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Sample records for profiles beneath native

  1. Estimates of deep percolation beneath native vegetation, irrigated fields, and the Amargosa-River Channel, Amargosa Desert, Nye County, Nevada

    Science.gov (United States)

    Stonestrom, David A.; Prudic, David E.; Laczniak, Randell J.; Akstin, Katherine C.; Boyd, Robert A.; Henkelman, Katherine K.

    2003-01-01

    The presence and approximate rates of deep percolation beneath areas of native vegetation, irrigated fields, and the Amargosa-River channel in the Amargosa Desert of southern Nevada were evaluated using the chloride mass-balance method and inferred downward velocities of chloride and nitrate peaks. Estimates of deep-percolation rates in the Amargosa Desert are needed for the analysis of regional ground-water flow and transport. An understanding of regional flow patterns is important because ground water originating on the Nevada Test Site may pass through the area before discharging from springs at lower elevations in the Amargosa Desert and in Death Valley. Nine boreholes 10 to 16 meters deep were cored nearly continuously using a hollow-stem auger designed for gravelly sediments. Two boreholes were drilled in each of three irrigated fields in the Amargosa-Farms area, two in the Amargosa-River channel, and one in an undisturbed area of native vegetation. Data from previously cored boreholes beneath undisturbed, native vegetation were compared with the new data to further assess deep percolation under current climatic conditions and provide information on spatial variability. The profiles beneath native vegetation were characterized by large amounts of accumulated chloride just below the root zone with almost no further accumulation at greater depths. This pattern is typical of profiles beneath interfluvial areas in arid alluvial basins of the southwestern United States, where salts have been accumulating since the end of the Pleistocene. The profiles beneath irrigated fields and the Amargosa-River channel contained more than twice the volume of water compared to profiles beneath native vegetation, consistent with active deep percolation beneath these sites. Chloride profiles beneath two older fields (cultivated since the 1960?s) as well as the upstream Amargosa-River site were indicative of long-term, quasi-steady deep percolation. Chloride profiles beneath the

  2. Profile: Native Hawaiians and Pacific Islanders

    Science.gov (United States)

    ... cancer, heart disease, unintentional injuries (accidents), stroke and diabetes. Some other health conditions and risk factors that are prevalent among Native Hawaiians/Pacific Islanders are hepatitis B, HIV/AIDS, and tuberculosis. Other Health Concerns: It is significant to note ...

  3. Stream bed temperature profiles as indicators of percolation characteristics beneath arroyos in the middle Rio Grande Basin, USA

    Science.gov (United States)

    Constantz, J.; Thomas, C.L.

    1997-01-01

    Stream bed temperature profiles were monitored continuously during water year 1990 and 1991 (WY90 and 91) in two New Mexico arroyos, similar in their meteorological features and dissimilar in their hydrological features. Stream bed temperature profiles between depths of 30 and 300 cm were examined to determine whether temporal changes in temperature profiles represent accurate indicators of the timing, depth and duration of percolation in each stream bed. These results were compared with stream flow, air temperature, and precipitation records for WY90 and 91, to evaluate the effect of changing surface conditions on temperature profiles. Temperature profiles indicate a persistently high thermal gradient with depth beneath Grantline Arroyo, except during a semi-annual thermal reversal in spring and autumn. This typifies the thermal response of dry sediments with low thermal conductivities. High thermal gradients were disrupted only during infrequent stream flows, followed by rapid re-establishment of high gradients. The stream bed temperature at 300 cm was unresponsive to individual precipitation or stream flow during WY90 and 91. This thermal pattern provides strong evidence that most seepage into Grantline Arroyo failed to percolate at a sufficient rate to reach 300 cm before being returned to the atmosphere. A distinctly different thermal pattern was recorded beneath Tijeras Arroyo. Low thermal gradients between 30 and 300 cm and large diurnal variations in temperature, suggest that stream flow created continuous, advection-dominated heat transport for over 300 days, annually. Beneath Tijeras Arroyo, low thermal gradients were interrupted only briefly during periodic, dry summer conditions. Comparisons of stream flow records for WY90 and 91 with stream bed temperature profiles indicate that independent analysis of thermal patterns provides accurate estimates of the timing, depth and duration of percolation beneath both arroyos. Stream flow loss estimates indicate

  4. Sodium storage in deep paleoweathering profiles beneath the Paleozoic-Triassic unconformity

    Science.gov (United States)

    Thiry, M.; Parcerisa, D.; Ricordel-Prognon, C.; Schmitt, J.-M.

    2009-04-01

    pink stage, with an increase in the amount and size of sericite and hematite inclusions. The latter causes the red coloration of the altered rocks. Regional layout Regional distribution of the alterations which affect the Carboniferous igneous and volcanic formations beneath the Jurassic sedimentary cover lead to associate these alterations to the Triassic unconformity. Besides, albitized facies show generally both topographic and regional arrangements, with more altered facies occurring in the mountain highs and in the external parts of the massifs and unaltered facies occurring in the river valleys and in the central parts of the massifs. Moreover, the haematite associated with these albitized basement rocks has been dated from Early Trias by means of paleomagnetism (Ricordel et al, 2007). From this layout and dating, it is deduced that albitization is related to the development of a deep weathering profile (up to 150 m deep) during a long-lasting exposure of the Triassic erosional unconformity (regolith). Geochemistry and paleoenvironmental setting It has to be highlighted that, this alteration may not behave like an "ordinary" weathering profile and occurred under unusual, or at least very specific, geological settings. The scale of the profiles (over 100 m depth) relates this alteration rather to a groundwater environment. The weak mobility of most chemical elements may point to a groundwater with very low outflows and deep water table. This may occur in very subdued landscape and in arid climatic conditions. It has also to be pointed that this alteration may have lasted for several 10's of Ma. Albite formation at low temperature may be envisioned consequently in alkaline, confined waters with sufficient concentrations of sodium and silica. Early attempts of modeling (Schmitt, 1994) have also indicated that a high Na+/K+ ratio is as well probably required. Petrographic data also indicate an import of sodium by the weathering solutions, without any clear enrichment

  5. Socioeconomic profiles of native American communities: Duckwater Shoshone Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Hamby, M. [Cultural Resources Consultants Ltd., Reno, NV (United States)

    1991-10-01

    This report presents socioeconomic aspects of Native Americans of the Duckwater Shoshone Reservation. A survey is included concerning their views on the proposed Yucca Mountain waste repository. (CBS)

  6. Socioeconomic profiles of native American communities: Yomba Shoshone Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Hamby, M.; Rusco, E. [Cultural Resources Consultants Ltd., Reno, NV (United States)

    1991-10-01

    This report was written by the State of Nevada Agency for Nuclear Projects/Nuclear Waste Project Office. This office oversees the nuclear waste activities for the proposed Yucca Mountain high-level waste facility for the state of Nevada. The Yomba Shoshone Reservation socio-economic profile was the basis of this paper. It describes the life and current status of the Shoshone Indians. Population, utilities, education and social services of the Shoshone are examples of the topics which are discussed. It is intended as base-line information only. It eventually summarizes and compares data from the public opinion of the Shoshone about the high level waste repository at Yucca Mountain. (MB)

  7. Oilseeds native to the Cerrado have fatty acid profile beneficial for cardiovascular health

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    Aline Medeiros ALVES

    Full Text Available ABSTRACT Objective: To assess and compare the fatty acid composition of edible seeds and a nut native to the Cerrado (Brazilian savannah to that of traditional oilseeds. Methods: Baru almonds, Cerrado cashew nuts, and pequi almonds were extracted from the fruits using appropriate equipment. All edible seeds and nuts were roasted, except for the Brazil nut. The sample lipids were extracted via cold pressing. The fatty acids were esterified, and the fatty acid esters were analyzed by gas chromatography. Results: The native and traditional edible seeds and nuts contain mostly monounsaturated fatty acids (42.72 g to 63.44 g/100 g, except for the Brazil nut, which showed predominance of polyunsaturated fatty acids (45.48 g/100 g. Pequi almond had the highest saturated fatty acid content (36.14 g/100 g. The fatty acids with the highest concentration were oleic and linoleic acids, and palmitic acid was also found in considerable concentration in the oilseeds studied. The Cerrado cashew nut and the traditional cashew nut have similar fatty acid profiles. As for the ratio of ω-6 to ω-3, the baru almond showed the highest ratio, 9:1, which was the closest to the recommended intake of these fatty acids. Conclusion: The fatty acid profile of the edible seeds and nuts native to the cerrado is similar to those of traditional oilseeds. We suggest the inclusion of native oilseeds in the diet aiming at reducing the risk of cardiovascular disease, especially the baru almond and the cerrado cashew nut, due to the fact they have high ratio of monounsaturated fatty acids to saturated fatty acids.

  8. Comparative gene expression profile analysis between native human odontoblasts and pulp tissue.

    Science.gov (United States)

    Pääkkönen, V; Vuoristo, J T; Salo, T; Tjäderhane, L

    2008-02-01

    To undertake a large-scale analysis of the expression profiles of native human pulp tissue and odontoblasts, and search for genes expressed only in odontoblasts. Microarray was performed to pooled pulp and odontoblasts of native human third molars and to pooled +/- TGF-beta1 cultured pulps and odontoblasts (137 teeth). The repeatability of microarray analysis was estimated by comparing the experimental pulp samples with expression profiles of two pulp samples downloaded from the GEO database. The genes expressed only in the experimental pulp samples or in odontoblasts were divided into categories, and the expression of selected odontoblast-specific genes of extracellular matrix (ECM) organization and biogenesis category was confirmed with RT-PCR and Western blot. A 85.3% repeatability was observed between pulp microarrays, demonstrating the high reliability of the technique. Overall 1595 probe sets were positive only in pulp and 904 only in odontoblasts. Sixteen expressed sequence tags (ESTs), which represent transcribed sequences encoding possibly unknown genes, were detected only in odontoblasts; two consistently expressed in all odontoblast samples. Matrilin 4 (MATN4) was the only ECM biogenesis and organization related gene detected in odontoblasts but not in pulp by microarray and RT-PCR. MATN4 protein expression only in odontoblasts was confirmed by Western blot. Pulp tissue and odontoblast gene expression profiling provides basic data for further, more detailed protein analysis. In addition, MATN4 and the two ESTs could serve as an odontoblast differentiation marker, e.g. in odontoblast stem cell research.

  9. Non-native english speaking elementary ell teachers’ culturally responsive leadership profile in an ESL context

    Directory of Open Access Journals (Sweden)

    Valentin Ekiaka Nzai

    2012-12-01

    Full Text Available Culturally responsive instruction has been suggested as quality education (Edwards, 2003 for minority students in subtractive and additivebilingualism settings. However, analytical curriculum development of several official English programs revealed that the gender-centric (malecentricand Ethno-centric (Euro/Western-centric approaches were deeply embedded in most English textbooks of curriculum development.The intent of partial mixed methods paper consisted of exploring some non-native English speaking teachers English teachers’ culturallyresponsive leadership profile in order to further the discussion on not only how to promote English curriculum transformation in English assecond language (ESL and English as foreign language (EFL settings, but also to effectively train culturally responsive non-native Englishspeaking (NNES English pre-service teachers. Comparative data analysis suggested that there were no causal relationship between NNESEnglish teachers’ culturally responsive leadership styles and their abilities to perform multicultural transformation of English curriculums. To behighly effective in transforming English curriculum, NNES English teachers needed to be systematically trained on how to do so. Implicationsfor NNES English pre-service teacher education are framed from the culturally responsive and anti-oppressive education approaches.

  10. Relationships between seismic wave-Speed, density, and electrical conductivity beneath Australia from seismology, mineralogy, and laboratory-based conductivity profiles

    DEFF Research Database (Denmark)

    Khan, A.; Koch, S.; Shankland, T. J.

    2015-01-01

    We present maps of the three-dimensional density (ρ), electrical conductivity (σ), and shear-wave speed (VS) structure of the mantle beneath Australia and surrounding ocean in the depth range of 100–800 km. These maps derived from stochastic inversion of seismic surface-wave dispersion data, ther...

  11. Digital natives and academics libraries: a parallel between the new user profile and products and services information

    Directory of Open Access Journals (Sweden)

    Thais Batista Zaninelli

    2016-12-01

    Full Text Available Introduction: the purpose of this paper is to analyze how the digital natives can influence the information services in the University Libraries (ULs context. Objective: the objectives were to characterize the digital natives; to check the current format of the university libraries with respect to infrastructure, service and staff; to analyze how the characteristics of digital natives may influence future library services. Methodology: bibliographic search. Results: current users of the ULs, are categorized in the context of digital natives. This type of users is characterized by having a contemporary profile, basically communicate virtually, search online form and information in digital form, but at the same time looking for alternative and collaborative environments to carry out their academic activities in physical spaces. These users prefer to meet in alternative schedules and aspire services that meet their needs not only informational but also leisure. Conclusions: it is noticed that the ULs are ahead when it comes to achieving not only the information needs of digital natives users, but also to realize their wishes for the consumption of information. Many libraries now offer collaborative study spaces, in addition to individual, vertical establish partnerships with IT companies and cultural centers in order to meet the current needs of the digital generation.

  12. Protein Profile in Corpus Luteum during Pregnancy in Korean Native Cows

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    H. J. Chung

    2012-11-01

    Full Text Available Steroidogenesis requires coordination of the anabolic and catabolic pathways of lipid metabolism, but the profile of proteins associated with progesterone synthesis in cyclic and pregnant corpus luteum (CL is not well-known in cattle. In Experiment 1, plasma progesterone level was monitored in cyclic cows (n = 5 and pregnant cows (n = 6; until d-90. A significant decline in the plasma progesterone level occurred at d-19 of cyclic cows. Progesterone level in abbatoir-derived luteal tissues was also determined at d 1 to 5, 6 to 13 and 14 to 20 of cyclic cows, and d-60 and -90 of pregnant cows (n = 5 each. Progesterone level in d-60 CL was not different from those in d 6 to 13 CL and d-90 CL, although the difference between d 6 to 13 and d-90 was significant. In Experiment 2, protein expression pattern in CL at d-90 (n = 4 was compared with that in CL of cyclic cows at d 6 to 13 (n = 5. Significant changes in the level of protein expression were detected in 32 protein spots by two-dimensional polyacrylamide gel electrophoresis (2-DE, and 23 of them were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS. Six proteins were found only in pregnant CL, while the other 17 proteins were found only in cyclic CL. Among the above 6 proteins, vimentin which is involved in the regulation of post-implantation development was included. Thus, the protein expression pattern in CL was disorientated from cyclic luteal phase to mid pregnancy, and alterations in specific CL protein expression may contribute to the maintenance of pregnancy in Korean native cows.

  13. Neuroanatomical profiles of deafness in the context of native language experience.

    Science.gov (United States)

    Olulade, Olumide A; Koo, Daniel S; LaSasso, Carol J; Eden, Guinevere F

    2014-04-16

    The study of congenitally deaf adult humans provides an opportunity to examine neuroanatomical plasticity resulting from altered sensory experience. However, attributing the source of the brain's structural variance in the deaf is complicated by the fact that deaf individuals also differ in their language experiences (e.g., sign vs spoken), which likely influence brain anatomy independently. Although the majority of deaf individuals in the United States are born to hearing parents and are exposed to English, not American Sign Language (ASL) as their first language, most studies on deafness have been conducted with deaf native users of ASL (deaf signers). This raises the question of whether observations made in deaf signers can be generalized. Using a factorial design, we compared gray (GMV) and white (WMV) matter volume in deaf and hearing native users of ASL, as well as deaf and hearing native users of English. Main effects analysis of sensory experience revealed less GMV in the deaf groups combined (compared with hearing groups combined) in early visual areas and less WMV in a left early auditory region. The interaction of sensory experience and language experience revealed that deaf native users of English had fewer areas of anatomical differences than did deaf native users of ASL (each compared with their hearing counterparts). For deaf users of ASL specifically, WMV differences resided in language areas such as the left superior temporal and inferior frontal regions. Our results demonstrate that cortical plasticity resulting from deafness depends on language experience and that findings from native signers cannot be generalized.

  14. Profiling the “native speaker” of English: myths and implications for ...

    African Journals Online (AJOL)

    It shows that many of the common assumptions are either hollow, half-truths or are deliberately intended to reinforce social, political, economic and educational exclusivity. The article then goes on to show how the notion of the “native speaker” of English affects ESL teaching and learning. In each case, it is argued that an ...

  15. SAGE III Meteor-3M L2 Solar Event Species Profiles (Native) V004

    Data.gov (United States)

    National Aeronautics and Space Administration — SAGE III Meteor-3M L2 Solar Event Species Profiles are Level 2 data files containing all the species products for a single solar event. The Stratospheric Aerosol and...

  16. SAGE III Meteor-3M L2 Lunar Event Species Profiles (Native) V003

    Data.gov (United States)

    National Aeronautics and Space Administration — SAGE III Meteor-3M L2 Lunar Event Species Profiles are Level 2 data files containing all the species products for a single lunar event. The Stratospheric Aerosol and...

  17. Imaging voids beneath bridge bent using electrical resistivity tomography.

    Science.gov (United States)

    2014-02-01

    Five electrical resistivity tomography (ERT) profiles and borehole control were acquired beneath two bridges on the bank of the : Gasconade River in order to determine extension of the underground water-filled openings in rock encountered during a dr...

  18. The Wildcat Corpus of native- and foreign-accented English: communicative efficiency across conversational dyads with varying language alignment profiles.

    Science.gov (United States)

    Van Engen, Kristin J; Baese-Berk, Melissa; Baker, Rachel E; Choi, Arim; Kim, Midam; Bradlow, Ann R

    2010-01-01

    This paper describes the development of the Wildcat Corpus of native- and foreign-accented English,a corpus containing scripted and spontaneous speech recordings from 24 native speakers of American English and 52 non-native speakers of English.The core element of this corpus is a set of spontaneous speech recordings, for which a new method of eliciting dialogue-based, laboratory-quality speech recordings was developed (the Diapix task). Dialogues between two native speakers of English, between two non-native speakers of English (with either shared or different LIs), and between one native and one non-native speaker of English are included and analyzed in terms of general measures of communicative efficiency.The overall finding was that pairs of native talkers were most efficient, followed by mixed native/non-native pairs and non-native pairs with shared LI. Non-native pairs with different LIs were least efficient.These results support the hypothesis that successful speech communication depends both on the alignment of talkers to the target language and on the alignment of talkers to one another in terms of native language background.

  19. Insights into plant cell wall structure, architecture, and integrity using glycome profiling of native and AFEXTM-pre-treated biomass.

    Science.gov (United States)

    Pattathil, Sivakumar; Hahn, Michael G; Dale, Bruce E; Chundawat, Shishir P S

    2015-07-01

    Cell walls, which constitute the bulk of plant biomass, vary considerably in their structure, composition, and architecture. Studies on plant cell walls can be conducted on both native and pre-treated plant biomass samples, allowing an enhanced understanding of these structural and compositional variations. Here glycome profiling was employed to determine the relative abundance of matrix polysaccharides in several phylogenetically distinct native and pre-treated plant biomasses. Eight distinct biomass types belonging to four different subgroups (i.e. monocot grasses, woody dicots, herbaceous dicots, and softwoods) were subjected to various regimes of AFEX™ (ammonia fiber expansion) pre-treatment [AFEX is a trademark of MBI, Lansing (http://www.mbi.org]. This approach allowed detailed analysis of close to 200 cell wall glycan epitopes and their relative extractability using a high-throughput platform. In general, irrespective of the phylogenetic origin, AFEX™ pre-treatment appeared to cause loosening and improved accessibility of various xylan epitope subclasses in most plant biomass materials studied. For most biomass types analysed, such loosening was also evident for other major non-cellulosic components including subclasses of pectin and xyloglucan epitopes. The studies also demonstrate that AFEX™ pre-treatment significantly reduced cell wall recalcitrance among diverse phylogenies (except softwoods) by inducing structural modifications to polysaccharides that were not detectable by conventional gross composition analyses. It was found that monitoring changes in cell wall glycan compositions and their relative extractability for untreated and pre-treated plant biomass can provide an improved understanding of variations in structure and composition of plant cell walls and delineate the role(s) of matrix polysaccharides in cell wall recalcitrance. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  20. Stroke and Native Hawaiians/Pacific Islanders

    Science.gov (United States)

    ... Population Profiles > Native Hawaiian/Other Pacific Islander > Stroke Stroke and Native Hawaiians/Pacific Islanders Native Hawaiians/Pacific ... non-Hispanic white adults to die from a stroke in 2010. In general, Native Hawaiian/Pacific Islander ...

  1. Beneath our Feet

    Science.gov (United States)

    Vernon, Ron

    2001-01-01

    How much do you know about the rocks beneath your feet--the basic materials of our planet? Their variety and beauty is astounding, especially when viewed through the microscope, where crystals of different minerals and in various arrangements are revealed in exquisite detail. While surface rocks seem so solid, they flow deep inside the earth, and, in this spectacular book, you'll see what rocks that have flowed actually look like. Eminent geologist Ron Vernon reveals the incredible beauty and variety of earth rocks, both under and on the surface. Through breathtaking photographs he captures rocks formed by heating and melting inside the earth, rocks ejected from volcanoes, rocks formed by erosion on the earth's surface, and extraterrestrial rocks that have crashed into our planet. These stunning images are accompanied by clear, nontechnical explanations of the processes underlying the creation of rocks and minerals. No other current book so cogently explains the nature and origin of rocks for nonscientists. Beneath Our Feet: The Rocks of Planet Earth is destined to be a must-have purchase for a wide-ranging audience from professional scientists to amateur rock collectors--indeed anyone interested in natural history.

  2. Mapping crustal thinning beneath the Eastern Pyrenees

    Science.gov (United States)

    Diaz, Jordi; Chevrot, Sebastien; Verges, Jaume; Sylvander, Matthieu; Ruiz, Mario; Antonio-Vigil, Amanda

    2017-04-01

    The eastern termination of the Pyrenees is a complex region marked by two large tectonic events, the building of the Pyrenees during the Alpine orogeny and the Neogene extensional processes associated to the rotation of the Sardinia-Corsica block and the opening of the Valencia Trough. This complex tectonic history has left major imprints in crustal structures. Previous studies based on gravity data and active seismic profiles have documented a crustal thinning from 40-45 km about 80 km to the west of the Mediterranean coastline to less than 25 km beneath the eastern termination of the Pyrenees. To progress in the knowledge of the geometry of this transition, two passive seismic profiles have been acquired from mid 2015 to late 2016 within the OROGEN project, an academic-industrial collaboration between CNRS-Total-BRGM and CSIC. Up to 38 broad-band stations were deployed along two orthogonal lines, with an interstation spacing close to 10 km. First results of receiver function migration on the E-W profile suggest a smooth Moho thinning smoothly from 40 km beneath the western termination of the line to 23 km close to the coastline. The NNE-SSW profile shows a clearly defined Moho beneath Iberia, slightly deepening from 32 to 35 km northwards, a 28-30 km thick crust underneath the North Pyrenean Front Thrust and a complex geometry in the Axial Zone. Data from natural events located in the Gulf of Roses and near the intersecting point of the profiles have been recorded along the lines, hence allowing to produce wide angle reflection/refraction profiles providing additional constraints on the geometry of the crust/mantle boundary in the Eastern Pyrenees. These new results will be integrated with the available geophysical and geologic information for a more accurate geodynamical interpretation of the results. (Additional founding by the MISTERIOS project, CGL2013-48601-C2-1-R)

  3. Effect of balanced concentrate ration on the performance and hematobiochemical profile of lactating native ewes and lambs in coastal Odisha

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    Sasanka Sekhar Beura

    2014-12-01

    Full Text Available Aim: The present study was conducted to evaluate the effect of supplementation of balanced concentrate ration during lactation on the growth performance, blood and metabolic profiles of native ewes and lambs in coastal Odisha. Materials and Methods: A total of 40 numbers of lactating ewes of the same parity comprised the experimental animals. The selected ewes were randomly assigned to two groups of twenty each, maintaining uniformity in body weight (13.36±0.33 kg for Group 1 and 13.48±0.37 kg for Group 2. Group 1 was maintained on grazing only while Group 2 was supplemented with a balanced concentrate mixture @ 200 g/head/day during the first 2 months of lactation. The concentrate was fed individually in separate containers in the morning hours before the animals were taken out for grazing. Results: The ewes in Group 2 registered higher body weights at every fortnight. The differences were found to be highly significant (p<0.01 from 2nd to 5th fortnight and significant (p<0.05 for the remaining fortnights. The ewes in Group 2 showed significantly (p<0.01 higher daily gains than those in Group 1 at every fortnight. The hemoglobin (Hb concentration, mean cell hemoglobin (MCH and total leukocyte count (TLC values were significant (p<0.05 between groups at the end of 4th fortnight after lambing and the mean cell hemoglobin concentration (MCHC values is significantly (p<0.05 higher in Group 2 over Group 1. Conclusion: It was concluded that supplementation of a balanced concentrate mixture (crude protein 18.21% @ 200 g/ewe/day along with grazing during the first 2 months of lactation resulted in higher ewe body weight gain. It improved their hematological and metabolic profiles and also resulted in higher body weight gain in lambs born to these supplemented ewes.

  4. General expression profiles of human native odontoblasts and pulp-derived cultured odontoblast-like cells are similar but reveal differential neuropeptide expression levels.

    Science.gov (United States)

    Pääkkönen, Virve; Bleicher, Françoise; Carrouel, Florence; Vuoristo, Jussi T; Salo, Tuula; Wappler, Ilka; Couble, Marie-Lise; Magloire, Henry; Peters, Heiko; Tjäderhane, Leo

    2009-01-01

    Odontoblasts play a central role during the dentin formation by organic matrix production and mineralisation. Recently, suitable in vitro techniques for studying mature primary odontoblasts and the newly differentiated odontoblasts have been developed. Firstly, the gene expression profiles of native and cultured odontoblasts were compared at large-scale to investigate the similarities and differences between the samples. Secondly, differential expression levels of the genes encoding neuronal proteins were analyzed to study odontoblasts sensory function. Microarray analysis was performed to mature native and cultured pulp-derived odontoblast-like cells to compare their transcriptome. Then, the probes positive only in one sample were divided into gene ontology categories. Expression levels of selected neuronal proteins were further studied with quantitative PCR, and at the protein level by immunofluorescence of mature and newly differentiated odontoblasts in developing tooth. Remarkable similarities between the general and neuronal protein gene expression profiles were observed. Higher cortistatin, galanin, somatostatin receptor 1 (SSTR1) and tyrosine phosphatase receptor type Z1 (PTPRZ1) expression was detected in native than in cultured odontoblast at the mRNA level. Pronociceptin was more abundantly expressed in cultured than in native odontoblasts. Immunofluorescence of mature and newly differentiated odontoblasts on human tooth germs confirmed the results. Cultured odontoblasts used in this study have similar general gene expression pattern to native odontoblasts, and therefore offer a valuable tool for the in vitro odontoblast studies. The expression of PTPRZ1 and galanin, which participate in sensory signal transduction, supports the previously suggested role of odontoblasts as sensory cells.

  5. Obesity and Native Hawaiians/Pacific Islanders

    Science.gov (United States)

    ... Population Profiles > Native Hawaiian/Other Pacific Islander > Obesity Obesity and Native Hawaiians/Pacific Islanders Native Hawaiians/Pacific ... youthonline . [Accessed 08/18/2017] HEALTH IMPACT OF OBESITY People who are overweight are more likely to ...

  6. Comparative expression profile of NOD1/2 and certain acute inflammatory cytokines in thermal-stressed cell culture model of native and crossbred cattle

    Science.gov (United States)

    Bhanuprakash, V.; Singh, Umesh; Sengar, Gyanendra Singh; Raja, T. V.; Sajjanar, Basavraj; Alex, Rani; Kumar, Sushil; Alyethodi, R. R.; Kumar, Ashish; Sharma, Ankur; Kumar, Suresh; Bhusan, Bharat; Deb, Rajib

    2017-05-01

    Thermotolerance depends mainly on the health and immune status of the animals. The variation in the immune status of the animals may alter the level of tolerance of animals exposed to heat or cold stress. The present study was conducted to investigate the expression profile of two important nucleotide binding and oligomerization domain receptors (NLRs) (NOD1 and NOD2) and their central signalling molecule RIP2 gene during in vitro thermal-stressed bovine peripheral blood mononuclear cells (PBMCs) of native (Sahiwal) and crossbred (Sahiwal X HF) cattle. We also examined the differential expression profile of certain acute inflammatory cytokines in in vitro thermal-stressed PBMC culture among native and its crossbred counterparts. Results revealed that the expression profile of NOD1/2 positively correlates with the thermal stress, signalling molecule and cytokines. Present findings also highlighted that the expression patterns during thermal stress were comparatively superior among indigenous compared to crossbred cattle which may add references regarding the better immune adaptability of Zebu cattle.

  7. Appropriately differentiated ARPE-19 cells regain phenotype and gene expression profiles similar to those of native RPE cells.

    Science.gov (United States)

    Samuel, William; Jaworski, Cynthia; Postnikova, Olga A; Kutty, R Krishnan; Duncan, Todd; Tan, Li Xuan; Poliakov, Eugenia; Lakkaraju, Aparna; Redmond, T Michael

    2017-01-01

    The RPE cell line ARPE-19 provides a dependable and widely used alternative to native RPE. However, replication of the native RPE phenotype becomes more difficult because these cells lose their specialized phenotype after multiple passages. Compounding this problem is the widespread use of ARPE-19 cells in an undifferentiated state to attempt to model RPE functions. We wished to determine whether suitable culture conditions and differentiation could restore the RPE-appropriate expression of genes and proteins to ARPE-19, along with a functional and morphological phenotype resembling native RPE. We compared the transcriptome of ARPE-19 cells kept in long-term culture with those of primary and other human RPE cells to assess the former's inherent plasticity relative to the latter. ARPE-19 cells at passages 9 to 12 grown in DMEM containing high glucose and pyruvate with 1% fetal bovine serum were differentiated for up to 4 months. Immunocytochemistry was performed on ARPE-19 cells grown on filters. Total RNA extracted from ARPE-19 cells cultured for either 4 days or 4 months was used for RNA sequencing (RNA-Seq) analysis using a 2 × 50 bp paired end protocol. The RNA-Seq data were analyzed to identify the affected pathways and recognize shared ontological classification among differentially expressed genes. RPE-specific mRNAs and miRNAs were assessed with quantitative real-time (RT)-PCR, and proteins with western blotting. ARPE-19 cells grown for 4 months developed the classic native RPE phenotype with heavy pigmentation. RPE-expressed genes, including RPE65, RDH5, and RDH10, as well as miR-204/211, were greatly increased in the ARPE-19 cells maintained at confluence for 4 months. The RNA-Seq analysis provided a comprehensive view of the relative abundance and differential expression of the genes in the differentiated ARPE-19 cells. Of the 16,757 genes with detectable signals, nearly 1,681 genes were upregulated, and 1,629 genes were downregulated with a fold change

  8. Potential methane reservoirs beneath Antarctica

    NARCIS (Netherlands)

    Wadham, J.L.; Arndt, S.|info:eu-repo/dai/nl/304835706; Tulaczyk, S.; Stibal, M.; Tranter, M.; Telling, J.; Lis, G.P.; Lawson, E.; Ridgwell, A.; Dubnick, A.; Sharp, M.J.; Anesio, A.M.; Butler, C.E.H.

    2012-01-01

    Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been

  9. Direct profiling of environmental microbial populations by thermal dissociation analysis of native rRNAs hybridized to oligonucleotide microarrays

    NARCIS (Netherlands)

    Fantroussi, El S.; Urakawa, H.; Bernhard, A.E.; Kelly, J.J.; Noble, P.A.; Smidt, H.; Yershov, G.M.; Stahl, D.A.

    2003-01-01

    Oligonucleotide microarrays were used to profile directly extracted rRNA from environmental microbial populations without PCR amplification. In our initial inspection of two distinct estuarine study sites, the hybridization patterns were reproducible and varied between estuarine sediments of

  10. Are Invasive Species Stressful? The Glucocorticoid Profile of Native Lizards Exposed to Invasive Fire Ants Depends on the Context.

    Science.gov (United States)

    Graham, Sean P; Freidenfelds, Nicole A; Thawley, Christopher J; Robbins, Travis R; Langkilde, Tracy

    Invasive species represent a substantial threat to native species worldwide. Research on the impacts of invasive species on wild living vertebrates has focused primarily on population-level effects. The sublethal, individual-level effects of invaders may be equally important but are poorly understood. We investigated the effects of invasive fire ants (Solenopsis invicta) on the physiological stress response of a native lizard (Sceloporus undulatus) within two experimental contexts: directly exposing lizards to a fire ant attack and housing lizards with fire ants in seminatural field enclosures. Lizards directly exposed to brief attack by fire ants had elevated concentrations of the stress hormone corticosterone (CORT), suggesting that these encounters can be physiologically stressful. However, lizards exposed for longer periods to fire ants in field enclosures had lower concentrations of CORT. This may indicate that the combined effects of confinement and fire ant exposure have pushed lizards into allostatic overload. However, lizards from fire ant enclosures appeared to have intact negative feedback controls of the stress response, evidenced by functioning adrenocorticotropic hormone responsiveness and lack of suppression of innate immunity (plasma bactericidal capacity). We review previous studies examining the stress response of wild vertebrates to various anthropogenic stressors and discuss how these-in combination with our results-underscore the importance of considering context (the length, frequency, magnitude, and types of threat) when assessing these impacts.

  11. The idol beneath the altar.

    Science.gov (United States)

    Clemens, Norman A

    2014-03-01

    Drawing on the imagery of a Mayan idol hidden beneath the altar of a Catholic mission church imposed on a Mayan city by Spanish conquerors, the author discusses the role of deeply rooted core beliefs that are not always evident on the surface-and the observation that, in clinical practice, things are not always as they seem. Psychotherapists may unconsciously be seen as invading cultural enemies.

  12. The Use of Pacific Menhaden Oil and Palm Oil on Lipid Metabolism Profile in Blood Serum of Native Cockerels

    Directory of Open Access Journals (Sweden)

    Ning Iriyanti

    2005-05-01

    Full Text Available Cholesterol is an important component of cell membrane, plasma lipoprotein and precursor of steroid synthesis in biologically crucial bile salt and steroid hormones.  Cholesterol level in the blood exceeding the 300 mg/100 ml can result in the incident of cardiac disorder. Cholesterol, HDL (High Density of Lipoprotein, LDL (Low Density of Lipo protein biosynthesis in the blood plasma of broiler chicken can be manipulated by the use of Pacific Menhaden Oil and Palm Oil.  Therefore, The aim of the current experiment was to investigate the effect of  long chain fatty acid from Pacific Menhaden Oil (PMO and Palm Oil (PO use in feed on the blood level of cholesterol, HDL and LDL of native cockerels. Four kinds of ration which contained different levels of PMO and PO were formulated.  They were R0 (control, without PMO and PO; R1 (10% PO; R2  (10% PMO and R3 (5% PMO and 5% PO.  A total of 72 native cockerels, aged two weeks were kept in 24 pens, three cockerels in each pen.  Each experimental unit were assingned at random to receive one of the four rations in completely randomized designed with six replicates. The use of PMO and PO in feed did not significantly affect (P>0.05 the concentration of cholesterol, HDL, LDL and triglyceride in the blood.  Although statistically was not significantly significant, Cockerels fed R2 had the highest concentration of HDL (39.36 mg/dl and the lowest concentration of LDL (9.10 in the blood. (Animal Production 7(2: 67-73 (2005   Key Words: Pacific Menhaden Oil, Palm Oil, Cholesterol, HDL, LDL, Triglyceride

  13. Nonuniform subduction of the Indian crust beneath the Himalayas.

    Science.gov (United States)

    Guo, Xiaoyu; Li, Wenhui; Gao, Rui; Xu, Xiao; Li, Hongqiang; Huang, Xingfu; Ye, Zhuo; Lu, Zhanwu; Klemperer, Simon L

    2017-10-02

    Himalayan tectonic activity is triggered by downward penetration of the Indian plate beneath the Asian plate. The subsurface geometry of this interaction has not been fully investigated. This study presents novel constraints on this geometry provided by two newly obtained, deep seismic reflection profiles. The profiles cover 100- and 60-km transects across the Yarlung-Zangbo suture of the Himalaya-Tibet orogen at c. 88°E. Both profiles show a crustal-scale outline of the subducting Indian crust. This outline clearly shows Indian understhrusting southern Tibet, but only to a limited degree. When combined with a third seismic reflection profile of the western Himalayas, the new profiles reveal progressive, eastward steepening and shortening in the horizontal advance of the subducting Indian crust.

  14. Cognitive profiles in bilingual children born to immigrant parents and Italian monolingual native children with specific learning disorders

    Directory of Open Access Journals (Sweden)

    Riva A

    2016-12-01

    Full Text Available Anna Riva, Renata Nacinovich, Nadia Bertuletti, Valentina Montrasi, Sara Marchetti, Francesca Neri, Monica Bomba Child and Adolescent Mental Health Department, University of Milan Bicocca, San Gerardo Hospital, Monza, Italy Purpose: The aim of this study is to compare the Wechsler Intelligence Scale for Children® – fourth edition IV (WISC IV intellectual profile of two groups of children with specific learning disorder, a group of bilingual children and a group of monolingual Italian children, in order to identify possible significant differences between them. Patients and methods: A group of 48 bilingual children and a group of 48 Italian monolingual children were included in this study. A preliminary comparison showed the homogeneity of the two groups regarding learning disorder typology and sociodemographic characteristics (age at WISC IV assessment, sex and years of education in Italy with the exception of socioeconomic status. Socioeconomic status was then used as a covariate in the analysis. Results: Even if the two groups were comparable in specific learning disorder severity and, in particular, in the text comprehension performance, our findings showed that the WISC IV performances of the bilingual group were significantly worse than the Italian group in Full Scale Intelligence Quotient (P=0.03, in General Ability Index (P=0.03, in Working Memory Index (P=0.009 and in some subtests and clusters requiring advanced linguistic abilities. Conclusion: These results support the hypothesis of a weakness in metalinguistic abilities in bilingual children with specific learning disorders than monolinguals. If confirmed, this result must be considered in the rehabilitation treatment. Keywords: children, bilingualism, WISC IV, SLD

  15. Structures of Active Blind Thrusts Beneath Tokyo Metropolitan Area

    Science.gov (United States)

    Ishiyama, T.; Sato, H.; Kato, N.; Nakayama, T.; Iwasaki, T.; Abe, S.

    2011-12-01

    We show structural models of active blind thrust faults beneath Tokyo metropolitan area, based on actively deforming landforms, Quaternary stratigraphy, and deep to shallow high-resolution seismic reflection data tied with these stratigraphic constraints, resolving seismic hazards from otherwise elusive active structures beneath highly urbanized areas. At the leading edge of the subducting Philippine Sea plate beneath the Kanto region, most significant active structures are recognized as folding and/or faulting of late Pleistocene and Holocene fluvial and marine deposits. Newly obtained seismic reflection profile and reprocessed sections indicate that these active structures are surface manifestations of emergent splay thrust faults extending from a subduction megathrust that generated the A.D.1923 Kanto earthquake (M7.9). Much slower rates of slip along these structures (~ 4.2 mm/yr) than slip deficits (~ 30 mm/yr) indicate that slip partitioning might have occurred between the subduction megathrust and splay faults. In contrast to these megathrust-related structures, steeply dipping blind thrusts are distributed beneath the Kanto plain underlain by several thousand meters thick Neogene forearc basin and shallow marine to terrestrial sediments (Kazusa and Shimousa Group). Deep seismic reflection profiles corroborate that these blind thrusts are reactivated normal faults originally formed due to early to middle Miocene extensional tectonics. While rates of slip along these structures are commonly slow (~0.1 mm/yr) based on offsets of late Pleistocene terrace deposits, their proximity to the metropolitan area urges more intense efforts to identify their potential seismic hazards including locations, sizes, rates of slip, and geometries of blind thrusts.

  16. Transient slab flattening beneath Colombia

    Science.gov (United States)

    Wagner, L. S.; Jaramillo, J. S.; Ramírez-Hoyos, L. F.; Monsalve, G.; Cardona, A.; Becker, T. W.

    2017-07-01

    Subduction of the Nazca and Caribbean Plates beneath northwestern Colombia is seen in two distinct Wadati Benioff Zones, one associated with a flat slab to the north and one associated with normal subduction south of 5.5°N. The normal subduction region is characterized by an active arc, whereas the flat slab region has no known Holocene volcanism. We analyze volcanic patterns over the past 14 Ma to show that in the mid-Miocene a continuous arc extended up to 7°N, indicating normal subduction of the Nazca Plate all along Colombia's Pacific margin. However, by 6 Ma, we find a complete cessation of this arc north of 3°N, indicating the presence of a far more laterally extensive flat slab than at present. Volcanism did not resume between 3°N and 6°N until after 4 Ma, consistent with lateral tearing and resteepening of the southern portion of the Colombian flat slab at that time.

  17. Continental crust beneath southeast Iceland

    Science.gov (United States)

    Torsvik, Trond H.; Amundsen, Hans E. F.; Trønnes, Reidar G.; Doubrovine, Pavel V.; Gaina, Carmen; Kusznir, Nick J.; Steinberger, Bernhard; Corfu, Fernando; Ashwal, Lewis D.; Griffin, William L.; Werner, Stephanie C.; Jamtveit, Bjørn

    2015-01-01

    The magmatic activity (0–16 Ma) in Iceland is linked to a deep mantle plume that has been active for the past 62 My. Icelandic and northeast Atlantic basalts contain variable proportions of two enriched components, interpreted as recycled oceanic crust supplied by the plume, and subcontinental lithospheric mantle derived from the nearby continental margins. A restricted area in southeast Iceland—and especially the Öræfajökull volcano—is characterized by a unique enriched-mantle component (EM2-like) with elevated 87Sr/86Sr and 207Pb/204Pb. Here, we demonstrate through modeling of Sr–Nd–Pb abundances and isotope ratios that the primitive Öræfajökull melts could have assimilated 2–6% of underlying continental crust before differentiating to more evolved melts. From inversion of gravity anomaly data (crustal thickness), analysis of regional magnetic data, and plate reconstructions, we propose that continental crust beneath southeast Iceland is part of ∼350-km-long and 70-km-wide extension of the Jan Mayen Microcontinent (JMM). The extended JMM was marginal to East Greenland but detached in the Early Eocene (between 52 and 47 Mya); by the Oligocene (27 Mya), all parts of the JMM permanently became part of the Eurasian plate following a westward ridge jump in the direction of the Iceland plume. PMID:25825769

  18. Electromagnetic Mapping of Electrical Conductivity Beneath the Columbia Basalts

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, H. Frank; Shoham, Yoram; Hoversten, G. Michael; Torres-Verdin, Carlos

    1992-01-02

    Sedimentary rocks beneath the Columbia River Basalt Group are recognized as having potential for oil and gas production, but the overlying layered basalts effectively mask seismic reflections from the underlying sediments. Four electromagnetic (EM) methods have been applied on profiles crossing Boylston Ridge, a typical east-west trending anticline of the Yakima Fold Belt, in an attempt to map the resistivity interface between the basalts and the sediments and to map variations in structure and resistivity within the sediments. The EM surveys detected strong variations in resistivity within the basalts, and in particular the continuous magnetotelluric array profiling (EMAP) revealed resistivity lows beneath the surface anticlines. These low resistivity zones probably coincide with fracturing in the core of the anticlines and they appear to correlate well with similar zones of low seismic velocity observed on a nearby seismic profile. The controlled-source EM surveys (in-loop transient, long-offset transient, and variable-offset frequency-domain) were designed in anticipation of relatively uniform high resistivity basalts, and were found to have been seriously distorted by the intrabasalt conductors discovered in the field. In particular, the resistivity sections derived from 1D inversions were found to be inconsistent and misleading. The EMAP survey provided the most information about the subsurface resistivity distribution, and was certainly the most cost-effective. However, both controlled-source and EMAP surveys call for accurate 2D or 3D inversion to accommodate the geological objectives of this project. [References: 18

  19. Electromagnetic mapping of electrical conductivity beneath the Columbia basalts

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, H.F.; Hoversten, G.M [Lawrence Berkeley Lab., CA (United States); Shoham, Y. [Shell Development Corp., Houston, TX (United States); Torres-Verdin, C. [Schlumberger-Doll Research, Ridgefield, CT (United States)

    1996-11-01

    Sedimentary rocks beneath the Columbia River Basalt Group are recognized as having potential for oil and gas production, but the overlying layered basalts effectively mask seismic reflections from the underlying sediments. Four electromagnetic (EM) methods have been applied on profiles crossing Boylston Ridge, a typical east-west trending anticline of the Yakima Fold Belt, in an attempt to map the resistivity interface between the basalts and the sediments and to map variations in structure and resistivity within the sediments. The EM surveys detected strong variations in resistivity within the basalts, and in particular the continuous magnetotelluric array profiling (EMAP) revealed resistivity lows beneath the surface anticlines. These low resistivity zones probably coincide with fracturing in the core of the anticlines and they appear to correlate well with similar zones of low seismic velocity observed on a nearby seismic profile. The controlled-source EM surveys (in-loop transient, long-offset transient, and variable-offset frequency-domain) were designed in anticipation of relatively uniform high resistivity basalts, and were found to have been seriously distorted by the intrabasalt conductors discovered in the field. In particular, the resistivity sections derived from 1D inversions were found to be inconsistent and misleading. The EMAP survey provided the most information about the subsurface resistivity distribution, and was certainly the most cost-effective. However, both controlled-source and EMAP surveys call for accurate 2D or 3D inversion to accommodate the geological objectives of this project.

  20. Slow upper mantle beneath Southern Norway from surface waves

    Science.gov (United States)

    Weidle, C.; Maupin, V.

    2009-04-01

    A recent regional surface wave tomography for Northern Europe revealed unprecedented images of the upper mantle beneath the (Tertiary) North Atlantic and the bordering Fennoscandian craton of Archean-Proterozoic age. With respect to the circum-Atlantic regions of uplift, no common mantle pattern supporting the uplift of these regions is observed. The western boundary of the thick cratonic lithosphere follows the trend of the continental margin offshore northern Norway (i.e. the northern Scandes are underlain by thick lithosphere) whereas further south the boundary of the craton is located further east beneath southwestern Sweden. SV shear wave velocities beneath southern Norway are 10% slower than ak135 (at 70-115 km depth) and these low-velocities are clearly connected to the North Atlantic low-velocity regime through a ~ 400 km wide "channel". The low-velocity anomaly beneath Southern Norway coincides in geometry roughly with the dome-like high topography of the southern Scandes and may thus have a non-negligible contribution to the isostatic balance of the region. The amplitude and depth-distribution of this anomaly are due to be further constrained by new data that were acquired during the MAGNUS experiment in 2006-2008. The temporary seismic network, consisting of 40 broadband seismometers covers to a large extent the location of the anomaly as imaged by the regional tomography. This enables us to get unique control on the tomographic model at improved lateral and vertical resolution. Preliminary analysis of surface wave phase velocities yields an average 1-D shear wave velocity profile for southern Norway as a first step to constrain the presence and depth extent of this low-velocity anomaly.

  1. The ionospheric heating beneath the magnetospheric cleft revisited

    Directory of Open Access Journals (Sweden)

    G. W. Prölss

    2005-03-01

    Full Text Available A prominent peak in the electron temperature of the topside ionosphere is observed beneath the magnetospheric cleft. The present study uses DE-2 data obtained in the Northern Winter Hemisphere to investigate this phenomenon. First, the dependence of the location and magnitude of the temperature peak on the magnetic activity is determined. Next, using a superposed epoch analysis, the mean latitudinal profile of the temperature enhancement is derived. The results of the present study are compared primarily with those obtained by Titheridge (1976, but also with more recent observations and theoretical predictions.

  2. Effects of herbage allowance of native grasslands in purebred and crossbred beef cows: metabolic, endocrine and hepatic gene expression profiles through the gestation-lactation cycle.

    Science.gov (United States)

    Laporta, J; Astessiano, A L; López-Mazz, C; Soca, P; Espasandin, A C; Carriquiry, M

    2014-07-01

    Our objective was to evaluate the metabolic, endocrine and hepatic mRNA profiles through the gestation-lactation cycle in purebred (PU: Angus and Hereford) and crossbred (CR: reciprocal F1 crosses) mutliparous beef cows (n=32), grazing on two herbage allowances of native pastures (2.5 v. 4 kg dry matter/kg BW; LO v. HI) and their associations with cow's productive performance (calf birth weight, milk production and commencement of luteal activity). Cow BW, body condition score (BCS) and blood samples were collected monthly, starting at -165 days relative to calving (days), and every 2 weeks after calving until +60 days of lactation. Liver biopsies were collected at -165, -75, -45, -15±10, and +15 and +60±3 days. Metabolic, endocrine and hepatic gene expression profiles, and calf birth weight, milk yield and postpartum commencement of luteal activity were evaluated. Overall, the most pronounced changes in metabolic, endocrine and hepatic gene expression occurred during winter gestation (-165 to -45 days), when all cows experienced the onset of a negative energy balance (decreased BCS, glucose and insulin, and increased non-esterified fatty acid concentrations, P<0.008). Concentrations of insulin and IGF-I were greater (P<0.037) in HI than in LO cows. However, serum IGF-I concentrations and hepatic growth hormone receptor (GHR) and IGF1 mRNA decreased (P<0.05) during the winter gestation period only in HI cows. Although IGF-I concentrations decreased (P<0.05) during the early postpartum (-15 v.+15 days) for all cows, the typical molecular mechanism that control the uncoupling of the growth hormone-IGF1 axis during the transition period of the dairy cattle (reduced hepatic GHR1A and IGF-I mRNA) was not observed in this study. The hepatic mRNA expression of key transcripts involved in gluconeogenesis and fatty-acid oxidation were upregulated (P<0.05) during winter gestation (from -165 to -45, -15 or +15 days, depending on the cow groups). Particularly, acyl

  3. Pressure generation beneath a new thermoplastic cast.

    Science.gov (United States)

    Mohler, L R; Pedowitz, R A; Byrne, T P; Gershuni, D H

    1996-01-01

    A new cast immobilizer that is heat-shrunk to conform to an injured extremity was examined. The purpose of these studies was to compare pressures beneath the thermoplastic cast with those beneath fiberglass casts on a laboratory model and on the forearms of human volunteers. Pressures measured beneath fiberglass casts on metal cylinders averaged 36 mm Hg. Thermoplastic casts on the smaller cylinder that allowed 42% shrinkage produced a mean pressure of 25 mm Hg; those placed on the larger cylinder that allowed 17% shrinkage produced a mean pressure of 39 mm Hg. Pressures measured on the forearms of healthy volunteers averaged 22 mm Hg beneath fiberglass casts and 31 mm Hg beneath the thermoplastic casts. These pressures were considerably less than pressures that have been shown to occlude the microcirculation of the skin. Acute compartment syndromes result from swelling within a limited space and remain a serious concern clinically when swelling is anticipated under any type of constraining cast. The results of these studies indicate that the new cast should not produce a greater risk of circulatory compromise to the limb than previously used fiberglass materials.

  4. A gender-oriented comparison between the mental health profiles of Bulgarian immigrants forcibly migrated to Turkey and the native population 15 years after migration.

    Science.gov (United States)

    Yenilmez, Cinar; Ayranci, Unal; Topal, Serdar; Aksaray, Gokay; Seber, Gülten; Kaptanoglu, Cem

    2007-01-01

    Background. The considerable problem of the migration of people, mainly from developing or undeveloped countries to developed countries, is a worldwide issue. The aims of this study were to compare, according to gender, scores obtained pertaining to mental symptom distributions of Bulgarian immigrants arriving in one city of west Turkey in 1989 with those of native-born citizens, as well as to the scores obtained from the scales of anxiety, hopelessness, job and life satisfaction. Methods. During the period of study between 1 February and 31 April 2003, short symptom inventory, state and trait anxiety scales, and hopelessness, job, and life satisfaction scales were collected from 85 immigrants living in a district where immigrants are prevalent. The results of 98 of the native population living in the same district were also collected during the same period. Data were analyzed using chi-square, t, Mann-Whitney U-tests, and percent ratios. Upon comparison of the scores of both immigrant women and native women, and immigrant men and native men, no differences were found between scores obtained from the subscales of short symptom inventory, state and trait anxiety scales, and hopelessness and job satisfaction scales (p>0.05). The only observable difference was between scores obtained from the life satisfaction scale (pTurkey. An alternative view could be that those entering the country may have adapted to the environment after the passage of 15 years. Furthermore, the significant difference seen between immigrant women and men, and native women and men in terms of symptoms of depression and somatization, respectively, may be explained through the notion that women perceived migration to be more different, and that native women more readily accepted the thought of physical illness according to mental disorders. Further studies are needed to better explain some of these results.

  5. Positive effects of non-native grasses on the growth of a native annual in a southern california ecosystem.

    Directory of Open Access Journals (Sweden)

    Gregory J Pec

    Full Text Available Fire disturbance is considered a major factor in the promotion of non-native plant species. Non-native grasses are adapted to fire and can alter environmental conditions and reduce resource availability in native coastal sage scrub and chaparral communities of southern California. In these communities persistence of non-native grasses following fire can inhibit establishment and growth of woody species. This may allow certain native herbaceous species to colonize and persist beneath gaps in the canopy. A field manipulative experiment with control, litter, and bare ground treatments was used to examine the impact of non-native grasses on growth and establishment of a native herbaceous species, Cryptantha muricata. C. muricata seedling survival, growth, and reproduction were greatest in the control treatment where non-native grasses were present. C. muricata plants growing in the presence of non-native grasses produced more than twice the number of flowers and more than twice the reproductive biomass of plants growing in the treatments where non-native grasses were removed. Total biomass and number of fruits were also greater in the plants growing in the presence of non-native grasses. Total biomass and reproductive biomass was also greater in late germinants than early germinants growing in the presence of non-native grasses. This study suggests a potential positive effect of non-native grasses on the performance of a particular native annual in a southern California ecosystem.

  6. Post-Mazama (7 KA) faulting beneath Upper Klamath Lake, Oregon

    Science.gov (United States)

    Colman, Steven M.; Rosenbaum, J.G.; Reynolds, R.L.; Sarna-Wojcicki, A. M.

    2000-01-01

    High-resolution seismic-reflection profiles (3.5 kHz) show that a distinctive, widespread reflection occurs in the sediments beneath Upper Klamath Lake, Oregon. Coring reveals that this reflection is formed by Mazama tephra (MT), about 7 ka in age. The MT horizon is faulted in many places and locally displaced by as much as 3.1 m. Differential displacement of multiple horizons indicates recurrent fault movement, perhaps three episodes since deposition of the Mazama. The pattern of faulting indicates northeast-southwest extension beneath the lake basin.

  7. Magmatic underplating beneath the Rajmahal Traps: Gravity ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The early Cretaceous thermal perturbation beneath the eastern continental margin of the Indian shield resulted in the eruption of the Rajmahal Traps. To understand the impact of the magmatic process that originated in the deep mantle on the lower crustal level of the eastern Indian shield and adjoining Bengal basin the ...

  8. Capturing the flow beneath water waves.

    Science.gov (United States)

    Nachbin, A; Ribeiro-Junior, R

    2018-01-28

    Recently, the authors presented two numerical studies for capturing the flow structure beneath water waves (Nachbin and Ribeiro-Junior 2014 Disc. Cont. Dyn. Syst. A 34 , 3135-3153 (doi:10.3934/dcds.2014.34.3135); Ribeiro-Junior et al. 2017 J. Fluid Mech. 812 , 792-814 (doi:10.1017/jfm.2016.820)). Closed orbits for irrotational waves with an opposing current and stagnation points for rotational waves were some of the issues addressed. This paper summarizes the numerical strategies adopted for capturing the flow beneath irrotational and rotational water waves. It also presents new preliminary results for particle trajectories, due to irrotational waves, in the presence of a bottom topography.This article is part of the theme issue 'Nonlinear water waves'. © 2017 The Author(s).

  9. Lower Crustal and Moho Reflections Beneath Mount St. Helens

    Science.gov (United States)

    Levander, A.; Kiser, E.; Zelt, C. A.; Creager, K.; Ulberg, C. W.; Schmandt, B.; Hansen, S. M.; Abers, G. A.

    2016-12-01

    The multi-disciplinary project iMUSH (imaging Magma Under St. Helens) was designed to illuminate the magmatic system beneath Mount St Helens (MSH) from the subducting Juan de Fuca slab to the surface using seismic, magnetotelluric, and petrologic data. The iMUSH active source experiment consisted of 23 large shots and 6000 seismograph locations. Included in the active-source seismic experiment were 2 dense linear profiles striking NW-SE and NE-SW, each with over 1000 receivers ( 150 m spacing) and 8 shots. Using the 1D average velocity model around MSH determined from travel-time analysis (Kiser et al., 2016, Geology), we have common-midpoint stacked STA/LTA envelope functions from all of the data along the NW-SE profile. A number of bright reflection events in the CMP section show remarkably good correspondence with abrupt velocity changes that were imaged in the 2D travel-time analysis in the mid to lower crust and at the Moho: Reflections appear at 20-25 km depth at the tops of two lower crustal high velocity (Vp > 7.5 km/s) bodies. One of these high velocity bodies is directly beneath MSH. The other is 40 km SE of MSH, under the Indian Heaven volcanic field, a basaltic field last active 9 ka. We have interpreted the high velocity bodies as cumulates from Quaternary or Tertiary volcanism. Separating the two high Vp bodies is a lower velocity column (Vp ≤ 6.5 km/s) dipping to the SE from the midcrust to the Moho. In the CMP section, the Moho reflection is bright under the region of low velocity and dims beneath both of the high velocity lower crustal bodies. Seismicity associated with the 1980 eruption extended from the summit to 20 km depth, stopping just above the bright reflection at the top of the MSH high Vp body. Deep long period events under MSH, often associated with motion of magmatic fluids, cluster at 20-30 km depth along the southeastern edge of the same reflection. This leads us to suggest that lower crustal magmas migrate along the southeastern

  10. The Ocean Boundary Layer beneath Hurricane Frances

    Science.gov (United States)

    Dasaro, E. A.; Sanford, T. B.; Terrill, E.; Price, J.

    2006-12-01

    The upper ocean beneath the peak winds of Hurricane Frances (57 m/s) was measured using several varieties of air-deployed floats as part of CBLAST. A multilayer structure was observed as the boundary layer deepened from 20m to 120m in about 12 hours. Bubbles generated by breaking waves create a 10m thick surface layer with a density anomaly, due to the bubbles, of about 1 kg/m3. This acts to lubricate the near surface layer. A turbulent boundary layer extends beneath this to about 40 m depth. This is characterized by large turbulent eddies spanning the boundary layer. A stratified boundary layer grows beneath this reaching 120m depth. This is characterized by a gradient Richardson number of 1/4, which is maintained by strong inertial currents generated by the hurricane, and smaller turbulent eddies driven by the shear instead of the wind and waves. There is little evidence of mixing beneath this layer. Heat budgets reveal the boundary layer to be nearly one dimensional through much of the deepening, with horizontal and vertical heat advection becoming important only after the storm had passed. Turbulent kinetic energy measurements support the idea of reduced surface drag at high wind speeds. The PWP model correctly predicts the degree of mixed layer deepening if the surface drag is reduced at high wind speed. Overall, the greatest uncertainty in understanding the ocean boundary layer at these extreme wind speeds is a characterization of the near- surface processes which govern the air-sea fluxes and surface wave properties.

  11. Native iron

    DEFF Research Database (Denmark)

    Brooks, Charles Kent

    2015-01-01

    , a situation unique in the Solar System. In such a world, iron metal is unstable and, as we all know, oxidizes to the ferric iron compounds we call 'rust'. If we require iron metal it must be produced at high temperatures by reacting iron ore, usually a mixture of ferrous (Fe2+) and ferric (Fe3+) oxides (Fe2O3......, hematite, or FeO.Fe2O3, magnetite), with carbon in the form of coke. This is carried out in a blast furnace. Although the Earth's core consists of metallic iron, which may also be present in parts of the mantle, this is inaccessible to us, so we must make our own. In West Greenland, however, some almost...... unique examples of iron metal, otherwise called 'native iron' or 'telluric iron', occur naturally....

  12. Analysis of groundwater flow beneath ice sheets

    Energy Technology Data Exchange (ETDEWEB)

    Boulton, G. S.; Zatsepin, S.; Maillot, B. [Univ. of Edinburgh (United Kingdom). Dept. of Geology and Geophysics

    2001-03-01

    The large-scale pattern of subglacial groundwater flow beneath European ice sheets was analysed in a previous report. It was based on a two-dimensional flowline model. In this report, the analysis is extended to three dimensions by exploring the interactions between groundwater and tunnel flow. A theory is developed which suggests that the large-scale geometry of the hydraulic system beneath an ice sheet is a coupled, self-organising system. In this system the pressure distribution along tunnels is a function of discharge derived from basal meltwater delivered to tunnels by groundwater flow, and the pressure along tunnels itself sets the base pressure which determines the geometry of catchments and flow towards the tunnel. The large-scale geometry of tunnel distribution is a product of the pattern of basal meltwater production and the transmissive properties of the bed. The tunnel discharge from the ice margin of the glacier, its seasonal fluctuation and the sedimentary characteristics of eskers are largely determined by the discharge of surface meltwater which penetrates to the bed in the terminal zone. The theory explains many of the characteristics of esker systems and can account for tunnel valleys. It is concluded that the large-scale hydraulic regime beneath ice sheets is largely a consequence of groundwater/tunnel flow interactions and that it is essential similar to non-glacial hydraulic regimes. Experimental data from an Icelandic glacier, which demonstrates measured relationships between subglacial tunnel flow and groundwater flow during the transition from summer to winter seasons for a modern glacier, and which support the general conclusions of the theory is summarised in an appendix.

  13. Subducting characteristic of the Pacific slab beneath northeast China

    Science.gov (United States)

    Jiang, G.; Zhang, G.; Xu, Y.

    2012-12-01

    The volcanoes locating in northeast China are very active. Some researchers consider that the origin of volcanoes is closely related to the subducting western Pacific plate and the upwelling asthenosphere. The thickness and the existing range of the subducted plate are not clear as far although the seismic tomography results obviously show that the Pacific plate exists below the volcano region. Therefore, in this study, we adopted the method combining the teleseismic tomography with travel time forward modeling to further study the velocity structure beneath northeast China, especially the precise model of subducted Pacific plate. Our results show that (1) the average thickness and velocity perturbation of slab is 85 km and 1%, respectively, and the slab has not been thickened compared with the previous result of the Japan Sea; (2) the Pacific plate subducted into the mantle transition zone with a shallow dip angle, and changed horizontally when it touched the bottom of mantle transition zone, and extended westward to Longitude 127°E and then stops over there; (3) the horizontal slab locates right below the volcano region. These above features help people understand the origin of intraplate volcanoes and the geodynamical process better. (a) Tomographic result along 43°N. Red and blue colors represent the high and low velocity anomalies, respectively, and the scale is shown at the right-bottom; The profile line is shown in (b); The black triangles represent the volcanoes locating near the profile; The black solid and dashed lines show the depths of upper and lower boundaries of Pacific plate, respectively. The red dots represent the deep earthquakes around the profile. (b) Location of profile AA' along 43°N. Black triangles denote volcanoes; White squares represent the stations; Blue contours denote the depth of upper boundary of Pacific plate; Black and red dots represent the deep epicenters.

  14. Native Americans with Diabetes

    Science.gov (United States)

    ... Read the MMWR Science Clips Native Americans with Diabetes Better diabetes care can decrease kidney failure Language: ... between 1996 and 2013. Problem Kidney failure from diabetes was highest among Native Americans. Native Americans are ...

  15. Profiling the native specific human humoral immune response to Sudan Ebola virus strain Gulu by chemiluminescence enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Sobarzo, Ariel; Perelman, Eddie; Groseth, Allison; Dolnik, Olga; Becker, Stephan; Lutwama, Julius Julian; Dye, John M; Yavelsky, Victoria; Lobel, Leslie; Marks, Robert S

    2012-11-01

    Ebolavirus, a member of the family Filoviridae, causes high lethality in humans and nonhuman primates. Research focused on protection and therapy for Ebola virus infection has investigated the potential role of antibodies. Recent evidence suggests that antibodies can be effective in protection from lethal challenge with Ebola virus in nonhuman primates. However, despite these encouraging results, studies have not yet determined the optimal antibodies and composition of an antibody cocktail, if required, which might serve as a highly effective and efficient prophylactic. To better understand optimal antibodies and their targets, which might be important for protection from Ebola virus infection, we sought to determine the profile of viral protein-specific antibodies generated during a natural cycle of infection in humans. To this end, we characterized the profile of antibodies against individual viral proteins of Sudan Ebola virus (Gulu) in human survivors and nonsurvivors of the outbreak in Gulu, Uganda, in 2000-2001. We developed a unique chemiluminescence enzyme-linked immunosorbent assay (ELISA) for this purpose based on the full-length recombinant viral proteins NP, VP30, and VP40 and two recombinant forms of the viral glycoprotein (GP(1-294) and GP(1-649)) of Sudan Ebola virus (Gulu). Screening results revealed that the greatest immunoreactivity was directed to the viral proteins NP and GP(1-649), followed by VP40. Comparison of positive immunoreactivity between the viral proteins NP, GP(1-649), and VP40 demonstrated a high correlation of immunoreactivity between these viral proteins, which is also linked with survival. Overall, our studies of the profile of immunorecognition of antibodies against four viral proteins of Sudan Ebola virus in human survivors may facilitate development of effective monoclonal antibody cocktails in the future.

