compiled data have been edited for consistency and most duplicates have been deleted. The data cover metals, industrial minerals, coal, and peat. Listings in the table represent several levels of information, including mines, mineral showings, deposits, and pegmatite fields.

  13. Mycotoxins: occurrence, toxicology, and exposure assessment.

    PubMed

    Marin, S; Ramos, A J; Cano-Sancho, G; Sanchis, V

    2013-10-01

    Mycotoxins are abiotic hazards produced by certain fungi that can grow on a variety of crops. Consequently, their prevalence in plant raw materials may be relatively high. The concentration of mycotoxins in finished products is usually lower than in raw materials. In this review, occurrence and toxicology of the main mycotoxins are summarised. Furthermore, methodological approaches for exposure assessment are described. Existing exposure assessments, both through contamination and consumption data and biomarkers of exposure, for the main mycotoxins are also discussed.

  14. Occurrence of ultrasonic cavitation in sewage sludge

    NASA Astrophysics Data System (ADS)

    Zielewicz-Madej, E.; Sorys, P.

    2006-11-01

    The study revealed considerable differences in the susceptibility of the sludge to preliminary treatment by two kind of mixing and expressed as changes in the initial properties of the sludge and thus conditions for the occurrence of ultrasonic disintegration in particular sludge from wastewater treatment plants G, K andZ. The susceptibility of sludge to ultrasounds which depends on the sludge properties was explained by the higher COD of dissolved matter after ultrasonic disintegration of sludge.

  15. [Occurrence of allergens on hospital premises].

    PubMed

    Andersen, U M; Osterballe, O

    2000-01-24

    The occurrence of allergens from the house-dust mites Der p 1, Der f 1 and Der m, and from dogs (Can f 1) and cats (Fel d 1) was assessed in Viborg Hospital. Three hundred samples collected in a standardized manner were analysed for allergens by ELISA technique. In only one dust sample was the total occurrence of mite allergens marginally above the sensitization threshold level of 2,000 ng mite allergens/g dust. For Fel d 1 a threshold level for sensitization or symptoms of 8,000 ng Fel d 1/g dust has been proposed; none of the dust samples contained this concentration. A low occurrence of Can f 1 was found. One dust sample contained 8,902 ng Can f 1, while the remainder exhibited lower concentrations. Efficient cleaning and adequate ventilation can reduce allergens in public buildings, but it is impossible to remove all allergens from upholstered furniture. Avoidance of such furniture in wards and outpatient departments which receive allergic patients might be considered.

  16. Meteotsunami occurrence frequency along the Mediterranean coasts

    NASA Astrophysics Data System (ADS)

    Masina, Marinella; Archetti, Renata; Lamberti, Alberto

    2016-04-01

    A number of research studies describe exceptional destructive meteotsunami events since long time whereas no systematic database is available of moderate events because sea level data were recorded with insufficient resolution. Sea level measurements recently collected with high sampling rate, one per minute or less, by tide gauges positioned along the Mediterranean coasts are examined, aiming to analyze the occurrence of oscillation events in the tsunami frequency range. Sea level data from operating tide stations inside the Mediterranean basin are made publicly available through the Intergovernmental Oceanographic Commission Sea Level Monitoring Facility web site (http://www.ioc-sealevelmonitoring.org/). After the implementation of a rigorous quality check procedure to the raw water level time series, Hilbert transform is applied to two hour high-pass filtered observations to identify tsunami-like oscillation events. Events of seismic origin are identified by consistency between earthquake occurrence and tsunami wave travel time from the earthquake epicenter to the specific tide gauge. Similar analyses are performed to exclude sea waves induced harbor seiches events. A list of probable meteotsunami episodes occurred in the Mediterranean region is so compiled and their occurrence frequency and intensity statistics are evaluated at the different tide gauge sites over the time period of high frequency water level data availability ranging from five to seven years. The effects of atmospheric conditions and seabed topography are discussed. Detection and characterization of meteotsunamis, both of exceptional character and of weak intensity, represent an essential step toward improved assessments of coastal flooding risk along the Mediterranean coasts.

  17. Occurrences and Effects of Drought across Africa

    NASA Astrophysics Data System (ADS)

    Mwangi, M. N.

    2009-12-01

    Drought is a common occurrence in Africa and its effects vary temporally and spatially across the continent. The objective of this paper is to synthesize available information on droughts in Africa in order to discern emerging trends vis-à-vis spatiotemporal occurrences, impacts and adaptation. Drought forcings in the Sahelian region and southern Africa are predominately related to the passage of mid-latitude air masses while in locations near the equator is strongly linked to the position of ITCZ, except perhaps in the deserts where albedo may predominate. The review shows that drought occurrences have increased both temporally and spatially; its effects on the society vary across scales, and are influenced by political, economic, social, cultural, and ecological factors. The drought occurrence and its impacts varied spatially and temporally. The effect of drought also varied with socioeconomic sector; agriculture and pastoralism were the widely reported. The greater horn of Africa, specifically Kenya, has the most continuous record of droughts. The synthesis also reveals that a suite of drought adaptation strategies exists at the local scale; in contrasts, at the aggregate scale, coping strategies are scarce. Drought management tailored for specific livelihood system or societies are non-existent. The study found that occurrence of drought alongside issues related to the multiscale political economy affect the viability of most adaptation strategies used by societies across Africa. Drought management has been silent on the social, political, and economic dimensions that reasonably aggravate the vulnerability of lives and livelihood systems to this climatic hazard. The effect of drought and social pressures is relational and simultaneous to such a degree that differential vulnerability among communities across Africa is to be expected. Although scenarios about rainfall and drought vis-à-vis Africa are largely contested there is a general indication that most

  18. An Index to PGE-Ni-Cr Deposits and Occurrences in Selected Mineral-Occurrence Databases

    USGS Publications Warehouse

    Causey, J. Douglas; Galloway, John P.; Zientek, Michael L.

    2009-01-01

    Databases of mineral deposits and occurrences are essential to conducting assessments of undiscovered mineral resources. In the USGS's (U.S. Geological Survey) global assessment of undiscovered resources of copper, potash, and the platinum-group elements (PGE), only a few mineral deposit types will be evaluated. For example, only porphyry-copper and sediment-hosted copper deposits will be considered for the copper assessment. To support the global assessment, the USGS prepared comprehensive compilations of the occurrences of these two deposit types in order to develop grade and tonnage models and delineate permissive areas for undiscovered deposits of those types. This publication identifies previously published databases and database records that describe PGE, nickel, and chromium deposits and occurrences. Nickel and chromium were included in this overview because of the close association of PGE with nickel and chromium mineralization. Users of this database will need to refer to the original databases for detailed information about the deposits and occurrences. This information will be used to develop a current and comprehensive global database of PGE deposits and occurrences.

  19. The Occurrence of Erionite at Yucca Mountain

    SciTech Connect

    NA

    2004-07-01

    The naturally-occurring zeolite mineral erionite has a fibrous morphology and is a known human carcinogen (inhalation hazard). Erionite has been found typically in very small quantities and restricted occurrences in the course of mineralogic characterization of Yucca Mountain as a host for a high-level nuclear waste repository. The first identification of erionite was made in 1984 on the basis of morphology and chemical composition and later confirmed by X-ray diffraction analysis. It was found in the lower vitrophyre (Tptpv3) of the Topopah Spring Tuff in a borehole sidewall sample. Most erionite occurrences identified at Yucca Mountain are in the Topopah Spring Tuff, within an irregular zone of transition between the lower boundary of devitrified tuff and underlying glassy tuff. This zone is fractured and contains intermingled devitrified and vitric tuff. In 1997, a second host of erionite mineralization was identified in the Exploratory Studies Facility within and adjacent to a high-angle fracture/breccia zone transgressing the boundary between the lowermost devitrified tuff (Tpcplnc) and underlying moderately welded vitric tuff (Tpcpv2) of the Tiva Canyon Tuff. The devitrified-vitric transition zones where erionite is found tend to have complex secondary-mineral assemblages, some of very localized occurrence. Secondary minerals in addition to erionite may include smectite, heulandite-clinoptilolite, chabazite, opal-A, opal-CT, cristobalite, quartz, kenyaite, and moganite. Incipient devitrification within the Topopah Spring Tuff transition zone includes patches that are highly enriched in potassium feldspar relative to the precursor volcanic glass. Geochemical conditions during glass alteration may have led to local evolution of potassium-rich fluids. Thermodynamic modeling of zeolite stability shows that erionite and chabazite stability fields occur only at aqueous K concentrations much higher than in present Yucca Mountain waters. The association of erionite

  20. Global potential of dust devil occurrence

    NASA Astrophysics Data System (ADS)

    Jemmett-Smith, Bradley; Marsham, John; Knippertz, Peter; Gilkeson, Carl

    2014-05-01

    Mineral dust is a key constituent in the climate system. Airborne mineral dust forms the largest component of the global aerosol budget by mass and subsequently affects climate, weather and biogeochemical processes. There remains large uncertainty in the quantitative estimates of the dust cycle. Dry boundary-layer convection serves as an effective mechanism for dust uplift, typically through a combination of rotating dust devils and non-rotating larger and longer-lived convective plumes. These microscale dry-convective processes occur over length scales of several hundred metres or less. They are difficult to observe and model, and therefore their contribution to the global dust budget is highly uncertain. Using an analytical approach to extrapolate limited observations, Koch and Renno (2006) suggest that dust devils and plumes could contribute as much as 35%. Here, we use a new method for quantifying the potential of dust devil occurrence to provide an alternative perspective on this estimate. Observations have shown that dust devil and convective plume occurrence is favoured in hot arid regions under relatively weak background winds, large ground-to-air temperature gradients and deep dry convection. By applying such known constraints to operational analyses from the European Centre for Medium Range Weather Forecasts (ECMWF), we provide, to the best of the authors' knowledge, the first hourly estimates of dust devil occurrence including an analysis of sensitivity to chosen threshold uplift. The results show the expected diurnal variation and allow an examination of the seasonal cycle and day-to-day variations in the conditions required for dust devil formation. They confirm that desert regions are expected to have by far the highest frequency of dry convective vortices, with winds capable of dust uplift. This approach is used to test the findings of Koch and Renno (2006). Koch J., Renno N. (2006). The role of convective plumes and vortices on the global aerosol

  1. Electric pulses some minutes before earthquake occurrences

    SciTech Connect

    Varotsos, P. A.; Sarlis, N. V.; Skordas, E. S.; Lazaridou, M. S.

    2007-02-05

    Electric and magnetic pulses are measured shortly (some minutes) before earthquakes. These pulses differ greatly from the seismic electric signals, which have appreciably longer lead times (days to months). In the case of 1995 Grevena-Kozani earthquake with a magnitude of 6.8, the time difference of {approx_equal}1 s was observed between the recordings of the electric and magnetic components at Ioannina station, providing further support that the pulses were not from local man-made source but most probably from the epicentral area about 100 km away. A tentative explanation of the phenomenon is proposed considering what happens in the very last stage before the earthquake occurrence.

  2. Universality in Solar Flare and Earthquake Occurrence

    SciTech Connect

    De Arcangelis, L.; Godano, C.; Lippiello, E.; Nicodemi, M.

    2006-02-10

    Earthquakes and solar flares are phenomena involving huge and rapid releases of energy characterized by complex temporal occurrence. By analyzing available experimental catalogs, we show that the stochastic processes underlying these apparently different phenomena have universal properties. Namely, both problems exhibit the same distributions of sizes, interoccurrence times, and the same temporal clustering: We find after flare sequences with power law temporal correlations as the Omori law for seismic sequences. The observed universality suggests a common approach to the interpretation of both phenomena in terms of the same driving physical mechanism.

  3. Exudate gums: occurrence, production, and applications.

    PubMed

    Verbeken, D; Dierckx, S; Dewettinck, K

    2003-11-01

    This paper presents a review of the industrially most relevant exudate gums: gum arabic, gum karya, and gum tragacanth. Exudate gums are obtained as the natural exudates of different tree species and exhibit unique properties in a wide variety of applications. This review covers the chemical structure, occurrence and production of the different gums. It also deals with the size and relative importance of the various players on the world market. Furthermore, it gives an overview of the main application fields of the different gums, both food and non-food.

  4. Concurrent Occurrence of Mucocele and Pyogenic Granuloma

    PubMed Central

    Kim, Jae-Hong; Park, Hwa-young; Hong, Seung Phil

    2011-01-01

    A mucocele is a common, benign lesion of the oral cavity that develops following the extravasation or retention of mucous from a major or minor salivary gland. A pyogenic granuloma (PG) is also a common, benign condition characterized by proliferating capillaries that affect the skin and mucous membranes. The concurrent occurrence of a mucocele and a PG lesion has rarely been reported in the medical literature. This case study reports such a finding in a 16-year-old patient who presented to our department. PMID:22028553

  5. Taxonomical and geographical occurrence of Libyans scorpions.

    PubMed

    Zourgui, L; Maammar, M; Emetris, R

    2008-01-01

    Nine different species of scorpions can be recognized from more than 5000 samples collected from different areas in Libya: Leiurus quinquestriatus, Androctonus bicolor, Androctonus australis, Androctonus amoreuxi, Buthacus leptochelys, Buthus occitanus, Buthacus arenicola, Orthochirus innesi and Scorpio maurus. The geographical occurrence showed that Leiurus quinquestriatus seems to be restricted to the Southern areas. On the contrary, Buthus occitanus was found in the costal regions. Other species such as Androctonus were widely spread in all regions. Buthacus Leptochelys, Orthochirus innesi and Scorpio maurus were found, in the East (Aujlah, Jalu), the South (Wadi-Atbah) and the Western cost of Libya respectively. PMID:19469419

  6. Universality in solar flare and earthquake occurrence.

    PubMed

    de Arcangelis, L; Godano, C; Lippiello, E; Nicodemi, M

    2006-02-10

    Earthquakes and solar flares are phenomena involving huge and rapid releases of energy characterized by complex temporal occurrence. By analyzing available experimental catalogs, we show that the stochastic processes underlying these apparently different phenomena have universal properties. Namely, both problems exhibit the same distributions of sizes, interoccurrence times, and the same temporal clustering: We find after flare sequences with power law temporal correlations as the Omori law for seismic sequences. The observed universality suggests a common approach to the interpretation of both phenomena in terms of the same driving physical mechanism.

  7. 10 CFR 840.3 - Determination of extraordinary nuclear occurrence.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Determination of extraordinary nuclear occurrence. 840.3 Section 840.3 Energy DEPARTMENT OF ENERGY EXTRAORDINARY NUCLEAR OCCURRENCES § 840.3 Determination of extraordinary nuclear occurrence. If the DOE determines that both of the criteria set forth in § 840.4 and §...

  8. 10 CFR 840.3 - Determination of extraordinary nuclear occurrence.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Determination of extraordinary nuclear occurrence. 840.3 Section 840.3 Energy DEPARTMENT OF ENERGY EXTRAORDINARY NUCLEAR OCCURRENCES § 840.3 Determination of extraordinary nuclear occurrence. If the DOE determines that both of the criteria set forth in § 840.4 and §...

  9. 10 CFR 840.3 - Determination of extraordinary nuclear occurrence.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Determination of extraordinary nuclear occurrence. 840.3 Section 840.3 Energy DEPARTMENT OF ENERGY EXTRAORDINARY NUCLEAR OCCURRENCES § 840.3 Determination of extraordinary nuclear occurrence. If the DOE determines that both of the criteria set forth in § 840.4 and §...

  10. 10 CFR 840.3 - Determination of extraordinary nuclear occurrence.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Determination of extraordinary nuclear occurrence. 840.3 Section 840.3 Energy DEPARTMENT OF ENERGY EXTRAORDINARY NUCLEAR OCCURRENCES § 840.3 Determination of extraordinary nuclear occurrence. If the DOE determines that both of the criteria set forth in § 840.4 and §...

  11. 21 CFR 1002.20 - Reporting of accidental radiation occurrences.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Reporting of accidental radiation occurrences... SERVICES (CONTINUED) RADIOLOGICAL HEALTH RECORDS AND REPORTS Manufacturers' Reports on Accidental Radiation Occurrences § 1002.20 Reporting of accidental radiation occurrences. (a) Manufacturers of electronic...

  12. 21 CFR 1002.20 - Reporting of accidental radiation occurrences.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Reporting of accidental radiation occurrences... SERVICES (CONTINUED) RADIOLOGICAL HEALTH RECORDS AND REPORTS Manufacturers' Reports on Accidental Radiation Occurrences § 1002.20 Reporting of accidental radiation occurrences. (a) Manufacturers of electronic...

  13. 21 CFR 1002.20 - Reporting of accidental radiation occurrences.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Reporting of accidental radiation occurrences... SERVICES (CONTINUED) RADIOLOGICAL HEALTH RECORDS AND REPORTS Manufacturers' Reports on Accidental Radiation Occurrences § 1002.20 Reporting of accidental radiation occurrences. (a) Manufacturers of electronic...

  14. 21 CFR 1002.20 - Reporting of accidental radiation occurrences.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Reporting of accidental radiation occurrences... SERVICES (CONTINUED) RADIOLOGICAL HEALTH RECORDS AND REPORTS Manufacturers' Reports on Accidental Radiation Occurrences § 1002.20 Reporting of accidental radiation occurrences. (a) Manufacturers of electronic...

  15. 21 CFR 1002.20 - Reporting of accidental radiation occurrences.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Reporting of accidental radiation occurrences... SERVICES (CONTINUED) RADIOLOGICAL HEALTH RECORDS AND REPORTS Manufacturers' Reports on Accidental Radiation Occurrences § 1002.20 Reporting of accidental radiation occurrences. (a) Manufacturers of electronic...

  16. 10 CFR 840.3 - Determination of extraordinary nuclear occurrence.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Determination of extraordinary nuclear occurrence. 840.3 Section 840.3 Energy DEPARTMENT OF ENERGY EXTRAORDINARY NUCLEAR OCCURRENCES § 840.3 Determination of extraordinary nuclear occurrence. If the DOE determines that both of the criteria set forth in § 840.4 and §...

  17. Occurrence of potentially pathogenic arcobacters in shellfish.

    PubMed

    Mottola, Anna; Bonerba, Elisabetta; Figueras, Maria José; Pérez-Cataluña, Alba; Marchetti, Patrizia; Serraino, Andrea; Bozzo, Giancarlo; Terio, Valentina; Tantillo, Giuseppina; Di Pinto, Angela

    2016-08-01

    Considering that several recent cases of human gastroenteritis have been associated with species from the Arcobacter genus, and that few data are currently available about the occurrence of this genus in Italian shellfish, the aim of the present study was to evaluate the occurrence of Arcobacter spp. and the presence of virulence-associated genes. The approach consisted of cultural and biomolecular (multiplex-PCR and 16S-RFLP) methods identifying isolates, followed by PCR assays aimed at the cadF, ciaB, cjl349, irgA, hecA putative virulence genes. Arcobacter spp. was detected in 16/70 (22.8%) shellfish samples. Specifically, Arcobacter spp. was highlighted in 10/42 (23.8%) mussel and in 6/28 (21.4%) clam samples. Subsequently, biomolecular assays revealed Arcobacter butzleri in 12/16 (75%) and Arcobacter cryaerophilus 1B in 4/16 (25%) isolates. PCRs aimed at the five putative virulence genes demonstrated widespread distribution of these genes among Arcobacter isolates and some differences from the results published by other authors. Our research provides more information regarding the health risks associated with the consumption of raw bivalve molluscs and underlines the need to implement an adequate control plan by performing intensive and continuous monitoring in order to guarantee human health. PMID:27052698

  18. [Familial occurrence of botulism - a case report].

    PubMed

    AmbroŽová, Helena; DŽupová, Olga; Smíšková, Dita; Roháčová, Hana

    2014-06-01

    Botulism, a life-threatening condition, is very rare in the Czech Republic. Since 1960, a total of 155 cases have been reported; between 2010 and 2012, not a single case was identified. This is a case report of familiar occurrence of botulism following consumption of home-made pork and liver pâté in three family members admitted to the Department of Infectious, Tropical and Parasitic Diseases, Na Bulovce Hospital in Prague in May 2013. The neurological symptoms were dominated by diplopia and dysarthria. After administration of an antitoxin, all patients recovered. Given the poor availability of the antitoxin, a decision was made following this small family epidemic to have an emergency reserve of life-saving anti-infective drugs for the Czech Republic in the Toxicological Information Center in Prague.

  19. Rare Earth Element Mines, Deposits, and Occurrences

    USGS Publications Warehouse

    Orris, Greta J.; Grauch, Richard I.

    2002-01-01

    Data on rare earth (including yttrium) mines, deposits, and occurrences were compiled as part of an effort by the USGS and the University of Arizona Center for Mineral Resources to summarize current knowledge on the supply and demand outlook and related topics for this group of elements. Economic competition and environmental concerns are increasingly constraining the mining and processing of rare earths from the Mountain Pass mine in California. For many years, the deposit at Mountain Pass was the world's dominant source of rare earth elements and the United States was essentially self-sufficient. Starting approximately 10 years ago, the U.S. has become increasingly dependent (> 90 percent of separated rare earths) upon imports from China, now the dominant source of rare earths. A knowledge of the known economic and noneconomic sources of rare earths is basic to evaluating the outlook for rare earth supply and associated issues.

  20. Handbook of gas hydrate properties and occurrence

    SciTech Connect

    Kuustraa, V.A.; Hammershaimb, E.C.

    1983-12-01

    This handbook provides data on the resource potential of naturally occurring hydrates, the properties that are needed to evaluate their recovery, and their production potential. The first two chapters give data on the naturally occurring hydrate potential by reviewing published resource estimates and the known and inferred occurrences. The third and fourth chapters review the physical and thermodynamic properties of hydrates, respectively. The thermodynamic properties of hydrates that are discussed include dissociation energies and a simplified method to calculate them; phase diagrams for simple and multi-component gases; the thermal conductivity; and the kinetics of hydrate dissociation. The final chapter evaluates the net energy balance of recovering hydrates and shows that a substantial positive energy balance can theoretically be achieved. The Appendices of the Handbook summarize physical and thermodynamic properties of gases, liquids and solids that can be used in designing and evaluating recovery processes of hydrates. 158 references, 67 figures, 47 tables.

  1. Occurrence of minor elements in water

    USGS Publications Warehouse

    Durum, W.H.; Haffty, Joseph

    1961-01-01

    Three basic studies, using spectrographic methods, have been used to establish the occurrence of minor elements in natural waters. One study, of oceanborne chemicals in principal rivers, has established a method for the quantitative analysis of many minor elements. Strontium, barium, lithium, rubidium, chromium, nickel, copper, lead, boron, titanium, molybdenum, manganese, and vanadium occur most frequently in measurable quantities. Reconnaissance of the strontium in surface waters of the United States, shows that surface waters in parts of northern and western Texas and southern New Mexico and Arizona are comparatively high in strontium. A study of minor elements in selected waters of California is continuing. Assessment of preliminary data on uranium and radium in waters is facilitated by grouping data for 10 geotectonic regions of the United States.

  2. Tennis injuries: occurrence, aetiology, and prevention

    PubMed Central

    Pluim, B M; Staal, J B; Windler, G E; Jayanthi, N

    2006-01-01

    A systematic search of published reports was carried out in three electronic databases from 1966 on to identify relevant articles relating to tennis injuries. There were 39 case reports, 49 laboratory studies, 28 descriptive epidemiological studies, and three analytical epidemiological studies. The principal findings of the review were: first, there is a great variation in the reported incidence of tennis injuries; second, most injuries occur in the lower extremities, followed by the upper extremities and then the trunk; third, there have been very few longitudinal cohort studies that investigated the association between risk factors and the occurrence of tennis injuries (odds ratios, risk ratios, hazard ratios); and fourth, there were no randomised controlled trials investigating injury prevention measures in tennis. More methodologically sound studies are needed for a better understanding of risk factors, in order to design useful strategies to prevent tennis injuries. PMID:16632572

  3. Olmsted Syndrome: Rare Occurrence in Four Siblings

    PubMed Central

    Bukharia, Atishay; Komal, Sweta; Sudhanan, V Madhu; Chaudhary, Shyam Sundar

    2016-01-01

    Olmsted syndrome is a very rare and severe cicatrizing keratoderma associated with periorificial lesion. Most cases are sporadic but familial occurrence has been also seen. Till now around 73 cases have been reported and none of the reported cases have 4 siblings affected from this disease. We are reporting cases of 4 siblings of age 30 year female, 26 year female, 20 year male and 10 year male who were born to a third degree consangueinous marriage and presented with palmoplantar keratoderma, periorificial hyperkeratosis, flexion deformity, pseudoainhum and contracture of digits. There was no cardiac involvement. Hence, the diagnosis of Olmsted syndrome was made and all four patients were non responsive to treatment which included topical corticosteroid, topical salicylic acid, systemic isotretinoin, systemic acitretin and oral zinc in child. PMID:27293270

  4. Occurrence of transformation products in the environment

    USGS Publications Warehouse

    Kolpin, D.W.; Battaglin, W.A.; Conn, K.E.; Furlong, E.T.; Glassmeyer, S.T.; Kalkhoff, S.J.; Meyer, M.T.; Schnoebelen, D.J.; ,

    2009-01-01

    Historically, most environmental occurrence research has focused on the parent compounds of organic contaminants. Research, however, has documented that the environmental transport of chemicals, such as pesticides and emerging contaminants, are substantially underestimated if transformation products are not considered. Although most examples described herein were drawn from research conducted by the U.S. Geological Survey, such results are generally reflective of those found in other parts of the world. Results from a study of 51 streams in the Midwestern United States found that transformation products were seven of the ten most frequently detected pesticide compounds in late spring runoff (after application of pre-emergent herbicides), and nine of the ten most frequently detected compounds in fall season runoff (during and after harvest). In fact, 70% of the total herbicide concentration in water from the Mississippi River Basin was from transformation products. Results from a study of 86 municipal wells in Iowa found the frequency of detection increased from 17%, when pesticide parent compounds were considered, to 53%, when both parents and transformation products were considered. Transformation products were 12 of the 15 most frequently detected compounds for this groundwater study. Although studies on transformation products of synthetic organic compounds other than pesticides are not as common, wastewater treatment plant discharges have repeatedly been shown to contribute such transformation products to streams. In addition, select detergent transformation products have been commonly found in solid waste in the 1000's mg/kg. These findings and many others document that transformation products must be considered to fully assess the potential environmental occurrence of chemical contaminants and their transport and fate in various compartments of the hydrologic system. ?? 2008 Springer-Verlag Berlin Heidelberg.

  5. Fracture occurrence from radionuclides in the skeleton

    SciTech Connect

    Lloyd, R.D.; Taylor, G.N.; Miller, S.C.

    2000-06-01

    Because skeletal fractures were an important finding among persons contaminated with {sup 226}Ra, experience with fractures among dogs in the colony was summarized to determine the projected significance for persons contaminated with bone-seeking radionuclides. Comparison by Fisher's Exact Test of lifetime fracture occurrence in the skeletons of beagles injected as young adults suggested that for animals given {sup 226}Ra, {sup 228}Ra, {sup 228}Th, or {sup 239}Pu citrate, there was probably an excess over controls in fractures of the ribs, leg bones, spinous processes, and pelvis (os coxae) plus the mandible for dogs given {sup 226}Ra and the scapulae for dogs given {sup 228}Ra or 228 Th. Regression analysis indicated that significantly elevated fracture occurrence was especially notable at the higher radiation doses, at about 50 Gy average skeletal dose for {sup 239}Pu, 140 Gy for {sup 226}Ra, about 40 Gy for {sup 228}Ra, and more than 15 Gy for {sup 228}Th. The average number of fractures per dog was significantly elevated over that noted in controls for the highest radiation doses of {sup 239}Pu and {sup 226}Ra and for the higher doses of {sup 228}Ra and {sup 228}Th. For those dogs given {sup 90}Sr citrate, there was virtually no important difference from control beagles not given radionuclides, even at group mean cumulative skeletal radiation doses up to 101 Gy. Because of a large proportion of dogs with fractures that died with bone malignancy (even at dosage levels lower than those exhibiting an excess average number of fractures per dog), they conclude that fracture would not be an important endpoint at lower levels of plutonium contamination in humans such as would be expected to occur from occupational or environmental exposure.

  6. Association Between Benzodiazepine Use and Epilepsy Occurrence

    PubMed Central

    Harnod, Tomor; Wang, Yu-Chiao; Kao, Chia-Hung

    2015-01-01

    Abstract We conducted a retrospective case–control study to evaluate the association between the risk of benzodiazepine (BZD) use and epilepsy occurrence by using data from the Taiwan National Health Insurance Research Database. We recruited 1065 participants who ages 20 years or older and newly diagnosed with epilepsy (International Classification of Diseases, Ninth Revision, Clinical Modification 345) between 2004 and 2011 and assigned them to the epilepsy group. We subsequently frequency-matched them with participants in a control group (n = 4260) according to sex, age, and index year at a 1:4 ratio. A logistic regression model was employed to calculate the odds ratio (OR) for association of epilepsy with BZD exposure. Multivariate logistic regression was conducted to estimate the dose–response relationship between BZD levels and epilepsy risk. The adjusted OR (aOR) for the association of epilepsy with BZD exposure was 2.02 (95% confidence interval [CI] = 1.68–2.42). The aOR for an average BZD dose increased to 1.26 for the participants on <0.01 defined daily dose (DDD), and increased to 4.32 for those on ≥1.50 DDD. On average, when the DDD of BZD exposure increased by 100 units, the epilepsy risk increase by 1.03-fold (95% CI = 1.01–1.04, P = 0.003). The annual BZD exposure day ranges were significantly associated with epilepsy (2–7 days: aOR = 1.67; 8–35 days: aOR = 3.16; and ≥35 days: aOR = 5.60). Whenever the annual BZD exposure increased by 30 days, the risk of epilepsy notably increased by 1.03-fold (95% CI = 1.01–1.04, P < 0.001). In addition, users who quit BZD for more than 6 months still exhibited a higher risk of epilepsy than did the non-BZD users. A considerable increase in epilepsy occurrence was observed in ones with BZD use, particularly in those with prolonged use, multiple exposure, and high-dose consumption. PMID:26376408

  7. Earthquake Occurrence in Bangladesh and Surrounding Region

    NASA Astrophysics Data System (ADS)

    Al-Hussaini, T. M.; Al-Noman, M.

    2011-12-01

    The collision of the northward moving Indian plate with the Eurasian plate is the cause of frequent earthquakes in the region comprising Bangladesh and neighbouring India, Nepal and Myanmar. Historical records indicate that Bangladesh has been affected by five major earthquakes of magnitude greater than 7.0 (Richter scale) during 1869 to 1930. This paper presents some statistical observations of earthquake occurrence in fulfilment of a basic groundwork for seismic hazard assessment of this region. An up to date catalogue covering earthquake information in the region bounded within 17°-30°N and 84°-97°E for the period of historical period to 2010 is derived from various reputed international sources including ISC, IRIS, Indian sources and available publications. Careful scrutiny is done to remove duplicate or uncertain earthquake events. Earthquake magnitudes in the range of 1.8 to 8.1 have been obtained and relationships between different magnitude scales have been studied. Aftershocks are removed from the catalogue using magnitude dependent space window and time window. The main shock data are then analyzed to obtain completeness period for different magnitudes evaluating their temporal homogeneity. Spatial and temporal distribution of earthquakes, magnitude-depth histograms and other statistical analysis are performed to understand the distribution of seismic activity in this region.

  8. Aichi Virus 1: Environmental Occurrence and Behavior

    PubMed Central

    Kitajima, Masaaki; Gerba, Charles P.

    2015-01-01

    Aichi virus 1 (AiV-1), belonging to the genus Kobuvirus in the family Picornaviridae, has been proposed as a causative agent of human gastroenteritis potentially transmitted by fecal-oral routes through contaminated food or water. AiV-1 is globally distributed and has been detected in various types of environmental samples, such as sewage, river water, groundwater, and shellfish. Recent environmental studies revealed that this virus could be detected in higher frequency and greater abundance than other human enteric viruses. These findings suggest that AiV-1 could potentially be an appropriate indicator of viral contamination in the environment because of its high prevalence in water environments as well as structural and genetic similarity with some of the other important enteric viruses. Further studies on the occurrence and fate of AiV-1 in environments, even in combination with clinical studies of many regions, are needed for a better understanding of their epidemiology, temporal and geographical distribution, environmental stability, and potential health risks to humans. PMID:25996404

  9. A predictive geologic model of radon occurrence

    SciTech Connect

    Gregg, L.T. )

    1990-01-01

    Earlier work by LeGrand on predictive geologic models for radon focused on hydrogeologic aspects of radon transport from a given uranium/radium source in a fractured crystalline rock aquifer, and included submodels for bedrock lithology (uranium concentration), topographic slope, and water-table behavior and characteristics. LeGrand's basic geologic model has been modified and extended into a submodel for crystalline rocks (Blue Ridge and Piedmont Provinces) and a submodel for sedimentary rocks (Valley and Ridge and Coastal Plain Provinces). Each submodel assigns a ranking of 1 to 15 to the bedrock type, based on (a) known or supposed uranium/thorium content, (b) petrography/lithology, and (c) structural features such as faults, shear or breccia zones, diabase dikes, and jointing/fracturing. The bedrock ranking is coupled with a generalized soil/saprolite model which ranks soil/saprolite type and thickness from 1 to 10. A given site is thus assessed a ranking of 1 to 150 as a guide to its potential for high radon occurrence in the upper meter or so of soil. Field trials of the model are underway, comparing model predictions with measured soil-gas concentrations of radon.

  10. Parasomnias: co-occurrence and genetics.

    PubMed

    Hublin, C; Kaprio, J; Partinen, M; Koskenvu, M

    2001-06-01

    In clinical practice, parasomnias are often found to run in families and to co-occur. Several studies have indicated a role of genetic factors in them. In 1990, a questionnaire (response rate, 77%) sent to the Finnish Twin Cohort, a representative population sample aged 33-60 years, surveyed the frequency of five parasomnias (sleepwalking, sleeptalking, enuresis, bruxism, and nightmares) in childhood and as adults. In assessing the phenotypic covariation and shared genetic effects between the parasomnias, we used polychoric correlations and structural equation modelling. In childhood (n = 5856 individuals), co-occurrence is highest in sleeptalking with sleepwalking (R = 0.73), nightmares (R = 0.50), and bruxism (R = 0.43). As adults (n = 8567), the results are similar (R = 0.56, 0.43, and 0.39, respectively). The analyses of shared genetic effects included 815 monozygotic and 1442 dizygotic twin pairs with complete responses on four parasomnias as adults. The strongest genetic covariation was found in sleeptalking with sleepwalking, sleeptalking with bruxism, and in sleeptalking with nightmares. The estimated proportions of shared genetic effects were 50, 30, and 26%, respectively. The present results indicate that parasomnias share some common genetic background. PMID:11525419

  11. Musk xylene: analysis, occurrence, kinetics, and toxicology.

    PubMed

    Käfferlein, H U; Göen, T; Angerer, J

    1998-09-01

    1,3-Dimethyl-2,4,6-trinitro-5-tert.-butylbenzene (musk xylene, MX), a synthetic musk, is often used in fragrances and soaps to substitute the natural musk. MX belongs to the common group of nitromusk compounds. The main environmental intake of MX occurs after sewage introduction. The consumption of fish and drinking water as well as the use of body care and perfumed household products could lead to an ingestion of this substance in humans. Although the acute oral and dermal toxicity of MX is low, some hint for the carcinogenic potential of MX was found in one animal experiment. These findings and the high potential of MX as environmental contaminant, it is stable against biological and chemical degradation and it is highly lipophil, raised considerable attention in the field of environmental medicine. Biological monitoring and the toxicology of MX, which previously has been described to occur in human milk, human fat tissue, as well as human blood samples, are of central interest. The aim of this article is to summarize the data on the analysis, occurrence, kinetics, and toxicology of MX. As there is a lack of knowledge on human toxicity and human carcinogenicity of MX, a final evaluation of the toxicological data with regard to public health is still impossible. Nevertheless, in view of the published data about MX, there is no evidence for any substantial human risk at the moment.

  12. Occurrence, detection and detoxification of mycotoxins.

    PubMed

    Aiko, Visenuo; Mehta, Alka

    2015-12-01

    Mycotoxins have been identified as important toxins affecting animal species and humans ever since the discovery of aflatoxin B1 in 1960. Mycotoxigenic fungi are ubiquitous in nature and are held responsible for economic loss as they decrease crop yield and quality of food. The presence of fungi and their mycotoxins are reported not only in food grains but also in medicinal herbs and processed foods. Since prevention is not always possible, detoxification of mycotoxins have been attempted using several means; however, only few have been accepted for practical use, e.g. ammonia in the corn industry. Organizations such as the World Health Organization, US Food and Drug Administration and European Union have set regulations and safety limits of important mycotoxins, viz. aflatoxins, fusarium toxins, ochratoxin, patulin zearalenone, etc., to ensure the safety of the consumers. This review article is a brief and up-to-date account of the occurrence, detection and detoxification of mycotoxins for those interested in and considering research in this area.

  13. Widespread Natural Occurrence of Hydroxyurea in Animals.

    PubMed

    Fraser, David I; Liu, Kyle T; Reid, Bryan J; Hawkins, Emily; Sevier, Andrew; Pyle, Michelle; Robinson, Jacob W; Ouellette, Pierre H R; Ballantyne, James S

    2015-01-01

    Here we report the widespread natural occurrence of a known antibiotic and antineoplastic compound, hydroxyurea in animals from many taxonomic groups. Hydroxyurea occurs in all the organisms we have examined including invertebrates (molluscs and crustaceans), fishes from several major groups, amphibians and mammals. The species with highest concentrations was an elasmobranch (sharks, skates and rays), the little skate Leucoraja erinacea with levels up to 250 μM, high enough to have antiviral, antimicrobial and antineoplastic effects based on in vitro studies. Embryos of L. erinacea showed increasing levels of hydroxyurea with development, indicating the capacity for hydroxyurea synthesis. Certain tissues of other organisms (e.g. skin of the frog (64 μM), intestine of lobster (138 μM) gills of the surf clam (100 μM)) had levels high enough to have antiviral effects based on in vitro studies. Hydroxyurea is widely used clinically in the treatment of certain human cancers, sickle cell anemia, psoriasis, myeloproliferative diseases, and has been investigated as a potential treatment of HIV infection and its presence at high levels in tissues of elasmobranchs and other organisms suggests a novel mechanism for fighting disease that may explain the disease resistance of some groups. In light of the known production of nitric oxide from exogenously applied hydroxyurea, endogenous hydoxyurea may play a hitherto unknown role in nitric oxide dynamics.

  14. Foreshock occurrence rates before large earthquakes worldwide

    USGS Publications Warehouse

    Reasenberg, P.A.

    1999-01-01

    Global rates of foreshock occurrence involving shallow M ??? 6 and M ??? 7 mainshocks and M ??? 5 foreshocks were measured, using earthquakes listed in the Harvard CMT catalog for the period 1978-1996. These rates are similar to rates ones measured in previous worldwide and regional studies when they are normalized for the ranges of magnitude difference they each span. The observed worldwide rates were compared to a generic model of earthquake clustering, which is based on patterns of small and moderate aftershocks in California, and were found to exceed the California model by a factor of approximately 2. Significant differences in foreshock rate were found among subsets of earthquakes defined by their focal mechanism and tectonic region, with the rate before thrust events higher and the rate before strike-slip events lower than the worldwide average. Among the thrust events a large majority, composed of events located in shallow subduction zones, registered a high foreshock rate, while a minority, located in continental thrust belts, measured a low rate. These differences may explain why previous surveys have revealed low foreshock rates among thrust events in California (especially southern California), while the worldwide observations suggest the opposite: California, lacking an active subduction zone in most of its territory, and including a region of mountain-building thrusts in the south, reflects the low rate apparently typical for continental thrusts, while the worldwide observations, dominated by shallow subduction zone events, are foreshock-rich.

  15. Aichi virus 1: environmental occurrence and behavior.

    PubMed

    Kitajima, Masaaki; Gerba, Charles P

    2015-01-01

    Aichi virus 1 (AiV-1), belonging to the genus Kobuvirus in the family Picornaviridae, has been proposed as a causative agent of human gastroenteritis potentially transmitted by fecal-oral routes through contaminated food or water. AiV-1 is globally distributed and has been detected in various types of environmental samples, such as sewage, river water, groundwater, and shellfish. Recent environmental studies revealed that this virus could be detected in higher frequency and greater abundance than other human enteric viruses. These findings suggest that AiV-1 could potentially be an appropriate indicator of viral contamination in the environment because of its high prevalence in water environments as well as structural and genetic similarity with some of the other important enteric viruses. Further studies on the occurrence and fate of AiV-1 in environments, even in combination with clinical studies of many regions, are needed for a better understanding of their epidemiology, temporal and geographical distribution, environmental stability, and potential health risks to humans.

  16. Widespread Natural Occurrence of Hydroxyurea in Animals

    PubMed Central

    Fraser, David I.; Liu, Kyle T.; Reid, Bryan J.; Hawkins, Emily; Sevier, Andrew; Pyle, Michelle; Robinson, Jacob W.; Ouellette, Pierre H. R.; Ballantyne, James S.

    2015-01-01

    Here we report the widespread natural occurrence of a known antibiotic and antineoplastic compound, hydroxyurea in animals from many taxonomic groups. Hydroxyurea occurs in all the organisms we have examined including invertebrates (molluscs and crustaceans), fishes from several major groups, amphibians and mammals. The species with highest concentrations was an elasmobranch (sharks, skates and rays), the little skate Leucoraja erinacea with levels up to 250 μM, high enough to have antiviral, antimicrobial and antineoplastic effects based on in vitro studies. Embryos of L. erinacea showed increasing levels of hydroxyurea with development, indicating the capacity for hydroxyurea synthesis. Certain tissues of other organisms (e.g. skin of the frog (64 μM), intestine of lobster (138 μM) gills of the surf clam (100 μM)) had levels high enough to have antiviral effects based on in vitro studies. Hydroxyurea is widely used clinically in the treatment of certain human cancers, sickle cell anemia, psoriasis, myeloproliferative diseases, and has been investigated as a potential treatment of HIV infection and its presence at high levels in tissues of elasmobranchs and other organisms suggests a novel mechanism for fighting disease that may explain the disease resistance of some groups. In light of the known production of nitric oxide from exogenously applied hydroxyurea, endogenous hydoxyurea may play a hitherto unknown role in nitric oxide dynamics. PMID:26600157

  17. General Properties, Occurrence, and Preparation of Carbohydrates

    NASA Astrophysics Data System (ADS)

    Robyt, John F.

    D-Glucose and its derivatives and analogues, N-acetyl-D-glucosamine, N-acetyl-D-muramic acid, D-glucopyranosyl uronic acid, and D-glucitol represent 99.9% of the carbohydrates on the earth. D-Glucose is found in the free state in human blood and in the combined state in disaccharides, sucrose, lactose, and α,α-trehalose, in cyclic dextrins, and in polysaccharides, starch, glycogen, cellulose, dextrans; N-acetyl-D-glucosamine and an analogue N-acetyl-D-muramic acid are found in bacterial cell wall polysaccharide, murein, along with teichoic acids made up of poly-glycerol or -ribitol phosphodiesters. Other carbohydrates, D-mannose, D-mannuronic acid, D-galactose, N-acetyl-D-galactosamine, D-galacturonic acid, D-iduronic acid, L-guluronic acid, L-rhamnose, L-fucose, D-xylose, and N-acetyl-D-neuraminic acid are found in glycoproteins, hemicelluloses, glycosaminoglycans, and polysaccharides of plant exudates, bacterial capsules, alginates, and heparin. D-Ribofuranose-5-phosphate is found in many coenzymes and is the backbone of RNAs (ribonucleic acid), and 2-deoxy-D-ribofuranose-5-phosphate is the backbone of DNA (deoxyribonucleic acid). D-Fructofuranose is found in sucrose, inulin, and levan. The general properties and occurrence of these carbohydrates and general methods of isolation and preparation of carbohydrates are presented.

  18. Widespread Natural Occurrence of Hydroxyurea in Animals.

    PubMed

    Fraser, David I; Liu, Kyle T; Reid, Bryan J; Hawkins, Emily; Sevier, Andrew; Pyle, Michelle; Robinson, Jacob W; Ouellette, Pierre H R; Ballantyne, James S

    2015-01-01

    Here we report the widespread natural occurrence of a known antibiotic and antineoplastic compound, hydroxyurea in animals from many taxonomic groups. Hydroxyurea occurs in all the organisms we have examined including invertebrates (molluscs and crustaceans), fishes from several major groups, amphibians and mammals. The species with highest concentrations was an elasmobranch (sharks, skates and rays), the little skate Leucoraja erinacea with levels up to 250 μM, high enough to have antiviral, antimicrobial and antineoplastic effects based on in vitro studies. Embryos of L. erinacea showed increasing levels of hydroxyurea with development, indicating the capacity for hydroxyurea synthesis. Certain tissues of other organisms (e.g. skin of the frog (64 μM), intestine of lobster (138 μM) gills of the surf clam (100 μM)) had levels high enough to have antiviral effects based on in vitro studies. Hydroxyurea is widely used clinically in the treatment of certain human cancers, sickle cell anemia, psoriasis, myeloproliferative diseases, and has been investigated as a potential treatment of HIV infection and its presence at high levels in tissues of elasmobranchs and other organisms suggests a novel mechanism for fighting disease that may explain the disease resistance of some groups. In light of the known production of nitric oxide from exogenously applied hydroxyurea, endogenous hydoxyurea may play a hitherto unknown role in nitric oxide dynamics. PMID:26600157

  19. Occurrence of oral deformities in larval anurans

    USGS Publications Warehouse

    Drake, D.L.; Altig, R.; Grace, J.B.; Walls, S.C.

    2007-01-01

    We quantified deformities in the marginal papillae, tooth rows, and jaw sheaths of tadpoles from 13 population samples representing three families and 11 sites in the southeastern United States. Oral deformities were observed in all samples and in 13.5-98% of the specimens per sample. Batrachochytrium dendrobatidis (chytrid) infections were detected in three samples. There was high variability among samples in the pattern and number of discovered deformities. Pairwise associations between oral structures containing deformities were nonrandom for several populations, especially those with B. dendrobatidis infections or high total numbers of deformities. Comparisons of deformities among samples using multivariate analyses revealed that tadpole samples grouped together by family. Analyses of ordination indicated that three variables, the number of deformities, the number of significant associations among deformity types within populations, and whether populations were infected with B. dendrobatidis, were significantly correlated with the pattern of deformities. Our data indicate that the incidence of oral deformities can be high in natural populations and that phylogeny and B. dendrobatidis infection exert a strong influence on the occurrence and type of oral deformities in tadpoles. ?? by the American Society of Ichthyologists and Herperologists.

  20. Occurrence of Streptococcus macedonicus in Italian cheeses.

    PubMed

    Pacini, Federico; Cariolato, Diego; Andrighetto, Christian; Lombardi, Angiolella

    2006-08-01

    A new approach for the detection and enumeration of Streptococcus macedonicus in cheese was developed. The method which is based on a first screening of cheeses by a PCR assay specific for S. macedonicus followed by plating positive samples on a differential medium (SM medium) was applied to 51 samples derived from PDO and traditional Italian cheeses. Streptococcus macedonicus was found in 16 of the 51 samples examined in the present work. With the exclusion of an Asiago cheese sample in which very high numbers of S. macedonicus (7.13 log CFU g(-1)) were found, the counts of S. macedonicus in SM medium ranged from 2.48 to 4.70 log CFU g(-1). In the same cheeses, total streptococci enumerated onto M17 agar were found at higher concentrations with values up to 7.88 log CFU g(-1). The system developed was particularly useful for the differential count of S. macedonicus in cheese and allowed to evaluate the occurrence of this species within the complex microbial lactic acid bacteria (LAB) population, which is typical of traditional cheeses. Results showed that in the examined cheeses S. macedonicus cannot be considered as a dominant LAB species.

  1. Occurrence, uses, and carcinogenicity of arylamines.

    PubMed

    Chung, King-Thom

    2015-01-01

    Arylamines are chemically synthesized and contained in oxidants, epoxy polymers, explosives, fungicides, pesticides, colorants, polyurethanes, and used in rubber, pharmacology, cosmetics, and other chemical industries. Many arylamines are ubiquitously present in cigarette smoke, cooking fume hoods, foods, automobile exhaust, industrial sites, etc. Some arylamines can be generated through azo reduction by intestinal, skin, and environmental microorganisms from azo dyes that are widely used. Arylamines can also be generated by reduction of the nitro-group containing polyhydrated hydrocarbons including muntions. Some arylamines are released by burning nitrogen containing organic materials at high temperatures. Some medical drugs are also arylamines. Furthermore, many arylamines are essential constituents of normal metabolism or the result of abnormal metabolism or dietary sources. Some arylamines are mutagenic, carcinogenic or the cause of other kinds of maladies. Some arylamine are considered the major etiological agents of bladder tumors in humans and animals but may also induce other types of cancers in various organs. The organ, tissue, and species specificity of the arylamine-inducing carcinogenesis may be determined by their availability, distribution, and the presence of metabolic activation/detoxicification enzymes of each organ or tissue of different species. The ubiquitous arylamines, therefore, pose serious hazards to human health and environment. This article will address the occurrence, uses, carcinogenicity, and other arylamines-induced diseases.

  2. Occurrence of foodborne bacteria in Alberta feedlots.

    PubMed

    Van Donkersgoed, Joyce; Bohaychuk, Valerie; Besser, Thomas; Song, Xin-Ming; Wagner, Bruce; Hancock, Dale; Renter, David; Dargatz, David

    2009-02-01

    The occurrence of generic Escherichia coli, E. coli O157, Salmonella, and Campylobacter in cattle manure, beef carcasses, catch basin water, and soils receiving manure application was determined in 21 Alberta feedlots. In cattle manure, generic E. coli (98%, 2069/2100) and Campylobacter (76%, 1590/2100) were frequently detected; E. coli O157 (7%, 143/2100) and Salmonella (1%, 20/2100) were less frequently detected. Samples from beef carcasses in the cooler following Hazard Analysis Critical Control Point interventions yielded only 1 isolate each of generic E. coli and Campylobacter (1/1653) and no Salmonella (0/1653). Catch basin water specimens were positive for generic E. coli in both the spring (62%, 13/21) and the fall (52%, 11/21). Other bacteria were detected only in the spring water specimens, including E. coli O157 (29%, 6/21), Salmonella (5%, 1/21), and Campylobacter (52%, 11/21). Generic E. coli was frequently isolated from soil specimens (30%, 27/88), but E. coli O157 was not found in soil samples obtained in the spring and was only occasionally detected in the fall samples (9%, 3/32). Salmonella were occasionally found in the soil specimens collected in the spring (3%, 2/56), but not in the fall season (0/32). Campylobacter jejuni was frequent in cattle manure (66%, 1070/1623), but rare in carcass and environmental samples. E. coli O157 and Salmonella were rarely detected in cattle or the environment. Generic E. coli and Salmonella were rarely detected on carcasses.

  3. Comprehensive Flux Occurrence Statistics at Geosynchronous Orbit

    NASA Astrophysics Data System (ADS)

    Thomsen, M. F.; Denton, M. H.; Bodeau, M.

    2005-12-01

    Geosynchronous orbit, the distance at which the orbital period around the Earth is 24 hours, is home to more than 200 satellites. From a space weather perspective, the environment in this orbit is highly variable and far from benign. Satellites exposed to these harsh conditions are subject to episodes of deep dielectric charging, surface charging, solar panel degradation, single event upsets, radiation degradation of optical coatings and paints, and other deleterious effects. Either suddenly or gradually over time, such effects can cause catastrophic or simply lifetime-shortening consequences for satellite systems. To protect against these environmental effects, spacecraft designers need to know quantitatively what the nature of the environment is likely to be over the design lifetime of their satellites. In recent years a number of such statistical analyses have been conducted, demonstrating the systematic dependence of geosynchronous plasma properties on orbital position, geomagnetic activity, and phase of the solar cycle. These studies have helped illuminate the physical processes that govern the nature of the plasma at geosynchronous orbit, but they do not provide a condensed description of the environment that is suitable for use by spacecraft designers. We report here a definitive statistical characterization of the geosynchronous environment that will be more useful for such purposes. The analysis is based on the LANL MPA geosynchronous plasma dataset, which now comprises more than 70 satellite-years of measurements extending well over a full solar cycle. We present the flux occurrence statistics of ions and electrons with energies in the range from ~1 eV to ~45 keV, covering the populations that are responsible for satellite surface charging and radiation damage to surface materials, and that provide the source for the higher-energy ring current and radiation belts. Significant differences have been found in long-term averages compared to the AE-8, AP-8

  4. Arsenic occurrence in Brazil and human exposure.

    PubMed

    de Figueiredo, Bernardino Ribeiro; Borba, Ricardo Perobelli; Angélica, Rômulo Simões

    2007-04-01

    Environmental exposure to arsenic (As) in terms of public health is receiving increasing attention worldwide following cases of mass contamination in different parts of the world. However, there is a scarcity of data available on As geochemistry in Brazilian territory, despite the known occurrence of As in some of the more severely polluted areas of Brazil. The purpose of this paper is to discuss existing data on As distribution in Brazil based on recent investigations in three contaminated areas as well as results from the literature. To date, integrated studies on environmental and anthropogenic sources of As contamination have been carried out only in three areas in Brazil: (1) the Southeastern region, known as the Iron Quadrangle, where As was released into the drainage systems, soils and atmosphere as a result of gold mining; (2) the Ribeira Valley, where As occurs in Pb-Zn mine wastes and naturally in As-rich rocks and soils; (3) the Amazon region, including the Santana area, where As is associated with manganese ores mined over the last 50 years. Toxicological studies revealed that the populations were not exposed to elevated levels of As, with the As concentrations in surface water in these areas rarely exceeding 10 microg/L. Deep weathering of bedrocks along with formation of Fe/Al-enriched soils and sediments function as a chemical barrier that prevents the release of As into the water. In addition, the tropical climate results in high rates of precipitation in the northern and southeastern regions and, hence, the As contents of drinking water is diluted. Severe cases of human As exposure related to non-point pollution sources have not been reported in Brazil. However, increasing awareness of the adverse health effects of As will eventually lead to a more complete picture of the distribution of As in Brazil. PMID:17351814

  5. Arsenic occurrence in Brazil and human exposure.

    PubMed

    de Figueiredo, Bernardino Ribeiro; Borba, Ricardo Perobelli; Angélica, Rômulo Simões

    2007-04-01

    Environmental exposure to arsenic (As) in terms of public health is receiving increasing attention worldwide following cases of mass contamination in different parts of the world. However, there is a scarcity of data available on As geochemistry in Brazilian territory, despite the known occurrence of As in some of the more severely polluted areas of Brazil. The purpose of this paper is to discuss existing data on As distribution in Brazil based on recent investigations in three contaminated areas as well as results from the literature. To date, integrated studies on environmental and anthropogenic sources of As contamination have been carried out only in three areas in Brazil: (1) the Southeastern region, known as the Iron Quadrangle, where As was released into the drainage systems, soils and atmosphere as a result of gold mining; (2) the Ribeira Valley, where As occurs in Pb-Zn mine wastes and naturally in As-rich rocks and soils; (3) the Amazon region, including the Santana area, where As is associated with manganese ores mined over the last 50 years. Toxicological studies revealed that the populations were not exposed to elevated levels of As, with the As concentrations in surface water in these areas rarely exceeding 10 microg/L. Deep weathering of bedrocks along with formation of Fe/Al-enriched soils and sediments function as a chemical barrier that prevents the release of As into the water. In addition, the tropical climate results in high rates of precipitation in the northern and southeastern regions and, hence, the As contents of drinking water is diluted. Severe cases of human As exposure related to non-point pollution sources have not been reported in Brazil. However, increasing awareness of the adverse health effects of As will eventually lead to a more complete picture of the distribution of As in Brazil.

  6. DON occurrence in cereal grains: A North American perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The occurrence of deoxynivalenol (DON) in agricultural commodities has been reported all over the world, with levels varying amongst grain type and years of production. However, a systematic review of the current situation regarding this mycotoxin, its occurrence, and its management in North America...

  7. 10 CFR 140.83 - Determination of extraordinary nuclear occurrence.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Determination of extraordinary nuclear occurrence. 140.83 Section 140.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) FINANCIAL PROTECTION REQUIREMENTS AND INDEMNITY AGREEMENTS Extraordinary Nuclear Occurrences § 140.83 Determination of extraordinary...

  8. 10 CFR 140.83 - Determination of extraordinary nuclear occurrence.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Determination of extraordinary nuclear occurrence. 140.83 Section 140.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) FINANCIAL PROTECTION REQUIREMENTS AND INDEMNITY AGREEMENTS Extraordinary Nuclear Occurrences § 140.83 Determination of extraordinary...

  9. 10 CFR 140.83 - Determination of extraordinary nuclear occurrence.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Determination of extraordinary nuclear occurrence. 140.83 Section 140.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) FINANCIAL PROTECTION REQUIREMENTS AND INDEMNITY AGREEMENTS Extraordinary Nuclear Occurrences § 140.83 Determination of extraordinary...

  10. 10 CFR 140.83 - Determination of extraordinary nuclear occurrence.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Determination of extraordinary nuclear occurrence. 140.83 Section 140.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) FINANCIAL PROTECTION REQUIREMENTS AND INDEMNITY AGREEMENTS Extraordinary Nuclear Occurrences § 140.83 Determination of extraordinary...

  11. 10 CFR 140.83 - Determination of extraordinary nuclear occurrence.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Determination of extraordinary nuclear occurrence. 140.83 Section 140.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) FINANCIAL PROTECTION REQUIREMENTS AND INDEMNITY AGREEMENTS Extraordinary Nuclear Occurrences § 140.83 Determination of extraordinary...

  12. Archway for Radiation and Micrometeorite Occurrence Resistance

    NASA Technical Reports Server (NTRS)

    Giersch, Louis R.

    2012-01-01

    The environmental conditions of the Moon require mitigation if a long-term human presence is to be achieved for extended periods of time. Radiation, micrometeoroid impacts, high-velocity debris, and thermal cycling represent threats to crew, equipment, and facilities. For decades, local regolith has been suggested as a candidate material to use in the construction of protective barriers. A thickness of roughly 3m is sufficient protection from both direct and secondary radiation from cosmic rays and solar protons; this thickness is sufficient to reduce radiation exposure even during solar flares. NASA has previously identified a need for innovations that will support lunar habitats using lightweight structures because the reduction of structural mass translates directly into additional up and down mass capability that would facilitate additional logistics capacity and increased science return for all mission phases. The development of non-pressurized primary structures that have synergy with the development of pressurized structures is also of interest. The use of indigenous or in situ materials is also a well-known and active area of research that could drastically improve the practicality of human exploration beyond low-Earth orbit. The Archway for Radiation and Micrometeorite Occurrence Resistance (ARMOR) concept is a new, multifunctional structure that acts as radiation shielding and micrometeorite impact shielding for long-duration lunar surface protection of humans and equipment. ARMOR uses a combination of native regolith and a deployed membrane jacket to yield a multifunctional structure. ARMOR is a robust and modular system that can be autonomously assembled on-site prior to the first human surface arrival. The system provides protection by holding a sufficiently thick (3 m) archshaped shell of local regolith around a central cavity. The regolith is held in shape by an arch-shaped jacket made of strong but deployable material. No regolith processing is

  13. THE OCCURRENCE OF DISINFECTION BY-PRODUCTS OF HEALTH CONCERN IN DRINKING WATER: RESULTS OF A NATIONWIDE DBP OCCURRENCE STUDY

    EPA Science Inventory

    The motivation for this Nationwide Disinfection By-product (DBP) Occurrence Study was two-fold: First, more than 500 DBPs have been reported in the literature, yet there is almost no quantitative occurrence information for most. As a result, there is significant uncertainty ove...