  16. Bubble streams rising beneath an inclined surface

    Science.gov (United States)

    Bird, James; Brasz, Frederik; Kim, Dayoung; Menesses, Mark; Belden, Jesse

    2017-11-01

    Bubbles released beneath a submerged inclined surface can tumble along the wall as they rise, dragging the surrounding fluid with them. This effect has recently regained attention as a method to mitigate biofouling in marine environment, such as a ship hull. It appears that the efficacy of this approach may be related to the velocity of the rising bubbles and the extent that they spread laterally as they rise. Yet, it is unclear how bubble stream rise velocity and lateral migration depend on bubble size, flow rate, and inclination angle. Here we perform systematic experiments to quantify these relationships for both individual bubble trajectories and ensemble average statistics. Research supported by the Office of Naval Research under Grant Number award N00014-16-1-3000.

  17. Detecting slab structure beneath the Mediterranean

    Science.gov (United States)

    Miller, Meghan S.; Sun, Daoyuan; Piana Agostinetti, Nicola

    2013-04-01

    The presence of subducted slabs in the Mediterranean has been well documented with seismic tomography, however, these images, which are produced by smoothed, damped inversions, underestimate the sharpness of the structures. The position and extent of the slabs and the presence possible tears or gaps in the subducted lithosphere are still debated, yet the shape and location these structures are important for kinematic reconstructions and evolution of the entire subduction zone system. Extensive distribution of broadband seismic instrumentation in the Mediterranean (Italian National Seismic Network in Italy and the NSF-PICASSO project in Spain and Morocco) has allowed us to use alternative methodologies to detect the position of the slabs and slab tears beneath the Central and Western Mediterranean. Using S receiver functions we are able to identify S-to-p conversions from the bottom of the subducted slab and a lack of these signals where there are gaps or tears in the slab. We also analyze broadband waveforms for changes in P wave coda from deep (> 300 km depth) local earthquakes. The waveform records for stations in southern Italy and around the Betic-Rif show large amplitude, high frequency (f > 5 Hz) late arrivals with long coda after relatively low-frequency onset. High frequency arrivals are the strongest from events whose raypaths travel within the slab to the stations where they are recorded allowing for mapping of where the subducted material is located within the upper mantle. These two methods, along with inferring the slab position from fast P-wave velocity perturbations in tomography and intermediate depth seismicity, provide additional geophysical evidence to aid in interpretation of the complex, segmented slab structure beneath the Mediterranean.

  18. Shear wave anisotropy beneath the Tibetan Plateau

    Science.gov (United States)

    McNamara, Daniel E.; Owens, Thomas J.; Silver, Paul G.; Wu, Frances T.

    1994-07-01

    Eleven broadband digital seismic stations were deployed across the central Tibetan Plateau in the first extensive passive-source experiment attempted within the Tibetan Plateau. One year of recording resulted in 186 event-station pairs which we analyze to determine the characteristics of shear wave splitting in the upper mantle beneath the array. Measurements of the fast polarization direction (phi) and delay time (delta-t) for SKS and direct S arrivals reveal systematic variations along the north-south oriented array. In the north central region of the plateau, very large delay times are observed at three stations, the largest of which is BUDO with delta-t = 2.4 s. However, at TUNL, which is off the northern edge of the plateau and 110 km from BUDO, and at sites in the south central plateau, delta-t decreases by nearly a factor of 3. We also observe a systematic rotation of phi from about 45 deg (NE) to 90 deg (E-W) from south to north along the array. A previously identified zone of inefficient Sn propagation correlates well with our region of large delta-t observations. The large delay times suggest that a relatively high number of anisotropic crystals are preferentially alligned within the mantle-lid, beneath the north central portion of the Tibetan Plateau. In most cases, fast polarization directions appear to be parallel to surface geologic features suggesting as much as 200 km of the upper mantle has been involved in the collisional deformation that has produced the Tibetan Plateau.

  19. A detailed look beneath the surface: Evidence of a surface reconstruction beneath a capping layer

    Energy Technology Data Exchange (ETDEWEB)

    Krull, D., E-mail: dominique.krull@tu-dortmund.de [Lehrstuhl für Experimentelle Physik I and DELTA, Dortmund University of Technology, Otto-Hahn-Str. 4, 44221 Dortmund (Germany); Tesch, M.F. [University of Applied Sciences Münster, Stegerwaldstr. 39, 48565 Steinfurt (Germany); Schönbohm, F.; Lühr, T.; Keutner, C.; Berges, U. [Lehrstuhl für Experimentelle Physik I and DELTA, Dortmund University of Technology, Otto-Hahn-Str. 4, 44221 Dortmund (Germany); Mertins, H.-Ch. [University of Applied Sciences Münster, Stegerwaldstr. 39, 48565 Steinfurt (Germany); Westphal, C. [Lehrstuhl für Experimentelle Physik I and DELTA, Dortmund University of Technology, Otto-Hahn-Str. 4, 44221 Dortmund (Germany)

    2016-03-30

    Highlights: • Demonstration of a detailed look into internal interface structures. • Close-up view to an internal surface beneath a capping layer. • Resolving of inter-diffusion layers. • Imaging of phase-transition (local layers). • Demonstration of achieving magnetic information of an interlayer. - Abstract: Many physical effects are strongly depending on the composition of the interfaces between separating layers. Hence, the knowledge of the interfacial characteristics such as structure, chemical bonds, or magnetic properties of the corresponding materials is essential for an understanding and optimization of these effects. This study reports on a combined magnetic and structural analysis using X-ray photoelectron diffraction (XPD) and transverse magneto-optical Kerr effect (T-MOKE). The information depth of these methods is demonstrated by investigating the uppermost GaAs(001) layer beneath a Fe-film and the interfacial regimes of Fe/GaAs(001) beneath an MgO capping layer. Iron was prepared on a clean GaAs(001) surface and a GaAs(001)-(4 × 2)-reconstructed surface. Beneath the Fe-film, the (4 × 2)-reconstruction is not lifted, which is clearly shown by the diffraction pattern of the GaAs(4 × 2)-Fe surface. It is shown that Fe inter-diffusion, resulting in an amorphous interface, is almost prevented by the Ga-rich reconstruction. The magneto-optical measurements with T-MOKE clearly demonstrated the Fe-interlayer in a ferromagnetic state. We find no evidence for magnetic properties neither within the signal of the GaAs-substrate nor the MgO-film.

  20. A detailed look beneath the surface: Evidence of a surface reconstruction beneath a capping layer

    Science.gov (United States)

    Krull, D.; Tesch, M. F.; Schönbohm, F.; Lühr, T.; Keutner, C.; Berges, U.; Mertins, H.-Ch.; Westphal, C.

    2016-03-01

    Many physical effects are strongly depending on the composition of the interfaces between separating layers. Hence, the knowledge of the interfacial characteristics such as structure, chemical bonds, or magnetic properties of the corresponding materials is essential for an understanding and optimization of these effects. This study reports on a combined magnetic and structural analysis using X-ray photoelectron diffraction (XPD) and transverse magneto-optical Kerr effect (T-MOKE). The information depth of these methods is demonstrated by investigating the uppermost GaAs(001) layer beneath a Fe-film and the interfacial regimes of Fe/GaAs(001) beneath an MgO capping layer. Iron was prepared on a clean GaAs(001) surface and a GaAs(001)-(4 × 2)-reconstructed surface. Beneath the Fe-film, the (4 × 2)-reconstruction is not lifted, which is clearly shown by the diffraction pattern of the GaAs(4 × 2)-Fe surface. It is shown that Fe inter-diffusion, resulting in an amorphous interface, is almost prevented by the Ga-rich reconstruction. The magneto-optical measurements with T-MOKE clearly demonstrated the Fe-interlayer in a ferromagnetic state. We find no evidence for magnetic properties neither within the signal of the GaAs-substrate nor the MgO-film.

  1. Lithosphere-Asthenosphere Boundary Beneath Regions of Recent Volcanism in the Basin and Range Province and Mojave Desert

    Science.gov (United States)

    Forsyth, D. W.; Rau, C. J.; Plank, T.; Gazel, E.; Bendersky, C.

    2010-12-01

    Melt in the asthenosphere may contribute strongly to the development of the lithosphere-asthenosphere boundary (LAB) in some settings. We have compiled a set of vertical shear-velocity profiles beneath centers of recent (Hill and Amboy in the southern Mojave, the lithospheric lid extends to a depth of ~ 90 km. Minimum velocities in the LVZs beneath the higher velocity lids typically are 4.00-4.05 km/s, similar to that beneath the East Pacific Rise and too low to be caused by temperature alone without unreasonably high attenuation. Beneath other centers, like Big Pine, Lathrop Wells and Tahoe, there is no resolvable lid. The lid is either missing or too thin to resolve, but the absence of the lid/LVZ pattern seems to be due to a combination of lower velocities immediately beneath the Moho and higher velocities in the LVZ. Petrological indicators of temperature and depth of melting from basalt composition are in general agreement with the seismological observations, with the depth of last equilibration typically occurring near the top of the LVZ. Beneath Big Pine, for example, the equilibration temperatures are unusually low and the equilibration depth is 40 to 50 km, just below the Moho, in agreement with the lack of a distinct lid. Beneath Cima, equilibration depths are 60-70 km. Beneath Coso, equilibration depths are only slightly deeper than Big Pine, but the temperatures are higher, in agreement with the more pronounced LVZ and the presence of a thin lid. Beneath the Tabernacle Hill/Black Rock volcanic field in west-central Utah, there is a well-developed lid/LVZ structure, but the "high" velocity lid is only ~ 4.10 km/s while the underlying LVZ reaches as low as 3.90 km/s. This observation points to the importance of melt concentration or distribution controlling the velocities. Lid velocities are often relatively low (4.2-4.4 km/s) in the Basin and Range, indicating high temperatures, but here there is probably melt within the lid as well, with higher

  2. Investigating Late Cenozoic Mantle Dynamics beneath Yellowstone

    Science.gov (United States)

    Zhou, Q.; Liu, L.

    2015-12-01

    Recent tomography models (Sigloch, 2011; Schmandt & Lin, 2014) reveal unprecedented details of the mantle structure beneath the United States (U.S.). Prominent slow seismic anomalies below Yellowstone, traditionally interpreted as due to a mantle plume, are restricted to depths either shallower than 200 km or between 500 and 1000 km, but a continuation to greater depth is missing. Compared to fast seismic anomalies, which are usually interpreted as slabs or delaminated lithosphere, origin of deep slow seismic anomalies, especially those in the vicinity of subduction zones, is more enigmatic. As a consequence, both the dynamics and evolution of these slow anomalies remain poorly understood. To investigate the origin and evolution of the Yellowstone slow anomaly during the past 20 Myr, we construct a 4D inverse mantle convection model with a hybrid data assimilation scheme. On the one hand, we use the adjoint method to recover the past evolution of mantle seismic structures beyond the subduction zones. On the other hand, we use a high-resolution forward model to simulate the subduction of the oceanic (i.e., Farallon) plate. During the adjoint iterations, features from these two approaches are blended together at a depth of ~200 km below the subduction zone. In practice, we convert fast and slow seismic anomalies to effective positive and negative density heterogeneities. Our preliminary results indicate that at 20 Ma, the present-day shallow slow anomalies beneath the western U.S. were located inside the oceanic asthenosphere, which subsequently entered the mantle wedge, through the segmented Farallon slab. The eastward encroachment of the slow anomaly largely followed the Yellowstone hotspot track migration. The present deep mantle Yellowstone slow anomaly originated at shallower depths (i.e. transition zone), and was then translated down to the lower mantle accompanying the sinking fast anomalies. The temporal evolution of the slow anomalies suggests that the deep

  3. Turbulence beneath finite amplitude water waves

    Energy Technology Data Exchange (ETDEWEB)

    Beya, J.F. [Universidad de Valparaiso, Escuela de Ingenieria Civil Oceanica, Facultad de Ingenieria, Valparaiso (Chile); The University of New South Wales, Water Research Laboratory, School of Civil and Environmental Engineering, Sydney, NSW (Australia); Peirson, W.L. [The University of New South Wales, Water Research Laboratory, School of Civil and Environmental Engineering, Sydney, NSW (Australia); Banner, M.L. [The University of New South Wales, School of Mathematics and Statistics, Sydney, NSW (Australia)

    2012-05-15

    Babanin and Haus (J Phys Oceanogr 39:2675-2679, 2009) recently presented evidence of near-surface turbulence generated below steep non-breaking deep-water waves. They proposed a threshold wave parameter a {sup 2}{omega}/{nu} = 3,000 for the spontaneous occurrence of turbulence beneath surface waves. This is in contrast to conventional understanding that irrotational wave theories provide a good approximation of non-wind-forced wave behaviour as validated by classical experiments. Many laboratory wave experiments were carried out in the early 1960s (e.g. Wiegel 1964). In those experiments, no evidence of turbulence was reported, and steep waves behaved as predicted by the high-order irrotational wave theories within the accuracy of the theories and experimental techniques at the time. This contribution describes flow visualisation experiments for steep non-breaking waves using conventional dye techniques in the wave boundary layer extending above the wave trough level. The measurements showed no evidence of turbulent mixing up to a value of a {sup 2}{omega}/{nu} = 7,000 at which breaking commenced in these experiments. These present findings are in accord with the conventional understandings of wave behaviour. (orig.)

  4. Channelization of plumes beneath ice shelves

    KAUST Repository

    Dallaston, M. C.

    2015-11-11

    © 2015 Cambridge University Press. We study a simplified model of ice-ocean interaction beneath a floating ice shelf, and investigate the possibility for channels to form in the ice shelf base due to spatial variations in conditions at the grounding line. The model combines an extensional thin-film description of viscous ice flow in the shelf, with melting at its base driven by a turbulent ocean plume. Small transverse perturbations to the one-dimensional steady state are considered, driven either by ice thickness or subglacial discharge variations across the grounding line. Either forcing leads to the growth of channels downstream, with melting driven by locally enhanced ocean velocities, and thus heat transfer. Narrow channels are smoothed out due to turbulent mixing in the ocean plume, leading to a preferred wavelength for channel growth. In the absence of perturbations at the grounding line, linear stability analysis suggests that the one-dimensional state is stable to initial perturbations, chiefly due to the background ice advection.

  5. PICASSSO Ps Receiver Function Analysis of the Lithospheric Structure Beneath the Western Mediterranean

    Science.gov (United States)

    Thurner, S.; Palomeras, I.; Levander, A.

    2011-12-01

    Rif and Betic Mountains we observe complex crustal structures, possibly resulting from the associated thrust systems in each region. Along a profile across Morocco, we observe thick crust in the north beneath the Rif Mountains and to the south beneath the northern edge of the West African craton. Near the center of this transect, directly beneath the Atlas, we observe a much thinner crust at ~30-35 km. These receiver functions also reveal a clear LAB at variable depths throughout the study area, with up to a ~100% change in LAB depth from the southern region to the northern region. From south to north, we see an abrupt change in LAB depth from the High Atlas (~85-95 km) to the Middle Atlas (~65-70 km). The LAB remains relatively shallow beneath the Rif (~75 km) and thickens to the north beneath the Betic Mountains (~85-95 km) and the Iberian Massif (~100-125 km). These LAB depth estimates agree well with those from the surface wave analysis presented by Palomeras et al. (this session), and both data sets can be used to better constrain the LAB depth.

  6. Native Health Research Database

    Science.gov (United States)

    >*/ HSLIC Native American Health Information Services UNM Health Sciences Library and Informatics Center MSC09 5100 1 University of New Mexico Albuquerque, NM 87131-0001 Native Services Librarian Phone: ( ...

  7. Native American Homeschooling Association.

    Science.gov (United States)

    Rozon, Gina

    2000-01-01

    The Native American Home School Association helps Native parents to provide a good education free from the assimilationist tendencies of public school and to transmit Native values and culture. Discusses various home schooling styles, the effectiveness of home schooling in terms of academic achievement and socialization, and the effectiveness of…

  8. The large low velocity province and the vertical flow beneath the Pacific

    Science.gov (United States)

    Kawai, K.; Geller, R. J.; Tsuchiya, T.

    2010-12-01

    Since tomographic studies found the large low velocity province (LLVP) (degree-2 pattern) in the lowermost mantle in 1980's, it has been controversial whether it is due to thermal effects, chemical heterogeneity, or both. Geodynamical studies have suggested that both effects can explain the LLVP but that the large thermo-chemical pile model is preferred (e.g., Bull et al. 2009). Our seismological group has developed waveform inversion techniques and applied them to data from recently deployed broad-band seismic arrays such as US-Array. We found that there are notable S-velocity decreases beneath the D" discontinuity as the CMB is approached within the high average velocity regions such as the lowermost mantle beneath Central America, the Arctic, and Siberia (Kawai et al. 2007a,b, 2009). We also found "S-shaped" velocity models in the lowermost mantle in regions with low average S-velocity such as beneath the western Pacific and the Pacific (Konishi et al. 2009; Kawai & Geller 2010a). We performed analyses based on ab-initio mineral physics (Kawai & Tsuchiya 2009), which showed that these velocity profiles can be explained by a simple thermal boundary layer (TBL) model with a CMB temperature of about 3800 K. The TBL model can also explain most of the important seismological properties in the lowermost mantle such as the LLVP, so that the large thermo-chemical pile model appears to be inappropriate. On the other hand, the S-velocity model beneath Hawaii requires the existence of localized chemical heterogeneity (Kawai & Geller 2010b), which could be due to an accumulated Fe-rich dense pile (Kawai & Tsuchiya in prep.). To better constrain the nature of the LLVP, we inverted the horizontal components of observed radial and transverse waveforms of S and ScS phases to determine the radial profile of TI shear wave velocity at the northeastern edge of the LLVP in the lowermost mantle beneath the Pacific (Kawai & Geller 2010c). We find that the radial (SV) component is 3

  9. Seismic structure and composition of the crust beneath the southern Scandes, Norway

    DEFF Research Database (Denmark)

    Stratford, Wanda Rose; Thybo, Hans

    2011-01-01

    investigations of Norwegian uplift structure, refraction experiment) acquired data along three 300 to 400 km long active source seismic profiles across the Southwest Scandinavian Domain in southern Norway, the youngest section of the Fennoscandian shield. Moho depths in the Domain are 36–40 km, thinning towards...... the continental shelf and Oslo Graben. The high Vp lower crust beneath the Southwest Scandinavian Domain (Vp > 7 km/s) is around 4 km thick. Crustal structure in the adjacent Svecofennian Domain differs significantly; Moho depths reach ~ 50 km and an up to 24 km thick high Vp lower crust is present. Strong P...

  10. Electrical conductivity beneath the volcanoes of the NW Argentinian Puna

    National Research Council Canada - National Science Library

    Lezaeta, Pamela; Brasse, Heinrich

    2001-01-01

    ...., in the eastern Puna and backarc zone. The 2‐D conductivity models show a conductive zone beneath the eastern Puna shoshonitic volcanoes and nearby Tuzgle volcano, which reaches from the upper crust to the upper mantle...

  11. Comparative Study on the Electrical Properties of the Oceanic Mantle Beneath the Northwest Pacific Ocean

    Science.gov (United States)

    Toh, H.

    2013-12-01

    We have been conducting long-term seafloor electromagnetic (EM) observations at two sites in the northwest Pacific since 2001. The older site was established at the deep seafloor (~5600m) on the northwest Pacific basin (Site NWP), while the new one was installed on the west Philippine basin (Site WPB) in 2006 at the slightly deeper (~5700m) seafloor. The ages of the oceanic basins at those sites are approximately 129 Ma for Site NWP (Shipboard Scientific Party of ODP Leg 191, 2000) and 49 Ma for Site WPB (Salisbury et al., 2006), respectively. The EM instruments deployed at those sites are seafloor EM stations (SFEMS; Toh et al., 2004 and 2006) and capable of measuring vector EM fields at the seafloor for as long as one year or more with other physical quantities such as the instruments' attitude, orientation and temperature. One of the objectives of the seafloor long-term EM observations by SFEMSs is to make a comparative study of the oceanic mantle with and without influence of the so-called 'stagnant slabs' in terms of their electrical conductivity. It is anticipated that the mantle transition zone under the influence of the stagnant slab has a higher electrical conductivity because the transition zone there could be wetter than that in the absence of the stagnant slab. In this context, the mantle transition zone beneath Site WPB can be said to have influence by the stagnant slab, while that beneath Site NWP does not. It, therefore, is basically possible to estimate how much water is present in each transition zone by comparison of the electrical conductivity profiles of the two. The one-dimensional electrical profile beneath Site NWP has been derived so far using the magnetotelluric (MT) and geomagnetic depth sounding (GDS) methods with significant jumps in the electrical property at 410 and 660km discontinuities. The jumps are approximately factors of 10 and 2, respectively (Ichiki et al., 2009). Here we show a profile beneath Site WPB using both MT and GDS

  12. Profile: American Indian/Alaska Native

    Science.gov (United States)

    ... of Arizona, who have one of the highest diabetes rates in the world. AI/ANs also have disproportionately high death rates from unintentional injuries and suicide. In 2012, the tuberculosis rate for AI/NAs was 6.3, as ...

  13. NATIVE VS NON-NATIVE ENGLISH TEACHERS

    Directory of Open Access Journals (Sweden)

    Masrizal Masrizal

    2013-02-01

    Full Text Available Although the majority of English language teachers worldwide are non-native English speakers (NNS, no research was conducted on these teachers until recently. A pioneer research by Peter Medgyes in 1994 took quite a long time until the other researchers found their interests in this issue. There is a widespread stereotype that a native speaker (NS is by nature the best person to teach his/her foreign language. In regard to this assumption, we then see a very limited room and opportunities for a non native teacher to teach language that is not his/hers. The aim of this article is to analyze the differences among these teachers in order to prove that non-native teachers have equal advantages that should be taken into account. The writer expects that the result of this short article could be a valuable input to the area of teaching English as a foreign language in Indonesia.

  14. Major disruption of D'' beneath Alaska: D'' Beneath Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Daoyuan [Laboratory of Seismology and Physics of Earth' s Interior, School of Earth and Space Sciences, University of Science and Technology of China, Hefei Anhui China; National Geophysics Observatory at Mengcheng, Anhui China; Helmberger, Don [Seismological Laboratory, California Institute of Technology, Caltech, Pasadena California USA; Miller, Meghan S. [Department of Earth Sciences, University of Southern California, Los Angeles California USA; Jackson, Jennifer M. [Seismological Laboratory, California Institute of Technology, Caltech, Pasadena California USA

    2016-05-01

    D'' represents one of the most dramatic thermal and compositional layers within our planet. In particular, global tomographic models display relatively fast patches at the base of the mantle along the circum-Pacific which are generally attributed to slab debris. Such distinct patches interact with the bridgmanite (Br) to post-bridgmanite (PBr) phase boundary to generate particularly strong heterogeneity at their edges. Most seismic observations for the D'' come from the lower mantle S wave triplication (Scd). Here we exploit the USArray waveform data to examine one of these sharp transitions in structure beneath Alaska. From west to east beneath Alaska, we observed three different characteristics in D'': (1) the western region with a strong Scd, requiring a sharp δVs = 2.5% increase; (2) the middle region with no clear Scd phases, indicating a lack of D'' (or thin Br-PBr layer); and (3) the eastern region with strong Scd phase, requiring a gradient increase in δVs. To explain such strong lateral variation in the velocity structure, chemical variations must be involved. We suggest that the western region represents relatively normal mantle. In contrast, the eastern region is influenced by a relic slab that has subducted down to the lowermost mantle. In the middle region, we infer an upwelling structure that disrupts the Br-PBr phase boundary. Such an interpretation is based upon a distinct pattern of travel time delays, waveform distortions, and amplitude patterns that reveal a circular-shaped anomaly about 5° across which can be modeled synthetically as a plume-like structure rising about 400 km high with a shear velocity reduction of ~5%, similar to geodynamic modeling predictions of upwellings.

  15. MBS Native Plant Communities

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data layer contains results of the Minnesota County Biological Survey (MCBS). It includes polygons representing the highest quality native plant communities...

  16. The nature of subslab slow velocity anomalies beneath South America

    Science.gov (United States)

    Portner, Daniel Evan; Beck, Susan; Zandt, George; Scire, Alissa

    2017-05-01

    Slow seismic velocity anomalies are commonly imaged beneath subducting slabs in tomographic studies, yet a unifying explanation for their distribution has not been agreed upon. In South America two such anomalies have been imaged associated with subduction of the Nazca Ridge in Peru and the Juan Fernández Ridge in Chile. Here we present new seismic images of the subslab slow velocity anomaly beneath Chile, which give a unique view of the nature of such anomalies. Slow seismic velocities within a large hole in the subducted Nazca slab connect with a subslab slow anomaly that appears correlated with the extent of the subducted Juan Fernández Ridge. The hole in the slab may allow the subslab material to rise into the mantle wedge, revealing the positive buoyancy of the slow material. We propose a new model for subslab slow velocity anomalies beneath the Nazca slab related to the entrainment of hot spot material.

  17. Native American Entrepreneurship. Digest.

    Science.gov (United States)

    Seymour, Nicole

    Although Native Americans have owned and started the fewest small businesses of all U.S. minority groups, entrepreneurship is considered to be an efficient tool for alleviating their economic problems. Barriers to Native American entrepreneurship include poverty, scarce start-up capital, poor access to business education and technical assistance,…

  18. Lithospheric structure beneath the northeastern Tibetan Plateau and the western Sino-Korea Craton revealed by Rayleigh wave tomography

    Science.gov (United States)

    Li, Yonghua; Pan, Jiatie; Wu, Qingju; Ding, Zhifeng

    2017-08-01

    A new 3-D shear wave velocity model of the northeastern (NE) Tibetan Plateau and western Sino-Korea Craton is presented. The model is based on Rayleigh waves recorded at 650 portable stations deployed in the region. Interstation phase and group velocity dispersions for more than 18 000 paths were estimated using the two-station method and then inverted to produce phase velocity maps for 10-80 s period and group velocity maps for 10-60 s period. Local 1-D shear wave velocity profiles for each 0.5° × 0.5°grid node were obtained by inverting Rayleigh wave dispersions obtained in this study together with previously published Rayleigh wave group velocities between 60 and 145 s and then assembled into a 3-D shear wave velocity model. The images obtained reveal an obvious mid-crustal low-velocity zone (LVZ) and low-velocity anomaly in the upper mantle beneath the Songpan-Ganzi terrane. The mid-crustal LVZ can be explained by the presence of partial melting, most likely from asthenospheric upwelling. The existence of a relatively weak mid-crustal LVZ beneath the Qilian orogeny is also confirmed. This LVZ is likely caused by the presence of deep crustal fluids. The Yinchuan-Hetao graben is characterized by relatively low velocities that extend to at least 200 km below the Earth's surface, strongly contrasting with the seismically fast lithosphere of the Ordos and Alax blocks. The model presented here shows the presence of a relatively thick and high-velocity lithosphere beneath the Ordos and NE Alxa blocks, as well as evidence of thinning of the lithosphere beneath the southwestern Alxa and Qilian blocks, indicating that the Alxa block is not subducting beneath NE Tibet.

  19. Crustal Structure Beneath India and Tibet: New Constraints From Inversion of Receiver Functions

    Science.gov (United States)

    Singh, Arun; Ravi Kumar, M.; Mohanty, Debasis D.; Singh, Chandrani; Biswas, Rahul; Srinagesh, D.

    2017-10-01

    The Indian subcontinent comprises geological terranes of varied age and structural character. In this study, we provide new constraints to existing crustal models by inverting the P-to-s receiver functions (RFs) at 317 broadband seismic stations. Inversion results fill crucial gaps in existing velocity models (CRUST1.0 and SEAPS) by capturing regions which are less represented. The final model produced is much more heterogeneous and is able to capture the structural variations between closely spaced seismic stations. In comparison to the global models, major differences are seen for seismic stations located over various rift zones (e.g., Godavari, Narmada, and Cambay) and those close to the coastal regions where transition from oceanic to continental crust is expected to create drastic changes in the crustal configuration. Seismic images are produced along various profiles using 49,682 individual RFs recorded at 442 seismic stations. Lateral variations captured using migrated images across the Himalayan collisional front revealed the hitherto elusive southern extent of the Moho and intracrustal features south of the Main Central Thrust (MCT). Poisson's ratio and crustal thickness estimates obtained using H-k stacking technique and inversion of RFs are grossly similar lending credence to the robustness of inversions. An updated crustal thickness map produced using 1,525 individual data points from controlled source seismics and RFs reveals a (a) thickened crust (>55 km) at the boundary of Dharwar Craton and Southern Granulite Terrain, (b) clear difference in crustal thickness estimates between Eastern Dharwar Craton and Western Dharwar Craton, (c) thinner crust beneath Cambay Basin between southwest Deccan Volcanic Province and Delhi-Aravalli Fold Belt, (d) thinner crust (40 km) beneath paleorift zones like Narmada Son Lineament and Godavari Graben, and (f) very thick crust beneath central Tibet (>65 km) with maximum lateral variations along the Himalayan collision

  20. Project Skippy explores the lithosphere and mantle beneath Australia

    NARCIS (Netherlands)

    Hilst, R.D. van der; Kennett, Brian; Christie, Doug; Grant, John

    1994-01-01

    A new project is probing the seismic structure of the lithosphere and mantle beneath Australia. The Skippy Project, named after the bush kangaroo, exploits Australia's regional seismicity and makes use of recent advances in digital recording technology to collect three-component broadband

  1. Deep structure beneath Lake Ontario: Crustal-scale Grenville subdivisions

    Science.gov (United States)

    Forsyth, D. A.; Milkereit, B.; Zelt, Colin A.; White, D. J.; Easton, R. M.; Hutchinson, Deborah R.

    1994-01-01

    Lake Ontario marine seismic data reveal major Grenville crustal subdivisions beneath central and southern Lake Ontario separated by interpreted shear zones that extend to the lower crust. A shear zone bounded transition between the Elzevir and Frontenac terranes exposed north of Lake Ontario is linked to a seismically defined shear zone beneath central Lake Ontario by prominent aeromagnetic and gravity anomalies, easterly dipping wide-angle reflections, and fractures in Paleozoic strata. We suggest the central Lake Ontario zone represents crustal-scale deformation along an Elzevir–Frontenac boundary zone that extends from outcrop to the south shore of Lake Ontario.Seismic images from Lake Ontario and the exposed western Central Metasedimentary Belt are dominated by crustal-scale shear zones and reflection geometries featuring arcuate reflections truncated at their bases by apparent east-dipping linear reflections. The images show that zones analogous to the interpreted Grenville Front Tectonic Zone are also present within the Central Metasedimentary Belt and support models of northwest-directed crustal shortening for Grenvillian deep crustal deformation beneath most of southeastern Ontario.A Precambrian basement high, the Iroquoian high, is defined by a thinning of generally horizontal Paleozoic strata over a crestal area above the basement shear zone beneath central Lake Ontario. The Iroquoian high helps explain the peninsular extension into Lake Ontario forming Prince Edward County, the occurrence of Precambrian inlier outcrops in Prince Edward County, and Paleozoic fractures forming the Clarendon–Linden structure in New York.

  2. Living and Working Beneath the Sea – Next Approach

    Directory of Open Access Journals (Sweden)

    Rowiński Lech

    2017-04-01

    Full Text Available The idea of living beneath the sea is very new if compared with millennia of shipping activity. In fact, ocean surface was considered mainly as medium suitable for transport of persons and goods as well as aggression and robbery. More practical attempts to live “on” the water surface are limited to well protected internal waters.

  3. Simulation of Wave-Plus-Current Scour beneath Submarine Pipelines

    DEFF Research Database (Denmark)

    Eltard-Larsen, Bjarke; Fuhrman, David R.; Sumer, B. Mutlu

    2016-01-01

    A fully coupled hydrodynamic and morphologic numerical model was utilized for the simulation of wave-plus-current scour beneath submarine pipelines. The model was based on incompressible Reynolds-averaged Navier–Stokes equations, coupled with k-ω turbulence closure, with additional bed and suspen...

  4. Mantle transition zone discontinuities beneath the Tien Shan

    Science.gov (United States)

    Yu, Youqiang; Zhao, Dapeng; Lei, Jianshe

    2017-10-01

    To better understand geodynamic processes of intracontinental mountain building, we conduct a systematic investigation of the mantle transition zone (MTZ) beneath the Tien Shan and its surrounding areas using a receiver function method under non-plane wave front assumption. The resulting apparent depths of the 410 km (d410) and 660 km (d660) discontinuities and the MTZ thickness display significant lateral variations. Both the central Tien Shan and the Pamir Plateau are characterized by a thick MTZ, which can be well explained by the existence of lithospheric segments resulted from possible break-off of the subducted slab or lithosphere delamination. A thin MTZ and an obviously depressed d410, which may be induced by asthenosphere upwelling associated with the dropping lithospheric segment, are revealed beneath the Kazakh Shield. Seismic evidence is obtained for the potential existence of lower mantle upwelling beneath the Tarim Basin based on the observed thin MTZ and relatively significant uplift of d660. The subduction of the Kazakh Shield and Tarim lithosphere driven by the India-Eurasia collision possibly plays an essential role in the formation and evolution of the Tien Shan orogenic belt, and the lower mantle upwelling revealed beneath the Tarim Basin may promote the uplift of the Tien Shan by softening the upper mantle.

  5. Deep long-period earthquakes beneath Washington and Oregon volcanoes

    Science.gov (United States)

    Nichols, M.L.; Malone, S.D.; Moran, S.C.; Thelen, W.A.; Vidale, J.E.

    2011-01-01

    Deep long-period (DLP) earthquakes are an enigmatic type of seismicity occurring near or beneath volcanoes. They are commonly associated with the presence of magma, and found in some cases to correlate with eruptive activity. To more thoroughly understand and characterize DLP occurrence near volcanoes in Washington and Oregon, we systematically searched the Pacific Northwest Seismic Network (PNSN) triggered earthquake catalog for DLPs occurring between 1980 (when PNSN began collecting digital data) and October 2009. Through our analysis we identified 60 DLPs beneath six Cascade volcanic centers. No DLPs were associated with volcanic activity, including the 1980-1986 and 2004-2008 eruptions at Mount St. Helens. More than half of the events occurred near Mount Baker, where the background flux of magmatic gases is greatest among Washington and Oregon volcanoes. The six volcanoes with DLPs (counts in parentheses) are Mount Baker (31), Glacier Peak (9), Mount Rainier (9), Mount St. Helens (9), Three Sisters (1), and Crater Lake (1). No DLPs were identified beneath Mount Adams, Mount Hood, Mount Jefferson, or Newberry Volcano, although (except at Hood) that may be due in part to poorer network coverage. In cases where the DLPs do not occur directly beneath the volcanic edifice, the locations coincide with large structural faults that extend into the deep crust. Our observations suggest the occurrence of DLPs in these areas could represent fluid and/or magma transport along pre-existing tectonic structures in the middle crust. ?? 2010 Elsevier B.V.

  6. Stuck Schools Revisited: Beneath the Averages. K-12 Policy

    Science.gov (United States)

    Ushomirsky, Natasha

    2011-01-01

    "Stuck Schools Revisited: Beneath the Averages" shows why a national focus on turning around the lowest performing schools, while needed, is not enough to raise achievement and close gaps. The report analyzes student achievement data from Maryland and Indiana, which reflect the outcomes seen in other states. The results confirm a…

  7. Thin lithosphere-asthenosphere boundary beneath Eastern Indian craton

    Science.gov (United States)

    Shalivahan; Bhattacharya, Bimalendu B.; Rao, N. V. Chalapathi; Maurya, V. P.

    2014-02-01

    The lithosphere-asthenosphere boundary (LAB) separates the hard and rigid outer layer of the earth (lithosphere) and the weaker, hotter, and deeper part of the upper mantle (asthenosphere) and plays a pivotal role in plate tectonics. However, its definitive detection, especially beneath the cratons, is proving elusive. One of the geophysical tools used to map the LAB beneath the cratons is through magnetotelluric (MT) observations. The resistivity at boundary falls in the range of 5-25 Ω-m and can be explained by the presence of a small amount of water in the asthenosphere, possibly inducing partial melt. Here, we report thickness of the LAB in one of the oldest dated ancient cratons of India-Eastern Indian Craton (EIC) of ~ 3.3 Gyr, from MT studies. The two prominent phase-sensitive strike directions, one each for crust and mantle, and the presence of resistive continental lower crust act as a window to mantle in resolving deeper electrical conductivity structures beneath EIC. Our results show that the LAB beneath the EIC is at 95 km. The region is interesting as the electrical properties of the crust and mantle and the Moho depth are similar to those of the Slave Craton, Canada (~ 4.0 Gyr) but the depth of the LAB beneath the EIC is half that of the Slave craton. As cratonic signatures, depicted by ultrapotassic rocks from Gondwana coal fields close to EIC, are preserved at least till early Cretaceous (117 Ma) it is likely that Himalayan orogeny could have played a major role in delamination of the lithospheric roots of the EIC in addition to attendant seismicity.

  8. Three-dimensional shallow velocity structure beneath Taal Volcano, Philippines

    Science.gov (United States)

    You, Shuei-Huei; Konstantinou, Konstantinos I.; Gung, Yuancheng; Lin, Cheng-Horng

    2017-11-01

    Based on its numerous historical explosive eruptions and high potential hazards to nearby population of millions, Taal Volcano is one of the most dangerous "Decade Volcanoes" in the world. To provide better investigation on local seismicity and seismic structure beneath Taal Volcano, we deployed a temporary seismic network consisting of eight stations from March 2008 to March 2010. In the preliminary data processing stage, three periods showing linear time-drifting of internal clock were clearly identified from noise-derived empirical Green's functions. The time-drifting errors were corrected prior to further data analyses. By using VELEST, 2274 local earthquakes were manually picked and located. Two major earthquake groups are noticed, with one lying beneath the western shore of Taal Lake showing a linear feature, and the other spreading around the eastern flank of Taal Volcano Island at shallower depths. We performed seismic tomography to image the 3D structure beneath Taal Volcano using the LOTOS algorithm. Some interesting features are revealed from the tomographic results, including a solidified magma conduit below the northwestern corner of Taal Volcano Island, indicated by high Vp, Vs, and low Vp/Vs ratio, and a large potential hydrothermal reservoir beneath the center of Taal Volcano Island, suggested by low Vs and high Vp/Vs ratio. Furthermore, combining earthquake distributions and tomographic images, we suggest potential existence of a hydrothermal reservoir beneath the southwestern corner of Taal Lake, and a fluid conduit extending to the northwest. These seismic features have never been proposed in previous studies, implying that new hydrothermal activity might be formed in places away from the historical craters on Taal Volcano Island.

  9. Modelling the Crust beneath the Kashmir valley in Northwestern Himalaya

    Science.gov (United States)

    Mir, R. R.; Parvez, I. A.; Gaur, V. K.; A.; Chandra, R.; Romshoo, S. A.

    2015-12-01

    We investigate the crustal structure beneath five broadband seismic stations in the NW-SE trendingoval shaped Kashmir valley sandwiched between the Zanskar and the Pir Panjal ranges of thenorthwestern Himalaya. Three of these sites were located along the southwestern edge of the valley andthe other two adjoined the southeastern. Receiver Functions (RFs) at these sites were calculated usingthe iterative time domain deconvolution method and jointly inverted with surface wave dispersiondata to estimate the shear wave velocity structure beneath each station. To further test the results ofinversion, we applied forward modelling by dividing the crust beneath each station into 4-6homogeneous, isotropic layers. Moho depths were separately calculated at different piercing pointsfrom the inversion of only a few stacked receiver functions of high quality around each piercing point.These uncertainties were further reduced to ±2 km by trial forward modelling as Moho depths werevaried over a range of ±6 km in steps of 2 km and the synthetic receiver functions matched with theinverted ones. The final values were also found to be close to those independently estimated using theH-K stacks. The Moho depths on the eastern edge of the valley and at piercing points in itssouthwestern half are close to 55 km, but increase to about 58 km on the eastern edge, suggesting thathere, as in the central and Nepal Himalaya, the Indian plate dips northeastwards beneath the Himalaya.We also calculated the Vp/Vs ratio beneath these 5 stations which were found to lie between 1.7 and1.76, yielding a Poisson's ratio of ~0.25 which is characteristic of a felsic composition.

  10. Window into the Caledonian orogen: Structure of the crust beneath the East Shetland platform, United Kingdom

    Science.gov (United States)

    McBride, J.H.; England, R.W.

    1999-01-01

    Reprocessing and interpretation of commercial and deep seismic reflection data across the East Shetland platform and its North Sea margin provide a new view of crustal subbasement structure beneath a poorly known region of the British Caledonian orogen. The East Shetland platform, east of the Great Glen strike-slip fault system, is one of the few areas of the offshore British Caledonides that remained relatively insulated from the Mesozoic and later rifting that involved much of the area around the British Isles, thus providing an "acoustic window" into the deep structure of the orogen. Interpretation of the reflection data suggests that the crust beneath the platform retains a significant amount of its original Caledonian and older architecture. The upper to middle crust is typically poorly reflective except for individual prominent dipping reflectors with complex orientations that decrease in dip with depth and merge with a lower crustal layer of high reflectivity. The three-dimensional structural orientation of the reflectors beneath the East Shetland platform is at variance with Caledonian reflector trends observed elsewhere in the Caledonian orogen (e.g., north of the Scottish mainland), emphasizing the unique tectonic character of this part of the orogen. Upper to middle crustal reflectors are interpreted as Caledonian or older thrust surfaces that were possibly reactivated by Devonian extension associated with post-Caledonian orogenic collapse. The appearance of two levels of uneven and diffractive (i.e., corrugated) reflectivity in the lower crust, best developed on east-west-oriented profiles, is characteristic of the East Shetland platform. However, a north-south-oriented profile reveals an interpreted south-vergent folded and imbricated thrust structure in the lower crust that appears to be tied to the two levels of corrugated reflectivity on the east-west profiles. A thrust-belt origin for lower crustal reflectivity would explain its corrugated

  11. Native listening: The flexibility dimension

    NARCIS (Netherlands)

    Cutler, A.

    2012-01-01

    The way we listen to spoken language is tailored to the specific benefit of native-language speech input. Listening to speech in non-native languages can be significantly hindered by this native bias. Is it possible to determine the degree to which a listener is listening in a native-like manner?

  12. Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau

    Science.gov (United States)

    Li, Guohui; Bai, Ling; Zhou, Yuanze; Wang, Xiaoran; Cui, Qinghui

    2017-11-01

    P-wave triplications related to the 410 km discontinuity (the 410) were clearly observed from the vertical component seismograms of three intermediate-depth earthquakes that occurred in the Indo-Burma Subduction Zone (IBSZ) and were recorded by the Chinese Digital Seismic Network (CDSN). By matching the observed P-wave triplications with synthetics through a grid search, we obtained the best-fit models for four azimuthal profiles (I-IV from north to south) to constrain the P-wave velocity structure near the 410 beneath the southeastern margin of the Tibetan Plateau (TP). A ubiquitous low-velocity layer (LVL) resides atop the mantle transition zone (MTZ). The LVL is 25 to 40 km thick, with a P-wave velocity decrement ranging from approximately - 5.3% to - 3.6% related to the standard Earth model IASP91. An abrupt transition in the velocity decrement of the LVL was observed between profiles II and III. We postulate that the mantle structure beneath the southeastern margin of the TP is primarily controlled by the southeastern extrusion of the TP to the north combined with the eastward subduction of the Indian plate to the south, but not affected by the Emeishan mantle plume. We attribute the LVL to the partial melting induced by water and/or other volatiles released from the subducted Indian plate and the stagnant Pacific plate, but not from the upwelling or the remnants of the Emeishan mantle plume. A high-velocity anomaly ranging from approximately 1.0% to 1.5% was also detected at a depth of 542 to 600 km, providing additional evidence for the remnants of the subducted Pacific plate within the MTZ.

  13. Crawling beneath the free surface: Water snail locomotion

    OpenAIRE

    Lee, Sungyon; Bush, John W. M.; Hosoi, A. E.; Lauga, Eric

    2008-01-01

    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being g...

  14. On Irrotational Flows Beneath Periodic Traveling Equatorial Waves

    Science.gov (United States)

    Quirchmayr, Ronald

    2017-06-01

    We discuss some aspects of the velocity field and particle trajectories beneath periodic traveling equatorial surface waves over a flat bed in a flow with uniform underlying currents. The system under study consists of the governing equations for equatorial ocean waves within a non-inertial frame of reference, where Euler's equation of motion has to be suitably adjusted, in order to account for the influence of the earth's rotation.

  15. The extent of continental crust beneath the Seychelles

    Science.gov (United States)

    Hammond, J. O. S.; Kendall, J.-M.; Collier, J. S.; Rümpker, G.

    2013-11-01

    The granitic islands of the Seychelles Plateau have long been recognised to overlie continental crust, isolated from Madagascar and India during the formation of the Indian Ocean. However, to date the extent of continental crust beneath the Seychelles region remains unknown. This is particularly true beneath the Mascarene Basin between the Seychelles Plateau and Madagascar and beneath the Amirante Arc. Constraining the size and shape of the Seychelles continental fragment is needed for accurate plate reconstructions of the breakup of Gondwana and has implications for the processes of continental breakup in general. Here we present new estimates of crustal thickness and VP/VS from H-κ stacking of receiver functions from a year long deployment of seismic stations across the Seychelles covering the topographic plateau, the Amirante Ridge and the northern Mascarene Basin. These results, combined with gravity modelling of historical ship track data, confirm that continental crust is present beneath the Seychelles Plateau. This is ˜30-33 km thick, but with a relatively high velocity lower crustal layer. This layer thins southwards from ˜10 km to ˜1 km over a distance of ˜50 km, which is consistent with the Seychelles being at the edge of the Deccan plume prior to its separation from India. In contrast, the majority of the Seychelles Islands away from the topographic plateau show no direct evidence for continental crust. The exception to this is the island of Desroche on the northern Amirante Ridge, where thicker low density crust, consistent with a block of continental material is present. We suggest that the northern Amirantes are likely continental in nature and that small fragments of continental material are a common feature of plume affected continental breakup.

  16. Tomographic Inversion for Shear Velocity Beneath the North American Plate

    Science.gov (United States)

    Grand, Stephen P.

    1987-12-01

    A tomographic back projection scheme has been applied to S and SS travel times to invert for shear velocity below the North American plate. The data range in distance from 8° to 80°, and a total of 3923 arrival times were used. First arrivals were measured directly off the seismograms, while the arrival times of later arrivals were found by a waveform correlation technique using synthetic seismograms. The starting model was laterally heterogeneous in the upper 400 km to account for the first-order differences in ray paths already known. The model was divided into blocks with horizontal dimensions of 500 km by 500 km and varying vertical thicknesses. Good resolution was obtained for structure from just below the crust to about 1700 km depth in the mantle. In the upper mantle a high-velocity root was found directly beneath the Canadian shield to about 400 km depth with the Superior province having the highest velocity and deepest root. The east coast of the United States was found to have intermediate velocities from 100 to 350 km depth and the western United States the slowest velocities at these depths. Below 400 km depth the most significant structure found is a slab-shaped high-velocity anomaly from the eastern Carribean to the northern United States. Beneath the Carribean this anomaly is almost vertical and extends from about 700 km to 1700 km depth. Further to the north, the anomaly dips to the east with high velocities at 700 km depth in the central United States and high velocities below 1100 km depth beneath the east coast. The anomaly is about 1% in magnitude. This lower-mantle anomaly may be associated with past subduction of the Farallon plate beneath North America.

  17. Lithospheric radial anisotropy beneath the Gulf of Mexico

    Science.gov (United States)

    Chu, Risheng; Ko, Justin Yen-Ting; Wei, Shengji; Zhan, Zhongwen; Helmberger, Don

    2017-05-01

    The Lithosphere-Asthenosphere Boundary (LAB), where a layer of low viscosity asthenosphere decouples with the upper plate motion, plays an essential role in plate tectonics. Most dynamic modeling assumes that the shear velocity can be used as a surrogate for viscosity which provides key information about mantle flow. Here, we derive a shear velocity model for the LAB structure beneath the Gulf of Mexico allowing a detailed comparison with that beneath the Pacific (PAC) and Atlantic (ATL). Our study takes advantage of the USArray data from the March 25th, 2013 Guatemala earthquake at a depth of 200 km. Such data is unique in that we can observe a direct upward traveling lid arrival which remains the first arrival ahead of the triplications beyond 18°. This extra feature in conjunction with upper-mantle triplication sampling allows good depth control of the LAB and a new upper-mantle seismic model ATM, a modification of ATL, to be developed. ATM has a prominent low velocity zone similar to the structure beneath the western Atlantic. The model contains strong radial anisotropy in the lid where VSH is about 6% faster than VSV. This anisotropic feature ends at the bottom of the lithosphere at about the depth of 175 km in contrast to the Pacific where it extends to over 300 km. Another important feature of ATM is the weaker velocity gradient from the depth of 175 to 350 km compared to Pacific models, which may be related to differences in mantle flow.

  18. Why are there few seedlings beneath the myrmecophyte Triplaris americana?

    Science.gov (United States)

    Larrea-Alcázar, Daniel M.; Simonetti, Javier A.

    2007-07-01

    We compared the relative importance of chemical alellopathy, pruning behaviour of resident ants and other non-related agents to ant-plant mutualism for seedling establishment beneath Triplaris americana L. (Polygonaceae), a myrmecophyte plant. We also included a preliminary analysis of effects of fragmentation on these ecological processes. Seeds and seedlings of Theobroma cacao L. (Sterculiaceae) were used as the target species in all experiments. Leaf-tissue extracts of the myrmecophyte plant did not inhibit germination of cacao seeds. Resident Pseudomyrmex triplarinus Weddell (Pseudomyrmecinae) ants did not remove seeds under the canopy of their host plants. The main seed consumer was the leaf-cutting ant Atta sexdens L. (Myrmicinae). Leaves of cacao seedlings were partially or totally pruned by Pseudomyrmex ants mainly in forest fragments studied. We offer evidence pointing to the possibility that the absence of seedlings beneath Triplaris may result from effects of both ant species. We discuss the benefits of pruning behaviour for the resident ant colony and the effects of ant-ant interactions on seedling establishment beneath this ant-plant system.

  19. Native fruit traits may mediate dispersal competition between native and non-native plants

    Directory of Open Access Journals (Sweden)

    Clare Aslan

    2012-02-01

    Full Text Available Seed disperser preferences may mediate the impact of invasive, non-native plant species on their new ecological communities. Significant seed disperser preference for invasives over native species could facilitate the spread of the invasives while impeding native plant dispersal. Such competition for dispersers could negatively impact the fitness of some native plants. Here, we review published literature to identify circumstances under which preference for non-native fruits occurs. The importance of fruit attraction is underscored by several studies demonstrating that invasive, fleshy-fruited plant species are particularly attractive to regional frugivores. A small set of studies directly compare frugivore preference for native vs. invasive species, and we find that different designs and goals within such studies frequently yield contrasting results. When similar native and non-native plant species have been compared, frugivores have tended to show preference for the non-natives. This preference appears to stem from enhanced feeding efficiency or accessibility associated with the non-native fruits. On the other hand, studies examining preference within existing suites of co-occurring species, with no attempt to maximize fruit similarity, show mixed results, with frugivores in most cases acting opportunistically or preferring native species. A simple, exploratory meta-analysis finds significant preference for native species when these studies are examined as a group. We illustrate the contrasting findings typical of these two approaches with results from two small-scale aviary experiments we conducted to determine preference by frugivorous bird species in northern California. In these case studies, native birds preferred the native fruit species as long as it was dissimilar from non-native fruits, while non-native European starlings preferred non-native fruit. However, native birds showed slight, non-significant preference for non-native fruit

  20. Immigrants and Native Workers

    DEFF Research Database (Denmark)

    Foged, Mette; Peri, Giovanni

    Using a database that includes the universe of individuals and establishments in Denmark over the period 1991-2008 we analyze the effect of a large inflow of non-European (EU) immigrants on Danish workers. We first identify a sharp and sustained supply-driven increase in the inflow of non......-EU immigrants in Denmark, beginning in 1995 and driven by a sequence of international events such as the Bosnian, Somalian and Iraqi crises. We then look at the response of occupational complexity, job upgrading and downgrading, wage and employment of natives in the short and long run. We find...... that the increased supply of non-EU low skilled immigrants pushed native workers to pursue more complex occupations. This reallocation happened mainly through movement across firms. Immigration increased mobility of natives across firms and across municipalities but it did not increase their probability...

  1. Electrical resistivity dynamics beneath a fractured sedimentary bedrock riverbed in response to temperature and groundwater-surface water exchange

    Science.gov (United States)

    Steelman, Colby M.; Kennedy, Celia S.; Capes, Donovan C.; Parker, Beth L.

    2017-06-01

    Bedrock rivers occur where surface water flows along an exposed rock surface. Fractured sedimentary bedrock can exhibit variable groundwater residence times, anisotropic flow paths, and heterogeneity, along with diffusive exchange between fractures and rock matrix. These properties of the rock will affect thermal transients in the riverbed and groundwater-surface water exchange. In this study, surface electrical methods were used as a non-invasive technique to assess the scale and temporal variability of riverbed temperature and groundwater-surface water interaction beneath a sedimentary bedrock riverbed. Conditions were monitored at a semi-daily to semi-weekly interval over a full annual period that included a seasonal freeze-thaw cycle. Surface electromagnetic induction (EMI) and electrical resistivity tomography (ERT) methods captured conditions beneath the riverbed along a pool-riffle sequence of the Eramosa River in Canada. Geophysical datasets were accompanied by continuous measurements of aqueous specific conductance, temperature, and river stage. Time-lapse vertical temperature trolling within a lined borehole adjacent to the river revealed active groundwater flow zones along fracture networks within the upper 10 m of rock. EMI measurements collected during cooler high-flow and warmer low-flow periods identified a spatiotemporal riverbed response that was largely dependent upon riverbed morphology and seasonal groundwater temperature. Time-lapse ERT profiles across the pool and riffle sequence identified seasonal transients within the upper 2 and 3 m of rock, respectively, with spatial variations controlled by riverbed morphology (pool versus riffle) and dominant surficial rock properties (competent versus weathered rock rubble surface). While the pool and riffle both exhibited a dynamic resistivity through seasonal cooling and warming cycles, conditions beneath the pool were more variable, largely due to the formation of river ice during the winter season

  2. Understanding the nature of mantle upwelling beneath East-Africa

    Science.gov (United States)

    Civiero, Chiara; Hammond, James; Goes, Saskia; Ahmed, Abdulhakim; Ayele, Atalay; Doubre, Cecile; Goitom, Berhe; Keir, Derek; Kendall, Mike; Leroy, Sylvie; Ogubazghi, Ghebrebrhan; Rumpker, Georg; Stuart, Graham

    2014-05-01

    The concept of hot upwelling material - otherwise known as mantle plumes - has long been accepted as a possible mechanism to explain hotspots occurring at Earth's surface and it is recognized as a way of removing heat from the deep Earth. Nevertheless, this theory remains controversial since no one has definitively imaged a plume and over the last decades several other potential mechanisms that do not require a deep mantle source have been invoked to explain this phenomenon, for example small-scale convection at rifted margins, meteorite impacts or lithospheric delamination. One of the best locations to study the potential connection between hotspot volcanism at the surface and deep mantle plumes on land is the East African Rift (EAR). We image seismic velocity structure of the mantle below EAR with higher resolution than has been available to date by including seismic data recorded by stations from many regional networks ranging from Saudi Arabia to Tanzania. We use relative travel-time tomography to produce P- velocity models from the surface down into the lower mantle incorporating 9250 ray-paths in our model from 495 events and 402 stations. We add smaller earthquakes (4.5 image structures of ~ 100-km length scales to ~ 1000 km depth beneath the northern East-Africa rift (Ethiopia, Eritrea, Djibouti, Yemen) with good resolution also in the transition zone and uppermost lower mantle. Our observations provide evidence that the shallow mantle slow seismic velocities continue trough the transition zone and into the lower mantle. In particular, the relatively slow velocity anomaly beneath the Afar Depression extends up to depths of at least 1000 km depth while another low-velocity anomaly beneath the Main Ethiopian Rift seems to be present in the upper mantle only. These features in the lower mantle are isolated with a diameter of about 400 km indicating deep multiple sources of upwelling that converge in broader low-velocity bodies along the rift axis at shallow

  3. Food sources of dominant macrozoobenthos between native and non-native mangrove forests: A comparative study

    Science.gov (United States)

    Chen, Luzhen; Yan, Ting; Xiong, Yiyi; Zhang, Yihui; Lin, Guanghui

    2017-03-01

    The macrozoobenthos is an important link of the food web in coastal wetlands. Diet-habitat relationships may significantly depend on qualitative differences and seasonal availability of food sources. Increasing interest has been shown in food web structure altered by non-native plants. In particular, however, a non-native mangrove species from Bangladesh, Sonneratia apetala, has been widely planted in China, but little is known about its possible impact on food sources of macrozoobenthos living in these non-native mangrove forests. Therefore, in this study, we used fatty acid analysis to compare the food sources of one littorinid snail and two grapsid crab species between two native mangrove forests and one non-native S. apetala plantation in the Zhanjiang Mangrove National Nature Reserve of China. We found that the sediment of all three forests had high diatom and bacteria signals, but low mangrove leaf signals, while the opposite patterns were detected in the three macrozoobenthos. Specifically, the gastropod Littoraria melanostoma relied mainly on mangrove leaves and brown algae as food sources, with significant differences among the three mangrove forests, and showed significant seasonal variation in its diet. The grapsidae species (Perisesarma bidens and Parasesarma plicatum) mainly grazed on mangrove litter, brown and green algae, and occasionally consumed diatoms and bacteria, also showing significant seasonal variation in their diet. Overall, Principle Components Analysis (PCA) of the fatty acid profiles showed a significant overlapping in food sources among the macrozoobenthos living in the non-native and native mangrove forests, but significant seasonal variations in their food sources. This suggests that the planting of non-native S. apetala near original mangrove forests has had little effect on the feeding behavior of macrozoobenthos some 10 years after planting.

  4. Native American Health

    Science.gov (United States)

    Every racial or ethnic group has specific health concerns. Differences in the health of groups can result from: Genetics Environmental factors Access to care Cultural factors On this page, you'll find links to health issues that affect Native Americans.

  5. Native American Nuances.

    Science.gov (United States)

    Evensen, Helen

    1998-01-01

    Continues a series of articles on art projects incorporating the use of alphabetical or numerical symbols. Describes a project in which third-grade students incorporated Native American art motifs and symbols into large-scale paintings of letters of the alphabet. Notes discoveries made by students in the course of their projects. (DSK)

  6. Insights towards Native and Non-Native ELT Educators

    OpenAIRE

    Villalobos Ulate, Nuria

    2011-01-01

    A detailed analysis is provided here of the concept, perceptions and attitudes towards native and non-native English speaking teachers. The notion that the ideal language educator is a native speaker is explained and questioned, and examples of the unfair treatment non-native speakers of English sometimes receive are given. The strengths in both NESTs and NNESTs are highlighted. Se analiza el concepto, las percepciones y actitudes de los docentes hablantes nativos y no nativos del inglés. ...

  7. A Low-velocity Finger from Iceland beneath Southern Scandinavia - the Key to Understanding Neogene Uplift?

    Science.gov (United States)

    Weidle, C.; Maupin, V.

    2007-12-01

    A model of upper mantle S-wave velocity beneath northwestern Europe is presented, based on a tomography of regional surface wave observations. Data from international and, more importantly, regional data archives (including temporary deployments) were used to measure group velocities for both Love and Rayleigh surface waves. The procedure for data selection, group velocity measurements and inversion for group velocity 2-D maps follows closely the one described by Levshin et al. (GJI, 170, 441-459, 2007). Our new set of group velocity maps differs significantly from global reference maps, enhancing many details and amplitudes of group velocity variations in the study region. We then apply a linear inversion scheme to invert for 1-D shear wave velocity profiles which are assembled to a 3-D model. By choosing conservative regularization parameters in the 2-D inversion we ensure the smoothness of the group velocity maps and the resulting 3-D shear wave speed model. To account for the different tectonic regimes in the study region, we compare inversions with 3 different reference models (pure 1-D, 3-D crust / 1-D mantle and pure 3-D) to investigate the sensitivity of the 1-D inversions to inaccuracies in crustal models. We find that all three models are consistent at depths below 90 km and the resulting models deviate only slightly from each other, mostly in amplitudes. We image an intriguing low-velocity anomaly extending from the Iceland plume domain across the north Atlantic beneath southern Scandinavia between 70-150 km depth. Beneath southern Norway, the negative perturbations reach a maximum of up to 13 % w.r.t. ak135 and a shallowing of the anomaly is indicated. This observation could explain the sustained uplift of southern Scandinavia in Neogene times, but the mechanisms are yet undetermined. Furthermore, our upper mantle model reveals good alignment to ancient plate boundaries and first-order crustal fronts around the triple junction of the Baltica

  8. A Broad Depressed 410-km Discontinuity beneath Northeast Asia

    Science.gov (United States)

    Li, J.; Guo, G.; WANG, X.

    2016-12-01

    The topography of the upper mantle discontinuities is important for good understanding of the thermal structure, composition of the mantle, and scales of mantle circulation as well. We applied both receiver function analysis and multiple-ScS reverberations to seismic waveforms recorded by stations beneath land and ocean, respectively. We obtained a complete image of the upper mantle discontinuities beneath northeast Asia, covering from the Okhotsk Sea, far east Russia, Japan Sea and northeast China. Results with different resolutions from different methods are compared in detail, and the comparison shows that long-period ScS reverberation signals is effective in extracting the robust features of the upper mantle discontinuities. Through the integrated depth undulation map covering both sea and land, we detected an obvious depression of the 410-km discontinuity with value 8-25 km, anticorrelated with a wide range of depressed 660-km discontinuity. The depression of the 660 can be explained by the temperature anomaly associated to the subducting Pacific slab. The landward extension of the depressed 410, however, is of large scale with a lateral range of at least 800-1000 km. Mechanism invoking chemical heterogeneity in the mantle transition zone was explored to explain the observation. We speculate that the broadly depressed 410 beneath west Japan Sea, part of Okhotsk Sea, and northeast China might be caused by high water content at the top of the mantle transition zone. The significant trench rollback motion of the subducting Pacific slab from the Miocene might explain the widespread distribution of the depression of the 410. The west edge of observed depressed 410-km discontinuity might pin the initial location where the Pacific subducting slab had been furthest before the occurrence of trench retreating.

  9. Mantle structure beneath the Alboran Sea from shear wave splitting

    Science.gov (United States)

    Alpert, L. A.; Becker, T. W.; Miller, M. S.; Allam, A. A.

    2011-12-01

    New seismological investigations in the Alboran domain of the western Mediterranean, as part of the PICASSO experiment, support geodynamic models which constrain the mantle structure beneath the Alboran Sea. We evaluate global circulation models in the context of seismic anistropy as inferred from SKS/SKKS splitting observations. Using instantaneous velocity fields from 3-D flow models with variable mantle density based on several tomography and seismicity based models, we calculate the predicted anisotropy, fast polarization direction (FPD), and delay times in order to explain the complex tectonic and geologic history of the Alboran Sea region. Slab rollback, delamination, and convective removal processes have been invoked to explain the synorogenic extension in the Alboran and recently published splitting measurements show north-east trending FPD across the Iberian margin with a rotation to the southeast that follows the curve of the Gibraltar arc, suggested by the authors as supporting west-directed slab rollback. Our new measurements from 39 stations substantiate the measurements in southern Spain, but we find a striking, nearly 90 degree rotation in azimuth and reduced delay times across the High Atlas Mountains in northern Morocco. These splitting patterns define three distinct regions we attempt to predict with our geodynamic models. Here, we test several differently-oriented subduction, slab break-off, and delamination scenarios. Our preliminary results show that density models which include a curved, northeast trending slab predict the east-northeast oriented measurements along the Iberian margin. Imposing a drip structure beneath the Alboran Sea also predicts these orientations. In order to predict the rotation of the FPD we find in Morocco, however, most models require a stiff keel beneath the African craton.