  14. Global database of leishmaniasis occurrence locations, 1960-2012.

    PubMed

    Pigott, David M; Golding, Nick; Messina, Jane P; Battle, Katherine E; Duda, Kirsten A; Balard, Yves; Bastien, Patrick; Pratlong, Francine; Brownstein, John S; Freifeld, Clark C; Mekaru, Sumiko R; Madoff, Lawrence C; George, Dylan B; Myers, Monica F; Hay, Simon I

    2014-01-01

    The leishmaniases are neglected tropical diseases of significant public health importance. However, information on their global occurrence is disparate and sparse. This database represents an attempt to collate reported leishmaniasis occurrences from 1960 to 2012. Methodology for the collection of data from the literature, abstraction of case locations and data processing procedures are described here. In addition, strain archives and online data resources were accessed. A total of 12,563 spatially and temporally unique occurrences of both cutaneous and visceral leishmaniasis comprise the database, ranging in geographic scale from villages to states. These data can be used for a variety of mapping and spatial analyses covering multiple resolutions.

  15. A global compendium of human dengue virus occurrence.

    PubMed

    Messina, Jane P; Brady, Oliver J; Pigott, David M; Brownstein, John S; Hoen, Anne G; Hay, Simon I

    2014-01-01

    A global geographic database of human dengue virus occurrence was produced to generate a global risk map and associated burden estimates(1). Herein we present the database, which comprises occurrence data linked to point or polygon locations, derived from peer-reviewed literature and case reports as well as informal online sources. Entries date from 1960 to 2012. We describe all data collection processes in full, as well as geo-positioning, database management and quality-control procedures. This is the most comprehensive database of confirmed human dengue infection to-date, consisting of 8,309 geo-positioned occurrences in total.

  16. The global compendium of Aedes aegypti and Ae. albopictus occurrence.

    PubMed

    Kraemer, Moritz U G; Sinka, Marianne E; Duda, Kirsten A; Mylne, Adrian; Shearer, Freya M; Brady, Oliver J; Messina, Jane P; Barker, Christopher M; Moore, Chester G; Carvalho, Roberta G; Coelho, Giovanini E; Van Bortel, Wim; Hendrickx, Guy; Schaffner, Francis; Wint, G R William; Elyazar, Iqbal R F; Teng, Hwa-Jen; Hay, Simon I

    2015-01-01

    Aedes aegypti and Ae. albopictus are the main vectors transmitting dengue and chikungunya viruses. Despite being pathogens of global public health importance, knowledge of their vectors' global distribution remains patchy and sparse. A global geographic database of known occurrences of Ae. aegypti and Ae. albopictus between 1960 and 2014 was compiled. Herein we present the database, which comprises occurrence data linked to point or polygon locations, derived from peer-reviewed literature and unpublished studies including national entomological surveys and expert networks. We describe all data collection processes, as well as geo-positioning methods, database management and quality-control procedures. This is the first comprehensive global database of Ae. aegypti and Ae. albopictus occurrence, consisting of 19,930 and 22,137 geo-positioned occurrence records respectively. Both datasets can be used for a variety of mapping and spatial analyses of the vectors and, by inference, the diseases they transmit.

  17. Occurrence of Rock Varnish at Yungay, Atacama Desert, Chile

    NASA Astrophysics Data System (ADS)

    Kuhlman, K. R.; McKay, C. P.

    2007-03-01

    Rock varnish is a thin nanostratigraphic coating consisting of clay particles cemented together by Fe and Mn oxides and is ubiquitous in arid climates. We report the occurrence of rock varnish in the Mars-like conditions present at Yungay.

  18. Lunar phases and seizure occurrence: just an ancient legend?

    PubMed

    Polychronopoulos, P; Argyriou, A A; Sirrou, V; Huliara, V; Aplada, M; Gourzis, P; Economou, A; Terzis, E; Chroni, E

    2006-05-01

    The authors retrospectively reviewed all neurologic records of an emergency unit from 1999 to 2003 to identify a potential association between lunar phases and seizure occurrence. Overall 859 patients admitted for seizure occurrence were divided into the four quarters of the synodic month according to moon phases. A significant clustering of seizures around the full moon period was observed, supporting the ancient belief of periodic increased seizure frequency during full-moon days.

  19. Emerging Pollutants - Part I: Occurrence, Fate and Transport.

    PubMed

    Qiu, Lang; Dong, Zhanfeng; Sun, Huan; Li, Hongxiang; Chang, Chein-Chi

    2016-10-01

    Part I: Occurrence, Fate, and Transport (this review) is a sequel of Emerging Pollutants. This review compiles research in 2015 for investigating emerging pollutants in wastewater and environmental sources of emerging pollutants. It investigates the occurrence, fate, transport of emerging pollutants in the environment. This review further discusses the monitoring approaches, modeling, and toxicological impacts of these compounds that are relevant to wastewater. PMID:27620111

  20. Statistics of ionospheric scintillation occurrence over European high latitudes

    NASA Astrophysics Data System (ADS)

    Sreeja, V.; Aquino, M.

    2014-12-01

    Rapid fluctuation in the amplitude and phase of transionospheric radio signals caused by small scale ionospheric plasma density irregularities is known as scintillation. Over the high latitudes, irregularities causing scintillation are associated with large scale plasma structures and scintillation occurrence is mainly enhanced during geomagnetic storms. This paper presents a statistical analysis of scintillation occurrence on GPS L1C/A signal at a high latitude station located in Bronnoysund (geographic latitude 65.5°N, geographic longitude 12.2°E; corrected geomagnetic (CGM) latitude 62.77°N), Norway, during the periods around the peaks of solar cycles 23 (2002-2003) and 24 (2011-2013). The analysis revealed that the scintillation occurrence at Bronnoysund during both the solar maximum periods maximises close to the midnight magnetic local time (MLT) sector. A higher occurrence of scintillation is observed on geomagnetically active days during both the solar maximum periods. The seasonal pattern of scintillation occurrence indicated peaks during the summer and equinoctial months. A comparison with the interplanetary magnetic field (IMF) components By and Bz showed an association of scintillation occurrence with the southward IMF Bz conditions.

  1. Sinkhole occurrence in consequence of heavy rainstorms

    NASA Astrophysics Data System (ADS)

    Parise, Mario; Pisano, Luca; Vennari, Carmela

    2016-04-01

    hazards. References Ford, D.C. & Williams P.W. (2007). Karst geomorphology and hydrology. 2nd ed. John Wiley & Sons, Chichester, U.K. Gutierrez, F., J. Guerrero J. & Lucha P. (2008) A genetic classification of sinkholes illustrated from evaporite paleo-karst exposures in Spain. Environmental Geology, 53, 993-1006. Gutierrez F., Parise M., De Waele J. & Jourde H. (2014) A review on natural and human-induced geohazards and impacts in karst. Earth-Science Reviews, 138, 61-88. Martinotti M.E., Pisano L., Trabace M., Marchesini I., Peruccacci S., Rossi M., Amoruso G., Loiacono P., Vennari C., Vessia G., Parise M. & Brunetti M. (2015) Extreme rainfall events in karst environments: the case study of September 2014 in the Gargano area (southern Italy). Geophysical Research Abstracts, 17, 2683. Parise M. (2008) Rock failures in karst. In: Cheng Z., Zhang J., Li Z., Wu F. & Ho K. (Eds.), Landslides and Engineered Slopes. Proc. 10th International Symposium on Landslides, Xi'an (China), June 30 - July 4, 2008, 1, 275-280. Parise M. (2012) A present risk from past activities: sinkhole occurrence above underground quarries. Carbonates and Evaporites, 27 (2), 109-118. Parise M. (2015a) A procedure for evaluating the susceptibility to natural and anthropogenic sinkholes. Georisk, 9 (4), 272-285. Parise M. (2015b) Karst geo-hazards: causal factors, human actions, and management issues. Acta Carsologica, 44 (2). Parise M. & Vennari C. (2013) A chronological catalogue of sinkholes in Italy: the first step toward a real evaluation of the sinkhole hazard. In: Land L., Doctor D.H. & Stephenson B. (Eds.), Proceedings of the 13th Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst, Carlsbad (New Mexico, USA), 6-10 May 2013, National Cave and Karst Research Institute, 383-392. Parise M., Ravbar N., Živanovic V., Mikszewski A., Kresic N., Madl-Szonyi J. & Kukuric N. (2015) Hazards in Karst and Managing Water Resources Quality. Chapter 17 in: Z

  2. Evolution and palaeoenvironment of the Bauru Basin (Upper Cretaceous, Brazil)

    NASA Astrophysics Data System (ADS)

    Fernandes, Luiz Alberto; Magalhães Ribeiro, Claudia Maria

    2015-08-01

    The Bauru Basin was one of the great Cretaceous desert basins of the world, evolved in arid zone called Southern Hot Arid Belt. Its paleobiological record consists mainly of dinosaurs, crocodiles and turtles. The Bauru Basin is an extensive region of the South American continent that includes parts of the southeast and south of Brazil, covering an area of 370,000 km2. It is an interior continental basin that developed as a result of subsidence of the central-southern part of the South-American Platform during the Late Cretaceous (Coniacian-Maastrichtian). This sag basin is filled by a sandy siliciclastic sequence with a preserved maximum thickness of 480 m, deposited in semiarid to desert conditions. Its basement consists of volcanic rocks (mainly basalts) of the Lower Cretaceous (Hauterivian) Serra Geral basalt flows, of the Paraná-Etendeka Continental Flood Basalt Province. The sag basin was filled by an essentially siliciclastic psammitic sequence. In lithostratigraphic terms the sequence consists of the Caiuá and Bauru groups. The northern and northeastern edges of the basin provide a record of more proximal original deposits, such as associations of conglomeratic sand facies from alluvial fans, lakes, and intertwined distributary river systems. The progressive basin filling led to the burial of the basaltic substrate by extensive blanket sand sheets, associated with deposits of small dunes and small shallow lakes that retained mud (such as loess). Also in this intermediate context between the edges (more humid) and the interior (dry), wide sand sheet areas crossed by unconfined desert rivers (wadis) occurred. In the central axis of the elliptical basin a regional drainage system formed, flowing from northeast to southwest between the edges of the basin and the hot and dry inner periphery of the Caiuá desert (southwest). Life in the Bauru Basin flourished most in the areas with the greatest water availability, in which dinosaurs, crocodiles, turtles, fish, amphibians, molluscs, crustaceans, and charophyte algae lived. The fossil record mainly consists of transported bones and other skeletal fragments. In the northeastern and eastern marginal regions fossils are found in marginal alluvial fan deposits, broad plains of braided streams and ephemeral alkaline water lakes. In the basin interior the fossil record is related to deposits in sand sheets with braided streams, small dunes, and shallow lakes. In the great Caiuá inner desert a few smaller animals could survive (small reptiles and early mammals), sometimes leaving their footprints in dune foreset deposits. The aim of this article is to present and link the basin sedimentary evolution, palaeoecological features and palaeontological record.

  3. Maastrichtian sedimentation and palaeoenvironments of the Saratov Volga region

    NASA Astrophysics Data System (ADS)

    Iakovishina, Elena; Blinova, Irina; Kopaevich, Ludmila; Vishnevskaya, Valentina; Bordunov, Sergey

    2016-04-01

    The Saratov Volga region was a shallow-marine epicontinental basin North-Eastern shelf zone of the Tethys Ocean in the Maastrichtian. The basis for the modeling conditions of sedimentation was the detection mineral composition of rocks, as well as the contents of various chemical elements in rocks in three reference sections: Lower Bannovka, quarries "Bolshevik" and "Kommunar". Rocks of quarries "Bolshevik" and "Kommunar" characterized by quartz-calcite mineral association. The main rock-forming mineral is calcite, small amounts in rocks contain quartz. Other mineral composition characterized section Lower Bannovka. At the base of the section in the rock marked the presence of the opal. The source of silica are radiolarians. Favorable conditions for the existence of which is cold deep water enriched with SiO2. Above the section marked authigenic glauconite, which are confined to zones of skip in sedimentation.Further up begins to dominate the accumulation of calcite with rich bentic foraminifera. Clay minerals in rocks of the section Lower Bannovka presented montmorillonite and illite. The relationship of chemical elements and their alkali modules allow to detail the conditions of sedimentation. The ratio of Fe/Mn in them varies from 44 to 5729. Higher values are characteristic of glauconite sandstones. Up the section marked decrease in the Ti/Zr, indicating that the increase in the distance from the source area to the place of deposition. The similarity values of the ratio Ti/Zr samples indicates a community source area. Sedimentation Model revealed the impact of the PreUral strait connecting Tethys and Paleoarktic. Through the Strait of deep cold water saturated with SiO2, penetrated into the of the Saratov Volga region, were accumulated clay. The closing of the PreUral Strait changed the conditions of sedimentation, the associated fall in sea levels due to global cooling reflected in the crisis of radiolarians, increase in the number of glauconite. Subsequent warming and warm-water transgression caused dominance of carbonates. The work was supported by grants 15-05-04990, 15-05-04700 Russian Foundation for Basic Research and IGCP project 609.

  4. Late Pleistocene Palaeoenvironments of the Southern Lake Agassiz Basin, USA

    NASA Astrophysics Data System (ADS)

    Yansa, Catherine H.; Ashworth, Allan C.

    2005-03-01

    Macroscopic plant remains, pollen, insect and mollusc fossils recovered from a cut bank on the Red River in North Dakota, USA, provide evidence that an extensive wetland occupied the southern basin of Lake Agassiz from 10 230 to 9900 14C yr BP. Marsh-dwelling plants and invertebrates had colonised the surface of a prograding delta during the low-water Moorhead Phase of Lake Agassiz. A species of Salix (willow) was abundant along distributary channels, and stands of Populus tremuloides (aspen), Ulmus sp. (elm), Betula sp. (birch), and Picea sp. (spruce) grew on the better-drained sand bars and beach ridges. Most of the species of plants, insects, and molluscs represented as fossils are within their existing geographic ranges. Based on a few species with more northerly distributions, mean summer temperature may have been about 1-2°C lower than the present day. No change in species composition occurred in the transition from the Younger Dryas to Preboreal. At the time that the wetland existed, Lake Agassiz was draining either eastward to the North Atlantic Ocean or northwestward to the Arctic Ocean. The wetland was drowned during the Emerson Phase transgression that resulted in meltwater draining southward to the Gulf of Mexico after 9900 14C yr BP.

  5. Terrestrial Planet Occurrence Rates for the Kepler GK Dwarf Sample

    NASA Astrophysics Data System (ADS)

    Burke, Christopher J.; Christiansen, Jessie L.; Mullally, F.; Seader, Shawn; Huber, Daniel; Rowe, Jason F.; Coughlin, Jeffrey L.; Thompson, Susan E.; Catanzarite, Joseph; Clarke, Bruce D.; Morton, Timothy D.; Caldwell, Douglas A.; Bryson, Stephen T.; Haas, Michael R.; Batalha, Natalie M.; Jenkins, Jon M.; Tenenbaum, Peter; Twicken, Joseph D.; Li, Jie; Quintana, Elisa; Barclay, Thomas; Henze, Christopher E.; Borucki, William J.; Howell, Steve B.; Still, Martin

    2015-08-01

    We measure planet occurrence rates using the planet candidates discovered by the Q1-Q16 Kepler pipeline search. This study examines planet occurrence rates for the Kepler GK dwarf target sample for planet radii, 0.75 ≤slant {R}{{p}} ≤slant 2.5 {R}\\oplus , and orbital periods, 50 ≤slant {P}{orb} ≤slant 300 days, with an emphasis on a thorough exploration and identification of the most important sources of systematic uncertainties. Integrating over this parameter space, we measure an occurrence rate of F0 = 0.77 planets per star, with an allowed range of 0.3≤slant {F}0 ≤slant 1.9. The allowed range takes into account both statistical and systematic uncertainties, and values of F0 beyond the allowed range are significantly in disagreement with our analysis. We generally find higher planet occurrence rates and a steeper increase in planet occurrence rates toward small planets than previous studies of the Kepler GK dwarf sample. Through extrapolation, we find that the one year orbital period terrestrial planet occurrence rate {\\zeta }1.0 = 0.1, with an allowed range of 0.01≤slant {\\zeta }1.0 ≤slant 2, where {\\zeta }1.0 is defined as the number of planets per star within 20% of the {R}{{p}} and {P}{orb} of Earth. For G dwarf hosts, the {\\zeta }1.0 parameter space is a subset of the larger {η }\\oplus parameter space, thus {\\zeta }1.0 places a lower limit on {η }\\oplus for G dwarf hosts. From our analysis, we identify the leading sources of systematics impacting Kepler occurrence rate determinations as reliability of the planet candidate sample, planet radii, pipeline completeness, and stellar parameters.

  6. Does probability of occurrence relate to population dynamics?

    PubMed Central

    Thuiller, Wilfried; Münkemüller, Tamara; Schiffers, Katja H.; Georges, Damien; Dullinger, Stefan; Eckhart, Vincent M.; Edwards, Thomas C.; Gravel, Dominique; Kunstler, Georges; Merow, Cory; Moore, Kara; Piedallu, Christian; Vissault, Steve; Zimmermann, Niklaus E.; Zurell, Damaris; Schurr, Frank M.

    2014-01-01

    Hutchinson defined species’ realized niche as the set of environmental conditions in which populations can persist in the presence of competitors. In terms of demography, the realized niche corresponds to the environments where the intrinsic growth rate (r) of populations is positive. Observed species occurrences should reflect the realized niche when additional processes like dispersal and local extinction lags do not have overwhelming effects. Despite the foundational nature of these ideas, quantitative assessments of the relationship between range-wide demographic performance and occurrence probability have not been made. This assessment is needed both to improve our conceptual understanding of species’ niches and ranges and to develop reliable mechanistic models of species geographic distributions that incorporate demography and species interactions. The objective of this study is to analyse how demographic parameters (intrinsic growth rate r and carrying capacity K) and population density (N) relate to occurrence probability (Pocc). We hypothesized that these relationships vary with species’ competitive ability. Demographic parameters, density, and occurrence probability were estimated for 108 tree species from four temperate forest inventory surveys (Québec, Western US, France and Switzerland). We used published information of shade tolerance as indicators of light competition strategy, assuming that high tolerance denotes high competitive capacity in stable forest environments. Interestingly, relationships between demographic parameters and occurrence probability did not vary substantially across degrees of shade tolerance and regions. Although they were influenced by the uncertainty in the estimation of the demographic parameters, we found that r was generally negatively correlated with Pocc, while N, and for most regions K, was generally positively correlated with Pocc. Thus, in temperate forest trees the regions of highest occurrence probability

  7. Taphonomy of coral reefs from Southern Lagoon of Belize

    SciTech Connect

    Westphall, M.J.; Ginsburg, R.N.

    1985-02-01

    The Southern Lagoon of the Belize barrier complex, an area of some 600 km/sup 2/, contains a tremendous number of lagoon reefs, which range in size from patches several meters across to rhomboidal-shaped structures several kilometers in their long dimension. These lagoon reefs are remarkable because they have Holocene sediment accumulations in excess of 13 m consisting almost entirely of coral debris and lime mud and sand, and rise up to 30 m above the surrounding lagoon floor with steeply sloping sides (50-80/sup 0/), yet are totally uncemented. The reef-building biota and their corresponding deposits were studied at a representative reef, the rhomboidal complex of Channel Cay. As with many of the reefs in this area, the steeply sloping flanks of Channel Cay are covered mainly by the branched staghorn coral Acropora cervicornis and ribbonlike and platy growth of Agaricia spp. The living corals are not cemented to the substrate, but are merely intergrown. Fragmented pieces of corals accumulate with an open framework below the living community; this open framework is subsequently infilled by lime muds and sands produced mainly from bioerosion. Results from probing and coring suggest that the bafflestone fabric of coral debris and sediment extends at least 13 m into the subsurface. Radiocarbon-age estimates indicate these impressive piles of coral rubble and sediment have accumulated in the past 9000 yr (giving a minimum accumulation rate of 1.4 m/1000 yr) and illustrate the potential for significant carbonate buildups without the need for early lithification.

  8. Taphonomy of the Tianyuandong human skeleton and faunal remains.

    PubMed

    Fernández-Jalvo, Yolanda; Andrews, Peter; Tong, HaoWen

    2015-06-01

    Tianyuan Cave is an Upper Palaeolithic site, 6 km from the core area of the Zhoukoudian Site Complex. Tianyuandong (or Tianyuan Cave) yielded one ancient (though not the earliest) fossil skeleton of Homo sapiens in China (42-39 ka cal BP). Together with the human skeleton, abundant animal remains were found, but no stone tools were recovered. The animal fossil remains are extremely fragmentary, in contrast to human skeletal elements that are, for the most part, complete. We undertook a taphonomic study to investigate the circumstances of preservation of the human skeleton in Tianyuan Cave, and in course of this we considered four hypotheses: funerary ritual, cannibalism, carnivore activity or natural death. Taphonomic results characterize the role of human action in the site and how these agents acted in the past. Because of disturbance of the human skeleton during its initial excavation, it is not known if it was in a grave cut or if there was any funerary ritual. No evidence was found for cannibalism or carnivore activity in relation to the human skeleton, suggesting natural death as the most reasonable possibility. PMID:25929706

  9. Taphonomy of the Tianyuandong human skeleton and faunal remains.

    PubMed

    Fernández-Jalvo, Yolanda; Andrews, Peter; Tong, HaoWen

    2015-06-01

    Tianyuan Cave is an Upper Palaeolithic site, 6 km from the core area of the Zhoukoudian Site Complex. Tianyuandong (or Tianyuan Cave) yielded one ancient (though not the earliest) fossil skeleton of Homo sapiens in China (42-39 ka cal BP). Together with the human skeleton, abundant animal remains were found, but no stone tools were recovered. The animal fossil remains are extremely fragmentary, in contrast to human skeletal elements that are, for the most part, complete. We undertook a taphonomic study to investigate the circumstances of preservation of the human skeleton in Tianyuan Cave, and in course of this we considered four hypotheses: funerary ritual, cannibalism, carnivore activity or natural death. Taphonomic results characterize the role of human action in the site and how these agents acted in the past. Because of disturbance of the human skeleton during its initial excavation, it is not known if it was in a grave cut or if there was any funerary ritual. No evidence was found for cannibalism or carnivore activity in relation to the human skeleton, suggesting natural death as the most reasonable possibility.

  10. Observations on ichnology, taphonomy and epibiota in the freshwater realm

    NASA Astrophysics Data System (ADS)

    Lawfield, Andrew Martin William

    Ichnology concerns the study of interactions between organisms and both soft and hard substrates. Actualistic observation of a modern day river channel molluscan assemblage including unionid and sphaeriid bivalves and gastropods within the Saint John River, Fredericton, New Brunswick, Canada reveals their production of almond shaped Lockeia like resting traces, together with varied, horizontally aligned furrowed, meandering, looping and spiral plan view locomotion/grazing traces. These traces occur within a shifting sand softground substrate. An emersion event associated with a low water level allowed collection of unionid samples, amongst which Elliptio complanata predominates, alongside Lampsilis radiata and Anodonta implicata. Detailed analysis of shell material, with methodologies including scanning electron microscopy (SEM) reveals microboring, various taphonomic signatures and the development of biofilm and extracellular polymeric substances (EPS). These are often associated with one another and their location closely influenced by the shell structure. Taphonomic decay of the shells was noted, with the external periostracum and prismatic aragonite layers decaying, particularly in the umbonal region. Physical puncturing and tearing penetrate the periostracum. Exposed regions of nacreous aragonite are smoothed by a combination of chemical interaction with the water column and physical abrasion from agitated silt and sand sediments. Surface pitting and circular to ovoid penetrations with morphologies comparable to Oichnus borings are noted and their formation is tentatively attributed to bacterial decay processes. In marine settings, the outer protective periostracum of molluscs often possesses physical and chemical defence mechanisms intended to inhibit the attachment of epibiota. Our observations suggest their absence from unionids, with final instar larval or pupal stage Trichoptera, including Goera, Neophylax and Helicopsyche selectively attached to regions of intact periostracum in preference to exposed aragonite on dead shells. In addition, live unionids can display thick growths of cyanobacterial or cyanophyte dominated microbial mat. Biofilm and extracellular polymeric substances, with bacterial, diatomaceous and filamentous components are also observed, often displaying a close association with both microboring and the shells conchiolin layers. Several styles of microboring are noted, with predominantly surficial and both simple tubular and complex network penetrative styles observed. Microborings may be attributed to cyanobacterial, cyanophyte and fungal activity.

  11. Performance Analysis of Occurrences January 1, 2011-December 31, 2011

    SciTech Connect

    Ludwig, M

    2012-03-16

    This report documents the analysis of the occurrences during the period January 1, 2011 through December 31, 2011. The report compares LLNL occurrences by reporting criteria and significance category to see if LLNL is reporting occurrences along similar percentages as other DOE sites. The three-year trends are analyzed. It does not include the analysis of the causes or the lessons learned from the occurrences, as they are analyzed separately. The number and types of occurrences that LLNL reports to DOE varies over time. This variation can be attributed to normally occurring changes in frequency; DOE's or LLNL's heightened interest in a particular subject area; changes in LLNL processes; or emerging problems. Since all of the DOE sites use the same reporting criteria, it is helpful to understand if LLNL is consistent with or diverging from reporting at other sites. This section compares the normalized number of occurrences reported by LLNL and other DOE sites. In order to compare LLNL occurrence reports to occurrence reports from other DOE sites, we normalized (or standardized) the data from the sites. DOE sites vary widely in their budgets, populations, and scope of work and these variations may affect reporting frequency. In addition, reports are required for a wide range of occurrence types, some of which may not be applicable to all DOE sites. For example, one occurrence reporting group is Group 3, Nuclear Safety Basis, and not all sites have nuclear operations. Because limited information is available for all sites, the sites were normalized based on best available information. Site effort hours were extracted from the DOE Computerized Accident Incident Reporting System (CAIRS) and used to normalize (or standardize) the number of occurrences by site. Effort hours are those hours that employees normally work and do not include vacation, holiday hours etc. Sites are responsible for calculating their effort hours and ensuring entry into CAIRS. Out of the 30 DOE

  12. Mode of occurrence of chromium in four US coals

    USGS Publications Warehouse

    Huggins, Frank E.; Shah, N.; Huffman, G.P.; Kolker, A.; Crowley, S.; Palmer, C.A.; Finkelman, R.B.

    2000-01-01

    The mode of occurrence of chromium in three US bituminous coals and one US subbituminous has been examined using both X-ray absorption fine structure (XAFS) spectroscopy and a selective leaching protocol supplemented by scanning electron microscopy (SEM) and electron microprobe measurements. A synthesis of results from both methods indicates that chromium occurs principally in two forms in the bituminous coals: the major occurrence of chromium is associated with the macerals and is not readily leached by any reagent, whereas a second, lesser occurrence, which is leachable in hydrofluoric acid (HF), is associated with the clay mineral, illite. The former occurrence is believed to be a small particle oxyhydroxide phase (CrO(OH)). One coal also contained a small fraction (<5%) of the chromium in the form of a chromian magnetite, and the leaching protocol indicated the possibility of a similar small fraction of chromium in sulfide form in all three coals. There was little agreement between the two techniques on the mode of occurrence of chromium in the subbituminous coal; however, only a limited number of subbituminous coals have been analyzed by either technique. The chromium in all four coals was trivalent as no evidence was found for the Cr6+ oxidation state in any coal.

  13. Defense programs occurrence analysis report for third quarter CY-1991

    SciTech Connect

    Not Available

    1991-12-01

    The quarterly Defense Programs Occurrence Analysis Report (DPOAR) is compiled by the Office of Self-Assessment and Emergency Management (DP-9). It utilizes the Occurrence Reporting and Processing System (ORPS) data to assess the quality and effectiveness of the reporting process and the significance of the occurrences. In addition, areas where further improvement and corrective actions are necessary is fully demonstrated by an analysis of the data. The results of the assessment may also be used as the basis for conducting other evaluations such as the diagnostic and augmented evaluations. This quarterly report provides feedback to DOE/DP and contractor management to improve the control of operations and achieve a higher standard of excellence. The report analyzes one year of ORPS data at the end of each calendar quarter, therefore, the performance of DP Field Offices and facilities will be continuously compared to their past quarter and yearly performances. During this assessment from 1 October 1990 through 30 September 1991, there were a number of initiatives that were undertaken by Field Office management to improve the overall performance and the quality of the Occurrence Reporting and Processing System. These initiatives include the training of their staff for self-assessment activities. These intiatives can be found in the programs implemented according to the DOE Conduct of Operations and Occurrence Reporting and Processing of Operations Information Orders. These initiatives were found to be, based on the ORPS data, stronger at Albuquerque, Nevada, Oak Ridge Field Offices and Richland DP facilities.

  14. Occurrence of microbial indicators in various ground water sources

    SciTech Connect

    Shadix, L.C.; Newport, B.S.; Crout, S.R.; Lieberman, R.J.

    1996-11-01

    The United States Environmental Protection Agency (USEPA) and the American Water Works Association Research Foundation (AWWARF) have been collaborating in an ongoing study to research the application of molecular biology techniques versus conventional techniques for monitoring and consequently to obtain ground water microbial occurrence data. The bacterial assays described below were performed during the course of the USEPA/AWWARF study in addition to enteric virus, bacteriophage and Legionella assays to provide occurrence information and also to investigate the potential use of fecal indicator organisms as surrogates for enteric viruses. This paper presents occurrence data obtained for total coliform, Escherichia coli (E. coli), fecal enterococci and Clostridium perfringens (C. perfringens) bacteria from samples collected at thirty public ground water supplies.

  15. Fluvial network organization imprints on microbial co-occurrence networks

    PubMed Central

    Widder, Stefanie; Besemer, Katharina; Singer, Gabriel A.; Ceola, Serena; Bertuzzo, Enrico; Quince, Christopher; Sloan, William T.; Rinaldo, Andrea; Battin, Tom J.

    2014-01-01

    Recent studies highlight linkages among the architecture of ecological networks, their persistence facing environmental disturbance, and the related patterns of biodiversity. A hitherto unresolved question is whether the structure of the landscape inhabited by organisms leaves an imprint on their ecological networks. We analyzed, based on pyrosequencing profiling of the biofilm communities in 114 streams, how features inherent to fluvial networks affect the co-occurrence networks that the microorganisms form in these biofilms. Our findings suggest that hydrology and metacommunity dynamics, both changing predictably across fluvial networks, affect the fragmentation of the microbial co-occurrence networks throughout the fluvial network. The loss of taxa from co-occurrence networks demonstrates that the removal of gatekeepers disproportionately contributed to network fragmentation, which has potential implications for the functions biofilms fulfill in stream ecosystems. Our findings are critical because of increased anthropogenic pressures deteriorating stream ecosystem integrity and biodiversity. PMID:25136087

  16. Occurrence of the megatoothed sharks (Lamniformes: Otodontidae) in Alabama, USA.

    PubMed

    Ehret, Dana J; Ebersole, Jun

    2014-01-01

    The Otodontidae include some of the largest sharks to ever live in the world's oceans (i.e., Carcharocles megalodon). Here we report on Paleocene and Eocene occurrences of Otodus obliquus and Carcharocles auriculatus from Alabama, USA. Teeth of Otodus are rarely encountered in the Gulf Coastal Plain and this report is one of the first records for Alabama. Carcharocles auriculatus is more common in the Eocene deposits of Alabama, but its occurrence has been largely overlooked in the literature. We also refute the occurrence of the Oligocene Carcharocles angustidens in the state. Raised awareness and increased collecting of under-sampled geologic formations in Alabama will likely increase sample sizes of O. obliquus and C. auriculatus and also might unearth other otodontids, such as C. megalodon and C. chubutensis. PMID:25332848

  17. Fluvial network organization imprints on microbial co-occurrence networks.

    PubMed

    Widder, Stefanie; Besemer, Katharina; Singer, Gabriel A; Ceola, Serena; Bertuzzo, Enrico; Quince, Christopher; Sloan, William T; Rinaldo, Andrea; Battin, Tom J

    2014-09-01

    Recent studies highlight linkages among the architecture of ecological networks, their persistence facing environmental disturbance, and the related patterns of biodiversity. A hitherto unresolved question is whether the structure of the landscape inhabited by organisms leaves an imprint on their ecological networks. We analyzed, based on pyrosequencing profiling of the biofilm communities in 114 streams, how features inherent to fluvial networks affect the co-occurrence networks that the microorganisms form in these biofilms. Our findings suggest that hydrology and metacommunity dynamics, both changing predictably across fluvial networks, affect the fragmentation of the microbial co-occurrence networks throughout the fluvial network. The loss of taxa from co-occurrence networks demonstrates that the removal of gatekeepers disproportionately contributed to network fragmentation, which has potential implications for the functions biofilms fulfill in stream ecosystems. Our findings are critical because of increased anthropogenic pressures deteriorating stream ecosystem integrity and biodiversity. PMID:25136087

  18. Occurrence of the megatoothed sharks (Lamniformes: Otodontidae) in Alabama, USA.

    PubMed

    Ehret, Dana J; Ebersole, Jun

    2014-01-01

    The Otodontidae include some of the largest sharks to ever live in the world's oceans (i.e., Carcharocles megalodon). Here we report on Paleocene and Eocene occurrences of Otodus obliquus and Carcharocles auriculatus from Alabama, USA. Teeth of Otodus are rarely encountered in the Gulf Coastal Plain and this report is one of the first records for Alabama. Carcharocles auriculatus is more common in the Eocene deposits of Alabama, but its occurrence has been largely overlooked in the literature. We also refute the occurrence of the Oligocene Carcharocles angustidens in the state. Raised awareness and increased collecting of under-sampled geologic formations in Alabama will likely increase sample sizes of O. obliquus and C. auriculatus and also might unearth other otodontids, such as C. megalodon and C. chubutensis.

  19. Occurrence of the megatoothed sharks (Lamniformes: Otodontidae) in Alabama, USA

    PubMed Central

    Ebersole, Jun

    2014-01-01

    The Otodontidae include some of the largest sharks to ever live in the world’s oceans (i.e., Carcharocles megalodon). Here we report on Paleocene and Eocene occurrences of Otodus obliquus and Carcharocles auriculatus from Alabama, USA. Teeth of Otodus are rarely encountered in the Gulf Coastal Plain and this report is one of the first records for Alabama. Carcharocles auriculatus is more common in the Eocene deposits of Alabama, but its occurrence has been largely overlooked in the literature. We also refute the occurrence of the Oligocene Carcharocles angustidens in the state. Raised awareness and increased collecting of under-sampled geologic formations in Alabama will likely increase sample sizes of O. obliquus and C. auriculatus and also might unearth other otodontids, such as C. megalodon and C. chubutensis. PMID:25332848

  20. On the Occurrence of Counter Equatorial Electrojet Over Africa

    NASA Astrophysics Data System (ADS)

    Rabiu, A. B.; O, F. O.; Uozumi, T.

    2014-12-01

    This study engaged year 2009 data of the horizontal component of the Earth's magnetic field obtained from four geomagnetic observatories in the East and West African meridians to study the occurrence of counter electrojet along the African longitudes: Ilorin (Nigeria: 4.68°E, 8.50°N; dip latitude, 1.82°S), Addis Ababa (Ethiopia: 38.77°E, 9.04°N; dip latitude, 0.18°N), Lagos (Nigeria: 3.27°E, 6.48°N; dip latitude 3.04°S), and Nairobi (Kenya: 36.48°E, 1.16°S; dip latitude 10.65°S). Data was obtained from the Magnetic Data Acquisition System (MAGDAS) installed and managed by the International Centre for Space Weather Science and Education (ICSWSE), Japan. The diurnal and seasonal distribution of the occurrence of CEJ at Ilorin (West Africa) and Addis Ababa (East Africa) were examined. It was observed that the occurrence of morning CEJ is much prevalent along the East African longitude (90%) than the West African longitude (80.9%), while the evening CEJ is dominant along the West African longitude (82.9%) than the East African longitude (50%). The longitudinal variability in the occurrence of CEJ along these longitudes is attributed to the differences in meridional currents, variation in the local electric field in the ionosphere, and the gravity wave associated vertical winds. The simultaneity and asymmetry in the occurrence of CEJ were also investigated. The morning simultaneity is maximum (100%) is maximum than the evening simultaneity. The occurrence of Asym-2 is much prevalent at both longitudes (41.3%) than asym-1 (4.9%).

  1. Detection, Occurrence and Fate of Emerging Contaminants in Agricultural Environments.

    PubMed

    Snow, Daniel D; Cassada, David A; Bartelt-Hunt, Shannon L; Li, Xu; D'Alessio, Matteo; Zhang, Yun; Zhang, Yuping; Sallach, J Brett

    2016-10-01

    A total of 59 papers published in 2015 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, steroids, antibiotic resistance genes in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Steroid Hormones, Pharmaceutical Contaminants, Transformation Products, and "Antibiotic Resistance, Drugs, Bugs and Genes".

  2. Familial occurrence of congenital incomplete prepyloric mucosal diaphragm.

    PubMed Central

    Gahukamble, D B

    1998-01-01

    Incomplete prepyloric mucosal diaphragm (IPMD) is an uncommon congenital anomaly that leads to gastric outlet obstruction in infancy and childhood. This report describes the occurrence of IPMD in six children in a closely knit tribal family from a geographically isolated desert town with a small population in the Sahara. Their records showed similarities of clinical, radiological, operative, and histopathological features. These features, as well as its occurrence in brothers, sisters, and cousins, suggest that this unusual anomaly is transmitted as an autosomal recessive trait. Images PMID:9863605

  3. Detection, Occurrence and Fate of Emerging Contaminants in Agricultural Environments.

    PubMed

    Snow, Daniel D; Cassada, David A; Bartelt-Hunt, Shannon L; Li, Xu; D'Alessio, Matteo; Zhang, Yun; Zhang, Yuping; Sallach, J Brett

    2016-10-01

    A total of 59 papers published in 2015 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, steroids, antibiotic resistance genes in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Steroid Hormones, Pharmaceutical Contaminants, Transformation Products, and "Antibiotic Resistance, Drugs, Bugs and Genes". PMID:27620078

  4. Numerical and laboratory simulation of fault motion and earthquake occurrence

    NASA Technical Reports Server (NTRS)

    Cohen, S. C.

    1978-01-01

    Simple linear rheologies were used with elastic forces driving the main events and viscoelastic forces being important for aftershock and creep occurrence. Friction and its dependence on velocity, stress, and displacement also plays a key role in determining how, when, and where fault motion occurs. The discussion of the qualitative behavior of the simulators focuses on the manner in which energy was stored in the system and released by the unstable and stable sliding processes. The numerical results emphasize the statistics of earthquake occurrence and the correlations among source parameters.

  5. A rare occurrence of geminated-taloned maxillary lateral incisor.

    PubMed

    Neeraja, R; Kayal, Vizhi G

    2012-05-01

    The talon cusp is a developmental anomaly characterized by the presence of an accessory cusp like structure projecting from the cingulum area of the anterior teeth. Gemination is an anomaly caused by a single tooth germ that attempted to divide during its development. These developmental anomalies may cause clinical problems including esthetic impairment, pain, caries and tooth crowding. Co-occurrence of two anomalies in a teeth is rare. This paper presents an unusual case of talon cusp on geminated permanent lateral incisor. How to cite this article: Neeraja R, Kayal VG. A Rare Occurrence of Geminated-Taloned Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2012;5(2):136-138.

  6. Periodicity in the occurrence of equatorial plasma bubbles

    NASA Astrophysics Data System (ADS)

    Choi, J.; Kim, Y.; Kil, H.; Kwak, Y.; Lee, W.

    2013-12-01

    The observations of equatorial plasma bubbles by low-inclination orbit satellites show periodic occurrence of bubbles along satellite orbits. The periodicity in the bubble occurrence provides a useful tool for identifying the role of gravity waves in the creation of bubbles. In this study, we investigate the variability of the periodicity in the bubble occurrence by analyzing the observations of Communication/Navigation Outage Forecasting System (C/NOFS) and the first Republic of China satellite (ROCSAT-1). Here the periodicity indicates spatial periodicity and is derived by applying a Fourier analysis to the electron densities projected onto the magnetic apex height. Our preliminary results show an occurrence of significant amplitudes of periodicity peaks on the spatial scale range of 50-1000 km. The periodicity on small scales may be associated with the bifurcation of bubbles or to the creation of multiple bubbles for one wave seeding. The periodicity on larger scales is considered to be related with the scale size of a seeding mechanism. We present statistics of the periodicity and the coincident satellite observations of periodic bubbles with ground observations.

  7. The Co-Occurrence of Quotatives with Mimetic Performances.

    ERIC Educational Resources Information Center

    Buchstaller, Isabelle

    2003-01-01

    This paper discusses mimesis, the direct representation and total imitation of an event. It studies the co-occurrence of quotative verbs with mimetic enactment based on two corpora of U.S. American English, both available through the University of Pennsylvania Data Consortium. The Switchboard Corpus has 542 speakers ranging in age from 20-60 years…

  8. Two unusual occurrences of trichomoniasis: rapid species identification by PCR.

    PubMed

    Bellanger, A P; Cabaret, O; Costa, J M; Foulet, F; Bretagne, S; Botterel, F

    2008-09-01

    PCR analysis in two unusual occurrences of trichomoniasis, trichomonal empyema due to Trichomonas tenax and Trichomonas vaginalis in an infant urine sample, allowed us to obtain rapid and accurate trichomonad species identification. The weak sensitivity of wet preparations and the low viability of the flagellates can be remedied by the PCR method. PMID:18632901

  9. OCCURRENCE OF VANCOMYCIN RESISTANT ENTEROCOCCI IN ANIMAL FECES

    EPA Science Inventory

    A survey was conducted to determine the occurrence of vancomycin resistant Enterococci (VRE) in animal and human fecal samples. A selective agar mEI, and mEI supplemented with 4 micrograms/ml vancomycin was used in a membrane filtration procedure to determine quantitative levels ...

  10. How well can we predict forage species occurrence and abundance?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As part of a larger effort focused on forage species production and management, we have been developing a statistical modeling approach to predict the probability of species occurrence and the abundance for Orchard Grass over the Northeast region of the United States using two selected statistical m...

  11. OCCURRENCE OF A NEW GENERATION OF DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    A survey of disinfection by-product (DBP) occurrence in the United States was conducted at 12 drinking water treatment plants. In addition to currently regulated DBPs, more than 50 DBPs that rated a high priority for potential toxicity were studied. These priority DBPs included...

  12. A hierarchical community occurrence model for North Carolina stream fish

    USGS Publications Warehouse

    Midway, S.R.; Wagner, Tyler; Tracy, B.H.

    2016-01-01

    The southeastern USA is home to one of the richest—and most imperiled and threatened—freshwater fish assemblages in North America. For many of these rare and threatened species, conservation efforts are often limited by a lack of data. Drawing on a unique and extensive data set spanning over 20 years, we modeled occurrence probabilities of 126 stream fish species sampled throughout North Carolina, many of which occur more broadly in the southeastern USA. Specifically, we developed species-specific occurrence probabilities from hierarchical Bayesian multispecies models that were based on common land use and land cover covariates. We also used index of biotic integrity tolerance classifications as a second level in the model hierarchy; we identify this level as informative for our work, but it is flexible for future model applications. Based on the partial-pooling property of the models, we were able to generate occurrence probabilities for many imperiled and data-poor species in addition to highlighting a considerable amount of occurrence heterogeneity that supports species-specific investigations whenever possible. Our results provide critical species-level information on many threatened and imperiled species as well as information that may assist with re-evaluation of existing management strategies, such as the use of surrogate species. Finally, we highlight the use of a relatively simple hierarchical model that can easily be generalized for similar situations in which conventional models fail to provide reliable estimates for data-poor groups.

  13. Occurrence and distribution of nematodes in Idaho crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surveys were conducted in Idaho during the 2000-2006 cropping seasons to study the occurrence, population density, host association and distribution of plant-parasitic nematodes associated with major crops, grasses and weeds. Eighty-four species and 43 genera of plant-parasitic nematodes were record...

  14. Folivory and disease occurrence on Ludwigia hexapetala in Guntersville Reservoir

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report leaf feeding, disease occurrence and associated indigenous herbivore/fungal pathogen communities on the introduced wetland species Ludwigia hexapetala at Guntersville Reservoir, AL. Plant populations were sampled on three dates from May to September, 2014. A complex of indigenous herbivore...

  15. Occurrence of Stalking Victimization among Female and Male Undergraduate Students

    ERIC Educational Resources Information Center

    Myers, Rachel K.; Nelson, Deborah B.; Forke, Christine M.

    2016-01-01

    We examined the occurrence of stalking victimization among female and male undergraduate students attending three urban colleges. Specifically, we explored the proportion of students who experienced only stalking victimization and the relationship to the perpetrator identified by victims of stalking. Our findings suggest that stalking…

  16. Factors Affecting the Occurrence of Faculty-Doctoral Student Coauthorship

    ERIC Educational Resources Information Center

    Maher, Michelle A.; Timmerman, Briana Crotwell; Feldon, David F.; Strickland, Denise

    2013-01-01

    Using faculty narratives, this study identifies factors affecting the occurrence of faculty-doctoral student coauthorship. Norms of the discipline, resources, faculty goals for students, faculty goals for themselves, and institutional expectations emerged as dominant factors. Each factor is explored separately and as part of an interlocking…

  17. Harsh Corporal Punishment of Yemeni Children: Occurrence, Type and Associations

    ERIC Educational Resources Information Center

    Alyahri, Abdullah; Goodman, Robert

    2008-01-01

    Objective: To examine the occurrence, type and associations of harsh corporal punishment in Yemen. Methods: Caregiver and teacher reports were obtained on 1,196 Yemeni 7-10-year olds obtained by systematic random sampling of children in the 1st to 4th grades of urban and rural schools. Caregivers (86% mothers) reported on disciplinary practices,…

  18. Quantifying the probability of meteotsunami occurrence from synoptic atmospheric patterns

    NASA Astrophysics Data System (ADS)

    Šepić, Jadranka; Vilibić, Ivica; Monserrat, Sebastian

    2016-10-01

    A synoptic atmospheric index is constructed for the region of the Balearic Islands, Spain. The index links the occurrence of meteotsunamis, i.e., atmospherically induced high-frequency sea level oscillations (2 min < T < 120 min), to contemporaneous meteorological synoptic conditions above the region. The correlation between the synoptic index and wave heights is found to be significant and high (up to 0.75). The vertical wind profile is recognized as the most important variable governing the sea level response to atmospheric conditions. The probability of the occurrence of a meteotsunami can be then evaluated from synoptic atmospheric variables. The results show that there exists an index threshold, below which the probability for an intense meteotsunami occurrence is extremely low. However, meteotsunami-favorable synoptic conditions (the index exceeding the threshold value) are crucial but insufficient; some mesoscale features, not reflected in the synoptic pattern, are found to play an important role in meteotsunami generation. The constructed index is potentially applicable to other world locations where a set of tsunamigenic synoptic conditions may be defined in a similar way as at the Balearic Islands. The index can be used to estimate the rate of meteotsunami occurrence under the conditions of past, present, and future climates. It can also be effectively used in meteotsunami warning systems, especially to switch between a "silent mode" (index below the threshold value) to an "event mode."

  19. 46 CFR 326.4 - Reports of accidents and occurrences.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false Reports of accidents and occurrences. 326.4 Section 326.4 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY MARINE PROTECTION AND INDEMNITY INSURANCE UNDER AGREEMENTS WITH AGENTS § 326.4 Reports of accidents...

  20. 46 CFR 326.4 - Reports of accidents and occurrences.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Reports of accidents and occurrences. 326.4 Section 326.4 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY MARINE PROTECTION AND INDEMNITY INSURANCE UNDER AGREEMENTS WITH AGENTS § 326.4 Reports of accidents...

  1. 46 CFR 326.4 - Reports of accidents and occurrences.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 8 2012-10-01 2012-10-01 false Reports of accidents and occurrences. 326.4 Section 326.4 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY MARINE PROTECTION AND INDEMNITY INSURANCE UNDER AGREEMENTS WITH AGENTS § 326.4 Reports of accidents...

  2. 46 CFR 326.4 - Reports of accidents and occurrences.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Reports of accidents and occurrences. 326.4 Section 326.4 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY MARINE PROTECTION AND INDEMNITY INSURANCE UNDER AGREEMENTS WITH AGENTS § 326.4 Reports of accidents...

  3. 46 CFR 326.4 - Reports of accidents and occurrences.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 8 2014-10-01 2014-10-01 false Reports of accidents and occurrences. 326.4 Section 326.4 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY MARINE PROTECTION AND INDEMNITY INSURANCE UNDER AGREEMENTS WITH AGENTS § 326.4 Reports of accidents...

  4. On the Occurrence of Standardized Regression Coefficients Greater than One.

    ERIC Educational Resources Information Center

    Deegan, John, Jr.

    1978-01-01

    It is demonstrated here that standardized regression coefficients greater than one can legitimately occur. Furthermore, the relationship between the occurrence of such coefficients and the extent of multicollinearity present among the set of predictor variables in an equation is examined. Comments on the interpretation of these coefficients are…

  5. OCCURRENCE OF INTRINSIC VANCOMYCIN RESISTANT ENTEROCOCCI IN ANIMAL FECES

    EPA Science Inventory

    A survey was conducted to determine the occurrence of vancomycin resistant enterococci (VRE) in animal and human fecal samples. Fecal samples from 14 animal species and humans were analyzed by quantitative culture for enterococci and VRE. Over 800 VRE isolates were characterize...

  6. The effect of forests on rockfall occurrence frequency

    NASA Astrophysics Data System (ADS)

    Moos, Christine; Dorren, Luuk; Stoffel, Markus

    2016-04-01

    Many forests in mountain regions protect people, settlements and infrastructure from rockfall and play an important role in risk prevention. Despite recent advances regarding forest-rockfall interactions, open questions still remain, namely on how the mitigating effect of forests can be quantitatively integrated into rockfall risk analyses. The quantification of the influence of forests on rockfall occurrence frequency is particularly demanding, even more so when related to elements at risk. The goal of this study is to quantify the effect of forests on the occurrence frequency based on rockfall simulations with the three-dimensional, process-based model Rockyfor3D. We define a constant rockfall release probability based on a power-law magnitude-frequency distribution, which is used to simulate rockfall events over a period of 1000 yrs on a virtually constructed slope. The simulations are conducted for different forest and non-forest scenarios under varying terrain conditions. These simulations firstly provide input data for the determination of rockfall occurrence frequencies at five different evaluation zones situated at 0, 150, 300, 450, and 500 m from the release area. Secondly, based on multivariate statistical models, we try to find out how specific forest and terrain characteristics control the rockfall occurrence frequency along a slope. The results for a 0.5 m3 block show, for example, that at a distance of 500 m from the release area, the occurrence frequency (expressed as a return period in years) changes from 30 yrs on a non-forested to more than 1000 yrs on a forested slope. The difference in the frequency increases with increasing distance from the release area and is less pronounced for larger block volumes (> ~1.2 m3). The results of the statistical analyses allow to quantify the effect of specific forest and terrain characteristics on the reduction of the occurrence frequency. For example, a forested slope length of 100 m with a dense forest (basal

  7. Simulating multimodal seasonality in extreme daily precipitation occurrence

    NASA Astrophysics Data System (ADS)

    Tye, Mari R.; Blenkinsop, Stephen; Fowler, Hayley J.; Stephenson, David B.; Kilsby, Christopher G.

    2016-06-01

    Floods pose multi-dimensional hazards to critical infrastructure and society and these hazards may increase under climate change. While flood conditions are dependent on catchment type and soil conditions, seasonal precipitation extremes also play an important role. The extreme precipitation events driving flood occurrence may arrive non-uniformly in time. In addition, their seasonal and inter-annual patterns may also cause sequences of several events and enhance likely flood responses. Spatial and temporal patterns of extreme daily precipitation occurrence are characterized across the UK. Extreme and very heavy daily precipitation is not uniformly distributed throughout the year, but exhibits spatial differences, arising from the relative proximity to the North Atlantic Ocean or North Sea. Periods of weeks or months are identified during which extreme daily precipitation occurrences are most likely to occur, with some regions of the UK displaying multimodal seasonality. A Generalized Additive Model is employed to simulate extreme daily precipitation occurrences over the UK from 1901 to 2010 and to allow robust statistical testing of temporal changes in the seasonal distribution. Simulations show that seasonality has the strongest correlation with intra-annual variations in extreme event occurrence, while Sea Surface Temperature (SST) and Mean Sea Level Pressure (MSLP) have the strongest correlation with inter-annual variations. The north and west of the UK are dominated by MSLP in the mid-North Atlantic and the south and east are dominated by local SST. All regions now have a higher likelihood of autumnal extreme daily precipitation than earlier in the twentieth century. This equates to extreme daily precipitation occurring earlier in the autumn in the north and west, and later in the autumn in the south and east. The change in timing is accompanied by increases in the probability of extreme daily precipitation occurrences during the autumn, and in the number of

  8. Modeling the Climatology of Tornado Occurrence with Bayesian Inference

    NASA Astrophysics Data System (ADS)

    Cheng, Vincent Y. S.

    Our mechanistic understanding of tornadic environments has significantly improved by the recent technological enhancements in the detection of tornadoes as well as the advances of numerical weather predictive modeling. Nonetheless, despite the decades of active research, prediction of tornado occurrence remains one of the most difficult problems in meteorological and climate science. In our efforts to develop predictive tools for tornado occurrence, there are a number of issues to overcome, such as the treatment of inconsistent tornado records, the consideration of suitable combination of atmospheric predictors, and the selection of appropriate resolution to accommodate the variability in time and space. In this dissertation, I address each of these topics by undertaking three empirical (statistical) modeling studies, where I examine the signature of different atmospheric factors influencing the tornado occurrence, the sampling biases in tornado observations, and the optimal spatiotemporal resolution for studying tornado occurrence. In the first study, I develop a novel Bayesian statistical framework to assess the probability of tornado occurrence in Canada, in which the sampling bias of tornado observations and the linkage between lightning climatology and tornadogenesis are considered. The results produced reasonable probability estimates of tornado occurrence for the under-sampled areas in the model domain. The same study also delineated the geographical variability in the lightning-tornado relationship across Canada. In the second study, I present a novel modeling framework to examine the relative importance of several key atmospheric variables (e.g., convective available potential energy, 0-3 km storm-relative helicity, 0-6 km bulk wind difference, 0-tropopause vertical wind shear) on tornado activity in North America. I found that the variable quantifying the updraft strength is more important during the warm season, whereas the effects of wind

  9. Occurrence of veterinary pharmaceuticals in the aquatic environment in Flanders

    NASA Astrophysics Data System (ADS)

    Servaes, K.; Vanermen, G.; Seuntjens, P.

    2009-04-01

    There is a growing interest in the occurrence of pharmaceuticals in the aquatic environment. Pharmaceuticals are classified as so-called ‘emerging pollutants'. ‘Emerging pollutants' are not necessarily new chemical compounds. Often these compounds are already present in the environment for a long time. But, their occurrence and especially their impact on the environment has only recently become clear. Consequently, data on their occurrence are rather scarce. In this study, we focus on the occurrence of veterinary pharmaceuticals in surface water in Flanders. We have only considered active substances administered to cattle, pigs and poultry. Based on the literature and information concerning the use in Belgium, a selection of 25 veterinary pharmaceuticals has been made. This selection consists of the most important antibiotics and antiparasitic substances applied in veterinary medicine in Belgium. We develop an analytical methodology based on UPLC-MS/MS for the detection of these veterinary pharmaceuticals in surface water. Therefore, the mass characteristics as well as the optimum LC conditions will be determined. To obtain limits of detection as low as possible, the samples are concentrated prior to analysis using solid phase extraction (SPE). Different SPE cartridges will be tested during the method development. At first, this SPE sample pre-treatment is performed off-line. In a next step, online SPE is optimized for this purpose. The analytical procedure will be subject to an in-house validation study, thereby determining recovery, repeatability (% RSD), limits of detection and limits of quantification. Finally, the developed methodology will be applied for monitoring the occurrence of veterinary pharmaceuticals in surface water and groundwater in Flanders. These water samples will be taken in areas characterized by intensive cattle breeding. Moreover, the samples will be collected during springtime. In this season, farmers apply manure, stored during winter

  10. Patterns and determinants of mammal species occurrence in India

    USGS Publications Warehouse

    Karanth, K.K.; Nichols, J.D.; Hines, J.E.; Karanth, K.U.; Christensen, N.L.

    2009-01-01

    Many Indian mammals face range contraction and extinction, but assessments of their population status are hindered by the lack of reliable distribution data and range maps. 2. We estimated the current geographical ranges of 20 species of large mammals by applying occupancy models to data from country-wide expert. We modelled species in relation to ecological and social covariates (protected areas, landscape characteristics and human influences) based on a priori hypotheses about plausible determinants of mammalian distribution patterns. 3. We demonstrated that failure to incorporate detection probability in distribution survey methods underestimated habitat occupancy for all species. 4. Protected areas were important for the distribution of 16 species. However, for many species much of their current range remains unprotected. The availability of evergreen forests was important for the occurrence of 14 species, temperate forests for six species, deciduous forests for 15 species and higher altitude habitats for two species. Low human population density was critical for the occurrence of five species, while culturally based tolerance was important for the occurrence of nine other species. 5. Rhino Rhinoceros unicornis, gaur Bos gaurus and elephant Elephas maximus showed the most restricted ranges among herbivores, and sun bear Helarctos malayanus, brown bear Ursus arctos and tiger Panthera tigris were most restricted among carnivores. While cultural tolerance has helped the survival of some mammals, legal protection has been critically associated with occurrence of most species. 6. Synthesis and applications. Extent of range is an important determinant of species conservation status. Understanding the relationship of species occurrence with ecological and socio-cultural covariates is important for identification and management of key conservation areas. The combination of occupancy models with field data from country-wide experts enables reliable estimation of species

  11. Prognosis of groundwater drought occurrence in selected catchments of Slovakia

    NASA Astrophysics Data System (ADS)

    Stojkovova, M.; Machlica, A.; Bara, M.

    2009-04-01

    The paper contains results on prognosis of groundwater drought occurrence in six selected catchments of Slovakia with different geological, hydrogeological and climatic conditions. Prognoses were made using BILAN model. Climatic scenarios CCCM1997, CCCM2000 (Canadian model CGCM.1 and CGCM.2 modified on conditions in Slovakia) and GISS1998 were used. Groundwater drought occurrence was assessed for time-frames 2030 and 2075. Each year of the whole assessed period of 24 years (1982-2005) was classified according to the water bearing degree of the stream taking into account the yearly precipitation amounts (Majercakova, et al., 2007). Three types of dry years - very dry, medium dry and moderately dry were defined. The prognosis values for 2030 and 2075 were compared with the reference period 1971-1990. Chvojnica River catchment (Lopasov profile), located in Neogene sedimentary rocks is characterized by occurrence of 26 % of dry years (very dry, medium or moderately dry) within the period 1982-2005. Prognosis of the groundwater runoff changes showed not very expressive decrease, in about 3.6-4 % in comparison with the reference period. Tuzina River catchment (Tuzina profile), located in crystalline, Mesozoic and Neogene sedimentary rocks, is characterized by occurrence of 25 % of dry years. Values of the groundwater runoff would decrease not very expressively, in about 5-7 %. These two catchments were assessed using GISS1998 climate change scenario. Groundwater changes in four other catchments were evaluated using CCCM scenarios. Topla River catchment (Bardejov profile), located in Paleogene flysh rocks, is characterized by occurrence of 58 % of dry periods. Values of the groundwater runoff would decrease importantly - in about 59-88 %. Bela River catchment (Podbanske profile), built by granitic and glaciofluvial rocks, is characterized by occurrence of 13 % of dry periods. Values of the groundwater runoff would decrease in about 42-63 %. Boca River catchment (Kralova

  12. Estimation of freak wave occurrence in shallow water regions

    NASA Astrophysics Data System (ADS)

    Kashima, Hiroaki

    2014-05-01

    In the last two decades, freak waves have become an important topic in engineering and science and are sometimes featured by a single and steep crest causing severe damage to offshore structures and vessels. An accurate estimation of maximum wave height and prediction of freak wave occurrence frequency is important for marine safety and ocean developments. According to several studies on freak waves, the deep-water third-order nonlinearity (quasi-resonant four-wave interactions) can lead to a significant enhancement of freak wave occurrence from normality. However, it is not clear the behavior of offshore generated freak waves shoaling to shallow water regions. In general, a numerical simulation based on Boussinesq model has been frequently and widely used to estimate wave transformation in shallow water regions and has high-level performance in the design of coast and harbor structures in Japan. However, it is difficult to describe the freak wave occurrence from deep to shallow water regions by the Boussinesq model because it can express only up to the second-order nonlinear interactions. There is a gap of governing equation between deep and shallow water regions from the extreme wave modeling point of view. It is necessary to investigate the aftereffects of generated freak waves by the third-order nonlinear interactions in deep water regions and their propagation to shallow water regions using the Boussinesq model. In this study, the model experiments in a wave tank and numerical simulations based on the Boussinesq model were conducted to estimate the freak wave occurrence from deep to shallow water regions. In the model experiments, the maximum wave height increases with an increase in kurtosis by the third-order nonlinear interactions in deep water regions. The dependence of kurtosis on freak wave occurrence weakens by the second-order nonlinear interactions associated with wave shoaling if dimensionless water depth kph becomes shallower than 1.363, which kp

  13. A specialist’s audit of aggregated occurrence records

    PubMed Central

    Mesibov, Robert

    2013-01-01

    Abstract Occurrence records for named, native Australian millipedes from the Global Biodiversity Information Facility (GBIF) and the Atlas of Living Australia (ALA) were compared with the same records from the Millipedes of Australia (MoA) website, compiled independently by the author. The comparison revealed some previously unnoticed errors in MoA, and a much larger number of errors and other problems in the aggregated datasets. Errors have been corrected in MoA and in some data providers’ databases, but will remain in GBIF and ALA until data providers have supplied updates to these aggregators. An audit by a specialist volunteer, as reported here, is not a common occurrence. It is suggested that aggregators should do more, or more effective, data checking and should query data providers when possible errors are detected, rather than simply disclaim responsibility for aggregated content. PMID:23794864

  14. Local structure co-occurrence pattern for image retrieval

    NASA Astrophysics Data System (ADS)

    Zhang, Ke; Zhang, Fan; Lu, Jia; Lu, Yinghua; Kong, Jun; Zhang, Ming

    2016-03-01

    Image description and annotation is an active research topic in content-based image retrieval. How to utilize human visual perception is a key approach to intelligent image feature extraction and representation. This paper has proposed an image feature descriptor called the local structure co-occurrence pattern (LSCP). LSCP extracts the whole visual perception for an image by building a local binary structure, and it is represented by a color-shape co-occurrence matrix which explores the relationship of multivisual feature spaces according to visual attention mechanism. As a result, LSCP not only describes low-level visual features integrated with texture feature, color feature, and shape feature but also bridges high-level semantic comprehension. Extensive experimental results on an image retrieval task on the benchmark datasets, corel-10,000, MIT VisTex, and INRIA Holidays, have demonstrated the usefulness, effectiveness, and robustness of the proposed LSCP.