  10. Intelligibility of native and non-native Dutch Speech

    NARCIS (Netherlands)

    Wijngaarden, S.J. van

    2001-01-01

    The intelligibility of speech is known to be lower if the speaker is non-native instead of native for the given language. This study is aimed at quantifying the overall degradation due to limitations of non-native speakers of Dutch, specifically of Dutch-speaking Americans who have lived in the

  11. Speech intelligibility of native and non-native speech

    NARCIS (Netherlands)

    Wijngaarden, S.J. van

    1999-01-01

    The intelligibility of speech is known to be lower if the talker is non-native instead of native for the given language. This study is aimed at quantifying the overall degradation due to acoustic-phonetic limitations of non-native talkers of Dutch, specifically of Dutch-speaking Americans who have

  12. The structure of the crust and uppermost mantle beneath Madagascar

    Science.gov (United States)

    Andriampenomanana, Fenitra; Nyblade, Andrew A.; Wysession, Michael E.; Durrheim, Raymond J.; Tilmann, Frederik; Julià, Jordi; Pratt, Martin J.; Rambolamanana, Gérard; Aleqabi, Ghassan; Shore, Patrick J.; Rakotondraibe, Tsiriandrimanana

    2017-09-01

    The lithosphere of Madagascar was initially amalgamated during the Pan-African events in the Neoproterozoic. It has subsequently been reshaped by extensional processes associated with the separation from Africa and India in the Jurassic and Cretaceous, respectively, and been subjected to several magmatic events in the late Cretaceous and the Cenozoic. In this study, the crust and uppermost mantle have been investigated to gain insights into the present-day structure and tectonic evolution of Madagascar. We analysed receiver functions, computed from data recorded on 37 broad-band seismic stations, using the H-κ stacking method and a joint inversion with Rayleigh-wave phase-velocity measurements. The thickness of the Malagasy crust ranges between 18 and 46 km. It is generally thick beneath the spine of mountains in the centre part (up to 46 km thick) and decreases in thickness towards the edges of the island. The shallowest Moho is found beneath the western sedimentary basins (18 km thick), which formed during both the Permo-Triassic Karro rifting in Gondwana and the Jurassic rifting of Madagascar from eastern Africa. The crust below the sedimentary basin thickens towards the north and east, reflecting the progressive development of the basins. In contrast, in the east there was no major rifting episode. Instead, the slight thinning of the crust along the east coast (31-36 km thick) may have been caused by crustal uplift and erosion when Madagascar moved over the Marion hotspot and India broke away from it. The parameters describing the crustal structure of Archean and Proterozoic terranes, including average thickness (40 km versus 35 km), Poisson's ratio (0.25 versus 0.26), average shear-wave velocity (both 3.7 km s-1), and thickness of mafic lower crust (7 km versus 4 km), show weak evidence of secular variation. The uppermost mantle beneath Madagascar is generally characterized by shear-wave velocities typical of stable lithosphere (∼4.5 km s-1). However

  13. Native Prairie Adaptive Management (NPAM)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — NPAM is a framework for guiding annual decisions about the management of Service‐owned native prairie parcels that are prone to invasions by non‐native grasses,...

  14. Native Americans' Interest in Horticulture.

    Science.gov (United States)

    Meyer, Mary Hockenberry

    1999-01-01

    Focus groups arranged by local Native American Master Gardeners on two Minnesota reservations determined community interest in extension-horticulture programs. Topics of interest included food preservation and historical Native-American uses of plants. (SK)

  15. New insights on the crustal thickness and its lateral variations beneath the Rif Cordillera

    Science.gov (United States)

    Gil de la Iglesia, A.; Diaz Cusi, J.; Gallart, J.; Carbonell, R.; Harnafi, M.; Levander, A.

    2014-12-01

    The Rif cordillera forms, together with the Betic ranges, one of the tightest orogenic arcs on Earth. This continental boundary zone is dominated now by the slow convergence between Nubia and Eurasia, but with clear evidences of extensional tectonics. One of the missing elements to constrain the complex geodynamics of the Gibraltar Arc System is the knowledge on crustal structure beneath northern Morocco. In the last decade a major effort has been done in this sense, from active and passive seismics. We compile here the recent results available from the Rif domains. Two 330 km long wide angle DSS profiles were recorded end of 2011 across the Rif in NS and EW transects within the Rifsis project, complemented by onshore recordings of the Gassis-WestMed marine profiles. At the same period, BB seismic arrays were deployed in the area within Topo-Iberia and Picasso projects, allowing receiver function analyses of crustal depths. The ray-tracing modeling of the Rifsis profiles reveal a large Moho step and an area of crustal thickening both in EW and NS directions, grossly coincident with the Bouguer gravity anomalies. The deployment logistics allowed that all the stations recorded all the shots, thus providing useful offline data. We will use here all available in-line and offline data to provide a map of the crustal thickness in northern Morocco. We combined two approaches: i) a hyperbolic time reduction applied to the seismic data, resulting in low-fold stacks in which the reflections from the Moho should appear as subhorizontal lines; ii) the arrival times of the observed PmP phases allow, assuming a mean crustal velocity, to assign a midpoint crustal thickness to each lecture. Although some uncertainties may be inherent to those approaches, a large crustal root, reaching more than 50 km, is well documented in the central part of the Rif Cordillera, close to the zone where the Alboran slab may still be attached to the lithosphere. We also compared these results with

  16. Variability of Basal Melt Beneath the Pine Island Glacier Ice Shelf, West Antarctica

    Science.gov (United States)

    Bindschadler, Robert; Vaughan, David G.; Vornberger, Patricia

    2011-01-01

    Observations from satellite and airborne platforms are combined with model calculations to infer the nature and efficiency of basal melting of the Pine Island Glacier ice shelf, West Antarctica, by ocean waters. Satellite imagery shows surface features that suggest ice-shelf-wide changes to the ocean s influence on the ice shelf as the grounding line retreated. Longitudinal profiles of ice surface and bottom elevations are analyzed to reveal a spatially dependent pattern of basal melt with an annual melt flux of 40.5 Gt/a. One profile captures a persistent set of surface waves that correlates with quasi-annual variations of atmospheric forcing of Amundsen Sea circulation patterns, establishing a direct connection between atmospheric variability and sub-ice-shelf melting. Ice surface troughs are hydrostatically compensated by ice-bottom voids up to 150m deep. Voids form dynamically at the grounding line, triggered by enhanced melting when warmer-than-average water arrives. Subsequent enlargement of the voids is thermally inefficient (4% or less) compared with an overall melting efficiency beneath the ice shelf of 22%. Residual warm water is believed to cause three persistent polynyas at the ice-shelf front seen in Landsat imagery. Landsat thermal imagery confirms the occurrence of warm water at the same locations.

  17. Digital Natives or Digital Tribes?

    Science.gov (United States)

    Watson, Ian Robert

    2013-01-01

    This research builds upon the discourse surrounding digital natives. A literature review into the digital native phenomena was undertaken and found that researchers are beginning to identify the digital native as not one cohesive group but of individuals influenced by other factors. Primary research by means of questionnaire survey of technologies…

  18. Complex seismic anisotropy and mantle dynamics beneath Turkey

    Science.gov (United States)

    Lemnifi, Awad A.; Elshaafi, Abdelsalam; Karaoğlu, Özgür; Salah, Mohamed K.; Aouad, Nassib; Reed, Cory A.; Yu, Youqiang

    2017-12-01

    Seismic anisotropy is an unambiguous property of the deep Earth that is often detected through shear wave splitting (SWS) and anisotropic receiver function (RF) techniques, which are then used to infer the lithospheric and asthenospheric deformational structure. The Anatolian plate and its associated Mediterranean, Eurasian, and Arabian plate boundaries represent the consequences of a variety of convergent and transform tectonic regimes; these boundaries are thus well-suited for studying seismic anisotropy related to subduction, orogenic, and strike-slip processes. We apply a joint SWS and RF analysis to identify the magnitude and orientation of deformation associated with lithosphere-asthenosphere coupling beneath the Anatolian plate system as well as intra-plate fossil fabrics resulting from ancient and ongoing collision. SWS analysis reveals the existence of complex anisotropic fabrics beneath the Anatolian region, where the upper-layer fast orientations are either parallel to strike-slip faults or orthogonal to reverse faults. Strongly oriented NE-SW lower-layer fast orientations suggest that they originate from slab-modulated flow in the mantle wedge overlying the northward-subducting African plate. The results of the RF analysis show that the fast orientations are spatially variable but are generally consistent with crustal fabrics developed mostly through intensive faulting and are possibly associated with sub-vertical lower crustal shear zones.

  19. Pervasive upper mantle melting beneath the western US

    Science.gov (United States)

    Hier-Majumder, Saswata; Tauzin, Benoit

    2017-04-01

    We report from converted seismic waves, a pervasive seismically anomalous layer above the transition zone beneath the western US. The layer, characterized by an average shear wave speed reduction of 1.6%, spans over an area of ∼ 1.8 ×106 km2 with thicknesses varying between 25 and 70 km. The location of the layer correlates with the present location of a segment of the Farallon plate. This spatial correlation and the sharp seismic signal atop of the layer indicate that the layer is caused by compositional heterogeneity. Analysis of the seismic signature reveals that the compositional heterogeneity can be ascribed to a small volume of partial melt (0.5 ± 0.2 vol% on average). This article presents the first high resolution map of the melt present within the layer. Despite spatial variations in temperature, the calculated melt volume fraction correlates strongly with the amplitude of P-S conversion throughout the region. Comparing the values of temperature calculated from the seismic signal with available petrological constraints, we infer that melting in the layer is caused by release of volatiles from the subducted Farallon slab. This partially molten zone beneath the western US can sequester at least 1.2 ×1017 kg of volatiles, and can act as a large regional reservoir of volatile species such as H or C.

  20. Azimuthal anisotropy in the D″ layer beneath the Caribbean

    Science.gov (United States)

    Maupin, ValéRie; Garnero, Edward J.; Lay, Thorne; Fouch, Matthew J.

    2005-08-01

    The lowermost mantle beneath Central America has anisotropic seismic velocity structure manifested in shear wave splitting of signals from South American earthquakes recorded at North American broadband recording stations. Prior studies of deep mantle anisotropy in this region have characterized the structure as having vertical transverse isotropy (VTI), which is sufficient to explain a general trend of early tangential (SH) component arrivals. However, VTI models cannot quantitatively match systematic waveform complexities in the onset of many of the shear waves that graze this region. After accounting for splitting effects of upper mantle anisotropy beneath the recording stations, we model the corrected waveform data using full wave theory for mantle velocity models with an anisotropic D″ layer. This is the first attempt to quantitatively model a large data set including azimuthal anisotropy in D″. The models include transverse isotropy with either a vertical or tilted symmetry axis, the latter resulting in azimuthal anisotropy. For some initial shear wave polarizations, tilted transverse isotropy (TTI) produces small, reversed polarity arrivals on the SV components at the arrival time of SH, consistent with the data. Geographical variations in the azimuth of the TTI symmetry axis are indicated by the data. The lack of azimuthal coverage prevents unique resolution of the TTI orientation and also precludes distinguishing between TTI and other azimuthal anisotropy structures such as that predicted for lattice preferred orientation of minerals. Nonetheless, our modeling demonstrates the need for laterally varying anisotropic structure of more complex form than VTI for this region.

  1. Slab melting and magma formation beneath the southern Cascade arc

    Science.gov (United States)

    Walowski, Kristina J.; Wallace, Paul J.; Clynne, Michael A.; Rasmussen, D.J.; Weis, D.

    2016-01-01

    The processes that drive magma formation beneath the Cascade arc and other warm-slab subduction zones have been debated because young oceanic crust is predicted to largely dehydrate beneath the forearc during subduction. In addition, geochemical variability along strike in the Cascades has led to contrasting interpretations about the role of volatiles in magma generation. Here, we focus on the Lassen segment of the Cascade arc, where previous work has demonstrated across-arc geochemical variations related to subduction enrichment, and H-isotope data suggest that H2O in basaltic magmas is derived from the final breakdown of chlorite in the mantle portion of the slab. We use naturally glassy, olivine-hosted melt inclusions (MI) from the tephra deposits of eight primitive (MgO>7 wt%) basaltic cinder cones to quantify the pre-eruptive volatile contents of mantle-derived melts in this region. The melt inclusions have B concentrations and isotope ratios that are similar to mid-ocean ridge basalt (MORB), suggesting extensive dehydration of the downgoing plate prior to reaching sub-arc depths and little input of slab-derived B into the mantle wedge. However, correlations of volatile and trace element ratios (H2O/Ce, Cl/Nb, Sr/Nd) in the melt inclusions demonstrate that geochemical variability is the result of variable addition of a hydrous subduction component to the mantle wedge. Furthermore, correlations between subduction component tracers and radiogenic isotope ratios show that the subduction component has less radiogenic Sr and Pb than the Lassen sub-arc mantle, which can be explained by melting of subducted Gorda MORB beneath the arc. Agreement between pMELTS melting models and melt inclusion volatile, major, and trace element data suggests that hydrous slab melt addition to the mantle wedge can produce the range in primitive compositions erupted in the Lassen region. Our results provide further evidence that chlorite-derived fluids from the mantle portion of the

  2. Seismic tomography reveals magma chamber location beneath Uturuncu volcano (Bolivia)

    Science.gov (United States)

    Kukarina, Ekaterina; West, Michael; Koulakov, Ivan

    2014-05-01

    Uturuncu volcano belongs to the Altiplano-Puna Volcanic Complex in the central Andes, the product of an ignimbrite ''flare-up''. The region has been the site of large-scale silicic magmatism since 10 Ma, producing 10 major eruptive calderas and edifices, some of which are multiple-eruption resurgent complexes as large as the Yellowstone or Long Valley caldera. Satellite measurements show that the hill has been rising more than half an inch a year for almost 20 years, suggesting that the Uturuncu volcano, which has erupted last time more than 300,000 years ago, is steadily inflating, which makes it fertile ground for study. In 2009 an international multidisciplinary team formed a project called PLUTONS to study Uturuncu. Under this project a 100 km wide seismic network was set around the volcano by seismologists from University of Alaska Fairbanks. Local seismicity is well distributed and provides constraints on the shallow crust. Ray paths from earthquakes in the subducting slab complement this with steep ray paths that sample the deeper crust. Together the shallow and deep earthquakes provide strong 3D coverage of Uturuncu and the surrounding region. To study the deformation source beneath the volcano we performed simultaneous tomographic inversion for the Vp and Vs anomalies and source locations, using the non-linear passive source tomographic code, LOTOS. We estimated both P and S wave velocity structures beneath the entire Uturuncu volcano by using arrival times of P and S waves from more than 600 events registered by 33 stations. To show the reliability of the results, we performed a number of different tests, including checkerboard synthetic tests and tests with odd/even data. Obtained Vp/Vs ratio distribution shows increased values beneath the south Uturuncu, at a depth of about 15 km. We suggest the high ratio anomaly is caused by partial melt, presented in expanding magma chamber, responsible for the volcano inflation. The resulting Vp, Vs and the ratio

  3. Estimates of Deep Percolation Beneath Native Vegetation, Irrigated Fields, and The Amargosa-River Channel, Amargosa Desert, Nye County, Nevada

    Science.gov (United States)

    2003-01-01

    appendix A). This material was identified as “Lava Creek B” ash from a caldera eruption in the Yellowstone -Park area about 650,000 years ago (Andrei...identified as the Lava Creek B ash from a caldera eruption in the Yellowstone -Park area about 650,000 19 years ago. This implies that the Amargosa-Farms

  4. Evaluating nurse plants for restoring native woody species to degraded subtropical woodlands.

    Science.gov (United States)

    Yelenik, Stephanie G; DiManno, Nicole; D'Antonio, Carla M

    2015-01-01

    Harsh habitats dominated by invasive species are difficult to restore. Invasive grasses in arid environments slow succession toward more desired composition, yet grass removal exacerbates high light and temperature, making the use of "nurse plants" an appealing strategy. In this study of degraded subtropical woodlands dominated by alien grasses in Hawai'i, we evaluated whether individuals of two native (Dodonaea viscosa, Leptocophylla tameiameia) and one non-native (Morella faya) woody species (1) act as natural nodes of recruitment for native woody species and (2) can be used to enhance survivorship of outplanted native woody species. To address these questions, we quantified the presence and persistence of seedlings naturally recruiting beneath adult nurse shrubs and compared survival and growth of experimentally outplanted seedlings of seven native woody species under the nurse species compared to intact and cleared alien-grass plots. We found that the two native nurse shrubs recruit their own offspring, but do not act as establishment nodes for other species. Morella faya recruited even fewer seedlings than native shrubs. Thus, outplanting will be necessary to increase abundance and diversity of native woody species. Outplant survival was the highest under shrubs compared to away from them with few differences between nurse species. The worst habitat for native seedling survival and growth was within the unmanaged invasive grass matrix. Although the two native nurse species did not differentially affect outplant survival, D. viscosa is the most widespread and easily propagated and is thus more likely to be useful as an initial nurse species. The outplanted species showed variable responses to nurse habitats that we attribute to resource requirements resulting from their typical successional stage and nitrogen fixation capability.

  5. Evaluating nurse plants for restoring native woody species to degraded subtropical woodlands

    Science.gov (United States)

    Yelenik, Stephanie G.; DiManno, Nicole; D’Antonio, Carla M.

    2015-01-01

    Harsh habitats dominated by invasive species are difficult to restore. Invasive grasses in arid environments slow succession toward more desired composition, yet grass removal exacerbates high light and temperature, making the use of “nurse plants” an appealing strategy. In this study of degraded subtropical woodlands dominated by alien grasses in Hawai'i, we evaluated whether individuals of two native (Dodonaea viscosa, Leptocophylla tameiameia) and one non-native (Morella faya) woody species (1) act as natural nodes of recruitment for native woody species and (2) can be used to enhance survivorship of outplanted native woody species. To address these questions, we quantified the presence and persistence of seedlings naturally recruiting beneath adult nurse shrubs and compared survival and growth of experimentally outplanted seedlings of seven native woody species under the nurse species compared to intact and cleared alien-grass plots. We found that the two native nurse shrubs recruit their own offspring, but do not act as establishment nodes for other species. Morella faya recruited even fewer seedlings than native shrubs. Thus, outplanting will be necessary to increase abundance and diversity of native woody species. Outplant survival was the highest under shrubs compared to away from them with few differences between nurse species. The worst habitat for native seedling survival and growth was within the unmanaged invasive grass matrix. Although the two native nurse species did not differentially affect outplant survival, D. viscosa is the most widespread and easily propagated and is thus more likely to be useful as an initial nurse species. The outplanted species showed variable responses to nurse habitats that we attribute to resource requirements resulting from their typical successional stage and nitrogen fixation capability.

  6. NAWIG News: The Quarterly Newsletter of the Native American Wind Interest Group, Spring 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-01-01

    As part of its Native American outreach, DOE's Wind Powering America program has initiated a NAWIG newsletter to present Native American wind information, including projects, interviews with pioneers, issues, WPA activities, and related events. It is our hope that this newsletter will both inform and elicit comments and input on wind development in Indian Country. This issue profiles the Banner Wind Project in Nome, Alaska, and a new Native project in Kansas.

  7. Gravimetric imaging of partially molten bodies beneath the Bolivian Altiplano

    Science.gov (United States)

    del Potro, R.; Diez, M.; Gottsmann, J.; Camacho, A. J.; Sunagua, M.

    2011-12-01

    The presence of partial melt in the Earth's crust causes a decrease in density, and hence a density contrast, that generates a potential field anomaly. Gravimetric techniques can quantify such an anomaly and invert its signature to produce a subsurface density distribution model, from which images of anomalous density bodies can be isolated. Here, we present a 3D gravimetric image of four deep-rooted negative density bodies in the Central Volcanic Zone of the Andes in southern Bolivia, which we interpret to contain partial melt. The underlying gravimetric data were obtained by the combination of 143 new with 60 existing observation from previous regional surveys. The survey covers an area of ~5000 km2 that comprises the Central Andean Bouguer anomaly minima of about -450 μGal. After standard data reduction, the local residual gravity signal was inverted using a priori determined plausible density contrasts (±50 to ±300 kg m-3). The inversion routine builds a subsurface model (defined by the 3D aggregation of parallel-piped cells) based on a controlled 'growth' process of anomalous density bodies by means of an exploratory approach. Non-uniqueness is addressed by favouring solutions that balance minimum residuals and minimum number of anomalous bodies with minimum anomalous mass. Within the range of assumed density contrasts, all inversion models show the presence of the deep-rooted low-density bodies, providing a significant confidence level to the inversion results. Our favoured 3D model of the anomalous bodies is obtained from a negative density contrast of 150 kg m-3 that corresponds to bodies appear to connect the Altiplano-Puna Magma Body (AMPB) at ~20 km depth, to shallower (~5 km) pre-eruption levels beneath the Altiplano-Puna Volcanic Complex (APVC). One of the bodies is located beneath a large on-going ground uplift centred at Uturuncu volcano and the modelled ground deformation source lies within the gravimetrically imaged body of partial melt.

  8. Comparing modifiability of React Native and two native codebases

    OpenAIRE

    Abrahamsson, Robin; Berntsen, David

    2017-01-01

    Creating native mobile application on multiple platforms generate a lot of duplicate code. This thesis has evaluated if the code quality attribute modifiability improves when migrating to React Native. One Android and one iOS codebase existed for an application and a third codebase was developed with React Native. The measurements of the codebases were based on the SQMMA-model. The metrics for the model were collected with static analyzers created specifically for this project. The results cr...

  9. Quaternary extensional growth folding beneath Reno, Nevada, imaged by urban seismic profiling

    Science.gov (United States)

    Stephenson, William J.; Frary, Roxy N.; Louie, John; Odum, Jackson K.

    2013-01-01

    We characterize shallow subsurface faulting and basin structure along a transect through heavily urbanized Reno, Nevada, with high‐resolution seismic reflection imaging. The 6.8 km of P‐wave data image the subsurface to approximately 800 m depth and delineate two subbasins and basin uplift that are consistent with structure previously inferred from gravity modeling in this region of the northern Walker Lane. We interpret two primary faults that bound the uplift and deform Quaternary deposits. The dip of Quaternary and Tertiary strata in the western subbasin increases with greater depth to the east, suggesting recurrent fault motion across the westernmost of these faults. Deformation in the Quaternary section of the western subbasin is likely evidence of extensional growth folding at the edge of the Truckee River through Reno. This deformation is north of, and on trend with, previously mapped Quaternary fault strands of the Mt. Rose fault zone. In addition to corroborating the existence of previously inferred intrabasin structure, these data provide evidence for an active extensional Quaternary fault at a previously unknown location within the Truckee Meadows basin that furthers our understanding of both the seismotectonic framework and earthquake hazards in this urbanized region.

  10. Aquatic macroinvertebrate responses to native and non-native predators

    Directory of Open Access Journals (Sweden)

    Haddaway N. R.

    2014-01-01

    Full Text Available Non-native species can profoundly affect native ecosystems through trophic interactions with native species. Native prey may respond differently to non-native versus native predators since they lack prior experience. Here we investigate antipredator responses of two common freshwater macroinvertebrates, Gammarus pulex and Potamopyrgus jenkinsi, to olfactory cues from three predators; sympatric native fish (Gasterosteus aculeatus, sympatric native crayfish (Austropotamobius pallipes, and novel invasive crayfish (Pacifastacus leniusculus. G. pulex responded differently to fish and crayfish; showing enhanced locomotion in response to fish, but a preference for the dark over the light in response to the crayfish. P.jenkinsi showed increased vertical migration in response to all three predator cues relative to controls. These different responses to fish and crayfish are hypothesised to reflect the predators’ differing predation types; benthic for crayfish and pelagic for fish. However, we found no difference in response to native versus invasive crayfish, indicating that prey naiveté is unlikely to drive the impacts of invasive crayfish. The Predator Recognition Continuum Hypothesis proposes that benefits of generalisable predator recognition outweigh costs when predators are diverse. Generalised responses of prey as observed here will be adaptive in the presence of an invader, and may reduce novel predators’ potential impacts.

  11. Receiver Function Imaging of Crust and Uppermost Mantle Structure beneath the Japan Islands -Inclusion of Hi-net Data-

    Science.gov (United States)

    Yamauchi, M.; Hirahara, K.; Shibutani, T.

    2001-12-01

    We are examining a large number of teleseismic waveforms observed at stations closely distributed over the Japan Islands to construct body-wave waveform tomography data for determining 3-D crust and upper mantle structure including velocity discontinuities. As one of preparatory studies toward this final goal, we are executing array analyses of Receiver Functions (RF). RF analyses of J-array data ( 32 broad band stations and 269 short period stations ) and Freesia data ( 15 broad band stations ), whose stations are closely distributed, have provided us with new information on the structure including velocity discontinuities beneath the Japan Islands (Tada et al, 2001). In their study, for crustal imaging, RFs transformed from time to depth domain after SVD filtering ( Chevrot and Giardin, 2000 ) are projected onto 2-D profiles, which show average values for cells within +/- 50km from each cross section. However, this cell size does not satisfy our demand to draw the detailed image beneath the Japan Islands. In addition, J-array short period RFs available for the analyses are limited because of high frequency noises. In this research, Hi-net data (short period), whose stations are far more closely distributed, are newly included into our data. We make RF image with α =3 of short period J-array data and Hi-net data for events observed during a period from September, 2000 to July, 2001 with the magnitudes larger than 5.5. The total number of the stations with their average spacing of 10km is about 800 (J-array; 270, Hi-net; 500), which enables to reduce the cell size to +/- 20km at most. We show a new 3-D RF image of the crust and the uppermost mantle, whose best spatial resolution is reaching less than 5km. Therefore we can obtain much more detailed 3-D RF image beneath the whole Japan Islands.

  12. Cyclic biogeochemical processes and nitrogen fate beneath a subtropical stormwater infiltration basin

    Science.gov (United States)

    O'Reilly, Andrew M.; Chang, Ni-Bin; Wanielista, Martin P.

    2012-05-01

    A stormwater infiltration basin in north-central Florida, USA, was monitored from 2007 through 2008 to identify subsurface biogeochemical processes, with emphasis on N cycling, under the highly variable hydrologic conditions common in humid, subtropical climates. Cyclic variations in biogeochemical processes generally coincided with wet and dry hydrologic conditions. Oxidizing conditions in the subsurface persisted for about one month or less at the beginning of wet periods with dissolved O2 and NO3- showing similar temporal patterns. Reducing conditions in the subsurface evolved during prolonged flooding of the basin. At about the same time O2 and NO3- reduction concluded, Mn, Fe and SO42 - reduction began, with the onset of methanogenesis one month later. Reducing conditions persisted up to six months, continuing into subsequent dry periods until the next major oxidizing infiltration event. Evidence of denitrification in shallow groundwater at the site is supported by median NO3--N less than 0.016 mg L- 1, excess N2 up to 3 mg L- 1 progressively enriched in δ15N during prolonged basin flooding, and isotopically heavy δ15N and δ18O of NO3- (up to 25‰ and 15‰, respectively). Isotopic enrichment of newly infiltrated stormwater suggests denitrification was partially completed within two days. Soil and water chemistry data suggest that a biogeochemically active zone exists in the upper 1.4 m of soil, where organic carbon was the likely electron donor supplied by organic matter in soil solids or dissolved in infiltrating stormwater. The cyclic nature of reducing conditions effectively controlled the N cycle, switching N fate beneath the basin from NO3- leaching to reduction in the shallow saturated zone. Results can inform design of functionalized soil amendments that could replace the native soil in a stormwater infiltration basin and mitigate potential NO3- leaching to groundwater by replicating the biogeochemical conditions under the observed basin.

  13. Health care-associated native valve endocarditis: importance of non-nosocomial acquisition

    NARCIS (Netherlands)

    Benito, Natividad; Miró, José M.; de Lazzari, Elisa; Cabell, Christopher H.; del Río, Ana; Altclas, Javier; Commerford, Patrick; Delahaye, Francois; Dragulescu, Stefan; Giamarellou, Helen; Habib, Gilbert; Kamarulzaman, Adeeba; Kumar, A. Sampath; Nacinovich, Francisco M.; Suter, Fredy; Tribouilloy, Christophe; Venugopal, Krishnan; Moreno, Asuncion; Fowler, Vance G.; Gordon, David; Devi, Uma; Spelman, Denis; van der Meer, Jan T. M.; Kauffman, Carol; Bradley, Suzanne; Armstrong, William; Giannitsioti, Efthymia; Lerakis, Stamatios; Mestres, Carlos A.; Pare, Carlos; de la Maria, Cristina Garcia; Marco, Francesc; Gatell, Jose M.; Almela, Manuel; Azqueta, Manuel; Jiménez-Expósito, Maria Jesús; Sitges, Marta; Claramonte, Xavier; Armero, Yolanda; Cervera, Carlos; Falces, Carlos; Heras, Magda; Miro, José M.; Fernandez-Hidalgo, Nuria; de Vera, Pablo Rodriguez; Tornos, Pilar; Falco, Vicente; Sidani, Nisreen; Kanj-Sharara, Souha; Kanafani, Zeina; Raglio, Annibale; Goglio, Antonio; Gnecchi, Fabrizio; Valsecchi, Grazia; Rizzi, Marco; Ravasio, Veronica; Hoen, Bruno; Chirouze, Catherine; Giannitsiot, Efthymia; Leroy, Joel; Plesiat, Patrick; Bernard, Yvette; Casey, Anna; Lambert, Peter; Watkin, Richard; Elliott, Tom; Baddley, John; Patel, Mukesh; Dismukes, William; Caros, Giampiero; Mathiron, Amel Brahim; Goissen, Thomas; Delahaye, Armelle; Delahaye, François; Vandenesch, François; Vizzotti, Carla; Marin, Marcelo; Trivi, Marcelo; Lombardero, Martin; Cortes, Claudia; Casabe, José Horacio; Kogan, Silvia; Clara, Liliana; Sanchez, Marisa; Commerford, Anita; Hansa, Cass; Deetlefs, Eduan; Ntsekhe, Mpiko; Wray, Dannah; Steed, Lisa L.; Church, Preston; Cantey, Robert; Morris, Arthur; Holland, David; Murdoch, David; Chambers, Stephen; Read, Kerry; Raymond, Nigel; Lang, Selwyn; Kotsanas, Despina; Korman, Tony M.; Peterson, Gail; Southern, Paul M.; Shah, Manisha; Bedimo, Roger; Reddy, Arjun; Levine, Donald; Dhar, Gaurav; Hanlon-Feeney, Alanna; Hannan, Margaret; Kelly, Sinead; Wang, Andrew; Woods, Christopher W.; Sexton, Daniel J.; Corey, Ralph; Drew, Laura; Lalani, Tahaniyat; Chu, Vivian H.; Mazaheri, Bahram; Neuerburg, Carl; Naber, Christoph; Athan, Eugene; Henry, Margaret; Harris, Owen; Alestig, Eric; Olaison, Lars; Wikstrom, Lotta; Snygg-Martin, Ulrika; Francis, Johnson; Nair, Lathi; Thomas, Vinod; Chaiworramukkun, Jaruwan; Pachirat, Orathai; Chetchotisakd, Ploenchan; Suwanich, Tewan; Tamin, Syahidah Syed; Premru, Manica Mueller; Logar, Mateja; Lejko-Zupanc, Tatjana; Orezzi, Christina; Klein, John; Bouza, Emilio; Moreno, Mar; Rodríguez-Créixems, Marta; Marín, Mercedes; Fernández, Miguel; Muñoz, Patricia; Fernández, Rocío; Ramallo, Victor; Raoult, Didier; Thuny, Franck; Casalta, Jean-Paul; Fournier, Pierre-Edouard; Chipigina, Natalia; Kirill, Ozerecky; Vinogradova, Tatiana; Kulichenko, Vadim P.; Butkevich, O. M.; Lion, Christine; Selton-Suty, Christine; Alla, François; Coyard, Hélène; Doco-Lecompte, Thanh; Durante-Mangoni, Emanuele; Ragone, Enrico; Dialetto, Giovanni; Tripodi, Marie Françoise; Utili, Riccardo; Casillo, Roberta; Sharma, Gautam; Dickerman, Stuart A.; Street, Alan; Eisen, Damon Peter; McBryde, Emma Sue; Grigg, Leeanne; Abrutyn, Elias; Michelet, Christian; Tattevin, Pierre; Donnio, Pierre Yves; Fortes, Claudio Querido; Edathodu, Jameela; Al-Hegelan, Mashael; Font, Bernat; Anguera, Ignasi; Guma, Joan Raimon; Cereceda, M.; Oyonarte, Miguel J.; Mella, Rodrigo Montagna; Garcia, Patricia; Jones, Sandra Braun; de Oliveira Ramos, Auristela Isabel; Paiva, Marcelo Goulart; de Medeiros Tranchesi, Regina Aparecida; Woon, Lok Ley; Lum, Luh-Nah; Tan, Ru-San; Rees, David; Kornecny, Pam; Lawrence, Richard; Dever, Robyn; Post, Jeffrey; Jones, Phillip; Ryan, Suzanne; Harkness, John; Feneley, Michael; Rubinstein, Ethan; Strahilewitz, Jacob; Ionac, Adina; Mornos, Cristian; Forno, Davide; Cecchi, Enrico; de Rosa, Francesco; Imazio, Massimo; Trinchero, Rita; Wiesbauer, Franz; Gattringer, Rainer; Deans, Greg; Andrasevic, Arjana Tambic; Barsic, Bruno; Klinar, Igor; Vincelj, Josip; Bukovski, Suzana; Krajinovic, Vladimir; Corey, G. Ralph; Stafford, Judy; Baloch, Khaula; Redick, Thomas; Harding, Tina; Karchmer, A. W.; Bayer, Arnie; Durack, David T.; Moreillon, Phillipe; Eykyn, Susannah

    2009-01-01

    BACKGROUND: The clinical profile and outcome of nosocomial and non-nosocomial health care-associated native valve endocarditis are not well defined. OBJECTIVE: To compare the characteristics and outcomes of community-associated and nosocomial and non-nosocomial health care-associated native valve

  14. Upper mantle thermal variations beneath the Transantarctic Mountains inferred from teleseismic S-wave attenuation

    Science.gov (United States)

    Lawrence, Jesse F.; Wiens, Douglas A.; Nyblade, Andrew A.; Anandakrishan, Sridhar; Shore, Patrick J.; Voigt, Donald

    2006-02-01

    This study examines teleseismic S-wave attenuation variations between the Ross Sea in West Antarctica and Vostok Subglacial Highlands in East Antarctica. These analyses indicate that δt* is ~1 second greater beneath the Ross Sea than East Antarctica, with the transition occurring beneath the Transantarctic Mountains. While the structure is non-unique, low attenuation beneath East Antarctica is consistent with thick subcontinental lithosphere (>=250 km) and negligible asthenosphere. In contrast, the Ross Sea possesses a thin lithosphere underlain by thick, highly anelastic asthenosphere. Independent temperature estimates from velocity and quality factor indicate that the mantle is 200-400°C colder beneath East Antarctica than the Ross Sea between 80 and 220 km depth. The temperature variation beneath the Transantarctic Mountains may have assisted in the asymmetric uplift of the mountains. Attenuation and velocity anomalies within East Antarctica may delineate regions of elevated temperature, representing recently modified sections between older lithospheric blocks.

  15. Incipient mantle plume evolution: Constraints from ancient landscapes buried beneath the North Sea

    Science.gov (United States)

    Stucky de Quay, G.; Roberts, G. G.; Watson, J. S.; Jackson, C. A.-L.

    2017-03-01

    Geological observations that constrain the history of mantle convection are sparse despite its importance in determining vertical and horizontal plate motions, plate rheology, and magmatism. We use a suite of geological and geophysical observations from the northern North Sea to constrain evolution of the incipient Paleocene-Eocene Icelandic plume. Well data and a three-dimensional seismic survey are used to reconstruct a 58-55 Ma landscape now buried ˜1.5 km beneath the seabed in the Bressay region. Geochemical analyses of cuttings from wells that intersect the landscape indicate the presence of angiosperm debris. These observations, combined with presence of coarse clastic material, interpreted beach ridges, and a large dendritic drainage network, indicate that this landscape formed subaerially. Longitudinal profiles of paleo-rivers were extracted and inverted for an uplift rate history, indicating three distinct phases of uplift and total cumulative uplift of ˜350 m. Dinoflagellate cysts in the surrounding marine stratigraphy indicate that this terrestrial landscape formed in ˜150 km/Ma.

  16. Native Speakers' Perception of Non-Native English Speech

    Science.gov (United States)

    Jaber, Maysa; Hussein, Riyad F.

    2011-01-01

    This study is aimed at investigating the rating and intelligibility of different non-native varieties of English, namely French English, Japanese English and Jordanian English by native English speakers and their attitudes towards these foreign accents. To achieve the goals of this study, the researchers used a web-based questionnaire which…

  17. Heterogeneous Structure and Seismicity beneath the Tokyo Metropolitan Area

    Science.gov (United States)

    Nakagawa, S.; Kato, A.; Sakai, S.; Nanjo, K.; Panayotopoulos, Y.; Kurashimo, E.; Obara, K.; Kasahara, K.; Aketagawa, T.; Kimura, H.; Hirata, N.

    2010-12-01

    Beneath the Tokyo metropolitan area, the Philippine Sea Plate (PSP) subducts and causes damaged mega-thrust earthquakes. Sato et al. (2005) revealed the geometry of upper surface of PSP, and Hagiwara et al. (2006) estimated the velocity structure beneath Boso peninsula. However, these results are not sufficient for the assessment of the entire picture of the seismic hazards beneath the Tokyo metropolitan area including those due to an intra-slab M7+ earthquake. So, we launched the Special Project for Earthquake Disaster Mitigation in the Tokyo Metropolitan area (Hirata et al., 2009). Proving the more detailed geometry and physical properties (e.g. velocities, densities, attenuation) and stress field within PSP is very important to attain this issue. The core item of this project is a dense seismic array called Metropolitan Seismic Observation network (MeSO-net) for making observations in the metropolitan area (Sakai and Hirata, 2009; Kasahara et al., 2009). We deployed the 249 seismic stations with a spacing of 5 km. Some parts of stations construct 5 linear arrays at interval of 2 km such as Tsukuba-Fujisawa (TF) array, etc. The TF array runs from northeast to southwest through the center of Tokyo. In this study, we applied the tomography method to image the heterogeneous structure under the Tokyo metropolitan area. We selected events from the Japan Meteorological Agency (JMA) unified earthquake list. All data of MeSO-net were edited into event data by the selected JMA unified earthquake list. We picked the P and S wave arrival times. The total number of stations and events are 421 and 1,256, respectively. Then, we applied the double-difference tomography method (Zhang and Thurber, 2003) to this dataset and estimated the fine-scale velocity structure. The grid nodes locate 10 km interval in parallel with the array, 20 km interval in perpendicular to the array; and on depth direction, 5 km interval to a depth of less than 50 km and 10 km interval at a depth of more

  18. Electrical resistivity dynamics beneath a fractured sedimentary bedrock riverbed in response to temperature and groundwater–surface water exchange

    Directory of Open Access Journals (Sweden)

    C. M. Steelman

    2017-06-01

    Full Text Available Bedrock rivers occur where surface water flows along an exposed rock surface. Fractured sedimentary bedrock can exhibit variable groundwater residence times, anisotropic flow paths, and heterogeneity, along with diffusive exchange between fractures and rock matrix. These properties of the rock will affect thermal transients in the riverbed and groundwater–surface water exchange. In this study, surface electrical methods were used as a non-invasive technique to assess the scale and temporal variability of riverbed temperature and groundwater–surface water interaction beneath a sedimentary bedrock riverbed. Conditions were monitored at a semi-daily to semi-weekly interval over a full annual period that included a seasonal freeze–thaw cycle. Surface electromagnetic induction (EMI and electrical resistivity tomography (ERT methods captured conditions beneath the riverbed along a pool–riffle sequence of the Eramosa River in Canada. Geophysical datasets were accompanied by continuous measurements of aqueous specific conductance, temperature, and river stage. Time-lapse vertical temperature trolling within a lined borehole adjacent to the river revealed active groundwater flow zones along fracture networks within the upper 10 m of rock. EMI measurements collected during cooler high-flow and warmer low-flow periods identified a spatiotemporal riverbed response that was largely dependent upon riverbed morphology and seasonal groundwater temperature. Time-lapse ERT profiles across the pool and riffle sequence identified seasonal transients within the upper 2 and 3 m of rock, respectively, with spatial variations controlled by riverbed morphology (pool versus riffle and dominant surficial rock properties (competent versus weathered rock rubble surface. While the pool and riffle both exhibited a dynamic resistivity through seasonal cooling and warming cycles, conditions beneath the pool were more variable, largely due to the formation of river

  19. Imaging and Analyzing the Upper Lithosphere Beneath the Southern Appalachians using Global Seismic Phases Recorded by the SESAME Broadband Array

    Science.gov (United States)

    Alberts, E.; Verellen, D.; Parker, H., Jr.; Hawman, R. B.; Fischer, K. M.; Wagner, L. S.

    2016-12-01

    Global-phase seismic interferometry (GloPSI) is a seismic method that allows for the extraction of zero-offset reflections. We use the global seismic phase PKIKP as a virtual source to generate reflection profiles along three survey lines of the Southeastern Suture of the Appalachian Margin Experiment (SESAME). The broadband recordings provide constraints on long-wavelength structure that complement the higher-frequency images obtained along Consortium for Continental Reflection Profiling (COCORP) lines. Targets include structures associated with Paleozoic collision and Mesozoic extension. We focus in particular on the nature of the Southern Appalachian detachment, the Alleghanian suture and its possible relation to a zone of prominent south-dipping reflections observed on COCORP profiles, and estimating the volume of mafic intrusions added to the basement beneath the Coastal Plain. The broadband profiles also provide additional constraints on the thickness and lateral extent of Triassic sediments. Relative reflection amplitudes are used to estimate impedance contrasts to constrain the nature of major discontinuities. Over the Coastal Plain, we experiment with a number of approaches for suppressing multiple reflections generated by very low-velocity, unconsolidated sediments and poorly consolidated sedimentary rocks. The resulting improvement in image quality should allow us to better evaluate the continuity of the detachment and other orogen-wide structures.

  20. Atmospheric Waves and Dynamics Beneath Jupiters Clouds from Radio Wavelength Observations

    Science.gov (United States)

    Cosentino, Richard G.; Butler, Bryan; Sault, Bob; Morales-Juberias, Raul; Simon, Amy; De Pater, Imke

    2017-01-01

    We observed Jupiter at wavelengths near 2 cm with the Karl G. Jansky Very Large Array (VLA) in February 2015. These frequencies are mostly sensitive to variations in ammonia abundance and probe between approx. 0.5- 2.0 bars of pressure in Jupiters atmosphere; within and below the visible cloud deck which has its base near 0.7 bars. The resultant observed data were projected into a cylindrical map of the planet with spatial resolution of approx. 1500 km at the equator. We have examined the data for atmospheric waves and observed a prominent bright belt of radio hotspot features near 10 N, likely connected to the same equatorial wave associated with the 5-m hotspots. We conducted a passive tracer power spectral wave analysis for the entire map and latitude regions corresponding to eastward and westward jets and compare our results to previous studies. The power spectra analysis revealed that the atmosphere sampled in our observation (excluding the NEB region) is in a 2-D turbulent regime and its dynamics are predominately governed by the shallow water equations. The Great Red Spot (GRS) is also very prominent and has a noticeable meridional asymmetry and we compare it, and nearby storms, with optical images. We find that the meridional radio profile has a global north-south hemisphere distinction and find correlations of it to optical intensity banding and to shear zones of the zonal wind profile over select regions of latitude. Amateur optical images taken before and after our observation complemented the radio wave- length map to investigate dynamics of the equatorial region in Jupiters atmosphere. We find that two radio hotspots at 2 cm are well correlated with optical plumes in the NEB, additionally revealing they are not the same 5 m hotspot features correlated with optical dark patches between adjacent plumes. This analysis exploits the VLAs upgraded sensitivity and explores the opportunities now possible when studying gas giants, especially atmospheric

  1. Coyote's Eyes: Native Cognition Styles.

    Science.gov (United States)

    Tafoya, Terry

    The document compares and contrasts the Standard Average European (SAE) and the Standard Native American (SNA) viewpoints with regard to fostering cognitive development in children. One basic difference is demonstrated by relating a story and noting that, in terms of Native American cognitive development, no further teaching would be done. In…

  2. Listening Natively across Perceptual Domains?

    Science.gov (United States)

    Langus, Alan; Seyed-Allaei, Shima; Uysal, Ertugrul; Pirmoradian, Sahar; Marino, Caterina; Asaadi, Sina; Eren, Ömer; Toro, Juan M.; Peña, Marcela; Bion, Ricardo A. H.; Nespor, Marina

    2016-01-01

    Our native tongue influences the way we perceive other languages. But does it also determine the way we perceive nonlinguistic sounds? The authors investigated how speakers of Italian, Turkish, and Persian group sequences of syllables, tones, or visual shapes alternating in either frequency or duration. We found strong native listening effects…

  3. Native American youth and justice

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Laurence A. French

    2012-12-01

    Full Text Available Youth and delinquency issues have long been problematic among Native Americans groups both on- and off-reservation. This phenomenon is further complicated by the cultural diversity among American Indians and Alaska Natives scattered across the United States. In address these issues, the paper begins with a historical overview of Native American youth. This history presents the long tradition of federal policies that, how well intended, have resulted in discriminatory practices with the most damages attacks being those directed toward the destruction of viable cultural attributes – the same attributes that make Native Americans unique within United States society. Following the historical material, the authors contrast the pervasive Native American aboriginal ethos of harmony with that of Protestant Ethic that dominates the ethos of the larger United States society. In addition to providing general information on Native American crime and delinquency, the paper also provides a case study of Native American justice within the Navajo Nation, the largest tribe, in both size and population, in the United States. The paper concludes with a discussion of issues specific to Native American youth and efforts to address these problems.

  4. Mantle transition zone structure beneath the Canadian Shield

    Science.gov (United States)

    Thompson, D. A.; Helffrich, G. R.; Bastow, I. D.; Kendall, J. M.; Wookey, J.; Eaton, D. W.; Snyder, D. B.

    2010-12-01

    The Canadian Shield is underlain by one of the deepest and most laterally extensive continental roots on the planet. Seismological constraints on the mantle structure beneath the region are presently lacking due to the paucity of stations in this remote area. Presented here is a receiver function study on transition zone structure using data from recently deployed seismic networks from the Hudson Bay region. High resolution images based on high signal-to-noise ratio data show clear arrivals from the 410 km and 660 km discontinuities, revealing remarkably little variation in transition zone structure. Transition zone thickness is close to the global average (averaging 245 km across the study area), and any deviations in Pds arrival time from reference Earth models can be readily explained by upper-mantle velocity structure. The 520 km discontinuity is not a ubiquitous feature, and is only weakly observed in localised areas. These results imply that the Laurentian root is likely confined to the upper-mantle and if any mantle downwelling exists, possibly explaining the existence of Hudson Bay, it is also confined to the upper 400 km. Any thermal perturbations at transition zone depths associated with the existence of the root, whether they be cold downwellings or elevated temperatures due to the insulating effect of the root, are thus either non-existent or below the resolution of the study.

  5. Crawling beneath the free surface: Water snail locomotion

    Science.gov (United States)

    Lee, Sungyon; Bush, John W. M.; Hosoi, A. E.; Lauga, Eric

    2008-08-01

    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being generated by the undulation of the snail foot that is separated from the free surface by a thin layer of mucus. Here, a lubrication model is used to describe the mucus flow in the limit of small-amplitude interfacial deformations. By assuming the shape of the snail foot to be a traveling sine wave and the mucus to be Newtonian, an evolution equation for the interface shape is obtained and the resulting propulsive force on the snail is calculated. This propulsive force is found to be nonzero for moderate values of the capillary number but vanishes in the limits of high and low capillary number. Physically, this force arises because the snail's foot deforms the free surface, thereby generating curvature pressures and lubrication flows inside the mucus layer that couple to the topography of the foot.

  6. Peeking Beneath the Caldera: Communicating Subsurface Knowledge of Newberry Volcano

    Science.gov (United States)

    Mark-Moser, M.; Rose, K.; Schultz, J.; Cameron, E.

    2016-12-01

    "Imaging the Subsurface: Enhanced Geothermal Systems and Exploring Beneath Newberry Volcano" is an interactive website that presents a three-dimensional subsurface model of Newberry Volcano developed at National Energy Technology Laboratory (NETL). Created using the Story Maps application by ArcGIS Online, this format's dynamic capabilities provide the user the opportunity for multimedia engagement with the datasets and information used to build the subsurface model. This website allows for an interactive experience that the user dictates, including interactive maps, instructive videos and video capture of the subsurface model, and linked information throughout the text. This Story Map offers a general background on the technology of enhanced geothermal systems and the geologic and development history of Newberry Volcano before presenting NETL's modeling efforts that support the installation of enhanced geothermal systems. The model is driven by multiple geologic and geophysical datasets to compare and contrast results which allow for the targeting of potential EGS sites and the reduction of subsurface uncertainty. This Story Map aims to communicate to a broad audience, and provides a platform to effectively introduce the model to researchers and stakeholders.

  7. Vulnerability of freshwater native biodiversity to non-native ...

    Science.gov (United States)

    Background/Question/Methods Non-native species pose one of the greatest threats to native biodiversity. The literature provides plentiful empirical and anecdotal evidence of this phenomenon; however, such evidence is limited to local or regional scales. Employing geospatial analyses, we investigate the potential threat of non-native species to threatened and endangered aquatic animal taxa inhabiting unprotected areas across the continental US. We compiled distribution information from existing publicly available databases at the watershed scale (12-digit hydrologic unit code). We mapped non-native aquatic plant and animal species richness, and an index of cumulative invasion pressure, which weights non-native richness by the time since invasion of each species. These distributions were compared to the distributions of native aquatic taxa (fish, amphibians, mollusks, and decapods) from the International Union for the Conservation of Nature (IUCN) database. We mapped the proportion of species listed by IUCN as threatened and endangered, and a species rarity index per watershed. An overlay analysis identified watersheds experiencing high pressure from non-native species and also containing high proportions of threatened and endangered species or exhibiting high species rarity. Conservation priorities were identified by generating priority indices from these overlays and mapping them relative to the distribution of protected areas across the US. Results/Conclusion

  8. Neotectonic fault detection and lithosphere structure beneath SW of High Atlas (Morocco)

    Science.gov (United States)

    Timoulali, Youssef; Radi, Said; Azguet, Roumaissae; Bachaoui, Mostapha

    2016-08-01

    subduction zone marking the limit between SW of High Atlas and the western Meseta. A second high velocity body, dipping north beneath the Hercynian Tichka Massif is detected. This positive velocity anomaly can be interpreted as an old subduction zone marking the limit between Meseta Domain and West African Craton. The occurrence of tholeiitic and alkaline magmatism respectively in the Essaouira basin zone and in the Hercynian Ticka Massif zone leads us to conclude that remains of subduction exist in these zones. The negative lithospheric anomalies are interpreted as heat or hot asthenospheric material upwelling from depth crossing the main crustal structures in SW High Atlas. The negative lithospheric anomalies are interpreted as hot asthenospheric material or heat coming from depth to replace the detached crust. Based on our analysis of local P wave velocities and profiles, the crustal thickness beneath SW of High Atlas region varies from 30 km to 45 km in central and western part.

  9. Syntactic constraints and individual differences in native and non-native processing of wh-movement

    Directory of Open Access Journals (Sweden)

    Adrienne eJohnson

    2016-04-01

    Full Text Available There is a debate as to whether second language (L2 learners show qualitatively similar processing profiles as native speakers or whether L2 learners are restricted in their ability to use syntactic information during online processing. In the realm of wh-dependency resolution, research has examined whether learners, similar to native speakers, attempt to resolve wh-dependencies in grammatically licensed contexts but avoid positing gaps in illicit contexts such as islands. Also at issue is whether the avoidance of gap filling in islands is due to adherence to syntactic constraints or whether islands simply present processing bottlenecks. One approach has been to examine the relationship between processing abilities and the establishment of wh-dependencies in islands. Grammatical accounts of islands do not predict such a relationship as the parser should simply not predict gaps in illicit contexts. In contrast, a pattern of results showing that individuals with more processing resources are better able to establish wh-dependencies in islands could conceivably be compatible with certain processing accounts. In a self-paced reading experiment which examines the processing of wh- dependencies, we address both questions, examining whether native English speakers and Korean learners of English show qualitatively similar patterns and whether there is a relationship between working memory, as measured by counting span and reading span, and processing in both island and non-island contexts. The results of the self-paced reading experiment suggest that learners can use syntactic information on the same timecourse as native speakers, showing qualitative similarity between the two groups. Results of regression analyses did not reveal a significant relationship between working memory and the establishment of wh-dependencies in islands but we did observe significant relationships between working memory and the processing of licit wh-dependencies. As the

  10. Soil property control of biogeochemical processes beneath two subtropical stormwater infiltration basins

    Science.gov (United States)

    O'Reilly, Andrew M.; Wanielista, Martin P.; Chang, Ni-Bin; Harris, Willie G.; Xuan, Zhemin

    2012-01-01

    Substantially different biogeochemical processes affecting nitrogen fate and transport were observed beneath two stormwater infiltration basins in north-central Florida. Differences are related to soil textural properties that deeply link hydroclimatic conditions with soil moisture variations in a humid, subtropical climate. During 2008, shallow groundwater beneath the basin with predominantly clayey soils (median, 41% silt+clay) exhibited decreases in dissolved oxygen from 3.8 to 0.1 mg L-1 and decreases in nitrate nitrogen (NO3-–N) from 2.7 mg L-1 to -1, followed by manganese and iron reduction, sulfate reduction, and methanogenesis. In contrast, beneath the basin with predominantly sandy soils (median, 2% silt+clay), aerobic conditions persisted from 2007 through 2009 (dissolved oxygen, 5.0–7.8 mg L-1), resulting in NO3-–N of 1.3 to 3.3 mg L-1 in shallow groundwater. Enrichment of d15N and d18O of NO3- combined with water chemistry data indicates denitrification beneath the clayey basin and relatively conservative NO3- transport beneath the sandy basin. Soil-extractable NO3-–N was significantly lower and the copper-containing nitrite reductase gene density was significantly higher beneath the clayey basin. Differences in moisture retention capacity between fine- and coarse-textured soils resulted in median volumetric gas-phase contents of 0.04 beneath the clayey basin and 0.19 beneath the sandy basin, inhibiting surface/subsurface oxygen exchange beneath the clayey basin. Results can inform development of soil amendments to maintain elevated moisture content in shallow soils of stormwater infiltration basins, which can be incorporated in improved best management practices to mitigate NO3- impacts.

  11. The Native Language of Social Cognition

    National Research Council Canada - National Science Library

    Katherine D. Kinzler; Emmanuel Dupoux; Elizabeth S. Spelke

    2007-01-01

    .... Young infants prefer to look at a person who previously spoke their native language. Older infants preferentially accept toys from native-language speakers, and preschool children preferentially select native-language speakers as friends...

  12. Deep-crustal magma reservoirs beneath the Nicaraguan volcanic arc, revealed by 2-D and semi 3-D inversion of magnetotelluric data

    Science.gov (United States)

    Brasse, Heinrich; Schäfer, Anja; Díaz, Daniel; Alvarado, Guillermo E.; Muñoz, Angélica; Mütschard, Lutz

    2015-11-01

    A long-period magnetotelluric (MT) experiment was conducted in early 2009 in western Nicaragua to study the electrical resistivity and thus fluid/melt distribution at the Central American continental margin where the Cocos plate subducts beneath the Caribbean plate. Strike analysis yields a preference direction perpendicular to the profile, with moderate deviation from two-dimensionality, however. Two-dimensional modeling maps the sediments of the Nicaraguan Depression and a high-conductivity zone in the mid-crust, slightly offset from the arc. Further conductors are modeled in the backarc. However, these features are probably artifacts when a 2-D program is applied to data which show moderate 3-D characteristics. 3-D inversion clarifies the situation, and the major remaining conductive structure is now quasi directly beneath the volcanic chain and interpreted as a deep-seated magma deposit. Conductivity in the backarc is also relatively high and may either be caused by still existing partial melts beneath the Paleocene to Miocene volcanic arcs or by related metallic deposits in the aureoles of hydrothermal alteration.

  13. The Rise of native advertising

    Directory of Open Access Journals (Sweden)

    Marius MANIC

    2015-06-01

    Full Text Available Native advertising is described both as a new way for promoters to engage audiences and as a new, clever, source of revenue for publishers and media agencies. The debates around its morality and the need for a wide accepted framework are often viewed as calls for creativity. Aside from the various forms, strategies and the need for clarification, the fact that native advertising works and its revenue estimates increase annually transforms the new type of ad into a clear objective for companies, marketers and publishers. Native advertising stopped being a buzzword and started being a marketing reality.

  14. The crustal structure beneath the Netherlands from ambient seismic noise

    Science.gov (United States)

    Paulssen, Hanneke; Yudistira, Tedi; Trampert, Jeannot

    2017-04-01

    A 3-D shear velocity model of the crust beneath the Netherlands is determined from fundamental mode Rayleigh and Love wave group measurements derived from ambient seismic noise recordings. The data are obtained from a temporary array of broad-band seismometers in and around the Netherlands (the NARS-Netherlands project, 2008-2012) complemented with data from existing networks in the Netherlands, Belgium and Germany. Rayleigh and Love wave group velocity maps were constructed for the period range of 10 to 30 s. Lateral variations in the group velocity maps primarily reflect variations in sedimentary thickness across the Netherlands. The 2-psi Rayleigh wave and 4-psi Love wave fast directions of the group velocity maps are in agreement with the NW-SE direction of maximum compressive stress as well as with the NW-SE dominant direction of faulting in the Netherlands. The frequency dependence suggests that the azimuthal anisotropy is caused by lattice preferred orientation (LPO) of lower crustal minerals. A 3-D shear-velocity model is obtained by inversion of the group velocity maps using the Neighbourhood Algorithm. The results show a top layer that varies in thickness from 2 to 4 km with with a pattern that is similar to the base of the Rotliegend. A midcrustal discontinuity is found at a depth of about 13 km. The Moho appears to be relatively flat with an average depth of 33 km. Radial anisotropy is mainly positive (Vsh - Vsv > 0) for the lower crust. This can be an expression of LPO but also of horizontal layering or lamination. The top layer shows the largest variations in radial anisotropy with distinct areas of negative radial anisotropy that can be attributed to high-density near-vertical faulting in those regions.

  15. The stress field beneath Mt. Vesuvius (Southern Italy)

    Science.gov (United States)

    D'Auria, Luca; Massa, Bruno; De Matteo, Ada

    2014-05-01

    The Somma-Vesuvius is the smallest and one of the youngest volcanoes of the Neapolitan district. Its origin is linked to a Late Pleistocene-Holocene extension occurred along the entire Tyrrhenian margin of the Apennine chain. Nowadays, Mt. Vesuvius is a quiescent strato-volcano. Using different approaches and a comparison between observations and numerical models we have determined the spatial variations in the stress field beneath the volcano edifice. In order to achieve this target we have analyzed a focal mechanism dataset derived from 197 events recorded from Jan. 1999 to Jan. 2012. The main results highlight the presence of two seismogenic volumes characterized by markedly different stress patterns. The two volumes are separated by a layer where the seismic strain release shows a significant decrease. Previous studies postulated the existence, at about the same depth, of a ductile layer allowing the spreading of the Mt. Vesuvius edifice. We interpreted the difference in the stress pattern within the two volumes as the effect of a mechanical decoupling caused by the aforementioned ductile layer. The stress pattern in the top volume is dominated by a reverse faulting style, which agrees with the hypothesis of a seismicity driven by the spreading process. On the other hand, the stress field determined for the deep volume is consistent with a background regional field locally perturbed by the effects of the topography and of heterogeneities in the volcanic structure. Since the seismicity of the deep volume shows an intermittent behaviour and has shown to be linked to geochemical variations in the fumaroles of the volcano, we hypothesize that it results from the effect of fluid injection episodes, possibly of magmatic origin, perturbing the pore pressure within the hydrothermal system. The retrieved changes in the stress pattern could indicate variations in volcano dynamics potentially linked to the intrusion of magma at shallow depth.

  16. Determination of the Basin Structure Beneath European Side of Istanbul

    Science.gov (United States)

    Karabulut, Savas; Cengiz Cinku, Mulla; Thomas, Michael; Lamontagne, Maurice

    2016-04-01

    Istanbul (near North Anatolian Fault Zone:NAFZ, Turkey) is located in northern part of Sea of Marmara, an area that has been influenced by possible Marmara Earthquakes. The general geology of Istanbul divided into two stratigraphic unit such as sedimentary (from Oligocene to Quaternary Deposits) and bedrock (Paleozoic and Eocene). The bedrock units consists of sand stone, clay stone to Paleozoic age and limestone to Eocene age and sedimentary unit consist of sand, clay, mil and gravel from Oligocene to Quaternary age. Earthquake disaster mitigation studies divided into two important phases, too. Firstly, earthquake, soil and engineering structure problems identify for investigation area, later on strategic emergency plan can prepare for these problems. Soil amplification play important role the disaster mitigation and the site effect analysis and basin structure is also a key parameter for determining of site effect. Some geophysical, geological and geotechnical measurements are requeired to defined this relationship. Istanbul Megacity has been waiting possible Marmara Earthquake and their related results. In order to defined to possible damage potential related to site effect, gravity measurements carried out for determining to geological structure, basin geometry and faults in Istanbul. Gravity data were collected at 640 sites by using a Scientrex CG-5 Autogravity meter Standard corrections applied to the gravity data include those for instrumental drift, Earth tides and latitude, and the free-air and Bouguer corrections. The corrected gravity data were imported into a Geosoft database to create a grid and map of the Bouguer gravity anomaly (grid cell size of 200 m). As a previously results, we determined some lineminants, faults and basins beneath Istanbul City. Especially, orientation of faults were NW-SE direction and some basin structures determined on between Buyukcekmece and Kucukcekmece Lake.

  17. Distribution of Attenuation Factor Beneath the Japanese Islands

    Science.gov (United States)

    Fujihara, S.; Hashimoto, M.

    2001-12-01

    In this research, we tried to estimate the distribution of attenuation factor of seismic wave, which is closely related to the above-mentioned inelastic parameters. Here the velocity records of events from the Freesia network and the J-array network were used. The events were selected based on the following criteria: (a) events with JMA magnitudes from 3.8 to 5.0 and hypocentral distance from 20km to 200km, (b) events with JMA magnitudes from 5.1 to 6.8 and hypocentral distance from 200km to 10_?, (c) Depth of all events is greater than 30km with S/N ratio greater than 2. After correcting the instrument response, P-wave spectra were estimated. Following Boatwright (1991), the observed spectra were modeled by the theoretical spectra by assuming the following relation; Aij(f) = Si(f) Pij(f) Cj(f). Brune's model (1970) was assumed for the source model. Aij(f), Si(f), Pij(f), and Cj(f) are defined as observed spectrum, source spectrum, propagation effect, and site effect, respectively. Frequency dependence of attenuation factor was not assumed here. The global standard velocity model (AK135) is used for ray tracing. Ellipticity corrections and station elevation corrections are also done. The block sizes are 50km by 50km laterally and increase vertically. As the results of analysis, the attenuation structure beneath Japanese Islands up to the depth of 180km was reconstructed with relatively good resolution. The low Q distribution is clearly seen in central Hokkaido, western Hokkaido, Tohoku region, Hida region, Izu region, and southern Kyushu. The relatively sharp decrease in Q associated with asthenosphere can be seen below the depth of 70km.

  18. Melt generation, crystallization, and extraction beneath segmented oceanic transform faults

    Science.gov (United States)

    Gregg, P. M.; Behn, M. D.; Lin, J.; Grove, T. L.

    2009-11-01

    We examine mantle melting, fractional crystallization, and melt extraction beneath fast slipping, segmented oceanic transform fault systems. Three-dimensional mantle flow and thermal structures are calculated using a temperature-dependent rheology that incorporates a viscoplastic approximation for brittle deformation in the lithosphere. Thermal solutions are combined with the near-fractional, polybaric melting model of Kinzler and Grove (1992a, 1992b, 1993) to determine extents of melting, the shape of the melting regime, and major element melt composition. We investigate the mantle source region of intratransform spreading centers (ITSCs) using the melt migration approach of Sparks and Parmentier (1991) for two end-member pooling models: (1) a wide pooling region that incorporates all of the melt focused to the ITSC and (2) a narrow pooling region that assumes melt will not migrate across a transform fault or fracture zone. Assuming wide melt pooling, our model predictions can explain both the systematic crustal thickness excesses observed at intermediate and fast slipping transform faults as well as the deeper and lower extents of melting observed in the vicinity of several transform systems. Applying these techniques to the Siqueiros transform on the East Pacific Rise we find that both the viscoplastic rheology and wide melt pooling are required to explain the observed variations in gravity inferred crustal thickness. Finally, we show that mantle potential temperature Tp = 1350°C and fractional crystallization at depths of 9-15.5 km fit the majority of the major element geochemical data from the Siqueiros transform fault system.