  15. Current themes and recent advances in modelling species occurrences

    PubMed Central

    2009-01-01

    Recent years have seen a huge expansion in the range of methods and approaches that are being used to predict species occurrences. This expansion has been accompanied by many improvements in statistical methods, including more accurate ways of comparing models, better null models, methods to cope with autocorrelation, and greater awareness of the importance of scale and prevalence. However, the field still suffers from problems with incorporating temporal variation, overfitted models and poor out-of-sample prediction, confusion between explanation and prediction, simplistic assumptions, and a focus on pattern over process. The greatest advances in recent years have come from integrative studies that have linked species occurrence models with other themes and topics in ecology, such as island biogeography, climate change, disease geography, and invasive species. PMID:20948597

  16. Sea ice occurrence predicts genetic isolation in the Arctic fox.

    PubMed

    Geffen, Eli; Waidyaratne, Sitara; Dalén, Love; Angerbjörn, Anders; Vila, Carles; Hersteinsson, Pall; Fuglei, Eva; White, Paula A; Goltsman, Michael; Kapel, Christian M O; Wayne, Robert K

    2007-10-01

    Unlike Oceanic islands, the islands of the Arctic Sea are not completely isolated from migration by terrestrial vertebrates. The pack ice connects many Arctic Sea islands to the mainland during winter months. The Arctic fox (Alopex lagopus), which has a circumpolar distribution, populates numerous islands in the Arctic Sea. In this study, we used genetic data from 20 different populations, spanning the entire distribution of the Arctic fox, to identify barriers to dispersal. Specifically, we considered geographical distance, occurrence of sea ice, winter temperature, ecotype, and the presence of red fox and polar bear as nonexclusive factors that influence the dispersal behaviour of individuals. Using distance-based redundancy analysis and the BIOENV procedure, we showed that occurrence of sea ice is the key predictor and explained 40-60% of the genetic distance among populations. In addition, our analysis identified the Commander and Pribilof Islands Arctic populations as genetically unique suggesting they deserve special attention from a conservation perspective.

  17. Increased variability of tornado occurrence in the United States.

    PubMed

    Brooks, Harold E; Carbin, Gregory W; Marsh, Patrick T

    2014-10-17

    Whether or not climate change has had an impact on the occurrence of tornadoes in the United States has become a question of high public and scientific interest, but changes in how tornadoes are reported have made it difficult to answer it convincingly. We show that, excluding the weakest tornadoes, the mean annual number of tornadoes has remained relatively constant, but their variability of occurrence has increased since the 1970s. This is due to a decrease in the number of days per year with tornadoes combined with an increase in days with many tornadoes, leading to greater variability on annual and monthly time scales and changes in the timing of the start of the tornado season.

  18. Climatic factors influencing triatomine occurrence in Central-West Brazil

    PubMed Central

    Pereira, Joyce Mendes; de Almeida, Paulo Silva; de Sousa, Adair Vieira; de Paula, Aécio Moraes; Machado, Ricardo Bomfim; Gurgel-Gonçalves, Rodrigo

    2013-01-01

    We estimated the geographic distributions of triatomine species in Central-West Region of Brazil (CW) and analysed the climatic factors influencing their occurrence. A total of 3,396 records of 27 triatomine species were analysed. Using the maximum entropy method, ecological niche models were produced for eight species occurring in at least 20 municipalities based on 13 climatic variables and elevation. Triatoma sordida and Rhodnius neglectus were the species with the broadest geographic distributions in CW Brazil. The Cerrado areas in the state of Goiás were found to be more suitable for the occurrence of synanthropic triatomines than the Amazon forest areas in the northern part of the state of Mato Grosso. The variable that best explains the evaluated models is temperature seasonality. The results indicate that almost the entire region presents climatic conditions that are appropriate for at least one triatomine species. Therefore, it is recommended that entomological surveillance be reinforced in CW Brazil. PMID:23778666

  19. Co-occurrence of subacute granulomatous thyroiditis and papillary microcarcinoma.

    PubMed

    Şenel, Fatma; Karaman, Hatice; Ertan, Tamer

    2016-01-01

    Subacute thyroiditis, which is most commonly observed after a viral infection and may heal spontaneously, is an inflammatory thyroid disease. The co-occurrence of subacute thyroiditis and papillary carcinoma is quite rare. A 58-year-old male patient who applied to our hospital with the complaints of sore throat and neck swelling was performed total thyroidectomy following physical examination, ultrasound, and laboratory analysis. In histopathological examination, many granuloma structures were observed in both lobes, and a papillary microcarcinoma focus of 2 mm in diameter was seen in the left lobe. The co-occurrence of subacute thyroiditis and papillary carcinoma was deemed worthy of presentation as it is rarely observed. PMID:27405083

  20. Occurrence and pathogenicity of Naegleria fowleri in artificially heated waters

    SciTech Connect

    Sykora, J.L.; Keleti, G.; Martinez, A.J.

    1983-03-01

    The occurrence of pathogenic Naegleria fowleri in thermal discharges, recipient waters, and cooling towers of eight power plants located in western Pennsylvania was investigated for 2 years in conjunction with several environmental measurements. Pathogenic N. fowleri was detected in one cooling tower and in the discharge, receiving waters, or both of five of eight localities. The occurrence of this organism was related to elevated temperatures, but no significant correlation was found for other biological and chemical parameters. Laboratory experiments on the effect of pH on pathogenic N. fowleri documented 100% survival at a range from 2.1 to 8.15. Higher pH reduced or killed the amoebae. No case of human primary amoebic meningoencephalitis occurred during the study.

  1. Periodicities of Interplanetary Solar Type III radio bursts occurrence

    NASA Astrophysics Data System (ADS)

    Maksimovic, Milan; Navrer-Agasson, Anyssa; Sperone-Longin, Damien; Bonnin, Xavier

    2015-04-01

    We have analyzed 15 years of solar radio observations by the Wind spacecraft in order to detect automatically the Interplanetary Solar Type III radio bursts occurrence. We then compare the daily number of type III radio emissions with the daily number of sunspots. We find, as expected, a very good correlation between the two quantities. We investigate then for periodicities in the daily occurrence of type III bursts by applying a wavelet analysis and compare these periodicities to the ones obtained with the sunspots. We observe a typical Rieger-Type period of about 150 days for both the Type IIIs and the sunspots, with a temporal location of the maximum of this periodicity which is however different for the two data sets. We discuss this difference and compare our results to previous similar studies applied on ground based observations of Type III activity.

  2. A Rare Occurrence of Geminated-Taloned Maxillary Lateral Incisor

    PubMed Central

    Kayal, Vizhi G

    2012-01-01

    ABSTRACT The talon cusp is a developmental anomaly characterized by the presence of an accessory cusp like structure projecting from the cingulum area of the anterior teeth. Gemination is an anomaly caused by a single tooth germ that attempted to divide during its development. These developmental anomalies may cause clinical problems including esthetic impairment, pain, caries and tooth crowding. Co-occurrence of two anomalies in a teeth is rare. This paper presents an unusual case of talon cusp on geminated permanent lateral incisor. How to cite this article: Neeraja R, Kayal VG. A Rare Occurrence of Geminated-Taloned Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2012;5(2):136-138. PMID:25206153

  3. A rare occurrence of geminated-taloned maxillary lateral incisor.

    PubMed

    Neeraja, R; Kayal, Vizhi G

    2012-05-01

    The talon cusp is a developmental anomaly characterized by the presence of an accessory cusp like structure projecting from the cingulum area of the anterior teeth. Gemination is an anomaly caused by a single tooth germ that attempted to divide during its development. These developmental anomalies may cause clinical problems including esthetic impairment, pain, caries and tooth crowding. Co-occurrence of two anomalies in a teeth is rare. This paper presents an unusual case of talon cusp on geminated permanent lateral incisor. How to cite this article: Neeraja R, Kayal VG. A Rare Occurrence of Geminated-Taloned Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2012;5(2):136-138. PMID:25206153

  4. Preliminary digital map of cryptocrystalline occurrences in northern Nevada

    USGS Publications Warehouse

    Moyer, Lorre A.

    1999-01-01

    The purpose was to identify potential cryptocrystalline material sources for tools used by indigenous people of the northern Nevada portion of the Great Basin. Cryptocrystalline occurrence data combed from the U.S. Geological Survey's Mineral Resources Data System (MRDS, 1995) were combined with sites described in Nevada rockhound guides and entered into a geographic information system (GIS). The map area encompasses northern Nevada (fig.1). This open-file report describes the methods used to convert cryptocrystalline occurrence data into a digital format, documents the file structures, and explains how to download the digital files from the U.S. Geological Survey's World Wide Web site. Uses of the spatial dataset include, but are not limited to, natural and cultural resource management, interdisciplinary activities, recreational rockhounding, and gold exploration. It is important to note that the accuracy of the spatial data varies widely, and for some purposes, field checks are advised.

  5. Sea ice occurrence predicts genetic isolation in the Arctic fox.

    PubMed

    Geffen, Eli; Waidyaratne, Sitara; Dalén, Love; Angerbjörn, Anders; Vila, Carles; Hersteinsson, Pall; Fuglei, Eva; White, Paula A; Goltsman, Michael; Kapel, Christian M O; Wayne, Robert K

    2007-10-01

    Unlike Oceanic islands, the islands of the Arctic Sea are not completely isolated from migration by terrestrial vertebrates. The pack ice connects many Arctic Sea islands to the mainland during winter months. The Arctic fox (Alopex lagopus), which has a circumpolar distribution, populates numerous islands in the Arctic Sea. In this study, we used genetic data from 20 different populations, spanning the entire distribution of the Arctic fox, to identify barriers to dispersal. Specifically, we considered geographical distance, occurrence of sea ice, winter temperature, ecotype, and the presence of red fox and polar bear as nonexclusive factors that influence the dispersal behaviour of individuals. Using distance-based redundancy analysis and the BIOENV procedure, we showed that occurrence of sea ice is the key predictor and explained 40-60% of the genetic distance among populations. In addition, our analysis identified the Commander and Pribilof Islands Arctic populations as genetically unique suggesting they deserve special attention from a conservation perspective. PMID:17868292

  6. Increased variability of tornado occurrence in the United States.

    PubMed

    Brooks, Harold E; Carbin, Gregory W; Marsh, Patrick T

    2014-10-17

    Whether or not climate change has had an impact on the occurrence of tornadoes in the United States has become a question of high public and scientific interest, but changes in how tornadoes are reported have made it difficult to answer it convincingly. We show that, excluding the weakest tornadoes, the mean annual number of tornadoes has remained relatively constant, but their variability of occurrence has increased since the 1970s. This is due to a decrease in the number of days per year with tornadoes combined with an increase in days with many tornadoes, leading to greater variability on annual and monthly time scales and changes in the timing of the start of the tornado season. PMID:25324388

  7. [Occurrence of indole alkaloids among secondary metabolites of soil Aspergillus].

    PubMed

    Vinokurova, N G; Khmel'nitskaia, I I; Baskunov, B P; Arinbasarov, M U

    2003-01-01

    The occurrence of indole alkaloids among secondary fungal metabolites was studied in species of the genus Aspergillus, isolated from soils that were sampled in various regions of Russia (a total of 102 isolates of the species A. niger, A. phoenicis, A. fumigatus, A. flavus, A. versicolor, A. ustus, A. clavatus, and A. ochraceus). Clavine alkaloids were represented by fumigaclavine, which was formed by A. fumigatus. alpha-Cyclopiazonic acid was formed by isolates of A. fumigatus, A. flavus, A. versicolor, A. phoenicis, and A. clavatus. The occurrence of indole-containing diketopiperazine alkaloids was documented for isolates of A. flavus, A. fumigatus, A. clavatus, and A. ochraceus. No indole-containing metabolites were found among the metabolites of A. ustus or A. niger. PMID:12722658

  8. Occurrence of cohesion of metals during combined plastic deformation

    NASA Technical Reports Server (NTRS)

    Aynbinder, S. G.; Klokova, E. F.

    1980-01-01

    Experiments were conducted to study the cohesion of metals with surface films of varying thickness and hardness. It was established that the deformation necessary for the occurrence of cohesion is determined by the correlation of mechanical properties of the films and the base metal. The greater the relative hardness of the film the lower the deformation necessary for the occurrence of cohesion. The films are as plastic as the base metal prevent cohesion, since in this case it is impossible for sections of metal to appear that are free of contaminants. The physical perculiarities of metals that determine their capability for coalescence under conditions of dry friction are the relative hardness and plasticity of the oxide films formed on their surface under atmospheric conditions.

  9. Formation and occurrence of dopamine-derived betacyanins.

    PubMed

    Kobayashi, N; Schmidt, J; Wray, V; Schliemann, W

    2001-03-01

    In light of the fact that the main betaxanthin (miraxanthin V) and the major betacyanin (2-descarboxy-betanidin) in hairy root cultures of yellow beet (Beta vulgaris L.) are both dopamine-derived, the occurrence of similar structures for the minor betacyanins was also suggested. By HPLC comparison with the betacyanins obtained by dopamine administration to beet seedlings, enzymatic hydrolysis, LCMS and 1H NMR analyses, the minor betacyanins from hairy roots were identified as 2-descarboxy-betanin and its 6'-O-malonyl derivative. A short-term dopamine administration experiment with fodder beet seedlings revealed that the condensation step between 2-descarboxy-cyclo-Dopa and betalamic acid is the decisive reaction, followed by glucosylation and acylation. From these data a pathway for the biosynthesis of dopamine-derived betalains is proposed. Furthermore, the occurrence of these compounds in various cell and hairy root cultures as well as beet plants (Fodder and Garden Beet Group) is shown.

  10. Chronic obstructive pulmonary disease (COPD): factors influencing the occurrence.

    PubMed

    McPherson, E A; Lawson, G H; Murphy, J R; Nicholson, J M; Breeze, R G; Pirie, H M

    1979-07-01

    Breed, age, weight, type of work performed, seasonal onset, poor ventilation and exposure to moulds in the habitat were investigated in relation to the occurrence of chronic obstructive pulmonary disease (COPD). COPD was most commonly detected in showjumping and hacking horses. The older a horse, the more likely it was to become affected although most were 6 to 10 years of age. Of the horses in this sample of the population, which was not a random one, thoroughbred horses were affected least and ponies most often. The high incidence in ponies was related to their more frequent exposure to poor quality fodder and bedding. Most horses are exposed to the hazard of moulds, but more affected horses were so exposed than those not affected with COPD. Poor ventilation of the stable increased the chance of a horse becoming affected. Sex, body weight and season of onset of coughing had no influence on the occurrence of the disease.

  11. Microbiology: detection of bacterial pathogens and their occurrence. [Water pollution

    SciTech Connect

    Reasoner, D.J.

    1982-01-01

    Studies of waterborne diseases are reported in this literature review. Contaminated water is a major source of exposure to bacterial pathogens for both humans and animals. Legionella, an aquatic organism, is of special interest because of its importance as a respiratory pathogen and the human disease outbreaks associated with contaminated air conditioning cooling tower waters and contaminated shower heads in health care institutions. The occurrence and detection of Legionella in water is presented in one of seven tables. Included are 147 references. (JMT)

  12. A simple physical model for deep moonquake occurrence times

    USGS Publications Warehouse

    Weber, R.C.; Bills, B.G.; Johnson, C.L.

    2010-01-01

    The physical process that results in moonquakes is not yet fully understood. The periodic occurrence times of events from individual clusters are clearly related to tidal stress, but also exhibit departures from the temporal regularity this relationship would seem to imply. Even simplified models that capture some of the relevant physics require a large number of variables. However, a single, easily accessible variable - the time interval I(n) between events - can be used to reveal behavior not readily observed using typical periodicity analyses (e.g., Fourier analyses). The delay-coordinate (DC) map, a particularly revealing way to display data from a time series, is a map of successive intervals: I(n+. 1) plotted vs. I(n). We use a DC approach to characterize the dynamics of moonquake occurrence. Moonquake-like DC maps can be reproduced by combining sequences of synthetic events that occur with variable probability at tidal periods. Though this model gives a good description of what happens, it has little physical content, thus providing only little insight into why moonquakes occur. We investigate a more mechanistic model. In this study, we present a series of simple models of deep moonquake occurrence, with consideration of both tidal stress and stress drop during events. We first examine the behavior of inter-event times in a delay-coordinate context, and then examine the output, in that context, of a sequence of simple models of tidal forcing and stress relief. We find, as might be expected, that the stress relieved by moonquakes influences their occurrence times. Our models may also provide an explanation for the opposite-polarity events observed at some clusters. ?? 2010.

  13. Statistical physics approach to earthquake occurrence and forecasting

    NASA Astrophysics Data System (ADS)

    de Arcangelis, Lucilla; Godano, Cataldo; Grasso, Jean Robert; Lippiello, Eugenio

    2016-04-01

    There is striking evidence that the dynamics of the Earth crust is controlled by a wide variety of mutually dependent mechanisms acting at different spatial and temporal scales. The interplay of these mechanisms produces instabilities in the stress field, leading to abrupt energy releases, i.e., earthquakes. As a consequence, the evolution towards instability before a single event is very difficult to monitor. On the other hand, collective behavior in stress transfer and relaxation within the Earth crust leads to emergent properties described by stable phenomenological laws for a population of many earthquakes in size, time and space domains. This observation has stimulated a statistical mechanics approach to earthquake occurrence, applying ideas and methods as scaling laws, universality, fractal dimension, renormalization group, to characterize the physics of earthquakes. In this review we first present a description of the phenomenological laws of earthquake occurrence which represent the frame of reference for a variety of statistical mechanical models, ranging from the spring-block to more complex fault models. Next, we discuss the problem of seismic forecasting in the general framework of stochastic processes, where seismic occurrence can be described as a branching process implementing space-time-energy correlations between earthquakes. In this context we show how correlations originate from dynamical scaling relations between time and energy, able to account for universality and provide a unifying description for the phenomenological power laws. Then we discuss how branching models can be implemented to forecast the temporal evolution of the earthquake occurrence probability and allow to discriminate among different physical mechanisms responsible for earthquake triggering. In particular, the forecasting problem will be presented in a rigorous mathematical framework, discussing the relevance of the processes acting at different temporal scales for different

  14. A STELLAR-MASS-DEPENDENT DROP IN PLANET OCCURRENCE RATES

    SciTech Connect

    Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel

    2015-01-10

    The Kepler spacecraft has discovered a large number of planets with up to one-year periods and down to terrestrial sizes. While the majority of the target stars are main-sequence dwarfs of spectral type F, G, and K, Kepler covers stars with effective temperatures as low as 2500 K, which corresponds to M stars. These cooler stars allow characterization of small planets near the habitable zone, yet it is not clear if this population is representative of that around FGK stars. In this paper, we calculate the occurrence of planets around stars of different spectral types as a function of planet radius and distance from the star and show that they are significantly different from each other. We further identify two trends. First, the occurrence of Earth- to Neptune-sized planets (1-4 R {sub ⊕}) is successively higher toward later spectral types at all orbital periods probed by Kepler; planets around M stars occur twice as frequently as around G stars, and thrice as frequently as around F stars. Second, a drop in planet occurrence is evident at all spectral types inward of a ∼10 day orbital period, with a plateau further out. By assigning to each spectral type a median stellar mass, we show that the distance from the star where this drop occurs is stellar mass dependent, and scales with semi-major axis as the cube root of stellar mass. By comparing different mechanisms of planet formation, trapping, and destruction, we find that this scaling best matches the location of the pre-main-sequence co-rotation radius, indicating efficient trapping of migrating planets or planetary building blocks close to the star. These results demonstrate the stellar-mass dependence of the planet population, both in terms of occurrence rate and of orbital distribution. The prominent stellar-mass dependence of the inner boundary of the planet population shows that the formation or migration of planets is sensitive to the stellar parameters.

  15. Can arsenic occurrence rates in bedrock aquifers be predicted?

    PubMed Central

    Yang, Qiang; Jung, Hun Bok; Marvinney, Robert G.; Culbertson, Charles W.; Zheng, Yan

    2012-01-01

    A high percentage (31%) of groundwater samples from bedrock aquifers in the greater Augusta area, Maine was found to contain greater than 10 µg L−1 of arsenic. Elevated arsenic concentrations are associated with bedrock geology, and more frequently observed in samples with high pH, low dissolved oxygen, and low nitrate. These associations were quantitatively compared by statistical analysis. Stepwise logistic regression models using bedrock geology and/or water chemistry parameters are developed and tested with external data sets to explore the feasibility of predicting groundwater arsenic occurrence rates (the percentages of arsenic concentrations higher than 10 µg L−1) in bedrock aquifers. Despite the under-prediction of high arsenic occurrence rates, models including groundwater geochemistry parameters predict arsenic occurrence rates better than those with bedrock geology only. Such simple models with very few parameters can be applied to obtain a preliminary arsenic risk assessment in bedrock aquifers at local to intermediate scales at other localities with similar geology. PMID:22260208

  16. Statistical modeling of storm-level Kp occurrences

    USGS Publications Warehouse

    Remick, K.J.; Love, J.J.

    2006-01-01

    We consider the statistical modeling of the occurrence in time of large Kp magnetic storms as a Poisson process, testing whether or not relatively rare, large Kp events can be considered to arise from a stochastic, sequential, and memoryless process. For a Poisson process, the wait times between successive events occur statistically with an exponential density function. Fitting an exponential function to the durations between successive large Kp events forms the basis of our analysis. Defining these wait times by calculating the differences between times when Kp exceeds a certain value, such as Kp ??? 5, we find the wait-time distribution is not exponential. Because large storms often have several periods with large Kp values, their occurrence in time is not memoryless; short duration wait times are not independent of each other and are often clumped together in time. If we remove same-storm large Kp occurrences, the resulting wait times are very nearly exponentially distributed and the storm arrival process can be characterized as Poisson. Fittings are performed on wait time data for Kp ??? 5, 6, 7, and 8. The mean wait times between storms exceeding such Kp thresholds are 7.12, 16.55, 42.22, and 121.40 days respectively.

  17. On the Probability of Occurrence of Extreme Space Weather Events

    NASA Technical Reports Server (NTRS)

    Riley, Pete

    2012-01-01

    By virtue of their rarity, extreme space weather events, such as the Carrington event of 1859, are difficult to study, their rates of occurrence are difficult to estimate, and prediction of a specific future event is virtually impossible. Additionally, events may be extreme relative to one parameter but normal relative to others. In this study, we analyze several measures of the severity of space weather events (flare intensity, coronal mass ejection speeds, Dst, and greater than 30 MeV proton fluences as inferred from nitrate records) to estimate the probability of occurrence of extreme events. By showing that the frequency of occurrence scales as an inverse power of the severity of the event, and assuming that this relationship holds at higher magnitudes, we are able to estimate the probability that an event larger than some criteria will occur within a certain interval of time in the future. For example, the probability of another Carrington event (based on Dst less than - 850 nT) occurring within the next decade is approximately 12%. We also identify and address several limitations with this approach. In particular, we assume time stationarity, and thus, the effects of long-term space climate change are not considered. While this technique cannot be used to predict specific events, it may ultimately be useful for probabilistic forecasting.

  18. Can arsenic occurrence rate in bedrock aquifers be predicted?

    USGS Publications Warehouse

    Yang, Qiang; Jung, Hun Bok; Marvinney, Robert G.; Culbertson, Charles W.; Zheng, Yan

    2012-01-01

    A high percentage (31%) of groundwater samples from bedrock aquifers in the greater Augusta area, Maine was found to contain greater than 10 μg L–1 of arsenic. Elevated arsenic concentrations are associated with bedrock geology, and more frequently observed in samples with high pH, low dissolved oxygen, and low nitrate. These associations were quantitatively compared by statistical analysis. Stepwise logistic regression models using bedrock geology and/or water chemistry parameters are developed and tested with external data sets to explore the feasibility of predicting groundwater arsenic occurrence rates (the percentages of arsenic concentrations higher than 10 μg L–1) in bedrock aquifers. Despite the under-prediction of high arsenic occurrence rates, models including groundwater geochemistry parameters predict arsenic occurrence rates better than those with bedrock geology only. Such simple models with very few parameters can be applied to obtain a preliminary arsenic risk assessment in bedrock aquifers at local to intermediate scales at other localities with similar geology.

  19. Occurrence of priority organic pollutants in the fertilizers, China.

    PubMed

    Mo, Ce-Hui; Cai, Quan-Ying; Li, Yun-Hui; Zeng, Qiao-Yun

    2008-04-15

    The use of large quantities of chemical fertilizers is usually associated with environmental problems. A lot of work has been done on the concentrations of heavy metals and radionuclides in chemical fertilizers, but little work has focused on the occurrence of semi-volatile organic compounds (SVOCs). In this study the occurrence of 43 SVOCs listed as priority pollutants in 22 widely used-fertilizers of China was determined by gas chromatography coupled with mass spectrometry. Twenty-six SVOCs were detected with different detection frequencies and concentrations. The most abundant compounds were phthalic acid esters (PAEs; ranging from 1.17 to 2795 microg kg(-1) dry weight, d.w.) and nitroaromatics (up to 9765 microg kg(-1) d.w.), followed by polycyclic aromatic hydrocarbons (PAHs; <140 microg kg(-1) d.w.) and halogenated hydrocarbons (<900 microg kg(-1) d.w.). Chlorobenzenes and haloethers occurred generally at low concentrations. There are large variations in concentrations of various compounds in different fertilizers, and the total concentrations of each class of contaminants varied widely, too. The highest levels of sum concentration for 16 PAHs, for 6 PAEs and for nitroaromatics were found in organic fertilizer containing pesticide and soil amendments. Concentrations of SVOCs in coated fertilizers (the controlled release fertilizer with coating) were considerably higher than those in the corresponding fertilizers without coating. The occurrence frequencies of SVOCs in the straight fertilizers (containing only one of the major plant nutrients) were lower than in the other fertilizers. PMID:17826902

  20. Correlates of vernal pool occurrence in the Massachusetts USA, landscape

    USGS Publications Warehouse

    Grant, E.H.C.

    2005-01-01

    Vernal pool wetlands are at risk of destruction across the northeast United States, due in part to their diminutive size and short hydroperiods. These characteristics make it difficult to locate vernal pool habitats in the landscape during much of the year, and no efficient method exists for predicting their occurrence. A logistic regression procedure was used to identify large-scale variables that influence the presence of a potential vernal pool, including surficial geology, land use and land cover, soil classification, topography, precipitation, and surficial hydrologic features. The model was validated with locations of field-verified vernal pools. The model demonstrated that the probability of potential vernal pool occurrence is positively related to slope, negatively related to till/bedrock surficial geology, and negatively related to the proportion of cropland, urban/commercial, and high density residential development in the landscape. The relationship between vernal pool occurrence and large-scale variables suggests that these habitats do not occur at random in the landscape, and thus, protection in situ should be considered.

  1. Occurrence of priority organic pollutants in the fertilizers, China.

    PubMed

    Mo, Ce-Hui; Cai, Quan-Ying; Li, Yun-Hui; Zeng, Qiao-Yun

    2008-04-15

    The use of large quantities of chemical fertilizers is usually associated with environmental problems. A lot of work has been done on the concentrations of heavy metals and radionuclides in chemical fertilizers, but little work has focused on the occurrence of semi-volatile organic compounds (SVOCs). In this study the occurrence of 43 SVOCs listed as priority pollutants in 22 widely used-fertilizers of China was determined by gas chromatography coupled with mass spectrometry. Twenty-six SVOCs were detected with different detection frequencies and concentrations. The most abundant compounds were phthalic acid esters (PAEs; ranging from 1.17 to 2795 microg kg(-1) dry weight, d.w.) and nitroaromatics (up to 9765 microg kg(-1) d.w.), followed by polycyclic aromatic hydrocarbons (PAHs; <140 microg kg(-1) d.w.) and halogenated hydrocarbons (<900 microg kg(-1) d.w.). Chlorobenzenes and haloethers occurred generally at low concentrations. There are large variations in concentrations of various compounds in different fertilizers, and the total concentrations of each class of contaminants varied widely, too. The highest levels of sum concentration for 16 PAHs, for 6 PAEs and for nitroaromatics were found in organic fertilizer containing pesticide and soil amendments. Concentrations of SVOCs in coated fertilizers (the controlled release fertilizer with coating) were considerably higher than those in the corresponding fertilizers without coating. The occurrence frequencies of SVOCs in the straight fertilizers (containing only one of the major plant nutrients) were lower than in the other fertilizers.

  2. Can arsenic occurrence rates in bedrock aquifers be predicted?

    PubMed

    Yang, Qiang; Jung, Hun Bok; Marvinney, Robert G; Culbertson, Charles W; Zheng, Yan

    2012-02-21

    A high percentage (31%) of groundwater samples from bedrock aquifers in the greater Augusta area, Maine was found to contain greater than 10 μg L(-1) of arsenic. Elevated arsenic concentrations are associated with bedrock geology, and more frequently observed in samples with high pH, low dissolved oxygen, and low nitrate. These associations were quantitatively compared by statistical analysis. Stepwise logistic regression models using bedrock geology and/or water chemistry parameters are developed and tested with external data sets to explore the feasibility of predicting groundwater arsenic occurrence rates (the percentages of arsenic concentrations higher than 10 μg L(-1)) in bedrock aquifers. Despite the under-prediction of high arsenic occurrence rates, models including groundwater geochemistry parameters predict arsenic occurrence rates better than those with bedrock geology only. Such simple models with very few parameters can be applied to obtain a preliminary arsenic risk assessment in bedrock aquifers at local to intermediate scales at other localities with similar geology.

  3. THE OCCURRENCE RATE OF SMALL PLANETS AROUND SMALL STARS

    SciTech Connect

    Dressing, Courtney D.; Charbonneau, David

    2013-04-10

    We use the optical and near-infrared photometry from the Kepler Input Catalog to provide improved estimates of the stellar characteristics of the smallest stars in the Kepler target list. We find 3897 dwarfs with temperatures below 4000 K, including 64 planet candidate host stars orbited by 95 transiting planet candidates. We refit the transit events in the Kepler light curves for these planet candidates and combine the revised planet/star radius ratios with our improved stellar radii to revise the radii of the planet candidates orbiting the cool target stars. We then compare the number of observed planet candidates to the number of stars around which such planets could have been detected in order to estimate the planet occurrence rate around cool stars. We find that the occurrence rate of 0.5-4 R{sub Circled-Plus} planets with orbital periods shorter than 50 days is 0.90{sup +0.04}{sub -0.03} planets per star. The occurrence rate of Earth-size (0.5-1.4 R{sub Circled-Plus }) planets is constant across the temperature range of our sample at 0.51{sub -0.05}{sup +0.06} Earth-size planets per star, but the occurrence of 1.4-4 R{sub Circled-Plus} planets decreases significantly at cooler temperatures. Our sample includes two Earth-size planet candidates in the habitable zone, allowing us to estimate that the mean number of Earth-size planets in the habitable zone is 0.15{sup +0.13}{sub -0.06} planets per cool star. Our 95% confidence lower limit on the occurrence rate of Earth-size planets in the habitable zones of cool stars is 0.04 planets per star. With 95% confidence, the nearest transiting Earth-size planet in the habitable zone of a cool star is within 21 pc. Moreover, the nearest non-transiting planet in the habitable zone is within 5 pc with 95% confidence.

  4. A compilation of mineral occurrences and the relationship of occurrences to structural elements of the Kentucky and Tennessee region

    NASA Technical Reports Server (NTRS)

    Mayhew, M. A.; Myers, D. M.

    1984-01-01

    A very prominent magnetic anomaly measured by MAGSAT over the eastern mid-continent of the United States was inferred to have a source region beneath Kentucky and Tennessee. Prominent aeromagnetic and gravity anomalies are also associated with the inferred source region. A crustal model constructed to fit these anomalies interpreted the complex as a large mafic plutonic intrusion of Precambrian age. The complex was named the Kentucky body. It was noticed that the Jessamine Dome, which is a locus of intense faulting and mineralization, occurs near the northern end of the Kentucky body, and that more generally there seemed to be a spatial relationship between mineral occurrence and the body. The relationship between mineral deposits in Kentucky and Tennessee and the Kentucky body was investigated. A compilation of mineral occurrences in the region, classified according to type and age, is presented.

  5. OCCURRENCE OF Blastocystis spp. IN UBERABA, MINAS GERAIS, BRAZIL.

    PubMed

    Cabrine-Santos, Marlene; Cintra, Eduardo do Nascimento; do Carmo, Rafaela Andrade; Nascentes, Gabriel Antônio Nogueira; Pedrosa, André Luiz; Correia, Dalmo; Oliveira-Silva, Márcia Benedita de

    2015-01-01

    Intestinal parasites are a problem for public health all over the world. The infection with Blastocystis, a protozoan of controversial pathogenicity, is one of the most common among them all. In this study, the occurrence of intestinal parasites, with emphasis on Blastocystis, in patients at the Universidade Federal do Triângulo Mineiro was investigated in Uberaba (MG) through microscopy of direct smears and fecal concentrates using Ritchie's method. Feces of 1,323 patients were examined from April 2011 to May 2012. In 28.7% of them at least one intestinal parasite was identified, and the most frequent organisms were Blastocystis spp. (17.8%) and Giardia intestinalis (7.4%). The occurrence of parasitism was higher in children aged 6 -10 years old, and the infection with Blastocystis spp. was higher above the age of six (p < 0.001). The exclusive presence of G. intestinalis and of Blastocystis spp. was observed in 5.4% and 12.2% of the patients, respectively. Regarding patients with diarrheic feces, 8% revealed unique parasitism of Blastocystis spp. Other intestinal parasites observed in children were Ascaris lumbricoides (0.3%) and Entamoeba histolytica/dispar/moshkovskii (1.4%). The Ritchie's method was more sensitive (92.8%) when compared to direct microscopy (89.8%), with high agreement between them (97.7%, kappa = 0.92). In conclusion, the occurrence of Blastocystis spp. in Uberaba is high and the presence of diarrheic feces with exclusive presence of the parasite of Blastocystis spp. was observed. PMID:26200960

  6. OCCURRENCE OF Blastocystis spp. IN UBERABA, MINAS GERAIS, BRAZIL

    PubMed Central

    CABRINE-SANTOS, Marlene; CINTRA, Eduardo do Nascimento; do CARMO, Rafaela Andrade; NASCENTES, Gabriel Antônio Nogueira; PEDROSA, André Luiz; CORREIA, Dalmo; de OLIVEIRA-SILVA, Márcia Benedita

    2015-01-01

    Intestinal parasites are a problem for public health all over the world. The infection with Blastocystis, a protozoan of controversial pathogenicity, is one of the most common among them all. In this study, the occurrence of intestinal parasites, with emphasis on Blastocystis, in patients at the Universidade Federal do Triângulo Mineiro was investigated in Uberaba (MG) through microscopy of direct smears and fecal concentrates using Ritchie’s method. Feces of 1,323 patients were examined from April 2011 to May 2012. In 28.7% of them at least one intestinal parasite was identified, and the most frequent organisms were Blastocystis spp. (17.8%) and Giardia intestinalis (7.4%). The occurrence of parasitism was higher in children aged 6 -10 years old, and the infection with Blastocystis spp. was higher above the age of six (p < 0.001). The exclusive presence of G. intestinalis and of Blastocystis spp. was observed in 5.4% and 12.2% of the patients, respectively. Regarding patients with diarrheic feces, 8% revealed unique parasitism of Blastocystis spp. Other intestinal parasites observed in children were Ascaris lumbricoides(0.3%) and Entamoeba histolytica/dispar/moshkovskii (1.4%). The Ritchie’s method was more sensitive (92.8%) when compared to direct microscopy (89.8%), with high agreement between them (97.7%, kappa = 0.92). In conclusion, the occurrence of Blastocystis spp. in Uberaba is high and the presence of diarrheic feces with exclusive presence of the parasite of Blastocystis spp. was observed. PMID:26200960

  7. The occurrence of Naegleria fowleri in recreational waters in Arizona.

    PubMed

    Sifuentes, Laura Y; Choate, Brittany L; Gerba, Charles P; Bright, Kelly R

    2014-09-19

    Naegleria fowleri is a free-living amoeba found in waters in warmer regions that causes primary amoebic meningoencephalitis, a rare but almost universally fatal disease. The goal of this project was to assess the occurrence of N. fowleri and other thermophilic amoebae in 33 recreational surface waters across Arizona to determine if their presence could be correlated with seasonal or other environmental factors. First, 1-L grab samples were collected over two years and analyzed using polymerase chain reaction and amoebae viability. Seasonality was observed, with N. fowleri and thermophilic amoebae (20% and 30%, respectively) being detected more often in the winter and spring combined than in the summer and fall combined (7.9% and 9.5%, respectively). The spring and fall both had an average temperature of 18°C, yet had different occurrence data (18.2% versus 5.9% for N. fowleri, respectively; 27.3% versus 0% for viable amoebae, respectively). These results are in stark contrast to previous studies in which N. fowleri has been found almost exclusively during warmer months. Over the two-year study, N. fowleri was detected in six and thermophilic amoebae in eight of the 33 recreational water bodies. Five of these were lakes near Phoenix that tested positive for N. fowleri and thermophilic amoebae over multiple seasons. These lakes differed significantly (P ≤ 0.05) from the other 28 surface waters, with a lower average temperature in the spring, a higher temperature in the fall, a higher pH and turbidity in the summer, and a lower electro-conductivity in the spring. They also had lower Escherichia coli and heterotrophic bacteria levels during colder months. Future N. fowleri monitoring in Arizona should focus on these five lakes to further elucidate the factors that contribute to the low occurrence of this amoeba in the summer or which might explain why these lakes appear to be reservoirs for the organism. PMID:24967566

  8. Global distributions and occurrence rates of transient luminous events

    NASA Astrophysics Data System (ADS)

    Chen, Alfred B.; Kuo, Cheng-Ling; Lee, Yi-Jen; Su, Han-Tzong; Hsu, Rue-Ron; Chern, Jyh-Long; Frey, Harald U.; Mende, Stephen B.; Takahashi, Yukihiro; Fukunishi, Hiroshi; Chang, Yeou-Shin; Liu, Tie-Yue; Lee, Lou-Chuang

    2008-08-01

    We report the global transient luminous event (TLE) distributions and rates based on the Imager of Sprites and Upper Atmospheric Lightning (ISUAL) experiment onboard the FORMOSAT-2 satellite. ISUAL observations cover 45°S to 25°N latitude during the northern summer and 25°S to 45°N latitude during the northern winter. From July 2004 to June 2007, ISUAL recorded 5,434 elves, 633 sprites, 657 halos, and 13 gigantic jets. Surprisingly, elve is the dominant type of TLEs, while sprites/halos are a distant second. Elve occurrence rate jumps as the sea surface temperature exceeds 26 degrees Celsius, manifesting an ocean-atmosphere-ionosphere coupling. In the ISUAL survey, elves concentrate over the Caribbean Sea, South China Sea, east Indian Ocean, central Pacific Ocean, west Atlantic Ocean, and southwest Pacific Ocean; while sprites congregate over central Africa, Japan Sea, and west Atlantic Ocean. The ISUAL experiment observed global rates of 3.23, 0.50, 0.39, and 0.01 events per minute for elves, sprites, halos, and gigantic jets, respectively. Taking the instrumental detection sensitivity and the restricted survey area into account, the corrected global occurrence rates for sprites and elves likely are a factor of two and an order of magnitude higher, respectively. ISUAL observations also indicate that the relative frequency of high peak current lightning (>80 kA) is 10 times higher over the oceans than over the land. On the basis of the corrected ISUAL elve global occurrence rate, the total electron content at the lower ionosphere above elve hot zones was computed to be elevated by more than 5%.

  9. The occurrence of Naegleria fowleri in recreational waters in Arizona.

    PubMed

    Sifuentes, Laura Y; Choate, Brittany L; Gerba, Charles P; Bright, Kelly R

    2014-09-19

    Naegleria fowleri is a free-living amoeba found in waters in warmer regions that causes primary amoebic meningoencephalitis, a rare but almost universally fatal disease. The goal of this project was to assess the occurrence of N. fowleri and other thermophilic amoebae in 33 recreational surface waters across Arizona to determine if their presence could be correlated with seasonal or other environmental factors. First, 1-L grab samples were collected over two years and analyzed using polymerase chain reaction and amoebae viability. Seasonality was observed, with N. fowleri and thermophilic amoebae (20% and 30%, respectively) being detected more often in the winter and spring combined than in the summer and fall combined (7.9% and 9.5%, respectively). The spring and fall both had an average temperature of 18°C, yet had different occurrence data (18.2% versus 5.9% for N. fowleri, respectively; 27.3% versus 0% for viable amoebae, respectively). These results are in stark contrast to previous studies in which N. fowleri has been found almost exclusively during warmer months. Over the two-year study, N. fowleri was detected in six and thermophilic amoebae in eight of the 33 recreational water bodies. Five of these were lakes near Phoenix that tested positive for N. fowleri and thermophilic amoebae over multiple seasons. These lakes differed significantly (P ≤ 0.05) from the other 28 surface waters, with a lower average temperature in the spring, a higher temperature in the fall, a higher pH and turbidity in the summer, and a lower electro-conductivity in the spring. They also had lower Escherichia coli and heterotrophic bacteria levels during colder months. Future N. fowleri monitoring in Arizona should focus on these five lakes to further elucidate the factors that contribute to the low occurrence of this amoeba in the summer or which might explain why these lakes appear to be reservoirs for the organism.

  10. Predicting typology of landslide occurrences by statistical GIS analysis

    NASA Astrophysics Data System (ADS)

    Mancini, Francesco; Ceppi, Claudia; Ritrovato, Giuliano

    2010-05-01

    This study aim at the landslide susceptibility mapping by multivariate statistical methods with the additional capability to distinguish among typology of landslide occurrences. The methodology is being tested in a hilly area of the Daunia Region (Apulia, southern Italy) where small settlements are historically threatened by landslide phenomena. In the used multivariate statistical analysis all the variables were managed in a GIS in addition to the landslide inventory where geometric and descriptive properties have to be implemented in a suitable data structure in order to refer the independent set of variables to the typology of landslide occurrences. The independent set of variable selected as possible triggering factors of slope instability phenomena are: elevation, slope, aspect, planform and profile curvature, drained area, lithology, land use, distance from road and river network. The implementation of the landslide inventory was more demanding with respect to a usual multivariate analysis, such as the multiple regression analysis, where the simple presence/absence status of occurrences is being required. According to the classification proposed by Cruden and Varnes, three main landslide typologies were included in the inventory after recognizing by geomorphological survey: a) intermediate to deep-seated compound landslides with failure surface depth > 30m; b) mudslides of shallow to intermediate depth sliding surface; c) deep-seated to intermediate depth rotational landslides with depth of sliding surface < 30m. The inventory implementation constitutes a significant effort supported by the project "Landslide risk assessment for the planning of small urban settlements within chain areas: the case of Daunia" through several expertise. The outcomes of the analysis provide the proneness to landslide, as predicted level of probability, by considering in addition the failure mechanism introduced in the landslide inventory. A map of landslide susceptibility along

  11. Prediction of Periventricular Leukomalacia Occurrence in Neonates After Heart Surgery

    PubMed Central

    Jalali, Ali; Buckley, Erin M.; Lynch, Jennifer M.; Schwab, Peter J.; Licht, Daniel J.; Nataraj, C

    2014-01-01

    This paper is concerned with predicting the occurrence of Periventricular Leukomalacia (PVL) using vital and blood gas data which are collected over a period of twelve hours after neonatal cardiac surgery. A data mining approach has been employed to generate a set of rules for classification of subjects as healthy or PVL affected. In view of the fact that blood gas and vital data have different sampling rates, in this study we have divided the data into two categories: (i) high resolution (vital), and (ii) low resolution (blood gas), and designed a separate classifier based on each data category. The developed algorithm is composed of several stages; first, a feature pool has been extracted from each data category and the extracted features have been ranked based on the data reliability and their mutual information content with the output. An optimal feature subset with the highest discriminative capability has been formed using simultaneous maximization of the class separability measure and mutual information of a set. Two separate decision trees (DT) have been developed for the classification purpose and more importantly to discover hidden relationships that exist among the data to help us better understand PVL pathophysiology. The DT result shows that high amplitude twenty minute variations and low sample entropy in the vital data and the defined out of range index as well as maximum rate of change in blood gas data are important factors for PVL prediction. Low sample entropy represents lack of variability in hemodynamic measurement, and constant blood pressure with small fluctuations is an important indicator of PVL occurrence. Finally, using the different time frames of data collection, we show that the first six hours of data contain sufficient information for PVL occurrence prediction. PMID:24122606

  12. Phyllostomid bat occurrence in successional stages of neotropical dry forests.

    PubMed

    Avila-Cabadilla, Luis Daniel; Stoner, Kathryn Elizabeth; Nassar, Jafet M; Espírito-Santo, Mario M; Alvarez-Añorve, Mariana Yolotl; Aranguren, Carla I; Henry, Mickael; González-Carcacía, José A; Dolabela Falcão, Luiz A; Sanchez-Azofeifa, Gerardo Arturo

    2014-01-01

    Tropical dry forests (TDFs) are highly endangered tropical ecosystems being replaced by a complex mosaic of patches of different successional stages, agricultural fields and pasturelands. In this context, it is urgent to understand how taxa playing critical ecosystem roles respond to habitat modification. Because Phyllostomid bats provide important ecosystem services (e.g. facilitate gene flow among plant populations and promote forest regeneration), in this study we aimed to identify potential patterns on their response to TDF transformation in sites representing four different successional stages (initial, early, intermediate and late) in three Neotropical regions: México, Venezuela and Brazil. We evaluated bat occurrence at the species, ensemble (abundance) and assemblage level (species richness and composition, guild composition). We also evaluated how bat occurrence was modulated by the marked seasonality of TDFs. In general, we found high seasonal and regional specificities in phyllostomid occurrence, driven by specificities at species and guild levels. For example, highest frugivore abundance occurred in the early stage of the moistest TDF, while highest nectarivore abundance occurred in the same stage of the driest TDF. The high regional specificity of phyllostomid responses could arise from: (1) the distinctive environmental conditions of each region, (2) the specific behavior and ecological requirements of the regional bat species, (3) the composition, structure and phenological patterns of plant assemblages in the different stages, and (4) the regional landscape composition and configuration. We conclude that, in tropical seasonal environments, it is imperative to perform long-term studies considering seasonal variations in environmental conditions and plant phenology, as well as the role of landscape attributes. This approach will allow us to identify potential patterns in bat responses to habitat modification, which constitute an invaluable tool for

  13. Phyllostomid Bat Occurrence in Successional Stages of Neotropical Dry Forests

    PubMed Central

    Avila-Cabadilla, Luis Daniel; Stoner, Kathryn Elizabeth; Nassar, Jafet M.; Espírito-Santo, Mario M.; Alvarez-Añorve, Mariana Yolotl; Aranguren, Carla I.; Henry, Mickael; González-Carcacía, José A.; Dolabela Falcão, Luiz A.; Sanchez-Azofeifa, Gerardo Arturo

    2014-01-01

    Tropical dry forests (TDFs) are highly endangered tropical ecosystems being replaced by a complex mosaic of patches of different successional stages, agricultural fields and pasturelands. In this context, it is urgent to understand how taxa playing critical ecosystem roles respond to habitat modification. Because Phyllostomid bats provide important ecosystem services (e.g. facilitate gene flow among plant populations and promote forest regeneration), in this study we aimed to identify potential patterns on their response to TDF transformation in sites representing four different successional stages (initial, early, intermediate and late) in three Neotropical regions: México, Venezuela and Brazil. We evaluated bat occurrence at the species, ensemble (abundance) and assemblage level (species richness and composition, guild composition). We also evaluated how bat occurrence was modulated by the marked seasonality of TDFs. In general, we found high seasonal and regional specificities in phyllostomid occurrence, driven by specificities at species and guild levels. For example, highest frugivore abundance occurred in the early stage of the moistest TDF, while highest nectarivore abundance occurred in the same stage of the driest TDF. The high regional specificity of phyllostomid responses could arise from: (1) the distinctive environmental conditions of each region, (2) the specific behavior and ecological requirements of the regional bat species, (3) the composition, structure and phenological patterns of plant assemblages in the different stages, and (4) the regional landscape composition and configuration. We conclude that, in tropical seasonal environments, it is imperative to perform long-term studies considering seasonal variations in environmental conditions and plant phenology, as well as the role of landscape attributes. This approach will allow us to identify potential patterns in bat responses to habitat modification, which constitute an invaluable tool for

  14. Occurrence and Control of Legionella in Recycled Water Systems.

    PubMed

    Jjemba, Patrick K; Johnson, William; Bukhari, Zia; LeChevallier, Mark W

    2015-01-01

    Legionella pneumophila is on the United States Environmental Protection Agency (USEPA) Candidate Contaminant list (CCL) as an important pathogen. It is commonly encountered in recycled water and is typically associated with amoeba, notably Naegleria fowleri (also on the CCL) and Acanthamoeba sp. No legionellosis outbreak has been linked to recycled water and it is important for the industry to proactively keep things that way. A review was conducted examine the occurrence of Legionella and its protozoa symbionts in recycled water with the aim of developing a risk management strategy. The review considered the intricate ecological relationships between Legionella and protozoa, methods for detecting both symbionts, and the efficacy of various disinfectants. PMID:26140674

  15. The relationship of headache occurrence to barometric pressure

    NASA Astrophysics Data System (ADS)

    Schulman, Jane; Leviton, A.; Slack, W.; Porter, D.; Graham, J. R.

    1980-09-01

    A total of 75 people residing in the metropolitan Boston area who had frequently recurring headaches kept a headache diary for one month beginning March 1975. Data were also collected about barometric pressure during this time. We found that the probability of headache severity on any day was independent of the effects of time. An inference of this, supported by other findings in this study, is that headache occurrence is minimally affected by time-related phenomena such as barometric pressure readings or changes..

  16. The occurrence and transport of radon in the natural environment

    NASA Astrophysics Data System (ADS)

    Reimer, G. M.

    1990-05-01

    Radon—a colorless, odorless, tasteless, radioactive gas known to accumulate in homes. Within the last two years, those words have appeared in probably every newspaper in the country, informing the public that they may have an increased risk of lung cancer due to exposure to radon. Although the actual health risks of the slightly elevated concentrations found in the vast majority of homes is a matter of current scientific study, there are clearly some areas of the country where indoor levels and individual exposures can approach those found in underground mines. In these cases, the risks are not in doubt, but questions concerning the occurrence and transport of radon abound.

  17. A Statistical Analysis of Term Occurrences in Radiology Reporting.

    PubMed

    Hong, Yi; Zhang, Jin; Zhu, Ying; Zhou, Xiaoying

    2015-01-01

    To compare term occurrences in free-text radiology reports and RSNA reporting templates, we selected five templates from an RSNA reporting template library and their corresponding free-text reports as a test set, and employed the Wilcoxon signed-rank test to find out whether the terms in RSNA reporting templates match those terms appearing in corresponding free-text radiology reports. The results show that most terms in free-text radiology reports are covered by RSNA reporting templates. By assessing the terminology coverage of existing templates, this study may benefit the growth of the RSNA reporting template library. PMID:26262384

  18. The occurrence of denitrification in extremely halophilic bacteria

    NASA Technical Reports Server (NTRS)

    Mancinelli, R. L.; Hochstein, L. I.

    1986-01-01

    The ability of Halobacterium vallismortis, Halobacterium mediterranei and Halobacterium marismortui (Ginzburg strain) to grow anaerobically and denitrify was determined. Each organism grew anaerobically only in the presence of nitrate. H. marismortui produced nitrite and dinitrogen from nitrate during exponential growth. However, as the culture entered stationary phase, dinitrogen production ceased and nitrous oxide was detected. H. vallismortis produced nitrous oxide and dinitrogen during exponential growth, with dinitrogen production ceasing at the onset of stationary phase. H. mediterranei produced dinitrogen during exponential growth and did not produce nitrous oxide. These results confirm the occurrence of denitrification in the halobacteria.

  19. Microplastics in sediments: A review of techniques, occurrence and effects.

    PubMed

    Van Cauwenberghe, Lisbeth; Devriese, Lisa; Galgani, François; Robbens, Johan; Janssen, Colin R

    2015-10-01

    Microplastics are omnipresent in the marine environment and sediments are hypothesized to be major sinks of these plastics. Here, over 100 articles spanning the last 50 year are reviewed with following objectives: (i) to evaluate current microplastic extraction techniques, (ii) to discuss the occurrence and worldwide distribution of microplastics in sediments, and (iii) to make a comprehensive assessment of the possible adverse effects of this type of pollution to marine organisms. Based on this review we propose future research needs and conclude that there is a clear need for a standardized techniques, unified reporting units and more realistic effect assessments.

  20. Occurrence of ungulic acid in some epidermal tissues.

    PubMed

    Leikola, E; Nieminen, E; Teppo, A M

    1970-07-01

    The lipids isolated from different animal tissues have been studied qualitatively, by TLC, for the occurrence of the ungulic acid fraction. This fraction was found in considerable amounts only in epidermal tissues and its keratinized derivatives. In the present study it was isolated from human keratinous epidermis, hair, and nails, pig bristles, wool, and feathers. The analytical results indicated that a lipid fraction from all of these sources contained ceramide, galactose, galactosamine, sulfate, and sialic acid in equimolar amounts, and that the fractions were similar to the ungulic acid isolated earlier from a horse's hoof.

  1. Occurrence of pesticide residues in Lebanon's water resources.

    PubMed

    Kouzayha, Abir; Al Ashi, Aisha; Al Akoum, Rami; Al Iskandarani, Mohamad; Budzinski, Hélène; Jaber, Farouk

    2013-11-01

    Contamination of water sources by pesticides is one of the most critical environmental problems. The present work is designed to address the occurrence of 67 pesticides in the Lebanese waters. Chemical analysis was performed by a solid-phase extraction followed by a gas chromatography-mass spectrometry using programmed temperature vaporization injection. In drinking water and groundwater samples, organochlorine and organophosphate pesticides were frequently detected with a maximal sum concentration of up to 31.8 ng L(-1). High pesticide ecotoxicological risk was noticed in many surface waters, while this risk was driven mainly by diazinon, chlorpyrifos, fenpropathrin and bifenthrin insecticides.

  2. Food ellagitannins-occurrence, effects of processing and storage.

    PubMed

    Bakkalbaşi, Emre; Menteş, Ozay; Artik, Nevzat

    2009-03-01

    Interest in ellagitannins and ellagic acid has increased over the past few years due to its properties as a micronutrient. Ellagitannins are complex plant polyphenols composed of hexahydroxydiphenoyl moieties esterified to a sugar. Fruits (especially berries and nuts) are rich sources of ellagitannins and ellagic acid, a hydrolytic product of ellagitannins. These secondary metabolites give the characteristic taste to the fruits and their products, and also play an important role in food processing. This paper reviews research about occurrence in foods, change during process, and antioxidant activity of ellagitannins and ellagic acid. PMID:19093271

  3. The paleogeographic significance of Aquilapollenites occurrence in Pakistan

    NASA Astrophysics Data System (ADS)

    Khan, Asrar M.; Srivastava, Satish K.

    2006-12-01

    The occurrence of the genus Aquilapollenites in Upper Cretaceous and Neogene sediments of northwestern Pakistan is reported here. Aquilapollenites amplus, Aquilapollenites reductus, and Aquilapollenites sp. occur in the Maastrichtian palynomorph assemblage from an outcrop sample of the Mir Ali section, northern Waziristan. Aquilapollenites medeis in the Neogene Murgha Faqir Zai Formation of the Pishin Basin, Balochistan, is considered a reworked Cretaceous specimen. The Upper Cretaceous sediments of the Asian plate on the Tethys margin are considered to be the source of Aquilapollenites spp. in these samples.

  4. The occurrence of gonadal dysgenesis in association with monozygotic twinning.

    PubMed Central

    Karp, L; Bryant, J I; Tagatz, G; Giblett, E; Fialkow, P J

    1975-01-01

    A case is presented of a monozygotic twin pair, discordant for phenotypic sex, in which the female member showed gonadal dysgenesis and chromosomal mosaicism. Review of the pertinent literature reveals that in monozygotic twin pairs, phenotypic and karyotypic concordance is the usual occurrence for Down's and Klinefelter's syndromes, whereas discordance often accompanies gonadal dysgenesis. Mosaicism is a frequent concomitant of gonadal dysgenesis in monozygotic twins. Our case strengthens the probability of a real association between mosaicism and monozygotic twinning in gonadal dysgenesis. Images PMID:1121022

  5. Occurrence and Control of Legionella in Recycled Water Systems

    PubMed Central

    Jjemba, Patrick K.; Johnson, William; Bukhari, Zia; LeChevallier, Mark W.

    2015-01-01

    Legionella pneumophila is on the United States Environmental Protection Agency (USEPA) Candidate Contaminant list (CCL) as an important pathogen. It is commonly encountered in recycled water and is typically associated with amoeba, notably Naegleria fowleri (also on the CCL) and Acanthamoeba sp. No legionellosis outbreak has been linked to recycled water and it is important for the industry to proactively keep things that way. A review was conducted examine the occurrence of Legionella and its protozoa symbionts in recycled water with the aim of developing a risk management strategy. The review considered the intricate ecological relationships between Legionella and protozoa, methods for detecting both symbionts, and the efficacy of various disinfectants. PMID:26140674

  6. Occurrence probability of structured motifs in random sequences.

    PubMed

    Robin, S; Daudin, J-J; Richard, H; Sagot, M-F; Schbath, S

    2002-01-01

    The problem of extracting from a set of nucleic acid sequences motifs which may have biological function is more and more important. In this paper, we are interested in particular motifs that may be implicated in the transcription process. These motifs, called structured motifs, are composed of two ordered parts separated by a variable distance and allowing for substitutions. In order to assess their statistical significance, we propose approximations of the probability of occurrences of such a structured motif in a given sequence. An application of our method to evaluate candidate promoters in E. coli and B. subtilis is presented. Simulations show the goodness of the approximations. PMID:12614545

  7. Familial Occurrence of Enteric Muco-Submucosal Elongated Polyp

    PubMed Central

    Nakamura, Kenji; Okamoto, Takeshi; Imamura, Noriatsu; Ishii, Naoki; Fujita, Yoshiyuki

    2016-01-01

    We report 2 cases of enteric muco-submucosal elongated polyps (EMSEPs) that presented with gastrointestinal bleeding. The 2 patients are siblings. They both had a history of percutaneous coronary intervention for coronary artery disease and were on dual antiplatelet therapy. They underwent endoscopic resection of the polyps, which displayed identical endoscopic and histological features compatible with EMSEP. This is the first report of familial occurrence of EMSEP, suggesting possible genetic involvement. It is also important to note that the use of antiplatelet agents appears to be a predisposing factor for gastrointestinal bleeding from EMSEP. PMID:27807549

  8. Toxic Substances from Coal Combustion - Forms of Occurrence Analyses

    SciTech Connect

    Allan Kolker; Curtis A. Palmer; Harvey E. Belkin; Jason Willet; Kathleen C. Kolb; Robert B. Finkelman; Sharon S. Crowley; Stanley J. Mroczkowski

    1998-12-14

    In a cooperative agreement with DOE (Contract No. DE- AC22- 95101), the USGS has participated with Physical Sciences, Inc. (PSI) in a project entitled "Toxic Substances From Coal Combustion -A Comprehensive Assessment". Samples from the Pittsburgh, Elkhorn/ Hazard, Illinois No. 6, and Wyodak program coals were examined to determine the mode of occurrence of selected trace elements (As, Se, Cr, Hg, and Ni) using selective leaching, scanning electron microscopy, electron microprobe analysis, and X- ray diffraction techniques. Among other findings, our results indicate that the bulk of the arsenic in the Pittsburgh and Illinois No. 6 coals is in pyrite. High percentages (60- 80%) of arsenic were leached by nitric acid, and microprobe data confirm the presence of arsenic in pyrite in each of these coals (concentrations ranging from <0.01 to 0.09 wt.% of the pyrite grains). In the Elkhorn/ Hazard coal, arsenic may have several modes of occurrences. About 30 percent of the arsenic in the Elkhorn/ Hazard coal was leached by hydrochloric acid, possibly indicating the presence of arsenates that were formed by the oxidation of pyrite. About 25 percent of the arsenic in the Elkhorn/ Hazard coal was leached by nitric acid, suggesting an association with pyrite. Only sixty percent of the total arsenic in the Elkhorn/ Hazard coal was leached. The low percentage of leachable arsenic may be accounted for by unleached pyrite grains, which were detected in solid residues from the nitric acid leach. In the Wyodak coal, arsenic probably occurs in iron oxides or carbonates (35 % arsenic leached by HCl) and clays (15% arsenic leached by HF). Arsenic in the Wyodak coal may also have an organic association, as indicated by low totals for leaching (50% unleached arsenic). In the four program coals 20 to 45 percent of the chromium was leached by hydrofluoric acid, suggesting an association with silicates (probably illite). Microprobe analysis of the Pittsburgh, Elkhorn/ Hazard, and Illinois

  9. 10 CFR 707.9 - Drug testing as a result of an occurrence.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Drug testing as a result of an occurrence. 707.9 Section 707.9 Energy DEPARTMENT OF ENERGY WORKPLACE SUBSTANCE ABUSE PROGRAMS AT DOE SITES Procedures § 707.9 Drug testing as a result of an occurrence. When there is an occurrence which is required to be...

  10. 10 CFR 707.9 - Drug testing as a result of an occurrence.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Drug testing as a result of an occurrence. 707.9 Section 707.9 Energy DEPARTMENT OF ENERGY WORKPLACE SUBSTANCE ABUSE PROGRAMS AT DOE SITES Procedures § 707.9 Drug testing as a result of an occurrence. When there is an occurrence which is required to be...

  11. 10 CFR 707.9 - Drug testing as a result of an occurrence.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Drug testing as a result of an occurrence. 707.9 Section 707.9 Energy DEPARTMENT OF ENERGY WORKPLACE SUBSTANCE ABUSE PROGRAMS AT DOE SITES Procedures § 707.9 Drug testing as a result of an occurrence. When there is an occurrence which is required to be...

  12. 10 CFR 707.9 - Drug testing as a result of an occurrence.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Drug testing as a result of an occurrence. 707.9 Section 707.9 Energy DEPARTMENT OF ENERGY WORKPLACE SUBSTANCE ABUSE PROGRAMS AT DOE SITES Procedures § 707.9 Drug testing as a result of an occurrence. When there is an occurrence which is required to be...

  13. 10 CFR 707.9 - Drug testing as a result of an occurrence.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Drug testing as a result of an occurrence. 707.9 Section 707.9 Energy DEPARTMENT OF ENERGY WORKPLACE SUBSTANCE ABUSE PROGRAMS AT DOE SITES Procedures § 707.9 Drug testing as a result of an occurrence. When there is an occurrence which is required to be...

  14. Metagenome fragment classification based on multiple motif-occurrence profiles.

    PubMed

    Matsushita, Naoki; Seno, Shigeto; Takenaka, Yoichi; Matsuda, Hideo

    2014-01-01

    A vast amount of metagenomic data has been obtained by extracting multiple genomes simultaneously from microbial communities, including genomes from uncultivable microbes. By analyzing these metagenomic data, novel microbes are discovered and new microbial functions are elucidated. The first step in analyzing these data is sequenced-read classification into reference genomes from which each read can be derived. The Naïve Bayes Classifier is a method for this classification. To identify the derivation of the reads, this method calculates a score based on the occurrence of a DNA sequence motif in each reference genome. However, large differences in the sizes of the reference genomes can bias the scoring of the reads. This bias might cause erroneous classification and decrease the classification accuracy. To address this issue, we have updated the Naïve Bayes Classifier method using multiple sets of occurrence profiles for each reference genome by normalizing the genome sizes, dividing each genome sequence into a set of subsequences of similar length and generating profiles for each subsequence. This multiple profile strategy improves the accuracy of the results generated by the Naïve Bayes Classifier method for simulated and Sargasso Sea datasets.

  15. Method for the Prognosis of the Occurrence Date of GLEs

    NASA Astrophysics Data System (ADS)

    Juarez-Zuñiga, A.; Zapotitla-Roman, J.; Alvarez-Madrigal, M.

    2013-05-01

    Ground Level Enhancements are solar relativistic particles measured at earth Ground level by the worldwide network of cosmic ray detectors. These sporadic events are associated to Solar flares and assumed to be of quasi-random nature. Their study gives us information about the source and the propagation processes, about the maximum capacity of the Sun as a particle accelerator engine, the magnetic structure of the traversed medium, etc. Space vehicles may be damaged by this kind of radiation, as well as electric transformers and gas pipes at high latitudes. Their prediction turns to be very important, but because their aleatory occurrence, up to now few efforts have been done, limited to eventual alerts in real time, immediately before their occurrence, but not specific dates are predicted to react well in advance to prevent possible hazards. Here we show that, in spite of their quasi-stochastic nature it is possible to predict the next GLEs, for future solar cycles, and even before 1942 when cosmic ray detectors began to operate. In this work, we reproduce 18 previous events and present results for future events using a confidence intervals statistical analysis to find the values of the mean and standard deviation of the time between events that improve our predictions. Implications point toward a possible synchronization in the solar atmosphere, narrowing their random nature. We foresee our method to be adapted for prediction of other natural phenomena, particularly categoty-5 hurricanes.

  16. Occurrence and persistence of future atmospheric stagnation events.

    PubMed

    Horton, Daniel E; Skinner, Christopher B; Singh, Deepti; Diffenbaugh, Noah S

    2014-08-01

    Poor air quality causes an estimated 2.6 to 4.4 million premature deaths per year(1-3). Hazardous conditions form when meteorological components allow the accumulation of pollutants in the near-surface atmosphere(4-8). Global warming-driven changes to atmospheric circulation and the hydrological cycle(9-13) are expected to alter the meteorological components that control pollutant build-up and dispersal(5-8,14), but the magnitude, direction, geographic footprint, and public health impact of this alteration remain unclear(7,8). We utilize an air stagnation index and an ensemble of bias-corrected climate model simulations to quantify the response of stagnation occurrence and persistence to global warming. Our analysis projects increases in stagnation occurrence that cover 55% of the current global population, with areas of increase affecting 10 times more people than areas of decrease. By the late-21(st) century, robust increases of up to 40 days per year are projected throughout the majority of the tropics and subtropics, as well as within isolated mid-latitude regions. Potential impacts over India, Mexico, and the western U.S. are particularly acute due to the intersection of large populations and increases in the persistence of stagnation events, including those of extreme duration. These results indicate that anthropogenic climate change is likely to alter the level of pollutant management required to meet future air quality targets.

  17. The occurrence and distribution of erionite at Yucca Mountain, Nevada

    SciTech Connect

    Chipera, S.J.; Bish, D.L.

    1989-09-01

    We have conducted an investigation to determine the occurrence and distribution of erionite, a potential carcinogen, at Yucca Mountain, Nevada. Using x-ray powder diffraction techniques yielding detection limits to below 0.05 wt %, we positively identified erionite in only 3 out of 76 bulk and 12 fracture samples investigated. The three erionite-bearing samples (J12-620/630, UE-25aNo.1-1296.2, and USW G4-1314) all occur above the static water level in clay/zeolite-rich horizons near the top of vitrophyres. Erionite occurs as trace amounts of less than 1 wt % in the whole rock, although it may occur locally in significant amounts as fracture fillings (e.g., UE-25aNo.1-1296.2 where it comprises approximately 45 wt % of the fracture filling material). All three occurrences appear to be extremely isolated cases since erionite was not detected in neighboring samples. Erionite at Yucca Mountain apparently formed only in localized microenvironments, possibly restricted to fractures. Since erionite occurs in trace amounts only in extremely isolated instances, it should pose little or no health hazard to workers in the potential repository at Yucca Mountain or to the public. The amounts of erionite liberated to the biosphere should be negligible, particularly when compared with the amounts of erionite occurring naturally at the surface in Nevada and surrounding states. 24 refs., 7 figs., 2 tabs.

  18. [Occurrance of antibodies against Leptospira in horses in Middle Germany].

    PubMed

    Pikalo, Jutta; Sattler, Tatjana; Eichinger, Michaela; Loitsch, Angelika; Sun, Hao; Schmoll, Friedrich; Schusser, Gerald Fritz

    2016-01-01

    Aim of the study was to detect antibodies and potential risk factors for an infec- tion with Leptospira in horses in Middle Germany. Serum samples of 314 horses were examined retrospectively by microscopic agglutination test for the presence of antibodies against eight Leptospira serovars. In total, 17.2% (n = 54) of the horses were positive for one or more of the serovars analyzed. The most prevalent serovar was lcterohaemorrhagiae (11.1%), followed by serovar Bratislava (9.6 %) and Grippotyphosa (1.9%). Mares showed a significantly higher occurrence of antibodies (p < 0.05) than geldings or stallions. Horses used for breeding have a significantly lower risk than horses used in sport or horses used for leisure activity. There was also a significantly higher prevalence (p < 0.05) in summer than in the other seasons. No significant influence of breed, husbandry conditions and age on the antibody occurrence was observed (p > 0.05). The clinical chemical parameters did not differ significantly between horses with positive or negative Leptospira antibody result (p > 0.05). It became apparent that horses can be infected with Leptospira without developing of clinical symptoms. PMID:27344912

  19. Metagenome fragment classification based on multiple motif-occurrence profiles.

    PubMed

    Matsushita, Naoki; Seno, Shigeto; Takenaka, Yoichi; Matsuda, Hideo

    2014-01-01

    A vast amount of metagenomic data has been obtained by extracting multiple genomes simultaneously from microbial communities, including genomes from uncultivable microbes. By analyzing these metagenomic data, novel microbes are discovered and new microbial functions are elucidated. The first step in analyzing these data is sequenced-read classification into reference genomes from which each read can be derived. The Naïve Bayes Classifier is a method for this classification. To identify the derivation of the reads, this method calculates a score based on the occurrence of a DNA sequence motif in each reference genome. However, large differences in the sizes of the reference genomes can bias the scoring of the reads. This bias might cause erroneous classification and decrease the classification accuracy. To address this issue, we have updated the Naïve Bayes Classifier method using multiple sets of occurrence profiles for each reference genome by normalizing the genome sizes, dividing each genome sequence into a set of subsequences of similar length and generating profiles for each subsequence. This multiple profile strategy improves the accuracy of the results generated by the Naïve Bayes Classifier method for simulated and Sargasso Sea datasets. PMID:25210663

  20. Co-occurrence of carbohydrate malabsorption and primary epiploic appendagitis.

    PubMed

    Schnedl, Wolfgang J; Kalmar, Peter; Mangge, Harald; Krause, Robert; Wallner-Liebmann, Sandra J

    2015-09-21

    Unspecific abdominal complaints including bloating and irregular bowel movements may be caused by carbohydrate malabsorption syndromes, e.g., lactose and fructose malabsorption. These symptoms were investigated with hydrogen (H2) breath tests and correlated to carbohydrate malabsorption. During performing these H2-breath tests the patient presented with an acute, localized, non-migratory pain in the left lower abdominal quadrant. Primary epiploic appendagitis is a rare cause of abdominal acute or subacute complaints and diagnosis of primary epiploic appendagitis (PEA) is made when computed tomography reveals a characteristic lesion. We report on a patient with co-occurrence of lactose and fructose malabsorption, which was treated successfully with a diet free of culprit carbohydrates, with PEA recovering without medication or surgical treatment within few days. Since the abdominal unspecific symptoms had been present for months, they appeared not to be correlated to the acute localized abdominal pain, therefore we speculate on a random co-occurrence of combined carbohydrate malabsorption and PEA.

  1. Spatial relationship between landslide occurrence and land cover

    NASA Astrophysics Data System (ADS)

    Lu, P.

    2013-12-01

    Landslide represents a major type of natural hazards. It may leave great threat to human lives as well as infrastructures. In this study, we tried to understand the spatial relationship between landslide occurrences and land cover types through spatial statistics. The approach was based on the bivariate K-functions which can be used to analyze whether there is spatial clustering, repelling or randomness for landslide occurring in areas within different land covers. The Arno River basin in central Italy was chosen as the study area because the landslide inventory is complete with acquired records of more than 27,000 events. According to the inventory, we divided landslides into four classifications according to their types: slides, sofluctions, falls and flows. The land cover data was derived from the CORINE Land Cover map. The land cover types of artificial lands, natural and forest areas, and agriculture lands were focused on. The results indicate that landslides tend to occur in a clustering way within both three land covers. The difference is from the clustering level and spatial dependence distance. Therefore, no evidence can be found that the spatial pattern of landslide occurrence is dependent on changes of land covers.

  2. Occurrence of phosphatidyl-D-serine in the rat cerebrum.

    PubMed

    Omori, Taketo; Mihara, Hisaaki; Kurihara, Tatsuo; Esaki, Nobuyoshi

    2009-05-01

    Phosphatidylserine (PS), a relatively abundant component of mammalian cell membranes, plays important roles in biological processes including apoptosis and cell signaling. It is believed that phosphatidyl-L-serine is the only naturally occurring PS. Here, we describe for the first time the occurrence of phosphatidyl-D-serine (D-PS) in rat cerebrum. Quantitative HPLC analysis of the derivatives of serine liberated from PS by hydrolysis revealed that the amount of D-PS was approximately 1% of the total PS in the cerebrum. Enzymatic cleavage of cerebrum PS with phospholipase D and phospholipase C resulted in the release of both isomers of serine and phosphoserine, respectively, providing additional evidence for the existence of D-PS. Free D-serine was incorporated into PS in an in vitro system using a cerebrum extract, and this activity was inhibited by EDTA, suggesting the occurrence of a divalent cation-dependent enzyme that synthesizes D-PS by a base-exchange reaction.

  3. Occupational effect on the occurrence of idiopathic venous thromboembolism.

    PubMed

    Freeman, Randall J; Jankosky, Christopher; Olsen, Cara H; Mallon, Timothy

    2012-10-01

    Few studies have explored the effects of various occupations on venous thromboembolism occurrence. We examined idiopathic venous thromboembolism (IVTE) occurrence by occupation, body size, and age in the U.S. military. To capture idiopathic cases, exclusion criteria included recognized venous thromboembolism risk factors. Each case was matched to three controls on branch of service, sex, rank/grade, race, and education level. Body mass index, age, and occupation were analyzed with chi2 and logistic regression. Of 2,167 cases, most were male (87%), white (69%), enlisted (78%), averaging 36 years old. IVTE odds increased with age (p < 0.001). Every occupation showed greater odds than pilots/aircrew (p < 0.001), especially infantry/artillery/combat arms, which showed twice the odds, followed by health care workers. Normal weight was protective, especially in pilots/aircrew (OR 0.52, p = 0.03) and repair/engineering (OR 0.72, p < 0.001). Our analysis found a lower risk of IVTE among pilots and aircrew compared to other military occupations. Body size had less impact than expected in aircraft and vehicle operators. Greater odds in health care workers and infantry/artillery/combat arms than in pilots/aircrew and armor/motor transport occupational groups may reflect prolonged standing. Limitations include potential miscoding of health records and potential misclassification. Future IVTE research should explore job functions and worker characteristics.

  4. Circadian occurrence of variceal bleeding in patients with liver cirrhosis.

    PubMed

    Siringo, S; Bolondi, L; Sofia, S; Hermida, R C; Gramantieri, L; Gaiani, S; Piscaglia, F; Carbone, C; Misitano, B; Corinaldesi, R

    1996-12-01

    Several clinical events have a rhythmicity over the 24 h period. We assessed the presence of periodic rhythm in the occurrence of haematemesis in patients with liver cirrhosis under different daylight regimens, namely during standard time and during daylight savings. Over a 48 month period there were 212 consecutive admissions of 118 cirrhotics with variceal bleeding. Complete data were available for 181 episodes of bleeding: 121 (66.9%) started with haematemesis and 60 (33.1%) started with melaena. One hundred and two (56%) episodes occurred during daylight savings and 79 (44%) occurred during standard time. The cosinor test showed a 24 h biphasic peak for the occurrence of haematemesis (09.45 and 21.45 h). Moreover, a biphasic diurnal asymmetric frequency was also found by multiple component rhythmometry. The time peaks of onset of variceal haemorrhage did not change significantly during standard time and daylight savings. Patients with more than one haematemesis episode significantly bled over the same time interval. The present study confirms that over the 24 h period variceal bleeding in cirrhotic patients occurs with a predictable rhythmicity that does not seem to be under the control of the light-dark cycle. The finding of a chronorisk for variceal haemorrhage addresses specific questions for pathophysiological studies as well as for new treatment strategies.

  5. Natural occurrence of mycotoxins in medicinal plants: a review.

    PubMed

    Ashiq, Samina; Hussain, Mubbashir; Ahmad, Bashir

    2014-05-01

    Medicinal plants are widely used as home remedies and raw materials for the pharmaceutical industries. Herbal remedies are used in the prevention, treatment and cure of disorders and diseases since ancient times. However, use of medicinal herbs may not meet the requirements of quality, safety and efficacy. During harvesting, handling, storage and distribution, medicinal plants are subjected to contamination by various fungi, which may be responsible for spoilage and production of mycotoxins. The increasing consumption of medicinal plants has made their use a public health problem due to the lack of effective surveillance of the use, efficacy, toxicity and quality of these natural products. The increase in use of medicinal plants may lead to an increase in the intake of mycotoxins therefore contamination of medicinal plants with mycotoxins can contribute to adverse human health problems and therefore represents a special hazard. Numerous natural occurrences of mycotoxins in medicinal plants and traditional herbal medicines have been reported from various countries including Spain, China, Germany, India, Turkey and from Middle East as well. This review discusses the important mycotoxins and their natural occurrences in medicinal plants and their products.

  6. Occurrences of Chert in Jurassic-Cretaceous Calciturbidites (SW Turkey)

    NASA Astrophysics Data System (ADS)

    Gül, Murat

    2015-10-01

    The Lycian Nappes, containing ophiolite and sedimentary rocks sequences, crop out in the southwest Turkey. The Tavas Nappe is a part of the Lycian Nappes. It includes the Lower Jurassic-Upper Cretaceous calciturbidites. Chert occurrences were observed in the lower part of this calciturbidite. These cherts can be classified on the basis of length, internal structure and host rock. Chert bands are 3.20-35.0min length and 7.0-35.0 cm thick. Chert lenses are 5.0-175.0 cm in length and 1.0-33.0 cm thick. According to its internal structure, granular chert (bladedlarge equitant quartz minerals replaced the big calcite mineral of fossil shell) and porcelanious chert (microcrystalline silica replaced micrite) have been separated. Cherts are generally associated with calcarenite-calcirudite, the others with calcilutite. Micritic calcite patches of cherts point out an uncompleted silicification. The source of silica was dominantly quartz-rich, older, basal rocks and to a lesser extent radiolarians. The coarse-grained calciturbidites act as a way for silica transportation. Some calcite veins (formed during transportation and emplacement of nappes) cut both calciturbidites and cherts. Thus, chert occurrences evolved before emplacement of nappes (the latest Cretaceous-Late Miocene period) during the epigenetic phase.

  7. Occurrence of riverine wetlands on floodplains along a climatic gradient

    USGS Publications Warehouse

    Kroes, D.E.; Brinson, M.M.

    2004-01-01

    The relation between the occurrence of riverine wetlands in floodplains along a humid to semi-arid climatic continuum was studied in two regions. The first included 36 mid-reach streams from Colorado to Iowa, USA, a region with a broad range of PET ratios (potential evapotranspiration/precipitation) from 0.70 to 1.75. The second region included 16 headwater streams in eastern North Carolina with PET ratios ranging from 0.67 to 0.83. Wetland boundaries were identified in the field along transects perpendicular to the floodplain. The width of jurisdictional wetlands was compared with flood-prone width (FPW) and expressed as a percent. An increase in PET ratio corresponded to an exponential decrease in the percentage of the FPW that is wetland. Soil texture, duration of overbank flow, and stream order did not correlate with percentage of FPW that was wetland. Streams with a PET ratio greater than 0.98 did not have wetlands associated with them. Greater channel cross-sectional areas correlated positively with greater wetland widths in both study regions. Overbank flow did not appear to contribute to wetland prevalence. Supplemental ground-water sources, however, as indicated by greater base flows, could not be ruled out as sources contributing to wetland occurrence. ?? 2004, The Society of Wetland Scientists.

  8. Occurrence patterns of lichens on stumps in young managed forests.

    PubMed

    Svensson, Måns; Dahlberg, Anders; Ranius, Thomas; Thor, Göran

    2013-01-01

    The increasing demand for forest-derived bio-fuel may decrease the amount of dead wood and hence also the amount of available substrate for saproxylic ( = dead-wood dependent) organisms. Cut stumps constitute a large portion of dead wood in managed boreal forests. The lichen flora of such stumps has received little interest. Therefore, we investigated which lichens that occur on stumps in young (4-19 years), managed forests and analyzed how species richness and occurrence of individual species were related to stump and stand characteristics. We performed lichen inventories of 576 Norway spruce stumps in 48 forest stands in two study areas in Central Sweden, recording in total 77 lichen species. Of these, 14 were obligately lignicolous, while the remaining were generalists that also grow on bark, soil or rocks. We tested the effect of characteristics reflecting successional stage, microclimate, substrate patch size, and the species pool in the surrounding area on (1) total lichen species richness, (2) species richness of obligately lignicolous lichens and (3) the occurrence of four obligately lignicolous lichen species. The most important variables were stump age, with more species on old stumps, and study area, with similar total species richness but differences in occupancy for individual species. Responses for total lichen species richness and species richness of obligately lignicolous lichens were overall similar, indicating similar ecological requirements of these two groups. Our results indicate that species richness measurements serve as poor proxies for the responses of individual, obligately lignicolous lichen species.

  9. Environmental occurrence of arsenic in Colombia: a review.

    PubMed

    Alonso, David L; Latorre, Sergio; Castillo, Elianna; Brandão, Pedro F B

    2014-03-01

    The international literature on the presence of arsenic (As) in Latin America does not disclose the true magnitude of the presence of As in Colombia. In this paper, we summarize the literature on As occurrence in Colombia. The data reveal that As is present in matrices such as soil, sediments and water and in the food chain. Some of the As concentrations exceed the limits specified by national and international regulations. Arsenic higher concentrations are associated with mining regions (e.g., soils, up to 148 mg/kg; sediments, up to 1400 mg/kg) and agricultural areas (e.g., vegetables, up to 5.40 mg/kg; irrigation water, up to 255 μg/L), and underscore the potential human and environmental risks associated with the presence of As in the country. This review highlights the importance of focusing research on understanding the occurrence, origin and distribution of As in Colombia to better understand its environmental and public health impact.

  10. [Occurrance of antibodies against Leptospira in horses in Middle Germany].

    PubMed

    Pikalo, Jutta; Sattler, Tatjana; Eichinger, Michaela; Loitsch, Angelika; Sun, Hao; Schmoll, Friedrich; Schusser, Gerald Fritz

    2016-01-01

    Aim of the study was to detect antibodies and potential risk factors for an infec- tion with Leptospira in horses in Middle Germany. Serum samples of 314 horses were examined retrospectively by microscopic agglutination test for the presence of antibodies against eight Leptospira serovars. In total, 17.2% (n = 54) of the horses were positive for one or more of the serovars analyzed. The most prevalent serovar was lcterohaemorrhagiae (11.1%), followed by serovar Bratislava (9.6 %) and Grippotyphosa (1.9%). Mares showed a significantly higher occurrence of antibodies (p < 0.05) than geldings or stallions. Horses used for breeding have a significantly lower risk than horses used in sport or horses used for leisure activity. There was also a significantly higher prevalence (p < 0.05) in summer than in the other seasons. No significant influence of breed, husbandry conditions and age on the antibody occurrence was observed (p > 0.05). The clinical chemical parameters did not differ significantly between horses with positive or negative Leptospira antibody result (p > 0.05). It became apparent that horses can be infected with Leptospira without developing of clinical symptoms.

  11. Natural occurrence of mycotoxins in medicinal plants: a review.

    PubMed

    Ashiq, Samina; Hussain, Mubbashir; Ahmad, Bashir

    2014-05-01

    Medicinal plants are widely used as home remedies and raw materials for the pharmaceutical industries. Herbal remedies are used in the prevention, treatment and cure of disorders and diseases since ancient times. However, use of medicinal herbs may not meet the requirements of quality, safety and efficacy. During harvesting, handling, storage and distribution, medicinal plants are subjected to contamination by various fungi, which may be responsible for spoilage and production of mycotoxins. The increasing consumption of medicinal plants has made their use a public health problem due to the lack of effective surveillance of the use, efficacy, toxicity and quality of these natural products. The increase in use of medicinal plants may lead to an increase in the intake of mycotoxins therefore contamination of medicinal plants with mycotoxins can contribute to adverse human health problems and therefore represents a special hazard. Numerous natural occurrences of mycotoxins in medicinal plants and traditional herbal medicines have been reported from various countries including Spain, China, Germany, India, Turkey and from Middle East as well. This review discusses the important mycotoxins and their natural occurrences in medicinal plants and their products. PMID:24594211

  12. Fingerprint liveness detection using multiscale difference co-occurrence matrix

    NASA Astrophysics Data System (ADS)

    Yuan, Chengsheng; Xia, Zhihua; Sun, Xingming; Sun, Decai; Lv, Rui

    2016-06-01

    Fingerprint identification systems have been widely applied in both civilian and governmental applications due to its satisfying performance. However, the fingerprint identification systems can be easily cheated by the presentation of artificial fingerprints made from common materials. Therefore, it reduces the reliability and misleads the decision of the fingerprint identification systems. In this work, we propose a software-based fingerprint liveness detection method based on multiscale difference co-occurrence matrix (DCM). In doing so, multiscale wavelet transform operation is first conducted on the original image. After the preprocessing of the decomposition of the original image, DCMs are computed by using the Laplacian operator. Horizontal and vertical difference co-occurrence matrices are constructed in our method. In order to reduce the dimensionality of the feature vectors, truncation operation is introduced for DCMs. Then, the elements of processing DCMs are regarded as the texture features of original fingerprint images. Finally, classification accuracy of feature vectors is predicted based on a support vector machine classifier. The experimental results have shown that the performance of our method is very promising and meanwhile achieve better accurate classification compared with the best algorithms of LivDet2013 and LivDet2011, while being able to recognize spoofed fingerprints with better recognition accuracy.

  13. Occurrence and evolutionary inferences about Kranz anatomy in Cyperaceae (Poales).

    PubMed

    Martins, Shirley; Alves, Marccus; Scatena, Vera L

    2015-01-01

    Cyperaceae is an angiosperm family with the greatest diversity of species with Kranz anatomy. Four different types of Kranz anatomy (chlorocyperoid, eleocharoid, fimbristyloid and rhynchosporoid) have been described for this angiosperm family, and the occurrence and structural characteristics of these types are important to trace evolutionary hypotheses. The purpose of this study was to examine the available data on Cyperaceae Kranz anatomy, emphasizing taxonomy, geographic distribution, habitat and anatomy, to infer the potential origin of the Kranz anatomy in this family. The results showed that the four types of Kranz anatomy (associated with C4 photosynthesis) in Cyperaceae emerged numerous times in unrelated phylogenetic groups. However, the convergence of these anatomical types, except rhynchosporoid, was observed in certain groups. Thus, the diverse origin of these species might result from different environmental pressures that promote photorespiration. Greater variation in occurrence of Kranz anatomy and anatomical types was observed in Eleocharis, whose emergence of the C4 pathway was recent compared with other genera in the family, and the species of this genus are located in aquatic environments. PMID:26628020

  14. Occurrence of dental consonant misarticulations in different cleft types.

    PubMed

    Laitinen, J; Haapanen, M L; Paaso, M; Pulkkinen, J; Heliövaara, A; Ranta, R

    1998-01-01

    To study the occurrence and type of misarticulations in dental consonants /r/, /s/ and /l/ 280 (115 girls, 165 boys) 6-year-old cleft children were examined by 1 of the 2 experienced speech pathologists of the cleft team. The patients included 82 children with isolated cleft palate (CP), 82 with cleft lip with (34) or without (48) cleft alveolus [CL(A)], 85 with unilateral cleft lip and palate (UCLP) and 31 with bilateral cleft lip and palate (BCLP). CP children were first divided into subgroups; there were 17 children with soft palate cleft, 49 with partial and 16 with complete hard palate cleft. All patients were native Finnish speakers, and had normal hearing, no known syndrome or associated anomalies possibly affecting speech or psychomotor retardation. The results showed that the occurrence and severity as well as the number of errors of all studied sounds separately or grouped increased with the severity of the cleft being constantly greatest in the BCLP group and lowest in the CL(A) group. Altogether 44% of the patients misarticulated at least one studied sound; 41% distorted and 5% substituted, and 2% both distorted and substituted. The /r/ sound was misarticulated by 36%, the /s/ sound by 23%, and the /l/ sound by 18% of the patients. Boys tend to have more problems in producing the studied sounds correctly.

  15. Occurrence and persistence of future atmospheric stagnation events

    PubMed Central

    Horton, Daniel E.; Skinner, Christopher B.; Singh, Deepti; Diffenbaugh, Noah S.

    2014-01-01

    Poor air quality causes an estimated 2.6 to 4.4 million premature deaths per year1–3. Hazardous conditions form when meteorological components allow the accumulation of pollutants in the near-surface atmosphere4–8. Global warming-driven changes to atmospheric circulation and the hydrological cycle9–13 are expected to alter the meteorological components that control pollutant build-up and dispersal5–8,14, but the magnitude, direction, geographic footprint, and public health impact of this alteration remain unclear7,8. We utilize an air stagnation index and an ensemble of bias-corrected climate model simulations to quantify the response of stagnation occurrence and persistence to global warming. Our analysis projects increases in stagnation occurrence that cover 55% of the current global population, with areas of increase affecting 10 times more people than areas of decrease. By the late-21st century, robust increases of up to 40 days per year are projected throughout the majority of the tropics and subtropics, as well as within isolated mid-latitude regions. Potential impacts over India, Mexico, and the western U.S. are particularly acute due to the intersection of large populations and increases in the persistence of stagnation events, including those of extreme duration. These results indicate that anthropogenic climate change is likely to alter the level of pollutant management required to meet future air quality targets. PMID:25309627

  16. Occurrence and persistence of future atmospheric stagnation events

    NASA Astrophysics Data System (ADS)

    Horton, Daniel E.; Skinner, Christopher B.; Singh, Deepti; Diffenbaugh, Noah S.

    2014-08-01

    Poor air quality causes an estimated 2.6-4.4 million premature deaths per year. Hazardous conditions form when meteorological components allow the accumulation of pollutants in the near-surface atmosphere. Global-warming-driven changes to atmospheric circulation and the hydrological cycle are expected to alter the meteorological components that control pollutant build-up and dispersal, but the magnitude, direction, geographic footprint and public health impact of this alteration remain unclear. We used an air stagnation index and an ensemble of bias-corrected climate model simulations to quantify the response of stagnation occurrence and persistence to global warming. Our analysis projects increases in stagnation occurrence that cover 55% of the current global population, with areas of increase affecting ten times more people than areas of decrease. By the late twenty-first century, robust increases of up to 40 days per year are projected throughout the majority of the tropics and subtropics, as well as within isolated mid-latitude regions. Potential impacts over India, Mexico and the western US are particularly acute owing to the intersection of large populations and increases in the persistence of stagnation events, including those of extreme duration. These results indicate that anthropogenic climate change is likely to alter the level of pollutant management required to meet future air quality targets.

  17. Fire occurrence and tussock size modulate facilitation by Ampelodesmos mauritanicus

    NASA Astrophysics Data System (ADS)

    Incerti, Guido; Giordano, Daniele; Stinca, Adriano; Senatore, Mauro; Termolino, Pasquale; Mazzoleni, Stefano; Bonanomi, Giuliano

    2013-05-01

    Facilitation has been reported for a wide range of plant communities, with evidence of interactions between protégé and nurse plants shifting during their ontogenetic cycles. This study showed that large Ampelodesmos mauritanicus tussocks can act as nurse for different species, but only after fire occurrence. Large tussocks are typically composed by an external belt of living tillers surrounding dead standing tillers in the inner area, thus being arranged as a “ring” shape. A low plant diversity in unburned sites, dominated by intact Ampelodesmos tussocks, was related to the intense aboveground competition due to space physical limitation by standing tillers, as well as to the reduction of light availability at ground level. In contrast, after burning, tussocks resprouted only in their external belts, leaving empty inner areas. During post-fire recovery, several species (e.g. Plantago spp., Trifolium spp., Carlina spp.) recolonize the bare soil among different tussocks. On the other hand, a moss (Funaria hygrometrica) and several herbaceous and woody plants (e.g. Spartium junceum, Calicotome villosa, Quercus pubescens subsp. pubescens) were selectively distributed within the ash-full central areas of burned Ampelodesmos tussocks. In summary, the study reported evidence of changing prevalence in the interplay of competition and facilitation effects between small and large Ampelodesmos tussocks, respectively. These results suggest a broad significance of the interactions between fire occurrence and ontogenetic phases of the dominant species in affecting the restoration dynamics of natural plant communities.

  18. Occurrence, behavior and effects of nanoparticles in the environment.

    PubMed

    Nowack, Bernd; Bucheli, Thomas D

    2007-11-01

    The increasing use of engineered nanoparticles (NP) in industrial and household applications will very likely lead to the release of such materials into the environment. Assessing the risks of these NP in the environment requires an understanding of their mobility, reactivity, ecotoxicity and persistency. This review presents an overview of the classes of NP relevant to the environment and summarizes their formation, emission, occurrence and fate in the environment. The engineered NP are thereby compared to natural products such as soot and organic colloids. To date only few quantitative analytical techniques for measuring NP in natural systems are available, which results in a serious lack of information about their occurrence in the environment. Results from ecotoxicological studies show that certain NP have effects on organisms under environmental conditions, though mostly at elevated concentrations. The next step towards an assessment of the risks of NP in the environment should therefore be to estimate the exposure to the different NP. It is also important to notice that most NP in technical applications are functionalized and therefore studies using pristine NP may not be relevant for assessing the behavior of the NP actually used. PMID:17658673

  19. Variation of SEP event occurrence with heliospheric magnetic field magnitudes

    NASA Astrophysics Data System (ADS)

    Kahler, S. W.

    2009-05-01

    Recent work based on nitrate abundances in polar ice cores has shown that large fluence solar energetic (E>30MeV) particle (LSEP) events during the spacecraft era of observations (1960-present) are diminished in comparison with those of some preceding eras detected in the ice cores dating back to 1561. McCracken et al. [McCracken, K.G., Dreschhoff, G.A.M., Smart, D.F., Shea, M.A. A study of the frequency of occurrence of large-fluence solar proton events and the strength of the interplanetary magnetic field, Sol. Phys., 224, 359-372, 2004] have reported an inverse correlation between LSEP events and the magnitudes of the associated reconstructed heliospheric magnetic fields (HMF). A physical working model by McCracken [McCracken, K.G. Changes in the cosmic ray and heliomagnetic components of space climate, 1428-2005, including the variable occurrence of solar energetic particle events, Adv. Space Res., 40, 1070-1077, 2007a; McCracken, K.G. High frequency of occurrence of large solar energetic particle events prior to 1958 and a possible repetition in the near future, Space Weather, 5, S07004, 2007b] is that the lower HMF and coronal magnetic field B imply that fast coronal mass ejections (CMEs) produce shocks with enhanced Alfvenic Mach numbers MA and higher compression ratios r, leading to shock production of more numerous and energetic LSEP events. From a possible decline of the HMF over the next several solar cycles he has urged a watch for a return to the environment of high-frequency, high-fluence LSEP events preceding the current spacecraft era. His LSEP event watch involves three independent questions about (1) the physical model, (2) the prediction of decreasing solar-cycle sunspot numbers and heliomagnetic fields, and (3) the inferred anti-correlation between LSEP events and HMFs. Here we discuss observational evidence bearing on the last question and find little support for the claimed LSEP-HMF anticorrelation.

  20. The probability of occurrence of high-loss windstorms

    NASA Astrophysics Data System (ADS)

    Massey, Neil

    2016-04-01

    Windstorms are one of the largest meteorological risks to life and property in Europe. High - loss windstorms, in terms of insured losses, are a result of not only the windspeed of the storm but also the position and track of the storm. The two highest loss storms on record, Daria (1990) and Lothar (1999) caused so much damage because they tracked across highly populated areas of Europe. Although the frequency and intensity of high - loss wind storms in the observed record is known, there are not enough samples, due to the short observed record, to truly know the distribution of the frequency and intensity of windstorms over Europe and, by extension, the distribution of losses which could occur if the atmosphere had been in a different state due to the internal variability of the atmosphere. Risk and loss modelling exercises carried out by and for the reinsurance industry have typically stochastically perturbed the historical record of high - loss windstorms to produce distributions of potential windstorms with greater sample sizes than the observations. This poster presents a new method of generating many samples of potential windstorms and analyses the frequency of occurrence, intensity and potential losses of these windstorms. The large ensemble regional climate modelling project weather@home is used to generate many regional climate model representations (800 per year) of the weather over Europe between 1985 and 2010. The regional climate model is driven at the boundaries by a free running global climate model and so each ensemble member represents a potential state of the atmosphere, rather than an observed state. The winter storm season of October to March is analysed by applying an objective cyclone identification and tracking algorithm to each ensemble member. From the resulting tracks, the windspeed within a 1000km radius of the cyclone centre is extracted and the maximum windspeed over a 72 hour period is derived as the storm windspeed footprint. This

  1. Future climate data from RCP 4.5 and occurrence of malaria in Korea.

    PubMed

    Kwak, Jaewon; Noh, Huiseong; Kim, Soojun; Singh, Vijay P; Hong, Seung Jin; Kim, Duckgil; Lee, Keonhaeng; Kang, Narae; Kim, Hung Soo

    2014-10-15

    Since its reappearance at the Military Demarcation Line in 1993, malaria has been occurring annually in Korea. Malaria is regarded as a third grade nationally notifiable disease susceptible to climate change. The objective of this study is to quantify the effect of climatic factors on the occurrence of malaria in Korea and construct a malaria occurrence model for predicting the future trend of malaria under the influence of climate change. Using data from 2001-2011, the effect of time lag between malaria occurrence and mean temperature, relative humidity and total precipitation was investigated using spectral analysis. Also, a principal component regression model was constructed, considering multicollinearity. Future climate data, generated from RCP 4.5 climate change scenario and CNCM3 climate model, was applied to the constructed regression model to simulate future malaria occurrence and analyze the trend of occurrence. Results show an increase in the occurrence of malaria and the shortening of annual time of occurrence in the future.

  2. Biochemistry and Occurrence of O-Demethylation in Plant Metabolism

    PubMed Central

    Hagel, Jillian M.; Facchini, Peter J.

    2010-01-01

    Demethylases play a pivitol role in numerous biological processes from covalent histone modification and DNA repair to specialized metabolism in plants and microorganisms. Enzymes that catalyze O- and N-demethylation include 2-oxoglutarate (2OG)/Fe(II)-dependent dioxygenases, cytochromes P450, Rieske-domain proteins and flavin adenine dinucleotide (FAD)-dependent oxidases. Proposed mechanisms for demethylation by 2OG/Fe(II)-dependent enzymes involve hydroxylation at the O- or N-linked methyl group followed by formaldehyde elimination. Members of this enzyme family catalyze a wide variety of reactions in diverse plant metabolic pathways. Recently, we showed that 2OG/Fe(II)-dependent dioxygenases catalyze the unique O-demethylation steps of morphine biosynthesis in opium poppy, which provides a rational basis for the widespread occurrence of demethylases in benzylisoquinoline alkaloid metabolism. PMID:21423357

  3. Mode of occurrence of arsenic in four US coals

    USGS Publications Warehouse

    Kolker, A.; Huggins, Frank E.; Palmer, C.A.; Shah, N.; Crowley, S.S.; Huffman, G.P.; Finkelman, R.B.

    2000-01-01

    An integrated analytical approach has been used to determine the mode of occurrence of arsenic in samples of four widely used US coals: the Pittsburgh, Illinois #6, Elkhorn/Hazard, and Wyodak. Results from selective leaching, X-ray absorption fine structure (XAFS) spectroscopy, and electron microprobe analysis show that pyrite is the principal source of arsenic in the three bituminous coals, but the concentration of As in pyrite varies widely. The Wyodak sample contains very little pyrite; its arsenic appears to be primarily associated with organics, as As3+, or as arsenate. Significant (10-40%) fractions of arsenate, derived from pyrite oxidation, are also present in the three bituminous coal samples. This information is essential in developing predictive models for arsenic behavior during coal combustion and in other environmental settings.

  4. Tsunamis: stochastic models of occurrence and generation mechanisms

    USGS Publications Warehouse

    Geist, Eric L.; David Ogelsby,

    2014-01-01

    The devastating consequences of the 2004 Indian Ocean and 2011 Japan tsunamis have led to increased research into many different aspects of the tsunami phenomenon. In this entry, we review research related to the observed complexity and uncertainty associated with tsunami generation, propagation, and occurrence described and analyzed using a variety of stochastic methods. In each case, seismogenic tsunamis are primarily considered. Stochastic models are developed from the physical theories that govern tsunami evolution combined with empirical models fitted to seismic and tsunami observations, as well as tsunami catalogs. These stochastic methods are key to providing probabilistic forecasts and hazard assessments for tsunamis. The stochastic methods described here are similar to those described for earthquakes (Vere-Jones 2013) and volcanoes (Bebbington 2013) in this encyclopedia.

  5. Chemistry of Glossodoris nudibranchs: specific occurrence of 12-keto scalaranes.

    PubMed

    Manzo, Emiliano; Gavagnin, Margherita; Somerville, Michael J; Mao, Shui-Chun; Ciavatta, M Letizia; Mollo, Ernesto; Schupp, Peter J; Garson, Mary J; Guo, Yue-Wei; Cimino, Guido

    2007-12-01

    With the aim of establishing whether the oxidation of the tricyclic carbon skeleton of scalaradial (1) is specific to Glossodoris mollusks, the chemical investigation of specimens of Glossodoris pallida from two distinct geographical areas (China and Guam) and of Glossodoris vespa and Glossodoris averni from Eastern Australia was performed. 12-Deacetoxy-12-oxo-scalaradial (4), recently reported from another Glossodoris nudibranch, was the main metabolite of G. pallida from China, G. vespa, and G. averni. A series of scalarane compounds 3 and 5-11, including the unprecedented 12,16-deacetoxy-12-oxo-scalarafuran 5, was isolated from the mollusks. Interestingly, a population of G. pallida from Guam displayed a different scalarane pattern that was characterized by scalaradial (1), deacetyl scalaradial (2), and deoxoscalarin (3), thus confirming previous reports. The specific occurrence of 12-keto-derivatives in some nudibranchs of the genus Glossodoris is discussed. PMID:18000710

  6. Reproductive behavior and seasonal occurrence of Psecas viridipurpureus (Salticidae, Araneae).

    PubMed

    Rossa-Feres; Romero; Gonçalves-De- Freitas E; Feres

    2000-05-01

    The reproductive behavior and the seasonal occurrence of Psecas viridipurpureus were studied at the Estação Ecológica do Noroeste Paulista, a small conservation area in the northwest region of São Paulo State, Brazil (49 degrees 22'50"W and 20 degrees 48'36"S). P. viridipurpureus occurred on "gravatá", a bromeliaceous plant (Bromelia balansae, Bromeliaceae) which does not accumulate rain water. During the courtship display the couple occupied the median region of the "gravatá" leaves, with the male always located in a higher position than the female. The males of P. viridipurpureus showed a complex courtship behavior, which included five motor patterns. The courtship and mating behavior occurred preponderantly during the rainy season and the juvenile recruitment between December and July. The retreat of P. viridipurpureus differs from the Salticidae pattern, since the egg sacs are covered with a plain silk cover and are not wrapped in cocoons.

  7. A Bayesian modelling framework for tornado occurrences in North America.

    PubMed

    Cheng, Vincent Y S; Arhonditsis, George B; Sills, David M L; Gough, William A; Auld, Heather

    2015-01-01

    Tornadoes represent one of nature's most hazardous phenomena that have been responsible for significant destruction and devastating fatalities. Here we present a Bayesian modelling approach for elucidating the spatiotemporal patterns of tornado activity in North America. Our analysis shows a significant increase in the Canadian Prairies and the Northern Great Plains during the summer, indicating a clear transition of tornado activity from the United States to Canada. The linkage between monthly-averaged atmospheric variables and likelihood of tornado events is characterized by distinct seasonality; the convective available potential energy is the predominant factor in the summer; vertical wind shear appears to have a strong signature primarily in the winter and secondarily in the summer; and storm relative environmental helicity is most influential in the spring. The present probabilistic mapping can be used to draw inference on the likelihood of tornado occurrence in any location in North America within a selected time period of the year.

  8. [Occurrence of Cryptosporidium spp. infection in antillean manatee (Trichechus manatus)].

    PubMed

    Borges, João Carlos Gomes; Alves, Leucio Câmara; Vergara-Parente, Jociery Einhardt; Faustino, Maria Aparecida da Glória; Machado, Erilane de Castro Lima

    2009-01-01

    Cryptosporidiosis is a zoonosis which can affect man and a wide range of domestic and wild animals, mainly immunodeficient individuals. The objective of this paper was reported the occurrence of a Cryptosporidium infection in Antillean manatee. After an unusual behavior of an Antillean manatee kept in captivity at the Centro Mamíferos Aquáticos, ICMBio--FMA, clinical examination and posterior fecal sampling was performed. Fecal samples were examined by the Kinyoun technique, Direct Immunofluorescence Test and also examined by 4',6'-Diamidino-2-Phenylindole (DAPI) staining. At the clinical examination, the animal showed signs of abdominal pain. The results obtained by light and fluorescence microscopy analysis showed the presence of Cryptosporidium spp. oocyst in feces of this manatee.

  9. Influence of temperature changes on migraine occurrence in Germany.

    PubMed

    Scheidt, Jörg; Koppe, Christina; Rill, Sven; Reinel, Dirk; Wogenstein, Florian; Drescher, Johannes

    2013-07-01

    Many factors trigger migraine attacks. Weather is often reported to be one of the most common migraine triggers. However, there is little scientific evidence about the underlying mechanisms and causes. In our pilot study, we used smartphone apps and a web form to collect around 4,700 migraine messages in Germany between June 2011 and February 2012. Taking interdiurnal temperature changes as an indicator for changes in the prevailing meteorological conditions, our analyses were focused on the relationship between temperature changes and the frequency of occurrence of migraine attacks. Linear trends were fitted to the total number of migraine messages with respect to temperature changes. Statistical and systematic errors were estimated. Both increases and decreases in temperature lead to a significant increase in the number of migraine messages. A temperature increase (decrease) of 5 °C resulted in an increase of 19 ± 7 % (24 ± 8 %) in the number of migraine messages. PMID:22895651

  10. Occurrence of Earth-like bodies in planetary systems.

    PubMed

    Wetherill, G W

    1991-08-01

    Present theories of terrestrial planet formation predict the rapid ;;runaway formation'' of planetary embryos. The sizes of the embryos increase with heliocentric distance. These embryos then merge to form planets. In earlier Monte Carlo simulations of the merger of these embryos it was assumed that embryos did not form in the asteroid belt, but this assumption may not be valid. Simulations in which runaways were allowed to form in the asteroid belt show that, although the initial distributions of mass, energy, and angular momentum are different from those observed today, during the growth of the planets these distributions spontaneously evolve toward those observed, simply as a result of known solar system processes. Even when a large planet analogous to ;;Jupiter'' does not form, an Earth-sized planet is almost always found near Earth's heliocentric distance. These results suggest that occurrence of Earth-like planets may be a common feature of planetary systems.

  11. [Occurrence of Cryptosporidium spp. infection in antillean manatee (Trichechus manatus)].

    PubMed

    Borges, João Carlos Gomes; Alves, Leucio Câmara; Vergara-Parente, Jociery Einhardt; Faustino, Maria Aparecida da Glória; Machado, Erilane de Castro Lima

    2009-01-01

    Cryptosporidiosis is a zoonosis which can affect man and a wide range of domestic and wild animals, mainly immunodeficient individuals. The objective of this paper was reported the occurrence of a Cryptosporidium infection in Antillean manatee. After an unusual behavior of an Antillean manatee kept in captivity at the Centro Mamíferos Aquáticos, ICMBio--FMA, clinical examination and posterior fecal sampling was performed. Fecal samples were examined by the Kinyoun technique, Direct Immunofluorescence Test and also examined by 4',6'-Diamidino-2-Phenylindole (DAPI) staining. At the clinical examination, the animal showed signs of abdominal pain. The results obtained by light and fluorescence microscopy analysis showed the presence of Cryptosporidium spp. oocyst in feces of this manatee. PMID:19500463

  12. Marine algal toxins: origins, health effects, and their increased occurrence.

    PubMed Central

    Van Dolah, F M

    2000-01-01

    Certain marine algae produce potent toxins that impact human health through the consumption of contaminated shellfish and finfish and through water or aerosol exposure. Over the past three decades, the frequency and global distribution of toxic algal incidents appear to have increased, and human intoxications from novel algal sources have occurred. This increase is of particular concern, since it parallels recent evidence of large-scale ecologic disturbances that coincide with trends in global warming. The extent to which human activities have contributed to their increase therefore comes into question. This review summarizes the origins and health effects of marine algal toxins, as well as changes in their current global distribution, and examines possible causes for the recent increase in their occurrence. Images Figure 2 Figure 3 PMID:10698729

  13. An occurrence of autunite, Lawrence County, South Dakota

    USGS Publications Warehouse

    Vickers, Rollin C.

    1953-01-01

    In July 1952 an occurrence of autunite was found in the northern part of the Black Hills, South Dakota, during a reconnaissance for radioactive deposits. The autunite occurs as fracture coatings and disseminations in siltstone of the Deadwood formation of Cambrian age and is concentrated mainly in the lower 2 feet of the siltstone at the contact with an intrusive rhyolite porphyry; the radioactive zone is exposed in two old workings, which are 90 feet apart. An 18-inch vertical channel sample of the autanite-bearing siltstene contained 0. 048 percent uranium. The gangue minerals are fluorite and limonite. The uranium is believed to have been introduced into the siltstone by solutions of magmatic origin that migrated along the lower contact of the siltstone after or during emplacement of the porphyry'

  14. Unusual occurrence of cystic fibrosis and alobar holoprosencephaly.

    PubMed

    Cherian, Mathew P; Al-Sanna'a, Nouriya A

    2008-04-01

    Holoprosencephaly (HPE) is a defect of embryonic forebrain resulting from failure of growth and segmentation of the anterior end of the neural tube. It has been classified into 4 types based on the severity of associated brain and facial malformations. The most severe variety called alobar HPE is generally associated with major cranio-facial anomalies such as cyclopia, ethmocephaly, cebocephaly, or cleft-lip/palate. Significant etiological heterogeneity exists in HPE and includes both genetic and environmental causes. Maternal diabetes is a well-established environmental factor with a significant increased risk for HPE. We report on a Saudi Arab girl born to a diabetic mother, with the alobar type of holoprosencephaly, associated with very minimal cranio-facial defects. However, she displayed several other congenital malformations. In addition, she was diagnosed with cystic fibrosis. Simultaneous occurrence of cystic fibrosis and congenital anomalies has been rare. PMID:21063314

  15. Influence of temperature changes on migraine occurrence in Germany

    NASA Astrophysics Data System (ADS)

    Scheidt, Jörg; Koppe, Christina; Rill, Sven; Reinel, Dirk; Wogenstein, Florian; Drescher, Johannes

    2013-07-01

    Many factors trigger migraine attacks. Weather is often reported to be one of the most common migraine triggers. However, there is little scientific evidence about the underlying mechanisms and causes. In our pilot study, we used smartphone apps and a web form to collect around 4,700 migraine messages in Germany between June 2011 and February 2012. Taking interdiurnal temperature changes as an indicator for changes in the prevailing meteorological conditions, our analyses were focused on the relationship between temperature changes and the frequency of occurrence of migraine attacks. Linear trends were fitted to the total number of migraine messages with respect to temperature changes. Statistical and systematic errors were estimated. Both increases and decreases in temperature lead to a significant increase in the number of migraine messages. A temperature increase (decrease) of 5 °C resulted in an increase of 19 ± 7 % (24 ± 8 %) in the number of migraine messages.

  16. Cerulean Warbler occurrence and habitat use of Oklahoma

    USGS Publications Warehouse

    Leslie,, David M.; O'Connell, Timothy J.; Cavalieri, Vincent S.

    2011-01-01

    Dendroica cerulea (Cerulean Warbler) is a migrant songbird that has declined rangewide in recent decades. We surveyed 150 sites in 2006–2007 to determine if this species still occupied its former breeding range in Oklahoma. We located Cerulean Warblers at 5 sites and confirmed breeding on north slopes of two heavily forested ridges in the Ouachita Mountains. We did not encounter Cerulean Warblers in any bottomland hardwoods, despite the former widespread distribution and abundance of the species in such habitats. While habitat loss and degradation may limit occurrence of Cerulean Warbler in some areas, the pattern of decline for this species at the edge of its range in Oklahoma is also consistent with abandonment of peripheral range as the range-wide population declines.

  17. The occurrence and properties of disks around young stars

    NASA Technical Reports Server (NTRS)

    Beckwith, Steven V. W.; Sargent, Anneila I.

    1993-01-01

    The paper discusses the occurrence and properties of disks around young stars, emphasizing in particular how these may relate to planet formation and the evolution of the solar system. The global properties of such disks often resemble those attributed to the primitive solar nebula, suggesting that conditions appropriate for planet formation commonly accompany the birth of low-mass stars. Disk masses, between 0.001 and 1 solar mass, are generally lower than those of the stars, and may represent only a fraction (less than about 10 percent) of the total system mass. From the paucity of near-IR radiation from some disks it is inferred that the inner regions there are gaps where the opacity from small particles becomes vanishingly small. Evidence is presented to the effect that gaps in the inner disks develop preferentially in the oldest objects, suggesting that, with time, matter is lost or accumulates into large particles such as planetesimals, which cannot yet be detected.

  18. Relationship of pheasant occurrence to barium in Illinois soils.

    PubMed

    Jones, R L

    1992-04-01

    Distribution of the ring-necked pheasant (Phasianus colchicus) is nearly co-extensive with the boundary of Wisconsinan glaciation; this is an area of base-rich soils that are mostly developed in calcareous tills. Anderson and Stewart (1973) speculated that barium in the diet might be a factor limiting the pheasant establishment in habitats adjacent to areas of long-term sustaining populations in Illinois. Total Ba was calculated for soils of 74 conterminous counties for which there were pheasant population data. Barium over the range of about 480 to 700 mg kg(-1) soil was unrelated to pheasant occurrence or to population indeces. The selective eating of iron-manganese concretions that are enriched in Ba might present a unique pathway for Ba loading.

  19. A new occurrence of telluride minerals in South Carolina.

    USGS Publications Warehouse

    Bell, H.; Larson, R.R.

    1984-01-01

    A study of drill cores from the Haile gold mine, Lancaster County, South Carolina, has revealed grains containing large amounts of Te with various combinations of Pb, Ag and Au in pyrite. These telluride minerals have so far not been identified. The nearby Brewer mine, on the basis of chemical evidence, also contains tellurides. The probable telluride localities in South Carolina are now expanded to three, significantly increasing the few reports of Te minerals from the Au deposits of the southeastern Piedmont, many of which are now considered to be volcanogenic. The occurrence of telluride minerals in gold ore from the Haile-Brewer area may help to explain the divergence in Au/Ag ratios reported in chemical analyses of drill core, ore samples and production records. Te, in addition, may be useful in geochemical exploration programmes in the SE Piedmont, including programmes using heavy mineral concentrates derived from stream alluvium. -R.S.M.

  20. Occurrence and estimation of lead and zinc compounds in coal

    SciTech Connect

    Moss, K.N.; Hirst, A.A.; Needham, L.W.

    1980-09-01

    Samples of coal and ash deposits from a boiler were examined by chemical and spectroscopic methods to determine the presence of Pb and Zn in coal. A description of the spectrographic and chemical techniques used is included in the report. Analysis of ash deposits from a boiler indicated the presence of potash and soda in chloride forms as well as trace amounts of Pb and Zn. Specific results of the 3 ash deposits analyzed appear in tabular form in the report. Results of the analysis of the coal samples indicated the presence of small amounts of Pb and Zn with the latter being present in greater amounts (approximately 0.001%). Overall, the presence of both Pb and Zn was established in coal and additional analysis was considered necessary before the distribution and mode of occurrence could be established.

  1. Asbestos occurrence in the Eagle C-4 quadrangle, Alaska

    USGS Publications Warehouse

    Foster, Helen Laura

    1969-01-01

    An asbestos occurrence was discovered in a remote part of the Eagle quadrangle, Alaska, in the summer of 1968 during geologic reconnaissance in connection with the U.S. Geological Survey's Heavy Metals program. The exposed part of the deposit consists of large joint blocks of serpentine which are cut by closely spaced subparallel veins. Most of the veins are about ? inch thick, and they consist of cross-fiber chrysotile asbestos. The asbestos appears to be of commercial quality, but the total quantity is unknown. The asbestos occurs in a serpentinized ultramafic mass which appears to intrude metamorphic rocks. Many other serpentinized ultramafic masses are known in the Eagle quadrangle, but this is the first one in which considerable asbestos has been found. The deposit is of importance because it shows that geologic conditions are locally favorable for the formation of asbestos in the Yukon-Tanana Upland, and hope of finding commercial asbestos deposits thus seems possible.

  2. Marine algal toxins: origins, health effects, and their increased occurrence.

    PubMed

    Van Dolah, F M

    2000-03-01

    Certain marine algae produce potent toxins that impact human health through the consumption of contaminated shellfish and finfish and through water or aerosol exposure. Over the past three decades, the frequency and global distribution of toxic algal incidents appear to have increased, and human intoxications from novel algal sources have occurred. This increase is of particular concern, since it parallels recent evidence of large-scale ecologic disturbances that coincide with trends in global warming. The extent to which human activities have contributed to their increase therefore comes into question. This review summarizes the origins and health effects of marine algal toxins, as well as changes in their current global distribution, and examines possible causes for the recent increase in their occurrence.