  19. Crustal structure beneath Portugal from teleseismic Rayleigh Wave Ellipticity

    Science.gov (United States)

    Attanayake, Januka; Ferreira, Ana M. G.; Berbellini, Andrea; Morelli, Andrea

    2017-08-01

    Up until now, Portugal lacked a countrywide shear velocity model sampling short length-scale crustal structure, which limits interpretations of seismicity and tectonics, and predictions of strong ground motion. In turn, such interpretations and predictions are important to help mitigate risk of destruction from future large on- and offshore earthquakes similar to those that Portugal has experienced in the past (e.g. the Mw 8.5-8.7 tsunamigenic event in 1755). In this study, we measured teleseismic Rayleigh Wave Ellipticity (RWE) from 33 permanent and temporary seismic stations in Portugal with wave periods between 15 s and 60 s, and inverted it for 1-D models of shear wave velocity (Vs) structure beneath each station using a fully non-linear Monte Carlo method. Because RWE is strongly sensitive to the uppermost few kilometres of the crust, both RWE measurements and Vs models are spatially correlated with surface geology in Portugal. For instance, we find that sedimentary basins produced by rifting that had begun in the Mesozoic such as the Lusitanian Basin (LB) and the Lower Tagus-Sado Basin (LTSB) are characterised by higher RWE (lower Vs). Interestingly, we observe similar RWE (and Vs) values in the interior of the Central Iberian Zone (CIZ), which is a metamorphic belt of Paleozoic age. Together with reduced crustal thickness previously estimated for the same parts of the CIZ, this suggests that the CIZ might have experienced an episode of extension possibly simultaneous to Mesozoic rifting. The Galicia-Tras-os-Montes-Zone (GTMZ) that has undergone polyphased deformation since the Paleozoic is characterised by the lowest RWE (highest Vs) in Portugal. Ossa Morena Zone and the South Portuguese Zone exhibit intermediate Vs values when compared to that of basins and the GTMZ. Our crustal Vs model can be used to provide new insights into the tectonics, seismicity and strong ground motion in Portugal.

  20. Geophysical study of the crust and upper mantle beneath the central Rio Grande rift and adjacent Great Plains and Colorado Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Ander, M.E.

    1981-03-01

    As part of the national hot dry rock (HDR) geothermal program conducted by Los Alamos Scientific Laboratory, a regional deep magnetotelluric (MT) survey of Arizona and New Mexico was performed. The main objective of the MT project was to produce a regional geoelectric contour map of the pervasive deep electrical conductor within the crust and/or upper mantle beneath the Colorado Plateau, Basin and Range Province, and Rio Grande rift. Three MT profiles cross the Jemez lineament. Preliminary one-dimensional analysis of the data suggest the lineament is associated with anomalously high electrical conductivity very shallow in the crust. An MT/audiomagnetotelluric (AMT) study of a 161 km/sup 2/ HDR prospect was performed on the Zuni Indian Reservation, New Mexico. Two-dimensional gravity modeling of a 700-km gravity profile at 34/sup 0/30'N latitude was used to study the crust and upper mantle beneath the Rio Grande rift. Several models of each of three consecutive layers were produced using all available geologic and geophysical constraints. Two short-wavelength anomalies along the gravity profile were analyzed using linear optimization techniques.

  1. Mantle Shear-Wave Velocity Structure beneath the Hawaiian Hot Spot

    National Research Council Canada - National Science Library

    Cecily J. Wolfe; Sean C. Solomon; Gabi Laske; John A. Collins; Robert S. Detrick; John A. Orcutt; David Bercovici; Erik H. Hauri

    2009-01-01

    .... Three-dimensional images of shear-wave velocity beneath the Hawaiian Islands, obtained from a network of sea-floor and land seismometers, show an upper-mantle low-velocity anomaly that is elongated...

  2. Native Terrestrial Animal Species Richness

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all native mammals, birds, reptiles, amphibians and butterflies in the Middle-Atlantic region. The data are...

  3. Charting Transnational Native American Studies

    Directory of Open Access Journals (Sweden)

    Hsinya Huang

    2012-06-01

    Full Text Available Introduction to the Special Forum entitled "Charting Transnational Native American Studies: Aesthetics, Politics, Identity," edited by Hsinya Huang, Philip J. Deloria, Laura M. Furlan, and John Gamber

  4. Imaging Canary Island hotspot material beneath the lithosphere of Morocco and southern Spain

    Science.gov (United States)

    Miller, Meghan S.; O'Driscoll, Leland J.; Butcher, Amber J.; Thomas, Christine

    2015-12-01

    The westernmost Mediterranean has developed into its present day tectonic configuration as a result of complex interactions between late stage subduction of the Neo-Tethys Ocean, continental collision of Africa and Eurasia, and the Canary Island mantle plume. This study utilizes S receiver functions (SRFs) from over 360 broadband seismic stations to seismically image the lithosphere and uppermost mantle from southern Spain through Morocco and the Canary Islands. The lithospheric thickness ranges from ∼65 km beneath the Atlas Mountains and the active volcanic islands to over ∼210 km beneath the cratonic lithosphere in southern Morocco. The common conversion point (CCP) volume of the SRFs indicates that thinned lithosphere extends from beneath the Canary Islands offshore southwestern Morocco, to beneath the continental lithosphere of the Atlas Mountains, and then thickens abruptly at the West African craton. Beneath thin lithosphere between the Canary hot spot and southern Spain, including below the Atlas Mountains and the Alboran Sea, there are distinct pockets of low velocity material, as inferred from high amplitude positive, sub-lithospheric conversions in the SRFs. These regions of low seismic velocity at the base of the lithosphere extend beneath the areas of Pliocene-Quaternary magmatism, which has been linked to a Canary hotspot source via geochemical signatures. However, we find that this volume of low velocity material is discontinuous along strike and occurs only in areas of recent volcanism and where asthenospheric mantle flow is identified with shear wave splitting analyses. We propose that the low velocity structure beneath the lithosphere is material flowing sub-horizontally northeastwards beneath Morocco from the tilted Canary Island plume, and the small, localized volcanoes are the result of small-scale upwellings from this material.

  5. Lithospheric mantle heterogeneities beneath the Zagros Mountains and the Iranian Plateau: A petrological-geophysical study

    OpenAIRE

    Tunini, Lavinia; Jiménez-Munt, Ivone; Fernandez, Manel; Vergés, Jaume; Villaseñor, Antonio

    2015-01-01

    © The Authors 2014. Published by Oxford University Press on behalf of the Royal Astronomical Society. We apply a combined geophysical-petrological methodology in order to study the thermal, compositional, density and seismological structure of the crust and upper mantle along two transects across the Arabia-Eurasia collision region. Results on the crustal thickness show minimum values beneath the Arabia Platform and Central Iran (42-43 km), and maximum values beneath the Sanandaj Sirjan zone ...

  6. Native Geoscience: Pathways to Knowledge

    Science.gov (United States)

    Bolman, J. R.; Seielstad, G.

    2006-12-01

    We are living in a definite time of change. Distinct changes are being experienced in our most sacred and natural environments. This is especially true on Native lands. Native people have lived for millennia in distinct and unique ways. The knowledge of balancing the needs of people with the needs of our natural environments is paramount in all tribal societies. This inherent accumulated knowledge has become the foundation on which to build a "blended" contemporary understanding of western science. The Dakota's and Northern California have embraced the critical need of understanding successful tribal strategies to engage educational systems (K-12 and higher education), to bring to prominence the professional development opportunities forged through working with tribal peoples and ensure the continued growth of Native earth and environmental scientists The presentation will highlight: 1) past and present philosophies on building and maintaining Native/Tribal students in earth and environmental sciences; 2) successful educational programs/activities in PreK-Ph.D. systems; 3) current Native leadership development in earth and environmental sciences; and 4) forward thinking for creating proaction collaborations addressing sustainable environmental, educational and social infrastructures for all people. Humboldt State University (HSU) and the University of North Dakota's Northern Great Plains Center for People and the Environment and the Upper Midwest Aerospace Consortium (UMAC) have been recognized nationally for their partnerships with Native communities. Unique collaborations are emerging "bridging" Native people across geographic areas in developing educational/research experiences which integrate the distinctive earth/environmental knowledge of tribal people. The presentation will highlight currently funded projects and initiatives as well as success stories of emerging Native earth system students and scientists.

  7. A new tomographic image on the Philippine Sea Slab beneath Tokyo - Implication to seismic hazard in the Tokyo metropolitan region -

    Science.gov (United States)

    Hirata, N.; Sakai, S.; Nakagawa, S.; Ishikawa, M.; Sato, H.; Kasahara, K.; Kimura, H.; Honda, R.

    2012-12-01

    In central Japan, the Philippine Sea plate (PSP) subducts beneath the Tokyo metropolitan region. Devastating M8-class earthquakes occurred on the upper surface of the Philippine Sea plate (SPS), examples of which are the Genroku earthquake of 1703 (magnitude M=8.0) and the Kanto earthquake of 1923 (M=7.9), which had 105,000 fatalities. A M7 or greater (M7+) earthquake in this region at present has high potential to produce devastating loss of life and property with even greater global economic repercussions although it is smaller than the megathrust type M8-class earthquakes. This great earthquake is evaluated to occur with a probability of 70 % in 30 years by the Earthquake Research Committee of Japan. The M7+ earthquakes may occur either on the upper surface or intra slab of PSP. The Central Disaster Management Council of Japan estimates the next great M7+ earthquake will cause 11,000 fatalities and 112 trillion yen (1 trillion US$) economic loss at worst case if it occur beneath northern Tokyo bay with M7.3. However, the estimate is based on a source fault model by conventional studies about the PSP geometry. To evaluate seismic hazard due to the great quake we need to clarify the geometry of PSP and also the Pacific palate (PAP) that subducs beneath PSP. We identify those plates with use of seismic tomography and available deep seismic reflection profiling and borehole data in southern Kanto area. We deployed about 300 seismic stations in the greater Tokyo urban region under the Special Project for Earthquake Disaster Mitigation in Tokyo Metropolitan Area. We obtain clear P- and S- wave velocity (Vp and Vs) tomograms which show a clear image of PSP and PAP. A depth to the top of PSP, 20 to 30 kilometer beneath northern part of Tokyo bay, is about 10 km shallower than previous estimates based on the distribution of seismicity (Ishida, 1992). This shallower plate geometry changes estimations of strong ground motion for seismic hazards analysis within the Tokyo

  8. Observations of turbulence beneath sea ice in southern McMurdo Sound, Antarctica

    Directory of Open Access Journals (Sweden)

    C. L. Stevens

    2009-10-01

    Full Text Available The first turbulence profiler observations beneath land fast sea ice which is directly adjacent to an Antarctic ice shelf are described. The stratification in the 325 m deep water column consisted of a layer of supercooled water in the upper 40 m lying above a quasi-linearly stratified water column with a sharp step in density at mid-depth. Turbulent energy dissipation rates were on average 3×10−8 m2 s−3 with peak bin-averaged values reaching 4×10−7 m2 s−3. The local dissipation rate per unit area was estimated to be 10 m Wm−2 on average with a peak of 50 m Wm−2. These values are consistent with a moderate baroclinic response to the tides. The small-scale turbulent energetics lie on the boundary between isotropy and buoyancy-affected. This will likely influence the formation and aggregation of frazil ice crystals within the supercooled layer. The data suggest that the large crystals observed in McMurdo Sound will transition from initial growth at scales smaller than the Kolmogorov lengthscale to sizes substantially (1–2 orders of magnitude greater than the Kolmogorov scale. An estimate of the experiment-averaged vertical diffusivity of mass Kρ yields a coefficient of around 2×10−4 m2s−1 although this increased by a factor of 2 near the surface. Combining this estimate of Kρ with available observations of average and maximum currents suggests the layer of supercooled water can persist for a distance of ~250 km from the front of the McMurdo Ice Shelf.

  9. A reference model for crust and uppermost mantle beneath Antarctica

    Science.gov (United States)

    Shen, W.; Wiens, D.; Gerstoft, P.; Bromirski, P. D.; Stephen, R. A.; Aster, R. C.; Nyblade, A.; Winberry, J. P.; Huerta, A. D.; Anandakrishnan, S.; Hansen, S. E.; Wilson, T. J.; Heeszel, D.

    2016-12-01

    Since the last decade of the 20th Century, over 300 broad-band seismic stations have been deployed across the continent of Antarctica (e.g., temporary networks such as TAMSEIS, AGAP/GAMSEIS, POLENET/ANET, TAMNNET and RIS/DRIS by US geoscientists, as well as stations deployed by other countries). In this presentation, we discuss our recent effort that builds a reference crustal and uppermost mantle shear velocity (Vs) model for continental Antarctica based on those seismic arrays. The data analysis for this effort consists of four steps. First, we compute ambient noise cross-correlations between all possible station pairs and use them to construct Rayleigh wave phase and group velocity maps at a continental scale. Coherence of the new maps with maps generated from teleseismic earthquake data from an earlier study (Heeszel et al., 2016) confirms the high quality of both maps and the minor difference helps quantify the map uncertainties. Second, we compute P receiver function waveforms for each station in Antarctica. Third, we collect Rayleigh waves generated by teleseismic earthquakes and measure their horizontal to vertical (H/V) ratio at each station. Fourth and finally, by combing all seismic measurements from the first three steps together with the phase velocity maps by Heeszel et al.(2016) using a non-linear Monte Carlo (MC) inversion algorithm, we built a 3-D model for the crust and uppermost mantle beneath continental Antarctica and its periphery to a depth of 150 km. This high resolution model, together with associated uncertainty estimates from the MC inversion, serve as a starting point for further improvement and geological interpretation. A variety of tectonic features, including a slower but highly heterogeneous West Antarctica and a much faster East Antarctica, are present in the 3D model. A better image of these features from the 3D model helps further investigation of the thermal and dynamic state of Antarctica's lithosphere and underlying

  10. Nativization Processes in L1 Esperanto.

    Science.gov (United States)

    Bergen, Benjamin K.

    2001-01-01

    Describes characteristics of the Native Esperanto of eight speakers, ranging from age 6 to 14 years. Found bilingualism and nativization effects, differentiating native from non-native Esperanto speech. Among these effects are loss or modification of the accusative case, phonological reduction, attrition of tense/aspect system, and pronominal…

  11. Crust and Upper Mantle Structure beneath Isparta Angle in SW Turkey from P and S Receiver Functions

    Science.gov (United States)

    Kahraman, M.; Turkelli, N.; Özacar, A.; Sandvol, E. A.; Teoman, U.

    2015-12-01

    what appears to be imaged northern tip of slab at ~45 km depth. Finally, ~30km crustal thickness released in southeast beneath the Cyprus. On the other hand; preliminary results of S RFs cross-sections present the LAB boundary between ~60 to ~90 km depth range, observed almost beneath all profiles and clear positive phase arrivals right below the LAB depths.

  12. Profile of cry from native Bacillus thuringiensis isolates and ...

    African Journals Online (AJOL)

    The characterization of 255 Bacillus thuringiensis isolates of Coorg, Sharavatti and BR hills, containing genes known to be active against coleopteran and lepidopteran insect species was done through PCR amplification using the specific and degenerate primers. The isolates were also tested for their insecticidal activity ...

  13. Profile of cry from native Bacillus thuringiensis isolates and ...

    African Journals Online (AJOL)

    oyaide

    2013-05-29

    May 29, 2013 ... There were six mismatches between the two amino acid sequences. The cry1I- type ... strategies to ensure sustainability of the environment. (Ozturk et al. .... Gene specific primer which was synthesized at Sigma Aldrich Pvt.

  14. Profile of cry from native Bacillus thuringiensis isolates and ...

    African Journals Online (AJOL)

    oyaide

    2013-05-29

    . INTRODUCTION. Chemical insecticides .... One of the gene namely, cry1I was selected for further cloning and analysis of expression. ...... ther studies are in progress to ascertain the nature of the protein and its novelty and ...

  15. Atmospheric waves and dynamics beneath Jupiter's clouds from radio wavelength observations

    Science.gov (United States)

    Cosentino, Richard G.; Butler, Bryan; Sault, Bob; Morales-Juberías, Raúl; Simon, Amy; de Pater, Imke

    2017-08-01

    We observed Jupiter at wavelengths near 2 cm with the Karl G. Jansky Very Large Array (VLA) in February 2015. These frequencies are mostly sensitive to variations in ammonia abundance and probe between ∼ 0.5 - 2.0 bars of pressure in Jupiter's atmosphere; within and below the visible cloud deck which has its base near 0.7 bars. The resultant observed data were projected into a cylindrical map of the planet with spatial resolution of ∼1500 km at the equator. We have examined the data for atmospheric waves and observed a prominent bright belt of radio hotspot features near 10°N, likely connected to the same equatorial wave associated with the 5-μm hotspots. We conducted a passive tracer power spectral wave analysis for the entire map and latitude regions corresponding to eastward and westward jets and compare our results to previous studies. The power spectra analysis revealed that the atmosphere sampled in our observation (excluding the NEB region) is in a 2-D turbulent regime and its dynamics are predominately governed by the shallow water equations. The Great Red Spot (GRS) is also very prominent and has a noticeable meridional asymmetry and we compare it, and nearby storms, with optical images. We find that the meridional radio profile has a global north-south hemisphere distinction and find correlations of it to optical intensity banding and to shear zones of the zonal wind profile over select regions of latitude. Amateur optical images taken before and after our observation complemented the radio wavelength map to investigate dynamics of the equatorial region in Jupiter's atmosphere. We find that two radio hotspots at 2 cm are well correlated with optical plumes in the NEB, additionally revealing they are not the same 5 μm hotspot features correlated with optical dark patches between adjacent plumes. This analysis exploits the VLA's upgraded sensitivity and explores the opportunities now possible when studying gas giants, especially atmospheric dynamics

  16. Prominent reflector beneath around the segmentation boundary between Tonankai-Nankai earthquake area

    Science.gov (United States)

    Nakanishi, A.; Shimomura, N.; Fujie, G.; Kodaira, S.; Obana, K.; Takahashi, T.; Yamamoto, Y.; Yamashita, M.; Takahashi, N.; Kaneda, Y.; Mochizuki, K.; Kato, A.; Iidaka, T.; Kurashimo, E.; Shinohara, M.; Takeda, T.; Shiomi, K.

    2013-12-01

    In the Nankai Trough subduction seismogenic zone, the Nankai and Tonankai earthquakes had often occurred simultaneously, and caused a great event. In most cases, first break of such large events of Nankai Trough usually begins from southwest off the Kii Peninsula so far. The idea of split Philippine Sea plate between the Kii Peninsula and the Shikoku Island, which explains seismicity, tectonic background, receiver function image and historical plate motion, was previously suggested. Moreover, between the Kii Peninsula and the Shikoku Island, there is a gap of deep low-frequency events observed in the belt-like zone along the strike of the subducting Philippine Sea plate. In 2010 and 2011, we conducted the large-scale high-resolution wide-angle and reflection (MCS) seismic study, and long-term observation from off Shikoku and Kii Peninsula. Marine active source seismic data have been acquired along grid two-dimensional profiles having the total length of ~800km/year. A three-dimensional seismic tomography using active and passive seismic data observed both land and ocean bottom stations have been also performed. From those data, we found a possible prominent reflector imaged in the offshore side in the Kii channel at the depth of ~18km. The velocity just beneath the reflector cannot be determined due to the lack of ray paths. Based of the amplitude information, we interpret the reflector as the forearc Moho based on the velocity gap (from ~6.4km/s to ~7.4km/s). However, the reflector is shallower than the forearc Moho of other area along the Nankai Trough. Similar reflectors are recognized along other seismic profiles around the Kii channel. In this presentation, we will show the result of structure analysis to understand the peculiar structure including the prominent reflector around the Kii channel. Relation between the structure and the existence of the segmentation of the Nankai megathrust earthquake or seismic gap of the deep low-frequency events will be also

  17. Mapping the indentation between the Iberian and Eurasian plates beneath the Western Pyrenees/Eastern Cantabrian Mountains from receiver function analysis

    Science.gov (United States)

    Díaz, J.; Pedreira, D.; Ruiz, M.; Pulgar, J. A.; Gallart, J.

    2012-10-01

    In the last decades, active seismic profiling in the northern part of the Iberian Peninsula has evidenced that the Alpine collision between the Iberian and Eurasian plates resulted in a complex crustal structure, with the Iberian crust underthrusting the Eurasian crust and reaching depths of at least 45-50 km beneath the Pyrenean chain and the Cantabrian Mountains. In the transition between these two zones the situation is particularly complex, as evidenced in previous wide-angle and passive seismic studies. This contribution focuses in getting new clues on the crustal structure of this transitional zone through receiver function (RF) analysis of teleseismic data recorded at permanent and temporary stations located in both the Spanish and French sides of the Western Pyrenees. Different techniques (H-κ stacking, pseudo-migration, synthetic 2D modeling) have been considered in the analysis. Passive seismic data from previous temporary deployments in the zone have been reworked and added to the discussion. A first order result is that passive seismic data are broadly consistent with the indentation of the Iberian and Eurasian crusts inferred from active seismic profiling, thus providing a completely independent confirmation of this feature. For the first time, an Iberian Moho underlying the Eurasian crust is documented from RF beneath the stations located at the Northern side of the Pyrenean range. Moreover, clear indications of dipping interfaces are observed at some stations. The new RF results suggest that in the crustal indentation beneath the Basque Massifs area, the Eurasian crust extends farther south with respect to the image inferred from active seismic data. This new geometry implies that the Pamplona transfer zone has played a major role in the regional geodynamic history.

  18. Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets: Implications for overdeepening origin and evolution

    Science.gov (United States)

    Patton, H.; Swift, D. A.; Clark, C. D.; Livingstone, S. J.; Cook, S. J.

    2016-09-01

    Glacier bed overdeepenings are ubiquitous in glacier systems and likely exert significant influence on ice dynamics, subglacial hydrology, and ice stability. Understanding of overdeepening formation and evolution has been hampered by an absence of quantitative empirical studies of their distribution and morphology, with process insights having been drawn largely from theoretical or numerical studies. To address this shortcoming, we first map the distribution of potential overdeepenings beneath the Antarctic and Greenland ice sheets using a GIS-based algorithm that identifies closed-contours in the bed topography and then describe and analyse the characteristics and metrics of a subset of overdeepenings that pass further quality control criteria. Overdeepenings are found to be widespread, but are particularly associated with areas of topographically laterally constrained ice flow, notably near the ice sheet margins where outlet systems follow deeply incised troughs. Overdeepenings also occur in regions of topographically unconstrained ice flow (for example, beneath the Siple Coast ice streams and on the Greenland continental shelf). Metrics indicate that overdeepening growth is generally allometric and that topographic confinement of ice flow in general enhances overdeepening depth. However, overdeepening depth is skewed towards shallow values - typically 200-300 m - indicating that the rate of deepening slows with overdeepening age. This is reflected in a decline in adverse slope steepness with increasing overdeepening planform size. Finally, overdeepening long-profiles are found to support headward quarrying as the primary factor in overdeepening development. These observations support proposed negative feedbacks related to hydrology and sediment transport that stabilise overdeepening growth through sedimentation on the adverse slope but permit continued overdeepening planform enlargement by processes of headward erosion.

  19. Imaging of the Deep Structure and Extension of the North Anatolian Fault Zone by Magnetotelluric Method Beneath the Marmara Sea

    Science.gov (United States)

    Kaya, T.; Ogawa, Y.; Kasaya, T.; Tank, B.; Honkura, Y.; Tuncer, M. K.; Oshiman, N.; Matsushima, M.

    2011-12-01

    Relative motions of the Arabian and African plates with respect to stable Eurasian plate resulted in westward movement of the Anatolian block and produced two main fault zones in Turkey. The most active one, the North Anatolian Fault Zone (NAFZ), hosted destructive earthquakes during the history causing not only damage in the buildings but also thousands of causalities. The migration of large earthquakes along the NAFZ from east to west in 20th century, occurrence of the last earthquakes (1999 Izmit and Duzce) by the side of Marmara Sea, and owning the fault segment which has not ruptured since 1766 made the Marmara Sea a potential location for the next large rupture on the NAFZ. Seismic, geodetic and other studies showed complexity of the structure suggesting various estimates about the extension of the NAFZ through the Marmara Sea. In this study, we benefit from the high depth resolution of the Magnetotelluric (MT) method to resolve the electrical resistivity structure beneath the Marmara Sea and disclose its relation with the geologic structure. In order to investigate extension of the NAFZ beneath the Marmara Sea we deployed long period ocean bottom electromagnetic data at 16 sites which form 4 profiles perpendicular to the possible traces of the NAFZ. Variation of the geoelectric strike from east to west demonstrates different oriented faults in the Marmara Sea. The highly conductive anomaly in electrical resistivity models extends from crustal depths to the lithosphere and merges with the melted mantle material. This conductive anomaly is surrounded by relatively resistive anomalies which imply continuation of the fault structure from land to the Marmara Sea. Our results clear the location of the highly conductive and resistive anomalies that has crucial implications in two aspects; conductive anomaly may trigger the micro-seismic activity and resistive anomalies may refer to the asperity zones where stress accumulation result in large earth quakes.

  20. Crustal root beneath the Rif Cordillera as imaged from both active seismic data and teleseismic receiver functions.

    Science.gov (United States)

    Diaz, Jordi; Gil, Alba; Gallart, Josep; Carbonell, Ramon; Harnafi, Mimoun; Levander, Alan

    2015-04-01

    The Rif cordillera forms, together with the Betic ranges, one of the tightest orogenic arcs on Earth. This continental boundary zone is dominated now by the slow convergence between Nubia and Eurasia, but with clear evidences of extensional tectonics. One of the missing elements to constrain the complex geodynamics of the Gibraltar Arc System is the knowledge of the crustal architecture beneath northern Morocco. In the last decade a major effort has been done in this sense, from active and passive seismics. We compile here the recent results available from the Rif domains. Two 330 km long wide angle DSS profiles were recorded end of 2011 across the Rif in NS and EW transects within the Rifsis project, complemented by onshore recordings of the Gassis-WestMed marine profiles. At the same period, BB seismic arrays were deployed in the area within Topo-Iberia and Picasso projects, allowing receiver function analyses of crustal depths. The ray-tracing modeling of the Rifsis profiles reveal a large Moho step and an area of crustal thickening both in EW and NS directions, grossly coincident with the Bouguer gravity anomalies. The deployment logistics allowed that all the stations recorded all the shots, thus providing useful offline data. We will use here all available in-line and offline data to provide a map of the crustal thickness in northern Morocco. We combined two approaches: i) a hyperbolic time reduction applied to the seismic data, resulting in low-fold stacks in which the reflections from the Moho should appear as subhorizontal lines; ii) the arrival times of the observed PmP phases allow, assuming a mean crustal velocity, to assign a midpoint crustal thickness to each lecture. Although some uncertainties may be inherent to those approaches, a large crustal root, reaching more than 50 km, is well documented in the central part of the Rif Cordillera, close to the zone where the Alboran slab may still be attached to the lithosphere. We also compared these results

  1. Literacy Skill Differences between Adult Native English and Native Spanish Speakers

    Science.gov (United States)

    Herman, Julia; Cote, Nicole Gilbert; Reilly, Lenore; Binder, Katherine S.

    2013-01-01

    The goal of this study was to compare the literacy skills of adult native English and native Spanish ABE speakers. Participants were 169 native English speakers and 124 native Spanish speakers recruited from five prior research projects. The results showed that the native Spanish speakers were less skilled on morphology and passage comprehension…

  2. Cross-Language Perception of Cantonese Vowels Spoken by Native and Non-Native Speakers

    Science.gov (United States)

    So, Connie K.; Attina, Virginie

    2014-01-01

    This study examined the effect of native language background on listeners' perception of native and non-native vowels spoken by native (Hong Kong Cantonese) and non-native (Mandarin and Australian English) speakers. They completed discrimination and an identification task with and without visual cues in clear and noisy conditions. Results…

  3. Channelling of Melt Above Plumes and Beneath MORs

    Science.gov (United States)

    Mueller, K.; Schmeling, H.

    2003-12-01

    We investigate melt transportation in partially molten rocks under different stress fields above the head of a mantle plume or beneath a spreading mid-oceanic ridge under hydrous and anhydrous conditions. We model such aggregates with the 2D-FD code FDCON [1] by means of a porous deformable matrix with melt under the influence of a given stress field to clarify the following key questions: Could channeling occur in a matrix containing a random melt distribution under a given stress field? Which orientation does it take? Is it possible to achieve a focusing of melt towards a MOR (dykes)? Does applying simple or pure shear to the matrix result in a difference in the formation and orientation of channels? How does the channel instability evolve during finite simple shear? In a deforming partially molten aggregate, weakening of the solid matrix due to the presence of melt creates an instability in which melt is localized by the following mechanism: regions of initially high melt fraction are areas of low viscosity and pressure, so that melt is drawn into these regions from higher pressure surroundings. This further enhances the melt weakening, producing a self-excited localization mechanism [2]. The channeling developing in models with a random melt distribution of 3.5 +/- 0.5% shows that melt is accumulated preferably in inclined channels. For both, simple as well as pure shear, the growth rate is highest for an orientation parallel to the direction of the maximum compressive stress and proportional to applied stress and the reverse of the Melt Retention Number. This also confirms the theoretical growth rate found by Stevenson [2]. In our isothermal models we found that the influence of water reduces the growth rate, in contrast to non-isothermal models of Hall [3]. Under simple shear melt channels evolve from an irregular melt distribution at angles of 45 degrees to the direction of shear. Upon further straining they rotate out of the orientation of maximum growth

  4. Seismic Investigation of Sediments Beneath Antarctic Ice Streams

    Science.gov (United States)

    Luthra, Tarun

    Fault zones are areas of localized deformation that accommodate strain in the Earth's crust accumulated over time due to tectonic motion or stress transfer from adjacent areas. Faults are traditionally considered to accommodate this strain by either constant slow movement (creep), or by rapid catastrophic failure events (earthquakes). The behavior of faults which produce earthquakes has been extensively studied, including characterization of the time and slip predictability of earthquakes, frequency-magnitude distributions, aftershock decay patterns, dynamic triggering, and frictional processes. Chance observations in global positioning system (GPS) data from the Vancouver Island area in 2001 revealed a new kind of fault slip that had not been considered before, slowslip events. Since those early observations, slow-slip events have been observed at most major subduction interfaces and even in glacial systems. In this dissertation, I strive to answer some of the fundamental questions about slow-slip systems. Little is known about the dynamics of these systems and how they operate. Scattered laboratory observations have provided clues, but this study is the first systematic examination of slow-slip earthquakes and their frictional behavior in the laboratory. I examine questions such as what controls how a fault zone will fail and what the velocity and normal stress sensitives are, then connect those mechanisms to observations from a natural slow-slip system beneath Whillans Ice Stream in western Antarctica. In chapter 1, I demonstrate how to modify the stiffness of the testing machine to create slow-slip events in the laboratory inartificial granular material. I also present a method to automatically calculate the stiffness of each slip event in a given experiment. Chapter 2 extends this work into a synthetic fault gouge material and carefully examines the sensitivity of the system to the stiffness of the testing apparatus. Chapter 3 introduces the new parameter of

  5. Mohorovicic discontinuity depth analysis beneath North Patagonian Massif

    Science.gov (United States)

    Gómez Dacal, M. L.; Tocho, C.; Aragón, E.

    2013-05-01

    The North Patagonian Massif is a 100000 km2, sub-rectangular plateau that stands out 500 to 700 m higher in altitude than the surrounding topography. The creation of this plateau took place during the Oligocene through a sudden uplift without noticeable internal deformation. This quite different mechanical response between the massif and the surrounding back arc, the short time in which this process took place and a regional negative Bouguer anomaly in the massif area, raise the question about the isostatic compensation state of the previously mentioned massif. In the present work, a comparison between different results about the depth of the Mohorovicic discontinuity beneath the North Patagonian Massif and a later analysis is made. It has the objective to analyze the crustal thickness in the area to contribute in the determination of the isostatic balance and the better understanding of the Cenozoic evolution of the mentioned area. The comparison is made between four models; two of these were created with seismic information (Feng et al., 2006 and Bassin et al., 2000), another model with gravity information (Barzaghi et al., 2011) and the last one with a combination of both techniques (Tassara y Etchaurren, 2011). The latter was the result of the adaptation to the work area of a three-dimensional density model made with some additional information, mainly seismic, that constrain the surfaces. The work of restriction and adaptation of this model, the later analysis and comparison with the other three models and the combination of both seismic models to cover the lack of resolution in some areas, is presented here. According the different models, the crustal thickness of the study zone would be between 36 and 45 Km. and thicker than the surrounding areas. These results talk us about a crust thicker than normal and that could behave as a rigid and independent block. Moreover, it can be observed that there are noticeable differences between gravimetric and seismic

  6. Small length scale heterogeneity beneath the East Pacific Rise

    Science.gov (United States)

    Mallick, S.; Salters, V. J.; Perfit, M. R.

    2009-12-01

    We found two areas (~1.80°N and Siqueiros Transform Fault, STF) on the East Pacific Rise (EPR) where ridge basalts show large variation in chemical and isotope compositions compared to the other EPR basalts. Samples from ~1.80°N have relatively large ranges in trace element abundances(Ba/Zr = 0.11-0.80, Ce/Yb = 2.64-7.77) and isotope ratios 87Sr/86Sr = 0.70226-0.70282, 143Nd/144Nd = 0.513070-0.513275, 176Hf/177Hf = 0.283105-0.283281, 206Pb/204Pb = 17.54-18.62) encompassing ~70% of the variability shown by EPR ridge basalts though they are collected from 2 higher than most EPR basalts but with 87Sr/86Sr and 143Nd/144Nd similar to EPR basalts. The second group has incompatible trace elements similar to average EPR basalts but are among the most depleted in isotope ratios and similar to the Garrett FZ lavas from SEPR. The degree of isotopic variation observed along this 25km ridge segments is similar in amplitude as the variations observed in EPR seamounts. The large variation in a small area indicates there are significant small-scale heterogeneities in the sub-ridge mantle and that ridge basalts average melts from a smaller area of a mantle than the proposed length scale of melting (100km) and points at efficient melt extraction and inefficient mixing of melts. Samples from STF also show a wide range in chemical compositions (Ba/Zr = 0.03-0.79, Ce/Yb = 1.83-11.65) and isotope ratios (87Sr/86Sr= 0.70233-0.70285, 143Nd/144Nd = 0.513011-0.513189, 176Hf/177Hf = 0.283043-0.283225, 206Pb/204Pb=18.12-18.66) within the compositional range found in NEPR basalts, but lacking samples with depleted isotopic composition as observed at ~1.80°N and at the Garrett FZ. Previous studies have shown that the STF basalts are derived from the shallow mantle (<1GPa).This suggests that this shallow mantle must have been able to either retain or regain its more fertile composition during melting beneath the ridge. Basalts from west part of the STF have isotopic compositions similar to

  7. A cross-case analysis of three Native Science Field Centers

    Science.gov (United States)

    Augare, Helen J.; Davíd-Chavez, Dominique M.; Groenke, Frederick I.; Little Plume-Weatherwax, Melissa; Lone Fight, Lisa; Meier, Gene; Quiver-Gaddie, Helene; Returns From Scout, Elvin; Sachatello-Sawyer, Bonnie; St. Pierre, Nate; Valdez, Shelly; Wippert, Rachel

    2017-06-01

    Native Science Field Centers (NSFCs) were created to engage youth and adults in environmental science activities through the integration of traditional Native ways of knowing (understanding about the natural world based on centuries of observation including philosophy, worldview, cosmology, and belief systems of Indigenous peoples), Native languages, and Western science concepts. This paper focuses on the Blackfeet Native Science Field Center, the Lakota Native Science Field Center, and the Wind River Native Science Field Center. One of the long-term, overarching goals of these NSFCs was to stimulate the interest of Native American students in ways that encouraged them to pursue academic and career paths in science, technology, engineering, and mathematics (STEM) fields. A great deal can be learned from the experiences of the NSFCs in terms of effective educational strategies, as well as advantages and challenges in blending Native ways of knowing and Western scientific knowledge in an informal science education setting. Hopa Mountain—a Bozeman, Montana-based nonprofit—partnered with the Blackfeet Community College on the Blackfeet Reservation, Fremont County School District #21 on the Wind River Reservation, and Oglala Lakota College on the Pine Ridge Reservation to cooperatively establish the Native Science Field Centers. This paper presents a profile of each NSFC and highlights their program components and accomplishments.

  8. Native Youth Businesses: Native American Youth Entrepreneurship Projects.

    Science.gov (United States)

    Children Today, 1994

    1994-01-01

    Describes five demonstration projects intended to stimulate innovative community approaches to developing entrepreneurial activities for Native American youth. Each of the projects is charged with meeting the community's need to train young persons with relevant entrepreneurial orientations and management skills to improve economic development.…

  9. Native and Non-Native: What Can They Offer?

    Science.gov (United States)

    Tajino, Akira; Tajino, Yasuko

    2000-01-01

    Discusses the contribution that joint instruction by a native-speaking teacher and a nonnative-speaking teacher can make to classroom language learning. Reviews the last decade's team-teaching practice in Japanese secondary English-as-Foreign-language classrooms to explore how two teachers with different linguistic and cultural backgrounds can…

  10. Three-dimensional passive mantle flow beneath mid-ocean ridges: an analytical approach

    Science.gov (United States)

    Ligi, Marco; Cuffaro, Marco; Chierici, Francesco; Calafato, Antonino

    2008-11-01

    We discuss theoretical and computational method on plate-driven mantle flow beneath mid-ocean ridges. We consider a steady-state flow induced by motion of overlying rigid plates in an incompressible viscous mantle beneath a generic ridge-transform-ridge plate boundary. No assumption of orthogonal and symmetric spreading at ridge axis is made. Analytical solutions for viscosity flow in a half-space and in a layered viscosity mantle beneath an infinitesimal thickness lithosphere and beneath plates that thicken with increasing age, are presented. Numerical calculations were carried out using a standard fast Fourier transform algorithm. The difficulty of using standard Fourier methods to predict accurately the mantle flow field in the proximity of the plate boundaries is overcome by applying the Gegenbauer reconstruction post-processing technique to the Fourier pseudo-spectral solutions. Finally, we present some examples of flow computations. We consider, for both models, two different ridge-transform-ridge geometries consisting of 100 and 1000 km offsets of two ridge segments spreading at 15 mm/yr half rate. We found a significant difference in the flow structure between the two flow models close to ridge axis and ridge-transform intersections. The proposed model and methods are useful for fast mantle flow calculations to investigate melting processes beneath spreading centres, and to predict the relationship between mantle temperature, crustal thickness and geochemistry of the oceanic crust.

  11. Fungal communities in soil beneath Scots pine and their stumps. Effect of fungi on Heterobasidion annosum and Armillaria ostoyae growth

    Directory of Open Access Journals (Sweden)

    Hanna Kwaśna

    2014-08-01

    Full Text Available The soil beneath 30-year-old Scots pines, was inhabited by fungi communities which were at least iwicc as big as communities from ihe 49-year-old stand. The fungi communities in soil beneath the stumps were much smaller compared to those beneath the live trees and more abundant in the 30- than in the 49--year-old stand. The fungal communities in soil beneath the 30-year-old pines have bigger antagonistic effect on Heterobasidion annosum and Armillaria ostoyae than those beneath the 49-year-old stand. The decrease in density of fungi and in the frequency of species antagonistic to H. annosum and A. ostoyae resulted in the decrease of the antagonistic effect on both pathogens in soil beneath pine stumps.

  12. Native grass hydroseed development : establishment protocols for three native Hawaiian plants on roadside areas.

    Science.gov (United States)

    2012-08-01

    The biggest mistake with using native plants on Hawaiis roadways is to assume that native plants do not require : nutrient enhancement or supplemental water to establish on these sites. The establishment of native plants will : require a detailed ...

  13. Relative competence of native and exotic fish hosts for two generalist native trematodes

    OpenAIRE

    Paterson, Rachel A.; Lal, Aparna; Dale, Marcia; Colin R Townsend; Poulin, Robert; Tompkins, Daniel M.

    2013-01-01

    Exotic fish species frequently acquire native parasites despite the absence of closely related native hosts. They thus have the potential to affect native counterparts by altering native host–parasite dynamics. In New Zealand, exotic brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss have acquired two native trematodes (Telogaster opisthorchis and Stegodexamene anguillae) from their native definitive host (the longfin eel Anguilla dieffenbachii). We used a combination of field sur...

  14. On the Similarities Between Native, Non-native and Translated Texts

    OpenAIRE

    Rabinovich, Ella; Nisioi, Sergiu; Ordan, Noam; Wintner, Shuly

    2016-01-01

    We present a computational analysis of three language varieties: native, advanced non-native, and translation. Our goal is to investigate the similarities and differences between non-native language productions and translations, contrasting both with native language. Using a collection of computational methods we establish three main results: (1) the three types of texts are easily distinguishable; (2) non-native language and translations are closer to each other than each of them is to nativ...

  15. Native Literacy: A Living Language.

    Science.gov (United States)

    Paulsen, Rhonda L.

    2003-01-01

    Aboriginal literacy encompasses oral tradition, culture, language, identity, and world view in addition to the written word, and is a process of lifelong learning, much of which occurs beyond school walls. When defining Native literacy, one must move away from measuring Aboriginal students by Euro-Western definitions and move toward a balanced,…

  16. Learning Styles and Native Americans.

    Science.gov (United States)

    Browne, Dauna Bell

    1990-01-01

    Reviews 5 models of learning or cognitive styles and the concept of brain hemispheric functions. Discusses the right hemisphere dominant learning style of many Native American children. Presents points to consider when modifying curricula or designing a reading program aimed at all learners. Contains 19 references. (SV)

  17. Native herbaceous perennials as ornamentals

    DEFF Research Database (Denmark)

    Larsen, Bjarne; Ørgaard, Marian

    2013-01-01

    Gardening with native perennials is a way to bring nature closer to urban citizens and bring up reflections on nature in a busy world. During three seasons of trialing Salvia pratensis, Dianthus deltoides, Campanula trachelium, Vincetoxicum hirundinaria, Saxifraga granulata, Plantago media and P....

  18. Melting beneath Greenland outlet glaciers and ice streams

    Science.gov (United States)

    Alexander, David; Perrette, Mahé; Beckmann, Johanna

    2015-04-01

    Basal melting of fast-flowing Greenland outlet glaciers and ice streams due to frictional heating at the ice-bed interface contributes significantly to total glacier mass balance and subglacial meltwater flux, yet modelling this basal melt process in Greenland has received minimal research attention. A one-dimensional dynamic ice-flow model is calibrated to the present day longitudinal profiles of 10 major Greenland outlet glaciers and ice streams (including the Jakobshavn Isbrae, Petermann Glacier and Helheim Glacier) and is validated against published ice flow and surface elevation measurements. Along each longitudinal profile, basal melt is calculated as a function of ice flow velocity and basal shear stress. The basal shear stress is dependent on the effective pressure (difference between ice overburden pressure and water pressure), basal roughness and a sliding parametrization. Model output indicates that where outlet glaciers and ice streams terminate into the ocean with either a small floating ice tongue or no floating tongue whatsoever, the proportion of basal melt to total melt (surface, basal and submarine melt) is 5-10% (e.g. Jakobshavn Isbrae; Daugaard-Jensen Glacier). This proportion is, however, negligible where larger ice tongues lose mass mostly by submarine melt (~1%; e.g. Nioghalvfjerdsfjorden Glacier). Modelled basal melt is highest immediately upvalley of the grounding line, with contributions typically up to 20-40% of the total melt for slippery beds and up to 30-70% for resistant beds. Additionally, modelled grounding line and calving front migration inland for all outlet glaciers and ice streams of hundreds of metres to several kilometres occurs. Including basal melt due to frictional heating in outlet glacier and ice stream models is important for more accurately modelling mass balance and subglacial meltwater flux, and therefore, more accurately modelling outlet glacier and ice stream dynamics and responses to future climate change.

  19. Microfungi in the soil beneath common oak and their effect on Armillaria occurrence

    Directory of Open Access Journals (Sweden)

    Hanna Kwaśna

    2014-08-01

    Full Text Available Microfungal assemblages in a soil beneath 30- and 50·year-old oaks and their 2-year-old stumps were studied using the soil dilution plate method. A total of 98 culturable microfungi were isolated. Compared to the living oaks before felling and the control living oaks, the density of Mortierella macrocystis, Penicillium jonczewskii, Pseudogymnoascus roseus Sporothrix schenckii, Tolypoccladiumum inflatum and Umbelopsis vinacea sigificantly inacased in the soil beneath slumps in the 32- and 52-year-old stands. Density of Aspergillus kanagawaensis, Monodictys lepraria, P. daleae and sterile dematiaceous hyphomycetes increased significantly in the 32-year-old stand and Chrysosporium merdarium in the 52·year-old stand. These fungi are known 'stimulants' of Armillaria rhizomorph formation. It is suggested that the increase in density of Armillaria rhizomorph 'stimulants' in a soil beneath oak stumps may increase the possibility of colonization of stumps by Armillaria.

  20. Imaging the midcontinent rift beneath Lake Superior using large aperture seismic data

    Science.gov (United States)

    Trehu, Anne M.; Morel-a-l'Huissier, Patrick; Meyer, R.; Hajnal, Z.; Karl, J.; Mereu, R. F.; Sexton, J.; Shay, J.; Chan, W. K.; Epili, D.; Jefferson, T.; Shih, X. R.; Wendling, S.; Milkereit, B.; Green, A.; Hutchinson, Deborah R.

    1991-01-01

    We present a detailed velocity model across the 1.1 billion year old Midcontinent Rift System (MRS) in central Lake Superior. The model was derived primarily from onshore-offshore large-aperture seismic and gravity data. High velocities obtained within a highly reflective half-graben that was imaged on coincident seismic reflection data demonstrate the dominantly mafic composition of the graben fill and constrain its total thickness to be at least 30km. Strong wide-angle reflections are observed from the lower crust and Moho, indicating that the crust is thickest (55–60km) beneath the axis of the graben. The total crustal thickness decreases rapidly to about 40 km beneath the south shore of the lake and decreases more gradually to the north. Above the Moho is a high-velocity lower crust interpreted to result from syn-rift basaltic intrusion into and/or underplating beneath the Archean lower crust. The lower crust is thickest beneath the axis of the main rift half-graben. A second region of thick lower crust is found approximately 100km north of the axis of the rift beneath a smaller half graben that is interpreted to reflect an earlier stage of rifting. The crustal model presented here resembles recent models of some passive continental margins and is in marked contrast to many models of both active and extinct Phanerozoic continental rift zones. It demonstrates that the Moho is a dynamic feature, since the pre-rift Moho is probably within or above the high-velocity lower crust, whereas the post-rift Moho is defined as the base of this layer. In the absence of major tectonic activity, however, the Moho is very stable, since the large, abrupt variations in crustal thickness beneath the MRS have been preserved for at least a billion years.

  1. Native and Non-Native Perceptions on a Non-Native Oral Discourse in an Academic Setting

    Directory of Open Access Journals (Sweden)

    Kenan Dikilitaş

    2012-07-01

    Full Text Available This qualitative study investigates discourse-level patterns typically employed by a Turkish lecturer based on the syntactic patterns found in the collected data. More specifically, the study aims to reveal how different native and non-native speakers of English perceive discourse patterns used by a non-native lecturer teaching in English. The data gathered from a Turkish lecturer teaching finance, and the interviews both with the lecturer and the students. The lecturer and the students were videotaped and the data was evaluated by content analysis. The results revealed a difference between the way non-native and native speakers evaluate an oral discourse of a non-native lecturer teaching in English. Native speakers of English found the oral performance moderately comprehensible, while non-native speakers found it relatively comprehensible.

  2. Mantle seismic anisotropy beneath NE China and implications for the lithospheric delamination hypothesis beneath the southern Great Xing'an range

    Science.gov (United States)

    Chen, Haichao; Niu, Fenglin; Obayashi, Masayuki; Grand, Stephen P.; Kawakatsu, Hitoshi; John Chen, Y.; Ning, Jieyuan; Tanaka, Satoru

    2017-08-01

    We measured shear wave splitting from SKS data recorded by the transcontinental NECESSArray in NE China to constrain lithosphere deformation and sublithospheric flows beneath the area. We selected several hundreds of high quality SKS/SKKS waveforms from 32 teleseismic earthquakes occurring between 09/01/2009 and 08/31/2011 recorded by 125 broadband stations. These stations cover a variety of tectonic terranes, including the Songliao basin, the Changbaishan mountain range and Zhangguancai range in the east, the Great Xing'an range in the west and the Yanshan orogenic belt in the southwest. We assumed each station is underlaid by a single anisotropic layer and employed a signal-to-noise ratio (SNR) weighted multi-event stacking method to estimate the two splitting parameters (the fast polarization direction φ, and delay time, δt) that gives the best fit to all the SKS/SKKS waveforms recorded at each station. Overall, the measured fast polarization direction lies more or less along the NW-SE direction, which significantly differs from the absolute plate motion direction, but is roughly consistent with the regional extension direction. This suggests that lithosphere deformation is likely the general cause of the observed seismic anisotropy. The most complicated anisotropic structure is observed beneath the southern Great Xing'an range and southwest Songliao basin. The observed large variations in splitting parameters and the seismic tomographic images of the area are consistent with ongoing lithospheric delamination beneath this region.

  3. Non-native marine invertebrates are more tolerant towards environmental stress than taxonomically related native species: results from a globally replicated study.

    Science.gov (United States)

    Lenz, Mark; da Gama, Bernardo A P; Gerner, Nadine V; Gobin, Judith; Gröner, Frederike; Harry, Anil; Jenkins, Stuart R; Kraufvelin, Patrik; Mummelthei, Corinna; Sareyka, Jörg; Xavier, Eduardo A; Wahl, Martin

    2011-10-01

    To predict the risk associated with future introductions, ecologists seek to identify traits that determine the invasiveness of species. Among numerous designated characteristics, tolerance towards environmental stress is one of the most favored. However, there is little empirical support for the assumption that non-native species generally cope better with temporarily unfavorable conditions than native species. To test this concept, we ran five pairwise comparisons between native and non-native marine invertebrates at temperate, subtropical, and tropical sites. We included (natives named first) six bivalves: Brachidontes exustus and Perna viridis, P. perna and Isognomon bicolor, Saccostrea glomerata and Crassostrea gigas, two ascidians: Diplosoma listerianum and Didemnum vexillum as well as two crustaceans: Gammarus zaddachi and G. tigrinus. We simulated acute fluctuations in salinity, oxygen concentration, and temperature, while we measured respiration and survival rates. Under stressful conditions, non-native species consistently showed less pronounced deviations from their normal respiratory performance than their native counterparts. We suggest that this indicates that they have a wider tolerance range. Furthermore, they also revealed higher survival rates under stress. Thus, stress tolerance seems to be a property of successful invaders and could therefore be a useful criterion for screening profiles and risk assessment protocols. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Native and Non-Native Perceptions on a Non-Native Oral Discourse in an Academic Setting

    Science.gov (United States)

    Dikilitas, Kenan; Demir, Bora

    2012-01-01

    This qualitative study investigates discourse-level patterns typically employed by a Turkish lecturer based on the syntactic patterns found in the collected data. More specifically, the study aims to reveal how different native and non-native speakers of English perceive discourse patterns used by a non-native lecturer teaching in English. The…

  5. Magnetolluric Imaging of the Lithosphere beneath the Tibetan Plateau: A Synoptic View

    Science.gov (United States)

    Dong, H.; Wei, W.; Jin, S.; Ye, G.; Jing, J.; Zhang, L.; Jones, A. G.; Xie, C.; Yin, Y.

    2016-12-01

    To better understand the collision and convergence process between India and Asia continent, magnetotelluric (MT) data have been used to image crustal electrical resistivity and to estimate the rheological structure in the south, east and north margin of Tibetan Plateau in the last decades. However, most of these MT data were collected as isolated profiles and insufficient to convey a synoptic view of the Plateau. Recently, the MT data coverage is greatly improved from the 1 by 1 degree SINOPROBE MT array data from 2011-2013. In this study, a three-dimensional (3D) geo-electrical model of the crust and uppermost mantle is derived from the combined broadband and long period array dataset. The resulting model features broadly resistive structure in the upper crust, with the exception of small scale conductors lining along the Yarlung-Zangbo Suture (YZS) and Bangong-Nujiang Suture (BNS). The lower crust consists of widely spread high conductive structures beneath Lhasa and Qiangtang Block except for the southeast part of Tibetan Plateau. Instead of the previous proposed homogenous high conductive layer, these lower crustal conductors are generally N-S directed and perpendicular to the above Cenozoic and Mesozoic sutures. While the lower crustal structures probably indicate partial melts induced by radiogenic heat from the thickened crust, the conductor along the suture zones in the upper crust might imply pathways for deep fluids into the shear zones of YZS and BNS. One of the most prominent feature revealed is the upper mantle conductive sturcture in the central part of Tibet Plateau (85-92°E) accompanied by two resistive regions in the southeast and southwest part of the Plateau. While the southwest resistive zone is broadly consistent with the "flat subduction" region of Indian lithosphere revealed by seismic receiver function study, the conductive middle part of Tibetan Plateau might represent the upper mantle melts induced by the water carried by the steeper

  6. Aloha Aina: Native Hawaiians Fight for Survival

    Science.gov (United States)

    Kealoha, Gard

    1976-01-01

    Discusses the history, values, and cultural background of the native Hawaiian population, asserting that Hawaiians want to recapture and reaffirm the native rights guaranteed by the constitution of Hawaii in 1846. (Author/JM)

  7. Health disparities in the Native Hawaiian homeless.

    Science.gov (United States)

    Yamane, David P; Oeser, Steffen G; Omori, Jill

    2010-06-01

    While it is well accepted that Native Hawaiians have poor health statistics compared to other ethnic groups in Hawaii, it is not well documented if these disparities persist when comparing Native Hawaiian homeless individuals to the general homeless population. This paper examines the Native Hawaiian homeless population living in three shelters on the island of Oahu, to determine if there are significant differences in the frequency of diseases between the Native Hawaiian and non-Native Hawaiian homeless. A retrospective data collection was performed using records from the Hawaii Homeless Outreach and Medical Education (H.O.M.E.) project. Data from 1182 patients was collected as of 12/05/09. Information collected included patient demographics, frequency of self reported diseases, family history of diseases, risk factors, prevalence of chronic diseases, and most common complaints. The data from Native Hawaiians and non-Native Hawaiians were examined for differences and a 1-tail Fisher exact analysis was done to confirm significance. The data reveals that the Native Hawaiian homeless population is afflicted more frequently with asthma and hypertension compared to other ethnic groups. While diabetes constituted more visits to the clinics for Native Hawaiians compared to the non-Native Hawaiians, there was no significant difference in patient reported prevalence of diabetes. The Native Hawaiian homeless also had increased rates of risky behaviors demonstrated by higher past use of marijuana and methamphetamines. Interestingly, there was a lower use of alcohol in the Native Hawaiian homeless and no significant difference between Native Hawaiians and non-native Hawaiians in current use of illicit drugs, which may represent a hopeful change in behaviors. These troubling statistics show that some of the health disparities seen in the general Native Hawaiian population persist despite the global impoverished state of all homeless. Hopefully, these results will aid

  8. Soil water storage and groundwater behaviour in a catenary sequence beneath forest in central Amazonia: I. Comparisons between plateau, slope and valley floor

    Directory of Open Access Journals (Sweden)

    M. G. Hodnett

    1997-01-01

    Full Text Available Soil water storage was monitored in three landscape elements in the forest (plateau, slope and valley floor over a 3 year period to identify differences in sub-surface hydrological response. Under the plateau and slope, the changes of storage were very similar and there was no indication of surface runoff on the slope. The mean maximum seasonal storage change was 156 mm in the 2 m profile but it was clear that, in the dry season, the forest was able to take up water from below 3.6 m. Soil water availability was low. Soil water storage changes in the valley were dominated by the behaviour of a shallow water table which, in normal years, varied between 0.1 m below the surface at the end of the wet season and 0.8 m at the end of the dry season. Soil water storage changes were small because root uptake was largely replenished by groundwater flow towards the stream. The groundwater behaviour is controlled mainly by the deep drainage from beneath the plateau and slope areas. The groundwater gradient beneath the slope indicated that recharge beneath the plateau and slope commences only after the soil water deficits from the previous dry season have been replenished. Following a wet season with little recharge, the water table fell, ceasing to influence the valley soil water storage, and the stream dried up. The plateau and slope, a zone of very high porosity between 0.4 and 1.1 m, underlain by a less conductive layer, is a probable route for interflow during, and for a few hours after, heavy and prolonged rainfall.

  9. Thrust Faulting, Vp, Vs, Vp/Vs and Poisson's Ratios Beneath the Santa Clara Valley, California as Determined from the Santa Clara Seismic Investigation (SCSI)

    Science.gov (United States)

    Catchings, R. D.; Goldman, M. R.; Kiger, L.; Saulter, D.; Wentworth, C.

    2001-12-01

    In December 2000, we conducted an ~20-km-long, southwest-northeast-trending seismic reflection and refraction seismic imaging survey extending from the central Santa Cruz Mountains to the central Santa Clara Valley. The Santa Clara Seismic investigation (SCSI) originated within 0.5 km of the surface trace of the San Andreas fault zone and terminated in downtown San Jose. Between its origin and terminus, the profile crossed the Cupertino Basin and numerous mapped faults, including the Monte Vista thrust fault. Seismic sources were generated by 11 explosions ranging in size from about 12 to 23 kg (25 to 50 lbs.) and were spaced approximately 1 km apart in the central part of the profile. The seismic data were recorded with approximately 400 PASSCAL Texan seismographs, spaced approximately 50 m apart. We inverted first-arrival refractions to determine the P- and S-wave velocity structure of the upper 3.5 km of the crust, and we stacked the seismic reflection data to develop reflection images the upper 10 km of the crust. Our data indicate that P-wave velocities range from about 1.3 km/s near the surface to about 6.0 km/s at varying depths along the profile. Measured S-wave velocities range from about 0.6 km/s near the surface to about 2.6 km/s at varying depths along the profile. Vp/Vs and Poisson's ratios vary from about 1.57 to about 2.10 and from 0.16 to about 0.37, respectively. All velocities and ratios vary laterally and vertically along the profile, but there is an appreciable difference on either side of the Monte Vista fault. Beneath the central Cupertino Basin, the velocity data suggest that sediments (3 km/s) are about 1.2 km deep, thinning to about 600 m deep beneath downtown San Jose and to 0 km deep in the Santa Cruz Mountains. These data show that the Santa Clara Valley and Cupertino Basin sediments are shallower beneath our profile than previously believed. The velocity image also shows a clear low-velocity zone that is most prominent beneath the town

  10. 50 CFR 17.5 - Alaska natives.

    Science.gov (United States)

    2010-10-01

    ..., POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS... threatened wildlife, shall not apply to: (1) Any Indian, Aleut, or Eskimo who is an Alaskan native and who resides in Alaska; or (2) Any non-native permanent resident of an Alaskan native village who is primarily...

  11. Surrounded by Beauty: Arts of Native America.

    Science.gov (United States)

    2002

    Native American languages have no equivalent for the word "art." Yet the objects Native Americans have used and still use suggest that they are a highly spiritual people who create objects of extraordinary beauty. In Native American thought, there is no distinction between what is beautiful or functional, and what is sacred or secular.…

  12. Tamarisk coalition - native riparian plant materials program

    Science.gov (United States)

    Stacy Kolegas

    2012-01-01

    The Tamarisk Coalition (TC), a nonprofit organization dedicated to riparian restoration in the western United States, has created a Native Plant Materials Program to address the identified need for native riparian plant species for use in revegetation efforts on the Colorado Plateau. The specific components of the Native Plant Materials Program include: 1) provide seed...

  13. 34 CFR 300.29 - Native language.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Native language. 300.29 Section 300.29 Education... DISABILITIES General Definitions Used in This Part § 300.29 Native language. (a) Native language, when used with respect to an individual who is limited English proficient, means the following: (1) The language...

  14. Ecological impacts of non-native species

    Science.gov (United States)

    Wilkinson, John W.

    2012-01-01

    Non-native species are considered one of the greatest threats to freshwater biodiversity worldwide (Drake et al. 1989; Allen and Flecker 1993; Dudgeon et al. 2005). Some of the first hypotheses proposed to explain global patterns of amphibian declines included the effects of non-native species (Barinaga 1990; Blaustein and Wake 1990; Wake and Morowitz 1991). Evidence for the impact of non-native species on amphibians stems (1) from correlative research that relates the distribution or abundance of a species to that of a putative non-native species, and (2) from experimental tests of the effects of a non-native species on survival, growth, development or behaviour of a target species (Kats and Ferrer 2003). Over the past two decades, research on the effects of non-native species on amphibians has mostly focused on introduced aquatic predators, particularly fish. Recent research has shifted to more complex ecological relationships such as influences of sub-lethal stressors (e.g. contaminants) on the effects of non-native species (Linder et al. 2003; Sih et al. 2004), non-native species as vectors of disease (Daszak et al. 2004; Garner et al. 2006), hybridization between non-natives and native congeners (Riley et al. 2003; Storfer et al. 2004), and the alteration of food-webs by non-native species (Nystrom et al. 2001). Other research has examined the interaction of non-native species in terms of facilitation (i.e. one non-native enabling another to become established or spread) or the synergistic effects of multiple non-native species on native amphibians, the so-called invasional meltdown hypothesis (Simerloff and Von Holle 1999). Although there is evidence that some non-native species may interact (Ricciardi 2001), there has yet to be convincing evidence that such interactions have led to an accelerated increase in the number of non-native species and cumulative impacts are still uncertain (Simberloff 2006). Applied research on the control, eradication, and

  15. The Alaska Native diabetes program.

    Science.gov (United States)

    Schraer, C D; Mayer, A M; Vogt, A M; Naylor, J; Brown, T L; Hastie, J; Moore, J

    2001-11-01

    To provide optimum health care to indigenous people with diabetes, to prevent diabetes, and to monitor the epidemiology of diabetes and selected complications. The purposes of this paper are to describe the program and to present data that highlights the major problems and successes. Descriptive epidemiology report of diabetes and population service program based on yearly chart review data. Almost half of Alaska Natives with diabetes have no direct access to physicians or hospitals. Health care delivery is now managed by the tribes themselves. Program emphases include maintenance of a population-based registry, formal training for village health aides, physical activity programs, patient education, primary prevention activities and adherence to standards of care to prevent complications. A centralized registry is maintained to assure that epidemiological data is available and patients are not lost to follow-up. Each year a random sample of charts at each major facility is audited against nationally standardized care guidelines. The prevalence of diabetes among Alaska Natives increased 80% over the 13 years from 1985 to 1998 (15.7/1000 to 28.3/1000, age adjusted to U.S. 1980 population). For the years 1986-1998 the incidence rates of lower extremity amputation and end stage renal disease were 6.1/1000 and 2.0/1000 respectively. The level of care provided to Alaska Native patients is comparable to that provided to the general diabetic patient population seen in Alaskan urban clinics. In spite of logistic challenges, care provided to Alaska Native people with diabetes compares favorably to that provided in other settings. Incidence rates of lower extremity amputation and end stage renal disease also remain comparable to or lower than those in other U.S. populations. Many aspects of our system could be extended to other chronic disease programs serving isolated indigenous populations. Primary prevention of diabetes remains a major challenge as life styles change.

  16. The Impact of Focus on Pronoun Resolution in Native and Non-Native Sentence Comprehension

    Science.gov (United States)

    Patterson, Clare; Esaulova, Yulia; Felser, Claudia

    2017-01-01

    Non-native speakers' sensitivity to discourse-level cues in pronoun interpretation has not been widely researched. We carried out three antecedent-choice questionnaire experiments which investigate the impact of focus on within-sentence pronoun resolution in native and non-native speakers of German and native speakers of Russian. Focus was…

  17. Determinants of success in native and non-native listening comprehension: an individual differences approach

    NARCIS (Netherlands)

    Andringa, S.; Olsthoorn, N.; van Beuningen, C.; Schoonen, R.; Hulstijn, J.

    2012-01-01

    The goal of this study was to explain individual differences in both native and non-native listening comprehension; 121 native and 113 non-native speakers of Dutch were tested on various linguistic and nonlinguistic cognitive skills thought to underlie listening comprehension. Structural equation

  18. Chinese College Students' Views on Native English and Non-Native English in EFL Classrooms

    Science.gov (United States)

    Qian, Yang; Jingxia, Liu

    2016-01-01

    With the development of globalization, English is clearly spoken by many more non-native than native speakers, which raises the discussion of English varieties and the debate regarding the conformity to Standard English. Although a large number of studies have shown scholars' attitudes towards native English and non-native English, little research…

  19. LANGUAGE- AND TALKER-DEPENDENT VARIATION IN GLOBAL FEATURES OF NATIVE AND NON-NATIVE SPEECH.

    Science.gov (United States)

    Bradlow, Ann R; Ackerman, Lauren; Burchfield, L Ann; Hesterberg, Lisa; Luque, Jenna; Mok, Kelsey

    2011-01-01

    We motivate and present a corpus of scripted and spontaneous speech in both the native and the non-native language of talkers from various language backgrounds. Using corpus recordings from 11 native English and 11 late Mandarin-English bilinguals we compared speech timing across native English, native Mandarin, and Mandarin-accented English. Findings showed similarities across native Mandarin and native English in speaking rate and in reduction of the number of acoustic relative to orthographic syllables. The two languages differed in silence-to-speech ratio and in the number of words between pauses, possibly reflecting phrase-level structural differences between English and Mandarin. Non-native English had a significantly slower speaking rate and lower rate of syllable reduction than both native English and native Mandarin. But, non-native English was similar to native English in terms of silence-to-speech ratio and was similar to native Mandarin in terms of words per pause. Finally, some talker-specificity in terms of (non)optimal speech timing appeared to transfer from native to non-native speech within the Mandarin-English bilinguals. These findings provide an empirical base for testing how language-dependent, structural features combine with general features of non-native speech production and with talker-dependent features in determining foreign-language speech production.