  3. [Effect of natural factors on the occurrence of cardiovascular diseases].

    PubMed

    Nuzhdina, M A

    1998-01-01

    The effect of natural environmental factors (indexes of solar activity, geomagnetic disturbances, as well as meteorologic parameters: air temperature and humidity, and atmospheric pressure) on the occurrence of cardiovascular diseases in Ukraine as a whole and in Kiev was analyzed. It is shown that, contrary to the stereotype, the yearly dynamics of cardiovascular diseases in 1980-1990 is in opposite phase with the solar activity cycle. Similar results were obtained for the monthly dynamics of cardiovascular diseases in the period from June 1991 to June 1993. The relative influence of five environmental factors (in complex) on the daily dynamics of cardiovascular diseases for the same period was calculated. The role of heliogeophysical factors becomes especially evident if the daily level of cardiovascular diseases within some month of the year is considered. This result may be interesting for medicinal practice and forecasting of cardiovascular diseases. PMID:9783071

  4. A study of the occurrence of supercooling of water

    NASA Astrophysics Data System (ADS)

    Tan, Kah-Chye; Ho, Wenxian; Katz, J. I.; Feng, Shi-Jiang

    2016-04-01

    Supercooling of water can be easily studied with a simple apparatus suitable for the student laboratory. We describe such an apparatus and its capabilities. The parameters influencing supercooling include the initial water temperature, as well as the type and temperature of the chilling medium. We correlate the occurrence of supercooling with the ability of the chilling medium to promptly nucleate ice; if it nucleates promptly, the layer of ice crystals formed on the boundary will initiate freezing of the bulk water without supercooling. If the chilling medium is unable to nucleate ice promptly, ice nucleation is delayed and the water supercools. Students can study and compare supercooling of distilled and natural water. Even quite dirty river water may be supercooled by as much as 5 °C.

  5. Fire occurrence prediction in the Mediterranean: Application to Southern France

    NASA Astrophysics Data System (ADS)

    Papakosta, Panagiota; Öster, Jan; Scherb, Anke; Straub, Daniel

    2013-04-01

    The areas that extend in the Mediterranean basin have a long fire history. The climatic conditions of wet winters and long hot drying summers support seasonal fire events, mainly ignited by humans. Extended land fragmentation hinders fire spread, but seasonal winds (e.g. Mistral in South France or Meltemia in Greece) can drive fire events to become uncontrollable fires with severe impacts to humans and the environment [1]. Prediction models in these areas should incorporate both natural and anthropogenic factors. Several indices have been developed worldwide to express fire weather conditions. The Canadian Fire Weather Index (FWI) is currently adapted by many countries in Europe due to the easily observable input weather parameters (temperature, wind speed, relative humidity, precipitation) and the easy-to-implement algorithms of the Canadian formulation describing fuel moisture relations [2],[3]. Human influence can be expressed directly by human presence (e.g. population density) or indirectly by proxy indicators (e.g. street density [4], land cover type). The random nature of fire occurrences and the uncertainties associated with the influencing factors motivate probabilistic prediction models. The aim of this study is to develop a prediction model of fire occurrence probability under natural and anthropogenic influence in Southern France and to compare it with earlier developed predictions in other Mediterranean areas [5]. Fire occurrence is modeled as a Poisson process. Two interpolation methods (Kriging and Inverse Distance Weighting) are used to interpolate daily weather observations from weather stations to a 1 km² spatial grid and their results are compared. Poisson regression estimates the parameters of the model and the resulting daily predictions are provided in terms of maps displaying fire occurrence rates. The model is applied to the regions Provence-Alpes-Côtes D'Azur und Languedoc-Roussillon in the South of France. Weather data are obtained from

  6. A remote sensing evaluation of potential for sinkhole occurrence

    NASA Technical Reports Server (NTRS)

    Casper, J.; Ruth, B.; Degner, J. (Principal Investigator)

    1981-01-01

    The relationship between lowering of the water table and sinkhole development in Pierson and in Hillsborough County, Florida was investigated. The locations of recently developed (1973) collapses were examined with respect to lineaments or fracture traces that are expressed in the terrain and visible in aerial photography and satellite imagery. It was anticipated that these relationships would provide the basis for establishment of criteria for mapping those land areas that have the greatest potential for sinkhole development. A very good correlation was found between mapped lineament intersections and known location of sinkhole occurrences for both study areas. This indicates that lineament and fracture trace mapping may be very useful in locating zones with the greatest potential for sinkhole development. It is further shown that this information is quite beneficial in land use planning applications.

  7. Occurrence and dynamics of micropollutants in a karst aquifer.

    PubMed

    Morasch, Barbara

    2013-02-01

    Karst systems represent important yet vulnerable drinking water resources. A wide spectrum of pollutants may be released into karst groundwater from agriculture, livestock farming, private households, and industry. This work provides an overview on the occurrence and dynamics of micropollutants in a karst system of the Swiss Jura. Ten months of intensive monitoring for micropollutants confirmed that the swallow hole draining an agricultural plain was the main entry path for pesticides into the karst system and the two connected springs. Elevated fungicide concentrations in winter and occasional quantification of pharmaceuticals suggested wood- or façade treatment and domestic sewer as additional sources of contamination. A continuous atrazine signal in the low ng/L range might affect the autochthonous endokarst microbial community and represents a potential risk for the human population through karst groundwater.

  8. Tsunamis: stochastic models of occurrence and generation mechanisms

    USGS Publications Warehouse

    Geist, Eric L.; Oglesby, David D.

    2014-01-01

    The devastating consequences of the 2004 Indian Ocean and 2011 Japan tsunamis have led to increased research into many different aspects of the tsunami phenomenon. In this entry, we review research related to the observed complexity and uncertainty associated with tsunami generation, propagation, and occurrence described and analyzed using a variety of stochastic methods. In each case, seismogenic tsunamis are primarily considered. Stochastic models are developed from the physical theories that govern tsunami evolution combined with empirical models fitted to seismic and tsunami observations, as well as tsunami catalogs. These stochastic methods are key to providing probabilistic forecasts and hazard assessments for tsunamis. The stochastic methods described here are similar to those described for earthquakes (Vere-Jones 2013) and volcanoes (Bebbington 2013) in this encyclopedia.

  9. Occurrence and dynamics of micropollutants in a karst aquifer.

    PubMed

    Morasch, Barbara

    2013-02-01

    Karst systems represent important yet vulnerable drinking water resources. A wide spectrum of pollutants may be released into karst groundwater from agriculture, livestock farming, private households, and industry. This work provides an overview on the occurrence and dynamics of micropollutants in a karst system of the Swiss Jura. Ten months of intensive monitoring for micropollutants confirmed that the swallow hole draining an agricultural plain was the main entry path for pesticides into the karst system and the two connected springs. Elevated fungicide concentrations in winter and occasional quantification of pharmaceuticals suggested wood- or façade treatment and domestic sewer as additional sources of contamination. A continuous atrazine signal in the low ng/L range might affect the autochthonous endokarst microbial community and represents a potential risk for the human population through karst groundwater. PMID:23202643

  10. Concurrent Occurrence of Uterovaginal and Rectal Prolapse: An Uncommon Presentation

    PubMed Central

    Umeh, UA; Ugwu, EO; Obi, SN; Nnagbo, JE

    2015-01-01

    Concomitant uterovaginal and rectal prolapse is an uncommon occurrence. Where laparoscopic equipment and skills are lacking, sacrohysteropexy with synthetic mesh and rectopexy can be accomplished by laparotomy, especially in women who desire to retain their uterus for either biological or psychological reasons. A 40-year-old primipara with a history of concomitant mass protruding from both her vagina and anus following a spontaneous unsupervised delivery at home. Following pelvic examination, a diagnosis of uterovaginal and rectal prolapse was made. In view of her parity and desire to retain her reproductive function, she was offered abdominal sacrohysteropexy with synthetic mesh and rectopexy with satisfactory postoperative recovery. In resource-limited settings with concomitant uterine and rectal prolapse, open abdominal sacrohysteropexy with synthetic mesh and rectopexy is an effective and safe alternative to Manchester operation in the absence of laparoscopic equipment and skills. PMID:26500795

  11. Occurrence and methods of control of chemical contaminants in foods.

    PubMed Central

    Jelinek, C

    1981-01-01

    Contamination of food by chemicals can result from their use on agricultural commodities; accidents or misuse during food handling and processing; nucler weapon testing and operation of nuclear power plants; and disposal of industrial chemicals or by-products with subsequent dispersal into the environment. The Food and Drug Administration (FDA), as the Federal agency mainly responsible for evaluating the hazards of chemical contaminants and enforcing any established tolerance levels for them in foods, has been monitoring pesticides, industrial chemicals, metals, and radionuclides in foods in its nationwide programs for many years. In addition, FDA searches for potential contaminants among the approximately 50,000 industrial chemicals manufactured in the United States and coordinates its efforts with those of other Federal and state agencies in these investigations. The overall results of the FDA surveillance and compliance programs for chemical contaminants in foods, as well as specific examples illustrating the wide range of incidents and types of occurrences, are presented. PMID:6786871

  12. Occurrence of Trichinella spp. in wild animals in northwestern Libya.

    PubMed

    Hosni, M M; Maghrbi, A A El; Ganghish, K S

    2013-01-01

    The present study determined the occurrence of Trichinella spp. in captured and some perished wildlife animals which included 70 hedgehogs, 19 red foxes, 13 common jackals and 8 crested porcupines in northwestern Libya. Muscle samples of these animals were examined by trichinoscopy. Trichinella larvae were detected only in 4 (5.7%) of the hedgehogs (Erinaceus algirus) and 2 (10.5%) of the red foxes (Vulpes vulpes). Larvae were found in the muscles of the diaphragm, abdomen, tongue, forelimb, hindlimb and intercostal muscles. Examination of tissue sections revealed the presence of numerous cysts within the muscle fibers containing one or more coiled or elongated larvae. Inflammatory cell infiltration was observed around the cysts especially at their poles. Results indicated the importance of wild animals as reservoirs of Trichinella larvae and their role in the transmission of the disease to other wild and domestic animals as well as humans. PMID:26623318

  13. [Solanine and chaconine: occurrence, properties, methods for determination].

    PubMed

    Badowski, P; Urbanek-Karłowska, B

    1999-01-01

    Glycoalkaloids are naturally occurring toxicants in plants that are members of the Solanaceae family. In this paper occurrence of glycoalkaloids, especially solanine and chaconine in potatoes and tomatoes, were reviewed. Basing on literature, toxicological properties and methods of determination were reported. Attention was paid to common content of glycoalkaloids in potatoes and tomatoes and their commercial products. Solanine and chaconine are usually present at low levels in large majority of current commercial varieties but they can accumulate to high levels in greened, stored, damaged potatoes. High concentration may cause acute poisoning, including gastro-intestinal and neurological disturbances, in man. The upper limit, recognized as a safe (non-toxic), was presented. According to WHO normal levels in potatoes 20-100 mg per kg of potatoes is not of toxicological concern.

  14. Future credible precipitation occurrences in Los Alamos, New Mexico

    SciTech Connect

    Abeele, W.V.

    1980-09-01

    I have studied many factors thought to have influenced past climatic change. Because they might recur, they are possible suspects for future climatic alterations. Most of these factors are totally unpredictable; therefore, they cast a shadow on the validity of derived climatic predictions. Changes in atmospheric conditions and in continental surfaces, variations in solar radiation, and in the earth's orbit around the sun are among the influential mechanisms investigated. Even when models are set up that include the above parameters, their reliability will depend on unpredictable variables totally alien to the model (like volcanic eruptions). Based on climatic records, however, maximum precipitation amounts have been calculated for different probability levels. These seem to correspond well to past precipitation occurrences, derived from tree ring indices. The link between tree ring indices and local climate has been established through regression analysis.

  15. Lunettes: A Global Inventory of Their Occurrence and Characteristics

    NASA Astrophysics Data System (ADS)

    Rhodes, D. D.

    2012-12-01

    Lunettes (including "clay dunes") form along the downwind margins of saline pans. As landforms they were little studied and poorly understood until the mid-20th century when they attracted the attention of Australian geomorphologists, notably James W. Bowler. During the last 40 years, lunettes have been studied extensively as indicators of climate change. Their occurrence has now been documented on every continent except Antarctica. Inspection of more than 100 research sites using Google Earth has led to the recognition that lunettes occur in three definable, though somewhat overlapping, settings. Playas and lunettes are common features of closed basins having sub-humid climates. Large basins with internal drainage due to structural deformation produce the most extensive and complex lake and dune systems (e.g., the Etosha Pan, northern Namibia; Soda Lake, Carrizo Plain, California). In these settings, the large central basin is associated with lunettes that may be more than 10 km long and as much as 50 m high. Tens of lunette ridges may mark former lake levels and channels of the desiccated drainage system. Some basins lack external drainage for hydrological reasons (low precipitation, drainage diversion, etc.). These hydrologically closed basins may also host saline lakes and lunettes (e.g., Lake Malheur, Oregon) though they are generally smaller and less complex. Shallow depressions may occur by the thousands on the surface of arid and semi-arid plains such as Brazil's Pantanal, and the Kalahari and Transvaal of southern Africa, the High Plains of Texas and New Mexico, and several parts of Australia. Although they have not been described in the literature, pans also cover large areas in China, Tibet, and Mongolia. Multiple theories have been advanced to explain the occurrence of plains pans including deflation, piping, subsidence, and animal activity. In the plains setting, pans can occur in large numbers, up to 100 per 100 km2 and may cover 20% or more of the

  16. Uniqueness: skews bit occurrence frequencies in randomly generated fingerprint libraries.

    PubMed

    Chen, Nelson G

    2016-08-01

    Requiring that randomly generated chemical fingerprint libraries have unique fingerprints such that no two fingerprints are identical causes a systematic skew in bit occurrence frequencies, the proportion at which specified bits are set. Observed frequencies (O) at which each bit is set within the resulting libraries systematically differ from frequencies at which bits are set at fingerprint generation (E). Observed frequencies systematically skew toward 0.5, with the effect being more pronounced as library size approaches the compound space, which is the total number of unique possible fingerprints given the number of bit positions each fingerprint contains. The effect is quantified for varying library sizes as a fraction of the overall compound space, and for changes in the specified frequency E. The cause and implications for this systematic skew are subsequently discussed. When generating random libraries of chemical fingerprints, the imposition of a uniqueness requirement should either be avoided or taken into account.

  17. Influenza activity in Thailand and occurrence in different climates.

    PubMed

    Prachayangprecha, Slinporn; Vichaiwattana, Preeyaporn; Korkong, Sumeth; Felber, Joshua A; Poovorawan, Yong

    2015-01-01

    This study observed influenza activity between June 2009 and July 2014 in Thailand, a country in the Northern hemisphere with a tropical climate, and compared the results to activity in the United States (US) and Australia, which represent temperate climates in the Northern and Southern hemispheres, respectively. From Thailand, a total of 17,416 specimens were collected from patients exhibiting influenza-like illnesses and subjected to real-time PCR for the detection of influenza viruses. For comparison, laboratory confirmations of influenza originating from the US and Australia were obtained from the US CDC's FluView surveillance reports and the Australian Government's Department of Health and Ageing websites. We found that, generally, the influenza season in Thailand starts with the rainy season. This observation of influenza's annual incidence pattern provides a better understanding of its occurrence, suggesting that vaccination campaigns should be started before the influenza season begins in order to reduce transmission.

  18. A Bayesian modelling framework for tornado occurrences in North America.

    PubMed

    Cheng, Vincent Y S; Arhonditsis, George B; Sills, David M L; Gough, William A; Auld, Heather

    2015-01-01

    Tornadoes represent one of nature's most hazardous phenomena that have been responsible for significant destruction and devastating fatalities. Here we present a Bayesian modelling approach for elucidating the spatiotemporal patterns of tornado activity in North America. Our analysis shows a significant increase in the Canadian Prairies and the Northern Great Plains during the summer, indicating a clear transition of tornado activity from the United States to Canada. The linkage between monthly-averaged atmospheric variables and likelihood of tornado events is characterized by distinct seasonality; the convective available potential energy is the predominant factor in the summer; vertical wind shear appears to have a strong signature primarily in the winter and secondarily in the summer; and storm relative environmental helicity is most influential in the spring. The present probabilistic mapping can be used to draw inference on the likelihood of tornado occurrence in any location in North America within a selected time period of the year. PMID:25807465

  19. Occurrence of Trichinella spp. in wild animals in northwestern Libya

    PubMed Central

    Hosni, M.M.; Maghrbi, A.A. El; Ganghish, K.S.

    2013-01-01

    The present study determined the occurrence of Trichinella spp. in captured and some perished wildlife animals which included 70 hedgehogs, 19 red foxes, 13 common jackals and 8 crested porcupines in northwestern Libya. Muscle samples of these animals were examined by trichinoscopy. Trichinella larvae were detected only in 4 (5.7%) of the hedgehogs (Erinaceus algirus) and 2 (10.5%) of the red foxes (Vulpes vulpes). Larvae were found in the muscles of the diaphragm, abdomen, tongue, forelimb, hindlimb and intercostal muscles. Examination of tissue sections revealed the presence of numerous cysts within the muscle fibers containing one or more coiled or elongated larvae. Inflammatory cell infiltration was observed around the cysts especially at their poles. Results indicated the importance of wild animals as reservoirs of Trichinella larvae and their role in the transmission of the disease to other wild and domestic animals as well as humans. PMID:26623318

  20. Co-occurrence network analysis of Chinese and English poems

    NASA Astrophysics Data System (ADS)

    Liang, Wei; Wang, Yanli; Shi, Yuming; Chen, Guanrong

    2015-02-01

    A total of 572 co-occurrence networks of Chinese characters and words as well as English words are constructed from both Chinese and English poems. It is found that most of the networks have small-world features; more Chinese networks have scale-free properties and hierarchical structures as compared with the English networks; all the networks are disassortative, and the disassortativeness of the Chinese word networks is more prominent than those of the English networks; the spectral densities of the Chinese word networks and English networks are similar, but they are different from those of the ER, BA, and WS networks. For the above observed phenomena, analysis is provided with interpretation from a linguistic perspective.

  1. Heterocyclic amines: occurrence and prevention in cooked food.

    PubMed Central

    Robbana-Barnat, S; Rabache, M; Rialland, E; Fradin, J

    1996-01-01

    This article deals with the mutagenic heterocyclic amines, especially the aminoimidazoazaarenes family, isolated from cooked foods. The conditions which lead to their occurrence in foods are discussed. This formation primarily depends on the characteristics of the food, such as the type of the food and the presence of precursors, water, and lipids. Secondarily, it depends on the cooking modes where the temperature is considered to be the most important factor involved in their formation. As their formation during cooking represents a health risk, we present some ways and means to limit their formation by alternative cooking methods that tend to decrease heterocyclic amine concentrations in foods as they are implicated in cancer risks. PMID:8919766

  2. Contaminated concrete: Occurrence and emerging technologies for DOE decontamination

    SciTech Connect

    Dickerson, K.S.; Wilson-Nichols, M.J.; Morris, M.I.

    1995-08-01

    The goals of the Facility Deactivation, Decommissioning, and Material Disposition Focus Area, sponsored by the US Department of Energy (DOE) Office of Technology Development, are to select, demonstrate, test, and evaluate an integrated set of technologies tailored to provide a complete solution to specific problems posed by deactivation, decontamination, and decommissioning, (D&D). In response to these goals, technical task plan (TTP) OR152002, entitled Accelerated Testing of Concrete Decontamination Methods, was submitted by Oak Ridge National Laboratory. This report describes the results from the initial project tasks, which focused on the nature and extent of contaminated concrete, emerging candidate technologies, and matching of emerging technologies to concrete problems. Existing information was used to describe the nature and extent of contamination (technology logic diagrams, data bases, and the open literature). To supplement this information, personnel at various DOE sites were interviewed, providing a broad perspective of concrete contamination. Because characterization is in the initial stage at many sites, complete information is not available. Assimilation of available information into one location is helpful in identifying potential areas of concern in the future. The most frequently occurring radiological contaminants within the DOE complex are {sup 137}Cs, {sup 238}U (and it daughters), and {sup 60}Co, followed closely by {sup 90}Sr and tritium, which account for {minus}30% of the total occurrence. Twenty-four percent of the contaminants were listed as unknown, indicating a lack of characterization information, and 24% were listed as other contaminants (over 100 isotopes) with less than 1% occurrence per isotope.

  3. Established time series measure occurrence and frequency of episodic events.

    NASA Astrophysics Data System (ADS)

    Pebody, Corinne; Lampitt, Richard

    2015-04-01

    Established time series measure occurrence and frequency of episodic events. Episodic flux events occur in open oceans. Time series making measurements over significant time scales are one of the few methods that can capture these events and compare their impact with 'normal' flux. Seemingly rare events may be significant on local scales, but without the ability to measure the extent of flux on spatial and temporal scales and combine with the frequency of occurrence, it is difficult to constrain their impact. The Porcupine Abyssal Plain Sustained Observatory (PAP-SO) in the Northeast Atlantic (49 °N 16 °W, 5000m water depth) has measured particle flux since 1989 and zooplankton swimmers since 2000. Sediment traps at 3000m and 100 metres above bottom, collect material year round and we have identified close links between zooplankton and particle flux. Some of these larger animals, for example Diacria trispinosa, make a significant contribution to carbon flux through episodic flux events. D. trispinosa is a euthecosome mollusc which occurs in the Northeast Atlantic, though the PAP-SO is towards the northern limit of its distribution. Pteropods are comprised of aragonite shell, containing soft body parts excepting the muscular foot which extends beyond the mouth of the living animal. Pteropods, both live-on-entry animals and the empty shells are found year round in the 3000m trap. Generally the abundance varies with particle flux, but within that general pattern there are episodic events where significant numbers of these animals containing both organic and inorganic carbon are captured at depth and therefore could be defined as contributing to export flux. Whether the pulse of animals is as a result of the life cycle of D. trispinosa or the effects of the physics of the water column is unclear, but the complexity of the PAP-SO enables us not only to collect these animals but to examine them in parallel to the biogeochemical and physical elements measured by the

  4. Paleohydrologic techniques used to define the spatial occurrence of floods

    USGS Publications Warehouse

    Jarrett, R.D.

    1990-01-01

    Defining the cause and spatial characteristics of floods may be difficult because of limited streamflow and precipitation data. New paleohydrologic techniques that incorporate information from geomorphic, sedimentologic, and botanic studies provide important supplemental information to define homogeneous hydrologic regions. These techniques also help to define the spatial structure of rainstorms and floods and improve regional flood-frequency estimates. The occurrence and the non-occurrence of paleohydrologic evidence of floods, such as flood bars, alluvial fans, and tree scars, provide valuable hydrologic information. The paleohydrologic research to define the spatial characteristics of floods improves the understanding of flood hydrometeorology. This research was used to define the areal extent and contributing drainage area of flash floods in Colorado. Also, paleohydrologic evidence was used to define the spatial boundaries for the Colorado foothills region in terms of the meteorologic cause of flooding and elevation. In general, above 2300 m, peak flows are caused by snowmelt. Below 2300 m, peak flows primarily are caused by rainfall. The foothills region has an upper elevation limit of about 2300 m and a lower elevation limit of about 1500 m. Regional flood-frequency estimates that incorporate the paleohydrologic information indicate that the Big Thompson River flash flood of 1976 had a recurrence interval of approximately 10,000 years. This contrasts markedly with 100 to 300 years determined by using conventional hydrologic analyses. Flood-discharge estimates based on rainfall-runoff methods in the foothills of Colorado result in larger values than those estimated with regional flood-frequency relations, which are based on long-term streamflow data. Preliminary hydrologic and paleohydrologic research indicates that intense rainfall does not occur at higher elevations in other Rocky Mountain states and that the highest elevations for rainfall-producing floods

  5. Occurrence of bacteria and biochemical markers on public surfaces.

    PubMed

    Reynolds, Kelly A; Watt, Pamela M; Boone, Stephanie A; Gerba, Charles P

    2005-06-01

    From 1999-2003, the hygiene of 1061 environmental surfaces from shopping, daycare, and office environments, personal items, and miscellaneous activities (i.e., gymnasiums, airports, movie theaters, restaurants, etc.), in four US cities, was monitored. Samples were analyzed for fecal and total coliform bacteria, protein, and biochemical markers. Biochemical markers, i.e., hemoglobin (blood marker), amylase (mucus, saliva, sweat, and urine marker), and urea (urine and sweat marker) were detected on 3% (26/801); 15% (120/801), and 6% (48/801) of the surfaces, respectively. Protein (general hygiene marker) levels > or = 200 microg/10 cm2 were present on 26% (200/801) of the surfaces tested. Surfaces from children's playground equipment and daycare centers were the most frequently contaminated (biochemical markers on 36%; 15/42 and 46%; 25/54, respectively). Surfaces from the shopping, miscellaneous activities, and office environments were positive for biochemical markers with a frequency of 21% (69/333), 21% (66/308), and 11% (12/105), respectively). Sixty samples were analyzed for biochemical markers and bacteria. Total and fecal coliforms were detected on 20% (12/60) and 7% (4/ 60) of the surfaces, respectively. Half and one-third of the sites positive for biochemical markers were also positive for total and fecal coliforms, respectively. Artificial contamination of public surfaces with an invisible fluorescent tracer showed that contamination from outside surfaces was transferred to 86% (30/ 35) of exposed individual's hands and 82% (29/35) tracked the tracer to their home or personal belongings hours later. Results provide information on the relative hygiene of commonly encountered public surfaces and aid in the identification of priority environments where contaminant occurrence and risk of exposure may be greatest. Children's playground equipment is identified as a priority surface for additional research on the occurrence of and potential exposure to infectious

  6. Widespread occurrence of ranavirus in pond-breeding amphibian populations.

    PubMed

    Hoverman, Jason T; Gray, Matthew J; Miller, Debra L; Haislip, Nathan A

    2012-03-01

    Ranaviruses are an emerging threat for many amphibian populations, yet their distribution in amphibian communities and the association of infection with possible stressors and species is not fully understood due to historically sparse surveillance. Agricultural practices that reduce the water quality of amphibian breeding habitats (e.g., cattle access to wetlands) and environmental stressors (e.g., lower temperatures) may contribute to ranavirus emergence. We tested larval amphibians for ranavirus infection across four seasons in farm ponds (n = 40) located in Tennessee, USA. Cattle at various densities were allowed access to half of the sampled ponds. Ranavirus infections were detected in nine species and in 33 of the sampled ponds (83%), illustrating widespread occurrence of the pathogen. Species within the family Ranidae were the most frequently infected. In 13 of the ponds containing infected individuals, prevalence exceeded 40% during at least one season. Infections were detected in multiple seasons in 20 of the sampled ponds containing infections, suggesting that ranaviruses are relatively persistent in these systems. Cattle had negative effects on water quality (turbidity and ammonia) and there was a positive association between cattle abundance and ranavirus prevalence in the summer. Counter to previous field studies in North America, we found a significant positive association between water temperature and ranavirus prevalence in the fall sampling events. Despite these findings, the influences of cattle and temperature on ranavirus prevalence were not consistent across seasons. As such, the mechanisms driving high ranavirus prevalence across the landscape and over time remain unclear. Given the widespread occurrence of ranaviruses in wild amphibians, we encourage the implementation of surveillance programs to help identify potential drivers of emergence. Sites with high ranavirus prevalence should be monitored annually for outbreaks, and the long

  7. Dynamics of whale shark occurrence at their fringe oceanic habitat.

    PubMed

    Afonso, Pedro; McGinty, Niall; Machete, Miguel

    2014-01-01

    Studies have shown that the whale shark (Rhincodon typus), a vulnerable large filter feeder, seasonally aggregates at highly productive coastal sites and that individuals can perform large, trans-boundary migrations to reach these locations. Yet, the whereabouts of the whale shark when absent from these sites and the potential oceanographic and biological drivers involved in shaping their present and future habitat use, including that located at the fringes of their suitable oceanic habitat, are largely unknown. We analysed a 16-year (1998-2013) observer dataset from the pole-and-line tuna fishery across the Azores (mid-North Atlantic) and used GAM models to investigate the spatial and temporal patterns of whale shark occurrence in relation to oceanographic features. Across this period, the whale shark became a regular summer visitor to the archipelago after a sharp increase in sighting frequency seen in 2008. We found that SST helps predicting their occurrence in the region associated to the position of the seasonal 22°C isotherm, showing that the Azores are at a thermal boundary for this species and providing an explanation for the post 2007 increase. Within the region, whale shark detections were also higher in areas of increased bathymetric slope and closer to the seamounts, coinciding with higher chl-a biomass, a behaviour most probably associated to increased feeding opportunities. They also showed a tendency to be clustered around the southernmost island of Santa Maria. This study shows that the region integrates the oceanic habitat of adult whale shark and suggests that an increase in its relative importance for the Atlantic population might be expected in face of climate change. PMID:25028929

  8. Automatically identification of Equatorial Spread-F occurrence on ionograms

    NASA Astrophysics Data System (ADS)

    Pillat, Valdir Gil; Fagundes, Paulo Roberto; Guimarães, Lamartine Nogueira Frutuoso

    2015-12-01

    F-region large-scale irregularities, also called plasma bubbles, are one of the most interesting equatorial ionospheric phenomena. These irregularities are generated in the equatorial region and afterwards extend to lower latitudes. They are one of the important topics of investigation in equatorial ionosphere electrodynamics and, therefore, are subject to intense theoretical and experimental research. The ionosonde is the most used scientific equipment to study the ionosphere and the F-region. With advancement of digital ionosonde, it is now possible to carry out an ionospheric sounding with a cadence of 5 min or even with 1-minute cadence. To analyse a large amount of ionograms, more sophisticated tools are needed. Thus, development of algorithms to identify and analyse different aspects of ionograms has become very important to space science researchers. Multiple echoes recorded on ionograms are the signature of these irregularities in the ionograms, usually called Spread-F. Spread-F is classified into three types: range, frequency, and mixed. Thus, automatic identification of Spread-F is important in ionospheric studies, because studies usually involve the analysis and interpretation of large numbers of ionograms. The main objective of this paper is to present a new computational tool, based on fuzzy relation, designed to automatically identify the occurrence of Spread-F in ionograms. The test was conducted in ionograms recorded in the Brazilian sector (São José dos Campos (23.2°S, 45.9°W, dip latitude 17.6°S-low latitude) and Palmas (10.2°S, 48.2°W, dip latitude 5.5°S-near the magnetic equatorial)). The automatic identification of Spread-F occurrence was compared with those obtained manually and good agreement was found.

  9. Automatically identification of Equatorial Spread-F occurrence on ionograms

    NASA Astrophysics Data System (ADS)

    Fagundes, P. R.; Pillat, V. G.; Guimarães, L. N. F.

    2015-12-01

    F-region large-scale irregularities, also called plasma bubbles, are one of the most interesting equatorial ionospheric phenomena. These irregularities are generated in the equatorial region and afterwards extend to lower latitudes. They are one of the important topics of investigation in equatorial ionosphere electrodynamics and, therefore, are subject to intense theoretical and experimental research. The ionosonde is the most used scientific equipment to study the ionosphere and the F-region. With advancement of digital ionosonde, it is now possible to carry out an ionospheric sounding with a cadence of 5 minutes or even with 1-minute cadence. To analyse a large amount of ionograms, more sophisticated tools are needed. Thus, development of algorithms to identify and analyse different aspects of ionograms has become very important to space science researchers. Multiple echoes recorded on ionograms are the signature of these irregularities in the ionograms, usually called Spread-F. Spread-F is classified into three types: range, frequency, and mixed. Thus, automatic identification of Spread-F is important in ionospheric studies, because studies usually involve the analysis and interpretation of large numbers of ionograms. The main objective of this paper is to present a new computational tool, based on fuzzy relation, designed to automatically identify the occurrence of Spread-F in ionograms. The test was conducted in ionograms recorded in the Brazilian sector (São José dos Campos (23.2° S, 45.9° W, dip latitude 17.6° S - low latitude) and Palmas (10.2° S, 48.2° W, dip latitude 5.5° S - near the magnetic equatorial)). The automatic identification of Spread-F occurrence was compared with those obtained manually and good agreement was found.

  10. 27-day solar cycle signature in NLC occurrence rates

    NASA Astrophysics Data System (ADS)

    Robert, Charles; von Savigny, Christian; Burrows, John P.; Deland, Matthew

    Noctilucent clouds (NLC) are optically thin layered phenomena which are usually observed at an altitude of about 83 km during the summer season at latitudes polewards of 55° . They are made of water ice particles, the size of which is estimated to be generally smaller than 100 nm. They exist as the consequence of the cold and humid upper mesosphere at high latitudes during the summer season, and are believed to be extremely sensitive to both temperature and water vapor content. As a consequence, they are often perceived as possible early indicators of global change. Satellite measurements provide global measurements of NLC and contribute significantly to our understanding of their behavior. Although the main features of the seasonal change of NLC occurrence rates are now established, variations of NLC activity on shorter timescale are not so well understood. It was shown that dynamical processes such as planetary waves, gravity waves and atmospheric tides can affect NLC, mainly through temperature alteration. Other processes can influence NLC, such as solar-proton event and possibly lunar cycle. It was also shown that on longer timescales, NLC are affected by the 11-year solar cycle. Using SCIAMACHY and SBUV/2 satellite measurements, we present here evidence that the occurrence rates of NLC exhibit a 27-day cycle. This variation seems to be correlated with the solar lyman-alpha flux, especially during years of stronger solar activity. MLS mesospheric water vapor and temperature available during some of the NLC season will be presented alongside in order to better understand the connection between the different processes. Possible physical mechanisms are discussed.

  11. Dynamics of whale shark occurrence at their fringe oceanic habitat.

    PubMed

    Afonso, Pedro; McGinty, Niall; Machete, Miguel

    2014-01-01

    Studies have shown that the whale shark (Rhincodon typus), a vulnerable large filter feeder, seasonally aggregates at highly productive coastal sites and that individuals can perform large, trans-boundary migrations to reach these locations. Yet, the whereabouts of the whale shark when absent from these sites and the potential oceanographic and biological drivers involved in shaping their present and future habitat use, including that located at the fringes of their suitable oceanic habitat, are largely unknown. We analysed a 16-year (1998-2013) observer dataset from the pole-and-line tuna fishery across the Azores (mid-North Atlantic) and used GAM models to investigate the spatial and temporal patterns of whale shark occurrence in relation to oceanographic features. Across this period, the whale shark became a regular summer visitor to the archipelago after a sharp increase in sighting frequency seen in 2008. We found that SST helps predicting their occurrence in the region associated to the position of the seasonal 22°C isotherm, showing that the Azores are at a thermal boundary for this species and providing an explanation for the post 2007 increase. Within the region, whale shark detections were also higher in areas of increased bathymetric slope and closer to the seamounts, coinciding with higher chl-a biomass, a behaviour most probably associated to increased feeding opportunities. They also showed a tendency to be clustered around the southernmost island of Santa Maria. This study shows that the region integrates the oceanic habitat of adult whale shark and suggests that an increase in its relative importance for the Atlantic population might be expected in face of climate change.

  12. Relationships between rainfall and Combined Sewer Overflow (CSO) occurrences

    NASA Astrophysics Data System (ADS)

    Mailhot, A.; Talbot, G.; Lavallée, B.

    2015-04-01

    Combined Sewer Overflow (CSO) has been recognized as a major environmental issue in many countries. In Canada, the proposed reinforcement of the CSO frequency regulations will result in new constraints on municipal development. Municipalities will have to demonstrate that new developments do not increase CSO frequency above a reference level based on historical CSO records. Governmental agencies will also have to define a framework to assess the impact of new developments on CSO frequency and the efficiency of the various proposed measures to maintain CSO frequency at its historic level. In such a context, it is important to correctly assess the average number of days with CSO and to define relationships between CSO frequency and rainfall characteristics. This paper investigates such relationships using available CSO and rainfall datasets for Quebec. CSO records for 4285 overflow structures (OS) were analyzed. A simple model based on rainfall thresholds was developed to forecast the occurrence of CSO on a given day based on daily rainfall values. The estimated probability of days with CSO have been used to estimate the rainfall threshold value at each OS by imposing that the probability of exceeding this rainfall value for a given day be equal to the estimated probability of days with CSO. The forecast skill of this model was assessed for 3437 OS using contingency tables. The statistical significance of the forecast skill could be assessed for 64.2% of these OS. The threshold model has demonstrated significant forecast skill for 91.3% of these OS confirming that for most OS a simple threshold model can be used to assess the occurrence of CSO.

  13. Dynamics of Whale Shark Occurrence at Their Fringe Oceanic Habitat

    PubMed Central

    Afonso, Pedro; McGinty, Niall; Machete, Miguel

    2014-01-01

    Studies have shown that the whale shark (Rhincodon typus), a vulnerable large filter feeder, seasonally aggregates at highly productive coastal sites and that individuals can perform large, trans-boundary migrations to reach these locations. Yet, the whereabouts of the whale shark when absent from these sites and the potential oceanographic and biological drivers involved in shaping their present and future habitat use, including that located at the fringes of their suitable oceanic habitat, are largely unknown. We analysed a 16-year (1998–2013) observer dataset from the pole-and-line tuna fishery across the Azores (mid-North Atlantic) and used GAM models to investigate the spatial and temporal patterns of whale shark occurrence in relation to oceanographic features. Across this period, the whale shark became a regular summer visitor to the archipelago after a sharp increase in sighting frequency seen in 2008. We found that SST helps predicting their occurrence in the region associated to the position of the seasonal 22°C isotherm, showing that the Azores are at a thermal boundary for this species and providing an explanation for the post 2007 increase. Within the region, whale shark detections were also higher in areas of increased bathymetric slope and closer to the seamounts, coinciding with higher chl-a biomass, a behaviour most probably associated to increased feeding opportunities. They also showed a tendency to be clustered around the southernmost island of Santa Maria. This study shows that the region integrates the oceanic habitat of adult whale shark and suggests that an increase in its relative importance for the Atlantic population might be expected in face of climate change. PMID:25028929

  14. Overview of the occurrence of natural gas hydrate

    SciTech Connect

    Kvenvolden, K.A.

    1995-12-31

    Large amounts of methane, the principal component of natural gas, occur in the form of solid gas hydrate in sediment and sedimentary rock within {approximately}2,000 m of the Earth`s surface in polar and deep-water regions. The stability of gas hydrate in nature is controlled by an interrelation among factors of temperature, pressure, and gas-water composition that restricts the occurrence of gas hydrate to continental and continental-shelf sediment of high-latitude regions, where surface temperatures are slightly higher to less than {approximately}0{degrees}C, and to oceanic (aquatic) sediment worldwide, where bottom-water temperatures approach 0{degrees}C and water depths exceed {approximately}300 m. Naturally occurring gas hydrate was first recognized in the 1960`s in polar continental settings in Russia, particularly at the Messoyakha field of western Siberia. Samples of continental gas hydrate were first tested in 1972 from the west end of the Prudhoe Bay oil field in Alaska. Since the 1970`s, gas-hydrate samples have been cored and observed at about 14 subaquatic locations, providing irrefutable evidence that gas hydrate occurs as a natural substance in a variety of geologic settings. Most of these subaquatic samples have come from sediment in active (convergent) margins, but passive (divergent) margins are also appropriate settings for gas-hydrate occurrence. Three aspects of natural gas hydrate are of particular interest. Because gas hydrate contains large amounts of resource. Because gas hydrate is metastable, it can dissociate, triggering sediment instability, and thus become a geologic hazard. Because gas hydrate both stores and releases methane, a greenhouse gas, it may be a factor in global climate change.

  15. Occurrence of Anaerobic Ammonium Oxidation in the Yangtze Estuary

    NASA Astrophysics Data System (ADS)

    Hou, L.

    2013-12-01

    Over the past several decades, a large quantity of reactive nitrogen has been transported into the Yangtze estuarine and coastal water, due to intense human activities in the Yangtze River Basin. At present, it annually receives a high load of anthropogenic inorganic nitrogen (about 1.1 × 1011 mol N) from increased agricultural activities, fish farming, and domestic and industrial wastewater discharge in the Yangtze River Basin, consequently leading to severe eutrophication and frequent occurrences of harmful algal blooms in the estuary and adjacent coastal areas. Hence, the microbial nitrogen transformations are of major concern in the Yangtze Estuary. Anaerobic ammonium oxidation (anammox) has been reported to play a significant role in the removal of reactive nitrogen in aquatic ecosystems. In this study, the occurrences of anammox bacteria and associated activity in the Yangtze Estuary were evidenced with molecular and isotope-tracing techniques. It is observed that the anammox bacteria at the study area mainly consisted of Candidatus Scalindua, Brocadia, Kuenenia. Salinity was found to be a key environmental factor controlling distribution and diversity of the anammox bacterial community at the estuarine ecosystem. Also, temperature and organic carbon had significant influences on anammox bacterial biodiversity. Q-PCR assays of anammox bacteria indicated that their abundance had a range of 2.63 ×106 - 9.48 ×107 copies g-1 dry sediment, with high spatiotemporal heterogeneity. The potential anammox activities measured in the present work varied between 0.94 - 6.61nmol N g-1 dry sediment h-1, which were related to temperature, nitrite and anammox bacterial abundance. On the basis of the 15N tracing experiments, the anammox process was estimated to contribute 6.6 - 12.9 % to the total nitrogen loss whereas the remainder was attributed to denitrification.

  16. High Arctic wetlands: Their occurrence, hydrological characteristics and sustainability

    NASA Astrophysics Data System (ADS)

    Woo, Ming-ko; Young, Kathy L.

    2006-04-01

    High Arctic wetlands, though limited in occurrence, are an important ecological niche, providing the major vegetated areas in an arid and cold polar desert environment. These wetlands are often found as patches in the barren landscape. At a few locales which may be ice-wedge polygonal grounds, glacial terrain and zones of recent coastal uplift, wetland occurrence can become extensive, forming a mosaic that comprises patches of different wetland types. Reliable water supply during the thawed season is a deciding factor in wetland sustainability. The sources include meltwater from late-lying snowbanks, localized ground water discharge, streamflow, inundation by lakes and the sea, and for some ice-wedge wetlands, ground-ice melt. Different types of wetlands have their own characteristics, and peat accumulation or diatom depositions are common. The peat cover insulates the wetland from summer heating and encourages permafrost aggradation, with the feedback that a shallow frost table reduces the moisture storage capacity in a thinly thawed layer, which becomes easily saturated. All the wetlands studied have high calcium content since they are formed on carbonate terrain. Coastal wetlands have high salt concentration while snowmelt and ground-ice melt provides dilution. The sustainability of High Arctic wetlands is predicated upon water supply exceeding the losses to evaporation and lateral drainage. Disturbances due to natural causes such as climatic variations, geomorphic changes, or human-induced drainage, can reduce inundation opportunities or increase outflow. Then, the water table drops, the vegetation changes and the peat degrades, leading to the detriment of the wetlands.

  17. Etiology and occurrence of gingival recession - An epidemiological study

    PubMed Central

    Mythri, Sarpangala; Arunkumar, Suryanarayan Maiya; Hegde, Shashikanth; Rajesh, Shanker Kashyap; Munaz, Mohamed; Ashwin, Devasya

    2015-01-01

    Objectives: Gingival recession is the term used to characterize the apical shift of the marginal gingiva from its normal position on the crown of the tooth. It is frequently observed in adult subjects. The occurrence and severity of the gingival recession present considerable differences between populations. To prevent gingival recession from occurring, it is essential to detect the underlying etiology. The aim of the present study was to determine the occurrence of gingival recession and to identify the most common factor associated with the cause of gingival recession. Methods: A total of 710 subjects aged between 15 years to 60 years were selected. Data were collected by an interview with the help of a proforma and then the dental examination was carried out. The presence of gingival recession was recorded using Miller's classification of gingival recession. The Silness and Loe Plaque Index, Loe and Silness gingival index, community periodontal index were recorded. The data thus obtained were subjected to statistical analysis using Chi-square test and Student's unpaired t-test. Results: Of 710 subjects examined, 291 (40.98%) subjects exhibited gingival recession. The frequency of gingival recession was found to increase with age. High frequency of gingival recession was seen in males (60.5%) compared to females (39.5%). Gingival recession was commonly seen in mandibular incisors (43.0%). Miller's class I gingival recession was more commonly seen. The most common cause for gingival recession was dental plaque accumulation (44.1%) followed by faulty toothbrushing (42.7%). Conclusion: Approximately half of the subjects examined exhibited gingival recession. The etiology of gingival recession is multifactorial, and its appearance is always the result of more than one factor acting together. PMID:26941519

  18. Rainfall thresholds for shallow landslides occurrence in Calabria, southern Italy

    NASA Astrophysics Data System (ADS)

    Vennari, C.; Gariano, S. L.; Antronico, L.; Brunetti, M. T.; Iovine, G.; Peruccacci, S.; Terranova, O.; Guzzetti, F.

    2013-09-01

    In many areas, rainfall is the primary trigger of landslides. Determining the rainfall conditions responsible for landslide occurrence is important, and may contribute to save lives and properties. In a long-term national project for the definition of rainfall thresholds for possible landslide occurrence in Italy, and for the implementation of a national landslide warning system, we compiled a catalogue of 186 rainfall events that have resulted in 251 shallow landslides in Calabria, southern Italy, from January 1996 to September 2011. Landslides were located geographically using Google Earth®, and were given a mapping and a temporal accuracy. We used the landslide information, and sub-hourly rainfall measurements obtained from two complementary networks of rain gauges, to determine cumulated event vs. rainfall duration (ED) thresholds for Calabria. For the purpose, we adopted an existing method used to prepare rainfall thresholds and to estimate their associated uncertainties in central Italy. The regional thresholds for Calabria were found nearly identical to previous ED thresholds for Calabria obtained using a reduced set of landslide information, and slightly higher than the ED thresholds obtained for central Italy. We segmented the regional catalogue of rainfall events with landslides on lithology, soil regions, rainfall zones, and seasonal periods. The number of events in each subdivision was insufficient to determine reliable thresholds, but allowed for preliminary conclusions on the role of the environmental factors on the rainfall conditions responsible for shallow landslides in Calabria. We further segmented the regional catalogue based on administrative subdivisions used for hydro-meteorological monitoring and operational flood forecasting, and we determined separate ED thresholds for the Tyrrhenian and the Ionian coasts of Calabria. We expect the ED rainfall thresholds for Calabria to be used in regional and national landslide warning systems. The

  19. Rainfall thresholds for shallow landslide occurrence in Calabria, southern Italy

    NASA Astrophysics Data System (ADS)

    Vennari, C.; Gariano, S. L.; Antronico, L.; Brunetti, M. T.; Iovine, G.; Peruccacci, S.; Terranova, O.; Guzzetti, F.

    2014-02-01

    In many areas, rainfall is the primary trigger of landslides. Determining the rainfall conditions responsible for landslide occurrence is important, and may contribute to saving lives and properties. In a long-term national project for the definition of rainfall thresholds for possible landslide occurrence in Italy, we compiled a catalogue of 186 rainfall events that resulted in 251 shallow landslides in Calabria, southern Italy, from January 1996 to September 2011. Landslides were located geographically using Google Earth®, and were given a mapping and a temporal accuracy. We used the landslide information, and sub-hourly rainfall measurements obtained from two complementary networks of rain gauges, to determine cumulated event vs. rainfall duration (ED) thresholds for Calabria. For this purpose, we adopted an existing method used to prepare rainfall thresholds and to estimate their associated uncertainties in central Italy. The regional thresholds for Calabria were found to be nearly identical to previous ED thresholds for Calabria obtained using a reduced set of landslide information, and slightly higher than the ED thresholds obtained for central Italy. We segmented the regional catalogue of rainfall events with landslides in Calabria into lithology, soil regions, rainfall zones, and seasonal periods. The number of events in each subdivision was insufficient to determine reliable thresholds, but allowed for preliminary conclusions about the role of the environmental factors in the rainfall conditions responsible for shallow landslides in Calabria. We further segmented the regional catalogue based on administrative subdivisions used for hydro-meteorological monitoring and operational flood forecasting, and we determined separate ED thresholds for the Tyrrhenian and the Ionian coasts of Calabria. We expect the ED rainfall thresholds for Calabria to be used in regional and national landslide warning systems. The thresholds can also be used for landslide hazard

  20. Past Occurrences of Hypoxia in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Zillen, L.; Conley, D. J.; Bjorck, S.

    2007-12-01

    The hypoxic zone in the Baltic Sea has increased in area by about four times since 1950. Widespread oxygen deficiency below the halocline has severely reduced macro benthic communities in the Baltic Proper and the Gulf of Finland over the past decades and negatively effected food chain dynamics, fish habitats and fisheries in the entire Baltic Sea. In addition, hypoxia alters nutrient biogeochemical cycles. The cause of the increased hypoxia is believed to be enhanced eutrophication through increased anthropogenic input of nutrients, such as phosphorous and nitrogen. Conditions prior to the 1950s are considered as the benchmark and some authors suggest that the earlier Baltic Sea was an oligothrophic, clear-water body with oxygenated deep waters. By contrast, studies of short sediment cores reveal that hypoxia has been present in some of the deepest basins for at least the last 100-200 years. In addition, long sediment cores suggest that hypoxia in the Baltic Sea has occurred intermittently in deep basins over the last c. 8500 years. Thus, the occurrence of present day hypoxia in the deeper basins need not necessarily be attributed to human activity but rather to natural oceanographic, geologic and climate conditions. We present a compilation of previous publications that reported the occurrence of laminated sediments (i.e. a palaeo-proxy for hypoxia) in the Baltic Sea. This review shows that the deeper parts of the Baltic Sea have experienced either intermittent or more regular hypoxia during most of the Holocene and that more continuous laminations started to form c. 7800-8500 cal. yr BP ago, in association with the establishment of a permanent halocline during the transition from the Ancylus Lake to the Littorina Sea. Laminated sediments were more common during the early and late Holocene and coincided with intervals of high organic productivity (high TOC content) and high salinity during the Holocene Thermal Maximum and the Medieval Climate Optimum. This study

  1. Climate variability and wildfire risk and occurrence in northern Spain

    NASA Astrophysics Data System (ADS)

    Garcia Codron, J. C.; Rasilla, D.; Diego, C.; Carracedo, V.

    2009-04-01

    In spite of their reputation of wetness, wildfires are a frequent event in Cantabria (Northern Spain), but their seasonality does not match the typical warm season maximum generalized in most of the Iberian Peninsula. They occur at the end of the winter and the beginning of the spring (January to March), being mostly anthropogenically triggered due to the necessity of preparing pastures in the uplands. However, catastrophic episodes of generalized burning are controlled by different atmospheric mechanisms, namely the occurrence of "Suradas", a downslope windstorms which combines high winds speeds and low humidities, and long periods of drought in late fall and winter. This contribution analyzes long term trends (1961 onwards) of several climatic variables during the highest wildfire risk period in order to assess to what extent the occurrence of wildfires may be linked to the recent climatic variability. Raw meteorological values of temperature, humidity, wind speed and precipitation are transformed into a well-known meteorological fire weather index, the Canadian Forest Fire Index (FWI). Besides, monthly values of the Palmer Drought Severity Index we used to assess the spatial and temporal magnitude and intensity of droughts. Our results show that the regional climate has become warmer and drier, due to the combined effects of increases in temperatures, sunshine duration, and the decrease in relative humidity and precipitation, variables that are likely to play an important role in drought. Unknown in the 60s, 70s and most of the 80s, drought has become a relatively frequent phenomenon during the last two decades, and, in fact, the two most extreme episodes of drought at century scale, during 1989-1990 and 1993, occur in the 90. However, both the frequency and the intensity of "Suradas" have reduced, and consequently, the high fire risk episodes are now less frequent, but their absolute maximum values remain unchanged. Those regional climate trends are strongly

  2. Estimating the Rate of Occurrence of Renal Stones in Astronauts

    NASA Technical Reports Server (NTRS)

    Myers, J.; Goodenow, D.; Gokoglu, S.; Kassemi, M.

    2016-01-01

    Changes in urine chemistry, during and post flight, potentially increases the risk of renal stones in astronauts. Although much is known about the effects of space flight on urine chemistry, no inflight incidence of renal stones in US astronauts exists and the question "How much does this risk change with space flight?" remains difficult to accurately quantify. In this discussion, we tackle this question utilizing a combination of deterministic and probabilistic modeling that implements the physics behind free stone growth and agglomeration, speciation of urine chemistry and published observations of population renal stone incidences to estimate changes in the rate of renal stone presentation. The modeling process utilizes a Population Balance Equation based model developed in the companion IWS abstract by Kassemi et al. (2016) to evaluate the maximum growth and agglomeration potential from a specified set of urine chemistry values. Changes in renal stone occurrence rates are obtained from this model in a probabilistic simulation that interrogates the range of possible urine chemistries using Monte Carlo techniques. Subsequently, each randomly sampled urine chemistry undergoes speciation analysis using the well-established Joint Expert Speciation System (JESS) code to calculate critical values, such as ionic strength and relative supersaturation. The Kassemi model utilizes this information to predict the mean and maximum stone size. We close the assessment loop by using a transfer function that estimates the rate of stone formation from combining the relative supersaturation and both the mean and maximum free stone growth sizes. The transfer function is established by a simulation analysis which combines population stone formation rates and Poisson regression. Training this transfer function requires using the output of the aforementioned assessment steps with inputs from known non-stone-former and known stone-former urine chemistries. Established in a Monte Carlo

  3. Rainfall projections relating to extratropical cyclone occurrence in eastern Australia

    NASA Astrophysics Data System (ADS)

    Dowdy, A. J.; Mills, G.; Timbal, B.; Wang, Y.

    2012-12-01

    The east coast of Australia is a region of the world where a particular type of extratropical cyclone, known locally as an East Coast Low, frequently occurs with severe consequences such as extreme rainfall, winds and waves. There is subjective evidence that the development of most major events is associated with the movement of a high amplitude upper-tropospheric trough system over eastern Australia. In order to test this hypothesis, a number of large-scale quantities in the upper-troposphere associated with extratropical cyclogenesis are applied to reanalyses and examined in relation to a database of observed East Coast Low events. A diagnostic quantity based on extreme values of cyclonic geostrophic vorticity is shown to provide a good indication of the likely occurrence of east-coast cyclogenesis, including seasonal and geographic variations. This diagnostic is then applied to three reanalyses and three global climate models (GCMs) to examine its applicability to GCM data, including the influence of model resolution on the diagnostic method. Strong similarities exist among the results derived from the individual reanalyses in terms of their seasonal variability (e.g. winter maxima and summer minima), interannual variability and spatial variability. Results obtained when applying the diagnostic to two of the three GCMs are similar to expectations given their spatial resolutions, with results from these two GCM-derived climatologies both indicating a reduction in the risk of extratropical cyclone occurrence of about 30% from the late 20th century to the late 21st century in subtropical eastern Australia (Fig. 1). Heavy rainfall and river inflow events, based on observations, are found to be well-represented by the diagnostic method applied to reanalyses. When applied to GCM simulations of the current and future climate, the diagnostic suggests that increased greenhouse gas forcing could be expected to lead to fewer heavy rainfall events associated with

  4. Occurrence of virus-induced COPD exacerbations during four seasons.

    PubMed

    Djamin, Remco S; Uzun, Sevim; Snelders, Eveline; Kluytmans, Jan J W; Hoogsteden, Henk C; Aerts, Joachim G J V; Van Der Eerden, Menno M

    2015-02-01

    In this study, we investigated the occurrence of viral infections in acute exacerbations of chronic obstructive pulmonary disease (COPD) during four seasons. Viral infections were detected by the use of real-time reverse transcriptase polymerase chain reaction on pharyngeal swabs. During a 12-month period pharyngeal swabs were obtained in 136 exacerbations of 63 patients. In 35 exacerbations (25.7%) a viral infection was detected. Most viral infections occurred in the winter (n = 14, 40.0%), followed by summer (n = 9, 25.7%), autumn (n = 6, 17.1%), and spring (n = 6, 17.1%). Rhinovirus was the most frequently isolated virus (n = 19, 51.4%), followed by respiratory syncytial virus (n = 6, 16.2%), human metapneumovirus (n = 5, 13.5%), influenza A (n = 4, 10.8%), parainfluenza 4 (n = 2, 5.4%), and parainfluenza 3 (n = 1, 2.7%). This study showed that virus-induced COPD exacerbations occur in all four seasons with a peak in the winter months. However, the distribution of rhinovirus infections showed a different pattern, with most infections occurring in July.

  5. The impact of climate change on persistent contrail occurrence

    NASA Astrophysics Data System (ADS)

    Irvine, Emma; Shine, Keith; Stringer, Marc

    2016-04-01

    The formation of persistent contrails by aircraft flying through cold ice-supersaturated (CISS) regions contributes to anthropogenic climate change. However, as the climate itself changes during the 21st century, the potential for the formation of persistent contrails may also change. We recently (doi: 10.5194/esd-6-555-2015) found a global-mean decrease in the frequency of CISS regions of one third (11 to 7%) by the end of the 21st century, relative to present-day conditions, using climate model data from CMIP5. This decrease is dominated by the large decrease in CISS frequency in the tropics where the models predict strong upper-tropospheric warming, to levels above the threshold temperature at which contrails can form. The situation for the northern hemisphere mid-latitudes is less clear and dependent on model, latitude and season. Actual changes to contrail cover during this period will depend also on flight routing. An example is shown for the north Atlantic, where aircraft routing is strongly wind-dependent and therefore will be affected by changes to the jet stream. Here we combine our analysis of changes in CISS with projected changes in aircraft routes (which are calculated using the climate model winds), to estimate the net impact on persistent contrail occurrence in this region. We distinguish between the effect on eastbound flights, which generally aim to exploit the jet stream, and westbound flights that aim to avoid it.

  6. Occurrence of Giardia and Cryptosporidium spp. in surface water supplies.

    PubMed Central

    LeChevallier, M W; Norton, W D; Lee, R G

    1991-01-01

    Giardia and Cryptosporidium levels were determined by using a combined immunofluorescence test for source waters of 66 surface water treatment plants in 14 states and 1 Canadian province. The results showed that cysts and oocysts were widely dispersed in the aquatic environment. Giardia spp. were detected in 81% of the raw water samples. Cryptosporidium spp. were found in 87% of the raw water locations. Overall, Giardia or Cryptosporidium spp. were detected in 97% of the raw water samples. Higher cyst and oocyst densities were associated with source waters receiving industrial or sewage effluents. Significant correlations were found between Giardia and Cryptosporidium densities and raw water quality parameters such as turbidity and total and fecal coliform levels. Statistical modeling suggests that cyst and oocyst densities could be predicted on the basis of watershed and water quality characteristics. The occurrence of high levels of Giardia cysts in raw water samples may require water utilities to apply treatment beyond that outlined in the Surface Water Treatment Rule of the U.S. Environmental Protection Agency. PMID:1822675

  7. Occurrence of acrylamide in selected foods and mitigation options.

    PubMed

    Amrein, Thomas M; Andres, Luca; Escher, Felix; Amadò, Renato

    2007-01-01

    Acrylamide reduction in certain food products is an important issue for both the food industry and academic research institutions. The present paper summarises past and current research on the occurrence and reduction of acrylamide in potatoes, bakery products, almonds, olives and dried fruit. In potatoes, the control of reducing sugars, process temperature and moisture is imperative to limit acrylamide formation. In bakery products, free asparagine and the type of baking agent largely determine acrylamide formation and present the starting points for reduction. The application of asparaginase is promising in this respect because it acts only on the key precursor, asparagine, whereby the product character remains unchanged. The baking agent NH4HCO3 promotes acrylamide formation in sweet bakery but its replacement by NaHCO3 effectively decreases acrylamide concentrations. Temperature and free asparagine are the key factors for acrylamide formation in roasted almonds. Olives and dried fruit may contain acrylamide and large amounts of acrylamide can be formed upon heating these products, a phenomenon which needs further investigation.