  20. Determinants of Success in Native and Non-Native Listening Comprehension: An Individual Differences Approach

    Science.gov (United States)

    Andringa, Sible; Olsthoorn, Nomi; van Beuningen, Catherine; Schoonen, Rob; Hulstijn, Jan

    2012-01-01

    The goal of this study was to explain individual differences in both native and non-native listening comprehension; 121 native and 113 non-native speakers of Dutch were tested on various linguistic and nonlinguistic cognitive skills thought to underlie listening comprehension. Structural equation modeling was used to identify the predictors of…

  1. Constraining P-wave velocity variations in the upper mantle beneath Southeast Asia

    NARCIS (Netherlands)

    Li, Chang; Hilst, R.D. van der; Toksöz, M. Nafi

    2006-01-01

    We have produced a P-wave model of the upper mantle beneath Southeast (SE) Asia from reprocessed short period International Seismological Centre (ISC) P and pP data, short period P data of the Annual Bulletin of Chinese Earthquakes (ABCE), and long period PP-P data.We used 3D sensitivity kernels

  2. Constraining spatial variations in P-wave velocity in the upper mantle beneath SE Asia

    NARCIS (Netherlands)

    Li, C.; Hilst, R.D. van der; Toksoz, N.M.

    2006-01-01

    We have produced a P-wave model of the upper mantle beneath Southeast (SE) Asia from reprocessed short period International Seismological Centre (ISC) P and pP data, short period P data of the Annual Bulletin of Chinese Earthquakes (ABCE), and long period PP-P data.We used 3D sensitivity kernels

  3. Assessing the impact of modern recharge on a sandstone aquifer beneath a suburb of Doncaster, UK

    OpenAIRE

    Morris, Brian L.; Darling, W. George; Cronin, Aidan A; Rueedi, Joerg; Whitehead, Emily J.; Gooddy, Daren C.

    2006-01-01

    A major water quality issue in urban areas underlain by a productive aquifer is the impact of modern recharge. Using a variety of sample sources including multi-level boreholes, detectable concentrations of CFCs and SF6 have been found throughout the upper 50 m of the saturated aquifer beneath a suburb of Doncaster, UK, indicating that modern (

  4. Recharge Rates and Chemistry Beneath Playas of the High Plains Aquifer - A Literature Review and Synthesis

    Science.gov (United States)

    Gurdak, Jason J.; Roe, Cassia D.

    2009-01-01

    Playas are ephemeral, closed-basin wetlands that are important zones of recharge to the High Plains (or Ogallala) aquifer and critical habitat for birds and other wildlife in the otherwise semiarid, shortgrass prairie and agricultural landscape. The ephemeral nature of playas, low regional recharge rates, and a strong reliance on ground water from the High Plains aquifer has prompted many questions regarding the contribution of recharge from playas to the regional aquifer. To address these questions and concerns, the U.S. Geological Survey, in cooperation with the Playa Lakes Joint Venture, present a review and synthesis of the more than 175 publications about recharge rates and chemistry beneath playas and interplaya settings. Although a number of questions remain regarding the controls on recharge rates and chemistry beneath playas, the results from most published studies indicate that recharge rates beneath playas are substantially (1 to 2 orders of magnitude) higher than recharge rates beneath interplaya settings. The synthesis presented here supports the conceptual model that playas are important zones of recharge to the High Plains aquifer and are not strictly evaporative pans. The major findings of this synthesis yield science-based implications for the protection and management of playas and ground-water resources of the High Plains aquifer and directions for future research.

  5. Upper-mantle shear velocity beneath eastern Australia from inversion of waveforms from SKIPPY portable arrays

    NARCIS (Netherlands)

    Zielhuis, A.; Hilst, R.D. van der

    1996-01-01

    In 1993, the Research School of Earth Sciences of the Australian National University commenced a nationwide seismometry project, SKIPPY, for a comprehensive study of the upper mantle beneath the Australian continent. We applied a waveform inversion technique to broad-band data recorded while the

  6. Slab remnants beneath the Baja California peninsula : Seismic constraints and tectonic implications

    NARCIS (Netherlands)

    Paulssen, Hanneke; de Vos, Denise

    2017-01-01

    The formation of the Gulf of California has been related to the cessation of subduction of the Guadalupe and Magdalena microplates. Various studies have identified features that point to the presence of a slab remnant beneath the Baja California peninsula, but its depth range and lateral extent

  7. Structure and evolution of subducted lithosphere beneath the Sunda arc, Indonesia

    NARCIS (Netherlands)

    Widiyantoro, Sri; Hilst, R.D. van der

    1996-01-01

    Tomographic imaging reveals seismic anomalies beneath the Sunda island arc, Indonesia, that suggest that the lithospheric slab penetrates to a depth of at least 1500 kilometers. The Sunda slab forms the eastern end of a deep anomaly associated with the past subduction of the plate underlying the

  8. Tectonic implications of tomographic images of subducted lithosphere beneath northwestern South America

    NARCIS (Netherlands)

    Hilst, R.D. van der; Mann, P.

    1994-01-01

    We used seismic tomography to investigate the complex structure of the upper mantle below northwestern South America. Images of slab structure not delineated by previous seismicity studies help us to refine existing tectonic models of subducted Caribbean-Pacific lithosphere beneath the study area.

  9. Sampling and Hydrogeology of the Vadose Zone Beneath the 300 Area Process Ponds

    Energy Technology Data Exchange (ETDEWEB)

    Bjornstad, Bruce N.

    2004-08-31

    Four open pits were dug with a backhoe into the vadose zone beneath the former 300 Area Process Ponds in April 2003. Samples were collected about every 2 feet for physical, chemical, and/or microbiological characterization. This reports presents a stratigraphic and geohydrologic summary of the four excavations.

  10. Seismic imaging of a mid-lithospheric discontinuity beneath Ontong Java Plateau

    Science.gov (United States)

    Tharimena, Saikiran; Rychert, Catherine A.; Harmon, Nicholas

    2016-09-01

    Ontong Java Plateau (OJP) is a huge, completely submerged volcanic edifice that is hypothesized to have formed during large plume melting events ∼90 and 120 My ago. It is currently resisting subduction into the North Solomon trench. The size and buoyancy of the plateau along with its history of plume melting and current interaction with a subduction zone are all similar to the characteristics and hypothesized mechanisms of continent formation. However, the plateau is remote, and enigmatic, and its proto-continent potential is debated. We use SS precursors to image seismic discontinuity structure beneath Ontong Java Plateau. We image a velocity increase with depth at 28 ± 4 km consistent with the Moho. In addition, we image velocity decreases at 80 ± 5 km and 282 ± 7 km depth. Discontinuities at 60-100 km depth are frequently observed both beneath the oceans and the continents. However, the discontinuity at 282 km is anomalous in comparison to surrounding oceanic regions; in the context of previous results it may suggest a thick viscous root beneath OJP. If such a root exists, then the discontinuity at 80 km bears some similarity to the mid-lithospheric discontinuities (MLDs) observed beneath continents. One possibility is that plume melting events, similar to that which formed OJP, may cause discontinuities in the MLD depth range. Plume-plate interaction could be a mechanism for MLD formation in some continents in the Archean prior to the onset of subduction.

  11. Crustal thickness, discontinuity depth, and upper mantle structure beneath southern Africa: constraints from body wave conversions

    NARCIS (Netherlands)

    Stankiewicz, Jacek; Che, Sébastien; Hilst, R.D. van der; Wit, Maarten J. de

    2002-01-01

    The technique of receiver function analysis is applied to the study of crustal and upper mantle structures beneath the Kaapvaal craton in southern Africa and its surroundings. Seismic data were recorded by the seismic array of 82 sites deployed from April 1997 to April 1999 across southern Africa,

  12. The crustal structure beneath The Netherlands derived from ambient seismic noise

    NARCIS (Netherlands)

    Yudistira, Tedi|info:eu-repo/dai/nl/314410597; Paulssen, Hanneke|info:eu-repo/dai/nl/073584436; Trampert, Jeannot|info:eu-repo/dai/nl/304829250

    2017-01-01

    This work presents the first comprehensive 3-D model of the crust beneath The Netherlands. To obtain this model, we designed the NARS-Netherlands project, a dense deployment of broadband stations in the area. Rayleigh and Love wave group velocity dispersion was measured from ambient noise

  13. Formation of heterogeneous magmatic series beneath North Santorini, South Aegean island arc

    DEFF Research Database (Denmark)

    Bailey, John C; Jensen, E.S.; Hansen, A.

    2008-01-01

    magma formation beneath North Santorini throughout its 500 ka history is attributed to variable transfer of sedimentary components - either terrigenous or pelagic, as bulk sediments or high-temperature partial melts rather than fluids or low-temperature partial melts - from a rupture zone...

  14. Topography of the crust-mantle boundary beneath the Black Sea Basin.

    NARCIS (Netherlands)

    Starostenkp, V.; Buryanov, V.; Makarenko, I.; Rusakov, O.M.; Stephenson, R.A.; Nikishin, A.M.; Georgiev, G.; Gerasimov, M.; Dimitriu, R.; Legostaeva, O.V.; Pchelarov, V.; Sava, C.S.

    2004-01-01

    A map of Moho depth for the Black Sea and its immediate surroundings has been inferred from 3-D gravity modelling, and crustal structure has been clarified. Beneath the basin centre, the thickness of the crystalline layer is similar to that of the oceanic crust. In the Western and Eastern Black Sea

  15. Optimal control of native predators

    Science.gov (United States)

    Martin, Julien; O'Connell, Allan F.; Kendall, William L.; Runge, Michael C.; Simons, Theodore R.; Waldstein, Arielle H.; Schulte, Shiloh A.; Converse, Sarah J.; Smith, Graham W.; Pinion, Timothy; Rikard, Michael; Zipkin, Elise F.

    2010-01-01

    We apply decision theory in a structured decision-making framework to evaluate how control of raccoons (Procyon lotor), a native predator, can promote the conservation of a declining population of American Oystercatchers (Haematopus palliatus) on the Outer Banks of North Carolina. Our management objective was to maintain Oystercatcher productivity above a level deemed necessary for population recovery while minimizing raccoon removal. We evaluated several scenarios including no raccoon removal, and applied an adaptive optimization algorithm to account for parameter uncertainty. We show how adaptive optimization can be used to account for uncertainties about how raccoon control may affect Oystercatcher productivity. Adaptive management can reduce this type of uncertainty and is particularly well suited for addressing controversial management issues such as native predator control. The case study also offers several insights that may be relevant to the optimal control of other native predators. First, we found that stage-specific removal policies (e.g., yearling versus adult raccoon removals) were most efficient if the reproductive values among stage classes were very different. Second, we found that the optimal control of raccoons would result in higher Oystercatcher productivity than the minimum levels recommended for this species. Third, we found that removing more raccoons initially minimized the total number of removals necessary to meet long term management objectives. Finally, if for logistical reasons managers cannot sustain a removal program by removing a minimum number of raccoons annually, managers may run the risk of creating an ecological trap for Oystercatchers.

  16. Radial Viscous Fingering and its Surface Expression due to Convective Upwelling Beneath North Atlantic Ocean

    Science.gov (United States)

    White, N. J.; Schoonman, C. M.

    2016-12-01

    The Icelandic mantle plume has had a significant influence on the geologic and oceanographic evolution of the North Atlantic Ocean during Cenozoic times. Full-waveform tomographic imaging of this region show that the planform of this plume has a complex irregular shape with significant shear wave velocity anomalies lying beneath the lithospheric plates between 100 and 200 km depth. The planform of these anomalies suggests that five or more horizontal fingers extend radially beneath the fringing continental margins. The best-imaged fingers lie beneath the British Isles and beneath western Norway where significant crustal isostatic departures have been measured. Here, we propose that these radial fingers are generated by a phenomenon known as the Saffman-Taylor instability. Experimental and theoretical analyses show that radial, miscible viscous fingering occurs when a less viscous fluid is injected into a more viscous fluid. The wavelength and number of fingers are controlled by the mobility (i.e. the ratio of viscosities), by the Peclet number (i.e. the ratio of advective and diffusive processes), and by the thickness of the horizontal layer into which fluid is injected. We have combined shear wave velocity estimates with residual depth measurements around the Atlantic margins to calculate the planform distribution of temperature and viscosity within an asthenospheric layer beneath the lithospheric plates. Our calculations suggest that the mobility is 20-50, that the Peclet number is O(104, and that the asthenospheric channel is 150 ± 50 km thick. The existence and form of viscous fingering is consistent with experimental observations and with linear stability analysis. A useful rule of thumb is that the wavelength of viscous fingering is 5 ± 1 times the thickness of the horizontal layer. Our proposal support the notion that dynamic topography of the Earth's surface can be influenced by rapid horizontal flow within spatially evolving asthenospheric fingers.

  17. Combined multi-scale characterization of a sedimentary structure beneath a river embankment to expand conventional flood protection

    Science.gov (United States)

    Vienken, T.; Kreck, M.; Hausmann, J.; Werban, U.

    2011-12-01

    Embankments along rivers and streams are a common measure of constructional flood protection in Germany. At a test site along the River Mulde near the town of Löbnitz, Saxony, Germany, aerial photographs reveal the presence of a surface near underground sedimentary structure that crosses the embankment. This sedimentary structure is suspected to consist of sedimentary channel deposits that may serve as preferential flow path during seasonal flooding, leading to increased water propagation beneath the embankment. During normal water level, this structure is within the unsaturated zone. Geophysical techniques, GPR and geoelectrics, were used to characterize the extent of the sedimentary structure. At selected points high resolution vertical one-dimensional profiles of geotechnical and hydrogeological sediment properties were measured using minimum invasive direct push technology. The combination of multi-scale data allows the characterization of the identified sedimentary structure at the test site regarding its extent and hydraulic properties in respect to the fluviatile floodplain deposits present at the test site along a 500m transect. In this study, the combination of non-invasive geophysics and minimum invasive direct push technology provided high resolution geospatial information of a sedimentary regime, which could not have been achieved with conventional characterization methods, e.g. retrieval and analysis of soil samples, regarding resolution and work efficiency.

  18. Crustal structure beneath the middle-lower Yangtze metallogenic belt in East China: Constraints from passive source seismic experiment on the Mesozoic intra-continental mineralization

    Science.gov (United States)

    Shi, Danian; Lü, Qingtian; Xu, Wenyi; Yan, Jiayong; Zhao, Jinhua; Dong, Shuwen; Chang, Yinfo

    2013-10-01

    To understand the formation and the tectonic process of the Mesozoic middle-lower Yangtze metallogenic belt (YMB), the SinoProbe program deployed a quasi-linear passive source seismic array across the belt. We performed receiver function profiling and measurement of shear-wave splitting parameters with the collected data. Our results show that the Moho depth varies significantly along the profile and that a “mantle uplift” exists right beneath the YMB. We also found that the lower crust of the YMB is different from that of its adjacent areas in structure on the receiver function profile. It possesses seismic anisotropy with direction roughly parallel to the belt. Our SKS/SKKS shear-wave splitting results also show similar belt-parallel azimuthal anisotropy right beneath the YMB. We interpret the seismic anisotropy in the lower crust of the YMB as the result of mineral crystal alignment caused by melting and belt-parallel flow in the Mesozoic ore-forming process. Besides, we observed a nearly south-dipping converter extending from shallow to lower crust beneath the Hefei Basin, which most possibly resulted from the Mesozoic crustal extension. We interpret the “mantle uplift” and the crustal extensional structures to be consequences of asthenospheric upwelling during the Mesozoic ore-forming process. Our results suggest that the lower crust of the YMB was most likely one part of the multi-level metallogenic magma system in the Mesozoic magmatism and mineralization processes, and the formation of the metallogenic belt to be a result much similar to the MASH (Melting, Assimilation, Storage and Homogenization; cf. Hildreth and Moorbath, 1988; Richards, 2003) process. First, the asthenospheric upwelling resulted in a crustal extensional environment; then the melts from the upwelling asthenosphere intruded into the lower crust of the YMB, and assimilation occurred when they mixed with in situ lower crustal materials, which led to the formation of adakitic

  19. Data Profiling

    OpenAIRE

    Hladíková, Radka

    2010-01-01

    Title: Data Profiling Author: Radka Hladíková Department: Department of Software Engineering Supervisor: Ing. Vladimír Kyjonka Supervisor's e-mail address: Abstract: This thesis puts mind on problems with data quality and data profiling. This Work analyses and summarizes problems of data quality, data defects, process of data quality, data quality assessment and data profiling. The main topic is data profiling as a process of researching data available in existing...

  20. Chinese College Students’ Views on Native English and Non-native English in EFL Classrooms

    OpenAIRE

    Yang Qian; Liu Jingxia

    2016-01-01

    With the development of globalization, English is clearly spoken by many more non-native than native speakers, which raises the discussion of English varieties and the debate regarding the conformity to Standard English. Although a large number of studies have shown scholars’ attitudes towards native English and non-native English, little research is conducted from the point of college students until recently. This paper focuses on Chinese college students’ perceptions of native English and n...

  1. Native and Non-native English Teachers' Perceptions of their Professional Identity: Convergent or Divergent?

    OpenAIRE

    Zia Tajeddin; Aylar Adeh

    2016-01-01

    There is still a preference for native speaker teachers in the language teaching profession, which is supposed to influence the self-perceptions of native and nonnative teachers. However, the status of English as a globalized language is changing the legitimacy of native/nonnative teacher dichotomy. This study sought to investigate native and nonnative English-speaking teachers’ perceptions about native and nonnative teachers’ status and the advantages and disad...

  2. Depths to major density contrats beneath the West African rift system in Nigeria and Cameroon based on the spectral analysis of gravity data

    Science.gov (United States)

    Fairhead, J. D.; Okereke, C. S.

    Estimates of depth to major density contrats within the lithosphere have been made, over the West African Rift System and adjacent basement areas in Nigeria and Cameroon, based on the spectral analysis of the Bouguer gravity field. The study reveals that three main density discontinuities occur in the depth ranges 7 to 12 km, 19 to 30 km and 80 to 93 km. The shallow crustal density discontinuities reflect a range of geological structures associated with the rift zones, shear zones and cratonic margins. The 19 to 30 km depth range is in good agreement with the Moho' depths determined by seismic refraction studies beneath and to the south of the Yola Rift in Cameroon and by East-West gravity modelling profiles across the Benue Trough in Nigeria. The deepest density discontinuities observed at 80 to 93 km depth are compatible with the presence of an anomalous low velocity upper mantle structure at these depths deduced from the inversion of teleseismic travel time residuals. The spectral analysis of gravity data can thus provide reliable first order estimates of depth to density discontinuities within the lithosphere beneath a rifted continental plate where such density variations would be expected.

  3. (En)Countering Native-speakerism: Global Perspectives

    National Research Council Canada - National Science Library

    Graciela Rojo Arce

    2016-01-01

    ...)Countering Native-speakerism: Global Perspectives is a compilation of Native and Non-Native English Teachers' perceptions towards native-speakerism ideologies inside the Teachers of English to Speakers of other Languages (TESOL) field...

  4. Soil Organic Carbon under Native and Cropped Land Use

    Science.gov (United States)

    Follett, R. F.; Kimble, J. M.; Pruessner, E.; Samson-Liebig, S.; Waltman, S. W.

    2009-12-01

    Soil samples were collected from soil pits at depths of 0 to 5 and 5 to 10 cm and by genetic soil-horizon thereafter, with data reported to 1 m depth. Weights of soil organic carbon (SOC) by profile layer were calculated using thicknesses, bulk densities, and C analyses data. Recalculation for discrete depth increments from the horizon data was necessary to statistically analyze and report the SOC for depth increments of 0 to 10, 10 to 20, 20 to 30, 30 to 60, and 60 to 100 cm. The Soil Extent Mapping Tool of the NRCS provided a snapshot, by soil survey area, of where and the size of the areas by county of the soil series sampled in this study. Estimated combined acreage of the 21 soil series, for these 30 paired native and cropped sites, was 9 Mha within 18 states. To estimate the equivalent amount of SOC represented required that the data be area-weighted and statistically analyzed. On an area-weighted basis 131,890 and 98,470 kg SOC per ha were found in the top 100 cm of the native and cropped sites, respectively. Comparison of the difference of ‘native minus cropped’ as an estimate of area weighted SOC losses from cropped soils in for the 0-to 100 cm depth was that 43, 58, and 75% of the total was from the 0-to 10, 0-to 20, and 0-to 30 cm depths, respectively. The area-weighted average-decrease of SOC within the 0-to 100 cm depth (native minus cropped) was 3.0 Tg SOC across 9 Mha. If similar differences exist between native vs. cropped land across the entire 137.6 Mha of US cropland, a total SOC loss would be equivalent to 46 Tg SOC, or equivalent to 170 Tg (0.17 Pg) CO2.

  5. Evaluating Application Scenarioswith React Native : A Comparative Study between Native and ReactNative Development

    OpenAIRE

    Lelli, Andreas; Bostrand, Viktor

    2016-01-01

    There are multiple ways of creating a modern mobile application and differentcombinations of programming languages and tools can be used to suite specificneeds.Typically, open market products need to support various platforms which, due tomultiple code bases, might lead to difficulties with maintenance and new featuredeployment.React Native is a JavaScript library, announced by Facebook in 2015, that provides auniversal pattern for creating mobile applications for Android and iOS. Theframewor...

  6. New tomographic images of P- , S- wave velocity and Q on the Philippine Sea Slab beneath Tokyo: Implication to seismotectonics and seismic hazard in the Tokyo metropolitan region

    Science.gov (United States)

    Hirata, Naoshi; Sakai, Shin'ichi; Nakagawa, Shigeki; Panayotopoulos, Yannis; Ishikawa, Masahiro; Sato, Hiroshi; Kasahara, Keiji; Kimura, Hisanor; Honda, Ryou

    2013-04-01

    The Central Disaster Management Council of Japan estimates the next great M7+ earthquake in the Tokyo metropolitan region will cause 11,000 fatalities and 112 trillion yen (1 trillion US) economic loss at worst case if it occur beneath northern Tokyo bay with M7.3. However, the estimate is based on a source fault model by conventional studies about the PSP geometry. To evaluate seismic hazard due to the great quake we need to clarify the geometry of PSP and also the Pacific palate (PAP) that subducs beneath PSP. We identify those plates with use of seismic tomography and available deep seismic reflection profiling and borehole data in southern Kanto area. We deployed about 300 seismic stations in the greater Tokyo urban region under the Special Project for Earthquake Disaster Mitigation in Tokyo Metropolitan Area. We obtain clear P- and S- wave velocity (Vp and Vs) and Q tomograms which show a clear image of PSP and PAP. A depth to the top of PSP, 20 to 30 kilometer beneath northern part of Tokyo bay, is about 10 km shallower than previous estimates based on the distribution of seismicity (Ishida, 1992). This shallower plate geometry changes estimations of strong ground motion for seismic hazards analysis within the Tokyo region. Based on elastic wave velocities of rocks and minerals, we interpreted the tomographic images as petrologic images. Tomographic images revealed the presence of two stepwise velocity increase of the top layer of the subducting PSP slab. Rock velocity data reveals that subducting PSP crust transforms from blueschists to amphibolites at depth of 30km and amphibolites to eclogites at depth of 50km, which suggest that dehydration reactions occurs in subducting crust of basaltic compositions during prograde metamorphism and water is released from the subducting PSP crust. Tomograms show evidence for a low-velocity zone (LVZ) beneath the area just north of Tokyo bay. A Q tomogram show a low Q zone in PSP slab. We interpret the LVZ as a

  7. Bedrock topography beneath uppermost part of Aletsch glacier, Central Swiss Alps, revealed from cosmic-ray muon radiography

    Science.gov (United States)

    Nishiyama, Ryuichi; Ariga, Akitaka; Ariga, Tomoko; Käser, Samuel; Lechmann, Alessandro; Mair, David; Scampoli, Paola; Vladymyrov, Mykhailo; Ereditato, Antonio; Schlunegger, Fritz

    2017-04-01

    In mountainous landscapes such as the Central Alps of Europe, the bedrock topography is one of the most interesting subjects of study since it separates the geological substratum (bedrock) from the overlying unconsolidated units (ice). The geometry of the bedrock topography puts a tight constraint on the erosional mechanism of glaciers. In previous studies, it has been inferred mainly from landscapes where glaciers have disappeared after the termination of the last glacial epoch. However, the number of studies with a focus on the structure beneath active glaciers is limited, because existing exploration methods have limitation in resolution and mobility. The Eiger-μ project proposes a new technology, called muon radiography, to investigate the bedrock geometry beneath active glaciers. The muon radiography is a recent technique that relies on the high penetration power of muon components in natural cosmic rays. Specifically, one can resolve the internal density profile of a gigantic object by measuring the attenuation rate of the intensity of muons after passing through it, as in medical X-ray diagnostic. This technique has been applied to many fields such as volcano monitoring (eg. Ambrosino et al., 2015; Jourde et al., 2016; Nishiyama et al., 2016), detection of seismic faults (eg. Tanaka et al., 2011), inspection inside nuclear reactors, etc. The first feasibility test of the Eiger-μ project has been performed at Jungfrau region, Central Swiss Alps, Switzerland. We installed cosmic-ray detectors consisting of emulsion films at three sites along the Jungfrau railway tunnel facing Aletsch glacier (Jungfraufirn). The detectors stayed 47 days in the tunnel and recorded the tracks of muons which passed through the glacier and bedrock (thickness is about 100 m). Successively the films were chemically developed and scanned at University of Bern with microscopes originally developed for the analysis of physics experiments on neutrino oscillation. The analysis of muon

  8. Native Speakers in Linguistic Imperialism

    DEFF Research Database (Denmark)

    Phillipson, Robert

    2016-01-01

    is recognised as desirable by some British experts, the native speakers in question seldom have this key qualification. This is even the case when the host country (Brunei) aims at bilingual education. It is unlikely that the host countries are getting value for money. Whether the UK and other ‘English...... learning and teaching, and the inappropriate qualifications of those sent to education systems when they are unfamiliar with the learners’ languages, cultures, and pedagogical traditions. Whether the schemes involved constitute linguistic imperialismis analysed. Whereas the need for multilingual competence...

  9. Aeromagnetic evidence for a volcanic caldera(?) complex beneath the divide of the West Antarctic Ice Sheet

    Science.gov (United States)

    Behrendt, John C.; Finn, C.A.; Blankenship, D.; Bell, R.E.

    1998-01-01

    A 1995-96 aeromagnetic survey over part of the Sinuous Ridge (SR) beneath the West Antarctic Ice Sheet (WAIS) divide shows a 70-km diameter circular pattern of 400-1200-nT anomalies suggesting one of the largest volcanic caldera(?) complexes on earth. Radar-ice-sounding (RIS) shows the northern part of this pattern overlies the SR, and extends south over the Bentley Subglacial Trench (BST). Modeled sources of all but one the caldera(?) anomalies are at the base of <1-2-km thick ice and their volcanic edifices have been glacially removed. The exception is a 700-m high, 15-km wide 'volcano' producing an 800-nT anomaly over the BST. 'Intrusion' of this 'volcano' beneath 3 km of ice probably resulted in pillow basalt rather than easily removed hyaloclastite erupted beneath thinner ice. The background area (-300 to -500-nT) surrounding the caldera(?) is possibly caused by a shallow Curie isotherm. We suggest uplift of the SR forced the advance of the WAIS.A 1995-96 aeromagnetic survey over part of the Sinuous Ridge (SR) beneath the West Antarctic Ice Sheet (WAIS) divide shows a 70-km diameter circular pattern of 400-1200-nT anomalies suggesting one of the largest volcanic caldera(?) complexes on earth. Radar-ice-sounding (RIS) shows the northern part of this pattern overlies the SR, and extends south over the Bentley Subglacial Trench (BST). Modeled sources of all but one the caldera(?) anomalies are at the base of < 1-2-km thick ice and their volcanic edifices have been glacially removed. The exception is a 700-m high, 15-km wide 'volcano' producing an 800-nT anomaly over the BST. 'Intrusion' of this 'volcano' beneath 3 km of ice probably resulted in pillow basalt rather than easily removed hyaloclastite erupted beneath thinner ice. The background area (-300 to -500-nT) surrounding the caldera(?) is possibly caused by a shallow Curie isotherm. We suggest uplift of the SR forced the advance of the WAIS.

  10. Native Chicken Production in Indonesia: A Review

    Directory of Open Access Journals (Sweden)

    C. Hidayat

    2015-02-01

    Full Text Available Indonesia is a country rich in native chicken genetic resources. There are 31 native chicken breed in Indonesia. Native chicken farming was developed for decades. In early period of 1907’s, mostly farmers reared their native chicken by traditional system (about 80%. In 1980s until now, the number of native chicken farmers which rear native chicken by semi intensive and intensive system have been increasing. These rearing system changing have significantly increased the native chicken productivity. The major constraints for the development of native chicken i.e. low growth rate, risks of high mortality, low egg production. Many research results stated that improving in breeding, feeding and management aspect will increase native chicken production. The information and data contained in this paper is the result of study literature for scientific papers, either in the form of journals, books, or proceedings, and livestock statistics books. This paper is made to support the development of native chickens in Indonesia.

  11. Native and Non-Native Perceptions on a Non-Native Oral Discourse in an Academic Setting

    OpenAIRE

    Kenan Dikilitaş; Bora Demir

    2012-01-01

    This qualitative study investigates discourse-level patterns typically employed by a Turkish lecturer based on the syntactic patterns found in the collected data. More specifically, the study aims to reveal how different native and non-native speakers of English perceive discourse patterns used by a non-native lecturer teaching in English. The data gathered from a Turkish lecturer teaching finance, and the interviews both with the lecturer and the students. The lecturer and the students were ...

  12. Temperature-profile methods for estimating percolation rates in arid environments

    Science.gov (United States)

    Constantz, Jim; Tyler, Scott W.; Kwicklis, Edward

    2003-01-01

    Percolation rates are estimated using vertical temperature profiles from sequentially deeper vadose environments, progressing from sediments beneath stream channels, to expansive basin-fill materials, and finally to deep fractured bedrock underlying mountainous terrain. Beneath stream channels, vertical temperature profiles vary over time in response to downward heat transport, which is generally controlled by conductive heat transport during dry periods, or by advective transport during channel infiltration. During periods of stream-channel infiltration, two relatively simple approaches are possible: a heat-pulse technique, or a heat and liquid-water transport simulation code. Focused percolation rates beneath stream channels are examined for perennial, seasonal, and ephemeral channels in central New Mexico, with estimated percolation rates ranging from 100 to 2100 mm d−1 Deep within basin-fill and underlying mountainous terrain, vertical temperature gradients are dominated by the local geothermal gradient, which creates a profile with decreasing temperatures toward the surface. If simplifying assumptions are employed regarding stratigraphy and vapor fluxes, an analytical solution to the heat transport problem can be used to generate temperature profiles at specified percolation rates for comparison to the observed geothermal gradient. Comparisons to an observed temperature profile in the basin-fill sediments beneath Frenchman Flat, Nevada, yielded water fluxes near zero, with absolute values <10 mm yr−1 For the deep vadose environment beneath Yucca Mountain, Nevada, the complexities of stratigraphy and vapor movement are incorporated into a more elaborate heat and water transport model to compare simulated and observed temperature profiles for a pair of deep boreholes. Best matches resulted in a percolation rate near zero for one borehole and 11 mm yr−1 for the second borehole.

  13. The Native American Dream: Entrepreneurs Pursue Their Passion and Self Sufficiency

    Science.gov (United States)

    Deweese, Sarah; Macleod, Malcolm

    2007-01-01

    The article profiles Native Americans in the United States who own their own businesses. Kim Johnson, a member of the Fort Peck Assiniboine and Sioux Tribes, owns KC's Oil and Lube, a business on the Fort Peck Reservation in Montana. Johnson spoke to a business teacher at the "tribal college", received a scholarship, and took several…

  14. Reconstructing Native American Population History

    Science.gov (United States)

    Reich, David; Patterson, Nick; Campbell, Desmond; Tandon, Arti; Mazieres, Stéphane; Ray, Nicolas; Parra, Maria V.; Rojas, Winston; Duque, Constanza; Mesa, Natalia; García, Luis F.; Triana, Omar; Blair, Silvia; Maestre, Amanda; Dib, Juan C.; Bravi, Claudio M.; Bailliet, Graciela; Corach, Daniel; Hünemeier, Tábita; Bortolini, Maria-Cátira; Salzano, Francisco M.; Petzl-Erler, María Luiza; Acuña-Alonzo, Victor; Aguilar-Salinas, Carlos; Canizales-Quinteros, Samuel; Tusié-Luna, Teresa; Riba, Laura; Rodríguez-Cruz, Maricela; Lopez-Alarcón, Mardia; Coral-Vazquez, Ramón; Canto-Cetina, Thelma; Silva-Zolezzi, Irma; Fernandez-Lopez, Juan Carlos; Contreras, Alejandra V.; Jimenez-Sanchez, Gerardo; Gómez-Vázquez, María José; Molina, Julio; Carracedo, Ángel; Salas, Antonio; Gallo, Carla; Poletti, Giovanni; Witonsky, David B.; Alkorta-Aranburu, Gorka; Sukernik, Rem I.; Osipova, Ludmila; Fedorova, Sardana; Vasquez, René; Villena, Mercedes; Moreau, Claudia; Barrantes, Ramiro; Pauls, David; Excoffier, Laurent; Bedoya, Gabriel; Rothhammer, Francisco; Dugoujon, Jean Michel; Larrouy, Georges; Klitz, William; Labuda, Damian; Kidd, Judith; Kidd, Kenneth; Rienzo, Anna Di; Freimer, Nelson B.; Price, Alkes L.; Ruiz-Linares, Andrés

    2013-01-01

    The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved1–5. One contentious issue is whether the settlement occurred via a single6–8 or multiple streams of migration from Siberia9–15. The pattern of dispersals within the Americas is also poorly understood. To address these questions at higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. We show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call “First American”. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan-speakers on both sides of the Panama Isthmus, who have ancestry from both North and South America. PMID:22801491

  15. Native Americans: Where in Environmental Justice Research?

    Science.gov (United States)

    Vickery, Jamie; Hunter, Lori M

    While the last two decades have seen important theoretical, empirical, and policy advancements in environmental justice generally, much remains to be done regarding Native Americans. Unique political and cultural dynamics shape the study and pursuit of environmental justice (EJ) in Native American communities. This review summarizes Native American EJ issues based on a cross-disciplinary search of over 60 publications. In so doing, we discuss the unique nature of Native American EJ in terms of conducting research and working toward reducing the continuation of historical trauma associated with environmental ills, the types of strategies used in Native American EJ research, and issues of Native American climate justice. We conclude with discussion of remaining knowledge gaps and future research needs.

  16. Louisville seamount subduction and its implication on mantle flow beneath the central Tonga-Kermadec arc.

    Science.gov (United States)

    Timm, Christian; Bassett, Daniel; Graham, Ian J; Leybourne, Matthew I; de Ronde, Cornel E J; Woodhead, Jon; Layton-Matthews, Daniel; Watts, Anthony B

    2013-01-01

    Subduction of intraplate seamounts beneath a geochemically depleted mantle wedge provides a seldom opportunity to trace element recycling and mantle flow in subduction zones. Here we present trace element and Sr, Nd and Pb isotopic compositions of lavas from the central Tonga-Kermadec arc, west of the contemporary Louisville-Tonga trench intersection, to provide new insights into the effects of Louisville seamount subduction. Elevated (206)Pb/(204)Pb, (208)Pb/(204)Pb, (86)Sr/(87)Sr in lavas from the central Tonga-Kermadec arc front are consistent with localized input of subducted alkaline Louisville material (lavas and volcaniclastics) into sub-arc partial melts. Furthermore, absolute Pacific Plate motion models indicate an anticlockwise rotation in the subducted Louisville seamount chain that, combined with estimates of the timing of fluid release from the subducting slab, suggests primarily trench-normal mantle flow beneath the central Tonga-Kermadec arc system.

  17. A 9,000-year-old caribou hunting structure beneath Lake Huron.

    Science.gov (United States)

    O'Shea, John M; Lemke, Ashley K; Sonnenburg, Elizabeth P; Reynolds, Robert G; Abbott, Brian D

    2014-05-13

    Some of the most pivotal questions in human history necessitate the investigation of archaeological sites that are now under water. Nine thousand years ago, the Alpena-Amberley Ridge (AAR) beneath modern Lake Huron was a dry land corridor that connected northeast Michigan to southern Ontario. The newly discovered Drop 45 Drive Lane is the most complex hunting structure found to date beneath the Great Lakes. The site and its associated artifacts provide unprecedented insight into the social and seasonal organization of prehistoric caribou hunting. When combined with environmental and simulation studies, it is suggested that distinctly different seasonal strategies were used by early hunters on the AAR, with autumn hunting being carried out by small groups, and spring hunts being conducted by larger groups of cooperating hunters.

  18. NativeView: A Geospatial Curriculum for Native Nation Building

    Science.gov (United States)

    Rattling Leaf, J.

    2007-12-01

    In the spirit of collaboration and reciprocity, James Rattling Leaf of Sinte Gleska University on the Rosebud Reservation of South Dakota will present recent developments, experiences, insights and a vision for education in Indian Country. As a thirty-year young institution, Sinte Gleska University is founded by a strong vision of ancestral leadership and the values of the Lakota Way of Life. Sinte Gleska University (SGU) has initiated the development of a Geospatial Education Curriculum project. NativeView: A Geospatial Curriculum for Native Nation Building is a two-year project that entails a disciplined approach towards the development of a relevant Geospatial academic curriculum. This project is designed to meet the educational and land management needs of the Rosebud Lakota Tribe through the utilization of Geographic Information Systems (GIS), Remote Sensing (RS) and Global Positioning Systems (GPS). In conjunction with the strategy and progress of this academic project, a formal presentation and demonstration of the SGU based Geospatial software RezMapper software will exemplify an innovative example of state of the art information technology. RezMapper is an interactive CD software package focused toward the 21 Lakota communities on the Rosebud Reservation that utilizes an ingenious concept of multimedia mapping and state of the art data compression and presentation. This ongoing development utilizes geographic data, imagery from space, historical aerial photography and cultural features such as historic Lakota documents, language, song, video and historical photographs in a multimedia fashion. As a tangible product, RezMapper will be a project deliverable tool for use in the classroom and to a broad range of learners.

  19. Walking in Balance: Native American Recovery Programmes

    Directory of Open Access Journals (Sweden)

    Suzanne Owen

    2014-10-01

    Full Text Available This article reviews Native American ritual practices, frameworks and key concepts employed by several substance abuse treatments centres in the U.S. and Canada. It also examines the way Alcoholics Anonymous’ Twelve Step programme has been modified to attract and serve the needs of Native Americans and First Nations and its potential impact on the ritual practices. Native concepts of wellbeing are highlighted and linked to the idea of living in “balance”.

  20. Dry Lining as a Method for Maintaining Comfort Levels Beneath Pitched Roofs; An Experimental Case Study

    OpenAIRE

    Hippisley-Cox, Charles

    2010-01-01

    Loft spaces and roof voids present quite a challenge in the refurbishment and conversion of spaces beneath pitched roofs. There is a tendency for expensive heat loss in winter and excessively high temperatures during the summer months. Recent work on a small property in Northern France was used as an opportunity to undertake some tests whilst adopting some modern materials to obtain consistent comfort levels whilst addressing fuel costs and sustainability issues.

  1. Detailed characterization of the anisotropic parameters beneath Iberia and Northern Morocco.

    Science.gov (United States)

    Diaz, Jordi; Gallart, Josep; Morais, Iolanda; Silveira, Graça; Pedreira, David; Pulgar, Javier A.; Dias, Nuno A.; Ruiz, Mario; Gonzalez-Cortina, Juan-Manuel

    2015-04-01

    The knowledge of the anisotropic properties beneath the Iberian Peninsula and Northern Morocco has been dramatically improved since late 2007 with the analysis of the data provided by the dense IberArray broad-band seismic network deployed in the Topo-Iberia project, the increasing number of permanent stations operating in Morocco, Portugal and Spain, and the contribution of smaller scale/higher resolution experiments. The first Topo-Iberia deployment in the Betics-Alboran zone has evidenced a spectacular rotation of the fast polarization direction (FPD) along the Gibraltar arc following the curvature of the Rif-Betic chain. This result has been interpreted as an evidence of mantle flow deflected around the high velocity slab beneath the Alboran Sea Arc. Data from the second Topo-Iberia deployment and from additional deployments in the Moroccan Meseta and the western High Atlas have shown a rather uniform N100°E FPD beneath the Variscan Central Iberian Massif, consistent with global mantle flow models taking into account contributions of surface plate motion, density variations and net lithosphere rotation. The results from the last deployment of the IberArray network presented here cover the northern part of the Iberian Peninsula and also show a rather uniform FPD orientation close to N100°E, confirming the previous interpretation. However, the degree of anisotropy changes significantly, from delay times values around 0.5 s beneath NW Iberia to values reaching 2.0s in its NE corner. The anisotropic parameters retrieved from single events providing high quality data also show significant differences for stations located in the Variscan units of NW Iberia, suggesting that the region includes multiple anisotropic layers or complex anisotropy systems.

  2. Near-shore talik development beneath shallow water in expanding thermokarst lakes, Old Crow Flats, Yukon

    Science.gov (United States)

    Roy-Leveillee, Pascale; Burn, Christopher R.

    2017-05-01

    It is generally assumed that permafrost is preserved beneath shallow lakes and ponds in the Western North American Arctic where water depth is less than about two thirds of the late-winter lake ice thickness. Here we present field observations of talik development beneath water as shallow as 0.2 m despite a lake ice thickness of 1.5 m, in Old Crow Flats (OCF), YT. Conditions leading to the initiation and development of taliks beneath shallow water were investigated with field measurements of shore erosion rates, bathymetry, ice thickness, snow accumulation, and lake bottom temperature near the shores of two expanding lakes in OCF. The sensitivity of talik development to variations in lake bottom thermal regime was then investigated numerically. Where ice reached the lake bottom, talik development was controlled by the ratio of freezing degree days to thawing degree days at the lake bottom (FDDlb/TDDlb). In some cases, spatial variations in on-ice snow depth had a minimal effect on annual mean lake bottom temperature (Tlb) but caused sufficient variations in FDDlb/TDDlb to influence talik development. Where Tlb was close to but greater than 0°C simulations indicated that the thermal offset allowed permafrost aggradation to occur under certain conditions, resulting in irregular near-shore talik geometries. The results highlight the sensitivity of permafrost to small changes in lake bottom thermal conditions where the water column freezes through in early winter and indicate the occurrence of permafrost degradation beneath very shallow water in the near-shore zone of Arctic ponds and lakes.

  3. Three-dimensional structure and seismicity beneath the Central Vanuatu subduction zone

    Science.gov (United States)

    Foix, Oceane; Crawford, Wayne; Pelletier, Bernard; Regnier, Marc; Garaebiti, Esline; Koulakov, Ivan

    2017-04-01

    The 1400-km long Vanuatu subduction zone results from subduction of the oceanic Australian plate (OAP) beneath the North-Fijian microplate (NFM). Seismic and volcanic activity are both high, and several morphologic features enter into subduction, affecting seismicity and probably plate coupling. The Entrecasteaux Ridge, West-Torres plateau, and Bougainville seamount currently enter into subduction below the large forearc islands of Santo and Malekula. This collision coincides with a strongly decreased local convergence velocity rate - 35 mm/yr compared to 120-160 mm/yr to the north and south - and significant uplift on the overriding plate, indicating a high degree of deformation. The close proximity of large uplifted forearc islands to the trench provides excellent coverage of the megathrust seismogenic zone for a seismological study. We used 10 months of seismological data collected using the 30-instrument land and sea ARC-VANUATU seismology network to construct a 3D velocity model — using the LOTOS joint location/model inversion software — and locate 11655 earthquakes using the NonLinLoc software suite. The 3-D model reveals low P and S velocities in the first tens of kilometers beneath both islands, probably due to water infiltration in the heavily faulted upper plate. The model also suggests the presence of a subducted seamount beneath south Santo. The earthquake locations reveal a complex interaction of faults and stress zones related to high and highly variable deformation. Both brittle deformation and the seismogenic zone depth limits vary along-slab and earthquake clusters are identified beneath central and south Santo, at about 10-30 km of depth, and southwest of Malekula island between 10-20 km depth.

  4. Layered Crustal and Mantle Structure and Anisotropy beneath the Afar Depression and Malawi Rift Zone

    Science.gov (United States)

    Reed, Cory Alexander

    Although a wealth of geophysical data sets have been acquired within the vicinity of continental rift zones, the mechanisms responsible for the breakup of stable continental lithosphere are ambiguous. Eastern Africa is host to the largest contemporary rift zone on Earth, and is thus the most prominent site with which to investigate the processes which govern the rupture of continental lithosphere. The studies herein represent teleseismic analyses of the velocity and thermomechanical structure of the crust and mantle beneath the Afar Depression and Malawi Rift Zone (MRZ) of the East African Rift System. Within the Afar Depression, the first densely-spaced receiver function investigation of crustal thickness and inferred velocity attenuation across the Tendaho Graben is conducted, and the largest to-date study of the topography of the mantle transition zone (MTZ) beneath NE Africa is provided, which reveals low upper-mantle velocities beneath the Afar concordant with a probable mantle plume traversing the MTZ beneath the western Ethiopian Plateau. In the vicinity of the MRZ, a data set comprised of 35 seismic stations is employed that was deployed over a two year period from mid-2012 to mid-2014, belonging to the SAFARI (Seismic Arrays For African Rift Initiation) experiment. Accordingly, the first MTZ topography and shear wave splitting analyses were conducted in the region. The latter reveals largely plate motion-parallel anisotropy that is locally modulated by lithospheric thickness abnormalities adjacent to the MRZ, while the former reveals normal MTZ thicknesses and shallow discontinuities that support the presence of a thick lithospheric keel within the MRZ region. These evidences strongly argue for the evolution of the MRZ via passive rifting mechanisms absent lower-mantle influences.

  5. The Baltic Klint beneath the central Baltic Sea and its comparison with the North Estonian Klint

    Science.gov (United States)

    Tuuling, Igor; Flodén, Tom

    2016-06-01

    Along its contact with the Baltic Shield, the margin of the East European Platform reveals a well-developed, flooded terraced relief. The most striking and consistent set of escarpments at the contact of the Lower Palaeozoic calcareous and terrigenous rocks, known as the Baltic Klint (BK), extends from northwest of Russia to the Swedish island of Öland. Marine seismic reflection profiling in 1990-2004 revealed the central Baltic Sea Klint (BSK) section in detail and enabled comparison of its geology/geomorphology with a classical klint-section onshore, namely the North Estonian Klint (NEK). The conception of the BK onshore, which is based on the land-sea separating terraced relief in northern Estonia, is not fully applicable beneath the sea. Therefore, we consider that the BSK includes the entire terraced Cambrian outcrop. We suggest the term "Baltic Klint Complex" to include the well-terraced margin of the Ordovician limestone outcrop, which is weakly developed in Estonia. Because of a steady lithological framework of the bedrock layers across the southern slope of the Fennoscandian Shield, the central BSK in the western and the NEK in the eastern part of the Baltic Homocline have largely identical morphologies. The North Estonian Ordovician limestone plateau with the calcareous crest of the BK extends across the central Baltic Sea, whereas morphological changes/variations along the Klint base occur due to the east-westerly lithostratigraphic/thickness changes in the siliciclastic Cambrian sequence. The verge of the NEK, located some 30-50 m above sea level, starts to drop in altitude as its east-westerly course turns to northeast-southwest in western Estonia. Further westwards, the BK shifts gradually into southerly deepening (0.1-0.2°) layers as its crest drops to c. 150 m below sea level (b.s.l.) near Gotska Sandön. This course change is accompanied by a considerable decrease in thickness of the platform sedimentary cover, as below the central Baltic Sea the

  6. Predicting scour beneath subsea pipelines from existing small free span depths under steady currents

    Directory of Open Access Journals (Sweden)

    Jun Y. Lee

    2017-06-01

    Full Text Available An equation was developed to predict current-induced scour beneath subsea pipelines in areas with small span depths, S. Current equations for scour prediction are only applicable to partially buried pipelines. The existence of small span depths (i.e. S/D < 0.3 are of concern because the capacity for scour is higher at smaller span depths. Furthermore, it is impractical to perform rectification works, such as installing grout bags, under a pipeline with a small S/D. Full-scale two-dimensional computational fluid dynamics (CFD simulations were performed using the Reynolds-averaged Navier–Stokes approach and the Shear stress transport k–ω turbulence model. To predict the occurrence of scour, the computed maximum bed shear stress beneath the pipe was converted to the dimensionless Shields parameter, and compared with the critical Shields parameter based on the mean sediment grain size. The numerical setup was verified, and a good agreement was found between model-scale CFD data and experimental data. Field data were obtained to determine the mean grain size, far field current velocity and to measure the span depths along the surveyed pipe length. A trend line equation was fitted to the full-scale CFD data, whereby the maximum Shields parameter beneath the pipe can be calculated based on the undisturbed Shields parameter and S/D.

  7. Preliminary result of P-wave speed tomography beneath North Sumatera region

    Energy Technology Data Exchange (ETDEWEB)

    Jatnika, Jajat [Earth Science Study Program, Institute of Technology Bandung (Indonesia); Indonesian Meteorological, Climatological and Geophysical Agency (MCGA), Jakarta (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysical Research Group, Faculty of Mining and Petroleum Engineering, Insitute of Technology Bandung (Indonesia); Wandono [Indonesian Meteorological, Climatological and Geophysical Agency (MCGA), Jakarta (Indonesia)

    2015-04-24

    The structure of P-wave speed beneath the North Sumatra region was determined using P-wave arrival times compiled by MCGA from time periods of January 2009 to December 2012 combining with PASSCAL data for February to May 1995. In total, there are 2,246 local earthquake events with 10,666 P-wave phases from 63 stations seismic around the study area. Ray tracing to estimate travel time from source to receiver in this study by applying pseudo-bending method while the damped LSQR method was used for the tomographic inversion. Based on assessment of ray coverage, earthquakes and stations distribution, horizontal grid nodes was set up of 30×30 km2 for inside the study area and 80×80 km2 for outside the study area. The tomographic inversion results show low Vp anomaly beneath Toba caldera complex region and around the Sumatra Fault Zones (SFZ). These features are consistent with previous study. The low Vp anomaly beneath Toba caldera complex are observed around Mt. Pusuk Bukit at depths of 5 km down to 100 km. The interpretation is these anomalies may be associated with ascending hot materials from subduction processes at depths of 80 km down to 100 km. The obtained Vp structure from local tomography will give valuable information to enhance understanding of tectonic and volcanic in this study area.

  8. Constraints on the anisotropic contributions to velocity discontinuities at ∼60 km depth beneath the Pacific

    Science.gov (United States)

    Harmon, Nicholas

    2017-01-01

    Abstract Strong, sharp, negative seismic discontinuities, velocity decreases with depth, are observed beneath the Pacific seafloor at ∼60 km depth. It has been suggested that these are caused by an increase in radial anisotropy with depth, which occurs in global surface wave models. Here we test this hypothesis in two ways. We evaluate whether an increase in surface wave radial anisotropy with depth is robust with synthetic resolution tests. We do this by fitting an example surface wave data set near the East Pacific Rise. We also estimate the apparent isotropic seismic velocity discontinuities that could be caused by changes in radial anisotropy in S‐to‐P and P‐to‐S receiver functions and SS precursors using synthetic seismograms. We test one model where radial anisotropy is caused by olivine alignment and one model where it is caused by compositional layering. The result of our surface wave inversion suggests strong shallow azimuthal anisotropy beneath 0–10 Ma seafloor, which would also have a radial anisotropy signature. An increase in radial anisotropy with depth at 60 km depth is not well‐resolved in surface wave models, and could be artificially observed. Shallow isotropy underlain by strong radial anisotropy could explain moderate apparent velocity drops (depth as suggested by surface waves. Overall, an increase in radial anisotropy with depth may not exist at 60 km beneath the oceans and does not explain the scattered wave observations.

  9. Planetary protection and the search for life beneath the surface of Mars

    Science.gov (United States)

    Mancinelli, Rocco L.

    The search for traces of extinct and extant life on Mars will be extended to beneath the surface of the planet. Current data from Mars missions suggesting the presence of liquid water early in Mars' history and mathematical modeling of the fate of water on Mars imply that liquid water may exist deep beneath the surface of Mars. This leads to the hypothesis that life may exist deep beneath the Martian surface. One possible scenario to look for life on Mars involves a series of unmanned missions culminating with a manned mission drilling deep into the Martian subsurface (/~3Km), collecting samples, and conducting preliminary analyses to select samples for return to earth. This mission must address both forward and back contamination issues, and falls under planetary protection category V. Planetary protection issues to be addressed include provisions stating that the inevitable deposition of earth microbes by humans should be minimized and localized, and that earth microbes and organic material must not contaminate the Martian subsurface. This requires that the drilling equipment be sterilized prior to use. Further, the collection, containment and retrieval of the sample must be conducted such that the crew is protected and that any materials returning to earth are contained (i.e., physically and biologically isolated) and the chain of connection with Mars is broken

  10. Age of the subducting Pacific slab beneath East Asia and its geodynamic implications

    Science.gov (United States)

    Liu, Xin; Zhao, Dapeng; Li, Sanzhong; Wei, Wei

    2017-04-01

    We study the age of the subducting Pacific slab beneath East Asia using a high-resolution model of P-wave tomography and paleo-age data of ancient seafloor. Our results show that the lithosphere age of the subducting slab becomes younger from the Japan Trench (∼130 Ma) to the slab's western edge (∼90 Ma) beneath East China, and the flat (stagnant) slab in the mantle transition zone (MTZ) is the subducted Pacific plate rather than the proposed Izanagi plate which should have already collapsed into the lower mantle. The flat Pacific slab has been in the MTZ for no more than ∼10-20 million years, considerably less than the age of the big mantle wedge beneath East Asia (>110 million years). Hence, the present flat Pacific slab in the MTZ has contributed to the Cenozoic destruction of the East Asian continental lithosphere with extensive intraplate volcanism and back-arc spreading, whereas the destruction of the North China Craton during the Early Cretaceous (∼140-110 Ma) was caused by the subduction of the Izanagi (or the Paleo-Pacific) plate.

  11. Tomography of the upper mantle beneath the African/Iberian collision zone

    Science.gov (United States)

    Bonnin, Mickael; Nolet, Guust; Thomas, Christine; Villaseñor, Antonio; Gallart, Josep; Levander, Alan

    2013-04-01

    In this study we take advantage of the dense broadband-station networks available in western Mediterranean region (IberArray, PICASSO and MOROCCO-MUENSTER networks) to develop a high-resolution 3D tomographic P velocity model of the upper mantle beneath the African/Iberian collision zone. This model is based on teleseismic arrival times recorded between 2008 and 2012 for which cross-correlation delays are measured with a new technique in different frequency bands centered between 0.03 and 1.0 Hz, and interpreted using multiple frequency tomography. Such a tomography is required to scrutinize the nature and extent of the thermal anomalies inferred beneath Northern Africa, especially in the Atlas ranges region and associated to sparse volcanic activities. Tomography is notably needed to help in determining the hypothetical connection between those hot anomalies and the Canary Island hotspot as proposed by geochemistry studies. It also provides new insights on the geometry of the subducting slab previously inferred from tomography, GPS measurements or shear-wave splitting patterns beneath the Alboran Sea and the Betic ranges and is indispensable for deciphering the complex geodynamic history of the Western Mediterranean region. We shall present the overall statistics of the delays, their geographical distribution, as well as the first inversion results.

  12. Analysis of Fracture in Cores from the Tuff Confining Unit beneath Yucca Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Lance Prothro

    2008-03-01

    The role fractures play in the movement of groundwater through zeolitic tuffs that form the tuff confining unit (TCU) beneath Yucca Flat, Nevada Test Site, is poorly known. This is an important uncertainty, because beneath most of Yucca Flat the TCU lies between the sources of radionuclide contaminants produced by historic underground nuclear testing and the regional carbonate aquifer. To gain a better understanding of the role fractures play in the movement of groundwater and radionuclides through the TCU beneath Yucca Flat, a fracture analysis focusing on hydraulic properties was performed on conventional cores from four vertical exploratory holes in Area 7 of Yucca Flat that fully penetrate the TCU. The results of this study indicate that the TCU is poorly fractured. Fracture density for all fractures is 0.27 fractures per vertical meter of core. For open fractures, or those observed to have some aperture, the density is only 0.06 fractures per vertical meter of core. Open fractures are characterized by apertures ranging from 0.1 to 10 millimeter, and averaging 1.1 millimeter. Aperture typically occurs as small isolated openings along the fracture, accounting for only 10 percent of the fracture volume, the rest being completely healed by secondary minerals. Zeolite is the most common secondary mineral occurring in 48 percent of the fractures observed.

  13. Simulation of flow in the unsaturated zone beneath Pagany Wash, Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Thamir, F.; Kwicklis, E.M. [Geological Survey, Denver, CO (United States); Hampson, D. [Foothills Engineering Consultants Inc., Golden, CO (United States); Anderton, S. [ROCKTECH, West Jordan, UT (United States)

    1994-12-31

    A one-dimensional numerical model was created simulate water movement beneath Pagany Wash, Yucca Mountain, Nevada. Model stratigraphy and properties were on data obtained from boreholes UE-25 UZ {number_sign}4 UE-25 UZ {number_sign}5, which were drilled in the alluvial channel and bedrock sideslope of Pagany Wash. Although unable to account for multidimensional or preferential flowpaths beneath the wash, the model proved a useful conceptual tool with which to develop hypotheses and, in some cases, provide bounding calculations. The model indicated that liquid flux decreases with depth in the upper 120 m beneath the wash, with fluxes of several tens mm/yr in the nonwelded base of the Tiva Canyon Member and fluxes on the order of a tenth mm/yr in the upper Topopah Spring Member. Capillary barrier effects were indicated by the model to significantly delay the entry of large fluxes into the potential repository horizon during periods of increasing net infiltration, and to inhibit rapid drainage of water from the nonwelded and bedded intervals into the potential repository horizon during periods of moisture redistribution. Lateral moisture redistribution can be expected to be promoted by these effects.

  14. Crustal thickness and Moho sharpness beneath the Midcontinent rift from receiver functions

    Directory of Open Access Journals (Sweden)

    Moikwathai Moidaki

    2013-02-01

    Full Text Available The Mesoproterozoic Midcontinent rift (MCR in the central US is an approximately 2000 km long, 100 km wide structure from Kansas to Michigan. During the 20-40 million years of rifting, a thick (up to 20 km layer of basaltic lava was deposited in the rift valleys. Quantifying the effects of the rifting and associated volcanic eruptions on the structure and composition of the crust and mantle beneath the MCR is important for the understanding of the evolution of continental lithosphere. In this study we measure the crustal thickness (H, and the sharpness of the Moho (R at about 24 portable and permanent stations in Iowa, Kansas, and South Dakota by stacking Pto- S converted waves (PmS and their multiples (PPmS and PSmS. Under the assumption that the crustal mean velocity in the study area is the same as the IASP91 earth model, we find a significantly thickened crust beneath the MCR of about 53 km. The crustal Vp/Vs ratios increases from about 1.80 off rift to as large as 1.95 within the rift, which corresponds to an increase of Poisson’s ratio from 0.28 to 0.32, suggesting a more mafic crust beneath the MCR. The R measurements are spatially variable and are relatively small in the vicinity of the MCR, indicating the disturbance of the original sharp Moho by the rifting and magmatic intrusion and volcanic eruption.

  15. ( Procambarus clarkii ) (Crustacea: Cambaridae) and native Dytiscid ...

    African Journals Online (AJOL)

    Comparing macrophyte herbivory by introduced Louisiana crayfish ( Procambarus clarkii ) (Crustacea: Cambaridae) and native Dytiscid beetles ( Cybister tripunctatus ) (Coleoptera: Dytiscidae), in Kenya.

  16. Sleep and native language interference affect non-native speech sound learning.

    Science.gov (United States)

    Earle, F Sayako; Myers, Emily B

    2015-12-01

    Adults learning a new language are faced with a significant challenge: non-native speech sounds that are perceptually similar to sounds in one's native language can be very difficult to acquire. Sleep and native language interference, 2 factors that may help to explain this difficulty in acquisition, are addressed in 3 studies. Results of Experiment 1 showed that participants trained on a non-native contrast at night improved in discrimination 24 hr after training, while those trained in the morning showed no such improvement. Experiments 2 and 3 addressed the possibility that incidental exposure to perceptually similar native language speech sounds during the day interfered with maintenance in the morning group. Taken together, results show that the ultimate success of non-native speech sound learning depends not only on the similarity of learned sounds to the native language repertoire, but also to interference from native language sounds before sleep. (c) 2015 APA, all rights reserved).

  17. Contrasting xylem vessel constraints on hydraulic conductivity between native and non-native woody understory species

    Directory of Open Access Journals (Sweden)

    Maria S Smith

    2013-11-01

    Full Text Available We examined the hydraulic properties of 82 native and non-native woody species common to forests of Eastern North America, including several congeneric groups, representing a range of anatomical wood types. We observed smaller conduit diameters with greater frequency in non-native species, corresponding to lower calculated potential vulnerability to cavitation index. Non-native species exhibited higher vessel-grouping in metaxylem compared with native species, however, solitary vessels were more prevalent in secondary xylem. Higher frequency of solitary vessels in secondary xylem was related to a lower potential vulnerability index. We found no relationship between anatomical characteristics of xylem, origin of species and hydraulic conductivity, indicating that non-native species did not exhibit advantageous hydraulic efficiency over native species. Our results confer anatomical advantages for non-native species under the potential for cavitation due to freezing, perhaps permitting extended growing seasons.

  18. 76 FR 3120 - Native American and Alaska Native Children in School Program; Office of English Language...

    Science.gov (United States)

    2011-01-19

    ... Native American and Alaska Native Children in School Program; Office of English Language Acquisition, Language Enhancement, and Academic Achievement for Limited English Proficient Students; Overview... parental and community participation in language instruction educational programs. Projects funded under...

  19. Aerococcus viridans Native Valve Endocarditis

    Directory of Open Access Journals (Sweden)

    Wenwan Zhou

    2013-01-01

    Full Text Available Aerococcus viridans is an infrequent human pathogen and few cases of infective endocarditis have been reported. A case involving a 69-year-old man with colon cancer and hemicolectomy 14 years previously, without recurrence, is reported. A diagnosis of native mitral valve endocarditis was established on the basis of clinical presentation, characteristic echocardiographic findings and pathological specimen examination after urgent valve replacement. A viridans endocarditis appears to be particularly virulent, requiring a surgical approach in four of 10 cases reported and death in one of nine. Given the aggressive nature of A viridans endocarditis and the variable time to diagnosis (a few days to seven months, prompt recognition of symptoms and echocardiography, in addition to blood cultures, should be performed when symptoms persist.

  20. Turkish Students' Perspectives on Speaking Anxiety in Native and Non-Native English Speaker Classes

    Science.gov (United States)

    Bozavli, Ebubekir; Gulmez, Recep

    2012-01-01

    The aim of this study is to reveal the effect of FLA (foreign language anxiety) in native/non-native speaker of English classrooms. In this study, two groups of students (90 in total) of whom 38 were in NS (native speaker) class and 52 in NNS (non-native speaker) class taking English as a second language course for 22 hours a week at Erzincan…

  1. Bent-shaped plumes and horizontal channel flow beneath the 660 km discontinuity

    Science.gov (United States)

    Tosi, Nicola; Yuen, David A.

    2011-12-01

    Recent high-resolution seismic imaging of the transition zone topography beneath the Hawaiian archipelago shows strong evidence for a 1000 to 2000 km wide hot thermal anomaly ponding beneath the 660 km boundary west of Hawaii islands [Q. Cao et al. Seismic imaging of transition zone discontinuities suggests hot mantle west of Hawaii. Science (2011), 332, 1068-1071]. This scenario suggests that Hawaiian volcanism may not be caused by a stationary narrow plume rising from the core-mantle boundary but by hot plume material first held back beneath the 660 km discontinuity and then entrained under the transition zone before coming up to the surface. Using a cylindrical model of iso-chemical mantle convection with multiple phase transitions, we investigate the dynamical conditions for obtaining this peculiar plume morphology. Focusing on the role exerted by pressure-dependent thermodynamic and transport parameters, we show that a strong reduction of the coefficient of thermal expansion in the lower mantle and a viscosity hill at a depth of around 1800 km allow plumes to have enough focused buoyancy to reach and pass the 660 km depth interface. The lateral spreading of plumes near the top of the lower mantle manifests itself as a channel flow whose length is controlled by the viscosity contrast due to temperature variations ∆η T. For small values of ∆η T, broad and highly viscous plumes are generated that tend to pass through the transition zone relatively unperturbed. For higher values (10 2 ≤ ∆η T ≤ 10 3), we obtain horizontal channel flows beneath the 660 km boundary as long as 1500 km within a timescale that resembles that of Hawaiian hotspot activity. This finding could help to explain the origin of the broad hot anomaly observed west of Hawaii. For a normal thermal anomaly of 450 K associated with a lower mantle plume, we obtain activation energies of about 400 kJ/mol and 670 kJ/mol for ∆ ηT = 10 2 and 10 3, respectively, in good agreement with

  2. Saltwater movement in the upper Floridan aquifer beneath Port Royal Sound, South Carolina

    Science.gov (United States)

    Smith, Barry S.

    1994-01-01

    Freshwater for Hilton Head Island, South Carolina, is supplied by withdrawals from the Upper Floridan aquifer. Freshwater for the nearby city of Savannah, Georgia, and for the industry that has grown adjacent to the city, has also been supplied, in part, by withdrawal from the Upper Floridan aquifer since 1885. The withdrawal of ground water has caused water levels in the Upper Floridan aquifer to decline over a broad area, forming a cone of depression in the potentiometric surface of the aquifer centered near Savannah. In 1984, the cone of depression extended beneath Hilton Head Island as far as Port Royal Sound. Flow in the aquifer, which had previously been toward Port Royal Sound, has been reversed, and, as a result, saltwater in the aquifer beneath Port Royal Sound has begun to move toward Hilton Head Island. The Saturated-Unsaturated Transport (SUTRA) model of the U.S. Geological Survey was used for the simulation of density-dependent ground-water flow and solute transport for a vertical section of the Upper Floridan aquifer and upper confining unit beneath Hilton Head Island and Port Royal Sound. The model simulated a dynamic equilibrium between the flow of seawater and freshwater in the aquifer near the Gyben-Herzberg position estimated for the period before withdrawals began in 1885; it simulated reasonable movements of brackish water and saltwater from that position to the position determined by chemical analyses of samples withdrawn from the aquifer in 1984, and it approximated hydraulic heads measured in the aquifer in 1976 and 1984. The solute-transport simulations indicate that the transition zone would continue to move toward Hilton Head Island even if pumping ceased on the island. Increases in existing withdrawals or additional withdrawals on or near Hilton Head Island would accelerate movement of the transition zone toward the island, but reduction in withdrawals or the injection of freshwater would slow movement toward the island, according to the

  3. Radial viscous fingering of hot asthenosphere within the Icelandic plume beneath the North Atlantic Ocean

    Science.gov (United States)

    Schoonman, C. M.; White, N. J.; Pritchard, D.

    2017-06-01

    The Icelandic mantle plume has had a significant influence on the geologic and oceanographic evolution of the North Atlantic Ocean during Cenozoic times. Full-waveform tomographic imaging of this region shows that the planform of this plume has a complex irregular shape with significant shear wave velocity anomalies lying beneath the lithospheric plates at a depth of 100-200 km. The distribution of these anomalies suggests that about five horizontal fingers extend radially beneath the fringing continental margins. The best-imaged fingers lie beneath the British Isles and beneath western Norway where significant departures from crustal isostatic equilibrium have been measured. Here, we propose that these radial fingers are generated by a phenomenon known as the Saffman-Taylor instability. Experimental and theoretical analyses show that fingering occurs when a less viscous fluid is injected into a more viscous fluid. In radial, miscible fingering, the wavelength and number of fingers are controlled by the mobility ratio (i.e. the ratio of viscosities), by the Péclet number (i.e. the ratio of advective and diffusive transport rates), and by the thickness of the horizontal layer into which fluid is injected. We combine shear wave velocity estimates with residual depth measurements around the Atlantic margins to estimate the planform distribution of temperature and viscosity within a horizontal asthenospheric layer beneath the lithospheric plate. Our estimates suggest that the mobility ratio is at least 20-50, that the Péclet number is O (104), and that the asthenospheric channel is 100 ± 20 km thick. The existence and planform of fingering is consistent with experimental observations and with theoretical arguments. A useful rule of thumb is that the wavelength of fingering is 5 ± 1 times the thickness of the horizontal layer. Our proposal has been further tested by examining plumes of different vigor and planform (e.g. Hawaii, Cape Verde, Yellowstone). Our results

  4. Seismic Velocity Structure of the Mantle beneath the Hawaiian Hotspot and Geodynamic Perspectives

    Science.gov (United States)

    Wolfe, C. J.; Laske, G.; Ballmer, M. D.; Ito, G.; Collins, J. A.; Solomon, S. C.; Rychert, C. A.

    2012-12-01

    Data from the PLUME deployments of land and ocean bottom seismometers have provided unprecedented new constraints on regional seismic structure of the mantle beneath the Hawaiian Islands and motivated a new generation of geodynamic models for understanding hotspot origins. Three-dimensional finite-frequency body-wave tomographic images of S- and P-wave velocity structure reveal an upper-mantle low-velocity anomaly beneath Hawaii that is elongated in the direction of the island chain and surrounded by a high-velocity anomaly in the shallow upper mantle that is parabolic in map view. Low velocities continue downward to the mantle transition zone between 410 and 660 km depth and extend into the topmost lower mantle southeast of Hawaii. Upper mantle structure from both S and P waves is asymmetric about the island chain, with lower velocities just southwest of the island of Hawaii and higher velocities to the east. Independent Rayleigh-wave tomography displays a similarly asymmetric structure in the lower lithosphere and asthenosphere, and also reveals a low-velocity anomaly (with horizontal dimensions of 100 by 300 km across and along the chain, respectively) beneath the hotspot swell that reaches to depths of at least 140 km. Shear-wave splitting observations dominantly reflect fossil lithospheric anisotropy, although a signature of asthenospheric flow also may be resolvable. S-to-P receiver function imaging of the lithosphere-asthenosphere boundary suggests shoaling from 100 km west of Hawaii to 80 km beneath the island, a pattern consistent with results from Rayleigh wave imaging. In terms of mantle plume geodynamic models, the broad upper-mantle low-velocity region beneath the Hawaiian Islands may reflect the "diverging pancake" at the top of the upwelling zone; the surrounding region of high velocities could represent a downwelling curtain of relatively cool sublithospheric material; and the low-velocity anomalies southeast of Hawaii in the transition zone and

  5. Assessing the Performance of Automatic Speech Recognition Systems When Used by Native and Non-Native Speakers of Three Major Languages in Dictation Workflows

    DEFF Research Database (Denmark)

    Zapata, Julián; Kirkedal, Andreas Søeborg

    2015-01-01

    In this paper, we report on a two-part experiment aiming to assess and compare the performance of two types of automatic speech recognition (ASR) systems on two different computational platforms when used to augment dictation workflows. The experiment was performed with a sample of speakers...... of three major languages and with different linguistic profiles: non-native English speakers; non-native French speakers; and native Spanish speakers. The main objective of this experiment is to examine ASR performance in translation dictation (TD) and medical dictation (MD) workflows without manual...... transcription vs. with transcription. We discuss the advantages and drawbacks of a particular ASR approach in different computational platforms when used by various speakers of a given language, who may have different accents and levels of proficiency in that language, and who may have different levels...

  6. Relative competence of native and exotic fish hosts for two generalist native trematodes.

    Science.gov (United States)

    Paterson, Rachel A; Lal, Aparna; Dale, Marcia; Townsend, Colin R; Poulin, Robert; Tompkins, Daniel M

    2013-12-01

    Exotic fish species frequently acquire native parasites despite the absence of closely related native hosts. They thus have the potential to affect native counterparts by altering native host-parasite dynamics. In New Zealand, exotic brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss have acquired two native trematodes (Telogaster opisthorchis and Stegodexamene anguillae) from their native definitive host (the longfin eel Anguilla dieffenbachii). We used a combination of field surveys and experimental infections to determine the relative competence of native and exotic fish hosts for these native parasites. Field observations indicated that the longfin eel was the superior host for both parasites, although differences between native and exotic hosts were less apparent for S. anguillae. Experimental infections indicated that both parasites had poorer establishment and survival in salmonids, although some worms matured and attained similar sizes to those in eels before dying. Overall, the field surveys and experimental infections indicate that these exotic salmonids are poor hosts of both native trematodes and their presence may decrease native parasite flow to native hosts.

  7. Germination responses of an invasive species in native and non-native ranges

    Science.gov (United States)

    Jose L. Hierro; Ozkan Eren; Liana Khetsuriani; Alecu Diaconu; Katalin Torok; Daniel Montesinos; Krikor Andonian; David Kikodze; Levan Janoian; Diego Villarreal; Maria Estanga-Mollica; Ragan M. Callaway

    2009-01-01

    Studying germination in the native and non-native range of a species can provide unique insights into processes of range expansion and adaptation; however, traits related to germination have rarely been compared between native and nonnative populations. In a series of common garden experiments, we explored whether differences in the seasonality of precipitation,...

  8. Linking native and invader traits explains native spider population responses to plant invasion

    Science.gov (United States)

    Jennifer N. Smith; Douglas J. Emlen; Dean E. Pearson

    2016-01-01

    Theoretically, the functional traits of native species should determine how natives respond to invader-driven changes. To explore this idea, we simulated a large-scale plant invasion using dead spotted knapweed (Centaurea stoebe) stems to determine if native spiders' web-building behaviors could explain differences in spider population responses to...

  9. Influence of native and non-native multitalker babble on speech recognition in noise

    Directory of Open Access Journals (Sweden)

    Chandni Jain

    2014-03-01

    Full Text Available The aim of the study was to assess speech recognition in noise using multitalker babble of native and non-native language at two different signal to noise ratios. The speech recognition in noise was assessed on 60 participants (18 to 30 years with normal hearing sensitivity, having Malayalam and Kannada as their native language. For this purpose, 6 and 10 multitalker babble were generated in Kannada and Malayalam language. Speech recognition was assessed for native listeners of both the languages in the presence of native and nonnative multitalker babble. Results showed that the speech recognition in noise was significantly higher for 0 dB signal to noise ratio (SNR compared to -3 dB SNR for both the languages. Performance of Kannada Listeners was significantly higher in the presence of native (Kannada babble compared to non-native babble (Malayalam. However, this was not same with the Malayalam listeners wherein they performed equally well with native (Malayalam as well as non-native babble (Kannada. The results of the present study highlight the importance of using native multitalker babble for Kannada listeners in lieu of non-native babble and, considering the importance of each SNR for estimating speech recognition in noise scores. Further research is needed to assess speech recognition in Malayalam listeners in the presence of other non-native backgrounds of various types.

  10. Vowel perception: Effects of non-native language versus non-native dialect

    NARCIS (Netherlands)

    Cutler, A.; Smits, R.; Cooper, N.

    2005-01-01

    Three groups of listeners identified the vowel in CV and VC syllables produced by an American English talker. The listeners were (a) native speakers of American English, (b) native speakers of Australian English (different dialect), and (c) native speakers of Dutch (different language). The

  11. Within-category variance and lexical tone discrimination in native and non-native speakers

    NARCIS (Netherlands)

    Hoffmann, C.W.G.; Sadakata, M.; Chen, A.; Desain, P.W.M.; McQueen, J.M.

    2014-01-01

    In this paper, we show how acoustic variance within lexical tones in disyllabic Mandarin Chinese pseudowords affects discrimination abilities in both native and non-native speakers of Mandarin Chinese. Within-category acoustic variance did not hinder native speakers in discriminating between lexical

  12. Periphyton density is similar on native and non-native plant species

    NARCIS (Netherlands)

    Grutters, B.M.C.; Gross, Elisabeth M.; van Donk, E.; Bakker, E.S.

    2017-01-01

    Non-native plants increasingly dominate the vegetation in aquatic ecosystems and thrive in eutrophic conditions. In eutrophic conditions, submerged plants risk being overgrown by epiphytic algae; however, if non-native plants are less susceptible to periphyton than natives, this would contribute to

  13. Risk to native Uroleucon aphids (Hemiptera: Aphididae) from non-native lady beetles (Coleoptera: Coccinellidae)

    Science.gov (United States)

    Aphids in the genus Uroleucon Mordvilko (Hemiptera: Aphididae) are native herbivores that feed on goldenrod (Solidago spp.) and other Asteraceae in North America. The aphids are potential prey for a wide variety of natural enemies, including native and non-native species of lady beetles (Coleoptera...

  14. Foreign language knowledge can influence native language performance in exclusively native contexts

    NARCIS (Netherlands)

    Hell, A.G. van; Dijkstra, A.F.J.

    2002-01-01

    In three experiments, we studied the influence of foreign language knowledge on native language performance in an exclusively native language context. Trilinguals with Dutch as their native and dominant language (M), English as their second language (L2), and French as their third language (M)

  15. Comparison of native and non-native phone imitation by English and Spanish speakers.

    Science.gov (United States)

    Olmstead, Anne J; Viswanathan, Navin; Aivar, M Pilar; Manuel, Sarath

    2013-01-01

    Experiments investigating phonetic convergence in conversation often focus on interlocutors with similar phonetic inventories. Extending these experiments to those with dissimilar inventories requires understanding the capacity of speakers to imitate native and non-native phones. In the present study, we tested native Spanish and native English speakers to determine whether imitation of non-native tokens differs qualitatively from imitation of native tokens. Participants imitated a [ba]-[pa] continuum that varied in VOT from -60 ms (prevoiced, Spanish [b]) to +60 ms (long lag, English [p]) such that the continuum consisted of some tokens that were native to Spanish speakers and some that were native to English speakers. Analysis of the imitations showed two critical results. First, both groups of speakers demonstrated sensitivity to VOT differences in tokens that fell within their native regions of the VOT continuum (prevoiced region for Spanish and long lag region for English). Secondly, neither group of speakers demonstrated such sensitivity to VOT differences among tokens that fell in their non-native regions of the continuum. These results show that, even in an intentional imitation task, speakers cannot accurately imitate non-native tokens, but are clearly flexible in producing native tokens. Implications of these findings are discussed with reference to the constraints on convergence in interlocutors from different linguistic backgrounds.

  16. Native- and Non-Native Speaking English Teachers in Vietnam: Weighing the Benefits

    Science.gov (United States)

    Walkinshaw, Ian; Duong, Oanh Thi Hoang

    2012-01-01

    This paper examines a common belief that learners of English as a foreign language prefer to learn English from native-speaker teachers rather than non-native speakers of English. 50 Vietnamese learners of English evaluated the importance of native-speakerness compared with seven qualities valued in an English language teacher: teaching…

  17. Perception of facial esthetics by native Chinese participants by using manipulated digital imagery techniques.

    Science.gov (United States)

    Maganzini, A L; Tseng, J Y; Epstein, J Z

    2000-10-01

    This investigation utilized a manipulated digital video imaging model to elicit profile facial esthetics preferences in a lay population of native Chinese participants from Beijing. A series of 4 distinct digitized distortions were constructed from an initial lateral cephalogram. These images represented skeletal or dental changes that differed by 2 standard deviations from the normative values for Chinese adults. Video morphing then created soft-tissue profiles. A series of nonparametric tests validated the digitized distortion model. The native Chinese participants in this sample found that the profile distortions most acceptable were the "flatter", or bimaxillary retrusive distortion, in the male stimulus face and the "anterior divergent", or maxillary deficiency, in the female stimulus face.

  18. 50 CFR 18.23 - Native exemptions.

    Science.gov (United States)

    2010-10-01

    ...) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND... transferred to any person other than an Alaskan Native or delivered, carried, transported, or shipped in interstate or foreign commerce, unless: (i) It is being sent by an Alaskan Native directly or through a...

  19. Stennis Space Center celebrates Native American culture

    Science.gov (United States)

    2009-01-01

    Famie Willis (left), 2009-2010 Choctaw Indian Princess, displays artifacts during Native American Heritage Month activities at Stennis Space Center on Nov. 24. The celebration featured various Native American cultural displays for Stennis employees to view. Shown above are (l to r): Willis, Elaine Couchman of NASA Shared Services Center, John Cecconi of NSSC and Lakeisha Robertson of the Environmental Protection Agency.

  20. The Native Language in Teaching Kindergarten Mathematics

    Science.gov (United States)

    Espada, Janet P.

    2012-01-01

    The use of the native language as a medium of instruction is believed to be the fastest and most natural route towards developing a strong foundation in mathematics literacy (Mimaropa, In D.O.No. 74, s.2009). This study examined the effect of using the native language in the teaching of kindergarten mathematics. A total of 34 five to six year old…

  1. Theoretical Perspectives of How Digital Natives Learn

    Science.gov (United States)

    Kivunja, Charles

    2014-01-01

    Marck Prensky, an authority on teaching and learning especially with the aid of Information and Communication Technologies, has referred to 21st century children born after 1980 as "Digital Natives". This paper reviews literature of leaders in the field to shed some light on theoretical perspectives of how Digital Natives learn and how…

  2. How Digital Native Learners Describe Themselves

    Science.gov (United States)

    Thompson, Penny

    2015-01-01

    Eight university students from the "digital native" generation were interviewed about the connections they saw between technology use and learning, and also their reactions to the popular press claims about their generation. Themes that emerged from the interviews were coded to show patterns in how digital natives describe themselves.…

  3. In Search of Native American Aesthetics

    Science.gov (United States)

    Meyer, Leroy N.

    2001-01-01

    The Native American Church meeting is one contemporary inter-tribal form of the ancient peyote spiritual tradition, represented throughout much of North America. With its deeply integrated elements of artistic expression, the cultural context of the peyote ceremony affords an approach to the major issues of Native American aesthetics. Is some…

  4. Native American Justice Issues in North Dakota.

    Science.gov (United States)

    South Dakota State Advisory Committee to the U.S. Commission on Civil Rights.

    In order to assess the quality of justice available to Native Americans in Burleigh County, North Dakota, investigations were conducted from June 1976 through April 1978 with an informal fact finding meeting as well as interviews with approximately 85 persons in Burleigh County and throughout the state. The 1970 census lists Native Americans…

  5. Gila River Basin Native Fishes Conservation Program

    Science.gov (United States)

    Doug Duncan; Robert W. Clarkson

    2013-01-01

    The Gila River Basin Native Fishes Conservation Program was established to conserve native fishes and manage against nonnative fishes in response to several Endangered Species Act biological opinions between the Bureau of Reclamation and the U.S. Fish and Wildlife Service on Central Arizona Project (CAP) water transfers to the Gila River basin. Populations of some Gila...

  6. Language and Cultural Content in Native Education.

    Science.gov (United States)

    Leavitt, Robert M.

    1991-01-01

    It is possible to provide culturally appropriate education for native Canadian Indian and Inuit children within the framework of the European schooling model by finding a balance between building on the children's native experiences and taking from English language and pedagogy what they can use appropriately in their own culture. (25 references)…

  7. Can We Teach Digital Natives Digital Literacy?

    Science.gov (United States)

    Ng, Wan

    2012-01-01

    In recent years, there has been much debate about the concept of digital natives, in particular the differences between the digital natives' knowledge and adoption of digital technologies in informal versus formal educational contexts. This paper investigates the knowledge about educational technologies of a group of undergraduate students…

  8. Brain Hemispheric Functions and the Native American.

    Science.gov (United States)

    Ross, Allen Chuck

    1982-01-01

    Uses brain research conducted by Dr. Roger Sperry to show that traditional Native Americans are more dominant in right hemisphere thinking, setting them apart from a modern left hemisphere-oriented society (especially emphasized in schools). Describes some characteristics of Native American thinking that illustrate a right hemisphere orientation…

  9. Native American spirituality: a critical reader

    National Research Council Canada - National Science Library

    Irwin, Lee

    2000-01-01

    ...ContentsContents  Native American Spirituality: An Introduction Lee Irwin  :    Mediations of the Spirit: Native American...

  10. Raising native plants in nurseries: basic concepts

    Science.gov (United States)

    R. Kasten Dumroese; Thomas D. Landis; Tara Luna

    2012-01-01

    Growing native plants can be fun, challenging, and rewarding. This booklet, particularly the first chapter that introduces important concepts, is for the novice who wants to start growing native plants as a hobby; however, it can also be helpful to someone with a bit more experience who is wondering about starting a nursery. The second chapter provides basic...

  11. Native American Art and Culture: Documentary Resources.

    Science.gov (United States)

    Lawrence, Deirdre

    1992-01-01

    Presents a brief overview of the evolution of documentary material of Native American cultures and problems confronted by researchers in locating relevant information. Bibliographic sources for research are discussed and a directory of major repositories of Native American art documentation is provided. (EA)

  12. Spatial arrangement overrules environmental factors to structure native and non-native assemblages of synanthropic harvestmen.

    Directory of Open Access Journals (Sweden)

    Christoph Muster

    Full Text Available Understanding how space affects the occurrence of native and non-native species is essential for inferring processes that shape communities. However, studies considering spatial and environmental variables for the entire community - as well as for the native and non-native assemblages in a single study - are scarce for animals. Harvestmen communities in central Europe have undergone drastic turnovers during the past decades, with several newly immigrated species, and thus provide a unique system to study such questions. We studied the wall-dwelling harvestmen communities from 52 human settlements in Luxembourg and found the assemblages to be largely dominated by non-native species (64% of specimens. Community structure was analysed using Moran's eigenvector maps as spatial variables, and landcover variables at different radii (500 m, 1000 m, 2000 m in combination with climatic parameters as environmental variables. A surprisingly high portion of pure spatial variation (15.7% of total variance exceeded the environmental (10.6% and shared (4% components of variation, but we found only minor differences between native and non-native assemblages. This could result from the ecological flexibility of both, native and non-native harvestmen that are not restricted to urban habitats but also inhabit surrounding semi-natural landscapes. Nevertheless, urban landcover variables explained more variation in the non-native community, whereas coverage of semi-natural habitats (forests, rivers at broader radii better explained the native assemblage. This indicates that some urban characteristics apparently facilitate the establishment of non-native species. We found no evidence for competitive replacement of native by invasive species, but a community with novel combination of native and non-native species.

  13. Native and Non-native English Teachers' Perceptions of their Professional Identity: Convergent or Divergent?

    Directory of Open Access Journals (Sweden)

    Zia Tajeddin

    2016-10-01

    Full Text Available There is still a preference for native speaker teachers in the language teaching profession, which is supposed to influence the self-perceptions of native and nonnative teachers. However, the status of English as a globalized language is changing the legitimacy of native/nonnative teacher dichotomy. This study sought to investigate native and nonnative English-speaking teachers’ perceptions about native and nonnative teachers’ status and the advantages and disadvantages of being a native or nonnative teacher. Data were collected by means of a questionnaire and a semi-structured interview. A total of 200 native and nonnative teachers of English from the UK and the US, i.e. the inner circle, and Turkey and Iran, the expanding circle, participated in this study. A significant majority of nonnative teachers believed that native speaker teachers have better speaking proficiency, better pronunciation, and greater self-confidence. The findings also showed nonnative teachers’ lack of self-confidence and awareness of their role and status compared with native-speaker teachers, which could be the result of existing inequities between native and nonnative English-speaking teachers in ELT. The findings also revealed that native teachers disagreed more strongly with the concept of native teachers’ superiority over nonnative teachers. Native teachers argued that nonnative teachers have a good understanding of teaching methodology whereas native teachers are more competent in correct language. It can be concluded that teacher education programs in the expanding-circle countries should include materials for teachers to raise their awareness of their own professional status and role and to remove their misconception about native speaker fallacy.

  14. An Analysis of Student Evaluations of Native and Non Native Korean Foreign Language Teachers

    Directory of Open Access Journals (Sweden)

    Julie Damron

    2009-08-01

    Full Text Available In an effort to analyze the strengths and weaknesses of native and non-native teaching assistants and part-time teachers (both referred to as TAs in this article, students completed 632 evaluations of Ko-rean Language TAs from 2005 to 2008, and these evaluations were compiled for an analysis of variants (ANOVA. The evaluations were categorized into three groups of TAs: native Korean-speaking female, native Korean-speaking male, and non-native male; non-native females would have been included in the study, but there were not enough non-native female teachers to have a reliable sample. In an effort to encourage more self-examined teaching practices, this study addresses the greatest strengths and weaknesses of each group. Results revealed several significant differences between the ratings of the groups: native female TAs rated lowest overall, and non-native male TAs rated highest overall. The most prominent differences be-tween groups occurred in ratings of amount students learned, TAs’ preparedness, TAs’ active involvement in students’ learning, TAs’ enthusiasm, and TAs’ tardiness. This study reviews students’ written comments on the evaluations and proposes possible causes of these findings, concluding that differences in ratings are based on both teaching patterns associated with each group of TAs and student re-sponse bias that favors non-native male speakers. Teaching patterns include a tendency for native (Korean female TAs to teach using a lecture format and non-native male TAs to teach using a discussion format; for native TAs to have difficulty adapting to the language level of the students; and for a more visible enthusiasm for Korean culture held by non-native TAs. Causes for bias may include “other-ing” females and natives, TA selection procedures, and trends in evaluating TAs based on language level.

  15. Preliminary assessment of a previously unknown fault zone beneath the Daytona Beach sand blow cluster near Marianna, Arkansas

    Science.gov (United States)

    Odum, Jackson K.; Williams, Robert; Stephenson, William J.; Tuttle, Martitia P.; Al-Shukri, Hadar

    2016-01-01

    We collected new high‐resolution P‐wave seismic‐reflection data to explore for possible faults beneath a roughly linear cluster of early to mid‐Holocene earthquake‐induced sand blows to the south of Marianna, Arkansas. The Daytona Beach sand blow deposits are located in east‐central Arkansas about 75 km southwest of Memphis, Tennessee, and about 80 km south of the southwestern end of the New Madrid seismic zone (NMSZ). Previous studies of these sand blows indicate that they were produced between 10,500 and 5350 yr B.P. (before A.D. 1950). The sand blows are large and similar in size to those in the heart of the NMSZ produced by the 1811–1812 earthquakes. The seismic‐reflection profiles reveal a previously unknown zone of near‐vertical faults imaged in the 100–1100‐m depth range that are approximately coincident with a cluster of earthquake‐induced sand blows and a near‐linear surface lineament composed of air photo tonal anomalies. These interpreted faults are expressed as vertical discontinuities with the largest displacement fault showing about 40 m of west‐side‐up displacement at the top of the Paleozoic section at about 1100 m depth. There are about 20 m of folding on reflections within the Eocene strata at 400 m depth. Increasing fault displacement with depth suggests long‐term recurrent faulting. The imaged faults within the vicinity of the numerous sand blow features could be a causative earthquake source, although it does not rule out the possibility of other seismic sources nearby. These newly located faults add to a growing list of potentially active Pleistocene–Holocene faults discovered over the last two decades that are within the Mississippi embayment region but outside of the historical NMSZ.

  16. The new digital natives cutting the chord

    CERN Document Server

    Dingli, Alexei

    2015-01-01

    The first generation of Digital Natives (DNs) is now growing up.  However, these digital natives were rather late starters since; their exposure to computers started when they could master the mouse and the penetration of computers in educational institutions was still very low. Today, a new breed of digital natives is emerging.  This new breed includes those individuals who are being introduced from their first instances to the world of wireless devices. One year olds manage to master the intuitive touch interfaces of their tablets whilst sitting comfortably in their baby bouncers. The controller-less interfaces allow these children to interact with a machine in a way which was unconceivable below. Thus, our research investigated the paradigm shift between the different generations of digital natives. We analysed the way in which these two generations differ from each other and we explored how the world needs to change in order to harness the potential of these new digital natives.

  17. Non-native plants and wildlife in the Intermountain West

    Science.gov (United States)

    Andrea R. Litt; Dean E. Pearson

    2013-01-01

    Non-native plant invasions can change communities and ecosystems by altering the structure and composition of native vegetation. Changes in native plant communities caused by non-native plants can influence native wildlife species in diverse ways, but the outcomes and underlying mechanisms are poorly understood. Here, we review and synthesize current information for...

  18. Native Teen Voices: adolescent pregnancy prevention recommendations.

    Science.gov (United States)

    Garwick, Ann W; Rhodes, Kristine L; Peterson-Hickey, Melanie; Hellerstedt, Wendy L

    2008-01-01

    American Indian adolescent pregnancy rates are high, yet little is known about how Native youth view primary pregnancy prevention. The aim was to identify pregnancy prevention strategies from the perspectives of both male and female urban Native youth to inform program development. Native Teen Voices (NTV) was a community-based participatory action research study in Minneapolis and St. Paul, Minnesota. Twenty focus groups were held with 148 Native youth who had never been involved in a pregnancy. Groups were stratified by age (13-15 and 16-18 years) and sex. Participants were asked what they would do to prevent adolescent pregnancy if they were in charge of programs for Native youth. Content analyses were used to identify and categorize the range and types of participants' recommendations within and across the age and sex cohorts. Participants in all cohorts emphasized the following themes: show the consequences of adolescent pregnancy; enhance and develop more pregnancy prevention programs for Native youth in schools and community-based organizations; improve access to contraceptives; discuss teen pregnancy with Native youth; and use key messages and media to reach Native youth. Native youth perceived limited access to comprehensive pregnancy prevention education, community-based programs and contraceptives. They suggested a variety of venues and mechanisms to address gaps in sexual health services and emphasized enhancing school-based resources and involving knowledgeable Native peers and elders in school and community-based adolescent pregnancy prevention initiatives. A few recommendations varied by age and sex, consistent with differences in cognitive and emotional development.

  19. Chinese College Students’ Views on Native English and Non-native English in EFL Classrooms

    Directory of Open Access Journals (Sweden)

    Yang Qian

    2016-08-01

    Full Text Available With the development of globalization, English is clearly spoken by many more non-native than native speakers, which raises the discussion of English varieties and the debate regarding the conformity to Standard English. Although a large number of studies have shown scholars’ attitudes towards native English and non-native English, little research is conducted from the point of college students until recently. This paper focuses on Chinese college students’ perceptions of native English and non-native English in order to offer insights into the mainstream English language teaching in terms of its exclusive reference to English as a native language in China. This paper draws on the data contributed by 50 Chinese university students through questionnaires. The questionnaire responses displayed a superficial preference for native English and a potential inclination for non-native English in EFL classrooms. The article argues that factors behind the attitude point to the need of changing mainstream English teaching. Keywords: Native English, Non-native English, Chinese college students’ attitudes, mainstream English teaching

  20. Review of the negative influences of non-native salmonids on native fish species

    Science.gov (United States)

    Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.

    2013-01-01

    Non-native salmonids are often introduced into areas containing species of concern, yet a comprehensive overview of the short- and long-term consequences of these introductions is lacking in the Great Plains. Several authors have suggested that non-native salmonids negatively inflfluence species of concern. The objective of this paper is to review known interactions between non-native salmonids and native fifishes, with a focus on native species of concern. After an extensive search of the literature, it appears that in many cases non-native salmonids do negatively inflfl uence species of concern (e.g., reduce abundance and alter behavior) via different mechanisms (e.g., predation and competition). However, there are some instances in which introduced salmonids have had no perceived negative inflfl uence on native fifi shes. Unfortunately, the majority of the literature is circumstantial, and there is a need to experimentally manipulate these interactions.

  1. Biophysical Profile

    Science.gov (United States)

    ... and pregnancy High-risk pregnancy Biophysical profile About Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  2. Profiling cancer

    DEFF Research Database (Denmark)

    Ciro, Marco; Bracken, Adrian P; Helin, Kristian

    2003-01-01

    In the past couple of years, several very exciting studies have demonstrated the enormous power of gene-expression profiling for cancer classification and prediction of patient survival. In addition to promising a more accurate classification of cancer and therefore better treatment of patients......, gene-expression profiling can result in the identification of novel potential targets for cancer therapy and a better understanding of the molecular mechanisms leading to cancer....

  3. Layered anisotropy within the crust and lithospheric mantle beneath the Sea of Japan

    Science.gov (United States)

    Legendre, C. P.; Zhao, L.; Deschamps, F.; Chen, Q.-F.

    2016-10-01

    Continental rifting during the Oligocene to mid-Miocene caused the opening of the Sea of Japan and the separation between the Japanese Islands and the Eurasian Plate. The tectonic evolution in the Sea of Japan is important for understanding the evolution of back-arc regions in active convergent margins. Here, we use data from the seismic stations surrounding the Sea of Japan to map the Rayleigh-wave azimuthal anisotropy in the crust and lithospheric mantle beneath the Sea of Japan. We explore the variations of Rayleigh-wave phase-velocity beneath the Sea of Japan in a broad period range (30-80 s). Rayleigh-wave dispersion curves are measured by the two-station technique for a total of 231 interstation paths using vertical-component broad-band waveforms at 22 seismic stations around the Sea of Japan from 1411 global earthquakes. The resulting maps of Rayleigh-wave phase velocity and azimuthal anisotropy allow the examination of azimuthal anisotropy at specific periods. They exhibit several regions with different isotropic and anisotropic patterns: the Japan Basin displays fast velocities at shorter periods (30 and 40 s) with NNE-SSW anisotropy, whereas at 60 s and longer, the velocities become slow even if the anisotropy remains NE-SW; the East China Sea shows fast velocities at all periods (30-80 s) with constant NW-SE anisotropy. Trench-normal anisotropy beneath the Japanese Islands is found at short periods (30-40 s) and become trench-parallel at periods of 60 s and longer. Overall, our model resolves two layers of anisotropy, the shallowest and deepest layers being potentially related to frozen deformation due to recent geodynamic events, and asthenospheric flow, respectively.

  4. Crustal structure beneath Beijing and its surrounding regions derived from gravity data

    Science.gov (United States)

    Jiang, Wenliang; Zhang, Jingfa; Lu, Xiaocui; Lu, Jing

    2011-06-01

    In this paper we use gravity data to study fine crustal structure and seismogenic environment beneath Beijing and its surrounding regions. Multi-scale wavelet analysis method is applied to separating gravity fields. Logarithmic power spectrum method is also used to calculate depth of gravity field source. The results show that the crustal structure is very complicated beneath Beijing and its surrounding areas. The crustal density exhibits laterally inhomogeneous. There are three large scale tectonic zones in North China, i.e., WNW-striking Zhangjiakou-Bohai tectonic zone (ZBTZ), NE-striking Taihang piedmont tectonic zone (TPTZ) and Cangxian tectonic zone (CTZ). ZBTZ and TPTZ intersect with each other beneath Beijing area and both of them cut through the lithosphere. The upper and middle crusts consist of many small-scale faults, uplifts and depressions. In the lower crust, these small-scale tectonic units disappear gradually, and they are replaced by large-scale tectonic units. In surrounding regions of Beijing, ZBTZ intersects with several other NE-striking tectonic units, such as Cangxian uplift, Jizhong depression and Shanxi Graben System (SGS). In west of Taihangshan uplift, gravity anomalies in upper and middle crusts are correlated with geological and topographic features on the surface. Compared with the crust, the structure is comparatively simple in uppermost mantle. Earthquakes mainly occurred in upper and middle crusts, especially in transitional regions between high gravity anomaly and low gravity anomaly. Occurrence of large earthquakes may be related to the upwelling of upper mantle and asthenosphere heat flow materials, such as Sanhe earthquake ( M S8.0) and Tangshan earthquake ( M S7.8).

  5. Nature and extent of lava-flow aquifers beneath Pahute Mesa, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Prothro, L.B.; Drellack, S.L. Jr.

    1997-09-01

    Work is currently underway within the Underground Test Area subproject of the US Department of Energy/Nevada Operations Office Environmental Restoration Program to develop corrective action plans in support of the overall corrective action strategy for the Nevada Test Site as established in the Federal Facility Agreement and Consent Order (FFACO, 1996). A closure plan is currently being developed for Pahute Mesa, which has been identified in the FFACO as consisting of the Western and Central Pahute Mesa Corrective Action Units. Part of this effort requires that hydrogeologic data be compiled for inclusion in a regional model that will be used to predict a contaminant boundary for these Corrective Action Units. Hydrogeologic maps have been prepared for use in the model to define the nature and extent of aquifers and confining units that might influence the flow of contaminated groundwater from underground nuclear tests conducted at Pahute Mesa. Much of the groundwater flow beneath Pahute Mesa occurs within lava-flow aquifers. An understanding of the distribution and hydraulic character of these important hydrogeologic units is necessary to accurately model groundwater flow beneath Pahute Mesa. This report summarizes the results of a study by Bechtel Nevada geologists to better define the hydrogeology of lava-flow aquifers at Pahute Mesa. The purpose of this study was twofold: (1) aid in the development of the hydrostratigraphic framework for Pahute Mesa, and (2) provide information on the distribution and hydraulic character of lava-flow aquifers beneath Pahute Mesa for more accurate computer modeling of the Western and Central Pahute Mesa Corrective Action Units.

  6. Constraints on the anisotropic contributions to velocity discontinuities at ∼60 km depth beneath the Pacific.

    Science.gov (United States)

    Rychert, Catherine A; Harmon, Nicholas

    2017-08-01

    Strong, sharp, negative seismic discontinuities, velocity decreases with depth, are observed beneath the Pacific seafloor at ∼60 km depth. It has been suggested that these are caused by an increase in radial anisotropy with depth, which occurs in global surface wave models. Here we test this hypothesis in two ways. We evaluate whether an increase in surface wave radial anisotropy with depth is robust with synthetic resolution tests. We do this by fitting an example surface wave data set near the East Pacific Rise. We also estimate the apparent isotropic seismic velocity discontinuities that could be caused by changes in radial anisotropy in S-to-P and P-to-S receiver functions and SS precursors using synthetic seismograms. We test one model where radial anisotropy is caused by olivine alignment and one model where it is caused by compositional layering. The result of our surface wave inversion suggests strong shallow azimuthal anisotropy beneath 0-10 Ma seafloor, which would also have a radial anisotropy signature. An increase in radial anisotropy with depth at 60 km depth is not well-resolved in surface wave models, and could be artificially observed. Shallow isotropy underlain by strong radial anisotropy could explain moderate apparent velocity drops (<6%) in SS precursor imaging, but not receiver functions. The effect is diminished if strong anisotropy also exists at 0-60 km depth as suggested by surface waves. Overall, an increase in radial anisotropy with depth may not exist at 60 km beneath the oceans and does not explain the scattered wave observations.

  7. A journey to the seismic low velocity zone beneath the ocean (Beno Gutenberg Medal Lecture)

    Science.gov (United States)

    Kawakatsu, Hitoshi

    2017-04-01

    The seismic low velocity zone (LVZ), first proposed by Beno Gutenberg, is an enigmatic layer of the Earth that has been drawing attention of earth scientists, most-likely because of its close association with the asthenosphere that enables plate motions in the plate tectonics context. "A journey to the LVZ", therefore, is equivalent to a journey to elucidate the lithosphere-asthenosphere system (LAS) beneath the ocean (at least that is what I mean by this title). Plate tectonics started as a theory of ocean basins nearly 50 years ago, but the mechanical details of how it works are still highly debated. It has been hampered partly by our inability to characterize the physical properties of the LAS beneath the ocean. I will discuss existing observational constraints, including our own results, on the physical properties of the LAS for normal oceanic regions, where plate tectonics is expected to present its simplest form. While a growing number of seismic data on land have provided remarkable advances in large scale pictures, seafloor observations have been shedding new light on the essential details. Particularly, recent advances in ocean bottom broadband seismometry, together with advances in the seismic analysis methodology, have now enabled us to resolve the regional 1-D structure of the entire LAS, from the surface to a depth of 200km, including seismic anisotropy (azimuthal), with deployments of 15 broadband ocean bottom seismometers for 1 2 years. We have thus succeeded to model the entire oceanic LAS without a priori assumption for the shallow-most structure, the assumption often made for the global surface wave tomography. I hope to convince the audience that we are now at an exciting stage that a large-scale array experiment in the ocean (e.g., Pacific Array: http://eri-ndc.eri.u-tokyo.ac.jp/PacificArray/) is becoming approachable to elucidate the enigma of the LVZ, thus the lithosphere-asthenosphere system, beneath the ocean.

  8. Lithospheric and sublithospheric anisotropy beneath the Baltic shield from surface-wave array analysis

    Science.gov (United States)

    Pedersen, Helle A.; Bruneton, Marianne; Maupin, Valérie; Svekalapko Seismic Tomography Working Group

    2006-04-01

    We report measurements of radial and azimuthal anisotropy in the upper mantle beneath southern and central Finland, which we obtained by array analysis of fundamental-mode Rayleigh and Love waves. Azimuthally averaged phase velocities were analysed in the period range 15 to 190 s for Rayleigh waves and 15 to 100 s for Love waves. The azimuthal variation of the Rayleigh wave phase velocities was obtained in the period range 20 to 100 s. The limited depth resolution of fundamental-mode surface waves necessitated strong damping constraints in the inversion for anisotropic parameters. We investigated the effects of non-unicity on the final model by experimenting with varying model geometries. The radial anisotropy beneath Finland can be explained by a lithosphere at least 200 km thick, predominantly (> 50% by volume) composed of olivine crystals having their a-axes randomly distributed in the horizontal plane. On the contrary, the measured lithospheric azimuthal anisotropy is small. This can be reconciled with body-wave observations made in the area that indicate a complex pattern of rapidly varying anisotropy. Below 200-250 km depth, that is below the petrologic lithosphere as revealed by xenolith analyses conducted in the area, the magnitude of the azimuthal anisotropy increases and would be compatible with a mantle containing 15-20% by volume of olivine crystals whose a-axes are coherently aligned in the N-NE direction. The alignment of the a-axes is off the direction of present-day absolute plate motion in either the no-net-rotation or hot-spot reference frame, currently N55-N60. We interpret this mismatch as evidence for a complex convective flow pattern of the mantle beneath the shield, which, by inference, is decoupled from the overlying lithosphere.

  9. Potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets

    Science.gov (United States)

    Livingstone, S. J.; Clark, C. D.; Woodward, J.; Kingslake, J.

    2013-11-01

    We use the Shreve hydraulic potential equation as a simplified approach to investigate potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets. We validate the method by demonstrating its ability to recall the locations of >60% of the known subglacial lakes beneath the Antarctic Ice Sheet. This is despite uncertainty in the ice-sheet bed elevation and our simplified modelling approach. However, we predict many more lakes than are observed. Hence we suggest that thousands of subglacial lakes remain to be found. Applying our technique to the Greenland Ice Sheet, where very few subglacial lakes have so far been observed, recalls 1607 potential lake locations, covering 1.2% of the bed. Our results will therefore provide suitable targets for geophysical surveys aimed at identifying lakes beneath Greenland. We also apply the technique to modelled past ice-sheet configurations and find that during deglaciation both ice sheets likely had more subglacial lakes at their beds. These lakes, inherited from past ice-sheet configurations, would not form under current surface conditions, but are able to persist, suggesting a retreating ice-sheet will have many more subglacial lakes than advancing ones. We also investigate subglacial drainage pathways of the present-day and former Greenland and Antarctic ice sheets. Key sectors of the ice sheets, such as the Siple Coast (Antarctica) and NE Greenland Ice Stream system, are suggested to have been susceptible to subglacial drainage switching. We discuss how our results impact our understanding of meltwater drainage, basal lubrication and ice-stream formation.

  10. A Simple Diagnostic Model of the Circulation Beneath an Ice Shelf

    Science.gov (United States)

    Jenkins, Adrian; Nøst, Ole Anders

    2017-04-01

    The ocean circulation beneath ice shelves supplies the heat required to melt ice and exports the resulting freshwater. It therefore plays a key role in determining the mass balance and geometry of the ice shelves and hence the restraint they impose on the outflow of grounded ice from the interior of the ice sheet. Despite this critical role in regulating the ice sheet's contribution to eustatic sea level, an understanding of some of the most basic features of the circulation is lacking. The conventional paradigm is one of a buoyancy-forced overturning circulation, with inflow of warm, salty water along the seabed and outflow of cooled and freshened waters along the ice base. However, most sub-ice-shelf cavities are broad relative to the internal Rossby radius, so a horizontal circulation accompanies the overturning. Primitive equation ocean models applied to idealised geometries produce cyclonic gyres of comparable magnitude, but in the absence of a theoretical understanding of what controls the gyre strength, those solutions can only be validated against each other. Furthermore, we have no understanding of how the gyre circulation should change given more complex geometries. To begin to address this gap in our theoretical understanding we present a simple, linear, steady-state model for the circulation beneath an ice shelf. Our approach in analogous to that of Stommel's classic analysis of the wind-driven gyres, but is complicated by the fact that his most basic assumption of homogeneity is inappropriate. The only forcing on the flow beneath an ice shelf arises because of the horizontal density gradients set up by melting. We thus arrive at a diagnostic model which gives us the depth-dependent horizontal circulation that results from an imposed geometry and density distribution. We describe the development of the model and present some preliminary solutions for the simplest cavity geometries.

  11. Receiver function imaging of upper mantle complexity beneath the Pacific Northwest, United States

    Science.gov (United States)

    Eagar, Kevin C.; Fouch, Matthew J.; James, David E.

    2010-08-01

    Small-scale topographic variations on the upper mantle seismic discontinuities provide important constraints on the thermal influences of upwellings and downwellings in geodynamically complex regions. Subduction of the Juan de Fuca plate and other tectonic processes dominating the Pacific Northwest, United States in the Cenozoic involve massive thermal flux that likely result in an upper mantle that has strong 3-D temperature variations. We address the interaction of such processes in the region using receiver functions to image the upper mantle seismic discontinuities at 410 and 660 km. We utilized over 15 000 high quality receiver functions gathered from 294 teleseismic earthquakes recorded at 277 regional broadband seismic stations, primarily those of the Earthscope/USArray Transportable Array. We find the average depths of the discontinuities to be 412 km and 658 km, respectively, with no obvious 520 km discontinuity detected. The peak-to-peak range is greater on the '410' than the '660', suggesting the possibility of more significant regional dynamic processes at upper mantle depths. Our results are not consistent with a mantle plume below central Oregon in the High Lava Plains region. Our observation of a thinner transition zone beneath the western Snake River Plain region, however, is consistent with a regional increase in mantle temperatures, perhaps due to either asthenospheric flow from beneath and around the southern edge of the Juan de Fuca plate, or to vertical flow in the form of regional mantle upwelling related to the Snake River Plain / Yellowstone hotspot track. Further, our results are not consistent with a simple subducting Juan de Fuca slab morphology, but rather suggest similar levels of significant complexity in slab structure found by recent regional tomographic studies. We find evidence for a thickened and therefore cooler mantle transition zone beneath the Wallowa / Idaho Batholith region, consistent with tomographic models which suggest

  12. Chronic Liver Disease and American Indians/Alaska Natives

    Science.gov (United States)

    ... American Indian/Alaska Native > Chronic Liver Disease Chronic Liver Disease and American Indians/Alaska Natives Among American Indians and Alaska Natives, chronic liver disease is a leading cause of death. While the ...

  13. Engaging Digital Natives through Social Learning

    Directory of Open Access Journals (Sweden)

    Nina Sarkar

    2017-04-01

    Full Text Available Digital natives account for a substantial portion of the total enrollment in higher education. This calls for significant educational reforms because traditional education systems do not cater to the needs and interests of digital natives. The most effective way that both students and instructors can benefit from this paradigm shift is to integrate technology that is appropriate to the cognitive learning patterns of the digital natives into the curriculum. This paper builds upon previous research in technology/personality theory and specifically attempts to provide examples of technology that will address the instructional needs of digital natives. Further this paper provides empirical evidence of the impact of technology integration on the learning outcomes of digital natives. In this study, the authors explored the impact of targeted technology on academic performance in three businesses courses. Three functional technologies were used by the authors to build engaging course content, efficiently manage course content, and to interact with digital native students. This study found that these technologies can assist digital natives in the learning process and lead to better academic performance.

  14. Technology Solutions Case Study: Capillary Break Beneath a Slab: Polyethylene Sheeting over Aggregate, Southwestern Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-07-01

    In this project, Building America team IBACOS worked with a builder of single- and multifamily homes in southwestern Pennsylvania (climate zone 5) to understand its methods of successfully using polyethylene sheeting over aggregate as a capillary break beneath the slab in new construction. This builder’s homes vary in terms of whether they have crawlspaces or basements. However, in both cases, the strategy protects the home from water intrusion via capillary action (e.g., water wicking into cracks and spaces in the slab), thereby helping to preserve the durability of the home.

  15. Lithospheric structure beneath the Northwest Iran using Ps and Sp converted waves

    OpenAIRE

    F. T. Farahmand; Forough Sodoudi

    2009-01-01

    We compute P and S receiver functions to investigate the crustal and lithospheric thickness as well as the Vp/Vs ratio beneath the Northwest of Iran and map out the lateral variations of these discontinuities under this region.We selected data from teleseismic events (Mb ≥ 5.5, epicentral distance between 30°-95° for P receiver functions and Mb > 5.7, epicentral distance between 60°-85° for S receiver functions) recorded since 1995 to present at 8 three component short period stations from Ta...

  16. Large-scale trench-normal mantle flow beneath central South America

    Science.gov (United States)

    Reiss, M. C.; Rümpker, G.; Wölbern, I.

    2018-01-01

    We investigate the anisotropic properties of the fore-arc region of the central Andean margin between 17-25°S by analyzing shear-wave splitting from teleseismic and local earthquakes from the Nazca slab. With partly over ten years of recording time, the data set is uniquely suited to address the long-standing debate about the mantle flow field at the South American margin and in particular whether the flow field beneath the slab is parallel or perpendicular to the trench. Our measurements suggest two anisotropic layers located within the crust and mantle beneath the stations, respectively. The teleseismic measurements show a moderate change of fast polarizations from North to South along the trench ranging from parallel to subparallel to the absolute plate motion and, are oriented mostly perpendicular to the trench. Shear-wave splitting measurements from local earthquakes show fast polarizations roughly aligned trench-parallel but exhibit short-scale variations which are indicative of a relatively shallow origin. Comparisons between fast polarization directions from local earthquakes and the strike of the local fault systems yield a good agreement. To infer the parameters of the lower anisotropic layer we employ an inversion of the teleseismic waveforms based on two-layer models, where the anisotropy of the upper (crustal) layer is constrained by the results from the local splitting. The waveform inversion yields a mantle layer that is best characterized by a fast axis parallel to the absolute plate motion which is more-or-less perpendicular to the trench. This orientation is likely caused by a combination of the fossil crystallographic preferred orientation of olivine within the slab and entrained mantle flow beneath the slab. The anisotropy within the crust of the overriding continental plate is explained by the shape-preferred orientation of micro-cracks in relation to local fault zones which are oriented parallel to the overall strike of the Andean range. Our

  17. Deep groundwater and potential subsurface habitats beneath an Antarctic dry valley

    DEFF Research Database (Denmark)

    Mikucki, J. A.; Auken, E.; Tulaczyk, S.

    2015-01-01

    The occurrence of groundwater in Antarctica, particularly in the ice-free regions and along the coastal margins is poorly understood. Here we use an airborne transient electromagnetic (AEM) sensor to produce extensive imagery of resistivity beneath Taylor Valley. Regional-scale zones of low...... subsurface resistivity were detected that are inconsistent with the high resistivity of glacier ice or dry permafrost in this region. We interpret these results as an indication that liquid, with sufficiently high solute content, exists at temperatures well below freezing and considered within the range...

  18. Small subsidence of the 660-km discontinuity beneath Japan probed by ScS reverberations

    Science.gov (United States)

    Kato, Mamoru; Misawa, Mika; Kawakatsu, Hitoshi

    We investigate layering structure in the mantle beneath Japan using ScS reverberation waveforms of two recent large deep events in the northwest Pacific. We estimate regional variation of the elastic and anelastic structure of the mantle as well as properties of the major velocity discontinuities by modeling broadband seismograms recorded at two dense networks, J-Array and FREESIA. The 660-km discontinuity is the deepest in the region where the stagnant subducting slab in the transition zone is tomographically imaged, but the subsidence is of ∼10 km, much smaller than previous estimates with SS precursors. No significant elevation is detected for the 410-km discontinuity.

  19. Geometry of the Main Himalayan Thrust and Moho beneath Satluj valley, northwest Himalaya: Constraints from receiver function analysis

    Science.gov (United States)

    Hazarika, Devajit; Wadhawan, Monika; Paul, Arpita; Kumar, Naresh; Borah, Kajaljyoti

    2017-04-01

    Crustal configuration beneath the Satluj valley region of the northwest Himalaya has been studied with the help of receiver function analysis of teleseismic earthquakes recorded by 18 broadband seismological stations. These stations were located on diverse geotectonic units from the Himalayan foreland basin in the south to the Tethyan Himalaya (TH) in the north. A gentle north dipping structure of the Main Himalayan Thrust (MHT) is imaged between the Sub and Higher Himalaya in contrast to the reported ramp structure of the MHT beneath the Garhwal and Nepal Himalaya. The ramp structure is, however, identified further north, beyond the South Tibetan Detachment in Satluj valley. The depth of the MHT varies from 16 to 27 km across the Sub, Lesser, and Higher Himalaya, and it increases to 38 km beneath the TH forming a ramp. This is significantly a different structure of the MHT beneath the Satluj valley, which is attributed to the effect of underthrusting Delhi-Hardwar Ridge, a transverse structure to the Himalayan arc. Conspicuously, no strong or large earthquake is observed during 1964-2015 in this segment of the Himalayan Seismic Belt. The RF modeling, on the other hand, shows 44 km crustal thickness beneath the Himalayan Frontal Thrust (HFT), and it gradually increases to 62 km beneath the TH. Low shear wave velocity ( 0.8-1.8 km s-1) is observed in the uppermost 3-4 km of the crust beneath the stations near the HFT, which may be the effect of the sedimentary column of the Indo-Gangetic Plain.

  20. Mantle Flow and Melting Beneath Young Oceanic Lithosphere: Seismic Studies of the Galapagos Archipelago and the Juan de Fuca Plate

    Science.gov (United States)

    Byrnes, Joseph Stephen

    In this dissertation, I use seismic imaging techniques to constrain the physical state of the upper mantle beneath regions of young oceanic lithosphere. Mantle convection is investigated beneath the Galapagos Archipelago and then beneath the Juan de Fuca (JdF) plate, with a focus on the JdF and Gorda Ridges before turning to the off-axis asthenosphere. In the Galapagos Archipelago, S-to-p receiver functions reveal a discontinuity in seismic velocity that is attributed to the dehydration of the upper mantle. The depth at which dehydration occurs is shown to be consistent with prior constraints on mantle temperature. A comparison between results from receiver functions, seismic tomography and petrology shows that mantle upwelling and melt generation occur shallower than the depth of the discontinuity, despite the expectation of high viscosities in the dehydrated layer. Beneath the JdF and Gorda Ridge, low Vs anomalies are too large to be explained by the cooling of the lithosphere and are attributed to partial melt. The asymmetry, large Vs gradients, and sinuosity of the anomalies beneath the JdF Ridge are consistent with models of buoyancy-driven upwelling. However, deformation zone processes appear to dominate mantle flow over seafloor spreading beneath the Explorer and Gorda diffuse plate boundaries. Finally, S-to-p receiver functions reveal a seismic discontinuity beneath the JdF plate that can only be attributed to seismic anisotropy. Synthesis of the receiver function results with prior SKS splitting results requires heterogeneous anisotropy between the crust and the discontinuity. Models of anisotropy feature increasing anisotropy before the decrease at the discontinuity, but well below the base of the lithosphere, and a clockwise rotation of the fast direction with increasing depth. In these results and even in the SKS splitting results, additional driving mechanisms for mantle flow such as density or pressure anomalies are required.

  1. Fluency in native and nonnative English speech

    CERN Document Server

    Götz, Sandra

    2013-01-01

    This book takes a new and holistic approach to fluency in English speech and differentiates between productive, perceptive, and nonverbal fluency. The in-depth corpus-based description of productive fluency points out major differences of how fluency is established in native and nonnative speech. It also reveals areas in which even highly advanced learners of English still deviate strongly from the native target norm and in which they have already approximated to it. Based on these findings, selected learners are subjected to native speakers' ratings of seven perceptive fluency variables in or

  2. Native Michigan plants stimulate soil microbial species changes and PAH remediation at a legacy steel mill.

    Science.gov (United States)

    Thomas, John C; Cable, Edward; Dabkowski, Robert T; Gargala, Stephanie; McCall, Daniel; Pangrazzi, Garett; Pierson, Adam; Ripper, Mark; Russell, Donald K; Rugh, Clayton L

    2013-01-01

    A 1.3-acre phytoremediation site was constructed to mitigate polyaromatic hydrocarbon (PAH) contamination from a former steel mill in Michigan. Soil was amended with 10% (v/v) compost and 5% (v/v) poultry litter. The site was divided into twelve 11.89 m X 27.13 m plots, planted with approximately 35,000 native Michigan perennials, and soils sampled for three seasons. Soil microbial density generally increased in subplots of Eupatorium perfoliatum (boneset), Aster novae-angliae (New England aster), Andropogon gerardii (big bluestem), and Scirpus atrovirens (green bulrush) versus unplanted subplots. Using enumeration assays with root exudates, PAH degrading bacteria were greatest in soils beneath plants. Initially predominant, Arthrobacter were found capable of degrading a PAH cocktail in vitro, especially upon the addition of root exudate. Growth of some Arthrobacter isolates was stimulated by root exudate. The frequency of Arthrobacter declined in planted subplots with a concurrent increase in other species, including secondary PAH degraders Bacillus and Nocardioides. In subplots supporting only weeds, an increase in Pseudomonas density and little PAH removal were observed. This study supports the notion that a dynamic interplay between the soil, bacteria, and native plant root secretions likely contributes to in situ PAH phytoremediation.

  3. Observations and modeling of ocean-induced melt beneath Petermann Glacier Ice Shelf in northwestern Greenland

    Science.gov (United States)

    Cai, Cilan; Rignot, Eric; Menemenlis, Dimitris; Nakayama, Yoshihiro

    2017-08-01

    We update observationally based estimates of subaqueous melt, Qm, beneath Petermann Glacier Ice Shelf (PGIS), Greenland, and model its sensitivity to oceanic thermal forcing, TF, and subglacial runoff, Qsg, using the Massachusetts Institute of Technology general circulation model (MITgcm), in a two-dimensional domain, with 20 m vertical and 40 m horizontal resolution at the grounding line. We adjust the drag coefficient to match the observationally based Qm. With the inclusion of Qsg, the maximum melt rate (Qmmax) is 2 times larger in summer and 1/3 larger annually than in winter. Qmmax increases above linear with TF and below linear with Qsg. We estimate that Qmmax increased by 24% (+8.1 m/yr) beneath PGIS from the 1990s to the 2000s from a 0.21°C warming in ocean temperature and a doubling in Qsg, hence contributing to its thinning. If the PGIS is removed, we estimate that the modeled melt rate near the grounding line will increase 13-16 times.

  4. Probing seismic anisotropy in the lowermost mantle beneath the Central Atlantic Ocean

    Science.gov (United States)

    Pisconti, Angelo; Thomas, Christine; Wookey, James

    2017-04-01

    The D" region, the lowermost part of the Earth's mantle, exhibits complex structures which have been related to slabs graveyard and birth place of uprising plumes all through the mantle. These structures are likely due to flow in the mantle and investigating the anisotropy can help to determine flow and mineralogy of the D". Azimuthal anisotropy, rather than simple vertical transverse isotropy, have been recently detected using either shear wave splitting or polarities from reflected waves from the D" discontinuity. In this work, we use both methods in order to better constrain anisotropy and deformation in the lowermost mantle beneath the Atlantic Ocean. We find a reflector in the lowermost mantle that shows a complex pattern in reflected wave polarities that in some cases travel out-of-plane. Applying ScS-S differential splitting method, we also detect a tilted fast polarization. Back projecting waves to their original bounce points, modelling out of plane waves, finding cross paths and modelling of anisotropy, will help us to better understand structure and flow of the lowermost mantle beneath the Atlantic Ocean.

  5. Shear wave splitting measurements and interpretation beneath Acapulco-Tampico transect in Mexico

    Science.gov (United States)

    Stubailo, I.; Davis, P.

    2007-12-01

    We have examined shear wave splitting in teleseismic shear waves from 100 broadband stations installed from Acapulco to Tampico in Mexico over a period of 1.5 years (2005-2007). The instruments were part of the MASE (Middle America Subduction Experiment) which has the objective to build a geodynamical model of the subduction process beneath the Middle America Trench. The stations had a 5-6 km spacing and provided a unique data set which allows examination of the variation in splitting in high detail. Tomographic and receiver function studies in this area (done by MASE colleagues) show the presence of a flat slab under the western part of the array, and a steeply dipping slab beneath its center. According to geochronological data, the onset of flat slab subduction took place ~15-20 Ma, after the Cocos plate broke off the Farallon plate. We observe large splitting delay times with, on average, a fast direction in the northeast-southwest direction, but with considerable variation along the network. We compare the splitting results with the three dimensional structure inferred from the geochemistry and seismic analyses.

  6. Effect of partially demineralized dentin beneath the hybrid layer on dentin-adhesive interface micromechanics.

    Science.gov (United States)

    Anchieta, Rodolfo Bruniera; Machado, Lucas Silveira; Sundfeld, Renato Herman; Reis, André Figueiredo; Giannini, Marcelo; Luersen, Marco Antonio; Janal, Malvin; Rocha, Eduardo Passos; Coelho, Paulo G

    2015-02-26

    To investigate the presence of non-infiltrated, partially demineralized dentin (PDD) beneath the hybrid layer for self-etch adhesive systems, and its effect on micromechanical behavior of dentin-adhesive interfaces (DAIs). This in-vitro laboratory and computer simulation study hypothesized that the presence of non-infiltrated PDD beneath the hybrid layer does not influence the mechanical behavior of the DAI of self-etch adhesive systems. Fifteen sound third molars were restored with composite resin using three adhesive systems: Scotchbond Multipurpose (SBMP), Clearfil SE Bond (CSEB) and Adper Promp L-Pop (APLP). The thickness and length of all DAIs were assessed using scanning electron microscopy, and used to generate three-dimensional finite element models. Elastic moduli of the hybrid layer, adhesive layer, intertubular dentin, peritubular dentin and resin tags were acquired using a nano-indenter. Finite element software was used to determine the maximum principal stress. Mixed models analysis of variance was used to verify statistical differences (Padhesive systems, as well as the presence and extension of PDD. Both self-etch adhesive systems (APLP and CSEB) had PDD. The DAI stress levels were higher for the one-step self-etch adhesive system (APLP) compared with the etch-and-rinse adhesive system (SBMP) and the self-etch primer system (CSEB). Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Detection of latent bloodstains beneath painted surfaces using reflected infrared photography.

    Science.gov (United States)

    Farrar, Andrew; Porter, Glenn; Renshaw, Adrian

    2012-09-01

    Bloodstain evidence is a highly valued form of physical evidence commonly found at scenes involving violent crimes. However, painting over bloodstains will often conceal this type of evidence. There is limited research in the scientific literature that describes methods of detecting painted-over bloodstains. This project employed a modified digital single-lens reflex camera to investigate the effectiveness of infrared (IR) photography in detecting latent bloodstain evidence beneath a layer or multiple layers of paint. A qualitative evaluation was completed by comparing images taken of a series of samples using both IR and standard (visible light) photography. Further quantitative image analysis was used to verify the findings. Results from this project indicate that bloodstain evidence can be detected beneath up to six layers of paint using reflected IR; however, the results vary depending on the characteristics of the paint. This technique provides crime scene specialists with a new field method to assist in locating, visualizing, and documenting painted-over bloodstain evidence. © 2012 American Academy of Forensic Sciences.

  8. Slab melting beneath the Cascades Arc driven by dehydration of altered oceanic peridotite

    Science.gov (United States)

    Walowski, Kristina J; Wallace, Paul J.; Hauri, E.H.; Wada, I.; Clynne, Michael A.

    2015-01-01

    Water is returned to Earth’s interior at subduction zones. However, the processes and pathways by which water leaves the subducting plate and causes melting beneath volcanic arcs are complex; the source of the water—subducting sediment, altered oceanic crust, or hydrated mantle in the downgoing plate—is debated; and the role of slab temperature is unclear. Here we analyse the hydrogen-isotope and trace-element signature of melt inclusions in ash samples from the Cascade Arc, where young, hot lithosphere subducts. Comparing these data with published analyses, we find that fluids in the Cascade magmas are sourced from deeper parts of the subducting slab—hydrated mantle peridotite in the slab interior—compared with fluids in magmas from the Marianas Arc, where older, colder lithosphere subducts. We use geodynamic modelling to show that, in the hotter subduction zone, the upper crust of the subducting slab rapidly dehydrates at shallow depths. With continued subduction, fluids released from the deeper plate interior migrate into the dehydrated parts, causing those to melt. These melts in turn migrate into the overlying mantle wedge, where they trigger further melting. Our results provide a physical model to explain melting of the subducted plate and mass transfer from the slab to the mantle beneath arcs where relatively young oceanic lithosphere is subducted.

  9. Strong lateral variations of lithospheric mantle beneath cratons - Example from the Baltic Shield

    Science.gov (United States)

    Pedersen, H. A.; Debayle, E.; Maupin, V.