  8. Occurrence of acrylamide in selected foods and mitigation options.

    PubMed

    Amrein, Thomas M; Andres, Luca; Escher, Felix; Amadò, Renato

    2007-01-01

    Acrylamide reduction in certain food products is an important issue for both the food industry and academic research institutions. The present paper summarises past and current research on the occurrence and reduction of acrylamide in potatoes, bakery products, almonds, olives and dried fruit. In potatoes, the control of reducing sugars, process temperature and moisture is imperative to limit acrylamide formation. In bakery products, free asparagine and the type of baking agent largely determine acrylamide formation and present the starting points for reduction. The application of asparaginase is promising in this respect because it acts only on the key precursor, asparagine, whereby the product character remains unchanged. The baking agent NH4HCO3 promotes acrylamide formation in sweet bakery but its replacement by NaHCO3 effectively decreases acrylamide concentrations. Temperature and free asparagine are the key factors for acrylamide formation in roasted almonds. Olives and dried fruit may contain acrylamide and large amounts of acrylamide can be formed upon heating these products, a phenomenon which needs further investigation. PMID:17687696

  9. Occurrence of periodontal pathogens among patients with chronic periodontitis

    PubMed Central

    Farias, B.C.; Souza, P.R.E.; Ferreira, B.; Melo, R.S.A.; Machado, F.B.; Gusmão, E.S.; Cimões, R.

    2012-01-01

    The aim of the present study was to evaluate the presence of the periodontal pathogens that form the red complex (Tannerella forsythia, Porphyromonas gingivalis and Treponema denticola) and Aggregatibacter actinomycetemcomitans in patients with chronic periodontitis. The sample consisted of 29 patients with a clinical and radiographic diagnosis of chronic periodontitis based on the criteria of the American Academy of Periodontology (3). Samples for microbiological analysis were collected from the four sites of greatest probing depth in each patient, totaling 116 samples. These samples were processed using conventional polymerase chain reaction, which achieved the following positive results: 46.6% for P. gingivalis, 41.4% for T. forsythia, 33.6% for T. denticola and 27.6% for A. actinomycetemcomitans. P. gingivalis and T. forsythia were more prevalent (p < 0.05) in periodontal pockets ≥ 8 mm. The combinations T. forsythia + P. gingivalis (23.2%) and T. forsythia + P. gingivalis + T. denticola (20.0%) were more frequent in sites with a probing depth ≥ 8 mm. Associations with the simultaneous presence of A. actinomycetemcomitans + P. gingivalis, A. actinomycetemcomitans + T. forsythia, P. gingivalis + T. forsythia and T. forsythia + T. denticola were statistically significant (p < 0.05). It was concluded that the red complex pathogens are related to chronic periodontitis, presenting a higher occurrence in deep periodontal pockets. Moreover, the simultaneous presence of these bacteria in deep sites suggests a symbiotic relationship between these virulent species, favoring, in this way, a further progression of periodontal disease. PMID:24031906

  10. Occurrence of household mold and efficacy of sodium hypochlorite disinfectant.

    PubMed

    Reynolds, Kelly A; Boone, Stephanie; Bright, Kelly R; Gerba, Charles P

    2012-01-01

    The occurrence and distribution of mold on household surfaces and the efficacy of bleach-based (sodium hypochlorite, NaOCl) disinfectants on mold viability and allergenicity was documented. Household microenvironments prone to increased moisture were specifically targeted. Using the sticky tape method, 1330 samples were collected from non-porous indoor surfaces of 160 homes across the United States, and analyzed for mold. Homes were randomly selected and recruited via phone interviews. Culture and immunoassays were used to measure the viability and reduction of allergenic properties of Aspergillus fumigatus following 2.4% NaOCl treatment. All homes and 72.9% of surfaces tested positive for mold. Windowsills were the most frequently contaminated site (87.5%) and Cladosporium the most commonly identified mold (31.0%). Five-minute exposures to 2.4% NaOCl resulted in a >3 to >6-log₁₀ reduction of culturable mold counts in controlled laboratory studies. Organisms were nonculturable after 5- and 10-min contact times on non-porous and porous ceramic carriers, respectively, and A. fumigatus spore-eluted allergen levels were reduced by an average 95.8% in 30 sec, as indicated by immunoassay. All homes are contaminated with some level of mold, and regrowth is likely in moisture-prone microenvironments. The use of low concentrations (2.4%) of NaOCl for the reduction of culturable indoor mold and related allergens is effective and recommended.

  11. Occurrence of polychlorinated terphenyls (PCTs) in indoor particulate matter.

    PubMed Central

    Seidel, U; Schweizer, E; Schweinsberg, F; Wodarz, R; Rettenmeier, A W

    1996-01-01

    In the course of a routine investigation concerned with polychlorinated biphenyl (PCB) contamination of dust collected in classrooms of a junior high school, a group of electron capture detector (ECD)-sensitive compounds with high boiling points were found in addition to PCBs. Using gas chromatographic-mass spectrometric techniques, these compounds were identified as polychlorinated terphenyls (PCTs). Additional measurements indicated that the PCTs were present only in particulate matter collected from the tops of fluorescent light frames but not in air samples obtained concomitantly in the classrooms. Attempts to identify the PCT emission source were unsuccessful. A survey of the literature revealed that PCTs are ubiquitously distributed environmental contaminants, although no data on their indoor occurrence have been reported to date. In view of the toxic effects of PCTs, which seem to be as important as those of PCBs, further attention should be given to the possible presence of PCTs in indoor environments. Images Figure 1. Figure 2. Figure 3. Figure 4. PMID:8959406

  12. Winter habitat occurrence patterns of temperate migrant birds in Belize

    USGS Publications Warehouse

    Dawson, D.K.; Robbins, C.S.; Sauer, J.R.

    1992-01-01

    We used mist nets and point counts to sample bird populations in 61 sites in Belize during January-March of 1987-1991. Sites were classified as forest, second growth, woody agricultural crops (citrus, mango, cacao, and cashew), or non-woody agricultural crops (rice and sugar cane). We evaluated patterns of occurence of wintering temperate migrant bird species in these habitats. Mist net captures of 22 of 31 migrant species differed significantly among habitats. Of these, 13 species were captured more frequently in the agricultural habitats. American Redstart (Setophaga ruticilla), Black-and-white Warbler (Mniotilta varia), and Magnolia Warbler (Dendroica magnolia) were among the species captured most frequently in woody agricultural habitats; captures of Common Yellowthroat (Geothlypis trichas), Indigo Bunting (Passerina cyanea), and Northern (lcterus galbula) and Orchard orioles (I. spur/anus) were highest in the non-woody agricultural sites. We relate these occurrence patterns to trends in breeding populations in North America. While count data provide a wide picture of winter habitat distribution of migrants, more intensive work is necessary to assess temporal and geographic variation of migrant bird use of agricultural habitats.

  13. Hydrous silica coatings: occurrence, speciation of metals, and environmental significance.

    PubMed

    Schindler, Michael; Durocher, Jennifer L; Abdu, Yassir; Hawthorne, Frank C

    2009-12-01

    Si-enriched coatings form on the surface of silicate minerals under acidic conditions. Although they are often only a few nanometers thick, their large specific surface area may control the interaction between silicate minerals in acidic soils, aquifers, and mine tailings. Micrometer thick, hydrous-silica coatings occur on the surface of a granite outcrop in contact with acidic pond water at the Coppercliff mine-tailings area in the Greater City of Sudbury, Ontario, and are ideal to study the concentration and speciation of metals and metalloids inside Si-enriched coatings. These coatings have higher average concentrations of Cr, Mn, Co, Ni, Cu, Zn, and Pb than coatings composed of schwertmannite, Fe(8)O(8)(OH)(4.4)(SO(4))(1.8) (H(2)O)(8.4). Microscopic and spectroscopic examination of the hydrous-silica coating indicates the occurrence of Fe- and Cu-Zn-oxy-hydroxide particles, tetrahedrally coordinated Fe(3+) and a high proportion of M-O-Si bonds (M = metal). These observations suggest that metals occur either finely distributed in the hydrous-silica matrix or in oxy-hydroxide particles. The latter particles are products of the diffusion of metals into the hydrous silica and the subsequent nucleation of oxy-hydroxide phases.

  14. Occurrence and prevalence of antibiotic resistance in landfill leachate.

    PubMed

    Wang, Yangqing; Tang, Wei; Qiao, Jing; Song, Liyan

    2015-08-01

    Antibiotic resistance (AR) is extensively present in various environments, posing emerging threat to public and environmental health. Landfill receives unused and unwanted antibiotics through household waste and AR within waste (e.g., activated sludge and illegal clinical waste) and is supposed to serve as an important AR reservoir. In this study, we used culture-dependent methods and quantitative molecular techniques to detect and quantify antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in 12 landfill leachate samples from six geographic different landfills, China. Five tested ARGs (tetO, tetW, bla(TEM), sulI, and sulII) and seven kinds of antibiotic-resistant heterotrophic ARB were extensively detected in all samples, demonstrating their occurrence in landfill. The detected high ratio (10(-2) to 10(-5)) of ARGs to 16S ribosomal RNA (rRNA) gene copies implied that ARGs are prevalent in landfill. Correlation analysis showed that ARGs (tetO, tetW, sulI, and sulII) significantly correlated to ambient bacterial 16S rRNA gene copies, suggesting that the abundance of bacteria in landfill leachate may play an important role in the horizontal spread of ARGs.

  15. Occurrence and Antibiotic Susceptibility of Listeria Species in Turkey Meats

    PubMed Central

    Ardıç, Mustafa

    2015-01-01

    The aims of this study were to investigate the occurrence of Listeria species in turkey meats and to check the antimicrobial susceptibility of the isolated strains. Hundred and fifteen raw turkey meat samples were randomly collected from the supermarkets, butchers and restaurants. Strain isolation and identification were made according to the ISO11290-1 method. Antimicrobial susceptibility was determined by the standard disc diffusion method. A total of 47 Listeria spp. were isolated from 115 (40.9%) raw turkey meat samples. The isolates were distributed between L. monocytogenes (25.53%), L. innocua (34.04%), L. grayi (31.91%) and L. welshimeri (8.51%). A total of 55.3 % of Listeria spp. isolates were multi-resistant to at least 3 of the antimicrobial agent tested. The level of multi-resistance was higher in L. monocytogenes strains (66.7%) than in L. innocua (62.5%) and L. grayi (53.3%). Listeria spp. isolates were highly resistant to ampicillin, cephalothin, penicillin, meticillin, oxacillin, and trimethoprime-sulfamethoxazole. The isolates particularly L. monocytogenes are increasingly resistant to one or more antibiotics and may represent a potential risk for public health because these antibiotics are common used in treatment of listeriosis. The correct and controlled use of antibiotics in veterinary medicine is important to the emergence of resistant strains. PMID:26761896

  16. Folate receptor gene variants and neural tube defect occurrence

    SciTech Connect

    Finnell, R.; Greer, K.; Lammer, E.

    1994-09-01

    Recent epidemiological evidence shows that periconceptional use of folic acid supplements may prevent 40-50% of neural tube defects (NTDs). The FDA has subsequently recommended folic acid supplementation of all women of childbearing potential, even though the mechanism by which folic acid prevents NTDs is unknown. We investigated genetic variation of a candidate gene, the 5-methyltetrahydrofolate (5-MeTHF) receptor, that may mediate this preventive effect. The receptor concentrates folate within cells and we have localized its mRNA to neuroepithelial cells during neurulation. Our hypothesis is that dysfunctional 5-MeTHF receptors inadequately concentrate folate intracellularly, predisposing infants to NTDs. We have completed SSCP analysis on 3 of the 4 coding exons of the 5-MeTHF receptor gene of 474 infants participating in a large population-based epidemiological case-control study of NTDs in California; genotyping of another 500 infants is ongoing. Genomic DNA was extracted from residual blood spots from newborn screening samples of cases and controls. Genotyping was done blinded to case status. Polymorphisms have been detected for exons 4 and 5; fourteen percent of the infants have exon 5 polymorphisms. Data will be presented on the prevalence of 5-MeTHF receptor polymorphisms among cases and controls. Relationships among the polymorphisms and NTD occurrence may shed light on how folic acid supplementation prevents NTDs.

  17. Groundwater occurrence in cold environments: examples from Nunavik, Canada

    NASA Astrophysics Data System (ADS)

    Lemieux, Jean-Michel; Fortier, Richard; Talbot-Poulin, Marie-Catherine; Molson, John; Therrien, René; Ouellet, Michel; Banville, David; Cochand, Marion; Murray, Renaud

    2016-04-01

    Water availability and management issues related to the supply of drinking water in northern communities are problematic in Canada. While rivers and lakes are abundant, they are vulnerable to contamination and may become dry in winter due to freezing. Groundwater can often provide a more secure and sustainable water source, however its availability is limited in northern Canada due to the presence of permafrost. Moreover, the exploitation of northern aquifers poses a dual challenge of identifying not only permafrost-free areas, but also permeable areas which will allow groundwater recharge and exploitation. Suitable aquifers are not as common in northern Canada since the shallow subsurface is mostly composed of low-permeability crystalline rocks or unconsolidated sediments of glacial origin that are highly heterogeneous. In order to investigate groundwater occurrence and associated geological contexts in Nunavik (northern Quebec, Canada), along with exploring how these resources will evolve in response to climate change, field and compilation work were conducted in the surroundings of the four villages of Salluit, Kuujjuaq, Umiujaq and Whapmagoostui-Kuujjuarapik. These villages are located in different permafrost zones, ranging from continuous to discontinuous, as well as in different geological environments. It was found that despite the ubiquitous presence of permafrost, unfrozen aquifers could be identified, which suggests that groundwater may be available as a source of drinking water for small communities. Expected climate change, with predicted permafrost thawing and increases in temperature and precipitation, should enhance groundwater availability and may contribute to a more secure source of drinking water for northern communities.

  18. Occurrence and distribution of benzothiazole in the Schwarzbach watershed (Germany).

    PubMed

    Fries, Elke; Gocht, Tilman; Klasmeier, Jörg

    2011-10-01

    This study quantifies the regional distribution of the micropollutant benzothiazole (BT) in river water by sampling 15 river sites in the Schwarzbach watershed (about 400 km(2)) from November 2008 to February 2010. Additionally, wastewater samples from three municipal wastewater treatment plants (WWTPs) in Germany were analyzed. BT was detected in all wastewater influent and effluent samples as well as in all river water samples collected downstream of wastewater discharge. This corroborates the ubiquitous occurrence of BT in the aqueous environment. Concentrations were between 58 and 856 ng L(-1) in the river water. The observed mean concentration at the outlet of the investigated catchment was 109 ng L(-1). With only a few exceptions, temporal and spatial variations of BT concentrations in river water were low. Rather similar BT concentrations over a wide range of river discharge indicate that dilution along the mainstream is negligible and, thus, supports the hypothesis that paved surface runoff during rain events is an important BT source not only for wastewater influent but also for river water. This was supported by detecting the highest BT concentrations at sampling locations close to the dense highway network around the city of Frankfurt. Since BT was also detected in river water collected from locations that were clearly unaffected by wastewater effluent discharge, surface runoff must be considered as a diffuse source of BT in river water.

  19. Occurrence and treatment of wastewater-derived organic nitrogen.

    PubMed

    Chen, Baiyang; Kim, Youngil; Westerhoff, Paul

    2011-10-01

    Dissolved organic nitrogen (DON) derived from wastewater effluent can participate in reactions that lead to formation of nitrogenous chlorination by-products, membrane fouling, eutrophication, and nitrification issues, so management of DON is important for both wastewater reuse applications and nutrient-sensitive watersheds that receive discharges from treated wastewater. This study documents DON occurrence in full-scale water/wastewater (W/WW) treatment plant effluents and assesses the removal of wastewater-derived DON by several processes (biodegradation, coagulation, softening, and powdered activated carbon [PAC] adsorption) used for advanced treatment in wastewater reuse applications. After varying levels of wastewater treatment, the dominant aqueous nitrogenous species shifts from ammonia to nitrate after aerobic processes and nitrate to DON in tertiary treatment effluents. The fraction of DON in total dissolved nitrogen (TDN) accounts for at most 52% in tertiary treated effluents (median=13%) and 54% in surface waters impacted by upstream wastewater discharges (median=31%). The 5-day biodegradability/bioavailability of DON (39%) was higher, on average, than that of dissolved organic carbon (DOC, 26%); however, upon chlorination, the DON removal (3%) decreased significantly. Alum coagulation (with ≥8 mg/L alum per mg/L DOC) and lime softening (with pH 11.3-11.5) removed<25% of DON and DOC without selectivity. PAC adsorption preferentially removed more DOC than DON by 10% on average. The results provided herein hence shed light on approaches for reducing organic nitrogen content in treated wastewater. PMID:21741064

  20. Occurrence of Clostridium perfringens from different cultivated soils.

    PubMed

    Voidarou, C; Bezirtzoglou, E; Alexopoulos, A; Plessas, S; Stefanis, C; Papadopoulos, I; Vavias, S; Stavropoulou, E; Fotou, K; Tzora, A; Skoufos, I

    2011-12-01

    The occurrence of Clostridium perfringens was estimated in 750 samples originated from a variety of soils bearing various bulb crops: Brawnica oderacea (vegetable), Olea europaea, Daucus carota (carote), Solanum tuberosum (potato), Phaseolus vulgaris (green haricot), Beta vulgaris var. rapaceum (beetroot), Cucurbita pepo (squash), Allium cepa (onion), Cucumis sativus (cucumber) and Capsicum annum (pepper). All isolated strains were tested for their antimicrobial activities to amoxicillin, penicillin G, kanamycin, tetracycline, streptomycin, erythromycin, chloramphenicol and metronidazole. When considering the type of the bulb production, it was observed increased number of C. perfringens spore densities in the most undersurface bulb soils. Moreover, C. perfringens spore are likely to occur in particularly large numbers in soil contaminated by fecal matter. Additionally, there is a close relationship between the spore amount and nature of organic content. Presence of C. perfringens was associated with acidic soil. Most of our strains showed resistance to the studied antibiotics applied usually for human and veterinary care. A systematic monitoring of the cultivated soil ecosystems must include bacteriological parameters together with chemical indices of organic pollution in order to obtain information adequate for assessing their overall quality. PMID:21621626

  1. The frequency and duration of dew occurrence over a year.

    NASA Astrophysics Data System (ADS)

    Janssen, L. H. J. M.; Römer, F. G.

    1991-11-01

    In this paper, a new dew model is presented which is easy to apply and requires only a very limited amount of synoptic data, viz., cloud cover, relative humidity, air temperature and wind velocity. In the dew model, the contribution of the fluxes of infrared radiation, sensible and latent heat to the energy balance of a dew plate are parametarised according to detailed micrometeorological measurements of Holtslag and De Bruin. The model is tested with measurements of dew on the glass surface of an automatic sequential dew sampler. Results of model calculations and measurements of dew occurrence show a fairly close correspondence. The frequency and duration of dew deposition over a year, for 3 places in the Netherlands, have been calculated with the model, using only synoptic data. The numbers of dewy nights and dewy hours were calculated for the year 1987. This resulted in about 220 dewy nights and 1600 dewy hours. Taking the hours of rain into account, it appears that about 75% of the time a surface is wet during the nocturnal hours because of dew or rain. This fact may be important for the quantification of the dry deposition of easily soluble air pollutants and for the effect of air pollutants on vegetation.

  2. Regional analysis of earthquake occurrence and seismic energy release

    NASA Technical Reports Server (NTRS)

    Cohen, S. C.

    1980-01-01

    The historic temporal variation in earthquake occurrence and seismic energy release on a regional basis throughtout the world were studied. The regionalization scheme employed divided the world into large areas based either on seismic and tectonic considerations (Flinn-Engdahl Scheme) or geographic (longitude and latitude) criteria. The data set is the wide earthquake catalog of the National Geophysical Solar-Terrestrial Data Center. An apparent relationship exists between the maximum energy released in a limited time within a seismic region and the average or background energy per year averaged over a long time period. In terms of average or peak energy release, the most seismic regions of the world during the 50 to 81 year period ending in 1977 were Japanese, Andean South American, and the Alaska-Aleutian Arc regions. The year to year fluctuations in regional seismic energy release are greater, by orders of magnitude, than the corresponding variations in the world-wide seismic energy release. The b values of seismic regions range from 0.7 to 1.4 where earthquake magnitude is in the range 6.0 to 7.5.

  3. Occurrence of Stachybotrys chartarum chemotype S in dried culinary herbs.

    PubMed

    Biermaier, Barbara; Gottschalk, Christoph; Schwaiger, Karin; Gareis, Manfred

    2015-02-01

    Stachybotrys (S.) chartarum is an omnipresent cellulolytic mould which produces secondary metabolites, such as the highly toxic macrocyclic trichothecenes. While it is known to occur in animal feed like hay and straw as well as in water-damaged indoor environments, there is little knowledge about the occurrence of S. chartarum and its secondary metabolites in food. The objective of the present study was to examine selected dried culinary herbs for the presence of S. chartarum chemotype S, to assess the potential risk of a contamination of foods with macrocyclic trichothecenes. In total, 50 Stachybotrys isolates from different types of culinary herbs (n=100) such as marjoram (Origanum majorana Linné (L.)), oregano (Origanum vulgare L.), thyme (Thymus vulgaris L.), and savory (Satureja hortensis L.) were examined by MTT-cell culture test (effect-based bioassay), ELISA, and by liquid chromatography tandem mass spectrometry (LC-MS/MS). Selected toxic and non-toxic isolates (n=15) were genetically characterized by PCR and sequencing. Five isolates (10%) were highly toxic in the MTT-cell culture test, and the production of macrocyclic trichothecenes was proven by ELISA and LC-MS/MS. These five isolates were genetically confirmed as S. chartarum chemotype S. To the best of our knowledge, this is the first report about a contamination of dried culinary herbs with toxigenic S. chartarum. PMID:25346283

  4. Widespread occurrence of (per)chlorate in the Solar System

    NASA Astrophysics Data System (ADS)

    Jackson, W. Andrew; Davila, Alfonso F.; Sears, Derek W. G.; Coates, John D.; McKay, Christopher P.; Brundrett, Maeghan; Estrada, Nubia; Böhlke, J. K.

    2015-11-01

    Perchlorate (ClO4-) and chlorate (ClO3-) are ubiquitous on Earth and ClO4- has also been found on Mars. These species can play important roles in geochemical processes such as oxidation of organic matter and as biological electron acceptors, and are also indicators of important photochemical reactions involving oxyanions; on Mars they could be relevant for human habitability both in terms of in situ resource utilization and potential human health effects. For the first time, we extracted, detected and quantified ClO4- and ClO3- in extraterrestrial, non-planetary samples: regolith and rock samples from the Moon, and two chondrite meteorites (Murchison and Fayetteville). Lunar samples were collected by astronauts during the Apollo program, and meteorite samples were recovered immediately after their fall. This fact, together with the heterogeneous distribution of ClO4- and ClO3- within some of the samples, and their relative abundance with respect to other soluble species (e.g., NO3-) are consistent with an extraterrestrial origin of the oxychlorine species. Our results, combined with the previously reported widespread occurrence on Earth and Mars, indicate that ClO4- and ClO3- could be present throughout the Solar System.

  5. Pentahydroxyscirpene—Producing Strains, Formation In Planta, and Natural Occurrence

    PubMed Central

    Varga, Elisabeth; Wiesenberger, Gerlinde; Fruhmann, Philipp; Malachová, Alexandra; Svoboda, Thomas; Lemmens, Marc; Adam, Gerhard; Berthiller, Franz

    2016-01-01

    Trichothecenes are a class of structurally diverse mycotoxins with more than 200 naturally occurring compounds. Previously, a new compound, pentahydroxyscirpene (PHS), was reported as a byproduct of a nivalenol producing Fusarium strain, IFA189. PHS contains a hydroxy group at C-8 instead of the keto group of type B trichothecenes. In this work, we demonstrate that IFA189 belongs to the species Fusarium kyushuense using molecular tools. Production of PHS in vitro was also observed for several isolates of other Fusarium species producing nivalenol. Furthermore, we report the formation of 4-acetyl-PHS by F. kyushuense on inoculated rice. Wheat ears of the variety Remus were infected with IFA189 and the in planta production of PHS was confirmed. Natural occurrence of PHS was verified in barley samples from the Czech Republic using a liquid chromatographic-tandem mass spectrometric method validated for this purpose. Toxicity of PHS to wheat ribosomes was evaluated with a coupled in vitro transcription and translation assay, which showed that PHS inhibits protein biosynthesis slightly less than nivalenol and deoxynivalenol. PMID:27754401

  6. Modelling occurrence and abundance of species when detection is imperfect

    USGS Publications Warehouse

    Royle, J. Andrew; Nichols, J.D.; Kery, M.

    2005-01-01

    Relationships between species abundance and occupancy are of considerable interest in metapopulation biology and in macroecology. Such relationships may be described concisely using probability models that characterize variation in abundance of a species. However, estimation of the parameters of these models in most ecological problems is impaired by imperfect detection. When organisms are detected imperfectly, observed counts are biased estimates of true abundance, and this induces bias in stated occupancy or occurrence probability. In this paper we consider a class of models that enable estimation of abundance/occupancy relationships from counts of organisms that result from surveys in which detection is imperfect. Under such models, parameter estimation and inference are based on conventional likelihood methods. We provide an application of these models to geographically extensive breeding bird survey data in which alternative models of abundance are considered that include factors that influence variation in abundance and detectability. Using these models, we produce estimates of abundance and occupancy maps that honor important sources of spatial variation in avian abundance and provide clearly interpretable characterizations of abundance and occupancy adjusted for imperfect detection.

  7. Polygenetic pyritic gold occurrences in Bousquet Township, Quebec

    SciTech Connect

    Valliant, R.I.; Stone, W.E.

    1985-01-01

    Bousquet Township contains stratiform and stratabound pyritic gold deposits and gold-bearing quartz veins within volcaniclastic sedimentary rocks, felsic volcanic rocks and a granitoid stock on the south side of the Abitibi Greenstone Belt, 50 km east of Noranda, Quebec. Bousquet number3 is a large stratiform lens of fine grained gold in layered disseminated and massive pyrite with minor telluride and base metal sulfide minerals. The enclosing rock consists of quartz and muscovite with accessory andalusite, corundum, paragonite, chloritoid, and manganiferous garnet. Bousquet number5 and Doyon number2 are large stratabound lenses of fine grained gold with disseminated pyrite on a cleavage penetrating a rock of quartz, muscovite, chlorite and carbonate. The vein deposits are relatively small and have gold with quartz, pyrite, and chalcopyrite which crosscut the Doyon number2 lens and the granitoid stock. The stratiform, stratabound, and vein deposits record a progressive metallogenic event coeval with deposition and deformation of the enveloping rocks. The stratiform deposits are interpreted as products of exhalative activity accompanying felsic volcanism. Stratabound occurrences are interpreted as successively modified variations of the stratiform deposits or, as gold introduced during deformation which is synchronous with or after volcanism. The vein deposits represent waning stages of hydrothermal fluid circulation accompanying crystallization of the granitoid stock toward the end of volcanic activity in the district.

  8. West syndrome followed by juvenile myoclonic epilepsy: a coincidental occurrence?

    PubMed Central

    2013-01-01

    Background West syndrome is an age-dependent epilepsy with onset peak in the first year of life whose aetiology may be symptomatic or cryptogenic. Long-term cognitive and neurological prognosis is usually poor and seizure outcome is also variable. Over the past two decades a few patients with favourable cognitive outcome and with total recovery from seizures were identified among the cryptogenic group suggesting an idiopathic aetiology. Recent research has described two children with idiopathic WS who later developed a childhood absence epilepsy. Case presentation We reviewed the medical records of patients with West syndrome admitted to the our Child Neuropsychiatry Unit in the last 15 years in order to know the clinical evolution of infantile spasms. We report a child with West syndrome with onset at 8 months of age followed by some clusters of bilateral, arrhythmic myoclonic jerks of the upper limbs, mainly on awakening, synchronous with the generalized discharges of 4 Hz spike-wave occurring at 12 years of age and by co-occurrence of a later generalized tonic-clonic seizure at 14 years and four months, both sensitive to Levetiracetam suggesting a juvenile myoclonic epilepsy. Conclusions This unusual evolution, never previously reported, suggests that both electroclinical features mentioned above may share some pathophysiological processes genetically determined which produce a susceptibility to seizure and emphasizes that the transition between different age-related epileptic phenotypes may involve also the West syndrome. PMID:23705971

  9. Occurrence of Bordetella Infection in Pigs in Northern India

    PubMed Central

    Kumar, Sandeep; Singh, Bhoj R.; Bhardwaj, Monika; Singh, Vidya

    2014-01-01

    Bordetella bronchiseptica infection causing atrophic rhinitis in pigs is reported from almost all countries. In the present study, occurrence of Bordetella infection in apparently healthy pigs was determined in 392 pigs sampled to collect 358 serum samples and 316 nasal swabs from Northern India by conventional bacterioscopy, detection of antigen with multiplex polymerase chain reaction (mPCR), and detection of antibodies with microagglutination test (MAT) and enzyme linked immune-sorbent assay (ELISA). Bordetella bronchiseptica could be isolated from six (1.92%) nasal swabs. Although isolates varied significantly in their antimicrobial sensitivity, they had similar plasmid profile. The genus specific and species specific amplicons were detected from 8.2% and 4.4% nasal swabs using mPCR with alc gene (genus specific) and fla gene and fim2 gene (species specific) primers, respectively. Observations revealed that there may be other bordetellae infecting pigs because about 50% of the samples positive using mPCR for genus specific amplicons failed to confirm presence of B. bronchiseptica. Of the pig sera tested with MAT and ELISA for Bordetella antibodies, 67.6% and 86.3% samples, respectively, were positive. For antigen detection mPCR was more sensitive than conventional bacterioscopy while for detection of antibodies neither of the two tests (MAT and ELISA) had specificity in relation to antigen detection. Study indicated high prevalence of infection in swine herds in Northern India. PMID:24688547

  10. Occurrence of taraxerol and taraxasterol in medicinal plants

    PubMed Central

    Sharma, Kiran; Zafar, Rasheeduz

    2015-01-01

    Indian soil germinates thousands of medicinal drugs that are cultivated with a purpose to obtain a novel drug. As it is a well-established fact that the structural analogs with greater pharmacological activity and fewer side-effects may be generated by the molecular modification of the functional groups of such lead compounds. This review throws light on two natural triterpenes - Taraxerol and Taraxasterol which have many important pharmacological actions including anti-cancer activity, their chemistry, biosynthesis aspects, and possible use of these compounds as drugs in treatment of cancer. A silent crisis persists in cancer treatment in developing countries, and it is intensifying every year. Although at least 50-60% of cancer victims can benefit from radiotherapy that destroys cancerous tumors, but search for the paramount therapy which will prove to be inexpensive with minimal side effects still persists. Various treatment modalities have been prescribed, along with conventional and non-conventional medicine but due to their adverse effects and dissatisfaction among users, these treatments are not satisfactory enough to give relief to patients. Hence, this review sparks the occurrence of Taraxerol (VI) and Taraxasterol (VII) in nature, so that the natural godowns may be harvested to obtain these potent compounds for novel drug development as well as discusses limitations of these lead compounds progressing clinical trials. PMID:26009688

  11. Occurrence of Antibiotics and Emerging Contaminants in Dairy Farming

    NASA Astrophysics Data System (ADS)

    Watanabe, N.; Harter, T.; Bergamaschi, B.

    2007-12-01

    Intense animal husbandry is of growing concern as a potential contamination source of a variety of emerging contaminants including pathogens, naturally occurring and synthetic steroid hormones, and various pharmaceuticals, particularly antibiotics. For example, more than twenty million pounds of antibiotics are sold for use in animal husbandry with 95% going towards therapeutic use. Here, we focus on the application and potential environmental occurrence of pharmaceuticals and disinfectants on dairies. Recommended drug applications are available from national databases. Statistical data on actual usage, however, are not available. We complement national data with interviews and dairy visits for further evaluation of drug and chemical usage (not including pesticides used on crops and fertilizer) and an overall assessment of the potential antibiotics output in dairy waste. We find that aminoglycosides, tetracyclines, and coccidiostats make up much of the total mass of antibiotics used. On dairies using the ionophoric antibiotic monensin as feed additive, monensin makes up a large fraction of the total antibiotics use (by mass). Other chemicals of potential concern include disinfectants used to prevent mastitis, detergents used in the milking parlor, footbath reagents to prevent and treat lameness, and insecticides used to control flies and mites.

  12. Agrichemicals in Nebraska, USA, watersheds: occurrence and endocrine effects.

    PubMed

    Sellin, Marlo K; Snow, Daniel D; Schwarz, Matthew; Carter, Barbara J; Kolok, Alan S

    2009-11-01

    The objective of the present study was to determine the occurrence and endocrine effects of agrichemicals in four Nebraska, USA, watersheds--the Elkhorn, Platte, Niobrara, and Dismal rivers. Land use in the Elkhorn River and Platte River watersheds is characterized by intense agriculture, including row crop and beef cattle production. In contrast, land within the Niobrara River and Dismal River watersheds consists primarily of grasslands. Polar organic chemical integrative samplers (POCIS) and caged fathead minnows were deployed at a site within each watershed for 7 d. The POCIS were analyzed for pesticides and hormones, while the caged minnows were analyzed for the expression of estrogen- and androgen-responsive genes. Amounts of pesticides recovered in POCIS extracts from the Elkhorn and Platte rivers were higher than those recovered from the Niobrara and Dismal rivers. Furthermore, female minnows deployed in the Elkhorn River experienced significant reductions in expression of two estrogen-responsive genes (vitellogenin and estrogen receptor α) relative to females deployed at the other sites, indicating alterations in endocrine function. However, the defeminization of these females could not be definitely linked to any of the agrichemicals detected in the POCIS recovered from the Elkhorn River.

  13. Periodicities in the occurrence rate of solar proton events

    NASA Technical Reports Server (NTRS)

    Gabriel, S.; Evans, R.; Feynman, J.

    1990-01-01

    Power spectral analyses of the time series of solar proton events during the past three solar cycles reveal a periodicity around 154 days. This feature is prominent in all of the cycles combined, cycles 19 and 21 individually, but is only weak in cycle 20. These results are consistent with the presence of similar periodicities between 152 and 155 days in the occurrence rate of major solar flares, the sunspot blocking function (Ps), the 10.7 cm radio flux (F10.7), and the sunspot number (Rz). This suggests that the circa 154-days periodicity may be a fundamental characteristic of the sun. Periods around 50-52 days are also found in the combined data set and in the three individual cycles, in general agreement with the detection of this periodicity in major flares in cycle 19, and in Ps, F10.7, and Rz in cycle 21. The cause of the 155 day period remains unknown. The spectra contain lines (or show power at frequencies) consistent with a model in which the periodicity is caused by differential rotation of active zones and a model in which it is related to beat frequencies between solar oscillations, as proposed by Wolff (1974, 1983).

  14. Occurrence of Bordetella infection in pigs in northern India.

    PubMed

    Kumar, Sandeep; Singh, Bhoj R; Bhardwaj, Monika; Singh, Vidya

    2014-01-01

    Bordetella bronchiseptica infection causing atrophic rhinitis in pigs is reported from almost all countries. In the present study, occurrence of Bordetella infection in apparently healthy pigs was determined in 392 pigs sampled to collect 358 serum samples and 316 nasal swabs from Northern India by conventional bacterioscopy, detection of antigen with multiplex polymerase chain reaction (mPCR), and detection of antibodies with microagglutination test (MAT) and enzyme linked immune-sorbent assay (ELISA). Bordetella bronchiseptica could be isolated from six (1.92%) nasal swabs. Although isolates varied significantly in their antimicrobial sensitivity, they had similar plasmid profile. The genus specific and species specific amplicons were detected from 8.2% and 4.4% nasal swabs using mPCR with alc gene (genus specific) and fla gene and fim2 gene (species specific) primers, respectively. Observations revealed that there may be other bordetellae infecting pigs because about 50% of the samples positive using mPCR for genus specific amplicons failed to confirm presence of B. bronchiseptica. Of the pig sera tested with MAT and ELISA for Bordetella antibodies, 67.6% and 86.3% samples, respectively, were positive. For antigen detection mPCR was more sensitive than conventional bacterioscopy while for detection of antibodies neither of the two tests (MAT and ELISA) had specificity in relation to antigen detection. Study indicated high prevalence of infection in swine herds in Northern India. PMID:24688547

  15. Occurrence of Legionella in groundwater: an ecological study.

    PubMed

    Riffard, S; Douglass, S; Brooks, T; Springthorpe, S; Filion, L G; Sattar, S A

    2001-01-01

    The natural habitat of Legionella is the water environment. Little is known about their presence in groundwater in spite of the fact that many millions around the globe regularly rely on groundwaters. This pilot study was aimed at evaluating the occurrence of Legionella in groundwater samples (water and biofilms) collected from various sites. Water and biofilm samples from selected groundwater sources were examined for Legionella using culture media (selective and non-selective) and a semi-nested PCR assay. Innovative approaches such as immunomagnetic separation (IMS) in combination with cultivation and flow cytometry were also evaluated. The findings available thus far show that (a) Legionella could be readily recovered from groundwater samples by cultivation even though their numbers showed considerable variations, (b) surprisingly, the PCR methodology was not yet as sensitive as cultivation and (c) flow cytometry was not directly applicable on natural samples because of debris and the high number of heterotrophic associated microflora from which some members were likely to cross-react with the monoclonal antibody used for separation procedures (IMS). PMID:11464778

  16. Mycobiota and co-occurrence of mycotoxins in Capsicum powder.

    PubMed

    Santos, L; Marín, S; Mateo, E M; Gil-Serna, J; Valle-Algarra, F M; Patiño, B; Ramos, A J

    2011-12-15

    This study aimed to: (1) determine the mycobiota of Capsicum powder samples, paying a special attention to the mycotoxigenic moulds; (2) evaluate the contamination levels of aflatoxins (AF), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), T2 and HT2 toxins in those samples. Thirty-two samples were obtained through the methods of sampling established by the European Union legislation. Aspergillus and Eurotium were the most frequently found genera. Aspergillus section Nigri had the higher relative frequency in the samples, A. niger aggregate being the most representative group of this section. Other potentially mycotoxigenic Aspergillus, Fusarium and Penicillium species were found, but in a lower frequency. Co-occurrence of mycotoxins was confirmed in the 32 Capsicum powder samples. All samples were contaminated with AF and OTA, 27% with ZEA (36% of chilli and 18% of paprika samples), 9% with DON (18% of chilli and 6% of paprika samples), 6% with T2 (18% of chilli samples) and none of the samples contained HT2. Although in the present study the most common genera found (Aspergillus and Eurotium) belong to storage moulds, some field fungi such as Fusarium spp. were also found, and their toxins were sometimes detected. This fact supports the hypothesis that mycotoxin contamination of Capsicum products may occur both in the field and/or during storage.

  17. Youth Exposed to Violence: Stability, Co-occurrence, and Context

    PubMed Central

    Margolin, Gayla; Vickerman, Katrina A.; Ramos, Michelle C.; Serrano, Sarah Duman; Gordis, Elana B.; Iturralde, Esti; Oliver, Pamella H.; Spies, Lauren A.

    2009-01-01

    With considerable literature establishing how separate types of violence disrupt the lives of children, there is emerging interest in examining violence across multiple interpersonal domains. This paper examines four commonly occurring and frequently researched domains of violence exposure: marital physical aggression, mother-to-youth aggression, father-to-youth aggression, and community violence. A community-based sample of 103 parents and youth provided three waves of data at annual intervals beginning when the youth were aged 9–10. We explored stability of exposure, co-occurrence across different types of violence exposure, and associations with co-occurring risk factors. Approximately 30–45% of youth reported intermittent exposure over the 3 years. In addition to overlap among types of violence exposure within the family, we found overlap between parent-to-youth aggression and community violence, an association that was exacerbated in families where fathers reported high levels of global distress symptoms. Mother-to-youth, father-to-youth, and community violence related to youth behavior problems beyond the contextual risk factors of low income, stressful life events, and parents’ global distress symptoms. These results highlight the importance of examining violence longitudinally, across multiple types, and with attention to contextual factors. PMID:19238543

  18. Groundwater occurrence in cold environments: examples from Nunavik, Canada

    NASA Astrophysics Data System (ADS)

    Lemieux, Jean-Michel; Fortier, Richard; Talbot-Poulin, Marie-Catherine; Molson, John; Therrien, René; Ouellet, Michel; Banville, David; Cochand, Marion; Murray, Renaud

    2016-09-01

    Water availability and management issues related to the supply of drinking water in northern communities are problematic in Canada. While rivers and lakes are abundant, they are vulnerable to contamination and may become dry in winter due to freezing. Groundwater can often provide a more secure and sustainable water source, however its availability is limited in northern Canada due to the presence of permafrost. Moreover, the exploitation of northern aquifers poses a dual challenge of identifying not only permafrost-free areas, but also permeable areas which will allow groundwater recharge and exploitation. Suitable aquifers are not as common in northern Canada since the shallow subsurface is mostly composed of low-permeability crystalline rocks or unconsolidated sediments of glacial origin that are highly heterogeneous. In order to investigate groundwater occurrence and associated geological contexts in Nunavik (northern Quebec, Canada), along with exploring how these resources will evolve in response to climate change, field and compilation work were conducted in the surroundings of the four villages of Salluit, Kuujjuaq, Umiujaq and Whapmagoostui-Kuujjuarapik. These villages are located in different permafrost zones, ranging from continuous to discontinuous, as well as in different geological environments. It was found that despite the ubiquitous presence of permafrost, unfrozen aquifers could be identified, which suggests that groundwater may be available as a source of drinking water for small communities. Expected climate change, with predicted permafrost thawing and increases in temperature and precipitation, should enhance groundwater availability and may contribute to a more secure source of drinking water for northern communities.

  19. Drought occurrence in the Alpine Region, 1864-2050

    NASA Astrophysics Data System (ADS)

    Calanca, P.; Spörri, M.

    2010-09-01

    Drought is one of the major threats to agricultural production worldwide. It occasionally affects agriculture in the Alpine region, although more intermittently than in other areas of Europe, notably the Mediterranean. Things may change, though, in the future if climate projections developed for the Alpine region in the context of the IPCC Fourth Assessment Report or the PRUDENCE project come true, with enhanced drought risk calling for adaptation. The focus of this contribution is on the characterization of drought occurrence in the Alpine region during 1864-2050. The analysis relies on historical weather records from Switzerland covering the period 1864-2010 and projections from the ENSEMBLES project for 2010-2050. Drought is quantified in terms of the standardized precipitation index (SPI), the modified moisture index (MMI) and the seasonal mean soil moisture availability. We show that the last decades were less prone to drought than the second half of the 19th century or the mid 20th century. We further examine these results using time series analysis and discuss regional differences. We then illustrate that according to the ENSEMBLES scenarios shifts in the drought regime until 2050 are likely to be less pronounced than previously thought, despite a marked warming and a moderate but significant increase in the length of dry spells. This suggests that further studies are needed to better understand changes in the hydrological cycle and their implications for drought risk.

  20. BAPA Database: Linking landslide occurrence with rainfall in Asturias (Spain)

    NASA Astrophysics Data System (ADS)

    Valenzuela, Pablo; José Domínguez-Cuesta, María; Jiménez-Sánchez, Montserrat

    2015-04-01

    Asturias is a region in northern Spain with a temperate and humid climate. In this region, slope instability processes are very common and often cause economic losses and, sometimes, human victims. To prevent the geological risk involved, it is of great interest to predict landslide spatial and temporal occurrence. Some previous investigations have shown the importance of rainfall as a trigger factor. Despite the high incidence of these phenomena in Asturias, there are no databases of recent and actual landslides. The BAPA Project (Base de Datos de Argayos del Principado de Asturias - Principality of Asturias Landslide Database) aims to create an inventory of slope instabilities which have occurred between 1980 and 2015. The final goal is to study in detail the relationship between rainfall and slope instabilities in Asturias, establishing precipitation thresholds and soil moisture conditions necessary to instability triggering. This work presents the database progress showing its structure divided into various fields that essentially contain information related to spatial, temporal, geomorphological and damage data.

  1. Occurrence and fate of organic contaminants during onsite wastewater treatment

    USGS Publications Warehouse

    Conn, K.E.; Barber, L.B.; Brown, G.K.; Siegrist, R.L.

    2006-01-01

    Onsite wastewater treatment systems serve approximately 25% of the U.S. population. However, little is known regarding the occurrence and fate of organic wastewater contaminants (OWCs), including endocrine disrupting compounds, during onsite treatment. A range of OWCs including surfactant metabolites, steroids, stimulants, metal-chelating agents, disinfectants, antimicrobial agents, and pharmaceutical compounds was quantified in wastewater from 30 onsite treatment systems in Summit and Jefferson Counties, CO. The onsite systems represent a range of residential and nonresidential sources. Eighty eight percent of the 24 target compounds were detected in one or more samples, and several compounds were detected in every wastewater sampled. The wastewater matrices were complex and showed unique differences between source types due to differences in water and consumer product use. Nonresidential sources generally had more OWCs at higher concentrations than residential sources. Additional aerobic biofilter-based treatment beyond the traditional anaerobic tank-based treatment enhanced removal for many OWCs. Removal mechanisms included volatilization, biotransformation, and sorption with efficiencies from 99% depending on treatment type and physicochemical properties of the compound. Even with high removal rates during confined unit onsite treatment, OWCs are discharged to soil dispersal units at loadings up to 20 mg/m2/d, emphasizing the importance of understanding removal mechanisms and efficiencies in onsite treatment systems that discharge to the soil and water environments. ?? 2006 American Chemical Society.

  2. Occurrence of Six Honeybee Viruses in Diseased Austrian Apiaries

    PubMed Central

    Berényi, Olga; Bakonyi, Tamás; Derakhshifar, Irmgard; Köglberger, Hemma; Nowotny, Norbert

    2006-01-01

    The occurrence, prevalence, and distribution patterns of acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Kashmir bee virus (KBV), and sacbrood virus (SBV) were investigated in 90 Austrian honeybee colonies suffering from symptoms of depopulation, sudden collapse, paralysis, or dark coloring by employing reverse transcription-PCR. Infestation with parasites was also recorded. The samples originated from all parts of Austria. The most prevalent virus was DWV, present in 91% of samples, followed by ABPV, SBV, and BQCV (68%, 49%, and 30%, respectively). CBPV was detected in 10% of colonies, while KBV was not present in any sample. In most samples, more than one virus was identified. The distribution pattern of ABPV, BQCV, CBPV, and SBV varied considerably in the different geographic regions investigated, while DWV was widespread in all Austrian federal states. In bees that showed dark coloring and disorientation, CBPV was always detected. Simultaneous infections of DWV and ABPV were most frequently observed in colonies suffering from weakness, depopulation, and sudden collapse. Bees obtained from apparently healthy colonies within the same apiaries showed a similar distribution pattern of viruses; however, the relative virus load was 10 to 126 times lower than in bees from diseased colonies. A limited number of bee samples from surrounding central European countries (Germany, Poland, Hungary, and Slovenia) were also tested for the presence of the above viruses. Variances were found in the distribution of BQCV and SBV. PMID:16597939

  3. [Occurrence of bacteria of the Yersinia genus in surface water].

    PubMed

    Krogulska, B; Maleszewska, J

    1992-01-01

    The aim of the study was determination of the frequency of occurrence of Yersinia genus bacteria in surface waters polluted to various degrees with bacteria of the coliform and of fecal coli. For detection of Yersinia rods the previously elaborated medium Endo MLCe and the membrane filter method were applied. Samples of 42 surface waters were examined, including 26 from rivers and 16 from lakes, ponds and clay-pits. On the basis of sanitary bacteriological analysis 16 surface waters were classified to class I purity, 10 to class II, the remaining ones to class III or beyond classification. Yersinia rods were detected in 15 water bodies that is 35.7% of the examined waters. A total of 27 Yersinia strains were identified with dominance of Y. intermedia (14 strains) and Y. enterocolitica (10 strains). Three strains represented by the species Yersinia frederiksenii. Most of the Y. enterocolitica strains belonged to biotype 1, the particular strains being represented by various serotypes. Hence their different origin may be concluded. The pathogenic serotypes 0:3 and 0:9 of Yersinia enterocolitica were not detected. PMID:1308748

  4. Occurrence of antibiotics in water from fish hatcheries

    USGS Publications Warehouse

    Thurman, Earl M.; Dietze, Julie E.; Scribner, Elisabeth A.

    2002-01-01

    The recent discovery of pharmaceuticals in streams across the United States (Kolpin and others, 2002) has raised the visibility and need for monitoring of antibiotics in the environment. Possible sources of antibiotics and other pharmaceuticals in streams may include fish hatcheries. This fact sheet presents the results from a preliminary study of fish hatcheries across the United States for the occurrence and concentration of antibiotics present in fish hatchery water. The study examines both sufonamides and tetracyclines. Sulfonamides are synthetic compounds, and tetracyclines are naturally occurring compounds. The use of antibiotics added to specially formulated feed is a common practice in fish hatcheries to treat and prevent bacterial infections in large fish populations. U.S. Food and Drug Administration (FDA) approved antibiotics are oxytetracycline-HCI, sulfamerazine, and a combination drug containing ormetoprim and sulfadiamethoxine (U.S. Food and Drug Administration, 2003). During January 2001?June 2002, the U.S. Geological Survey (USGS) Organic Geochemistry Research Laboratory (OGRL), Lawrence, Kansas, cooperatively collected water samples from 13 fish hatcheries across the United States (fig. 1) with the assistance of hatchery operators. A method for the analysis of antibiotics was developed and used to identify and quantify these compounds in fish hatchery water (Lindsey and others, 2001). This study was completed to determine if trace levels of antibiotics [approximately 1 microgram per liter (?g/L) or 1 part per billion or greater occurred] in which water associated with fish hatcheries, which are a potential source of these compounds in surface water.

  5. Occurrence and seasonal transmission of hematozoa in wild turkeys.

    PubMed

    Stacey, L M; Couvillion, C E; Siefker, C; Hurst, G A

    1990-10-01

    The occurrence and seasonal patterns of transmission of the blood protozoa of wild turkeys (Meleagris gallopavo silvestris) were studied at Tallahala Wildlife Management Area (TWMA) (Jasper County, Mississippi, USA). Blood smears obtained from wild turkeys in winter, spring and summer, and from sentinel domestic turkeys throughout the year were examined for Haemoproteus meleagridis and Leucocytozoon smithi. Whole blood from wild turkeys captured in summer was subinoculated into malaria-free domestic turkey poults and recipient birds were examined for Plasmodium spp. The prevalence of H. meleagridis and L. smithi were not different (P greater than 0.05) between adults and juveniles or between male and female turkeys in any season. Leucocytozoon smithi was not detected in poults in summer or in juveniles examined in winter. Sentinel studies and information from wild birds revealed that transmission of H. meleagridis and L. smithi did not overlap. Haemoproteus meleagridis was transmitted from May through November, while L. smithi was transmitted only from January through April. The onset of transmission of H. meleagridis coincided with peak hatching (mid-May) and brood-rearing (May-November) of turkey poults. Plasmodium spp. were not found in turkeys from TWMA (n = 27) nor in birds from three widely separated counties (n = 28) in Mississippi.

  6. Occurrence and Biodegradation of Nonylphenol in the Environment

    PubMed Central

    Mao, Zhen; Zheng, Xiao-Fei; Zhang, Yan-Qiu; Tao, Xiu-Xiang; Li, Yan; Wang, Wei

    2012-01-01

    Nonylphenol (NP) is an ultimate degradation product of nonylphenol polyethoxylates (NPE) that is primarily used in cleaning and industrial processes. Its widespread use has led to the wide existence of NP in various environmental matrices, such as water, sediment, air and soil. NP can be decreased by biodegradation through the action of microorganisms under aerobic or anaerobic conditions. Half-lives of biodegradation ranged from a few days to almost one hundred days. The degradation rate for NP was influenced by temperature, pH and additions of yeast extracts, surfactants, aluminum sulfate, acetate, pyruvate, lactate, manganese dioxide, ferric chloride, sodium chloride, hydrogen peroxide, heavy metals, and phthalic acid esters. Although NP is present at low concentrations in the environment, as an endocrine disruptor the risks of long-term exposure to low concentrations remain largely unknown. This paper reviews the occurrence of NP in the environment and its aerobic and anaerobic biodegradation in natural environments and sewage treatment plants, which is essential for assessing the potential risk associated with low level exposure to NP and other endocrine disruptors. PMID:22312266

  7. Occurrence of perfluoroalkyl acids in environmental waters in Vietnam.

    PubMed

    Duong, Hanh Thi; Kadokami, Kiwao; Shirasaka, Hanako; Hidaka, Rento; Chau, Hong Thi Cam; Kong, Lingxiao; Nguyen, Trung Quang; Nguyen, Thao Thanh

    2015-03-01

    This is the first nationwide study of perfluoroalkyl acids (PFAAs) in environmental waters in Vietnam. Twenty-eight river water and 22 groundwater samples collected in four major cities and 14 river water samples from the Red River were screened to investigate the occurrence and sources of 16 PFAAs. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were the most prevalent of 11 detected PFAAs with maximum concentrations in urban river water of 5.3, 18 and 0.93ngL(-1), respectively, and in groundwater of 8.2, 4.5 and 0.45ngL(-1), respectively. PFAAs in the Red River water were detected at low levels. PFAA concentrations in river water were higher in the rainy season than in the dry season, possibly due to storm water runoff, a common phenomenon in Southeast Asian countries. The highest concentrations of PFAAs in river water were observed in samples from highly populated and industrialized areas, perhaps sourced from sewage. The PFAA concentrations observed were similar to those in other Southeast Asian countries, but lower than in developed nations. From the composition profiles of PFAAs, industrial products containing PFAAs imported from China and Japan might be one of the major sources of PFAAs in the Vietnamese aquatic environment. According to the health-based values and advisory issued by the United States Environmental Protection Agency (USEPA), the concentrations of detected PFAAs in this study do not pose an immediate health risk to humans and aquatic organisms.

  8. Common occurrence of antibacterial agents in human intestinal microbiota.

    PubMed

    Drissi, Fatima; Buffet, Sylvain; Raoult, Didier; Merhej, Vicky

    2015-01-01

    Laboratory experiments have revealed many active mechanisms by which bacteria can inhibit the growth of other organisms. Bacteriocins are a diverse group of natural ribosomally synthesized antimicrobial peptides produced by a wide range of bacteria and which seem to play an important role in mediating competition within bacterial communities. In this study, we have identified and established the structural classification of putative bacteriocins encoded by 317 microbial genomes in the human intestine. On the basis of homologies to available bacteriocin sequences, mainly from lactic acid bacteria, we report the widespread occurrence of bacteriocins across the gut microbiota: 175 bacteriocins were found to be encoded in Firmicutes, 79 in Proteobacteria, 34 in Bacteroidetes, and 25 in Actinobacteria. Bacteriocins from gut bacteria displayed wide differences among phyla with regard to class distribution, net positive charge, hydrophobicity and secondary structure, but the α-helix was the most abundant structure. The peptide structures and physiochemical properties of bacteriocins produced by the most abundant bacteria in the gut, the Firmicutes and the Bacteroidetes, seem to ensure low antibiotic activity and participate in permanent intestinal host defense against the proliferation of harmful bacteria. Meanwhile, the potentially harmful bacteria, including the Proteobacteria, displayed highly effective bacteriocins, probably supporting the virulent character of diseases. These findings highlight the eventual role played by bacteriocins in gut microbial competition and their potential place in antibiotic therapy.

  9. Recent increases in extreme temperature occurrence over land

    NASA Astrophysics Data System (ADS)

    Weaver, Scott J.; Kumar, Arun; Chen, Mingyue

    2014-07-01

    Recently observed global and U.S. temperature increases are probed from the perspective of several hundred climate realizations afforded by the availability of reforecast climate model runs from the NCEP Climate Forecast System Version 2. The large number of seasonal realizations with the observed time-varying CO2 affords a unique opportunity to explore the role of greenhouse gas changes on 3 month seasonal mean temperature increases, and specifically, whether they are the result of a shift in the mean temperature distribution or an increase in its variability. It is found that significant positive shifts in the temperature probability density function (PDF) occur primarily as the result of the time-varying CO2 included in the historical model runs, although a contribution from natural climate variability modes cannot be categorically excluded. The temperature PDF comparison further indicates that the increasing global and U.S. temperatures over the last 30 years are predominantly the result of shifts in the mean temperature distribution and not increasing temperature variability. As such, the likelihood of increases in the occurrence of warm temperature extremes will likely continue to increase worldwide, leading to significant impacts on many socioeconomic sectors such as agriculture and public health.

  10. Estimating the empirical probability of submarine landslide occurrence

    USGS Publications Warehouse

    Geist, Eric L.; Parsons, Thomas E.; Mosher, David C.; Shipp, Craig; Moscardelli, Lorena; Chaytor, Jason D.; Baxter, Christopher D. P.; Lee, Homa J.; Urgeles, Roger

    2010-01-01

    The empirical probability for the occurrence of submarine landslides at a given location can be estimated from age dates of past landslides. In this study, tools developed to estimate earthquake probability from paleoseismic horizons are adapted to estimate submarine landslide probability. In both types of estimates, one has to account for the uncertainty associated with age-dating individual events as well as the open time intervals before and after the observed sequence of landslides. For observed sequences of submarine landslides, we typically only have the age date of the youngest event and possibly of a seismic horizon that lies below the oldest event in a landslide sequence. We use an empirical Bayes analysis based on the Poisson-Gamma conjugate prior model specifically applied to the landslide probability problem. This model assumes that landslide events as imaged in geophysical data are independent and occur in time according to a Poisson distribution characterized by a rate parameter λ. With this method, we are able to estimate the most likely value of λ and, importantly, the range of uncertainty in this estimate. Examples considered include landslide sequences observed in the Santa Barbara Channel, California, and in Port Valdez, Alaska. We confirm that given the uncertainties of age dating that landslide complexes can be treated as single events by performing statistical test of age dates representing the main failure episode of the Holocene Storegga landslide complex.

  11. Predicting carnivore occurrence with noninvasive surveys and occupancy modeling

    USGS Publications Warehouse

    Long, Robert A.; Donovan, Therese M.; MacKay, Paula; Zielinski, William J.; Buzas, Jeffrey S.

    2011-01-01

    Terrestrial carnivores typically have large home ranges and exist at low population densities, thus presenting challenges to wildlife researchers. We employed multiple, noninvasive survey methods—scat detection dogs, remote cameras, and hair snares—to collect detection–nondetection data for elusive American black bears (Ursus americanus), fishers (Martes pennanti), and bobcats (Lynx rufus) throughout the rugged Vermont landscape. We analyzed these data using occupancy modeling that explicitly incorporated detectability as well as habitat and landscape variables. For black bears, percentage of forested land within 5 km of survey sites was an important positive predictor of occupancy, and percentage of human developed land within 5 km was a negative predictor. Although the relationship was less clear for bobcats, occupancy appeared positively related to the percentage of both mixed forest and forested wetland habitat within 1 km of survey sites. The relationship between specific covariates and fisher occupancy was unclear, with no specific habitat or landscape variables directly related to occupancy. For all species, we used model averaging to predict occurrence across the study area. Receiver operating characteristic (ROC) analyses of our black bear and fisher models suggested that occupancy modeling efforts with data from noninvasive surveys could be useful for carnivore conservation and management, as they provide insights into habitat use at the regional and landscape scale without requiring capture or direct observation of study species.

  12. Predicting the Occurrence of Cosmetic Defects in Automotive Skin Panels

    SciTech Connect

    Hazra, S.; Williams, D.; Roy, R.; Aylmore, R.; Allen, M.; Hollingdale, D.

    2011-05-04

    The appearance of defects such as 'hollows' and 'shock lines' can affect the perceived quality and attractiveness of automotive skin panels. These defects are the result of the stamping process and appear as small, localized deviations from the intended styling of the panels. Despite their size, they become visually apparent after the application of paint and the perceived quality of a panel may become unacceptable. Considerable time is then dedicated to minimizing their occurrence through tool modifications. This paper will investigate the use of the wavelet transform as a tool to analyze physically measured panels. The transform has two key aspects. The first is its ability to distinguish small scale local defects from large scale styling curvature. The second is its ability to characterize the shape of a defect in terms of its wavelength and a 'correlation value'. The two features of the transform enable it to be used as a tool for locating and predicting the severity of defects. The paper will describe the transform and illustrate its application on test cases.

  13. Occurrence and distribution of gas vesicle genes among cyanobacteria.

    PubMed Central

    Damerval, T; Castets, A M; Guglielmi, G; Houmard, J; Tandeau de Marsac, N

    1989-01-01

    Gas vesicles (GV) are specialized cell inclusions providing many aquatic procaryotes with buoyancy. In the cyanobacterium Calothrix sp. strain PCC 7601, at least four genes are involved in GV formation. One of those, gvpA1, encodes the major structural GV protein (70 amino acids) and belongs to a multigene family (gvpA1, gvpA2, gvpD). The fourth gene, gvpC, encodes a 162-amino-acid protein, the function of which is still unclear. We used the Calothrix gvpA1 and gvpC genes as probes to perform Southern hybridization experiments with DNA extracted from various cyanobacterial strains. The gvpA gene was found in all the strains that synthesize GV, indicating that its product is an obligatory component of GV. Furthermore, it was found to occur as multiple copies in most of the strains tested. The gvpC gene was only detected in some strains able to synthesize a large amount of GV within a short period. This suggests that the gvpC gene product is a dispensable protein for GV formation and is involved in the efficiency of the assembly process. Based on the occurrence of the gvp genes and on DNA-DNA hybridization patterns, genus assignments are discussed. Images PMID:2493445

  14. Recent Increases in Extreme Temperature Occurrence over Land

    NASA Astrophysics Data System (ADS)

    Weaver, S. J.; Kumar, A.; Chen, M.

    2014-12-01

    Recently observed global and U.S. temperature increases are probed from the perspective of several hundred climate realizations afforded by the availability of reforecast climate model runs from the NCEP Climate Forecast System Version 2 (CFSv2). The large number of seasonal realizations with the observed time varying CO2 affords a unique opportunity to explore the role of greenhouse gas changes on 3-month seasonal mean temperature increases, and specifically, whether they are the result of a shift in the mean temperature distribution or an increase in its variability. It is found that significant positive shifts in the temperature Probability Density Function (PDF) occurs primarily as the result of the time varying CO2 included in the historical model runs, although a contribution from natural climate variability modes cannot be categorically excluded. The temperature PDF comparison further indicates that the increasing global and U.S. temperatures over the last 30 years are predominantly the result of shifts in the mean temperature distribution and not increasing temperature variability. As such, the likelihood of increases in the occurrence of warm temperature extremes will likely continue to increase worldwide, leading to significant impacts on many socioeconomic sectors such as agriculture and public health.

  15. Predicting the Occurrence of Cosmetic Defects in Automotive Skin Panels

    NASA Astrophysics Data System (ADS)

    Hazra, S.; Williams, D.; Roy, R.; Aylmore, R.; Allen, M.; Hollingdale, D.

    2011-05-01

    The appearance of defects such as `hollows' and `shock lines' can affect the perceived quality and attractiveness of automotive skin panels. These defects are the result of the stamping process and appear as small, localized deviations from the intended styling of the panels. Despite their size, they become visually apparent after the application of paint and the perceived quality of a panel may become unacceptable. Considerable time is then dedicated to minimizing their occurrence through tool modifications. This paper will investigate the use of the wavelet transform as a tool to analyze physically measured panels. The transform has two key aspects. The first is its ability to distinguish small scale local defects from large scale styling curvature. The second is its ability to characterize the shape of a defect in terms of its wavelength and a `correlation value'. The two features of the transform enable it to be used as a tool for locating and predicting the severity of defects. The paper will describe the transform and illustrate its application on test cases.

  16. Occurrence and spatial distribution of microplastics in sediments from Norderney.

    PubMed

    Dekiff, Jens H; Remy, Dominique; Klasmeier, Jörg; Fries, Elke

    2014-03-01

    The spatial distribution of small potential microplastics (SPM) (<1 mm) in beach sediments was studied on a 500 m stretch of the North Sea island of Norderney. Their correlation with visible plastic debris (VPD) (>1 mm) was also examined. Small microparticles were extracted from 36 one kg sediment samples and analysed by visual microscopic inspection and partly by thermal desorption pyrolysis gas chromatography/mass spectrometry. The smallest particle size that could be analysed with this method was estimated to be 100 μm. The mean number of SPM at the three sampling sites (n = 12) was 1.7, 1.3 and 2.3 particles per kg dry sediment, respectively. SPM were identified as polypropylene, polyethylene, polyethylene terephthalate, polyvinylchloride, polystyrene and polyamide. The organic plastic additives found were benzophenone, 1,2-benzenedicarboxylic acid, dimethyl phthalate, diethylhexyl phthalate, dibutyl phthalate, diethyl phthalate, phenol and 2,4-di-tert-butylphenol. Particles were distributed rather homogenously and the occurrence of SPM did not correlate with that of VPD.

  17. The occurrence of tricin and its derivatives in plants

    DOE PAGESBeta

    Li, Mi; Pu, Yunqiao; Yoo, Chang Geun; Ragauskas, Arthur J.

    2016-02-02

    Our understanding of the structure and biosynthetic pathway of lignin, a phenylpropanoid heteropolymer, continues to evolve, especially with the discovery of new lignin monomers/structural moieties such as monolignol acetate, hydroxycinnamyl aldehyde/alcohol, and p-hydroxybenzoate in the past decades. Recently, tricin has been reported as a component incorporated into monocot lignin. As a flavonoid compound widely distributed in herbaceous plants, tricin has been extensively studied due to its biological significance in plant growth as well as its potential for pharmaceutical importance. Tricin is biosynthesized as a constituent of plant secondary metabolites through a combination of phenylpropanoid and polyketide pathways. Tricin occurs inmore » plants in either free or conjugated forms such as tricin-glycosides, tricin-lignans, and tricin-lignan-glycosides.The emergence of tricin covalently incorporated with lignin biopolymer implies the possible association of lignification and tricin biosynthesis. This review summarizes the occurrence of tricin and its derivatives in plants. Additionally, synthesis, potential application, and characterization of tricin are discussed.« less

  18. Azole fungicides: occurrence and fate in wastewater and surface waters.

    PubMed

    Kahle, Maren; Buerge, Ignaz J; Hauser, Andrea; Müller, Markus D; Poiger, Thomas

    2008-10-01

    The mode of action of azole compounds implies a potential to affect endocrine systems of different organisms and is reason for environmental concern. The occurrence and fate of nine agricultural azole fungicides, some of them also used as biocides, and four azole pharmaceuticals were studied in wastewater treatment plants (WWTPs) and lakes in Switzerland. Two pharmaceuticals (fluconazole, clotrimazole, 10-110 ng L(-1)) and two biocides (propiconazole, tebuconazole, 1-30 ng L(-1)) were consistently observed in WWTP influents. Loads determined in untreated and treated wastewater indicated thatfluconazole, propiconazole, and tebuconazole were largely unaffected by wastewater treatment, but clotrimazole was effectively eliminated (> 80%). Incubation studies with activated sludge showed no degradation for fluconazole and clotrimazole within 24 h, but strong sorption of clotrimazole to activated sludge. Slow degradation and some sorption were observed for tebuconazole and propiconazole (degradation half-lives, 2-3 d). In lakes, fluconazole, propiconazole, and tebuconazole were detected at low nanogram-per-liter levels. Concentrations of the pharmaceutical fluconazole correlated with the expected contamination by domestic wastewater, but not those of the biocides. Per capita loads of propiconazole and tebuconazole in lakes suggested additional inputs; for example, from agricultural use or urban runoff rainwater.

  19. Tibiofemoral angle and its relation to ankle sprain occurrence.

    PubMed

    Pefanis, Nikolaos; Karagounis, Panagiotis; Tsiganos, Georgios; Armenis, Elias; Baltopoulos, Panagiotis

    2009-12-01

    The lack of a normal joint orientation generates translational or shear forces across the joint. These forces can put abnormally high strain on the cartilage and the surrounding capsuloligamentous tissues. Ankle joint structure can affect or be affected by bony malformations of the surrounding areas, including the knee and hip. The aim of the current study is to examine the possible relationship between the tibiofemoral (TFA) angle and other factors (anthropometric characteristics, medical history, and age) on the occurrence of ankle sprains because its value provides useful information for the anatomical alignment of the lower extremity. The study sample consisted of 45 high-level athletes, evenly distributed among 3 sports (basketball, soccer, and volleyball). TFA measurements were made on radiographs. The study lasted 2 years. A logistic regression was used to determine the importance of each factor on the probability in question. A significance level of P = .1 was used. The factors contributing more to an ankle sprain were a previous injury of the same type followed by body mass index (BMI) and age. On the contrary, TFA was proven to be statistically nonsignificant. When the BMI variable was substituted with body inertia propensity, a derived variable, the TFA remained statistically nonsignificant. TFA magnitude does not seem to be a determinant factor that could increase the probability of spraining an ankle.

  20. Occurrence of phlogopite in the Finero Mafic layered complex

    NASA Astrophysics Data System (ADS)

    Giovanardi, Tommaso; Mazzucchelli, Maurizio; Zanetti, Alberto; Langone, Antonio; Tiepolo, Massimo; Cipriani, Anna

    2014-12-01

    Phlogopite-bearing lithologies are the main constituent of the Phlogopite-Peridotite unit of the Finero sequence and the result of pervasive migration of metasomatizing melts/fluids. Conversely, the presence of phlogopite within the associated Finero Mafic Complex, a mafic-ultramafic pluton intruded into the metamorphic basement of the Adria plate, is mentioned in literature as rare. Recent detailed fieldwork has evidenced the presence of two distinct phlogopite-rich ultramafic lithologies within the Amphibole-Peridotite unit of the Finero Mafic Complex, where phlogopite is always associated with amphibole. Field and petrographic features of these occurrences, as well as major- and trace-element mineral chemistry, are here presented to i) place constraints on the nature of the parent melt from which they have been generated and ii) to address their relationship with the other lithologies of the Finero Complex. We find that these rocks were formed by late melt migrations along shear zones under high-T conditions. The geochemical affinity of these lithologies is different to the tholeiitic-transitional affinity reported in literature for the Finero Mafic Complex. The enrichment in LREE, Th, U and Sr of the associated amphibole possibly suggests that these phlogopite-bearing lithologies are genetically related to the metasomatic events that have affected the Finero mantle massif.

  1. A global compendium of human Crimean-Congo haemorrhagic fever virus occurrence.

    PubMed

    Messina, Jane P; Pigott, David M; Duda, Kirsten A; Brownstein, John S; Myers, Monica F; George, Dylan B; Hay, Simon I

    2015-01-01

    In order to map global disease risk, a geographic database of human Crimean-Congo haemorrhagic fever virus (CCHFV) occurrence was produced by surveying peer-reviewed literature and case reports, as well as informal online sources. Here we present this database, comprising occurrence data linked to geographic point or polygon locations dating from 1953 to 2013. We fully describe all data collection, geo-positioning, database management and quality-control procedures. This is the most comprehensive database of confirmed CCHF occurrence in humans to-date, containing 1,721 geo-positioned occurrences in total.

  2. ON THE OCCURRENCE RATE OF HOT JUPITERS IN DIFFERENT STELLAR ENVIRONMENTS

    SciTech Connect

    Wang, Ji; Fischer, Debra A.; Horch, Elliott P.; Huang, Xu

    2015-02-01

    Many hot Jupiters (HJs) are detected by the Doppler and transit techniques. From surveys using these two techniques, however, the measured HJ occurrence rates differ by a factor of two or more. Using the California Planet Survey sample and the Kepler sample, we investigate the causes for this difference in the HJ occurrence rate. First, we find that 12.8% ± 0.24% of HJs are misidentified in the Kepler mission because of photometric dilution and subgiant contamination. Second, we explore the differences between the Doppler sample and the Kepler sample that can account for the different HJ occurrence rate. Third, we discuss how to measure the fundamental HJ occurrence rates by synthesizing the results from the Doppler and Kepler surveys. The fundamental HJ occurrence rates are measures of the HJ occurrence rate as a function of stellar multiplicity and evolutionary stage, e.g., the HJ occurrence rate for single and multiple stars or for main-sequence and subgiant stars. While we find qualitative evidence that HJs occur less frequently in subgiants and multiple stellar systems, we conclude that our current knowledge of stellar properties and the stellar multiplicity rate is too limited for us to reach any quantitative result for the fundamental HJ occurrence rates. This concern extends to η{sub Earth}, the occurrence rate of Earth-like planets.

  3. A global compendium of human Crimean-Congo haemorrhagic fever virus occurrence.

    PubMed

    Messina, Jane P; Pigott, David M; Duda, Kirsten A; Brownstein, John S; Myers, Monica F; George, Dylan B; Hay, Simon I

    2015-01-01

    In order to map global disease risk, a geographic database of human Crimean-Congo haemorrhagic fever virus (CCHFV) occurrence was produced by surveying peer-reviewed literature and case reports, as well as informal online sources. Here we present this database, comprising occurrence data linked to geographic point or polygon locations dating from 1953 to 2013. We fully describe all data collection, geo-positioning, database management and quality-control procedures. This is the most comprehensive database of confirmed CCHF occurrence in humans to-date, containing 1,721 geo-positioned occurrences in total. PMID:25977820

  4. Features of the F3 layer occurrence over the equatorial location of Trivandrum

    NASA Astrophysics Data System (ADS)

    Sreeja, V.; Ravindran, S.; Pant, T. K.

    2010-09-01

    The general features of the F3 layer occurrence over the magnetic equatorial location of Trivandrum (8.5° N; 77° E; dip lat ~0.5° N) in India during the period from 1996-2005 are presented using the ionosonde observations. The study brings out that the F3 layer occurrence over Trivandrum is weak and rare compared to the other equatorial locations. The F3 layer occurrence is relatively more pronounced during the magnetically active conditions, thus indicating the dependence of the layer formation over Trivandrum on magnetic activity. It is also observed that the percentage occurrence of the F3 layer decreases with increasing solar activity.

  5. Occurrence of Equatorial F Region Irregularities: Evidence for Tropospheric Seeding

    NASA Technical Reports Server (NTRS)

    McClure, J. P.; Singh, S.; Bamgboye, D. K.; Johnson, F. S.; Kil, Hyosub

    1998-01-01

    We present a new gap-free version of the seasonal and longitudinal 0 (s/l) variations of P(sub EFI), the equatorial F region irregularity (EFI) occurrence probability, based on data from the AE-E spacecraft. The agreement of this and three earlier partial P(sub EFI) patterns verifies all four. We reinterpret another earlier gap-ridden pattern, that of D(bar)(sub RSF), a topside ionogram index of average darkening by range spread F. We compare it with P(sub EFI) and, using ionosonde radio science considerations, we conclude that D(bar)(sub RSF) = P(sub EFI) times a factor depending on the average number of topside plasma bubbles visible to the ionosonde. The s/l variations of D(baar)(sub RSF) thus imply s/l variations in the average spacing of bubbles, whose seeds have an occurrence probability pattern P(sub seed). For discussion we assume P(sub EFI) = P(sub inst)P(sub seed) is the pattern of F region instability. The P(sub EFI) pattern, which is by definition independent of seed and/or bubble spacing, is far too complex to be explained by the dominant paradigm, that of changes in P(sub inst) by simple changes in the F region altitude and/or north-south asymmetry. We examine evidence behind this dominance, and find it unconvincing. Both the asymmetry and sunset-node/altitude hypotheses of 1984 and 1985, respectively, seem to be partly based on misunderstood data, and their features appear displaced in time and space from those of our repeatable P(sub EFI) pattern. In contrast, if P(sub seed) variations influence the P(sub EFI) pattern and depend on thermospheric gravity waves from tropospheric convection near the dip equator, then the seasonal maxima (minima) Of P(sub EFI) could be explained, since they all occur above relatively warm (cold) surface features, where convection is maximal (minimal). Also, the hypothesis of the dominance of the P(sub seed) term could explain an unusual December/January P(sub EFI) maximum in the deep, wide, normal Pacific minimum in the

  6. Tamarugite from Diana Cave (SW Romania) -first true karst occurrence

    NASA Astrophysics Data System (ADS)

    Pušcaš, C. M.; Onac, B. P.; Effenberger, H. S.; Povarǎ, I.

    2012-04-01

    Diana Cave is located within the town limits of Baile Herculane (SW Romania) and develops as a 14 m long, westward oriented, unique passage guided by the Diana fault [1]. At the far end of the cave, the thermo-mineral Diana Spring wells forth. In the early 1970s a mine gallery that intersected the cave was created to drain the water into a pumping station and the original cave passage was somewhat altered and reinforced with concrete. Today the concrete and the silty limestone cave walls are heavily corroded by H2SO4 outgassing from the hot water (ca. 50°C) and display abundant gypsum crusts, soggy aggregates of native S, and a variety of more exotic sulfates. Among them, a mineral that has been previously identified in caves only in connection to volcanic activity, either as thermal springs or fumaroles [2]: tamarugite [NaAl(SO4)26H2O]. It was [3] that first mentioned the occurrence of this Na and Al sulfate in Diana Cave, our research aiming to give a detailed description of this mineral, its paragenesis, and mechanisms of precipitation. Recently, tamarugite has also been identified in a sulfuric acid cave from Greece [4]. Along with powder X-ray diffractions coupled with Rietveld refinement, scanning electron microscope, and electron probe micro-analysis, δ18O and δ34S compositions of the sulfate mineral as well as precipitates from the water were analyzed to identify and better constrain the genesis of this rare sulfate. Regrettably, the crystal size of our specimens is inappropriate for identification by means of single crystal X-ray diffraction. Physical and chemical parameters of Diana Spring were as well measured on several occasions. Geochemical analysis suggests that the minute, white tamarugite flakes precipitated in Diana Cave as a result of the interactions between the thermo-mineral water or water vapor and the original limestone bedrock and concrete that blankets the mine gallery. [1] Povara, I., Diaconu, G., Goran, C. (1972). Observations pr

  7. Modeling of the occurrence of hydrogen sulfide in coal seams

    SciTech Connect

    Gillies, A.D.S.; Kizil, M.S.; Wu, H.W.; Harvey, T.J.M.

    1999-07-01

    Hydrogen Sulfide (H{sub 2}S) has been encountered within a number of Bowen Basin collieries, Central Queensland, Australia. High concentration occurrence during mining of a longwall panel raises a number of potential problems, which demand greater understanding to allow efficient mining while maintaining safe and healthy environmental conditions. Longwall panels at Mine A and Mine B have recently mined through H{sub 2}S zones. The high H{sub 2}S zone mined through at Mine A was wide and covering the whole length of the face comparing to the narrow H{sub 2}S zone which was cutting the panel at 45{degree} at Mine B. Longwall panels had been sampled for H{sub 2}S in pre-mining phases with vertical and inseam exploration boreholes and rib sampling of gateroad development headings. During mining face coal samples were collected in an intensive program and tested in a drum tumbler to determine an indicated seam concentration level through contouring that could be used to calculate the concentrations of H{sub 2}S liberated to the atmosphere. Data were analyzed to determine a geostatistical method, which would best represent the indicated seam concentration level from the given data and the block dimension of the data set. This study discusses the different sampling methods used, selection of the most suitable geostatistical method and the impact of grid size on results of data analysis. Some general observations are made correlating indicated seam H{sub 2}S concentrations from production face sampling with both predictions made from exploration and liberation rates during mining of the longwall panel.

  8. Occurrence of mitral valve insufficiency in clinically healthy Beagle dogs.

    PubMed

    Vörös, Károly; Szilvási, Viktória; Manczur, Ferenc; Máthé, Ákos; Reiczigel, Jenő; Nolte, Ingo; Hungerbühler, Stephan

    2015-12-01

    Chronic degenerative valve disease (CDVD) is the most common cardiac disease in dogs, usually resulting in mitral valve insufficiency (MVI). The goal of this study was to investigate the occurrence of MVI in clinically healthy Beagle populations. A total of 79 adult healthy Beagles (41 females and 38 males; age: 5.6 ± 2.7 years, range 1.4 to 11.7 years) were examined. The diagnosis of MVI was based on the detection of a systolic murmur heard above the mitral valve, and was confirmed by colour flow Doppler (CFD) echocardiography. Systolic mitral valve murmurs were detected in 20/79 dogs (25.3%), of them 11 males and 9 females with no statistically significant gender difference (P = 0.6059). The strength of the murmur on the semi-quantitative 0/6 scale yielded intensity grade 1/6 in 10 dogs, grade 2/6 in 4 dogs, and grade 3/6 in 6 dogs. Mild to moderate MVI was detected by CFD in all these 20 dogs with systolic murmurs. Of them, 17 dogs had mild and 3 demonstrated moderate MVI, showing 10-30% and 30-50% regurgitant jets compared to the size of the left atrium, respectively. The age of dogs with MVI was 7.1 ± 2.3 years, which was significantly different from that of dogs without MVI (5.1 ± 2.7 years, P = 0.0029). No significant differences in body weight (P = 0.1724) were found between dogs with MVI (13.8 ± 2.8 kg) and those without MVI (12.8 ± 3.0 kg). Mitral valve disease causing MVI is relatively common in Beagle dogs, just like in other small breed dogs reported in the literature. PMID:26599093

  9. Assessing historical rate changes in global tsunami occurrence

    NASA Astrophysics Data System (ADS)

    Geist, Eric L.; Parsons, Tom

    2011-10-01

    The global catalogue of tsunami events is examined to determine if transient variations in tsunami rates are consistent with a Poisson process commonly assumed for tsunami hazard assessments. The primary data analyzed are tsunamis with maximum sizes >1 m. The record of these tsunamis appears to be complete since approximately 1890. A secondary data set of tsunamis >0.1 m is also analyzed that appears to be complete since approximately 1960. Various kernel density estimates used to determine the rate distribution with time indicate a prominent rate change in global tsunamis during the mid-1990s. Less prominent rate changes occur in the early- and mid-20th century. To determine whether these rate fluctuations are anomalous, the distribution of annual event numbers for the tsunami catalogue is compared to Poisson and negative binomial distributions, the latter of which includes the effects of temporal clustering. Compared to a Poisson distribution, the negative binomial distribution model provides a consistent fit to tsunami event numbers for the >1 m data set, but the Poisson null hypothesis cannot be falsified for the shorter duration >0.1 m data set. Temporal clustering of tsunami sources is also indicated by the distribution of interevent times for both data sets. Tsunami event clusters consist only of two to four events, in contrast to protracted sequences of earthquakes that make up foreshock-main shock-aftershock sequences. From past studies of seismicity, it is likely that there is a physical triggering mechanism responsible for events within the tsunami source 'mini-clusters'. In conclusion, prominent transient rate increases in the occurrence of global tsunamis appear to be caused by temporal grouping of geographically distinct mini-clusters, in addition to the random preferential location of global M >7 earthquakes along offshore fault zones.

  10. Widespread Occurrence of Bd in French Guiana, South America

    PubMed Central

    Courtois, Elodie A.; Gaucher, Philippe; Chave, Jérôme; Schmeller, Dirk S.

    2015-01-01

    The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) is a purported agent of decline and extinction of many amphibian populations worldwide. Its occurrence remains poorly documented in many tropical regions, including the Guiana Shield, despite the area’s high amphibian diversity. We conducted a comprehensive assessment of Bd in French Guiana in order to (1) determine its geographical distribution, (2) test variation of Bd prevalence among species in French Guiana and compare it to earlier reported values in other South American anuran species (http://www.bd-maps.net; 123 species from 15 genera) to define sentinel species for future work, (3) track changes in prevalence through time and (4) determine if Bd presence had a negative effect on one selected species. We tested the presence of Bd in 14 species at 11 sites for a total of 1053 samples (306 in 2009 and 747 in 2012). At least one Bd-positive individual was found at eight out of 11 sites, suggesting a wide distribution of Bd in French Guiana. The pathogen was not uniformly distributed among the studied amphibian hosts, with Dendrobatidae species displaying the highest prevalence (12.4%) as compared to Bufonidae (2.6 %) and Hylidae (1.5%). In contrast to earlier reported values, we found highest prevalence for three Dendrobatidae species and two of them displayed an increase in Bd prevalence from 2009 to 2012. Those three species might be the sentinel species of choice for French Guiana. For Dendrobates tinctorius, of key conservation value in the Guiana Shield, smaller female individuals were more likely to be infected, suggesting either that frogs can outgrow their chytrid infections or that the disease induces developmental stress limiting growth. Generally, our study supports the idea that Bd is more widespread than previously thought and occurs at remote places in the lowland forest of the Guiana shield. PMID:25902035

  11. Occurrence of arsenic contamination in Canada: sources, behavior and distribution.

    PubMed

    Wang, Suiling; Mulligan, Catherine N

    2006-08-01

    Recently there has been increasing anxieties concerning arsenic related problems. Occurrence of arsenic contamination has been reported worldwide. In Canada, the main natural arsenic sources are weathering and erosion of arsenic-containing rocks and soil, while tailings from historic and recent gold mine operations and wood preservative facilities are the principal anthropogenic sources. Across Canada, the 24-h average concentration of arsenic in the atmosphere is generally less than 0.3 microg/m3. Arsenic concentrations in natural uncontaminated soil and sediments range from 4 to 150 mg/kg. In uncontaminated surface and ground waters, the arsenic concentration ranges from 0.001 to 0.005 mg/L. As a result of anthropogenic inputs, elevated arsenic levels, above ten to thousand times the Interim Maximum Acceptable Concentration (IMAC), have been reported in air, soil and sediment, surface water and groundwater, and biota in several regions. Most arsenic is of toxic inorganic forms. It is critical to recognize that such contamination imposes serious harmful effects on various aquatic and terrestrial organisms and human health ultimately. Serious incidences of acute and chronic arsenic poisonings have been revealed. Through examination of the available literature, screening and selecting existing data, this paper provides an analysis of the currently available information on recognized problem areas, and an overview of current knowledge of the principal hydrogeochemical processes of arsenic transportation and transformation. However, a more detailed understanding of local sources of arsenic and mechanisms of arsenic release is required. More extensive studies will be required for building practical guidance on avoiding and reducing arsenic contamination. Bioremediation and hyperaccumulation are emerging innovative technologies for the remediation of arsenic contaminated sites. Natural attenuation may be utilized as a potential in situ remedial option. Further

  12. Residual occurrence and energy property of proteins in HNP model

    NASA Astrophysics Data System (ADS)

    Jiang, Zhou-Ting; Dou, Wen-Hui; Shen, Yu; Sun, Ting-Ting; Xu, Peng

    2015-11-01

    Four categories of globular proteins, including all-α, all-β, α + β, and α/β types, are simplified as the off-lattice HNP model involving the secondary-structural information of each protein. The propensity of three types of residues, i.e., H, N, and P to form a secondary structure is investigated based on 146 protein samples. We find that P residues are easy to form α-helices, whereas H residues have a higher tendency to construct β-sheets. The statistical analysis also indicates that the occurrence of P residues is invariably higher than that of H residues, which is independent of protein category. Changes in bond- and non-bonded potential energies of all protein samples under a wide temperature range are presented by coarse-grained molecular dynamics (MD) simulation. The simulation results clearly show a linear relationship between the bond-stretching/bending potential energy and the reduced temperature. The bond-torsional and non-bonded potential energies show distinct transitions with temperature. The bond-torsional energy increases to the maximum and then decreases with the increase of temperature, which is opposite to the change in non-bonded potential energy. The transition temperature of non-bonded potential energy is independent of the protein category, while that of bond-torsional energy is closely related to the protein secondary structure, i.e., α-helix or β-sheet. The quantitatively bonded- and semi-quantitatively non-bonded potential energy of 24 α + β and 23 α/β protein samples are successfully predicted according to the statistical results obtained from MD simulations. Project supported by the National Natural Science Foundation of China (Grant Nos. 21204078, 11304282, and 11202201) and the Natural Science Foundation of Zhejiang Province, China (Grant No. LY12B04003).

  13. Occurrence of aflatoxins in herbal medicine distributed in South Korea.

    PubMed

    Shim, Won-Bo; Kim, Kyeongyeol; Ofori, Jack A; Chung, Young-Chul; Chung, Duck-Hwa

    2012-11-01

    The objective of this study was to investigate the occurrence of aflatoxins in herbal medicines distributed in South Korea. A total of 700 herbal medicine samples (10 samples each for 70 types of herbal medicine) were analyzed by an enzyme-linked immunosorbent assay (ELISA) for aflatoxin B(1) (AFB(1)), and levels of total aflatoxins were quantified and confirmed by liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). The levels of recovery of the methods were 84.30 to 102.68% (ELISA for AFB(1)) and 72.17 to 90.92% (LC-MS/MS for total aflatoxins). Fifty-eight (8.29%) of 700 samples were AFB(1) positive by ELISA, and 17 (2.43%) of them were finally confirmed as positive for total aflatoxins by LC-MS/MS. Total aflatoxin levels in the herbal medicines were from 4.51 to 108.42 μg/kg. Among the 17 samples, the AFB(1) content of 6 samples (11.95 to 73.27 μg/kg) and the total aflatoxin content of 10 (12.12 to 108.42 μg/kg) samples exceeded the legal limits set by the Korea Food and Drug Administration for AFB(1) (10 μg/kg) and by the European Commission for total aflatoxins (10 μg/kg), respectively. These results demonstrate the risk to consumers of herbal medicine contamination by aflatoxins and encourage further studies to investigate the transfer rate of mycotoxins to decoction, which is the final product for consumption.

  14. Marine Biotoxins: Occurrence, Toxicity, Regulatory Limits and Reference Methods.

    PubMed

    Visciano, Pierina; Schirone, Maria; Berti, Miriam; Milandri, Anna; Tofalo, Rosanna; Suzzi, Giovanna

    2016-01-01

    Harmful algal blooms are natural phenomena caused by the massive growth of phytoplankton that may contain highly toxic chemicals, the so-called marine biotoxins causing illness and even death to both aquatic organisms and humans. Their occurrence has been increased in frequency and severity, suggesting a worldwide public health risk. Marine biotoxins can accumulate in bivalve molluscs and regulatory limits have been set for some classes according to European Union legislation. These compounds can be distinguished in water- and fat-soluble molecules. The first group involves those of Paralytic Shellfish Poisoning and Amnesic Shellfish Poisoning, whereas the toxins soluble in fat can cause Diarrheic Shellfish Poisoning and Neurotoxic Shellfish Poisoning. Due to the lack of long-term toxicity studies, establishing tolerable daily intakes for any of these marine biotoxins was not possible, but an acute reference dose can be considered more appropriate, because these molecules show an acute toxicity. Dietary exposure assessment is linked both to the levels of marine biotoxins present in bivalve molluscs and the portion that could be eaten by consumers. Symptoms may vary from a severe gastrointestinal intoxication with diarrhea, nausea, vomiting, and abdominal cramps to neurological disorders such as ataxia, dizziness, partial paralysis, and respiratory distress. The official method for the detection of marine biotoxins is the mouse bioassay (MBA) showing some limits due to ethical restrictions and insufficient specificity. For this reason, the liquid chromatography-mass spectrometry method has replaced MBA as the reference technique. However, the monitoring of algal blooms producing marine biotoxins should be regularly assessed in order to obtain more reliable, accurate estimates of bloom toxicity and their potential impacts. PMID:27458445

  15. The effect of Q angle on ankle sprain occurrence.

    PubMed

    Pefanis, Nikolaos; Papaharalampous, Xenofon; Tsiganos, Georgios; Papadakou, Eugenia; Baltopoulos, Panagiotis

    2009-02-01

    The intersegmental joint forces and the structures that must resist them (articular surfaces, ligaments, and musculature) are related through anatomical alignment of the joints and skeletal system. Ankle joint structure can affect or be affected by bony malformations of the surrounding areas, including the knee and hip. The aim of the current study is to examine the possible relationship between the quadriceps (Q) angle and other factors (anthropometric characteristics, medical history, and age) on the occurrence of ankle sprains, because its value, when assessed correctly, provides useful information for the anatomical alignment of the lower extremity. The study sample consisted of 45 high-level athletes, evenly distributed among 3 sports (basketball, soccer, and volleyball). Q angle measurements were made on radiographs. The study lasted for 2 years. A logistic regression was used to determine the importance of each factor on the probability in question. A significance level of P = .1 was used. The factors contributing more to an ankle sprain were a previous injury of the same type ( P < .01) followed by body mass index (BMI; P < .10) and age (P < .10). On the contrary, Q angle was proven to be statistically nonsignificant (P > .10). The results were valid even when the BMI variable was substituted by body inertia propensity, a derived variable. The Q angle remained statistically nonsignificant ( P > .10). The Q angle magnitude does not seem to be a decisive factor that could increase the probability of spraining an ankle. The most important factors that could affect the probability of sustaining an ankle sprain are the athlete's age, anthropometric characteristics, and prior injuries. PMID:19825746

  16. Occurrence of Mislabelling in Prepared Fishery Products in Southern Italy

    PubMed Central

    Marchetti, Patrizia; Mottola, Anna; Terio, Valentina; Bottaro, Marilisa; Bonerba, Elisabetta; Bozzo, Giancarlo; Di Pinto, Angela

    2015-01-01

    Fish authentication is a major concern not only for the prevention of commercial fraud, but also for the assessment of safety risks deriving from the undeclared introduction of potentially dangerous toxic or allergenic substances or environmentally damaging fish where endangered species are involved. Moreover, food authentication might affect the diet of certain groups of consumers, such as followers of religious practices. Considering the authentication of fish products is one of the key issues in food safety, quality and sustainability, the aim of this work was to investigate the prevalence of mislabelling in sole (Solea solea), plaice (Pleuronectes platessa), Atlantic salmon (Salmo salar), and hake (Merluccius merluccius) fillets from markets and supermarkets located in Apulia (Southern Italy) using DNA barcoding. The results of the molecular investigations reveal that 42/98 (42.8%) fillet samples were not correctly labelled. In particular, 12/27 (44.4%) fillets of sole (Solea solea) were identified as belonging to Solea senegalensis. In addition, 13/28 (46.4%) plaice (Pleuronectes platessa) samples were identified as Pangasius hypophtalmus. All Atlantic salmon (Salmo salar) samples were correctly labelled. Post-sequencing data analysis revealed that 17/30 (56.6%) hake fillets (Merluccius merluccius) were not correctly labelled, of which 8/30 samples identified as Merluccius hubbsi, 5/30 samples as Merluccius products and 4/30 as Merluccius capensis. The study reveals a high occurrence of species mislabelling in the prepared fish fillet products, further evidence of the need for increased traceability and assessment of the authenticity of food products. PMID:27800410

  17. Widespread occurrence of bd in French Guiana, South America.

    PubMed

    Courtois, Elodie A; Gaucher, Philippe; Chave, Jérôme; Schmeller, Dirk S

    2015-01-01

    The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) is a purported agent of decline and extinction of many amphibian populations worldwide. Its occurrence remains poorly documented in many tropical regions, including the Guiana Shield, despite the area's high amphibian diversity. We conducted a comprehensive assessment of Bd in French Guiana in order to (1) determine its geographical distribution, (2) test variation of Bd prevalence among species in French Guiana and compare it to earlier reported values in other South American anuran species (http://www.bd-maps.net; 123 species from 15 genera) to define sentinel species for future work, (3) track changes in prevalence through time and (4) determine if Bd presence had a negative effect on one selected species. We tested the presence of Bd in 14 species at 11 sites for a total of 1053 samples (306 in 2009 and 747 in 2012). At least one Bd-positive individual was found at eight out of 11 sites, suggesting a wide distribution of Bd in French Guiana. The pathogen was not uniformly distributed among the studied amphibian hosts, with Dendrobatidae species displaying the highest prevalence (12.4%) as compared to Bufonidae (2.6 %) and Hylidae (1.5%). In contrast to earlier reported values, we found highest prevalence for three Dendrobatidae species and two of them displayed an increase in Bd prevalence from 2009 to 2012. Those three species might be the sentinel species of choice for French Guiana. For Dendrobates tinctorius, of key conservation value in the Guiana Shield, smaller female individuals were more likely to be infected, suggesting either that frogs can outgrow their chytrid infections or that the disease induces developmental stress limiting growth. Generally, our study supports the idea that Bd is more widespread than previously thought and occurs at remote places in the lowland forest of the Guiana shield. PMID:25902035

  18. Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates.

    PubMed Central

    Anderson, A J; Dawes, E A

    1990-01-01

    Polyhydroxyalkanoates (PHAs), of which polyhydroxybutyrate (PHB) is the most abundant, are bacterial carbon and energy reserve materials of widespread occurrence. They are composed of 3-hydroxyacid monomer units and exist as a small number of cytoplasmic granules per cell. The properties of the C4 homopolymer PHB as a biodegradable thermoplastic first attracted industrial attention more than 20 years ago. Copolymers of C4 (3-hydroxybutyrate [3HB]) and C5 (3-hydroxyvalerate [3HV]) monomer units have modified physical properties; e.g., the plastic is less brittle than PHB, whereas PHAs containing C8 to C12 monomers behave as elastomers. This family of materials is the centre of considerable commercial interest, and 3HB-co-3HV copolymers have been marketed by ICI plc as Biopol. The known polymers exist as 2(1) helices with the fiber repeat decreasing from 0.596 nm for PHB to about 0.45 nm for C8 to C10 polymers. Novel copolymers with a backbone of 3HB and 4HB have been obtained. The native granules contain noncrystalline polymer, and water may possibly act as a plasticizer. Although the biosynthesis and regulation of PHB are generally well understood, the corresponding information for the synthesis of long-side-chain PHAs from alkanes, alcohols, and organic acids is still incomplete. The precise mechanisms of action of the polymerizing and depolymerizing enzymes also remain to be established. The structural genes for the three key enzymes of PHB synthesis from acetyl coenzyme A in Alcaligenes eutrophus have been cloned, sequenced, and expressed in Escherichia coli. Polymer molecular weights appear to be species specific. The factors influencing the commercial choice of organism, substrate, and isolation process are discussed. The physiological functions of PHB as a reserve material and in symbiotic nitrogen fixation and its presence in bacterial plasma membranes and putative role in transformability and calcium signaling are also considered. PMID:2087222

  19. Catalog of worldwide tidal bore occurrences and characteristics

    USGS Publications Warehouse

    Bartsch-Winkler, S.; Lynch, David K.

    1988-01-01

    Documentation of tidal bore phenomena occurring throughout the world aids in defining the typical geographical setting of tidal bores and enables prediction of their occurrence in remote areas. Tidal bores are naturally occurring, tidally generated, solitary, moving water waves up to 6 meters in height that form upstream in estuaries with semidiurnal or nearly semidiurnal tide ranges exceeding 4 meters. Estuarine settings that have tidal bores typically include meandering fluvial systems with shallow gradients. Bores are well defined, having amplitudes greater than wind- or turbulence-caused waves, and may be undular or breaking. Formation of a bore is dependent on depth and velocity of the incoming tide and river outflow. Bores may occur in series (in several channels) or in succession (marking each tidal pulse). Tidal bores propagate up tidal estuaries a greater distance than the width of the estuary and most occur within 100 kilometers upstream of the estuary mouth. Because they are dynamic, bores cause difficulties in some shipping ports and are targets for eradication. Tidal bores are known to occur, or to have occurred in the recent past, in at least 67 localities in 16 countries at all latitudes, including every continent except Antarctica. Parts of Argentina, Canada, Central America, China, Mozambique, Madagascar, Northern Europe, North and South Korea, the United Kingdom, and the U.S.S.R. probably have additional undiscovered or unreported tidal bores. In Turnagain Arm estuary in Alaska, bores cause an abrupt increase in salinity, suspended sediment, surface character, and bottom pressure, a decrease in illumination of the water column, and a change in water temperature. Tidal bores occurring in Turnagain Arm, Alaska, have the

  20. Assessing historical rate changes in global tsunami occurrence

    USGS Publications Warehouse

    Geist, E.L.; Parsons, T.

    2011-01-01

    The global catalogue of tsunami events is examined to determine if transient variations in tsunami rates are consistent with a Poisson process commonly assumed for tsunami hazard assessments. The primary data analyzed are tsunamis with maximum sizes >1m. The record of these tsunamis appears to be complete since approximately 1890. A secondary data set of tsunamis >0.1m is also analyzed that appears to be complete since approximately 1960. Various kernel density estimates used to determine the rate distribution with time indicate a prominent rate change in global tsunamis during the mid-1990s. Less prominent rate changes occur in the early- and mid-20th century. To determine whether these rate fluctuations are anomalous, the distribution of annual event numbers for the tsunami catalogue is compared to Poisson and negative binomial distributions, the latter of which includes the effects of temporal clustering. Compared to a Poisson distribution, the negative binomial distribution model provides a consistent fit to tsunami event numbers for the >1m data set, but the Poisson null hypothesis cannot be falsified for the shorter duration >0.1m data set. Temporal clustering of tsunami sources is also indicated by the distribution of interevent times for both data sets. Tsunami event clusters consist only of two to four events, in contrast to protracted sequences of earthquakes that make up foreshock-main shock-aftershock sequences. From past studies of seismicity, it is likely that there is a physical triggering mechanism responsible for events within the tsunami source 'mini-clusters'. In conclusion, prominent transient rate increases in the occurrence of global tsunamis appear to be caused by temporal grouping of geographically distinct mini-clusters, in addition to the random preferential location of global M >7 earthquakes along offshore fault zones.

  1. Occurrence and source characterization of perfluorochemicals in an urban watershed.

    PubMed

    Nguyen, Viet Tung; Reinhard, Martin; Karina, Gin Yew-Hoong

    2011-02-01

    Perfluorochemicals (PFCs) are used in numerous applications, mainly as surfactants, and occur ubiquitously in the environment as complex mixtures. This study was undertaken to characterize the occurrence and sources of commonly detected PFC compounds in surface waters of the Marina catchment, a watershed that drains an urbanized section of Singapore. Of the 19 target PFCs, 13 were detected with perfluorooctanoic acid (PFOA) (5-31 ng L(-1)) and perfluorooctane sulfonate (PFOS) (1-156 ng L(-1)) being the dominant components. Other compounds detected included perfluoroalkyl carboxylates (C7-C12) and perfluoroalkyl sulfonates (C6 and C8). Sulfonamide compounds detected 2-(N-ethylperfluorooctanesulfonamido) acetic acid (N-EtFOSAA), 2-(N-methylperfluorooctanesulfonamido) acetic acid (N-MeFOSAA), perfluorooctanesulfonamido acetic acid (FOSAA) and perfluorooctanesulfonamide (FOSA) were putative transformation products of N-EtFOSE and N-MeFOSE, the N-ethylated and N-methylated ethyl alcohol derivatives, respectively. Surface water concentrations were generally higher during dry weather than during storm water flow: the median concentrations of total PFCs in dry and wet weather were 57 and 138 ng L(-1) compared to 42 and 79 ng L(-1), respectively, at Stamford and Alexandra canal, suggesting the presence of a continuous source(s) which is subject to dilution during storm events. In rain water, median concentrations were 6.4 ng L(-1), suggesting rain contributed from 12-25% to the total PFC load for non-point source sites. The longitudinal concentration profile along one of the canals revealed a point source of sulfonated PFCs (PFOS), believed to originate from aqueous film-forming foam (AFFF). Sources were characterized using principal component analysis (PCA) and by plotting PFHxS/PFOA against PFOS/PFOA. Typical surface waters exhibit PFOS/PFOA and PFHxS/PFOA ratios below 0.9 and 0.5, respectively. PCA plots reveal waters impacted by "non-typical" PFC sources in Alexandra

  2. Occurrence and sources of perfluoroalkyl acids in Italian river basins.

    PubMed

    Valsecchi, Sara; Rusconi, Marianna; Mazzoni, Michela; Viviano, Gaetano; Pagnotta, Romano; Zaghi, Carlo; Serrini, Giuliana; Polesello, Stefano

    2015-06-01

    This paper presents a survey on the occurrence and sources of 11 perfluoroalkyl acids (PFAA) in the main river basins in Italy, covering about 40% of the Italian surface area and 45% of the Italian population. Total concentrations of PFAA ranged from

  3. Very large hail occurrence in Poland from 2007 to 2015

    NASA Astrophysics Data System (ADS)

    Pilorz, Wojciech

    2015-10-01

    Very large hail is known as a presence of a hailstone greater or equal to 5 cm in diameter. This phenomenon is rare but its significant consequences, not only to agriculture but also to automobiles, households and people outdoor makes it essential thing to examine. Hail appearance is strictly connected with storms frequency and its kind. The most hail-endangered kind of storm is supercell storm. Geographical distribution of hailstorms was compared with geographical distribution of storms in Poland. Similarities were found. The area of the largest number of storms is southeastern Poland. Analyzed European Severe Weather Database (ESWD) data showed that most of very large hail reports occurred in this part of Poland. The probable reason for this situation is the longest period of lasting tropical airmasses in southeastern Poland. Spatial distribution analysis shows also more hail incidents over Upper Silesia, Lesser Poland, Subcarpathia and Świętokrzyskie regions. The information source about hail occurrence was ESWD - open database, where everyone can add report and find reports which meet given search criteria. 69 hailstorms in the period of 2007 - 2015 were examined. They caused 121 very large hail reports. It was found that there is large disproportion in number of hailstorms and hail reports between individual years. Very large hail season in Poland begins in May and ends in September with cumulation in July. Most of hail occurs between 12:00 and 17:00 UTC, but there were some cases of very large (one extremely large) hail at night and early morning hours. However very large hail is a spectacular phenomenon, its local character determines potentially high information loss rate and it is the most significant problem in hail research.

  4. Occurrence of Aflatoxins Contamination in Brown Rice from Pakistan

    PubMed Central

    ASGHAR, Muhammad Asif; IQBAL, Javed; AHMED, Aftab; KHAN, Mobeen Ahmed

    2014-01-01

    Abstract Background The objective of this study was to determine the distribution of an economically–important class of mycotoxins, the aflatoxins (AFs) in Pakistani Brown Rice. Methods A total of 262 of brown rice samples were collected from different vendors during July 2006 to June 2011. Samples were analyzed for the occurrence of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) by thin layer chromatography (TLC) technique. Results AFB1 was detected in 250 (95.4%) samples, whereas AFB2 was detected in 20 (7.6%) samples. Furthermore, AFG1 and AFG2 were not found in any sample. The contamination range of AFB1 and AFB2 was found 1.07–24.65 μg/kg and 0.52–2.62 μg/kg, respectively. Total AFs were quantified in 250 (95.4%) samples with an average of 3.89 μg/kg and contamination range was noted to be between 1.07–27.27 μg/kg. The overall results indicated that in 12 (4.6%) samples, AFs were not found within detectable limits. Furthermore, in 188 (71.7%) samples, AFs level was found below than maximum tolerated levels (MTL) as recommended by the European Union (4 μg/kg). Moreover, in 61 (23.3%) samples, AFs range was found between 4–20 μg/kg, which were fit for human consumption as per MTL (20 μg/kg) assigned by USA (FDA and FAO) and Pakistan (PSQCA). While only one sample (27.27 μg/kg) exceeded the above mention regulation limits. Conclusion Low level of AFs occurs frequently in brown rice, and can be improved using proper harvesting practices, storage and transportation conditions. The small quantities of AFs warrant performing further investigation, monitoring and routine analysis on regular basis. PMID:25988088

  5. Occurrence of Potentially Pathogenic Bacterial-Endosymbionts in Acanthamoeba Spp.

    PubMed Central

    NIYYATI, Maryam; MAFI, Mahyar; HAGHIGHI, Ali; HAKEMI VALA, Mojdeh

    2015-01-01

    Background: Acanthamoeba- bacteria interactions enable pathogenic bacteria to tolerate harsh conditions and lead to transmission to the susceptible host. The present study was aimed to address the presence of bacterial endosymbionts of Acanthamoeba isolated from recreational water sources of Tehran, Iran. To the best of our knowledge this is the first study regarding occurrence of bacteria in environmental Acanthamoeba spp. in Iran. Methods: A total of 75 samples of recreational water sources were collected. Samples were cultured on non- nutrient agar 1.5% plates. Positive Acanthamoeba spp. were axenically grown. DNA extraction and PCR reaction was performed using JDP1-2 primers. All positive samples of Acanthamoeba were examined for the presence of endosymbionts using staining and molecular methods. The PCR products were then sequenced in order to determine the genotypes of Acanthamoeba and bacteria genera. Results: Out of 75 samples, 16 (21.3%) plates were positive for Acanthamoeba according to the morphological criteria. Molecular analysis revealed that Acanthamoeba belonged to T4 and T5 genotypes. Five isolates (35.7%) were positive for bacterial endosymbionts using staining method and PCR test. Sequencing of PCR products confirmed the presence of Pseudomonas aeruginosa and Agrobacterium tumefasiens. Conclusion: The presence of Acanthamoeba bearing pathogenic endosymbionts in water sources leads us to public health issues including improved sanitation and decontamination measures in recreational water sources in order to prevent amoebae-related infection. To the best of our knowledge this is the first report regarding the isolation of A. tumefasiens from Acanthamoeba in Iran and worldwide. PMID:26246815

  6. Multicentric occurrence of hepatocellular carcinoma with nonalcoholic steatohepatitis

    PubMed Central

    Kawai, Hirokazu; Nomoto, Minoru; Suda, Takeshi; Kamimura, Kenya; Tsuchiya, Atsunori; Tamura, Yasushi; Yano, Masahiko; Takamura, Masaaki; Igarashi, Masato; Wakai, Toshifumi; Yamagiwa, Satoshi; Matsuda, Yasunobu; Ohkoshi, Shogo; Kurosaki, Isao; Shirai, Yoshio; Okada, Masahiko; Aoyagi, Yutaka

    2011-01-01

    AIM: To reveal the manner of hepatocellular carcinoma (HCC) development in patients with nonalcoholic steatohepatitis (NASH) focusing on multicentric occurrence (MO) of HCC. METHODS: We compared clinicopathological characteristics between patients with and without MO of HCC arising from NASH background. The clinical features were implicated with reference to the literature available. RESULTS: MO of HCC was identified with histological proof in 4 out of 12 patients with NASH-related HCC (2 males and 2 females). One patient had synchronous MO; an advanced HCC, two well-differentiated HCCs and a dysplastic nodule, followed by the development of metachronous MO of HCC. The other three patients had multiple advanced HCCs accompanied by a well-differentiated HCC or a dysplastic nodule. Of these three patients, one had synchronous MO, one had metachronous MO and the other had both synchronous and metachronous MO. There were no obvious differences between the patients with or without MO in terms of liver function tests, tumor markers and anatomical extent of HCC. On the other hand, all four patients with MO of HCC were older than 70 years old and had the comorbidities of obesity, type 2 diabetes mellitus (T2DM), hypertension and cirrhosis. Although these conditions were not limited to MO of HCC, all the conditions were met in only one of eight patients without MO of HCC. Thus, concurrence of these conditions may be a predisposing situation to synchronous MO of HCC. In particular, old age, T2DM and cirrhosis were suggested to be prerequisite for MO because these factors were depicted in common among two other cases with MO of HCC under NASH in the literature. CONCLUSION: The putative predisposing factors and necessary preconditions for synchronous MO of HCC in NASH were suggested in this study. Further investigations are required to clarify the accurate prevalence and predictors of MO to establish better strategies for treatment and prevention leading to the prognostic

  7. Marine Biotoxins: Occurrence, Toxicity, Regulatory Limits and Reference Methods

    PubMed Central

    Visciano, Pierina; Schirone, Maria; Berti, Miriam; Milandri, Anna; Tofalo, Rosanna; Suzzi, Giovanna

    2016-01-01

    Harmful algal blooms are natural phenomena caused by the massive growth of phytoplankton that may contain highly toxic chemicals, the so-called marine biotoxins causing illness and even death to both aquatic organisms and humans. Their occurrence has been increased in frequency and severity, suggesting a worldwide public health risk. Marine biotoxins can accumulate in bivalve molluscs and regulatory limits have been set for some classes according to European Union legislation. These compounds can be distinguished in water- and fat-soluble molecules. The first group involves those of Paralytic Shellfish Poisoning and Amnesic Shellfish Poisoning, whereas the toxins soluble in fat can cause Diarrheic Shellfish Poisoning and Neurotoxic Shellfish Poisoning. Due to the lack of long-term toxicity studies, establishing tolerable daily intakes for any of these marine biotoxins was not possible, but an acute reference dose can be considered more appropriate, because these molecules show an acute toxicity. Dietary exposure assessment is linked both to the levels of marine biotoxins present in bivalve molluscs and the portion that could be eaten by consumers. Symptoms may vary from a severe gastrointestinal intoxication with diarrhea, nausea, vomiting, and abdominal cramps to neurological disorders such as ataxia, dizziness, partial paralysis, and respiratory distress. The official method for the detection of marine biotoxins is the mouse bioassay (MBA) showing some limits due to ethical restrictions and insufficient specificity. For this reason, the liquid chromatography–mass spectrometry method has replaced MBA as the reference technique. However, the monitoring of algal blooms producing marine biotoxins should be regularly assessed in order to obtain more reliable, accurate estimates of bloom toxicity and their potential impacts. PMID:27458445

  8. Derivation Of the Occurrence Of Multiple Planets In Transit

    NASA Technical Reports Server (NTRS)

    Koch, D.; Witteborn, Fred C. (Technical Monitor)

    1995-01-01

    All methods for extra-solar planet detection have their advantages and drawbacks. In photometry, for a planet to be detectable, it must pass in front of its star along the line of sight to the star. This may seem at first to be an unusual event, when in fact it has been shown to be equal to d*/D, or about 1% for planetary systems like our own (d* is the stellar diameter and D is the orbital diameter). Planetary scientists are interested in the complexities of an entire system rather than just a single planet. At first it might seem extremely unlikely that multiple planets would be detectable. But imagine having detected a planet in transit and that the relative inclinations, phi, of all the orbits is smaller than d*/D. Then, if you detect one planet, you should detect nearly all of them. However, for the solar system phi greater than d*/D, but still small. The exact derivation will be presented for the occurrence of multiple plane's in transit. A good approximation to the result is found to be given by (4/pi(phi)(d*/D(sub 2)), where D(sub 2) is the orbit of the second planet. For example if phi is 2 deg, then the probability for finding a second planet if it has an inclination less than phi will be equal to 36 d*/D(sub 2). For inner planets around solar-like stars, this turns out to be on the order of 20% of the systems detected. Extending this to three planets, such as for Venus, Earth and Mars, the probability would be 4%.

  9. Marine Biotoxins: Occurrence, Toxicity, Regulatory Limits and Reference Methods.

    PubMed

    Visciano, Pierina; Schirone, Maria; Berti, Miriam; Milandri, Anna; Tofalo, Rosanna; Suzzi, Giovanna

    2016-01-01

    Harmful algal blooms are natural phenomena caused by the massive growth of phytoplankton that may contain highly toxic chemicals, the so-called marine biotoxins causing illness and even death to both aquatic organisms and humans. Their occurrence has been increased in frequency and severity, suggesting a worldwide public health risk. Marine biotoxins can accumulate in bivalve molluscs and regulatory limits have been set for some classes according to European Union legislation. These compounds can be distinguished in water- and fat-soluble molecules. The first group involves those of Paralytic Shellfish Poisoning and Amnesic Shellfish Poisoning, whereas the toxins soluble in fat can cause Diarrheic Shellfish Poisoning and Neurotoxic Shellfish Poisoning. Due to the lack of long-term toxicity studies, establishing tolerable daily intakes for any of these marine biotoxins was not possible, but an acute reference dose can be considered more appropriate, because these molecules show an acute toxicity. Dietary exposure assessment is linked both to the levels of marine biotoxins present in bivalve molluscs and the portion that could be eaten by consumers. Symptoms may vary from a severe gastrointestinal intoxication with diarrhea, nausea, vomiting, and abdominal cramps to neurological disorders such as ataxia, dizziness, partial paralysis, and respiratory distress. The official method for the detection of marine biotoxins is the mouse bioassay (MBA) showing some limits due to ethical restrictions and insufficient specificity. For this reason, the liquid chromatography-mass spectrometry method has replaced MBA as the reference technique. However, the monitoring of algal blooms producing marine biotoxins should be regularly assessed in order to obtain more reliable, accurate estimates of bloom toxicity and their potential impacts.

  10. Occurrence of perfluoroalkyl acids in environmental waters in Vietnam.

    PubMed

    Duong, Hanh Thi; Kadokami, Kiwao; Shirasaka, Hanako; Hidaka, Rento; Chau, Hong Thi Cam; Kong, Lingxiao; Nguyen, Trung Quang; Nguyen, Thao Thanh

    2015-03-01

    This is the first nationwide study of perfluoroalkyl acids (PFAAs) in environmental waters in Vietnam. Twenty-eight river water and 22 groundwater samples collected in four major cities and 14 river water samples from the Red River were screened to investigate the occurrence and sources of 16 PFAAs. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were the most prevalent of 11 detected PFAAs with maximum concentrations in urban river water of 5.3, 18 and 0.93ngL(-1), respectively, and in groundwater of 8.2, 4.5 and 0.45ngL(-1), respectively. PFAAs in the Red River water were detected at low levels. PFAA concentrations in river water were higher in the rainy season than in the dry season, possibly due to storm water runoff, a common phenomenon in Southeast Asian countries. The highest concentrations of PFAAs in river water were observed in samples from highly populated and industrialized areas, perhaps sourced from sewage. The PFAA concentrations observed were similar to those in other Southeast Asian countries, but lower than in developed nations. From the composition profiles of PFAAs, industrial products containing PFAAs imported from China and Japan might be one of the major sources of PFAAs in the Vietnamese aquatic environment. According to the health-based values and advisory issued by the United States Environmental Protection Agency (USEPA), the concentrations of detected PFAAs in this study do not pose an immediate health risk to humans and aquatic organisms. PMID:25496738

  11. Occurrence of microcystin-producing cyanobacteria in Ugandan freshwater habitats

    PubMed Central

    Okello, William; Portmann, Cyril; Erhard, Marcel; Gademann, Karl; Kurmayer, Rainer

    2011-01-01

    Microcystins (MCs) are cyclic heptapeptides that are the most abundant toxins produced by cyanobacteria in freshwater. The phytoplankton of many freshwater lakes in Eastern Africa is dominated by cyanobacteria. Less is known, however, on the occurrence of MC producers and the production of MCs. Twelve Ugandan freshwater habitats ranging from mesotrophic to hypertrophic conditions were sampled in May and June of 2004 and April of 2008 and were analyzed for their physico-chemical parameters, phytoplankton composition, and MC concentrations. Among the group of the potential MC-producing cyanobacteria, Anabaena (0 - 107 cells ml−1) and Microcystis (103 - 107 cells ml−1) occurred most frequently and dominated in eutrophic systems. A significant linear relationship (n = 31, r2 = 0.38, p < 0.001) between the Microcystis cell numbers and MC concentration (1.3-93 fg of MC cell−1) was observed. Beside [MeAsp3, Mdha7]-MC-RR two new microcystins, [Asp3]-MC-RY and [MeAsp3]-MC-RY were isolated and their constitution assigned by LC-MS2. In order to identify the MC-producing organism in the water samples (i), the conserved aminotransferase domain part of the mcyE gene that is indicative of MC production was amplified by general primers and cloned and sequenced, and (ii), genus-specific primers were used to amplify the mcyE gene of the genera Microcystis, Anabaena, and Planktothrix. Only mcyE genotypes that are indicative of Microcystis sp. were obtained via the environmental cloning approach (337 bp, 96.1%-96.7% similarity to the Microcystis aeruginosa strain PCC7806). Accordingly, only the mcyE primers, which are specific for Microcystis, revealed PCR products. We concluded that Microcystis is the major MC-producer in Ugandan freshwater. PMID:19609871

  12. Identification of geopressured occurrences outside of the Gulf Coast

    SciTech Connect

    Strongin, O.