    2013-12-01

    Understanding mechanisms for creation and evolution of Precambrian continental lithosphere requires to go beyond the large-scale seismic imaging in which shields often appear as laterally homogeneous, with a thick and fast lithosphere. We here present new results from a seismic experiment (POLENET-LAPNET) in the northern part of the Baltic Shield where we identify very high seismic velocities (Vs˜4.7 km/s) in the upper part of the mantle lithosphere and a velocity decrease of ˜0.2 km/s at approximately 150 km depth. We interpret this velocity decrease as refertilisation of the lower part of the lithosphere. This result is in contrast to the lithospheric structure immediately south of the study area, where the seismic velocities within the lithosphere are fast down to 250 km depth, as well as to that of southern Norway, where there is no indication of very high velocities in the lithospheric mantle (Vs of ˜4.4 km/s). While the relatively low velocities beneath southern Norway can tentatively be attributed to the opening of the Atlantic Ocean, the velocity decrease beneath northern Finland is not easily explained with present knowledge of surface tectonics. Our results show that shield areas may be laterally heterogeneous even over relatively short distances. Such variability may in many cases be related to lithosphere erosion and/or refertilisation at the edge of cratons, which may therefore be particularly interesting targets for seismic imaging.

  10. Ambient noise adjoint tomography of the crust beneath the eastern Tibetan plateau

    Science.gov (United States)

    Zhang, D.; Chen, M.; Niu, F.; Xiong, Z.

    2016-12-01

    We present a new shear wave speed model of the crust beneath the eastern Tibetan plateau based on ambient noise adjoint tomography method [Chen et al., 2014].Instead of taking an intermediate step of measuring the surface dispersion curves in the traditional ambient noise tomography, we directly minimize the frequency-dependent travel-time misfits between the synthetic Green's functionsand the observed (empirical) Green's functions of Rayleigh waves in the period range of 10-50 s, which are extracted from two-year ambient noise data from the vertical recordings of 109 stations in the eastern Tibetan margin. The 3-D Vsv model inverted from traditional ambient noise tomography [Yang et al., 2012] is used as the initial shear wave speed model in the ambient noise adjoint tomography. The wave speed model is iteratively updated and the final model is obtained after five iterations. Frequency dependent 3-D kernels that account for off-ray path sensitivities are calculated based on adjoint methods aided by a spectral-element numerical code. Compared to the initial shear wave speed model, our new model showsmuch stronger low shear wave speed anomalies with 10% to 15% reductions at depths 15 35 km beneath the Songpan-Ganzi and the Qiangtang blocks, and much sharper wave speed contrast (up to 20%) across the boundary between the Songpan-Ganzi block and the Qaidam basin. The implications of the correlations between crustal-depth shear wave speed anomalies and the surface geological features will be discussed.

  11. New images of the crustal structure beneath eastern Tibet from a high-density seismic array

    Science.gov (United States)

    Liu, Zhen; Tian, Xiaobo; Gao, Rui; Wang, Gaochun; Wu, Zhenbo; Zhou, Beibei; Tan, Ping; Nie, Shitan; Yu, Guiping; Zhu, Gaohua; Xu, Xiao

    2017-12-01

    An east-west trending, high-density seismic array was deployed along the eastern margin of the Tibetan Plateau to investigate its eastward expansion. The 160 km long array spans the Ruoergai basin, Minjiang fault, Minshan Mountains, Tazang fault, and West Qinling. The array included 330 short-period seismographs spaced at 500 m intervals, which recorded teleseismic 3-component waveforms over a one month period. P-wave receiver functions calculated from 35 teleseismic events provided an image of crustal structure. The results show a massive thrust nappe structure around the Minshan Mountains and beneath the Minjiang fault. We suggest that this nappe formed after the closure of the Paleo-Tethyan ocean. The resultant Triassic thrusting contributed to partial uplift of the eastern Ruoergai basin and the Minshan Mountains in middle-to-late Miocene time. Receiver function images show that the Tazang fault is a crustal-scale rupture cutting across the Moho. The western Tazang fault appears as a nearly vertical strike-slip fault accommodating left lateral shear at the terminus of the eastern Kunlun fault. After clockwise rotation from an approximate east-west orientation to a nearly north-south orientation, the eastern Tazang fault became a west-dipping thrust fault, which caused crustal thickening beneath the Minshan Mountains and the West Qinling. Our results suggest that late Cenozoic uplift of the eastern margin of the plateau is produced by eastward overthrusting and crustal shortening, processes that absorbed slip along the Tazang and Kunlun faults.

  12. Unusually thickened crust beneath the Emeishan large igneous province detected by virtual deep seismic sounding

    Science.gov (United States)

    Liu, Zhen; Tian, Xiaobo; Chen, Yun; Xu, Tao; Bai, Zhiming; Liang, Xiaofeng; Iqbal, Javed; Xu, Yigang

    2017-11-01

    The Emeishan Large Igneous Province (ELIP) in southwest China represents the erosional remnant of a vast basalt field emplaced during the Permian Period. Spanning 0.25 million km2, the ELIP occupies a relatively small area relative to other Large Igneous Provinces (LIPs) such as the Siberian Traps and Ontong Java Plateau. The original volume of an ancient LIP can be constrained from estimates of its intrusive component. We used virtual deep seismic sounding (VDSS) to detect the boundary between the crust and the upper mantle (Moho) beneath the ELIP. A strong set of reflections from depths of 60-70 km indicate an unusually thick crust having a P-wave velocity of 7.0-7.4 km/s located beneath the inner zone of the ELIP. A high-velocity lower crustal body (HVLCB) of this thickness may have been formed by ponding magmas derived from the Emeishan mantle plume and associated fractionated materials. Combined images of crustal structure allow re-estimation of Emeishan magmatic volume. With a total estimated volume of 1.76-3.2 × 106 km3, the ELIP appears to have been a typical sized plume-generated LIP relative to other global examples.

  13. Structure beneath the Alboran from geodynamic flow models and seismic anisotropy

    Science.gov (United States)

    Alpert, Lisa A.; Miller, Meghan S.; Becker, Thorsten W.; Allam, Amir A.

    2013-08-01

    Upper mantle heterogeneity beneath the Alboran Sea (western Mediterranean) as inferred from seismology has been associated with a range of subduction and lithospheric delamination scenarios. However, better constraints on the deep dynamics of the region are needed to determine the cause and consequence of complex surface tectonics. Here, we use an improved set of shear wave splitting observations and a suite of mantle flow models to test a range of suggested structures. We find that the observed seismic anisotropy is best reproduced by mantle flow models that include a continuous, deeply extending slab beneath the Alboran which elongates along the Iberian margin from Granada to Gibraltar and curves southward toward the High Atlas. Other models with detached slabs, slabs with spatial gaps, or drip-like features produce results inconsistent with the splitting observations. SW-directed shear flow, when combined with sublithospheric deflection in response to a dense sinker, generates NNW-splitting orientations most similar to the patterns observed along Gibraltar. Slab viscosities of ˜250 times that of the upper mantle are preferred because they provide a balance between the poloidal flow induced by any sinker and toroidal flow induced by stiff slabs. The best match to anisotropy across the Atlas is a model with a stiff continental keel in northwestern Africa which deflects flow northward. Our results show that quantitative predictions of seismic anisotropy are useful in distinguishing the spatial and depth extent of regional density structures which may otherwise be ambiguous.

  14. Microbial oxidation as a methane sink beneath the West Antarctic Ice Sheet

    Science.gov (United States)

    Michaud, Alexander B.; Dore, John E.; Achberger, Amanda M.; Christner, Brent C.; Mitchell, Andrew C.; Skidmore, Mark L.; Vick-Majors, Trista J.; Priscu, John C.

    2017-08-01

    Aquatic habitats beneath ice masses contain active microbial ecosystems capable of cycling important greenhouse gases, such as methane (CH4). A large methane reservoir is thought to exist beneath the West Antarctic Ice Sheet, but its quantity, source and ultimate fate are poorly understood. For instance, O2 supplied by basal melting should result in conditions favourable for aerobic methane oxidation. Here we use measurements of methane concentrations and stable isotope compositions along with genomic analyses to assess the sources and cycling of methane in Subglacial Lake Whillans (SLW) in West Antarctica. We show that sub-ice-sheet methane is produced through the biological reduction of CO2 using H2. This methane pool is subsequently consumed by aerobic, bacterial methane oxidation at the SLW sediment-water interface. Bacterial oxidation consumes >99% of the methane and represents a significant methane sink, and source of biomass carbon and metabolic energy to the surficial SLW sediments. We conclude that aerobic methanotrophy may mitigate the release of methane to the atmosphere upon subglacial water drainage to ice sheet margins and during periods of deglaciation.

  15. Mantle upwelling beneath Madagascar: evidence from receiver function analysis and shear wave splitting

    Science.gov (United States)

    Paul, Jonathan D.; Eakin, Caroline M.

    2017-07-01

    Crustal receiver functions have been calculated from 128 events for two three-component broadband seismomenters located on the south coast (FOMA) and in the central High Plateaux (ABPO) of Madagascar. For each station, crustal thickness and V p / V s ratio were estimated from H- κ plots. Self-consistent receiver functions from a smaller back-azimuthal range were then selected, stacked and inverted to determine shear wave velocity structure as a function of depth. These results were corroborated by guided forward modeling and by Monte Carlo error analysis. The crust is found to be thinner (39 ± 0.7 km) beneath the highland center of Madagascar compared to the coast (44 ± 1.6 km), which is the opposite of what would be expected for crustal isostasy, suggesting that present-day long wavelength topography is maintained, at least in part, dynamically. This inference of dynamic support is corroborated by shear wave splitting analyses at the same stations, which produce an overwhelming majority of null results (>96 %), as expected for vertical mantle flow or asthenospheric upwelling beneath the island. These findings suggest a sub-plate origin for dynamic support.

  16. Anatomy of a meltwater drainage system beneath the ancestral East Antarctic ice sheet

    Science.gov (United States)

    Simkins, Lauren M.; Anderson, John B.; Greenwood, Sarah L.; Gonnermann, Helge M.; Prothro, Lindsay O.; Halberstadt, Anna Ruth W.; Stearns, Leigh A.; Pollard, David; Deconto, Robert M.

    2017-09-01

    Subglacial hydrology is critical to understand the behaviour of ice sheets, yet active meltwater drainage beneath contemporary ice sheets is rarely accessible to direct observation. Using geophysical and sedimentological data from the deglaciated western Ross Sea, we identify a palaeo-subglacial hydrological system active beneath an area formerly covered by the East Antarctic ice sheet. A long channel network repeatedly delivered meltwater to an ice stream grounding line and was a persistent pathway for episodic meltwater drainage events. Embayments within grounding-line landforms coincide with the location of subglacial channels, marking reduced sedimentation and restricted landform growth. Consequently, channelized drainage at the grounding line influenced the degree to which these landforms could provide stability feedbacks to the ice stream. The channel network was connected to upstream subglacial lakes in an area of geologically recent rifting and volcanism, where elevated heat flux would have produced sufficient basal melting to fill the lakes over decades to several centuries; this timescale is consistent with our estimates of the frequency of drainage events at the retreating grounding line. Based on these data, we hypothesize that ice stream dynamics in this region were sensitive to the underlying hydrological system.

  17. Native language, spoken language, translation and trade

    National Research Council Canada - National Science Library

    Melitz, Jacques; Toubal, Farid

    2014-01-01

    We construct new series for common native language and common spoken language for 195 countries, which we use together with series for common official language and linguistic proximity in order to draw inferences about (1...

  18. Nonverbal Communications in Native North America

    Science.gov (United States)

    Taylor, Allan Ross

    1975-01-01

    This article describes several types of native American nonspeech communications systems, including the Plains sign language, distance signaling of various kinds, picture writing and whistle speech. See FL 508 188 for availability. (CLK)

  19. Native Freshwater Fish and Mussel Species Richness

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all native freshwater fish and freshwater mussels in the Middle-Atlantic region. The data are available for...

  20. Advancing Efforts to Energize Native Alaska (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2013-04-01

    This brochure describes key programs and initiatives of the DOE Office of Indian Energy Policy and Programs to advance energy efficiency, renewable energy, and energy infrastructure projects in Alaska Native villages.

  1. American Indians, Alaska Natives, and the Flu

    Science.gov (United States)

    ... Past Emails American Indians, Alaska Natives, and the Flu Recommend on Facebook Tweet Share Compartir Vaccination against ... the flu. Protect Indian Country by Getting Your Flu Vaccine A flu vaccine not only protects you ...

  2. Broadcast News: The Absence of Native Storytellers

    National Research Council Canada - National Science Library

    Mark Trahant

    2005-01-01

      Trahant explores the consequences of Native Indians not being among those journalists who report for TV or radio stations and says improvement won't happen "until TV news recognizes the depth of the problem...

  3. 75 FR 8105 - Alaska Native Claims Selection

    Science.gov (United States)

    2010-02-23

    ... conveyance pursuant to the Alaska Native Claims Settlement Act will be issued to Zho-Tse, Incorporated. The... conveyed to Doyon, Limited, when the surface estate is conveyed to Zho-Tse, Incorporated. Notice of the...

  4. 76 FR 16805 - Alaska Native Claims Selection

    Science.gov (United States)

    2011-03-25

    ... Bristol Bay Native Corporation. The decision approves conveyance of the surface and subsurface estates in... Interest Lands Conservation Act. The lands are in the vicinity of Clarks Point, Alaska, and are located in...

  5. Modeling Magnetic Fields from a DC Power Cable Buried Beneath San Francisco Bay Based on Empirical Measurements.

    Science.gov (United States)

    Kavet, Robert; Wyman, Megan T; Klimley, A Peter

    2016-01-01

    The Trans Bay Cable (TBC) is a ±200-kilovolt (kV), 400 MW 85-km long High Voltage Direct Current (DC) buried transmission line linking Pittsburg, CA with San Francisco, CA (SF) beneath the San Francisco Estuary. The TBC runs parallel to the migratory route of various marine species, including green sturgeon, Chinook salmon, and steelhead trout. In July and August 2014, an extensive series of magnetic field measurements were taken using a pair of submerged Geometrics magnetometers towed behind a survey vessel in four locations in the San Francisco estuary along profiles that cross the cable's path; these included the San Francisco-Oakland Bay Bridge (BB), the Richmond-San Rafael Bridge (RSR), the Benicia-Martinez Bridge (Ben) and an area in San Pablo Bay (SP) in which a bridge is not present. In this paper, we apply basic formulas that ideally describe the magnetic field from a DC cable summed vectorially with the background geomagnetic field (in the absence of other sources that would perturb the ambient field) to derive characteristics of the cable that are otherwise not immediately observable. Magnetic field profiles from measurements taken along 170 survey lines were inspected visually for evidence of a distinct pattern representing the presence of the cable. Many profiles were dominated by field distortions unrelated to the cable caused by bridge structures or other submerged objects, and the cable's contribution to the field was not detectable. BB, with 40 of the survey lines, did not yield usable data for these reasons. The unrelated anomalies could be up to 100 times greater than those from the cable. In total, discernible magnetic field profiles measured from 76 survey lines were regressed against the equations, representing eight days of measurement. The modeled field anomalies due to the cable (the difference between the maximum and minimum field along the survey line at the cable crossing) were virtually identical to the measured values. The modeling

  6. Modeling Magnetic Fields from a DC Power Cable Buried Beneath San Francisco Bay Based on Empirical Measurements.

    Directory of Open Access Journals (Sweden)

    Robert Kavet

    Full Text Available The Trans Bay Cable (TBC is a ±200-kilovolt (kV, 400 MW 85-km long High Voltage Direct Current (DC buried transmission line linking Pittsburg, CA with San Francisco, CA (SF beneath the San Francisco Estuary. The TBC runs parallel to the migratory route of various marine species, including green sturgeon, Chinook salmon, and steelhead trout. In July and August 2014, an extensive series of magnetic field measurements were taken using a pair of submerged Geometrics magnetometers towed behind a survey vessel in four locations in the San Francisco estuary along profiles that cross the cable's path; these included the San Francisco-Oakland Bay Bridge (BB, the Richmond-San Rafael Bridge (RSR, the Benicia-Martinez Bridge (Ben and an area in San Pablo Bay (SP in which a bridge is not present. In this paper, we apply basic formulas that ideally describe the magnetic field from a DC cable summed vectorially with the background geomagnetic field (in the absence of other sources that would perturb the ambient field to derive characteristics of the cable that are otherwise not immediately observable. Magnetic field profiles from measurements taken along 170 survey lines were inspected visually for evidence of a distinct pattern representing the presence of the cable. Many profiles were dominated by field distortions unrelated to the cable caused by bridge structures or other submerged objects, and the cable's contribution to the field was not detectable. BB, with 40 of the survey lines, did not yield usable data for these reasons. The unrelated anomalies could be up to 100 times greater than those from the cable. In total, discernible magnetic field profiles measured from 76 survey lines were regressed against the equations, representing eight days of measurement. The modeled field anomalies due to the cable (the difference between the maximum and minimum field along the survey line at the cable crossing were virtually identical to the measured values. The

  7. Do native brown trout and non-native brook trout interact reproductively?

    Science.gov (United States)

    Cucherousset, J.; Aymes, J. C.; Poulet, N.; Santoul, F.; Céréghino, R.

    2008-07-01

    Reproductive interactions between native and non-native species of fish have received little attention compared to other types of interactions such as predation or competition for food and habitat. We studied the reproductive interactions between non-native brook trout ( Salvelinus fontinalis) and native brown trout ( Salmo trutta) in a Pyrenees Mountain stream (SW France). We found evidence of significant interspecific interactions owing to consistent spatial and temporal overlap in redd localizations and spawning periods. We observed mixed spawning groups composed of the two species, interspecific subordinate males, and presence of natural hybrids (tiger trout). These reproductive interactions could be detrimental to the reproduction success of both species. Our study shows that non-native species might have detrimental effects on native species via subtle hybridization behavior.

  8. Epistemologies in the Text of Children's Books: Native- and non-Native-authored books

    Science.gov (United States)

    Dehghani, Morteza; Bang, Megan; Medin, Douglas; Marin, Ananda; Leddon, Erin; Waxman, Sandra

    2013-09-01

    An examination of artifacts provides insights into the goals, practices, and orientations of the persons and cultures who created them. Here, we analyze storybook texts, artifacts that are a part of many children's lives. We examine the stories in books targeted for 4-8-year-old children, contrasting the texts generated by Native American authors versus popular non-Native authors. We focus specifically on the implicit and explicit 'epistemological orientations' associated with relations between human beings and the rest of nature. Native authors were significantly more likely than non-Native authors to describe humans and the rest of nature as psychologically close and embedded in relationships. This pattern converges well with evidence from a behavioral task in which we probed Native (from urban inter-tribal and rural communities) and non-Native children's and adults' attention to ecological relations. We discuss the implications of these differences for environmental cognition and science learning.

  9. Soil microbial activities beneath Stipa tenacissima L. and in surrounding bare soil

    Science.gov (United States)

    Novosadová, I.; Ruiz Sinoga, J. D.; Záhora, J.; Fišerová, H.

    2010-05-01

    Open steppes dominated by Stipa tenacissima L. constitute one of the most representative ecosystems of the semi-arid zones of Eastern Mediterranean Basin (Iberian Peninsula, North of Africa). These steppes show a higher degree of variability in composition and structure. Ecosystem functioning is strongly related to the spatial pattern of grass tussocks. Soils beneath S. tenacissima grass show higher fertility and improved microclimatic conditions, favouring the formation of "resource islands" (Maestre et al., 2007). On the other hand in "resource islands" and in surrounding bare soil exists the belowground zone of influence. The competition for water and resources between plants and microorganisms is strong and mediated trough an enormous variety of exudates and resource depletion intended to regulate soil microbial communities in the rhizosphere, control herbivory, encourage beneficial symbioses, and change chemical and physical properties in soil (Pugnaire et Armas, 2008). Secondary compounds and allelopathy restrict other species growth and contribute to patchy plant distribution. Active root segregation affects not only neighbourś growth but also soil microbial activities. The objective of this study was to assess the effect of Stipa tenacissima on the key soil microbial activities under controlled incubation conditions (basal and potential respiration; net nitrogen mineralization). The experimental plots were located in the province Almería in Sierra de los Filabres Mountains near the village Gérgal (southeast Spain) in the small catchment which is situated between 1090 - 1165 m a.s.l. The area with extent of 82 000 m2 is affected by soil degradation. The climate is semiarid Mediterranean. The mean annual rainfall is of about 240 mm mostly concentrated in autumn and spring. The mean annual temperature is 13.9° C. The studied soil has a loam to sandy clay texture and is classified as Lithosol (FAO-ISRIC and ISSS, 1998). The vegetation of these areas is an

  10. Mantle Flow Beneath the Juan de Fuca and East Pacific Rise Spreading Centers and Adjacent Plates

    Science.gov (United States)

    Toomey, D. R.; Hooft, E. E.; Wilcock, W. S.

    2010-12-01

    Observations of seismic anisotropy are a principal means of inferring the direction of mantle flow beneath tectonic plates. Azimuthal anisotropy of mantle head waves (Pn) observed in mid-plate settings, for example, has been used to infer that beneath oceanic crust the mantle flow that is frozen in is parallel to the paleospreading direction. While the agreement between historical measurements of azimuthal anisotropy and paleospreading direction is good, the combined uncertainties in experimental results (many of which date back 30 to 50 years) and in inferring the paleospreading direction are often 10-15°. In contrast to historical results from mid-plate settings, recent studies of Pn anisotropy beneath the East Pacific Rise (EPR) and the Mid-Atlantic Ridge reveal that the fast-direction of seismic anisotropy - and by inference the direction of mantle flow - is skewed with respect to the current spreading direction. This result indicates that sub-ridge mantle flow is not an entirely passive response to plate spreading. Here we use data from recent active-source seismic experiments to investigate azimuthal anisotropy of Pn arrivals in two near-ridge settings. These modern experiments, which use dense arrays of ocean-bottom seismometers (OBSs) and well-navigated seismic shooting lines, can constrain azimuthal anisotropy to within ±1°. One data set is from the multi-scale Endeavour seismic tomography experiment (ETOMO) that took place in September 2009. Seismic data were collected using 68 four-component OBSs at 64 sites and the 6600 in3 airgun array of the R/V Marcus G. Langseth. The study includes 5567 shots covering 90 km along-axis and 50 km across. The second data set is from the UNDERSHOOT experiment, which was conducted at the EPR between the Siqueiros and Clipperton transforms, a section of ridge that is sub-divided by the 9°03'N overlapping spreading center (OSC). Seismic data were collected using a combination of four-component OBSs and single

  11. Deconstructing the Native-Nonnative Dichotomy

    OpenAIRE

    Ian, WILLEY; 香川大学; Kagawa University

    2014-01-01

    Despite growing recognition of World Englishes, English curricula at Japanese universities continue to focus on native English models and assign different roles to Japanese and non-Japanese teachers. This paper reports on a study-in-progress which explores how English teachers at Japanese universities perceive and construct their own identities as English teachers in Japan. Interviews were conducted with three English-teaching participants (two native-English speakers and one Japanese). The i...

  12. Intraguild predation and native lady beetle decline.

    Science.gov (United States)

    Gardiner, Mary M; O'Neal, Matthew E; Landis, Douglas A

    2011-01-01

    Coccinellid communities across North America have experienced significant changes in recent decades, with declines in several native species reported. One potential mechanism for these declines is interference competition via intraguild predation; specifically, increased predation of native coccinellid eggs and larvae following the introduction of exotic coccinellids. Our previous studies have shown that agricultural fields in Michigan support a higher diversity and abundance of exotic coccinellids than similar fields in Iowa, and that the landscape surrounding agricultural fields across the north central U.S. influences the abundance and activity of coccinellid species. The goal of this study was to quantify the amount of egg predation experienced by a native coccinellid within Michigan and Iowa soybean fields and explore the influence of local and large-scale landscape structure. Using the native lady beetle Coleomegilla maculata as a model, we found that sentinel egg masses were subject to intense predation within both Michigan and Iowa soybean fields, with 60.7% of egg masses attacked and 43.0% of available eggs consumed within 48 h. In Michigan, the exotic coccinellids Coccinella septempunctata and Harmonia axyridis were the most abundant predators found in soybean fields whereas in Iowa, native species including C. maculata, Hippodamia parenthesis and the soft-winged flower beetle Collops nigriceps dominated the predator community. Predator abundance was greater in soybean fields within diverse landscapes, yet variation in predator numbers did not influence the intensity of egg predation observed. In contrast, the strongest predictor of native coccinellid egg predation was the composition of edge habitats bordering specific fields. Field sites surrounded by semi-natural habitats including forests, restored prairies, old fields, and pasturelands experienced greater egg predation than fields surrounded by other croplands. This study shows that intraguild

  13. Native title: Its effects on petroleum exploration

    Energy Technology Data Exchange (ETDEWEB)

    Vickery, E. [Minter Ellison Baker O`Loughlin, Adelaide, SA (Australia)

    1995-12-31

    The existence of native title in Australia was recognised by the High Court in its historic Mabo No.2 judgement on 3 June 1992. Native title is a shorthand expression used to describe those activities pursued by native peoples in connection with their traditional lands, in accordance with traditional law and custom. It could be extinguished in many ways, and once extinguished cannot be revived. Following an intense public debate, the Commonwealth enacted the Native Title Act (NTA) which, for most purposes, commenced on 1 January 1994. The NTA recognizes and protects native title, enabling its future extinguishment in only limited cases, principally by government acquisition for public purposes which are actually fulfilled. This paper discusses the meaning and application of the NTA and the Racial Discrimination Act, 1975 (RDA) together with their impact on onshore and offshore petroleum activities. It concludes that access to land and security of title are important to petroleum exploration and that exploration companies need to be aware of the conflicts between statutory exploration rights and the rights of native title holders as owners of the land. 1 photo.

  14. Perceptual prothesis in native Spanish speakers

    Science.gov (United States)

    Theodore, Rachel M.; Schmidt, Anna M.

    2003-04-01

    Previous research suggests a perceptual bias exists for native phonotactics [D. Massaro and M. Cohen, Percept. Psychophys. 34, 338-348 (1983)] such that listeners report nonexistent segments when listening to stimuli that violate native phonotactics [E. Dupoux, K. Kakehi, Y. Hirose, C. Pallier, and J. Mehler, J. Exp. Psychol.: Human Percept. Perform. 25, 1568-1578 (1999)]. This study investigated how native-language experience affects second language processing, focusing on how native Spanish speakers perceive the English clusters /st/, /sp/, and /sk/, which represent phonotactically illegal forms in Spanish. To preserve native phonotactics, Spanish speakers often produce prothetic vowels before English words beginning with /s/ clusters. Is the influence of native phonotactics also present in the perception of illegal clusters? A stimuli continuum ranging from no vowel (e.g., ``sku'') to a full vowel (e.g., ``esku'') before the cluster was used. Four final vowel contexts were used for each cluster, resulting in 12 sCV and 12 VsCV nonword endpoints. English and Spanish listeners were asked to discriminate between pairs differing in vowel duration and to identify the presence or absence of a vowel before the cluster. Results will be discussed in terms of implications for theories of second language speech perception.

  15. Apology Strategy in English By Native Speaker

    Directory of Open Access Journals (Sweden)

    Mezia Kemala Sari

    2016-05-01

    Full Text Available This research discussed apology strategies in English by native speaker. This descriptive study was presented within the framework of Pragmatics based on the forms of strategies due to the coding manual as found in CCSARP (Cross-Cultural Speech Acts Realization Project.The goals of this study were to describe the apology strategies in English by native speaker and identify the influencing factors of it. Data were collected through the use of the questionnaire in the form of Discourse Completion Test, which was distributed to 30 native speakers. Data were classified based on the degree of familiarity and the social distance between speaker and hearer and then the data of native will be separated and classified by the type of strategies in coding manual. The results of this study are the pattern of apology strategies of native speaker brief with the pattern that potentially occurs IFID plus Offer of repair plus Taking on responsibility. While Alerters, Explanation and Downgrading appear with less number of percentage. Then, the factors that influence the apology utterance by native speakers are the social situation, the degree of familiarity and degree of the offence which more complicated the mistake tend to produce the most complex utterances by the speaker.

  16. The Native Comic Book Project: native youth making comics and healthy decisions.

    Science.gov (United States)

    Montgomery, Michelle; Manuelito, Brenda; Nass, Carrie; Chock, Tami; Buchwald, Dedra

    2012-04-01

    American Indians and Alaska Natives have traditionally used stories and drawings to positively influence the well-being of their communities. The objective of this study was to describe the development of a curriculum that trains Native youth leaders to plan, write, and design original comic books to enhance healthy decision making. Project staff developed the Native Comic Book Project by adapting Dr. Michael Bitz's Comic Book Project to incorporate Native comic book art, Native storytelling, and decision-making skills. After conducting five train-the-trainer sessions for Native youth, staff were invited by youth participants to implement the full curriculum as a pilot test at one tribal community site in the Pacific Northwest. Implementation was accompanied by surveys and weekly participant observations and was followed by an interactive meeting to assess youth engagement, determine project acceptability, and solicit suggestions for curriculum changes. Six youths aged 12 to 15 (average age = 14) participated in the Native Comic Book Project. Youth participants stated that they liked the project and gained knowledge of the harmful effects of commercial tobacco use but wanted better integration of comic book creation, decision making, and Native storytelling themes. Previous health-related comic book projects did not recruit youth as active producers of content. This curriculum shows promise as a culturally appropriate intervention to help Native youth adopt healthy decision-making skills and healthy behaviors by creating their own comic books.

  17. The online application of binding condition B in native and non-native pronoun resolution

    Directory of Open Access Journals (Sweden)

    Clare ePatterson

    2014-02-01

    Full Text Available Previous research has shown that anaphor resolution in a non-native language may be more vulnerable to interference from structurally inappropriate antecedents compared to native anaphor resolution. To test whether previous findings on reflexive anaphors generalise to non-reflexive pronouns, we carried out an eye-movement monitoring study investigating the application of binding condition B during native and non-native sentence processing. In two online reading experiments we examined when during processing local and/or non-local antecedents for pronouns were considered in different types of syntactic environment. Our results demonstrate that both native English speakers and native German-speaking learners of English showed online sensitivity to binding condition B in that they did not consider syntactically inappropriate antecedents. For pronouns thought to be exempt from condition B (so-called 'short-distance pronouns', the native readers showed a weak preference for the local antecedent during processing. The non-native readers, on the other hand, showed a preference for the matrix subject even where local coreference was permitted, and despite demonstrating awareness of short-distance pronouns' referential ambiguity in a complementary offline task. This indicates that non-native comprehenders are less sensitive during processing to structural cues that render pronouns exempt from condition B, and prefer to link a pronoun to a salient subject antecedent instead.

  18. Auditory–motor interactions for the production of native and non-native speech

    Science.gov (United States)

    Jones, ‘Ōiwi Parker; Seghier, Mohamed L.; Duncan, Keith J. Kawabata; Leff, Alex P.; Green, David W.; Price, Cathy J.

    2013-01-01

    During speech production, auditory processing of self-generated speech is used to adjust subsequent articulations. The current study investigated how the proposed auditory–motor interactions are manifest at the neural level in native and non-native speakers of English who were overtly naming pictures of objects and reading their written names. Data were acquired with fMRI and analysed with dynamic causal modelling (DCM). We found that: (1) higher activity in articulatory regions caused activity in auditory regions to decrease (i.e., auditory suppression); and (2) higher activity in auditory regions caused activity in articulatory regions to increase (i.e., auditory feedback). In addition, we were able to demonstrate that: (3) speaking in a non-native language involves more auditory feedback and less auditory suppression than speaking in a native language. The difference between native and non-native speakers was further supported by finding that, within non-native speakers, there was less auditory feedback for those with better verbal fluency. Consequently, the networks of more fluent non-native speakers looked more like those of native speakers. Together, these findings provide a foundation on which to explore auditory–motor interactions during speech production in other human populations, particularly those with speech difficulties. PMID:23392667

  19. Fellow Profile

    Indian Academy of Sciences (India)

    Fellow Profile. Elected: 1971 Section: Chemistry. Narasimhan, Prof. Palliakaranai Thirumalai Ph.D. (Madras), FNA, FNASc. Date of birth: 28 July 1928. Date of death: 3 May 2013. Specialization: Theoretical Chemistry and Magnetic Resonance Last known address: 1013, Lupine Drive, Sunnyvale, CA 94086, USA. YouTube ...

  20. Evaluating Printability of Buried Native EUV Mask Phase Defects through a Modeling and Simulation Approach

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyaya, Mihir; Jindal, Vibhu; Basavalingappa, Adarsh; Herbol, Henry; Harris-Jones, Jenah; Jang, Il-Yong; Goldberg, Kenneth A.; Mochi, Iacopo; Marokkey, Sajan; Demmerle, Wolfgang; Pistor, Thomas V.; Denbeaux, Gregory

    2015-03-16

    The availability of defect-free masks is considered to be a critical issue for enabling extreme ultraviolet lithography (EUVL) as the next generation technology. Since completely defect-free masks will be hard to achieve, it is essential to have a good understanding of the printability of the native EUV mask defects. In this work, we performed a systematic study of native mask defects to understand the defect printability caused by them. The multilayer growth over native substrate mask blank defects was correlated to the multilayer growth over regular-shaped defects having similar profiles in terms of their width and height. To model the multilayer growth over the defects, a novel level-set multilayer growth model was used that took into account the tool deposition conditions of the Veeco Nexus ion beam deposition tool. The same tool was used for performing the actual deposition of the multilayer stack over the characterized native defects, thus ensuring a fair comparison between the actual multilayer growth over native defects, and modeled multilayer growth over regular-shaped defects. Further, the printability of the characterized native defects was studied with the SEMATECH-Berkeley Actinic Inspection Tool (AIT), an EUV mask-imaging microscope at Lawrence Berkeley National Laboratory (LBNL). Printability of the modeled regular-shaped defects, which were propagated up the multilayer stack using level-set growth model was studied using defect printability simulations implementing the waveguide algorithm. Good comparison was observed between AIT and the simulation results, thus demonstrating that multilayer growth over a defect is primarily a function of a defect’s width and height, irrespective of its shape. This would allow us to predict printability of the arbitrarily-shaped native EUV mask defects in a systematic and robust manner.

  1. Seismic Anisotropy due to Crust and Uppermost Mantle Deformation Beneath Southern Peru and Bolivia: Constraints from Receiver Functions

    Science.gov (United States)

    Bar, N.; Long, M. D.; Wagner, L. S.; Beck, S. L.; Tavera, H.

    2016-12-01

    Subduction systems play a key role in plate tectonics, but the deformation of the crust and uppermost mantle during subduction and orogenesis in continental subduction systems remains poorly understood. Observations of seismic anisotropy can provide important constraints on dynamic processes in the crust and uppermost mantle in subduction systems. The subduction zone beneath Peru and Bolivia, where the Nazca plate subducts beneath South America, represents a particularly interesting location to study subduction-related deformation, given the complex slab morphology and the along-strike transition from flat to normally dipping subduction. In particular, understanding the structure and deformation of the crust and mantle will yield insight into the relationship between the flat slab and the overriding continental lithosphere. In this study we constrain seismic anisotropy within and above the subducting slab (including the mantle wedge and the overriding plate) beneath southern Peru and Bolivia using transverse component receiver functions. Because anisotropic receiver function analysis can constrain the depth distribution of anisotropy, this analysis is complementary to previous studies of shear wave splitting in this region. We examine data from two dense lines of seismometers from the PULSE and CAUGHT deployments in Peru and Bolivia, each anchored by a long-running permanent station. The northern line overlies the Peru flat slab, while the southern line overlies the normally dipping slab beneath Bolivia. Beneath Peru, our investigation of anisotropic structure along the flat slab will help test the recently suggested hypothesis of a slab tear; beneath Bolivia, we aim to characterize the pattern of flow in the mantle wedge as well as the nature of deformation in the lower crust of the overriding plate.

  2. Factors contributing to the temperature beneath plaster or fiberglass cast material

    Directory of Open Access Journals (Sweden)

    Hutchinson Mark R

    2008-02-01

    Full Text Available Abstract Background Most cast materials mature and harden via an exothermic reaction. Although rare, thermal injuries secondary to casting can occur. The purpose of this study was to evaluate factors that contribute to the elevated temperature beneath a cast and, more specifically, evaluate the differences of modern casting materials including fiberglass and prefabricated splints. Methods The temperature beneath various types (plaster, fiberglass, and fiberglass splints, brands, and thickness of cast material were measured after they were applied over thermometer which was on the surface of a single diameter and thickness PVC tube. A single layer of cotton stockinette with variable layers and types of cast padding were placed prior to application of the cast. Serial temperature measurements were made as the cast matured and reached peak temperature. Time to peak, duration of peak, and peak temperature were noted. Additional tests included varying the dip water temperature and assessing external insulating factors. Ambient temperature, ambient humidity and dip water freshness were controlled. Results Outcomes revealed that material type, cast thickness, and dip water temperature played key roles regarding the temperature beneath the cast. Faster setting plasters achieved peak temperature quicker and at a higher level than slower setting plasters. Thicker fiberglass and plaster casts led to greater peak temperature levels. Likewise increasing dip-water temperature led to elevated temperatures. The thickness and type of cast padding had less of an effect for all materials. With a definition of thermal injury risk of skin injury being greater than 49 degrees Celsius, we found that thick casts of extra fast setting plaster consistently approached dangerous levels (greater than 49 degrees for an extended period. Indeed a cast of extra-fast setting plaster, 20 layers thick, placed on a pillow during maturation maintained temperatures over 50 degrees of

  3. Lithospheric discontinuities beneath the U.S. Midcontinent - signatures of Proterozoic terrane accretion and failed rifting

    Science.gov (United States)

    Chen, Chen; Gilbert, Hersh; Fischer, Karen M.; Andronicos, Christopher L.; Pavlis, Gary L.; Hamburger, Michael W.; Marshak, Stephen; Larson, Timothy; Yang, Xiaotao

    2018-01-01

    Seismic discontinuities between the Moho and the inferred lithosphere-asthenosphere boundary (LAB) are known as mid-lithospheric discontinuities (MLDs) and have been ascribed to a variety of phenomena that are critical to understanding lithospheric growth and evolution. In this study, we used S-to-P converted waves recorded by the USArray Transportable Array and the OIINK (Ozarks-Illinois-Indiana-Kentucky) Flexible Array to investigate lithospheric structure beneath the central U.S. This region, a portion of North America's cratonic platform, provides an opportunity to explore how terrane accretion, cratonization, and subsequent rifting may have influenced lithospheric structure. The 3D common conversion point (CCP) volume produced by stacking back-projected Sp receiver functions reveals a general absence of negative converted phases at the depths of the LAB across much of the central U.S. This observation suggests a gradual velocity decrease between the lithosphere and asthenosphere. Within the lithosphere, the CCP stacks display negative arrivals at depths between 65 km and 125 km. We interpret these as MLDs resulting from the top of a layer of crystallized melts (sill-like igneous intrusions) or otherwise chemically modified lithosphere that is enriched in water and/or hydrous minerals. Chemical modification in this manner would cause a weak layer in the lithosphere that marks the MLDs. The depth and amplitude of negative MLD phases vary significantly both within and between the physiographic provinces of the midcontinent. Double, or overlapping, MLDs can be seen along Precambrian terrane boundaries and appear to result from stacked or imbricated lithospheric blocks. A prominent negative Sp phase can be clearly identified at 80 km depth within the Reelfoot Rift. This arrival aligns with the top of a zone of low shear-wave velocities, which suggests that it marks an unusually shallow seismic LAB for the midcontinent. This boundary would correspond to the top of a

  4. Factors contributing to the temperature beneath plaster or fiberglass cast material.

    Science.gov (United States)

    Hutchinson, Michael J; Hutchinson, Mark R

    2008-02-25

    Most cast materials mature and harden via an exothermic reaction. Although rare, thermal injuries secondary to casting can occur. The purpose of this study was to evaluate factors that contribute to the elevated temperature beneath a cast and, more specifically, evaluate the differences of modern casting materials including fiberglass and prefabricated splints. The temperature beneath various types (plaster, fiberglass, and fiberglass splints), brands, and thickness of cast material were measured after they were applied over thermometer which was on the surface of a single diameter and thickness PVC tube. A single layer of cotton stockinette with variable layers and types of cast padding were placed prior to application of the cast. Serial temperature measurements were made as the cast matured and reached peak temperature. Time to peak, duration of peak, and peak temperature were noted. Additional tests included varying the dip water temperature and assessing external insulating factors. Ambient temperature, ambient humidity and dip water freshness were controlled. Outcomes revealed that material type, cast thickness, and dip water temperature played key roles regarding the temperature beneath the cast. Faster setting plasters achieved peak temperature quicker and at a higher level than slower setting plasters. Thicker fiberglass and plaster casts led to greater peak temperature levels. Likewise increasing dip-water temperature led to elevated temperatures. The thickness and type of cast padding had less of an effect for all materials. With a definition of thermal injury risk of skin injury being greater than 49 degrees Celsius, we found that thick casts of extra fast setting plaster consistently approached dangerous levels (greater than 49 degrees for an extended period). Indeed a cast of extra-fast setting plaster, 20 layers thick, placed on a pillow during maturation maintained temperatures over 50 degrees of Celsius for over 20 minutes. Clinicians should be

  5. A Dynamical Context for Small-scale Heterogeneity Throughout the Mantle Beneath Subduction

    Science.gov (United States)

    Frost, D. A.; Rost, S.; Garnero, E.

    2014-12-01

    Subduction zones are a source for mantle heterogeneity within the convection system and there is mounting evidence that seismic signatures can be used to track slabs down from the surface throughout the mantle. Seismic studies of the mantle beneath Central America demonstrate that subducted slab material reaches the Core-Mantle Boundary (CMB). The lowermost mantle beneath this convergent margin shows strong seismic evidence for heterogeneity. Tomographic models characterise subduction zones to be underlain by increased seismic velocities over 100s-1000s km laterally, in association with D'´ discontinuities 100-300 km above the CMB, consistent with phase transitions in the Bridgmanite system. Recent analyses have found evidence for isolated Ultra Low Velocity Zones in addition to prevalent fine-scale heterogeneity, on the order of 1-10 km, scattering high frequency waves. These techniques indicate thermal and/or chemical anomalies within the mantle on a range of scales. Numerical geodynamical simulations suggest small-scale mechanical mixing of initially coherent compositionally anomalous subducted material separating into entities of various sizes consistent with the range of heterogeneity sizes observed in the lower mantle.Investigating seismic scattering, the re-radiation of a wavefront due to interaction with a sharply contrasting volumetric anomaly, is an effective method for studying small-scale elastic heterogeneities in the Earth's mantle. Studies commonly record structure with scale lengths of about 10 km. Here we analyse scattered energy related to PKPPKP — PKP•PKP (the • indicates the scattering location along the raypath) — sampling a large volume of the mantle beneath Central America. We reveal the character of heterogeneity in various frequency bands within the whole mantle using both broadband and short-period data. These observations will be placed in context with other studies in this region illustrating the large-scale background structure

  6. Seismic evidence of the lithosphere-asthenosphere boundary beneath Izu-Bonin area

    Science.gov (United States)

    Cui, H.; Gao, Y.; Zhou, Y.

    2016-12-01

    The lithosphere-asthenosphere boundary (LAB), separating the rigid lithosphere and the ductile asthenosphere layers, is the seismic discontinuity with the negative velocity contrast of the Earth's interior [Fischer et al., 2010]. The LAB has been also termed the Gutenberg (G) discontinuity that defines the top of the low velocity zone in the upper mantle [Gutenberg, 1959; Revenaugh and Jordan, 1991]. The seismic velocity, viscosity, resistivity and other physical parameters change rapidly with the depths across the boundary [Eaton et al., 2009]. Seismic detections on the LAB in subduction zone regions are of great help to understand the interactions between the lithosphere and asthenosphere layers and the geodynamic processes related with the slab subductions. In this study, the vertical broadband waveforms are collected from three deep earthquake events occurring from 2000 to 2014 with the focal depths of 400 600 km beneath the Izu-Bonin area. The waveform data is processed with the linear slant stack method [Zang and Zhou, 2002] to obtain the vespagrams in the relative travel-time to slowness domain and the stacked waveforms. The sP precursors reflected on the LAB (sLABP), which have the negative polarities with the amplitude ratios of 0.17 0.21 relative to the sP phases, are successfully extracted. Based on the one-dimensional modified velocity model (IASP91-IB), we obtain the distributions for six reflected points of the sLABP phases near the source region. Our results reveal that the LAB depths range between 58 and 65 km beneath the Izu-Bonin Arc, with the average depth of 62 km and the small topography of 7 km. Compared with the results of the tectonic stable areas in Philippine Sea [Kawakatsu et al., 2009; Kumar and Kawakatsu, 2011], the oceanic lithosphere beneath the Izu-Bonin Arc shows the obvious thinning phenomena. We infer that the lithospheric thinning is closely related with the partial melting, which is caused by the volatiles continuously released

  7. One and two-dimensional Triplicated waveform modeling beneath northeast Asia

    Science.gov (United States)

    Lai, Y.; Chen, L.

    2016-12-01

    Northeast Asia has long been investigated by geoscientists for its critical importance where the Pacific plate is subducting beneath the Eurasian continent accompanying by complicated mantle processes. In our study, taking advantages of frequent occurrence of deep earthquakes(>300km) in the subduction zone and dense seismic arrays in mainland China and Japan, we conducted both 1-Dimensional (1-D) and 2-Dimensional (2-D) triplicated forward waveform modeling on several selected deep events in the Japan-kuril and Izu areas. Triplicated waveform or Triplication which consists of refracted and reflected wave caused by the 410km/660km discontinuity, is very sensitive to the mantle transition zone velocity structure compared with the most commonly adopted methods such as receiver functions and seismic tomography. From 1-D modeling, we obtained the 1-D P and SH wave velocity structure model in the research area, which has an average P wave velocity 1% with maximum 2.1% and an average SH wave velocity 2% with maximum 3.9% higher than the global Iasp91 model in the mantle transition zone, consistent with the tomographic image of a fast stagnant slab in the region. In addition, we found slightly low velocities at approximately 560 km depth. However, the distribution and properties of such a low velocity feature cannot be well constrained based purely on the simple 1-D waveform modeling. In our 2-D simulations, we constructed a series of models and adopted the SEM method to investigate the sensitivity of triplicated waveforms on the slab structure in the mantle transition zone. In particular, we tested a model with a low velocity metastable olivine wedge (mow) added in the slab in the case that seismic waves travel roughly along the trending direction of the steep slab beneath the Izu Arc. Our preliminary result shows that the synthetic seismograms with the mow model display waveform variations distinctly different from the observations, suggesting that a metastable olivine

  8. Crustal Structure Beneath the Tibetan Plateau Using Receiver Functions and Surface Wave Dispersion Observations

    Science.gov (United States)

    Diehl, T.; Ammon, C. J.; Mejia, J.

    2002-12-01

    Despite substantial effort, some uncertainty in the bulk crustal geology beneath the Tibetan Plateau remains. Recent experiments have provided a wealth of seismic data for investigating structures within the Tibetan lithosphere. We investigate the subsurface Tibetan geology using receiver functions from the 1991-1992 Passive Source and the 1997-1999 INDEPTH III experiments. We have completed joint inversions of surface-wave dispersion and select receiver functions for the older data and plan to explore and invert receiver functions from select stations from the INDEPTH III experiment. The combination of receiver functions with surface-wave dispersion does much to improve P- and S-velocity structure resolution, but modeling is most appropriate for relatively simple structures. We begin our analyses with the depth-velocity stacking estimation of Zhu and Kanamori [2000] where we attempt to extract thickness, P-velocity, and Vp/Vs ratios compatible with the move-out of the Ps conversion and multiples from velocity contrasts within the lithosphere. Again, the main limitation of the technique is the assumption of a simple structure to insure consistency with a set of straightforward travel-time equations used to compute arrival-time move-out (as a function of incident-wave ray parameter). Poisson's ratio values from the 1991-1992 deployment were difficult to extract because of complex structure. The station with simplest response, WNDO, suggests a ratio of 0.28 beneath the north-central Plateau, which is slightly above average for continental crust. These results are lower than some earlier values which suggested that the lower crust beneath central and northern Tibet may contain substantial partial melt. The joint inversion of the simplest available receiver functions, and global long-period and local short-period surface-wave dispersion observations suggests that the crustal thickness for the northern Plateau ranges from 60-70 km (stations ERDO, BUDO, TUNL). Thickness

  9. Treatment of Chlorinated Solvents in Groundwater Beneath an Occupied Building at the Young-Rainey STAR Center, Pinellas, FL

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Joe [Navarro Research and Engineering; Surovchak, Scott [Dept. of Energy (DOE), Legacy Management; Tabor, Charles [Navarro Research and Engineering

    2016-03-01

    Groundwater contamination, consisting of two dissolved-phase plumes originating from chlorinated solvent source areas, in the southeastern portion of the Young- Rainey Star Center (also known as the Pinellas County, Florida, Site) in Largo, Florida, has migrated beyond the property boundary, beneath the roadways, and beneath adjacent properties to the south and east. Groundwater contamination will persist as long as the onsite contaminant source remains. The origin of the contamination appears to be multiple long-term point sources beneath Building 100, a 4.5 ha (11 acre) building that housed manufacturing facilities during US DOE operations at the site. The site is now owned by Pinellas County, and most of the space inside the building is leased to private companies, so DOE chose not to conduct characterization or remediation through the floor of the building, instead choosing to conduct all work from outside the building. Injection of emulsified soybean oil and a microbial culture has been used at other areas of the site to accelerate naturally occurring bacterial processes that degrade groundwater contaminants to harmless compounds, and that same approach was chosen for this task. The technical approach consisted of installing horizontal wells from outside the building footprint, extending through and around the identified subsurface treatment areas, and terminating beneath the building. Two 107 m (350 ft) long wells, two 122 m (400 ft) long wells, and four 137 m (450 ft) long wells have been installed to intersect the inferred source areas and confirmed contaminant plumes beneath the building. DOE then injected emulsified vegetable oil and a microbial culture into the horizontal wells at each of several target areas beneath the building where the highest groundwater contaminant concentrations have been detected. The target areas are the northwest corner of the building between the old drum storage pad locations and monitoring well PIN12-S35B, the vicinity of

  10. New constraints on the textural and geochemical evolution of the upper mantle beneath the Styrian basin

    Science.gov (United States)

    Aradi, Laszlo; Hidas, Károly; Zanetti, Alberto; János Kovács, István; Patkó, Levente; Szabó, Csaba

    2016-04-01

    Plio-Pleistocene alkali basaltic volcanism sampled sporadically the upper mantle beneath the Carpathian-Pannonian Region (CPR, e.g. [1]). Lavas and pyroclasts often contain mantle derived xenoliths, and the majority of them have been extensively studied [1], except the westernmost Styrian Basin Volcanic Field (SBVF, Eastern Austria and Slovenia). In the SBVF only a few volcanic centers have been studied in details (e.g. Kapfenstein & Tobaj). Based on these studies, the upper mantle beneath the SBVF is consists of dominantly high temperature, texturally and geochemically homogeneous protogranular spinel lherzolite. New major and trace element data from rock-forming minerals of ultramafic xenoliths, coupled with texture and deformation analysis from 12 volcanic outcrops across the SBVF, suggest that the lithospheric roots of the region are more heterogeneous than described previously. The studied xenoliths are predominantly lherzolite, amphibole is a common phase that replaces pyroxenes and spinels and proves modal metasomatism. Phlogopite coupled with apatite is also present in amphibole-rich samples. The texture of the xenoliths is usually coarse-grained and annealed with low abundance of subgrain boundaries in both olivine and pyroxenes. Olivine crystal preferred orientation (CPO) varies between the three most abundant one: [010]-fiber, orthogonal and [100]-fiber symmetry [2]. The CPO of pyroxenes is usually coherent with coeval deformation with olivine, however the CPO of amphibole is suggesting postkinematic epitaxial overgrowth on the precursor pyroxenes. According to equilibrium temperatures, the studied xenolith suite samples a broader temperature range (850-1100 °C) than the literature data, corresponding to mantle depths between 30 and 60 km, which indicates that the xenolith suite only represents the shallower part of the recent 100 km thick lithospheric mantle beneath the SBVF. The equilibrium temperatures show correlation with the varying CPO symmetries

  11. Detailed crustal thickness variations beneath the Illinois Basin area: Implications for crustal evolution of the midcontinent

    Science.gov (United States)

    Yang, Xiaotao; Pavlis, Gary L.; Hamburger, Michael W.; Marshak, Stephen; Gilbert, Hersh; Rupp, John; Larson, Timothy H.; Chen, Chen; Carpenter, N. Seth

    2017-08-01

    We present high-resolution imaging results of crustal and upper mantle velocity discontinuities across the Illinois Basin area using both common conversion point stacking and plane wave migration methods applied to P wave receiver functions from the EarthScope Ozark, Illinois, Indiana, and Kentucky experiment. The images reveal unusually thick crust (up to 62 km) throughout the central and southeastern Illinois Basin area. A significant Moho gradient underlies the NW trending Ste. Genevieve Fault Zone, which delineates the boundary between the Illinois Basin and Ozark Dome. Relatively thinner crust (Proterozoic convergent margin tectonics around 1.55-1.35 Ga; (3) by Late Precambrian magmatic underplating at the base of older crust, associated with the creation of the Eastern Granite-Rhyolite Province around 1.3 Ga; and (4) through crustal "relamination" during an episode of Proterozoic flat-slab subduction beneath the Illinois Basin, possibly associated with the Grenville Orogeny.

  12. Os and HSE of the hot upper mantle beneath southern Tibet: Indian mantle affinity?

    Science.gov (United States)

    Zhao, Z.; Dale, C. W.; Pearson, D. G.; Niu, Y.; Zhu, D.; Mo, X.

    2011-12-01

    The subduction of the Indian plate (including cratonic continental crust and/or upper mantle) beneath southern Tibet is widely accepted from both geological and geophysical studies. Mantle-derived xenoliths from this region provide a means of directly investigating the mantle underlying the southern part of the plateau. Studies of xenoliths hosted in the Sailipu ultrapotassic volcanic rocks, erupted at ~17 Ma, have indicated that the subcontinental mantle of southern Tibetan Plateau is hot and strongly influenced by metasomatism (Zhao et al., 2008a, b; Liu et al., 2011). Here we report comprehensive EPMA and LA-ICP-MS major and trace element data for the Sailipu xenoliths and also whole rock Os isotope and HSE data in order to constrain the depletion history of the mantle and to identify the presence of any potential Indian cratonic mantle. The xenoliths, ranging in size from 0.5cm to 1.5cm in diameter, are mostly peridotites. The calculated temperatures are 1010-1230°C at the given pressures of ~1.6-2.0 GPa (n=47). These P-T conditions are similar to rift-related upper mantle regimes (e.g. Kenya), indicating the influence of regional extension beneath southern Tibet in the Miocene. A series of compositional discriminations for minerals (Cpx, Opx, Ol, and Phl), e.g. Fo ~91), with a clear metasomatic signature We obtained Os isotope data and abundances of highly siderophile elements (HSE, including Os, Ir, Ru, Pt, Pd and Re) on a set of six olivine-dominated peridotite samples from Sailipu volcanics, less than 1 cm in dimension. They allow us to further constrain the nature and state of the upper mantle beneath the southern Tibet. Sailipu samples display low total HSE abundances (Os+Ir+Ru+Pt+Pd+Re) ranging from 8.7 to 25 ppb, with nearly constant Os, Ir , and Ru, but rather varied Pt (2-13), Pd (0.4-5.2), and Re (0.01-0.5). Chondrite-normalised Pd/Ir ratios range from 0.2 to 2.4 reflecting significant metasomatism of some samples. The xenoliths exhibit 187Os/188Os

  13. Radiological status of the ground water beneath the Hanford Site, January-December 1980

    Energy Technology Data Exchange (ETDEWEB)

    Eddy, P. A.; Wilbur, J. S.

    1981-04-01

    Operations at the Hanford Site since 1944 have resulted in the discharge to the ground of large volumes of process cooling water and low-level liquid radioactive waste. Radioactivity and chemical substances have been carried with these discharges and have reached the Hanford ground water. For many years wells have been used as ground-water sampling structures to gather data on the distribution and movement of these discharges as they interact with the unconfined ground water beneath the Hanford Site. During 1980, 317 such structures were sampled at various times for radionuclide and chemical contaminants. Data collected during 1980 describe the movement of tritium and ruthenium-106 and the nonradioactive nitrate plume as well as their response to the influences of ground-water flow, ionic dispersion, and radioactive decay.

  14. Indicators of sewage contamination in sediments beneath a deep-ocean dump site off New York

    Science.gov (United States)

    Bothner, Michael H.; Takada, H.; Knight, I.T.; Hill, R.T.; Butman, B.; Farrington, J.W.; Colwell, R.R.; Grassle, J. F.

    1994-01-01

    The world's largest discharge of municipal sewage sludge to surface waters of the deep sea has caused measurable changes in the concentration of sludge indicators in sea-floor sediments, in a spatial pattern which agrees with the predictions of a recent sludge deposition model. Silver, linear alkylbenzenes, coprostanol, and spores of the bacterium Clostridium perfringens, in bottom sediments and in near-bottom suspended sediment, provide evidence for rapid settling of a portion of discharged solids, accumulation on the sea floor, and biological mixing beneath the water sediment interface. Biological effects include an increase in 1989 of two species of benthic polychaete worm not abundant at the dump site before sludge dumping began in 1986. These changes in benthic ecology are attributed to the increased deposition of utilizable food in the form of sludge-derived organic matter.

  15. Deep groundwater and potential subsurface habitats beneath an Antarctic dry valley.

    Science.gov (United States)

    Mikucki, J A; Auken, E; Tulaczyk, S; Virginia, R A; Schamper, C; Sørensen, K I; Doran, P T; Dugan, H; Foley, N

    2015-04-28

    The occurrence of groundwater in Antarctica, particularly in the ice-free regions and along the coastal margins is poorly understood. Here we use an airborne transient electromagnetic (AEM) sensor to produce extensive imagery of resistivity beneath Taylor Valley. Regional-scale zones of low subsurface resistivity were detected that are inconsistent with the high resistivity of glacier ice or dry permafrost in this region. We interpret these results as an indication that liquid, with sufficiently high solute content, exists at temperatures well below freezing and considered within the range suitable for microbial life. These inferred brines are widespread within permafrost and extend below glaciers and lakes. One system emanates from below Taylor Glacier into Lake Bonney and a second system connects the ocean with the eastern 18 km of the valley. A connection between these two basins was not detected to the depth limitation of the AEM survey (∼350 m).

  16. Preliminary results of characteristic seismic anisotropy beneath Sunda-Banda subduction-collision zone

    Energy Technology Data Exchange (ETDEWEB)

    Wiyono, Samsul H., E-mail: samsul.wiyono@bmkg.go.id [Study Program of Earth Sciences, Faculty of Earth Sciences and Technology, Institute of Technology Bandung, Bandung 40132 (Indonesia); Indonesia’s Agency for Meteorology Climatology and Geophysics, Jakarta 10610 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Indonesia’s Agency for Meteorology Climatology and Geophysics, Jakarta 10610 (Indonesia); Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Bandung 40132, Indonesia, Phone: +62-22 2534137 (Indonesia)

    2015-04-24

    Determining of seismic anisotropy allowed us for understanding the deformation processes that occured in the past and present. In this study, we performed shear wave splitting to characterize seismic anisotropy beneath Sunda-Banda subduction-collision zone. For about 1,610 XKS waveforms from INATEWS-BMKG networks have been analyzed. From its measurements showed that fast polarization direction is consistent with trench-perpendicular orientation but several stations presented different orientation. We also compared between fast polarization direction with absolute plate motion in the no net rotation and hotspot frame. Its result showed that both absolute plate motion frame had strong correlation with fast polarization direction. Strong correlation between the fast polarization direction and the absolute plate motion can be interpreted as the possibility of dominant anisotropy is in the asthenosphere.

  17. Cross-language perception of Cantonese vowels spoken by native and non-native speakers.

    Science.gov (United States)

    So, Connie K; Attina, Virginie

    2014-10-01

    This study examined the effect of native language background on listeners' perception of native and non-native vowels spoken by native (Hong Kong Cantonese) and non-native (Mandarin and Australian English) speakers. They completed discrimination and an identification task with and without visual cues in clear and noisy conditions. Results indicated that visual cues did not facilitate perception, and performance was better in clear than in noisy conditions. More importantly, the Cantonese talker's vowels were the easiest to discriminate, and the Mandarin talker's vowels were as intelligible as the native talkers' speech. These results supported the interlanguage speech native intelligibility benefit patterns proposed by Hayes-Harb et al. (J Phonetics 36:664-679, 2008). The Mandarin and English listeners' identification patterns were similar to those of the Cantonese listeners, suggesting that they might have assimilated Cantonese vowels to their closest native vowels. In addition, listeners' perceptual patterns were consistent with the principles of Best's Perceptual Assimilation Model (Best in Speech perception and linguistic experience: issues in cross-language research. York Press, Timonium, 1995).

  18. Defining "Native Speaker" in Multilingual Settings: English as a Native Language in Asia

    Science.gov (United States)

    Hansen Edwards, Jette G.

    2017-01-01

    The current study examines how and why speakers of English from multilingual contexts in Asia are identifying as native speakers of English. Eighteen participants from different contexts in Asia, including Singapore, Malaysia, India, Taiwan, and The Philippines, who self-identified as native speakers of English participated in hour-long interviews…

  19. Patterns of English phoneme confusions by native and non-native listeners

    NARCIS (Netherlands)

    Cutler, A.; Weber, A.C.; Smits, R.; Cooper, N.

    2004-01-01

    Native American English and non-native (Dutch) listeners identified either the consonant or the vowel in all possible American English CV and VC syllables. The syllables were embedded in multispeaker babble at three signal-to-noise ratios (0, 8, and 16 dB). The phoneme identification performance of

  20. An invasive non-native mammal population conserves genetic diversity lost from its native range.

    Science.gov (United States)

    Veale, A J; Holland, O J; McDonald, R A; Clout, M N; Gleeson, D M

    2015-05-01

    Invasive, non-native species are one of the major causes of global biodiversity loss. Although they are, by definition, successful in their non-native range, their populations generally show major reductions in their genetic diversity during the demographic bottleneck they experience during colonization. By investigating the mitochondrial genetic diversity of an invasive non-native species, the stoat Mustela erminea, in New Zealand and comparing it to diversity in the species' native range in Great Britain, we reveal the opposite effect. We demonstrate that the New Zealand stoat population contains four mitochondrial haplotypes that have not been found in the native range. Stoats in Britain rely heavily on introduced rabbits Oryctolagus cuniculus as their primary prey and were introduced to New Zealand in a misguided attempt at biological control of rabbits, which had also been introduced there. While invasive stoats have since decimated the New Zealand avifauna, native stoat populations were themselves decimated by the introduction to Britain of Myxoma virus as a control measure for rabbits. We highlight the irony that while introduced species (rabbits) and subsequent biocontrol (myxomatosis) have caused population crashes of native stoats, invasive stoats in New Zealand, which were also introduced for biological control, now contain more genetic haplotypes than their most likely native source. © 2015 John Wiley & Sons Ltd.

  1. University Students' Perceptions of the Influence of Native and Non-Native Teachers

    Science.gov (United States)

    Alseweed, Mohammad A.

    2012-01-01

    This paper reports the outcome of a study carried out in Qassim University with 169 Saudi male novice university students to obtain a deeper insight into their perceptions of their native English speaker teachers (NESTs) and non-native English speaker teachers (NNESTs) in the English language classroom. Quantitative and qualitative data were…

  2. Phonological Representations in Children's Native and Non-native Lexicon

    Science.gov (United States)

    Simon, Ellen; Sjerps, Matthias J.; Fikkert, Paula

    2014-01-01

    This study investigated the phonological representations of vowels in children's native and non-native lexicons. Two experiments were mispronunciation tasks (i.e., a vowel in words was substituted by another vowel from the same language). These were carried out by Dutch-speaking 9-12-year-old children and Dutch-speaking adults, in their…

  3. Vulnerability of freshwater native biodiversity to non-native species invasions across the continental United States

    Science.gov (United States)

    Background/Question/Methods Non-native species pose one of the greatest threats to native biodiversity. The literature provides plentiful empirical and anecdotal evidence of this phenomenon; however, such evidence is limited to local or regional scales. Employing geospatial analy...

  4. Sensitivity to Crossover Constraints during Native and Non-Native Pronoun Resolution

    Science.gov (United States)

    Felser, Claudia; Drummer, Janna-Deborah

    2017-01-01

    We report the results from two experiments examining native and non-native German speakers' sensitivity to crossover constraints on pronoun resolution. Our critical stimuli sentences contained personal pronouns in either strong (SCO) or weak crossover (WCO) configurations. Using eye-movement monitoring during reading and a gender-mismatch…

  5. 77 FR 72832 - Applications for New Awards; Native American and Alaska Native Children in School Program

    Science.gov (United States)

    2012-12-06

    ... English Language Acquisition, Department of Education. Overview Information Native American and Alaska... English among English learners (ELs),\\1\\ and to promote parental and community participation in language... amended (ESEA), may support the teaching and studying of Native American languages, but must have, as a...