    1981-03-05

    The work focused on the occurrences of geopressures in Appalachia and selected California basins. In the former region, where geopressures have been observed, the pressure gradients for the most part were only slightly above normal as in the case of the Oriskany formation of Devonian age; this unit was also characterized by extremely high salinity. The one notable exception was in the Rome trough of West Virginia where Cambrian beds at depths below 10,000 feet display very high geopressures, approaching the lithostatic gradient, and the waters are only moderately saline. Though the geothermal gradient throughout Appalachian is relatively low, even in the Rome trough, the pressure, temperature and salinity values in this area indicate that the methane content of the Cambrian formation waters is in the range of 30 to 35 SCF/barrel. The two California areas researched included the contiguous Sacramento and San Joaquin Valleys. In the first, geopressures have been principally encountered in the Forbes formation of Cretaceous age, often at very shallow depths. Further waters are invariably characterized by very low salinity, far below the salinity of normal sea water, while the geothermal gradient in apparently higher in geopressured than in normally pressured zones. In the San Joaquin Valley, geopressures are particularly noteworthy in at least two formations of Miocene age at depths generally greater than those of the Forbes. The formation waters are likewise low in salinity; however, the geothemal gradient, especially in the geopressured zones on the west side of the valley, can be extremely high, up to twice as much as the normal temperature gradient. In view of these conditions, it is estimated that in the western San Joaquin Valley the methane content of geopressured formation waters will range from 30 to 40 SCF/barrel while in the Sacramento Valley, the methane content is estimated to be 20 to 25 SCF/barrel.

  13. Pulmonary tuberculosis and lung cancer: simultaneous and sequential occurrence*

    PubMed Central

    Silva, Denise Rossato; Valentini, Dirceu Felipe; Müller, Alice Mânica; de Almeida, Carlos Podalirio Borges; Dalcin, Paulo de Tarso Roth

    2013-01-01

    OBJECTIVE: Lung cancer (LC) is the leading cause of cancer-related death and represents a major public health problem worldwide. Another major cause of morbidity and mortality, especially in developing countries, is tuberculosis. The simultaneous or sequential occurrence of pulmonary tuberculosis and LC in the same patient has been reported in various case series and case-control studies. The objective of this study was to describe the characteristics of patients developing tuberculosis and LC, either simultaneously or sequentially. METHODS: This was a cross-sectional study based on the review of medical charts. RESULTS: The study involved 24 patients diagnosed with tuberculosis and LC between 2009 and 2012. The diagnoses of tuberculosis and LC occurred simultaneously in 10 patients, whereas tuberculosis was diagnosed prior to LC in 14. The median time between the two diagnoses was 5 years (interquartile range: 1-30 years). Fourteen patients (58.3%) were male, 20 (83.3%) were White, and 22 (91.7%) were smokers or former smokers. The most common histological type was adenocarcinoma, identified in 14 cases (58.3%), followed by epidermoid carcinoma, identified in 6 (25.0%). Seven patients (29.2%) presented with distant metastases at diagnosis; of those 7 patients, 5 (71%) were diagnosed with LC and tuberculosis simultaneously. CONCLUSIONS: In the present study, most of the patients with tuberculosis and LC were smokers or former smokers, and tuberculosis was diagnosed either before or simultaneously with LC. Non-small cell lung cancer, especially adenocarcinoma, was the most common histological type. PMID:24068271

  14. Widespread occurrence of bd in French Guiana, South America.

    PubMed

    Courtois, Elodie A; Gaucher, Philippe; Chave, Jérôme; Schmeller, Dirk S

    2015-01-01

    The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) is a purported agent of decline and extinction of many amphibian populations worldwide. Its occurrence remains poorly documented in many tropical regions, including the Guiana Shield, despite the area's high amphibian diversity. We conducted a comprehensive assessment of Bd in French Guiana in order to (1) determine its geographical distribution, (2) test variation of Bd prevalence among species in French Guiana and compare it to earlier reported values in other South American anuran species (http://www.bd-maps.net; 123 species from 15 genera) to define sentinel species for future work, (3) track changes in prevalence through time and (4) determine if Bd presence had a negative effect on one selected species. We tested the presence of Bd in 14 species at 11 sites for a total of 1053 samples (306 in 2009 and 747 in 2012). At least one Bd-positive individual was found at eight out of 11 sites, suggesting a wide distribution of Bd in French Guiana. The pathogen was not uniformly distributed among the studied amphibian hosts, with Dendrobatidae species displaying the highest prevalence (12.4%) as compared to Bufonidae (2.6 %) and Hylidae (1.5%). In contrast to earlier reported values, we found highest prevalence for three Dendrobatidae species and two of them displayed an increase in Bd prevalence from 2009 to 2012. Those three species might be the sentinel species of choice for French Guiana. For Dendrobates tinctorius, of key conservation value in the Guiana Shield, smaller female individuals were more likely to be infected, suggesting either that frogs can outgrow their chytrid infections or that the disease induces developmental stress limiting growth. Generally, our study supports the idea that Bd is more widespread than previously thought and occurs at remote places in the lowland forest of the Guiana shield.

  15. Occurrence of enniatins and beauvericin in 60 Chinese medicinal herbs.

    PubMed

    Hu, Ling; Rychlik, Michael

    2014-01-01

    A total of 60 Chinese medicinal herbs were examined for contamination of the emerging Fusarium mycotoxins enniatins (ENNs) A, A1, B, B1 and beauvericin (BEA). The herbs under study are commonly used in China as both medicines and food. The dried samples of herbs were randomly collected from traditional Chinese medicine stores in Zhejiang province, China. Sample preparation was achieved by methanol extraction, followed by a simple membrane filtration step; no tedious clean-ups were involved. ENNs A, A1, B, B1 and BEA were analysed by the recently developed stable isotope dilution assays, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). With limits of detection ranging between 0.8 and 1.2 µg kg(-1) for the analytes under study, 25% of all analysed samples were contaminated with at least one of the ENNs and BEA. BEA was the most frequently detected toxin with a 20% incidence in all samples. The percentages of ENN-positive samples were lower: each single ENN was detected in 6.7-11.7% of all samples. Considering the total amounts of the five mycotoxins in single samples, values between 2.5 and 751 µg kg(-1) were found. The mean total amount in positive samples was 126 µg kg(-1). Regarding ginger, the frequent occurrence of ENNs and BEA in dried ginger could be confirmed in samples from Germany. However, in fresh ginger root the toxins were not detectable. This is the first report on the presence of ENNs and BEA in Chinese medicinal herbs.

  16. Occurrence of endocrine-disrupting chemicals in indoor dust

    PubMed Central

    Hwang, Hyun-Min; Park, Eun-Kee; Young, Thomas M.; Hammock, Bruce D.

    2010-01-01

    Human exposure to indoor dust enriched with endocrine-disrupting chemicals released from numerous indoor sources has been a focus of increasing concern. Longer residence times and elevated contaminant concentrations in the indoor environment may increase chances of exposure to these contaminants by 1000-fold compared to outdoor exposure. To investigate the occurrence of semi-volatile endocrine-disrupting chemicals, including PBDEs (polybrominated diphenyl ethers), PCBs (polychlorinated biphenyls), phthalates, pyrethroids, DDT (dichlorodiphenyltrichloroethane) and its metabolites, and chlordanes, indoor dust samples were collected from household vacuum cleaner bags provided by 10 apartments and 1 community hall in Davis, California, USA. Chemical analyses show that all indoor dust samples are highly contaminated by target analytes measured in the present study. Di-(2-ethylhexyl)phthalate was the most abundant (104–7630 μg/g) in all samples and higher than other target analytes by 2 to 6 orders of magnitude. PBDEs were also found at high concentrations (1780–25,200 ng/g). Although the use of PCBs has been banned or restricted for decades, some samples had PCBs at levels that are considered to be concerns for human health, indicating that the potential risk posed by PCBs still remains high in the indoor environment, probably due to a lack of dissipation processes and continuous release from the sources. Although the use of some PBDEs is being phased out in some parts of the U.S., this trend may apply to PBDEs as well. We can anticipate that exposure to PBDEs will continue as long as the general public keeps using existing household items such as sofas, mattresses, and carpets that contain PBDEs. This study provides additional information that indoor dust is highly contaminated by persistent and endocrine-disrupting chemicals. PMID:18632138

  17. Occurrence and Potential Biological Effects of Amphetamine on Stream Communities.

    PubMed

    Lee, Sylvia S; Paspalof, Alexis M; Snow, Daniel D; Richmond, Erinn K; Rosi-Marshall, Emma J; Kelly, John J

    2016-09-01

    The presence of pharmaceuticals, including illicit drugs in aquatic systems, is a topic of environmental significance because of their global occurrence and potential effects on aquatic ecosystems and human health, but few studies have examined the ecological effects of illicit drugs. We conducted a survey of several drug residues, including the potentially illicit drug amphetamine, at 6 stream sites along an urban to rural gradient in Baltimore, Maryland, U.S.A. We detected numerous drugs, including amphetamine (3 to 630 ng L(-1)), in all stream sites. We examined the fate and ecological effects of amphetamine on biofilm, seston, and aquatic insect communities in artificial streams exposed to an environmentally relevant concentration (1 μg L(-1)) of amphetamine. The amphetamine parent compound decreased in the artificial streams from less than 1 μg L(-1) on day 1 to 0.11 μg L(-1) on day 22. In artificial streams treated with amphetamine, there was up to 45% lower biofilm chlorophyll a per ash-free dry mass, 85% lower biofilm gross primary production, 24% greater seston ash-free dry mass, and 30% lower seston community respiration compared to control streams. Exposing streams to amphetamine also changed the composition of bacterial and diatom communities in biofilms at day 21 and increased cumulative dipteran emergence by 65% and 89% during the first and third weeks of the experiment, respectively. This study demonstrates that amphetamine and other biologically active drugs are present in urban streams and have the potential to affect both structure and function of stream communities. PMID:27513635

  18. The effect of Q angle on ankle sprain occurrence.

    PubMed

    Pefanis, Nikolaos; Papaharalampous, Xenofon; Tsiganos, Georgios; Papadakou, Eugenia; Baltopoulos, Panagiotis

    2009-02-01

    The intersegmental joint forces and the structures that must resist them (articular surfaces, ligaments, and musculature) are related through anatomical alignment of the joints and skeletal system. Ankle joint structure can affect or be affected by bony malformations of the surrounding areas, including the knee and hip. The aim of the current study is to examine the possible relationship between the quadriceps (Q) angle and other factors (anthropometric characteristics, medical history, and age) on the occurrence of ankle sprains, because its value, when assessed correctly, provides useful information for the anatomical alignment of the lower extremity. The study sample consisted of 45 high-level athletes, evenly distributed among 3 sports (basketball, soccer, and volleyball). Q angle measurements were made on radiographs. The study lasted for 2 years. A logistic regression was used to determine the importance of each factor on the probability in question. A significance level of P = .1 was used. The factors contributing more to an ankle sprain were a previous injury of the same type ( P < .01) followed by body mass index (BMI; P < .10) and age (P < .10). On the contrary, Q angle was proven to be statistically nonsignificant (P > .10). The results were valid even when the BMI variable was substituted by body inertia propensity, a derived variable. The Q angle remained statistically nonsignificant ( P > .10). The Q angle magnitude does not seem to be a decisive factor that could increase the probability of spraining an ankle. The most important factors that could affect the probability of sustaining an ankle sprain are the athlete's age, anthropometric characteristics, and prior injuries.

  19. Post-midnight occurrence of equatorial plasma bubbles

    NASA Astrophysics Data System (ADS)

    Ajith, K. K.; Otsuka, Yuichi; Yamamoto, Mamoru; Yokoyama, Tatsuhiro; Tulasiram, S.

    2016-07-01

    The equatorial plasma bubbles (EPBs)/equatorial spread F (ESF) irregularities are an important topic of space weather interest because of their impact on transionospheric radio communications, satellite-based navigation and augmentation systems. This local plasma depleted structures develop at the bottom side F layer through Rayleigh-Taylor instability and rapidly grow to topside ionosphere via polarization electric fields within them. The steep vertical gradients due to quick loss of bottom side ionization and rapid uplift of equatorial F layer via prereversal enhancement (PRE) of zonal electric field makes the post-sunset hours as the most preferred local time for the formation of EPBs. However, there is a different class of irregularities that occurs during the post-midnight hours of June solstice reported by the previous studies. The occurrence of these post-midnight EPBs maximize during the low solar activity periods. The growth characteristics and the responsible mechanism for the formation of these post-midnight EPBs are not yet understood. Using the rapid beam steering ability of 47 MHz Equatorial Atmosphere Radar (EAR) at Kototabang (0.2°S geographic latitude, 100.3°E geographic longitude, and 10.4°S geomagnetic latitude), Indonesia, the spatial and temporal evolution of equatorial plasma bubbles (EPBs) were examined to classify the evolutionary-type EPBs from those which formed elsewhere and drifted into the field of view of radar. The responsible mechanism for the genesis of summer time post-midnight EPBs were discussed in light of growth rate of Rayleigh-Taylor instability using SAMI2 model.

  20. Phosphorus flame retardants: properties, production, environmental occurrence, toxicity and analysis.

    PubMed

    van der Veen, Ike; de Boer, Jacob

    2012-08-01

    Since the ban on some brominated flame retardants (BFRs), phosphorus flame retardants (PFRs), which were responsible for 20% of the flame retardant (FR) consumption in 2006 in Europe, are often proposed as alternatives for BFRs. PFRs can be divided in three main groups, inorganic, organic and halogen containing PFRs. Most of the PFRs have a mechanism of action in the solid phase of burning materials (char formation), but some may also be active in the gas phase. Some PFRs are reactive FRs, which means they are chemically bound to a polymer, whereas others are additive and mixed into the polymer. The focus of this report is limited to the PFRs mentioned in the literature as potential substitutes for BFRs. The physico-chemical properties, applications and production volumes of PFRs are given. Non-halogenated PFRs are often used as plasticisers as well. Limited information is available on the occurrence of PFRs in the environment. For triphenyl phosphate (TPhP), tricresylphosphate (TCP), tris(2-chloroethyl)phosphate (TCEP), tris(chloropropyl)phosphate (TCPP), tris(1,3-dichloro-2-propyl)phosphate (TDCPP), and tetrekis(2-chlorethyl)dichloroisopentyldiphosphate (V6) a number of studies have been performed on their occurrence in air, water and sediment, but limited data were found on their occurrence in biota. Concentrations found for these PFRs in air were up to 47 μg m(-3), in sediment levels up to 24 mg kg(-1) were found, and in surface water concentrations up to 379 ng L(-1). In all these matrices TCPP was dominant. Concentrations found in dust were up to 67 mg kg(-1), with TDCPP being the dominant PFR. PFR concentrations reported were often higher than polybrominated diphenylether (PBDE) concentrations, and the human exposure due to PFR concentrations in indoor air appears to be higher than exposure due to PBDE concentrations in indoor air. Only the Cl-containing PFRs are carcinogenic. Other negative human health effects were found for Cl-containing PFRs as well as

  1. Occurrence of springs in massifs of crystalline rocks, northern Portugal

    NASA Astrophysics Data System (ADS)

    Pacheco, Fernando António Leal; Alencoão, Ana Maria Pires

    2002-02-01

    An inventory of artesian springs emerging from fractures (fracture springs) was conducted in the Pinhão River Basin and Morais Massif, northern Portugal, comprising an area of approximately 650 km2. Over 1,500 springs were identified and associated with geological domains and fracture sets. Using cross-tabulation analysis, spring distributions by fracture sets were compared among geological environments, and the deviations related to differences in rock structure and, presumably, to differences in deformational histories. The relation between spring frequencies and rock structures was further investigated by spectral determination, the model introduced in this study. Input data are the spring frequencies and fracture lengths in each geological domain, in addition to the angles between fracture strikes and present-day stress-field orientation (θ). The model's output includes the so-called intrinsic densities, a parameter indexing spring occurrence to factors such as fracture type and associated deformational regime and age. The highest densities (12.2 springs/km of lineament) were associated with young shear fractures produced by brittle deformation, and the lowest (0.1) with old tensional and ductile fractures. Spectral determination also relates each orientation class to a dominant structural parameter: where spring occurrence is controlled by θ, the class is parallel to the present-day stress-field orientation; where the control is attributed to the length of fractures, the spring occurrence follows the strike of large-scale normal faults crossing the region. Résumé. Un inventaire des sources artésiennes émergeant de fractures (sources de fractures) a été réalisé dans le bassin de la rivière Pinhão et dans le massif de Morais, dans le nord du Portugal, dans une région couvrant environ 650 km2. Plus de 1,500 sources ont été identifiées et associées à des domaines géologiques et à des ensembles de fractures. Grâce à une analyse de tableaux

  2. Phosphorus flame retardants: properties, production, environmental occurrence, toxicity and analysis.

    PubMed

    van der Veen, Ike; de Boer, Jacob

    2012-08-01

    Since the ban on some brominated flame retardants (BFRs), phosphorus flame retardants (PFRs), which were responsible for 20% of the flame retardant (FR) consumption in 2006 in Europe, are often proposed as alternatives for BFRs. PFRs can be divided in three main groups, inorganic, organic and halogen containing PFRs. Most of the PFRs have a mechanism of action in the solid phase of burning materials (char formation), but some may also be active in the gas phase. Some PFRs are reactive FRs, which means they are chemically bound to a polymer, whereas others are additive and mixed into the polymer. The focus of this report is limited to the PFRs mentioned in the literature as potential substitutes for BFRs. The physico-chemical properties, applications and production volumes of PFRs are given. Non-halogenated PFRs are often used as plasticisers as well. Limited information is available on the occurrence of PFRs in the environment. For triphenyl phosphate (TPhP), tricresylphosphate (TCP), tris(2-chloroethyl)phosphate (TCEP), tris(chloropropyl)phosphate (TCPP), tris(1,3-dichloro-2-propyl)phosphate (TDCPP), and tetrekis(2-chlorethyl)dichloroisopentyldiphosphate (V6) a number of studies have been performed on their occurrence in air, water and sediment, but limited data were found on their occurrence in biota. Concentrations found for these PFRs in air were up to 47 μg m(-3), in sediment levels up to 24 mg kg(-1) were found, and in surface water concentrations up to 379 ng L(-1). In all these matrices TCPP was dominant. Concentrations found in dust were up to 67 mg kg(-1), with TDCPP being the dominant PFR. PFR concentrations reported were often higher than polybrominated diphenylether (PBDE) concentrations, and the human exposure due to PFR concentrations in indoor air appears to be higher than exposure due to PBDE concentrations in indoor air. Only the Cl-containing PFRs are carcinogenic. Other negative human health effects were found for Cl-containing PFRs as well as

  3. FISH SPECIES OCCURRENCE DENSITIES IN NORTHEASTERN LAKES AND THE EXTENT OF NON-NATIVES

    EPA Science Inventory

    A species' occurrence density is the proportion or number of habitat units (lakes in this case) in a region in which it is present. Reliable estimates of occurrence density should be useful to discussions and decisions about biodiversity, rare species, and non-native invasions. T...

  4. Influence of Dupree diffusivity on the occurrence scattering time advance in turbulent plasmas

    SciTech Connect

    Lee, Myoung-Jae; Jung, Young-Dae

    2015-12-15

    The influence of Dupree diffusivity on the occurrence scattering time advance for the electron-ion collision is investigated in turbulent plasmas. The second-order eikonal method and the effective Dupree potential term associated with the plasma turbulence are employed to obtain the occurrence scattering time as a function of the diffusion coefficient, impact parameter, collision energy, thermal energy, and Debye length. The result shows that the occurrence scattering time advance decreases with an increase of the Dupree diffusivity. Hence, we have found that the influence of plasma turbulence diminishes the occurrence time advance in forward electron-ion collisions in thermal turbulent plasmas. The occurrence time advance shows that the propensity of the occurrence time advance increases with increasing scattering angle. It is also found that the effect of turbulence due to the Dupree diffusivity on the occurrence scattering time advance decreases with an increase of the thermal energy. In addition, the variation of the plasma turbulence on the occurrence scattering time advance due to the plasma parameters is also discussed.

  5. Dyskinetic Movement Disorder among Adults with Mental Retardation: Phenomenology and Co-occurrence with Stereotypy.

    ERIC Educational Resources Information Center

    Bodfish, James W.; And Others

    1996-01-01

    The occurrence of dyskinetic movement disorder and its co-occurrence with stereotypic behavior among adults with mental retardation were studied in 98 adults with mental retardation. Results indicated that stereotypic movement disorder was associated with increased dyskinesia scores and that dyskinesia and stereotypy may be related by common…

  6. Mineral occurrences of New York State with selected references to each locality

    USGS Publications Warehouse

    Luedke, Elaine M.; Wrucke, Chester T.; Graham, John A.

    1959-01-01

    References and locations were compiled for more than 1,000 mineral occurrences in New York State. Each occurrence is shown on an accompanying map and is given by commodity and county in a locality list. Fuels, sand and gravel, and clay are not included in this report.

  7. Geographic selection bias of occurrence data influences transferability of invasive Hydrilla verticillata distribution models

    PubMed Central

    Barnes, Matthew A; Jerde, Christopher L; Wittmann, Marion E; Chadderton, W Lindsay; Ding, Jianqing; Zhang, Jialiang; Purcell, Matthew; Budhathoki, Milan; Lodge, David M

    2014-01-01

    Due to socioeconomic differences, the accuracy and extent of reporting on the occurrence of native species differs among countries, which can impact the performance of species distribution models. We assessed the importance of geographical biases in occurrence data on model performance using Hydrilla verticillata as a case study. We used Maxent to predict potential North American distribution of the aquatic invasive macrophyte based upon training data from its native range. We produced a model using all available native range occurrence data, then explored the change in model performance produced by omitting subsets of training data based on political boundaries. We also compared those results with models trained on data from which a random sample of occurrence data was omitted from across the native range. Although most models accurately predicted the occurrence of H. verticillata in North America (AUC > 0.7600), data omissions influenced model predictions. Omitting data based on political boundaries resulted in larger shifts in model accuracy than omitting randomly selected occurrence data. For well-documented species like H. verticillata, missing records from single countries or ecoregions may minimally influence model predictions, but for species with fewer documented occurrences or poorly understood ranges, geographic biases could misguide predictions. Regardless of focal species, we recommend that future species distribution modeling efforts begin with a reflection on potential spatial biases of available occurrence data. Improved biodiversity surveillance and reporting will provide benefit not only in invaded ranges but also within under-reported and unexplored native ranges. PMID:25360288

  8. The Occurrence and Prevalence of Giraffe Skin Disease in Protected Areas of Northern Tanzania.

    PubMed

    Lee, Derek E; Bond, Monica L

    2016-07-01

    Giraffe skin disease (GSD) is a disorder of undetermined etiology that causes lesions on the forelimbs of Masai giraffe ( Giraffa camelopardalis tippelskirchi). We estimated occurrence and prevalence of GSD in six wildlife conservation areas of Tanzania. The disjunct spatial pattern of occurrence implies that environmental factors may influence GSD. PMID:27310168

  9. The Co-Occurrence of Reading Disorder and ADHD: Epidemiology, Treatment, Psychosocial Impact, and Economic Burden

    ERIC Educational Resources Information Center

    Sexton, Chris C.; Gelhorn, Heather L.; Bell, Jill A.; Classi, Peter M.

    2012-01-01

    The co-occurrence of reading disorder (RD) and attention-deficit/hyperactivity disorder (ADHD) has received increasing attention. This review summarizes the epidemiology, treatment strategies, psychosocial impact, and economic burden associated with the co-occurrence of these conditions. Common genetic and neuropsychological deficits may partially…

  10. Specific Language Impairment in Families: Evidence for Co-Occurrence with Reading Impairments.

    ERIC Educational Resources Information Center

    Flax, Judy F.; Realpe-Bonilla, Teresa; Hirsch, Linda S.; Brzustowicz, Linda M.; Bartlett, Christopher W.; Tallal, Paula

    2003-01-01

    Two family aggregation studies involving 25 children (ages 5-10) with specific language impairment (SLI) report the occurrence and co-occurrence of oral language impairments and reading impairments. Results indicate that when language impairments occur within families of SLI probands, these impairments generally co-occur with reading impairments.…

  11. Occurrence of springs in massifs of crystalline rocks, northern Portugal

    NASA Astrophysics Data System (ADS)

    Pacheco, Fernando António Leal; Alencoão, Ana Maria Pires

    2002-02-01

    An inventory of artesian springs emerging from fractures (fracture springs) was conducted in the Pinhão River Basin and Morais Massif, northern Portugal, comprising an area of approximately 650 km2. Over 1,500 springs were identified and associated with geological domains and fracture sets. Using cross-tabulation analysis, spring distributions by fracture sets were compared among geological environments, and the deviations related to differences in rock structure and, presumably, to differences in deformational histories. The relation between spring frequencies and rock structures was further investigated by spectral determination, the model introduced in this study. Input data are the spring frequencies and fracture lengths in each geological domain, in addition to the angles between fracture strikes and present-day stress-field orientation (θ). The model's output includes the so-called intrinsic densities, a parameter indexing spring occurrence to factors such as fracture type and associated deformational regime and age. The highest densities (12.2 springs/km of lineament) were associated with young shear fractures produced by brittle deformation, and the lowest (0.1) with old tensional and ductile fractures. Spectral determination also relates each orientation class to a dominant structural parameter: where spring occurrence is controlled by θ, the class is parallel to the present-day stress-field orientation; where the control is attributed to the length of fractures, the spring occurrence follows the strike of large-scale normal faults crossing the region. Résumé. Un inventaire des sources artésiennes émergeant de fractures (sources de fractures) a été réalisé dans le bassin de la rivière Pinhão et dans le massif de Morais, dans le nord du Portugal, dans une région couvrant environ 650 km2. Plus de 1,500 sources ont été identifiées et associées à des domaines géologiques et à des ensembles de fractures. Grâce à une analyse de tableaux

  12. Chrysotile: its occurrence and properties as variables controlling biological effects.

    PubMed

    Langer, A M; Nolan, R P

    1994-08-01

    Chrysotile formation arises through serpentinization of ultramafics and silicified dolomitic limestones. Rock types tend to control the trace metal content and both the nature and amounts of admixed minerals in the ore, such as fibrous brucite (nemalite) and tremolite. Some associated minerals and trace metals are thought to play a role in biological potential. Tremolite, one of the important associated minerals, may occur with different morphological forms, called habits. These habits range from asbestiform (tremolite asbestos) to common blocky or non-fibrous form (tremolite cleavage fragments). The latter is most common in nature. Tremolite in chrysotile ore varies in habit and concentration, both factors determining the degree of risk following inhalation. Tremolite fibre is thought to be important in relation to the occurrence of mesothelioma. Chrysotile fibrils may vary in diameter. Dust clouds generated following manipulation vary in fibre number and surface area. Chrysotile fibres exhibit a range of physical characteristics. The fibre may be non-flexible ('stiff') and low in tensile strength ('brittle'), and may lack an ability to curl. This fibre, referred to as 'harsh', sheds water more quickly than its curly, flexible 'soft' variety. The behaviour of the harsh fibres is more amphibole-like and their splintery nature suggests an enhanced inhalation potential. Slip fibre ore from Canada tends to contain more fibrous brucite (nemalite) than cross-fibre ore in the same mine. Industrial manipulation, which includes chemical treatment, heating and milling, may impart new surface properties to chrysotile dusts. Biological potential may be enhanced (opening of fibre bundles) or reduced (disruption of surface bonds and lessened ability to interact with organic moieties). Leaching of magnesium from chrysotile occurs at a pH less than about 10. Chrysotile has been demonstrated to lose magnesium in vivo and undergo clearance from the lung. The biological potential of

  13. PLS Road surface temperature forecast for susceptibility of ice occurrence

    NASA Astrophysics Data System (ADS)

    Marchetti, Mario; Khalifa, Abderrhamen; Bues, Michel

    2014-05-01

    Winter maintenance relies on many operational tools consisting in monitoring atmospheric and pavement physical parameters. Among them, road weather information systems (RWIS) and thermal mapping are mostly used by service in charge of managing infrastructure networks. The Data from RWIS and thermal mapping are considered as inputs for forecasting physical numerical models, commonly in place since the 80s. These numerical models do need an accurate description of the infrastructure, such as pavement layers and sub-layers, along with many meteorological parameters, such as air temperature and global and infrared radiation. The description is sometimes partially known, and meteorological data is only monitored on specific spot. On the other hand, thermal mapping is now an easy, reliable and cost effective way to monitor road surface temperature (RST), and many meteorological parameters all along routes of infrastructure networks, including with a whole fleet of vehicles in the specific cases of roads, or airports. The technique uses infrared thermometry to measure RST and an atmospheric probes for air temperature, relative humidity, wind speed and global radiation, both at a high resolution interval, to identify sections of the road network prone to ice occurrence. However, measurements are time-consuming, and the data from thermal mapping is one input among others to establish the forecast. The idea was to build a reliable forecast on the sole data from thermal mapping. Previous work has established the interest to use principal component analysis (PCA) on the basis of a reduced number of thermal fingerprints. The work presented here is a focus on the use of partial least-square regression (PLS) to build a RST forecast with air temperature measurements. Roads with various environments, weather conditions (clear, cloudy mainly) and seasons were monitored over several months to generate an appropriate number of samples. The study was conducted to determine the minimum

  14. S Gene Mutants Occurrence Among Hepatitis B Carriers in Malaysia

    PubMed Central

    Suppiah, Jeyanthi; Mohd Zain, Rozainanee; Bahari, Norazlah; Haji Nawi, Salbiah; Saat, Zainah

    2014-01-01

    Background: The S gene region of the hepatitis B virus (HBV) codes for surface antigen (HBs Ag) and is responsible for classification of HBV strains. Objectives: The current study aimed to identify important mutations in the S gene in Hepatitis B virus (HBV) isolated from Malaysian HBV carriers. Materials and Methods: Isolated HBV DNAs were subjected for PCR amplification and sequencing of HBV full genome. Results: A total of 76 HBV full genome and 17 partial genome sequences were obtained from the 93 sequenced sera samples Genotyping of the full genome sequences by HEPSEQ software revealed a distribution of 49.46%, 48.39% and 2.15% of genotypes C, B, and D, respectively; whereas phylogenetic and jumping profile Hidden Markov Model (jpHMM) analysis identified six (7.89%) recombinant B/C strains. The distribution of sub-genotypes were B2 (78.79%) and B3 (21.21%) for genotype B, sub genotype D2 (100%) for genotype D and sub genotype C1 (75.76%), C2 (15.15%), C3 (6.06%) and C5 (3.13%) for genotype C. Mutation analysis in the S gene demonstrated two significant mutations which were W182 stop codon and deletion at open reading frame (ORF) of pre-S1 with the frequency occurrence of 2.2% (2/93) and 5.4% (5/93), respectively. The two patients with W182 stop codon were both male, infected with HBV genotype C and one showed progression of liver disease to hepatocellular carcinoma (HCC). Conclusions: Association with sex, genotype and clinical symptoms revealed that the pre-S1 ORF deletion occurred in 40% , 40%,and 20% of genotypes B,C, and D respectively, and 80% of the female population, of which all but one were diagnosed with chronic hepatitis B. Additionally, several mutations were found in the BCP region with the following incidence rate; C1653 T (8.6%), A1752 G (10.8%),1762 AGG--TGA 1764 (26.9%), C1766T(2.2%),T1768 A (10.8%), C1858 T (64.5%), G1896 A (25.8%). PMID:25737728

  15. Occurrence of turbulent flow conditions in supercritical fluid chromatography.

    PubMed

    De Pauw, Ruben; Choikhet, Konstantin; Desmet, Gert; Broeckhoven, Ken

    2014-09-26

    Having similar densities as liquids but with viscosities up to 20 times lower (higher diffusion coefficients), supercritical CO2 is the ideal (co-)solvent for fast and/or highly efficient separations without mass-transfer limitations or excessive column pressure drops. Whereas in liquid chromatography the flow remains laminar in both the packed bed and tubing, except in extreme cases (e.g. in a 75 μm tubing, pure acetonitrile at 5 ml/min), a supercritical fluid can experience a transition from laminar to turbulent flow in more typical operation modes. Due to the significant lower viscosity, this transition for example already occurs at 1.3 ml/min for neat CO2 when using connection tubing with an ID of 127 μm. By calculating the Darcy friction factor, which can be plotted versus the Reynolds number in a so-called Moody chart, typically used in fluid dynamics, higher values are found for stainless steel than PEEK tubing, in agreement with their expected higher surface roughness. As a result turbulent effects are more pronounced when using stainless steel tubing. The higher than expected extra-column pressure drop limits the kinetic performance of supercritical fluid chromatography and complicates the optimization of tubing ID, which is based on a trade-off between extra-column band broadening and pressure drop. One of the most important practical consequences is the non-linear increase in extra-column pressure drop over the tubing downstream of the column which leads to an unexpected increase in average column pressure and mobile phase density, and thus decrease in retention. For close eluting components with a significantly different dependence of retention on density, the selectivity can significantly be affected by this increase in average pressure. In addition, the occurrence of turbulent flow is also observed in the detector cell and connection tubing. This results in a noise-increase by a factor of four when going from laminar to turbulent flow (e.g. going

  16. The Effects of Daily Co-Occurrence of Affect on Older Adults’ Reactivity to Health Stressors

    PubMed Central

    Ramsey, Jennifer L.; Neupert, Shevaun D.; Mroczek, Daniel K.; Spiro, Avron

    2015-01-01

    Objectives The present study examined age differences among older adults in the daily co-occurrence of affect and its potential role in buffering the negative effects of health stressors. Design Participants were from the Veterans Affairs Normative Aging Study (NAS) and included 249 young-old adults (age = 60–79 years, M=71.6) and 64 old-old adults (age = 80–89, M = 82.9) who completed questionnaires assessing stressors, physical health symptoms, and positive and negative affect on eight consecutive days. Results An independent samples t-test showed young-old and old-old adults did not significantly differ in their mean levels of daily co-occurrence of affect. The between-person relationships among stressors, health, and daily co-occurrence of affect revealed that neither stressors nor health were significantly related to daily co-occurrence of affect. However, results from a multilevel model revealed a three-way cross-level interaction (Health Stressor X Age Group X Co-Occurrence of Affect) where old-old adults with higher levels of co-occurrence of affect were less emotionally reactive to health stressors than young-old adults. Conclusion These findings provide support for the assertion that co-occurrence of affect functions in an adaptive capacity and highlight the importance of examining domain specific stressors. PMID:26518259

  17. Occurrence of Metastudtite (Uranium Peroxide Dihydrate) at a FUSRAP Site

    SciTech Connect

    Young, C.M.; Nelson, K.A.; Stevens, G.T.; Grassi, V.J.

    2006-07-01

    Uranium concentrations in groundwater in a localized area of a site exceed the USEPA Maximum Contaminant Level (MCL) by a factor of one thousand. Although the groundwater seepage velocity ranges up to 0.7 meters per day (m/day), data indicate that the uranium is not migrating in groundwater. We believe that the uranium is not mobile because of local geochemical conditions and the unstable nature of the uranium compound present at the site; uranium peroxide dihydrate (metastudtite). Metastudtite [UO{sub 4}.2(H{sub 2}O) or (U(O{sub 2})|O|(OH){sub 2}).3H{sub 2}O] has been identified at other sites as an alteration product in casks of spent nuclear fuel, but neither enriched nor depleted uranium were present at this site. Metastudtite was first identified as a natural mineral in 1983, although documented occurrences in the environment are uncommon. The U.S. Army Corps of Engineers (USACE) is conducting a remedial investigation at the DuPont Chambers Works in Deep water New Jersey under the Formerly Utilized Sites Remedial Action Program (FUSRAP) to evaluate radioactive contamination resulting from historical activities conducted in support of Manhattan Engineering District operations. From 1942 to 1947, Chambers Works converted uranium oxides to uranium tetrafluoride and uranium metal. More than half of the production at this facility resulted from the recovery process, where uranium-bearing dross and scrap were reacted with hydrogen peroxide to produce uranium peroxide dihydrate. The 280-hectare Chambers Works has produced some 600 products, including petrochemicals, aromatics, fluoro-chemicals, polymers, and elastomers. Contaminants resulting from these processes, including separate-phase petrochemicals, have also been detected within the boundaries of the FUSRAP investigation. USACE initiated remedial investigation field activities in 2002. The radionuclides of concern are natural uranium (U{sub nat}) and its short-lived progeny. Areas of impacted soil generally

  18. Human and biophysical influences on fire occurrence in the United States

    USGS Publications Warehouse

    Hawbaker, Todd J.; Radeloff, Volker C.; Stewart, Susan I.; Hammer, Roger B.; Keuler, Nicholas S.; Clayton, Murray K.

    2013-01-01

    National-scale analyses of fire occurrence are needed to prioritize fire policy and management activities across the United States. However, the drivers of national-scale patterns of fire occurrence are not well understood, and how the relative importance of human or biophysical factors varies across the country is unclear. Our research goal was to model the drivers of fire occurrence within ecoregions across the conterminous United States. We used generalized linear models to compare the relative influence of human, vegetation, climate, and topographic variables on fire occurrence in the United States, as measured by MODIS active fire detections collected between 2000 and 2006. We constructed models for all fires and for large fires only and generated predictive maps to quantify fire occurrence probabilities. Areas with high fire occurrence probabilities were widespread in the Southeast, and localized in the Mountain West, particularly in southern California, Arizona, and New Mexico. Probabilities for large-fire occurrence were generally lower, but hot spots existed in the western and south-central United States The probability of fire occurrence is a critical component of fire risk assessments, in addition to vegetation type, fire behavior, and the values at risk. Many of the hot spots we identified have extensive development in the wildland–urban interface and are near large metropolitan areas. Our results demonstrated that human variables were important predictors of both all fires and large fires and frequently exhibited nonlinear relationships. However, vegetation, climate, and topography were also significant variables in most ecoregions. If recent housing growth trends and fire occurrence patterns continue, these areas will continue to challenge policies and management efforts seeking to balance the risks generated by wildfires with the ecological benefits of fire.

  19. Human and biophysical influences on fire occurrence in the United States.

    PubMed

    Hawbaker, Todd J; Radeloff, Volker C; Stewart, Susan I; Hammer, Roger B; Keuler, Nicholas S; Clayton, Murray K

    2013-04-01

    National-scale analyses of fire occurrence are needed to prioritize fire policy and management activities across the United States. However, the drivers of national-scale patterns of fire occurrence are not well understood, and how the relative importance of human or biophysical factors varies across the country is unclear. Our research goal was to model the drivers of fire occurrence within ecoregions across the conterminous United States. We used generalized linear models to compare the relative influence of human, vegetation, climate, and topographic variables on fire occurrence in the United States, as measured by MODIS active fire detections collected between 2000 and 2006. We constructed models for all fires and for large fires only and generated predictive maps to quantify fire occurrence probabilities. Areas with high fire occurrence probabilities were widespread in the Southeast, and localized in the Mountain West, particularly in southern California, Arizona, and New Mexico. Probabilities for large-fire occurrence were generally lower, but hot spots existed in the western and south-central United States The probability of fire occurrence is a critical component of fire risk assessments, in addition to vegetation type, fire behavior, and the values at risk. Many of the hot spots we identified have extensive development in the wildland--urban interface and are near large metropolitan areas. Our results demonstrated that human variables were important predictors of both all fires and large fires and frequently exhibited nonlinear relationships. However, vegetation, climate, and topography were also significant variables in most ecoregions. If recent housing growth trends and fire occurrence patterns continue, these areas will continue to challenge policies and management efforts seeking to balance the risks generated by wildfires with the ecological benefits of fire.

  20. Dispersal strength influences zooplankton co-occurrence patterns in experimental mesocosms.

    PubMed

    Schamp, Brandon S; Arnott, Shelley E; Joslin, Katelyn L

    2015-04-01

    Negative co-occurrence patterns are intriguing because they may reflect the outcome of interspecific interactions and therefore signal how competition shapes communities. However, other factors also contribute to these patterns. For example, theoretical studies as well as two survey-based studies have all suggested that dispersal may also impact these patterns. While natural communities commonly have nonrandom patterns of negative co-occurrence, understanding how different processes drive these patterns requires further research. We tested the influence of dispersal on co-occurrence patterns using a zooplankton mesocosm experiment with four different dispersal treatments varying in the number of dispersers delivered into mesocosms on regular intervals. Our dispersal treatments were intended to adjust the relative importance of dispersal and competition experienced within mesocosms (i.e., high dispersal results in a relatively low influence of competition on species composition and vice versa). Higher dispersal translated into increased zooplankton species richness and inter-mesocosm compositional similarity, and also changed species occupancy patterns such that species occurrences were more even across mesocosms in higher-dispersal treatments. Dispersal treatments also differed markedly in species co-occurrence patterns. Negative co-occurrence patterns were significant for all but the lowest-dispersal treatment, peaked in the intermediate-dispersal treatments, and declined in the highest-dispersal treatment. Stability analyses illustrate that co-occurrence differences are robust to the exclusion of any single mesocosm in null model analyses. Dispersal treatments did not significantly differ with respect to abiotic variation, which has been recognized as a potential driver of negative co-occurrence patterns. These results suggest that not only can dispersal influence patterns of negative co-occurrence via changes to species richness and distribution (occupancy

  1. The occurrence of the freshwater bryozoan Pottsiella erecta (Potts) 1884 (Gymnolaemata: Paludicellidae) in Lake Erie

    USGS Publications Warehouse

    Maciorowski, Anthony F.

    1974-01-01

    The collection of Pottsiella erecta in western Lake Erie in August 1972 represents the first reported occurrence of this species in the Great Lakes and a 110 km northward extension of its known range.

  2. 75 FR 54889 - Draft Guidance for Industry on Suicidality: Prospective Assessment of Occurrence in Clinical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-09

    ... tretinoins, beta blockers (especially those entering the brain), reserpine, drugs for smoking cessation, and... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry on Suicidality: Prospective Assessment of Occurrence in Clinical Trials; Availability AGENCY: Food and Drug Administration, HHS....

  3. A review on cylindrospermopsin: The global occurrence, detection, toxicity and degradation of a potent cyanotoxin

    EPA Science Inventory

    Abstract: Cylindrospermopsin is now recognized as a potent cyanobacterial toxin found in water bodies worldwide. The ever-increasing and global occurrence of massive and prolonged blooms of cylindrospermopsin-producing cyanobacteria in freshwater poses a potential threat to both ...

  4. Distribution and occurrence of total coliform bacteria in Floridan aquifer wells, western Lake County, Florida

    USGS Publications Warehouse

    Taylor, G.F.

    1984-01-01

    Total coliform bacteria data for Floridan aquifer wells in western Lake County, central Florida, are presented. Included are data collected from 1966 to 1979 by the Florida Department of Environmental Regulation for 98 public-supply wells, and data collected during 1982 by the U.S. Geological Survey for 29 wells. The data for the 98 public supplies indicate that 85 percent have a record of total coliform occurrence in the raw water. Data from the 29 wells sampled by the Geological Survey indicate that 55 percent have a record total coliform occurrence. Further comparison of the two data sets indicates that the Geological Survey data generally indicate a lower percentage of sites with coliform occurrence and, in some cases, a different pattern of occurrence than did the Department of Environmental Regulation data. (USGS)

  5. Occurrence of Opportunistic Pathogens Legionella pneumophila and non-tuberculous mycobacteria in hospital plumbing systems

    EPA Science Inventory

    Occurrence of Opportunistic Pathogens Legionella pneumophila and non-tuberculous mycobacteria in hospital plumbing systems Jill Hoelle, Michael Coughlin, Elizabeth Sotkiewicz, Jingrang Lu, Stacy Pfaller, Mark Rodgers, and Hodon Ryu U.S. Environmental Protection Agency, Cincinnati...

  6. Precipitation and the occurrence of lyme disease in the Northeastern United States

    USGS Publications Warehouse

    McCabe, G.J.; Bunnell, J.E.

    2004-01-01

    The occurrence of Lyme disease is a growing concern in the United States, and various studies have been performed to understand the factors related to Lyme disease occurrence. In the United States, Lyme disease has occurred most frequently in the northeastern United States. Positive correlations between the number of cases of Lyme disease reported in the northeastern United States during the 1992-2002 period indicate that late spring/early summer precipitation was a significant climate factor affecting the occurrence of Lyme disease. When late spring/early summer precipitation was greater than average, the occurrence of Lyme disease was above average, possibly due to increased tick activity and survival rate during wet conditions. Temperature did not seem to explain the variability in Lyme disease reports for the northeastern United States. ?? Mary Ann Liebert, Inc.

  7. A Quasi-Metric Approach to Multidimensional Unfolding for Reducing the Occurrence of Degenerate Solutions.

    ERIC Educational Resources Information Center

    Kim, Chulwan; Rangaswamy, Arvind; DeSarbo, Wayne S.

    1999-01-01

    Presents an approach to multidimensional unfolding that reduces the occurrence of degenerate solutions and conducts a Monte Carlo study to demonstrate the superiority of the new method to the ALSCAL and KYST nonmetric procedures for student preference data. (SLD)

  8. A Rare Simultaneous Occurrence of Odontogenic Keratocyst and Unicystic Ameloblastoma in Mandible: A Case Report

    PubMed Central

    Dugal, Arun Govind; Pawar, Sudhir Ramlal; Khandelwal, Saurabh Girish; Iyengar, Apoorva

    2016-01-01

    Odontogenic Keratocyst (OKC) and Ameloblastomas are slow growing benign odontogenic lesions that primarily occur in the molar region of the mandible. Clinically and radiographically both ameloblastoma, especially the Unicystic ameloblastoma and OKC are indistinguishable due to the similar location of occurrence and the age of patients. It is very rare for these lesions to arise simultaneously in a patient’s jaw. The co-occurrence of Ameloblastomas with odontogenic cysts or other odontogenic lesions (histologically in a single lesion)have already been described as combined or hybrid lesions. There are very few reported cases in the English literature for simultaneous occurrence of Unicystic Ameloblastoma and OKC as completely distinct lesions. Here we present such a rare case of the simultaneous occurrence of OKC and ameloblastoma in the posterior region of the mandible of a 22-year-old male in close relation. PMID:27656574

  9. Reported historic asbestos prospects and natural asbestos occurrences in the central United States

    USGS Publications Warehouse

    Van Gosen, Bradley S.

    2006-01-01

    This map and its accompanying dataset provide information for 26 natural asbestos occurrences in the Central United States (U.S.), using descriptions found in the geologic literature. Data on location, mineralogy, geology, and relevant literature for each asbestos site are provided. Using the map and digital data in this report, the user can examine the distribution of previously reported asbestos occurrences and their geological characteristics in the Central U.S. This report is part of an ongoing study by the U.S. Geological Survey to identify and map reported natural asbestos occurrences in the U.S., which began with U.S. Geological Survey Open-File Report 2005-1189 (http://pubs.usgs.gov/of/2005/1189/). These reports are intended to provide State and local government agencies and other stakeholders with geologic information on natural occurrences of asbestos in the U.S.

  10. Diurnal Human Activity and Introduced Species Affect Occurrence of Carnivores in a Human-Dominated Landscape.

    PubMed

    Moreira-Arce, Dario; Vergara, Pablo M; Boutin, Stan

    2015-01-01

    Diurnal human activity and domestic dogs in agro-forestry mosaics should theoretically modify the diurnal habitat use patterns of native carnivores, with these effects being scale-dependent. We combined intensive camera trapping data with Bayesian occurrence probability models to evaluate both diurnal and nocturnal patterns of space use by carnivores in a mosaic of land-use types in southern Chile. A total of eight carnivores species were recorded, including human-introduced dogs. During the day the most frequently detected species were the culpeo fox and the cougar. Conversely, during the night, the kodkod and chilla fox were the most detected species. The best supported models showed that native carnivores responded differently to landscape attributes and dogs depending on both the time of day as well as the spatial scale of landscape attributes. The positive effect of native forest cover at 250 m and 500 m radius buffers was stronger during the night for the Darwin's fox and cougar. Road density at 250 m scale negatively affected the diurnal occurrence of Darwin´s fox, whereas at 500 m scale roads had a stronger negative effect on the diurnal occurrence of Darwin´s foxes and cougars. A positive effect of road density on dog occurrence was evidenced during both night and day. Patch size had a positive effect on cougar occurrence during night whereas it affected negatively the occurrence of culpeo foxes and skunks during day. Dog occurrence had a negative effect on Darwin's fox occurrence during day-time and night-time, whereas its negative effect on the occurrence of cougar was evidenced only during day-time. Carnivore occurrences were not influenced by the proximity to a conservation area. Our results provided support for the hypothesis that diurnal changes to carnivore occurrence were associated with human and dog activity. Landscape planning in our study area should be focused in reducing both the levels of diurnal human activity in native forest remnants

  11. Diurnal Human Activity and Introduced Species Affect Occurrence of Carnivores in a Human-Dominated Landscape

    PubMed Central

    Moreira-Arce, Dario; Vergara, Pablo M.; Boutin, Stan

    2015-01-01

    Diurnal human activity and domestic dogs in agro-forestry mosaics should theoretically modify the diurnal habitat use patterns of native carnivores, with these effects being scale-dependent. We combined intensive camera trapping data with Bayesian occurrence probability models to evaluate both diurnal and nocturnal patterns of space use by carnivores in a mosaic of land-use types in southern Chile. A total of eight carnivores species were recorded, including human-introduced dogs. During the day the most frequently detected species were the culpeo fox and the cougar. Conversely, during the night, the kodkod and chilla fox were the most detected species. The best supported models showed that native carnivores responded differently to landscape attributes and dogs depending on both the time of day as well as the spatial scale of landscape attributes. The positive effect of native forest cover at 250m and 500 m radius buffers was stronger during the night for the Darwin's fox and cougar. Road density at 250m scale negatively affected the diurnal occurrence of Darwin´s fox, whereas at 500m scale roads had a stronger negative effect on the diurnal occurrence of Darwin´s foxes and cougars. A positive effect of road density on dog occurrence was evidenced during both night and day. Patch size had a positive effect on cougar occurrence during night whereas it affected negatively the occurrence of culpeo foxes and skunks during day. Dog occurrence had a negative effect on Darwin's fox occurrence during day-time and night-time, whereas its negative effect on the occurrence of cougar was evidenced only during day-time. Carnivore occurrences were not influenced by the proximity to a conservation area. Our results provided support for the hypothesis that diurnal changes to carnivore occurrence were associated with human and dog activity. Landscape planning in our study area should be focused in reducing both the levels of diurnal human activity in native forest remnants and

  12. Diurnal Human Activity and Introduced Species Affect Occurrence of Carnivores in a Human-Dominated Landscape.

    PubMed

    Moreira-Arce, Dario; Vergara, Pablo M; Boutin, Stan

    2015-01-01

    Diurnal human activity and domestic dogs in agro-forestry mosaics should theoretically modify the diurnal habitat use patterns of native carnivores, with these effects being scale-dependent. We combined intensive camera trapping data with Bayesian occurrence probability models to evaluate both diurnal and nocturnal patterns of space use by carnivores in a mosaic of land-use types in southern Chile. A total of eight carnivores species were recorded, including human-introduced dogs. During the day the most frequently detected species were the culpeo fox and the cougar. Conversely, during the night, the kodkod and chilla fox were the most detected species. The best supported models showed that native carnivores responded differently to landscape attributes and dogs depending on both the time of day as well as the spatial scale of landscape attributes. The positive effect of native forest cover at 250 m and 500 m radius buffers was stronger during the night for the Darwin's fox and cougar. Road density at 250 m scale negatively affected the diurnal occurrence of Darwin´s fox, whereas at 500 m scale roads had a stronger negative effect on the diurnal occurrence of Darwin´s foxes and cougars. A positive effect of road density on dog occurrence was evidenced during both night and day. Patch size had a positive effect on cougar occurrence during night whereas it affected negatively the occurrence of culpeo foxes and skunks during day. Dog occurrence had a negative effect on Darwin's fox occurrence during day-time and night-time, whereas its negative effect on the occurrence of cougar was evidenced only during day-time. Carnivore occurrences were not influenced by the proximity to a conservation area. Our results provided support for the hypothesis that diurnal changes to carnivore occurrence were associated with human and dog activity. Landscape planning in our study area should be focused in reducing both the levels of diurnal human activity in native forest remnants

  13. [COMPARISON OF THE OCCURRENCE RATE OF NAUSEA AND VOMITING AFTER TRANSCUTANEOUS NEPHROLITHOTRIPSY: SEVOFLURANE OR PROPOFOL].

    PubMed

    Ruhd, O A; Naumenko, O V

    2015-05-01

    Impact of various kinds of general anesthesia while performing transcutaneous endoscopic interventions on kidneys on postoperative occurrence and rate of nausea and vomiting were studied. Propofol and sevofluran were used for support of general anesthesia conduction. There was established, that if optimal depth of anesthesia is maintained (bispectral index 40 - 60 units), the rate of nausea and vomiting occurrence do not depend on the kind of anesthesia applied--total intravenous or the inhalation one. PMID:26419041

  14. Occurrences of uranium-bearing minerals in the St. Kevin District, Lake County, Colorado

    USGS Publications Warehouse

    Pierson, C.T.; Singewald, Q.D.

    1953-01-01

    None of the uranium occurrences are of commercial importance. They are for the most part in non-glaciated terrane, which has been subjected to a very long period of weathering.  Thus, chemical leaching within the zone of weathering may have greatly reduced the uranium content of material near the surface, and occurrences of even small quantities of secondary uranium minerals might be related to stronger, primary concentrations at depth.

  15. Modeling Occurrence of Urban Mosquitos Based on Land Use Types and Meteorological Factors in Korea.

    PubMed

    Kwon, Yong-Su; Bae, Mi-Jung; Chung, Namil; Lee, Yeo-Rang; Hwang, Suntae; Kim, Sang-Ae; Choi, Young Jean; Park, Young-Seuk

    2015-10-20

    Mosquitoes are a public health concern because they are vectors of pathogen, which cause human-related diseases. It is well known that the occurrence of mosquitoes is highly influenced by meteorological conditions (e.g., temperature and precipitation) and land use, but there are insufficient studies quantifying their impacts. Therefore, three analytical methods were applied to determine the relationships between urban mosquito occurrence, land use type, and meteorological factors: cluster analysis based on land use types; principal component analysis (PCA) based on mosquito occurrence; and three prediction models, support vector machine (SVM), classification and regression tree (CART), and random forest (RF). We used mosquito data collected at 12 sites from 2011 to 2012. Mosquito abundance was highest from August to September in both years. The monitoring sites were differentiated into three clusters based on differences in land use type such as culture and sport areas, inland water, artificial grasslands, and traffic areas. These clusters were well reflected in PCA ordinations, indicating that mosquito occurrence was highly influenced by land use types. Lastly, the RF represented the highest predictive power for mosquito occurrence and temperature-related factors were the most influential. Our study will contribute to effective control and management of mosquito occurrences.

  16. Factors mediating co-occurrence of an economically valuable introduced fish and its native frog prey.

    PubMed

    Hartman, Rosemary; Pope, Karen; Lawler, Sharon

    2014-06-01

    Habitat characteristics mediate predator-prey coexistence in many ecological systems but are seldom considered in species introductions. When economically important introduced predators are stocked despite known negative impacts on native species, understanding the role of refuges, landscape configurations, and community interactions can inform habitat management plans. We measured these factors in basins with introduced trout (Salmonidae) and the Cascades frog (Rana cascadae) to determine, which are responsible for observed patterns of co-occurrence of this economically important predator and its native prey. Large, vegetated shallows were strongly correlated to co-occurrence, and R. cascadae larvae occur in shallower water when fish are present, presumably to escape predation. The number of nearby breeding sites of R. cascadae was also correlated to co-occurrence, but only when the western toad (Anaxyrus boreas) was present. Because A. boreas larvae are unpalatable to fish and resemble R. cascadae, they may provide protection from trout via Batesian mimicry. Although rescue-effect dispersal from nearby populations may maintain co-occurrence, within-lake factors proved more important for predicting co-occurrence. Learning which factors allow co-occurrence between economically important introduced species and their native prey enables managers to make better-informed stocking decisions. PMID:24372671

  17. Modeling Occurrence of Urban Mosquitos Based on Land Use Types and Meteorological Factors in Korea

    PubMed Central

    Kwon, Yong-Su; Bae, Mi-Jung; Chung, Namil; Lee, Yeo-Rang; Hwang, Suntae; Kim, Sang-Ae; Choi, Young Jean; Park, Young-Seuk

    2015-01-01

    Mosquitoes are a public health concern because they are vectors of pathogen, which cause human-related diseases. It is well known that the occurrence of mosquitoes is highly influenced by meteorological conditions (e.g., temperature and precipitation) and land use, but there are insufficient studies quantifying their impacts. Therefore, three analytical methods were applied to determine the relationships between urban mosquito occurrence, land use type, and meteorological factors: cluster analysis based on land use types; principal component analysis (PCA) based on mosquito occurrence; and three prediction models, support vector machine (SVM), classification and regression tree (CART), and random forest (RF). We used mosquito data collected at 12 sites from 2011 to 2012. Mosquito abundance was highest from August to September in both years. The monitoring sites were differentiated into three clusters based on differences in land use type such as culture and sport areas, inland water, artificial grasslands, and traffic areas. These clusters were well reflected in PCA ordinations, indicating that mosquito occurrence was highly influenced by land use types. Lastly, the RF represented the highest predictive power for mosquito occurrence and temperature-related factors were the most influential. Our study will contribute to effective control and management of mosquito occurrences. PMID:26492260

  18. Factors mediating co-occurrence of an economically valuable introduced fish and its native frog prey.

    PubMed

    Hartman, Rosemary; Pope, Karen; Lawler, Sharon

    2014-06-01

    Habitat characteristics mediate predator-prey coexistence in many ecological systems but are seldom considered in species introductions. When economically important introduced predators are stocked despite known negative impacts on native species, understanding the role of refuges, landscape configurations, and community interactions can inform habitat management plans. We measured these factors in basins with introduced trout (Salmonidae) and the Cascades frog (Rana cascadae) to determine, which are responsible for observed patterns of co-occurrence of this economically important predator and its native prey. Large, vegetated shallows were strongly correlated to co-occurrence, and R. cascadae larvae occur in shallower water when fish are present, presumably to escape predation. The number of nearby breeding sites of R. cascadae was also correlated to co-occurrence, but only when the western toad (Anaxyrus boreas) was present. Because A. boreas larvae are unpalatable to fish and resemble R. cascadae, they may provide protection from trout via Batesian mimicry. Although rescue-effect dispersal from nearby populations may maintain co-occurrence, within-lake factors proved more important for predicting co-occurrence. Learning which factors allow co-occurrence between economically important introduced species and their native prey enables managers to make better-informed stocking decisions.

  19. Palynomorph - based palaeoenvironmental inferences of the Shemshak Formation, at the Khoshyeilagh section, northeastern Shahrud

    NASA Astrophysics Data System (ADS)

    Sajjadi, F.; Ghasemi Nejad, E.; Hakimi Tehrani, Z.

    2009-04-01

    The palaeoenvironment of the Shemshak Formation at the Khoshyeilagh section north of Ghoznavi Village was studied by using palynomorphs and organic matter contents. A total of 67 samples were collected and prepared palynologically from the formation. Diverse and reasonably well preserved palynomorphs are recorded. This section with 1280 m thickness is consists of shale, sandatone and coal layer. The palynologically productive samples contain spores, pollen grains, dark and transparent AOM, opaque phytoclasts, phytoplankton (dinofelagellate cysts), woody debris (plant tissue) which were studied statistically. The high abundance of terrestrial palynomorphs dominating phytoclasts indicates accumulation in a deltaic environment. However, occurrence of marine palynomorphs testifies intermittent marine incursions. Keywords: Shemshak Formation, Palynomorphs, Khoshyeilagh, Palaeoenvironment, Shahrud.

  20. Jurassic onychites (hooks from squid-like cephalopods) associated with statolith occurrences in the Wessex Basin, southern England

    NASA Astrophysics Data System (ADS)

    Hart, Malcolm; Page, Kevin; Price, Gregory; Smart, Christopher; Wilby, Philip

    2016-04-01

    , A., PAGE, K.N., PRICE, G.D. & SMART, C.W. (in press). Exceptional accumulations of statoliths in association with the Christian Malford lagerstätte (Callovian, Jurassic) in Wiltshire, United Kingdom. Palaios. KULICKI, C. & SZANIAWSKI, H. 1972. Cephalopod arm hooks from the Jurassic of Poland. Acta Palaeontologica Polonica, 17, 379-419. WILBY, P.R., HUDSON, J.D., CLEMENTS, R.G. & HOLLINGWORTH, N.T.J. 2004. Taphonomy and origin of an accumulate of soft-bodied cephalopods in the Oxford Clay Formation (Jurassic, England). Palaeontology, 47, 1159-1180. WILBY, P.R., DUFF, K., PAGE, K. & MARTIN, S. 2008. Preserving the unpreservable: a lost world discovered at Christian Malford, UK. Geology Today, 24(3), 95-98.