  6. When the Native Is Also a Non-Native: "Retrodicting" the Complexity of Language Teacher Cognition

    Science.gov (United States)

    Aslan, Erhan

    2015-01-01

    The impact of native (NS) and non-native speaker (NNS) identities on second or foreign language teachers' cognition and practices in the classroom has mainly been investigated in ESL/EFL contexts. Using complexity theory as a framework, this case study attempts to fill the gap in the literature by presenting a foreign language teacher in the…

  7. Compliment Responses: Comparing American Learners of Japanese, Native Japanese Speakers, and American Native English Speakers

    Science.gov (United States)

    Tatsumi, Naofumi

    2012-01-01

    Previous research shows that American learners of Japanese (AJs) tend to differ from native Japanese speakers in their compliment responses (CRs). Yokota (1986) and Shimizu (2009) have reported that AJs tend to respond more negatively than native Japanese speakers. It has also been reported that AJs' CRs tend to lack the use of avoidance or…

  8. Less-Detailed Representation of Non-Native Language: Why Non-Native Speakers' Stories Seem More Vague

    Science.gov (United States)

    Lev-Ari, Shiri; Keysar, Boaz

    2012-01-01

    The language of non-native speakers is less reliable than the language of native speakers in conveying the speaker's intentions. We propose that listeners expect such reduced reliability and that this leads them to adjust the manner in which they process and represent non-native language by representing non-native language in less detail.…

  9. Formation of magmatic brine lenses via focussed fluid-flow beneath volcanoes

    Science.gov (United States)

    Afanasyev, Andrey; Blundy, Jon; Melnik, Oleg; Sparks, Steve

    2018-03-01

    Many active or dormant volcanoes show regions of high electrical conductivity at depths of a few kilometres beneath the edifice. We explore the possibility that these regions represent lenses of high-salinity brine separated from a single-phase magmatic fluid containing H2O and NaCl. Since chloride-bearing fluids are highly conductive and have an exceptional capacity to transport metals, these regions can be an indication of an active hydrothermal ore-formation beneath volcanoes. To investigate this possibility we have performed hydrodynamic simulations of magma degassing into permeable rock. In our models the magma source is located at 7 km depth and the fluid salinity approximates that expected for fluids released from typical arc magmas. Our model differs from previous models of a similar process because it is (a) axisymmetric and (b) includes a static high-permeability pathway that links the magma source to the surface. This pathway simulates the presence of a volcanic conduit and/or plexus of feeder dykes that are typical of most volcanic systems. The presence of the conduit leads to a number of important hydrodynamic consequences, not observed in previous models. Importantly, we show that an annular brine lens capped by crystallised halite is likely to form above an actively degassing sub-volcanic magma body and can persist for more than 250 kyr after degassing ceases. Parametric analysis shows that brine lenses are more prevalent when the fluid is released at temperatures above the wet granite solidus, when magmatic fluid salinity is high, and when the high-permeability pathway is narrow. The calculated depth, form and electrical conductivity of our modelled system shares many features with published magnetotelluric images of volcano subsurfaces. The formation and persistence of sub-volcanic brine lenses has implications for geothermal systems and hydrothermal ore formation, although these features are not explored in the presented model.

  10. The lithosphere-asthenosphere boundary beneath the South Island of New Zealand

    Science.gov (United States)

    Hua, Junlin; Fischer, Karen M.; Savage, Martha K.

    2018-02-01

    Lithosphere-asthenosphere boundary (LAB) properties beneath the South Island of New Zealand have been imaged by Sp receiver function common-conversion point stacking. In this transpressional boundary between the Australian and Pacific plates, dextral offset on the Alpine fault and convergence have occurred for the past 20 My, with the Alpine fault now bounded by Australian plate subduction to the south and Pacific plate subduction to the north. Using data from onland seismometers, especially the 29 broadband stations of the New Zealand permanent seismic network (GeoNet), we obtained 24,971 individual receiver functions by extended-time multi-taper deconvolution, and mapped them to three-dimensional space using a Fresnel zone approximation. Pervasive strong positive Sp phases are observed in the LAB depth range indicated by surface wave tomography. These phases are interpreted as conversions from a velocity decrease across the LAB. In the central South Island, the LAB is observed to be deeper and broader to the northwest of the Alpine fault. The deeper LAB to the northwest of the Alpine fault is consistent with models in which oceanic lithosphere attached to the Australian plate was partially subducted, or models in which the Pacific lithosphere has been underthrust northwest past the Alpine fault. Further north, a zone of thin lithosphere with a strong and vertically localized LAB velocity gradient occurs to the northwest of the fault, juxtaposed against a region of anomalously weak LAB conversions to the southeast of the fault. This structure could be explained by lithospheric blocks with contrasting LAB properties that meet beneath the Alpine fault, or by the effects of Pacific plate subduction. The observed variations in LAB properties indicate strong modification of the LAB by the interplay of convergence and strike-slip deformation along and across this transpressional plate boundary.

  11. A Receiver Function Study of Mantle Transition Zone Discontinuities beneath Egypt and Saudi Arabia

    Science.gov (United States)

    Liu, K. H.; Mohamed, A. A.; Gao, S. S.; Elsheikh, A. A.; Yu, Y.; Fat-Helbary, R. E.

    2014-12-01

    The dramatic asymmetry in terms of surface elevation, Cenozoic volcanisms, and earthquake activity across the Red Sea is an enigmatic issue in global tectonics, partially due to the unavailability of broadband seismic data on the African plate adjacent to the Red Sea. Here we report the first results from a receiver function study of the mantle transition zone (MTZ) discontinuities using data from the Egyptian National Seismic Network, and compare the resulting depths of the 410 and 660 km discontinuities (d410 and d660) with those observed on the Arabian side. Results using more than 6000 P-to-S receiver functions recorded at 49 broadband seismic stations in Egypt, Saudi Arabia and adjacent areas show that when the IASP91 Earth model is used for time-to-depth conversion, the resulting depth of the discontinuities increases systematically toward the axis of the Afro-Arabian Dome (AAD) from both the west and east. Relative to the westernmost area, the maximum depression of the 410-km discontinuity is about 30 km, and that of the 660-km discontinuity is about 45 km. Highly correlated d410 and d660 depths suggest that the observed apparent depth variations are mostly caused by lateral velocity anomalies in the upper mantle, while the 15 km additional depression of the d660 relative to the d410 requires either a colder-than-normal MTZ or the presence of water in the MTZ. We tested several models involving upper mantle and MTZ velocity anomalies and undulations of the MTZ discontinuities due to temperature anomalies and water content, and found that the observed systematic variations can best be explained by a model involving a hydrated MTZ and an upper-mantle low-velocity zone beneath the AAD (Mohamed et al., 2014, doi: 10.1093/gji/ggu284). Models invoking one or more mantle plumes originated from the MTZ or the lower-mantle beneath the study area are not consistent with the observations.

  12. Helium as a tracer for fluids released from Juan de Fuca lithosphere beneath the Cascadia forearc

    Science.gov (United States)

    McCrory, Patricia A.; Constantz, James E.; Hunt, Andrew G.; Blair, James Luke

    2016-01-01

    The ratio between helium isotopes (3He/4He) provides an excellent geochemical tracer for investigating the sources of fluids sampled at the Earth's surface. 3He/4He values observed in 25 mineral springs and wells above the Cascadia forearc document a significant component of mantle-derived helium above Juan de Fuca lithosphere, as well as variability in 3He enrichment across the forearc. Sample sites arcward of the forearc mantle corner (FMC) generally yield significantly higher ratios (1.2-4.0 RA) than those seaward of the corner (0.03-0.7 RA). The highest ratios in the Cascadia forearc coincide with slab depths (40-45 km) where metamorphic dehydration of young oceanic lithosphere is expected to release significant fluid and where tectonic tremor occurs, whereas little fluid is expected to be released from the slab depths (25-30 km) beneath sites seaward of the corner.Tremor (considered a marker for high fluid pressure) and high RA values in the forearc are spatially correlated. The Cascadia tremor band is centered on its FMC, and we tentatively postulate that hydrated forearc mantle beneath Cascadia deflects a significant portion of slab-derived fluids updip along the subduction interface, to vent in the vicinity of its corner. Furthermore, high RA values within the tremor band just arcward of the FMC, suggest that the innermost mantle wedge is relatively permeable.Conceptual models require: (1) a deep fluid source as a medium to transport primordial 3He; (2) conduits through the lithosphere which serve to speed fluid ascent to the surface before significant dilution from radiogenic 4He can occur; and (3) near lithostatic fluid pressure to keep conduits open. Our spatial correlation between high RA values and tectonic tremor provides independent evidence that tremor is associated with deep fluids, and it further suggests that high pore pressures associated with tremor may serve to keep fractures open for 3He migration through ductile upper mantle and lower crust.

  13. Slab remnants beneath the Baja California peninsula: Seismic constraints and tectonic implications

    Science.gov (United States)

    Paulssen, Hanneke; de Vos, Denise

    2017-11-01

    The formation of the Gulf of California has been related to the cessation of subduction of the Guadalupe and Magdalena microplates. Various studies have identified features that point to the presence of a slab remnant beneath the Baja California peninsula, but its depth range and lateral extent remained unclear. In this study we used surface wave phase velocity and receiver function data of NARS-Baja stations around the Gulf of California to better constrain the location of the slab. For stations in central and southern Baja California the shear velocity models show an upper mantle high-velocity layer with its top in the depth range from 115 to 135km and a thickness varying between roughly 40 and 60km. These high-velocity anomalies are interpreted as subducted slab remnants. In contrast, the models for the northern peninsula show no slab signature. This change directly correlates with the variation in relative motion between the Baja California peninsula and the Pacific plate as measured by GPS data. It is inferred that the stalled slab fragments beneath the peninsula produce strong coupling between Baja California and the Pacific plate. The shear velocity models for stations on the Mexican mainland show a layer of higher velocities above a low-velocity upper mantle. In the North, the low-velocity mantle, starting at a depth of 40km, is associated with upwelling as suggested by previous studies. Further south, the transition from higher to lower mantle velocities occurs around 80km depth, which is a typical value for the lithosphere-asthenosphere boundary. Furthermore, the models show strong crustal thinning towards the gulf, both from the peninsula as well as from the Mexican mainland.

  14. Upper Mantle Shear Wave Structure Beneath North America From Multi-mode Surface Wave Tomography

    Science.gov (United States)

    Yoshizawa, K.; Ekström, G.

    2008-12-01

    The upper mantle structure beneath the North American continent has been investigated from measurements of multi-mode phase speeds of Love and Rayleigh waves. To estimate fundamental-mode and higher-mode phase speeds of surface waves from a single seismogram at regional distances, we have employed a method of nonlinear waveform fitting based on a direct model-parameter search using the neighbourhood algorithm (Yoshizawa & Kennett, 2002). The method of the waveform analysis has been fully automated by employing empirical quantitative measures for evaluating the accuracy/reliability of estimated multi-mode phase dispersion curves, and thus it is helpful in processing the dramatically increasing numbers of seismic data from the latest regional networks such as USArray. As a first step toward modeling the regional anisotropic shear-wave velocity structure of the North American upper mantle with extended vertical resolution, we have applied the method to long-period three-component records of seismic stations in North America, which mostly comprise the GSN and US regional networks as well as the permanent and transportable USArray stations distributed by the IRIS DMC. Preliminary multi-mode phase-speed models show large-scale patterns of isotropic heterogeneity, such as a strong velocity contrast between the western and central/eastern United States, which are consistent with the recent global and regional models (e.g., Marone, et al. 2007; Nettles & Dziewonski, 2008). We will also discuss radial anisotropy of shear wave speed beneath North America from multi-mode dispersion measurements of Love and Rayleigh waves.

  15. Fate and Transport of 17β-Estradiol beneath Animal Waste Holding Ponds.

    Science.gov (United States)

    Duncan, Lori A; Tyner, John S; Buchanan, John R; Hawkins, Shawn A; Lee, Jaehoon

    2015-05-01

    Concentrated animal feeding operations typically store livestock waste in clay-lined ponds. Although these ponds are regulated to include a liner with a small hydraulic conductivity to limit leaching, previous studies have traced surface and groundwater contamination from such regulated animal waste ponds. This research examined the transport of 17β-estradiol (E2) and its primary metabolite, estrone (E1), through soil liners using field- and laboratory-based studies. Additionally, a potential engineering solution to limit hormone transport-applying biochar to new pond liners to act as a retardant-was studied. Soil cores 80 cm in length were collected beneath a mature dairy waste pond and analyzed for moisture content and hormone concentrations. Unsaturated conditions and E2 concentrations of 4 to 250 ng g were detected beneath the waste pond. In the laboratory portion of the study, hand-packed columns of sand or clay were subjected to infiltration by a 2.3-m head of dairy waste. A subset of the hand-packed sand columns was amended with powdered biochar to test its ability to retard E2 and E1. For 3 mo, column leachate was analyzed for hormone concentrations, and at the conclusion of the study E2 and E1 concentrations in the soil were measured. In the 44 d after sealing, the clay, sand, sand with a thin layer of biochar, and sand mixed with a biochar amendment leached a total of 0.54, 1.3, 0.09, and 0.45 μg of E2, respectively. The biochar amendments to the hand-packed columns considerably minimized E2 in the leachate. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. Modeling Rayleigh Wave Azimuthal Anisotropy in the Upper Mantle Beneath Hawaii

    Science.gov (United States)

    Chojnacki, P. R.; Laske, G.

    2011-12-01

    We present results from the forward modeling of frequency-dependent Rayleigh wave azimuthal anisotropy observed at the Hawaiian Plume-Lithosphere Undersea Mantle Experiment (PLUME) that was deployed from January 2005 through May 2007. We create models of the mantle consisting of one or two layers of constant anisotropy derived from pyrolite, which has one symmetry axis, in order to understand how mantle flow affects observations of Rayleigh wave azimuthal anisotropy. We perform forward modeling experiments in which we vary the depth and thickness of the layer(s), as well as the inclination and azimuth of the symmetry axis in each of the layers. We use mode summation code MINOS to calculate predictions for these models. Then we compare the predictions with frequency-dependent average phase velocities within a series of station triangles. We use a chi-squared test for frequencies between 10 and 50 mHz to model the two principal parameters of azimuthal anisotropy: the frequency-dependent strength of azimuthal anisotropy and the frequency-dependent direction of fast phase velocity. For the former, we fix the azimuth in the synthetic model and compare the strength of anisotropy. For one-layer models, we find that most station triangles are best fit by fixing the inclination between 20 and 35° from the vertical, suggesting that a significant amount of vertical mineral alignment is present. Almost all station triangles require an anisotropic layer beginning no deeper than 50 km below the surface, and a thinner layer is present beneath the Island of Hawaii and to the east of the islands. A thicker layer is present beneath and to the west of the older islands. First results from two-layer modeling suggest that a layer in the asthenosphere must consist of near horizontal flow while a layer in the lithosphere must contain a significant amount of vertical anisotropy.

  17. Evidence for gas and magmatic sources beneath the Yellowstone volcanic field from seismic tomographic imaging

    Science.gov (United States)

    Husen, Stephan; Smith, Robert B.; Waite, Gregory P.

    2004-03-01

    The 3-D P-wave velocity and P- to S-wave velocity ratio structure of the Yellowstone volcanic field, Wyoming, has been determined from local earthquake tomography using new data from the permanent Yellowstone seismic network. We selected 3374 local earthquakes between 1995 and 2001 to invert for the 3-D P-wave velocity ( Vp) and P-wave to S-wave velocity ratio ( Vp/ Vs) structure. Vp anomalies of small size (15×15 km) are reliably imaged in the northwestern part of the model outside the Yellowstone caldera; inside the caldera only Vp anomalies of large size extending over several grid nodes are reliably imaged. The Vp/ Vs solution is generally poorer due to the low number of S-P arrival times. Only the northwestern part of the model is resolved with confidence; the Vp/ Vs solution also suffers from strong vertical and horizontal velocity smearing. The tomographic images confirm the existence of a low Vp-body beneath the Yellowstone caldera at depths greater than 8 km, possibly representing hot, crystallizing magma. The most striking result of our study is a volume of anomalously low Vp and Vp/ Vs in the northwestern part of the Yellowstone volcanic field at shallow depths of <2.0 km. Theoretical calculations of changes in P- to S-wave velocity ratios indicate that these anomalies can be interpreted as porous, gas-filled rock. The close spatial correlation of the observed anomalies and the occurrence of the largest earthquake swarm in historic time in Yellowstone, 1985, suggest that the gas may have originated as part of magmatic fluids released by crystallization of magma beneath the Yellowstone caldera.

  18. Drought-induced recharge promotes long-term storage of porewater salinity beneath a prairie wetland

    Science.gov (United States)

    Levy, Zeno F.; Rosenberry, Donald O.; Moucha, Robert; Mushet, David M.; Goldhaber, Martin B.; LaBaugh, James W.; Fiorentino, Anthony J.; Siegel, Donald I.

    2018-02-01

    Subsurface storage of sulfate salts allows closed-basin wetlands in the semiarid Prairie Pothole Region (PPR) of North America to maintain moderate surface water salinity (total dissolved solids [TDS] from 1 to 10 g L-1), which provides critical habitat for communities of aquatic biota. However, it is unclear how the salinity of wetland ponds will respond to a recent shift in mid-continental climate to wetter conditions. To understand better the mechanisms that control surface-subsurface salinity exchanges during regional dry-wet climate cycles, we made a detailed geoelectrical study of a closed-basin prairie wetland (P1 in the Cottonwood Lake Study Area, North Dakota) that is currently experiencing record wet conditions. We found saline lenses of sulfate-rich porewater (TDS > 10 g L-1) contained in fine-grained wetland sediments 2-4 m beneath the bathymetric low of the wetland and within the currently ponded area along the shoreline of a prior pond stand (c. 1983). During the most recent drought (1988-1993), the wetland switched from a groundwater discharge to recharge function, allowing salts dissolved in surface runoff to move into wetland sediments beneath the bathymetric low of the basin. However, groundwater levels during this time did not decline to the elevation of the saline lenses, suggesting these features formed during more extended paleo-droughts and are stable in the subsurface on at least centennial timescales. We hypothesize a "drought-induced recharge" mechanism that allows wetland ponds to maintain moderate salinity under semiarid climate. Discharge of drought-derived saline groundwater has the potential to increase the salinity of wetland ponds during wet climate.

  19. The preliminary results: Internal seismic velocity structure imaging beneath Mount Lokon

    Energy Technology Data Exchange (ETDEWEB)

    Firmansyah, Rizky, E-mail: rizkyfirmansyah@hotmail.com [Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, 40132 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysical Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, 40132 (Indonesia); Kristianto, E-mail: kris@vsi.esdm.go.id [Center for Volcanology and Geological Hazard Mitigation (CVGHM), Geological Agency, Bandung, 40122 (Indonesia)

    2015-04-24

    Historical records that before the 17{sup th} century, Mount Lokon had been dormant for approximately 400 years. In the years between 1350 and 1400, eruption ever recorded in Empung, came from Mount Lokon’s central crater. Subsequently, in 1750 to 1800, Mount Lokon continued to erupt again and caused soil damage and fall victim. After 1949, Mount Lokon dramatically increased in its frequency: the eruption interval varies between 1 – 5 years, with an average interval of 3 years and a rest interval ranged from 8 – 64 years. Then, on June 26{sup th}, 2011, standby alert set by the Center for Volcanology and Geological Hazard Mitigation. Peak activity happened on July 4{sup th}, 2011 that Mount Lokon erupted continuously until August 28{sup th}, 2011. In this study, we carefully analyzed micro-earthquakes waveform and determined hypocenter location of those events. We then conducted travel time seismic tomographic inversion using SIMULPS12 method to detemine Vp, Vs and Vp/Vs ratio structures beneath Lokon volcano in order to enhance our subsurface geological structure. During the tomographic inversion, we started from 1-D seismic velocities model obtained from VELEST33 method. Our preliminary results show low Vp, low Vs, and high Vp/Vs are observed beneath Mount Lokon-Empung which are may be associated with weak zone or hot material zones. However, in this study we used few station for recording of micro-earthquake events. So, we suggest in the future tomography study, the adding of some seismometers in order to improve ray coverage in the region is profoundly justified.

  20. Microleakage beneath ceramic and metal brackets photopolymerized with LED or conventional light curing units.

    Science.gov (United States)

    Arikan, Serdar; Arhun, Neslihan; Arman, Ayça; Cehreli, Sevi Burcak

    2006-11-01

    To test the null hypotheses that (1) the type of light curing unit used (quartz-tungsten-halogen [QTH] or light-emitting diode [LED]) would not affect the amount of microleakage observed beneath brackets, and (2) the bracket type used (ceramic or metal) would not influence the amount of microleakage observed beneath brackets. 40 freshly-extracted human premolars were randomly assigned into 4 bonding groups (n = 10/group): group 1, metal bracket + LED-cured Transbond XT; group 2, ceramic bracket + LED-cured Transbond XT; group 3, metal bracket + QTH-cured Transbond XT; and group 4, ceramic bracket + QTH-cured Transbond XT. The teeth were kept in distilled water for 1 month, and thereafter subjected to 500 thermal cycles. Then, specimens were sealed with nail varnish, stained with 0.5% basic fuchsin for 24 hours, sectioned, and photographed under a stereomicroscope. Microleakage was scored with regard to the adhesive-tooth interface and the bracket-adhesive interface at both incisal and gingival margins. Statistical analysis was accomplished by Kruskal-Wallis and Mann-Whitney U-tests with Bonferroni correction. Microleakage was observed in all groups. When an LED curing unit was used for adhesive polymerization, ceramic brackets displayed significantly less microleakage than metal brackets in both tooth-adhesive and bracket-adhesive interfaces. When a QTH curing unit was used, ceramic brackets displayed significantly less microleakage than metal brackets in the bracket-adhesive interface in both gingival and incisal margins. Ceramic brackets cured with LED units were the best combination, demonstrating the lowest microleakage scores.

  1. Compositions and processes of lithospheric mantle beneath the west Cathaysia block, southeast China

    Science.gov (United States)

    Zhang, Hui; Zheng, Jianping; Pan, Shaokui; Lu, Jianggu; Li, Yihe; Xiang, Lu; Lin, Abing

    2017-08-01

    Knowledge about the nature and history of the lithospheric mantle beneath the west Cathaysia block (South China) is still sparse. The major- and trace-element compositions and H2O contents of minerals from peridotite xenoliths entrained in the Cenozoic lamprophyres of the Anyuan area (SE China), were conducted to investigate the nature and evolution of the lithospheric mantle, as well as the factors controlling the distribution of water. The xenoliths including spinel harzburgites and lherzolites are moderately refractory (Mg# Olivine = 90.2-91.2) with minor fertile lherzolites (Mg# Olivine = 89.1-89.9). Clinopyroxenes in lherzolites show variable REE patterns from LREE-depleted to LREE-enriched patterns, and commonly exhibit negative anomalies of U, Pb and Ti. The mantle represented by the xenoliths mostly experienced 1-10% partial melting and obvious subsequent silicate metasomatism. H2O contents of clinopyroxene, orthopyroxene, and olivine in the peridotites are 320-404 ppm, 138-200 ppm, and 11-33 ppm, respectively. The whole-rock H2O contents range from 63 to 120 ppm, similar to that estimated for the MORB source. The negative correlations of H2O contents with Mg# in olivine and lack of correlation correlations with (La/Yb)N in clinopyroxene suggest that the H2O contents are mainly controlled by the partial melting process rather than mantle metasomatism. The fertile and moderately refractory peridotite xenoliths have similar equilibrium temperatures, implying that the lithospheric mantle is not compositionally stratified. Integrated with published data, we suggest that the widespread fertile and moderately refractory lithospheric mantle beneath the studied area (west Cathaysia), even the whole South China, might be eroded or melt-rock reacted by upwelling asthenospheric materials. Finally, the cooling of the upwelled asthenospheric materials resulted in the formation of the accreted lithospheric mantle mixed with pre-existing moderately refractory volumes.

  2. Crust beneath the northwestern Deccan Volcanic Province, India: Evidence for uplift and magmatic underplating

    Science.gov (United States)

    Rao, K. Madhusudhan; Kumar, M. Ravi; Rastogi, B. K.

    2015-05-01

    The northwestern Deccan Volcanic Province of India and its pericratonic rift basins were reactivated during different stages after the breakup of India from the Gondwanaland and collision with the Asian plate. In this study, we present results of crustal thickness and average crustal Vp/Vs ratios beneath this plume-affected region using common conversion point imaging and H-k stacking analysis of 6893 receiver functions using data from a network comprising 58 broadband seismic stations sited on diverse tectonic terrains. We find large variations in crustal thickness, with the Moho depths varying from 28 to 43 km in the Kachchh rift, 28 to 38 km in the Cambay rift, 39.5-41.5 km in the north and eastern parts of the Cambay rift, and 29 to 39 km in the Saurashtra region and South Gujarat. A Moho upwarp of 6 to 7 km in the Saurashtra region can be attributed to positive buoyancy and uplift due to thermal influx affected by the Reunion plume. High crustal Vp/Vs ratios beneath the Kachchh rift (1.8 to 2.05), coastal areas of Saurashtra (1.75 to 2.06), and North Gujarat (1.81 to 1.85) indicate dominance of a mafic/ultramafic crust. High regional heat flow, high electrical conductivity, large intracrustal S wave velocity reduction, and high average crustal Poisson's ratios are consistent with partial melt related to the process of magmatic underplating in the lower crust. At other stations, the crust appears to be felsic with Vp/Vs ratios in the range of 1.57 to 1.76.

  3. Two Plumes Beneath the East African Rift System: a Geochemical Investigation into Possible Interactions in Ethiopia

    Science.gov (United States)

    Nelson, W. R.; Furman, T.; van Keken, P. E.; Lin, S.

    2007-12-01

    East African Rift System magmatism began over 40 my ago and has continued through the present. Numerical models have determined two plumes are necessary to create the spatial and temporal distribution of volcanism. Geochemical data support the presence of two chemically distinct plumes initially located beneath the Afar Depression (NE Ethiopia) and the Turkana Depression (SW Ethiopia/N Kenya). The timing and eruptive of the Afar and Kenya plumes are also distinct. While there is growing evidence to support the existence of two dynamically and chemically distinct plumes beneath the East African Rift System, the interactions between them remain unclear. Our study focuses on the geochemistry of mafic shield lavas from three locations on the eastern flank of the Ethiopian plateau. These lavas are spatially located between the surface manifestation of the Afar and Kenya plumes. The majority of the lava is alkaline and has experienced varying degrees of olivine and pyroxene fractionation. The northernmost lavas (9°10'N) are transitional and display the most fractionation. Primitive mantle melts were generated at depths near the fertile mantle garnet-spinel transition zone and deeper (80-100km) and are free of metasomatic influence. Minor HREE depletions also support derivation of melts from a garnet-bearing source. Lavas with lithospheric influence are generated from shallower depths and show minor amphibole influence. Overall, geochemical data show the lavas in this study closely resemble those from various episodes of Kenya plume magmatism with modifications attributed to lithospheric contamination. This interpretation is consistent with current numerical models suggesting episodic northward movement of Kenya plume magmas along the lithosphere-asthenosphere boundary. The data imply that the Kenya plume has a much larger spatial influence and therefore a larger geodynamic influence in the EARS than previously recognized.

  4. A First Crustal Model beneath Portugal from Teleseismic Rayleigh Wave Ellipticity Inversion

    Science.gov (United States)

    Attanayake, Januka; Ferreira, Ana M. G.; Berbellini, Andrea; Morelli, Andrea

    2017-04-01

    Accurate seismic crustal models are important for interpreting seismicity and tectonics and predicting strong ground motion. These interpretations and predictions are particularly important in regions prone to significant seismic hazard such as Portugal, where considerable destruction has taken place from large on- and offshore earthquakes (e.g. 1755 M 8 Lisbon and 1909 Benavente M 6.0 earthquakes). The lack of high quality countrywide broadband data in the past has hindered quantitative characterization of regional Earth structure in Portugal. Due to a significant expansion of the Portuguese seismic network, however, a large volume of data is accumulating since 2006. We used this new high quality dataset to measure multi-period Rayleigh Wave Ellipticity (RWE), which we inverted to build the first seismic crustal model beneath Portugal. RWE is defined by the Horizontal-to-Vertical (H/V) amplitude ratio at a given seismic station, and theoretical studies demonstrate it to be strongly sensitive to the structure immediately beneath that particular station. We measured teleseismic RWE between 15 s and 60 s from 33 permanent and temporary stations in Portugal and inverted it for shear wave velocity (Vs) structure of the crust using a fully non-linear Monte Carlo method. Our results show that both RWE and Vs are spatially correlated with surface geology. Notably, sedimentary basins produced by Mesozoic rifting (e.g. Lusitanian Basin (LB) and the Lower Tagus-Sado Basin (LTSB)) are correlated with higher RWE (lower Vs). Similar high RWE values are observed in the interior of Central Iberian Zone (CIZ), which is an older metamorphic belt. We interpret this to be the signature of an extensional episode that the CIZ has undergone possibly simultaneous to the Mesozoic rift event. The Galicia-Tras-os-Montes-Zone (GTMZ)- a Paleozoic metamorphic belt - in Northern Portugal exhibits the lowest RWE (highest Vs), whereas other metamorphic terrains have RWE intermediate to Basins and

  5. Perception of audiovisual speech synchrony for native and non-native language.

    Science.gov (United States)

    Navarra, Jordi; Alsius, Agnès; Velasco, Ignacio; Soto-Faraco, Salvador; Spence, Charles

    2010-04-06

    To what extent does our prior experience with the correspondence between audiovisual stimuli influence how we subsequently bind them? We addressed this question by testing English and Spanish speakers (having little prior experience of Spanish and English, respectively) on a crossmodal simultaneity judgment (SJ) task with English or Spanish spoken sentences. The results revealed that the visual speech stream had to lead the auditory speech stream by a significantly larger interval in the participants' native language than in the non-native language for simultaneity to be perceived. Critically, the difference in temporal processing between perceiving native vs. non-native language tends to disappear as the amount of experience with the non-native language increases. We propose that this modulation of multisensory temporal processing as a function of prior experience is a consequence of the constraining role that visual information plays in the temporal alignment of audiovisual speech signals. Copyright 2010 Elsevier B.V. All rights reserved.

  6. Decoding speech perception by native and non-native speakers using single-trial electrophysiological data.

    Directory of Open Access Journals (Sweden)

    Alex Brandmeyer

    Full Text Available Brain-computer interfaces (BCIs are systems that use real-time analysis of neuroimaging data to determine the mental state of their user for purposes such as providing neurofeedback. Here, we investigate the feasibility of a BCI based on speech perception. Multivariate pattern classification methods were applied to single-trial EEG data collected during speech perception by native and non-native speakers. Two principal questions were asked: 1 Can differences in the perceived categories of pairs of phonemes be decoded at the single-trial level? 2 Can these same categorical differences be decoded across participants, within or between native-language groups? Results indicated that classification performance progressively increased with respect to the categorical status (within, boundary or across of the stimulus contrast, and was also influenced by the native language of individual participants. Classifier performance showed strong relationships with traditional event-related potential measures and behavioral responses. The results of the cross-participant analysis indicated an overall increase in average classifier performance when trained on data from all participants (native and non-native. A second cross-participant classifier trained only on data from native speakers led to an overall improvement in performance for native speakers, but a reduction in performance for non-native speakers. We also found that the native language of a given participant could be decoded on the basis of EEG data with accuracy above 80%. These results indicate that electrophysiological responses underlying speech perception can be decoded at the single-trial level, and that decoding performance systematically reflects graded changes in the responses related to the phonological status of the stimuli. This approach could be used in extensions of the BCI paradigm to support perceptual learning during second language acquisition.

  7. Exploring Native American Students' Perceptions of Scientists

    Science.gov (United States)

    Laubach, Timothy A.; Crofford, Geary Don; Marek, Edmund A.

    2012-07-01

    The purpose of this descriptive study was to explore Native American (NA) students' perceptions of scientists by using the Draw-A-Scientist Test and to determine if differences in these perceptions exist between grade level, gender, and level of cultural tradition. Data were collected for students in Grades 9-12 within a NA grant off-reservation boarding school. A total of 133 NA students were asked to draw a picture of a scientist at work and to provide a written explanation as to what the scientist was doing. A content analysis of the drawings indicated that the level of stereotype differed between all NA subgroups, but analysis of variance revealed that these differences were not significant between groups except for students who practised native cultural tradition at home compared to students who did not practise native cultural tradition at home (p stereotypes.

  8. Native Mutant Huntingtin in Human Brain

    Science.gov (United States)

    Sapp, Ellen; Valencia, Antonio; Li, Xueyi; Aronin, Neil; Kegel, Kimberly B.; Vonsattel, Jean-Paul; Young, Anne B.; Wexler, Nancy; DiFiglia, Marian

    2012-01-01

    Huntington disease (HD) is caused by polyglutamine expansion in the N terminus of huntingtin (htt). Analysis of human postmortem brain lysates by SDS-PAGE and Western blot reveals htt as full-length and fragmented. Here we used Blue Native PAGE (BNP) and Western blots to study native htt in human postmortem brain. Antisera against htt detected a single band broadly migrating at 575–850 kDa in control brain and at 650–885 kDa in heterozygous and Venezuelan homozygous HD brains. Anti-polyglutamine antisera detected full-length mutant htt in HD brain. There was little htt cleavage even if lysates were pretreated with trypsin, indicating a property of native htt to resist protease cleavage. A soluble mutant htt fragment of about 180 kDa was detected with anti-htt antibody Ab1 (htt-(1–17)) and increased when lysates were treated with denaturants (SDS, 8 m urea, DTT, or trypsin) before BNP. Wild-type htt was more resistant to denaturants. Based on migration of in vitro translated htt fragments, the 180-kDa segment terminated ≈htt 670–880 amino acids. If second dimension SDS-PAGE followed BNP, the 180-kDa mutant htt was absent, and 43–50 kDa htt fragments appeared. Brain lysates from two HD mouse models expressed native full-length htt; a mutant fragment formed if lysates were pretreated with 8 m urea + DTT. Native full-length mutant htt in embryonic HD140Q/140Q mouse primary neurons was intact during cell death and when cell lysates were exposed to denaturants before BNP. Thus, native mutant htt occurs in brain and primary neurons as a soluble full-length monomer. PMID:22375012

  9. Native Darag Chicken Menu Variations: Its Acceptability

    Directory of Open Access Journals (Sweden)

    Dr. Rosario Clarabel C. Contreras

    2014-06-01

    Full Text Available Traditional native chicken delicacies like lechon and adobo are very common dishes in a rural Filipino folks’ dining table. As the family economic standing improves, meat becomes a main item in a family diet, dishes like fried chicken and chicken nuggets have also become part of the family choices of chicken dishes in their meal. Intensification of the production of native Darag chicken would lead to optimization of food technological output for the university which will hopefully be a potential one town-one product (OTOP of the municipality.

  10. Coupled Geochemical and Hydrological Processes Governing the Fate and Transport of Radionuclides and Toxic Metals Beneath the Hanford Tank Farms

    Energy Technology Data Exchange (ETDEWEB)

    Scott Fendorf; Phil Jardine

    2006-07-21

    The goal of this research was to provide an improved understanding and predictive capability of coupled hydrological and geochemical mechanisms that are responsible for the accelerated migration and immobilization of radionuclides and toxic metals in the badose zone beneath the Hanford Tank Farms.

  11. What Lies beneath Seemingly Positive Campus Climate Results: Institutional Sexism, Racism, and Male Hostility toward Equity Initiatives and Liberal Bias

    Science.gov (United States)

    Vaccaro, Annemarie

    2010-01-01

    This article presents qualitative results from a campus climate study at one predominately white university. Data analysis uncovered "what lies beneath" a seemingly positive campus climate. Gender differences in survey responses suggest that men and women experienced the climate in vastly different ways. Additionally, lack of deep diversity…

  12. Low-velocity zones in the crust beneath Aso caldera, Kyushu, Japan, derived from receiver function analyses

    Science.gov (United States)

    Abe, Yuki; Ohkura, Takahiro; Shibutani, Takuo; Hirahara, Kazuro; Yoshikawa, Shin; Inoue, Hiroyuki

    2017-03-01

    Aso volcano, in central Kyushu Island in southwest Japan, has a large caldera (18 × 25 km) that formed by the ejection of more than 600 km3 of deposits 89 thousand years ago. We calculated receiver functions from teleseismic waveform data obtained from densely distributed stations in and around the caldera. We estimated the crustal S wave velocity structure from the receiver functions by using genetic algorithm inversion. We detected a low-velocity zone (Vs > 2.2 km/s) at a depth of 8-15 km beneath the eastern flank of the central cones. A sill-like deformation source has been detected at a depth of 15.5 km by analyses of GPS data, and a swarm of low-frequency earthquakes exists at depths of 15-25 km just beneath this low-velocity zone. Magma may be newly generated and accumulated in this low-velocity zone as a result of hot intrusions coming from beneath it. Except for the region beneath the eastern flank of the central cones, a second low-velocity zone (Vs > 1.9 km/s) extends in and around the caldera at a depth of 15-23 km, although phenomena representing intrusions have not been detected below it. From the estimated velocity structure, these low-velocity zones are interpreted to contain a maximum of 15% melt or 30% water.

  13. Complex structure of the lithospheric slab beneath the Banda arc, eastern Indonesia depicted by a seismic tomographic model

    Directory of Open Access Journals (Sweden)

    Sri Widiyantoro

    2011-10-01

    Full Text Available Seismic tomography with a non-linear approach has been successfully applied to image the P-wave velocity structure beneath the Banda arc in detail. Nearly one million compressional phases including the surfacereflected depth phases pP and pwP from events within the Indonesian region have been used. The depth phases have been incorporated in order to improve the sampling of the uppermantle structure, particularly below the Banda Sea in the back-arc regions. For the model parameterization, we have combined a highresolution regional inversion with a low-resolution global inversion to allow detailed images of slab structures within the study region and to minimize the mapping of distant aspherical mantle structure into the volume under study. In this paper, we focus our discussion on the upper mantle and transition zone structure beneath the curved Banda arc. The tomographic images confirm previous observations of the twisting of the slab in the upper mantle, forming a spoon-shaped structure beneath the Banda arc. A slab lying flat on the 660 km discontinuity beneath the Banda Sea is also well imaged. Further interpretations of the resulting tomograms and seismicity data support the scenario of the Banda arc subduction rollback.

  14. MPI Profiling

    Energy Technology Data Exchange (ETDEWEB)

    Han, D K; Jones, T R

    2005-02-11

    The Message Passing Interface (MPI) is the de facto message-passing standard for massively parallel programs. It is often the case that application performance is a crucial factor, especially for solving grand challenge problems. While there have been many studies on the scalability of applications, there have not been many focusing on the specific types of MPI calls being made and their impact on application performance. Using a profiling tool called mpiP, a large spectrum of parallel scientific applications were surveyed and their performance results analyzed.

  15. Proficient beyond borders: assessing non-native speakers in a native speakers’ framework

    Directory of Open Access Journals (Sweden)

    Johanna Fleckenstein

    2016-11-01

    Full Text Available Abstract Background English language proficiency is considered a basic skill that students from different language backgrounds are expected to master, independent of whether they are native or non-native speakers. Tests that measure language proficiency in non-native speakers are typically linked to the common European framework of reference for languages. Such tests, however, often lack the criteria to define a practically relevant degree of proficiency in English. We approach this deficit by assessing non-native speakers’ performance within a native speakers’ framework. Method Items from two English reading assessments—the Programme for International Student Assessment (PISA and the National Assessment (NA for English as a foreign language in Germany—were administered to N = 427 German high school students. Student abilities were estimated by drawing plausible values in a two-dimensional Rasch model. Results Results show that non-native speakers of English generally underperformed compared to native speakers. However, academic track students in the German school system achieved satisfactory levels of proficiency on the PISA scale. Linking the two scales showed systematic differences in the proficiency level classifications. Conclusion The findings contribute to the validation and international localization of NA standards for English as a foreign language. Practical implications are discussed with respect to policy-defined benchmarks for the successful participation in a global English-speaking society.

  16. Ethnic identity, drinking motives, and alcohol consequences among Alaska Native and non-Native college students.

    Science.gov (United States)

    Skewes, Monica C; Blume, Arthur W

    2015-01-01

    This research involves the examination of drinking motives, alcohol consequences, and ethnic identity in a sample of Native and non-Native college student drinkers in Alaska. Although more Alaska Native students are abstinent from alcohol compared to any other ethnic group, Native students who do drink experience greater alcohol consequences and dependence symptoms. Therefore, we attempted to examine the influence of ethnic identity on alcohol consequences in a diverse sample of Native and non-Native students in Alaska. Findings showed that drinking motives, as measured by the Drinking Motives Questionnaire (social, coping, enhancement, and conformity), significantly predicted alcohol consequences after controlling for frequency of monthly binge drinking. In addition, after controlling for depression, binge drinking, and drinking motives, one aspect of ethnic identity (Affirmation, Belonging, and Commitment) was significantly negatively related to alcohol consequences, whereas another aspect of ethnic identity (Ethnic Identity Search) was not. Taken together, these findings suggest that interventions for college student alcohol misuse that target Native students should be culturally grounded and focused on enhancing the Affirmation, Belonging, and Commitment to one's ethnic heritage and should address drinking motives, especially drinking to cope, as a way to reduce alcohol related harm.

  17. Patient Portal Integration - A Native IHE Connector Implementation for PEHR.

    Science.gov (United States)

    Yüksekogul, Nilay; Schreiweis, Björn; Weiss, Nicolas; Aguduri, Lakshmi S; Brandner, Antje; Bronsch, Tobias; Pensold, Peter; Stein, Katharina E; Helmer, Axel; Bergh, Björn; Heinze, Oliver

    2016-01-01

    Providing patients with access to their medical data has recently evolved as a topic in several countries. Different approaches are possible. For example patient portals are used for patient access towards medical data. The University Hospital Heidelberg is engaged in a research project to develop a personal cross-enterprise electronic health record (PEHR). The objective of this work is to describe the architecture and implementation of a component called IHE Connector which represents the native IHE-based integration between the patient portal and the PEHR core components. The architecture of the PEHR is accepted based on international standards. The core components consist out of ready to use software products like a master patient index. The patient portal has been developed using Liferay framework. The IHE Connector is mainly based on the Open eHealth Integration Platform (IPF) Framework, which has been deeply integrated into the patient portal to support the needed IHE transactions. Several IHE profiles for sharing documents and patient information are supported by the IHE Connector. As IPF already provides interfaces for some IHE profiles others had to be developed from scratch. The IHE Connector can not only be used for connectivity between patient portal and PEHR core, but also provide connectivity for third party apps and healthcare providers' information systems.

  18. Radial, Viscous, Saffman-Taylor Fingering of Hot Asthenosphere associated with the Icelandic plume beneath the North Atlantic Ocean

    Science.gov (United States)

    White, Nicky; Schoonman, Charlotte

    2017-04-01

    The Icelandic plume has had a significant influence upon the geologic and oceanographic evolution of the North Atlantic Ocean throughout Cenozoic times. Published full-waveform earthquake tomographic imaging of this region shows that the planform of this plume has a complex irregular shape with significant shear wave velocity anomalies lying beneath the lithospheric plate at depths of between 100 and 200 km. The planform of these anomalies suggests that five or more horizontal fingers extend radially beneath the fringing continental margins. The best-resolved of these fingers lie beneath the British Isles and beneath western Norway where significant crustal isostatic departures have been measured. Here, we propose that these radial fingers are generated by a well-known fluid dynamical phenomenon known as the Saffman-Taylor instability. Experimental and theoretical analyses show that radial, miscible viscous fingering occurs when a less viscous fluid is injected into a more viscous fluid. The wavelength and number of fingers are controlled by the mobility (i.e. the ratio of viscosities), by the Peclet number (i.e. the ratio of advective and diffusive processes), and by the thickness of the horizontal layer into which fluid is injected. We have combined shear wave velocity estimates with residual depth measurements around the Atlantic margins to calculate the planform distribution of temperature and viscosity within an asthenospheric layer beneath the lithospheric plates. Our calculations suggest that the mobility is 20-50, that the Peclet number is O(10000), and that the asthenospheric channel is 150 +/- 50 km thick. The existence and form of viscous fingering is consistent with experimental observations and with linear stability analysis. A useful rule of thumb is that the wavelength of viscous fingering is 5 +/- 1 times the thickness of the horizontal layer. Our proposal support the notion that dynamic topography of the Earth's surface can be generated and

  19. Seismological evidence for monsoon induced micro to moderate earthquake sequence beneath the 2011 Talala, Saurashtra earthquake, Gujarat, India

    Science.gov (United States)

    Singh, A. P.; Mishra, O. P.

    2015-10-01

    In order to understand the processes involved in the genesis of monsoon induced micro to moderate earthquakes after heavy rainfall during the Indian summer monsoon period beneath the 2011 Talala, Saurashtra earthquake (Mw 5.1) source zone, we assimilated 3-D microstructures of the sub-surface rock materials using a data set recorded by the Seismic Network of Gujarat (SeisNetG), India. Crack attributes in terms of crack density (ε), the saturation rate (ξ) and porosity parameter (ψ) were determined from the estimated 3-D sub-surface velocities (Vp, Vs) and Poisson's ratio (σ) structures of the area at varying depths. We distinctly imaged high-ε, high-ξ and low-ψ anomalies at shallow depths, extending up to 9-15 km. We infer that the existence of sub-surface fractured rock matrix connected to the surface from the source zone may have contributed to the changes in differential strain deep down to the crust due to the infiltration of rainwater, which in turn induced micro to moderate earthquake sequence beneath Talala source zone. Infiltration of rainwater during the Indian summer monsoon might have hastened the failure of the rock by perturbing the crustal volume strain of the causative source rock matrix associated with the changes in the seismic moment release beneath the surface. Analyses of crack attributes suggest that the fractured volume of the rock matrix with high porosity and lowered seismic strength beneath the source zone might have considerable influence on the style of fault displacements due to seismo-hydraulic fluid flows. Localized zone of micro-cracks diagnosed within the causative rock matrix connected to the water table and their association with shallow crustal faults might have acted as a conduit for infiltrating the precipitation down to the shallow crustal layers following the fault suction mechanism of pore pressure diffusion, triggering the monsoon induced earthquake sequence beneath the source zone.

  20. Crustal structure beneath the High Lava Plains of eastern Oregon and surrounding regions from receiver function analysis

    Science.gov (United States)

    Eagar, Kevin C.; Fouch, Matthew J.; James, David E.; Carlson, Richard W.

    2011-02-01

    We analyze teleseismic P-to-S receiver functions to image crustal structure beneath the High Lava Plains (HLP) of eastern Oregon and surrounding regions. Coverage from 206 broadband seismic stations provides the first opportunity to resolve variations in crustal composition, thickness, and heterogeneity on scales of a few km in depth and tens of km laterally across the HLP region. We utilize both H - κ stacking and a new Gaussian-weighted common conversion point stacking technique. We find crust that is ≥40 km thick beneath the Cascades, Idaho Batholith, and Owyhee Plateau and thinner (˜31 km) crust beneath the HLP and northern Great Basin. Low Poisson's ratios of ˜0.240 characterize the granitic crust beneath the Idaho Batholith, while the Owyhee Plateau exhibits values of ˜0.270, typical of average continental crust. The Owyhee Plateau is a thick simple crustal block with distinct edges at depth. The western HLP exhibits high average values of 0.304, typical for regions of widespread basaltic volcanism. Combined with other geological and geophysical observations, the areas of abnormally high Poisson's ratios (˜0.320) and low-velocity zones in the crust beneath north-central and southern Oregon are consistent with the presence of partial melt on either side of the HLP trend, suggesting a central zone where crustal melts have drained to the surface, perhaps enabled by the Brothers Fault Zone. Thicker crust and an anomalous N-S band of low Poisson's ratios (˜0.252) skirting the Steens Mountain escarpment is consistent with residuum from a midcrustal magma source of the massive flood basalts, supporting the view of extensive mafic underplating and intraplating of the crust from Cenozoic volcanism.

  1. Crustal structure beneath the Blue Mountains terranes and cratonic North America, eastern Oregon, and Idaho, from teleseismic receiver functions

    Science.gov (United States)

    Christian Stanciu, A.; Russo, Raymond M.; Mocanu, Victor I.; Bremner, Paul M.; Hongsresawat, Sutatcha; Torpey, Megan E.; VanDecar, John C.; Foster, David A.; Hole, John A.

    2016-07-01

    We present new images of lithospheric structure obtained from P-to-S conversions defined by receiver functions at the 85 broadband seismic stations of the EarthScope IDaho-ORegon experiment. We resolve the crustal thickness beneath the Blue Mountains province and the former western margin of cratonic North America, the geometry of the western Idaho shear zone (WISZ), and the boundary between the Grouse Creek and Farmington provinces. We calculated P-to-S receiver functions using the iterative time domain deconvolution method, and we used the H-k grid search method and common conversion point stacking to image the lithospheric structure. Moho depths beneath the Blue Mountains terranes range from 24 to 34 km, whereas the crust is 32-40 km thick beneath the Idaho batholith and the regions of extended crust of east-central Idaho. The Blue Mountains group Olds Ferry terrane is characterized by the thinnest crust in the study area, 24 km thick. There is a clear break in the continuity of the Moho across the WISZ, with depths increasing from 28 km west of the shear zone to 36 km just east of its surface expression. The presence of a strong midcrustal converting interface at 18 km depth beneath the Idaho batholith extending 20 km east of the WISZ indicates tectonic wedging in this region. A north striking 7 km offset in Moho depth, thinning to the east, is present beneath the Lost River Range and Pahsimeroi Valley; we identify this sharp offset as the boundary that juxtaposes the Archean Grouse Creek block with the Paleoproterozoic Farmington zone.

  2. DOBRE-2 WARR profile

    DEFF Research Database (Denmark)

    Starostenko, V.; Janik, T.; Stephenson, R.

    2016-01-01

    zone in the southern part of the Azov Sea. A broader and somewhat deeper basement unit (about 11 km) with an antiformal shape lies beneath the northern East Black Sea Basin and forms the southern margin of the Crimea–Caucasus compressional zone. The depth of the underlying Moho discontinuity increases...

  3. The vowel inherent spectral change of English vowels spoken by native and non-native speakers.

    Science.gov (United States)

    Jin, Su-Hyun; Liu, Chang

    2013-05-01

    The current study examined Vowel Inherent Spectral Change (VISC) of English vowels spoken by English-, Chinese-, and Korean-native speakers. Two metrics, spectral distance (amount of spectral shift) and spectral angle (direction of spectral shift) of formant movement from the onset to the offset, were measured for 12 English monophthongs produced in a /hvd/ context. While Chinese speakers showed significantly greater spectral distances of vowels than English and Korean speakers, there was no significant speakers' native language effect on spectral angles. Comparisons to their native vowels for Chinese and Korean speakers suggest that VISC might be affected by language-specific phonological structure.

  4. Germination and growth of native and invasive plants on soil associated with biological control of tamarisk (Tamarix spp.)

    Science.gov (United States)

    Sherry, Rebecca A.; Shafroth, Patrick B.; Belnap, Jayne; Ostoja, Steven M.; Reed, Sasha C.

    2016-01-01

    Introductions of biocontrol beetles (tamarisk beetles) are causing dieback of exotic tamarisk in riparian zones across the western United States, yet factors that determine plant communities that follow tamarisk dieback are poorly understood. Tamarisk-dominated soils are generally higher in nutrients, organic matter, and salts than nearby soils, and these soil attributes might influence the trajectory of community change. To assess physical and chemical drivers of plant colonization after beetle-induced tamarisk dieback, we conducted separate germination and growth experiments using soil and litter collected beneath defoliated tamarisk trees. Focal species were two common native (red threeawn, sand dropseed) and two common invasive exotic plants (Russian knapweed, downy brome), planted alone and in combination. Nutrient, salinity, wood chip, and litter manipulations examined how tamarisk litter affects the growth of other species in a context of riparian zone management. Tamarisk litter, tamarisk litter leachate, and fertilization with inorganic nutrients increased growth in all species, but the effect was larger on the exotic plants. Salinity of 4 dS m−1 benefitted Russian knapweed, which also showed the largest positive responses to added nutrients. Litter and wood chips generally delayed and decreased germination; however, a thinner layer of wood chips increased growth slightly. Time to germination was lengthened by most treatments for natives, was not affected in exotic Russian knapweed, and was sometimes decreased in downy brome. Because natives showed only small positive responses to litter and fertilization and large negative responses to competition, Russian knapweed and downy brome are likely to perform better than these two native species following tamarisk dieback.

  5. Proximate composition and amino acid profile of rice husk ...

    African Journals Online (AJOL)

    Native rice husk (NRH) was fermented with Pleurotus ostreatus for 7, 14 and 21 days to improve the nutritional values. The proximate composition and amino acid profiles were determined. The results showed that crude fibre (CF), nitrogen free extract (NFE), acid detergent fibre (ADF), and neutral detergent fibre (NDF) were ...

  6. Creating a Pronunciation Profile of First-Year Spanish Students

    Science.gov (United States)

    Añorga, Angel; Benander, Ruth

    2015-01-01

    Previous research has shown that improving pronunciation in the foreign language classroom is challenging, and there is often little time left over in a dense curriculum for pronunciation practice. In describing a pronunciation profile for all phonemes in Spanish, this study suggests that the principal challenge for native speakers of English who…

  7. Parasites, pathogens and commensals in the "low-impact" non-native amphipod host Gammarus roeselii.

    Science.gov (United States)

    Bojko, Jamie; Bącela-Spychalska, Karolina; Stebbing, Paul D; Dunn, Alison M; Grabowski, Michał; Rachalewski, Michał; Stentiford, Grant D

    2017-04-20

    Whilst vastly understudied, pathogens of non-native species (NNS) are increasingly recognised as important threats to native wildlife. This study builds upon recent recommendations for improved screening for pathogens in NNS by focusing on populations of Gammarus roeselii in Chojna, north-western Poland. At this location, and in other parts of continental Europe, G. roeselii is considered a well-established and relatively 'low-impact' invader, with little understanding about its underlying pathogen profile and even less on potential spill-over of these pathogens to native species. Using a combination of histological, ultrastructural and phylogenetic approaches, we define a pathogen profile for non-native populations of G. roeselii in Poland. This profile comprised acanthocephalans (Polymorphus minutus Goese, 1782 and Pomphorhynchus sp.), digenean trematodes, commensal rotifers, commensal and parasitic ciliated protists, gregarines, microsporidia, a putative rickettsia-like organism, filamentous bacteria and two viral pathogens, the majority of which are previously unknown to science. To demonstrate potential for such pathogenic risks to be characterised from a taxonomic perspective, one of the pathogens, a novel microsporidian, is described based upon its pathology, developmental cycle and SSU rRNA gene phylogeny. The novel microsporidian Cucumispora roeselii n. sp. displayed closest morphological and phylogenetic similarity to two previously described taxa, Cucumispora dikerogammari (Ovcharenko & Kurandina, 1987), and Cucumispora ornata Bojko, Dunn, Stebbing, Ross, Kerr & Stentiford, 2015. In addition to our discovery extending the host range for the genus Cucumispora Ovcharenko, Bacela, Wilkinson, Ironside, Rigaud & Wattier, 2010 outside of the amphipod host genus Dikerogammarus Stebbing, we reveal significant potential for the co-transfer of (previously unknown) pathogens alongside this host when invading novel locations. This study highlights the importance of

  8. Will HTML5 Kill the Native App?

    Science.gov (United States)

    Fredette, Michelle

    2013-01-01

    For colleges and universities today, the question is no longer whether to develop a campus app or not. Instead, the debate has shifted to the best--and most cost-efficient--way to make campus applications accessible to the myriad devices and operating systems out there. Schools have a few options: They can develop multiple native app versions;…

  9. Quantitative Changes In Antibodies Against Onchocercal Native ...

    African Journals Online (AJOL)

    Serum antibodies to Onchocerca volvulus native sodium duodecylsulphate slat extracted antigens and epitopes recognized by three monoclonal antibodies designated Cam8, Cam22, and Cam28 were measured using indirect (sandwich) and competitive enzyme-linked immunosorbent assay (ELISA). Paired serum ...

  10. Stylized Figures: Inspired by Native American Art

    Science.gov (United States)

    Jensen, Susie B.

    2013-01-01

    Teaching elementary-level art in the Pacific Northwest makes it natural for the author to develop a lesson based on Native American art of the area. The designs of the Northwest Indians can sometimes be a bit too sophisticated for the students to grasp, however, and it can be frustrating when developing such a project. Over a Labor Day weekend,…

  11. Native American Rights Fund: 1982 Annual Report.

    Science.gov (United States)

    Native American Rights Fund, Boulder, CO.

    The 1982 annual report of the Native American Rights Fund (NARF), a non-profit organization specializing in the protection of Indian rights, explains the organization, its structure, its priorities, its activities, and its financial status. Opening statements by the chairman, Roger Jim, and the executive director, John Echohawk, note that despite…

  12. 76 FR 8375 - Alaska Native Claims Selection

    Science.gov (United States)

    2011-02-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management Alaska Native Claims Selection AGENCY: Bureau of Land Management, Interior.... 1 to 18, inclusive; Secs. 19 to 24, inclusive, those lands lying north of the highway right-of-way...

  13. Genetic characterization of native southern African chicken ...

    African Journals Online (AJOL)

    Unknown

    for the genetic conservation of poultry resources (Scherf, 1995). Similar projects have since been undertaken for all the major livestock species (Mason & Crawford, 1993). To date, native South African chicken lines have received very little scientific attention, and research projects have been directed primarily towards ...

  14. Examining Test Speededness by Native Language

    Science.gov (United States)

    Talento-Miller, Eileen; Guo, Fanmin; Han, Kyung T.

    2013-01-01

    When power tests include a time limit, it is important to assess the possibility of speededness for examinees. Past research on differential speededness has examined gender and ethnic subgroups in the United States on paper and pencil tests. When considering the needs of a global audience, research regarding different native language speakers is…

  15. Non-natives: 141 scientists object

    NARCIS (Netherlands)

    Simberloff, D.; Van der Putten, W.H.

    2011-01-01

    Supplementary information to: Non-natives: 141 scientists object Full list of co-signatories to a Correspondence published in Nature 475, 36 (2011); doi: 10.1038/475036a. Daniel Simberloff University of Tennessee, Knoxville, Tennessee, USA. dsimberloff@utk.edu Jake Alexander Institute of Integrative

  16. Digital Natives: Where Is the Evidence?

    Science.gov (United States)

    Helsper, Ellen Johanna; Eynon, Rebecca

    2010-01-01

    Generational differences are seen as the cause of wide shifts in our ability to engage with technologies and the concept of the digital native has gained popularity in certain areas of policy and practice. This paper provides evidence, through the analysis of a nationally representative survey in the UK, that generation is only one of the…

  17. Jurisprudence, Peyote and the Native American Church.

    Science.gov (United States)

    Lawson, Paul E.; Scholes, Jennifer

    1986-01-01

    Examines federal and state governments' attempts to suppress peyote use in Indian rituals as historically Christian-inspired. Focuses on questions of morality versus criminal law. Explains history and development of Native American Church of North America. Examines nine contemporary peyote trials. Concludes larger questions of tribal sovereignty…

  18. Native plant development and deployment [Section VII

    Science.gov (United States)

    Jessica Wright; Kas Dumroese; Amy Symstad; Theresa Pitts-Singer; Jim Cane; Gary Krupnick; Peggy Olwell; Byron Love; Elizabeth Sellers; John Englert; Troy Wood

    2015-01-01

    Native plant materials are needed to create, enhance, or restore pollinator habitat. They provide critical foraging and breeding areas for wild and managed pollinator species, including transnational migratory species such as hummingbirds and monarch butterflies. Although many pollinators and plants are generalists, some have limited, obligate relationships (i.e., one...

  19. Native plant containers for restoration projects

    Science.gov (United States)

    Thomas D. Landis; David E. Steinfeld; R. Kasten Dumroese

    2010-01-01

    The choice of container is one of the most important considerations when growing or ordering native plants for a restoration project. Container characteristics affect not only growth and production efficiencies in the nursery, they can also have important consequences after outplanting. The challenging conditions on restoration sites require containers with...

  20. Left Dislocation in Near-Native French

    Science.gov (United States)

    Donaldson, Bryan

    2011-01-01

    The present study is concerned with the upper limits of SLA--specifically, mastery of the syntax-discourse interface in successful endstate learners of second-language (L2) French (near-native speakers). Left dislocation (LD) is a syntactic means of structuring spoken French discourse by marking topic. Its use requires speakers to coordinate…

  1. Native American Children's Books. Book Reviews.

    Science.gov (United States)

    Moulton, Kathryn Elizabeth; Cornelius, Carol

    1993-01-01

    Reviews 11 children's books, published 1990-93, suitable for elementary and middle school students, covering Native riddles; Hiawatha as founder of the Iroquois confederacy; Chief Seattle's famous speech; stories about Inuit life and Mexican village life during the 1500s; Sequoyah and the Cherokee alphabet; the Iroquois creation myth; Wampanoag…

  2. Conceptualizing Native Identity with a Multidimensional Model

    Science.gov (United States)

    Gonzalez, John; Bennett, Russell

    2011-01-01

    This study reports on a Native Identity Scale (NIS) adapted from an African American identity scale (Sellers et al., 1997). American Indian (AIs) and First Nations Canadian participants (N = 199) completed the NIS at powwows in the Upper Midwest. The majority of respondents were Ojibwe, but other tribal groups were represented. A principal…

  3. Influence of Family on Native American Students

    Science.gov (United States)

    Fox, Lisa J.

    2012-01-01

    "Native American"* postsecondary education students encounter several barriers to academic persistence including cultural assimilation issues, limited access to career information services, and an individual sense of duty and responsibility to remain tied to traditional spiritual values and beliefs systems, joined with family pressure to…

  4. Self-Development for Native American Adults.

    Science.gov (United States)

    Nevo, Dana; Wiese, Dorene

    This instructional package consists of activity guides, materials, and background information on selected areas pertinent to the self-development of a native American Indian participant group. Covered in its six units are the following topics: self-image and success (motivation and success, personal discovery, tools and assessment instruments,…

  5. New Granadan native populations: recent demographic research.

    Science.gov (United States)

    Villamarin, J A

    1982-01-01

    A survey of recent work on the demographic history of the colonial native populations in the area that is now Colombia is presented, with emphasis on the study of the Chibcha Indians. Information is included on published data, sources, issues, and future research questions.

  6. Nutritional studies in native, Thai Kadon pigs

    NARCIS (Netherlands)

    Vasupen, K

    2007-01-01

    In the North-East of Thailand native, so-called Kadon pigs are typically kept on small-holder farms. Kadon pig is believed to be on the edge of extinction and in 2003 it was designated as a protected species of production animals. The main objective of this thesis was to study various nutritional

  7. Genetic characterization of native southern African chicken ...

    African Journals Online (AJOL)

    This study presents the first results on the evaluation and selection of polymorphic microsatellite markers for the genetic characterization of native chicken populations in southern Africa. Blood samples for DNA extraction were obtained from five chicken lines from South Africa (Koekoek, New Hampshire, Naked-Neck, ...

  8. Does Language Testing Need the Native Speaker?

    Science.gov (United States)

    Davies, Alan

    2011-01-01

    Opinions differ on the importance of the native speaker's concept for language teaching and testing. This Commentary maintains that it is important and seeks to explain why. Three types of grammar are distinguished, the individual's, the community's and the human faculty of language. For first language teaching and testing it is the community's…

  9. Hybridisation between native Oreochromis species and introduced ...

    African Journals Online (AJOL)

    Hybridisation between native Oreochromis species and introduced Nile tilapia O. niloticus in the Kafue River, Zambia. ... Keywords: aquaculture, ecosystem tradeoffs, fisheries management, introgression, invasive species, microsatellites, Old World cichlids. African Journal of Aquatic Science 2014, 39(1): 23–34.

  10. Product inhibition in native-state proteolysis.

    Directory of Open Access Journals (Sweden)

    Joseph R Kasper

    Full Text Available The proteolysis kinetics of intact proteins by nonspecific proteases provides valuable information on transient partial unfolding of proteins under native conditions. Native-state proteolysis is an approach to utilize the proteolysis kinetics to assess the energetics of partial unfolding in a quantitative manner. In native-state proteolysis, folded proteins are incubated with nonspecific proteases, and the rate of proteolysis is determined from the disappearance of the intact protein. We report here that proteolysis of intact proteins by nonspecific proteases, thermolysin and subtilisin deviates from first-order kinetics. First-order kinetics has been assumed for the analysis of native-state proteolysis. By analyzing the kinetics of proteolysis with varying concentrations of substrate proteins and also with cleavage products, we found that the deviation from first-order kinetics results from product inhibition. A kinetic model including competitive product inhibition agrees well with the proteolysis time course and allows us to determine the uninhibited rate constant for proteolysis as well as the apparent inhibition constant. Our finding suggests that the likelihood of product inhibition must be considered for quantitative assessment of proteolysis kinetics.

  11. Coastal Culture Area. Native American Curriculum Series.

    Science.gov (United States)

    Ross, Cathy; Fernandes, Roger

    Background information, legends, games, illustrations, and art projects are provided in this booklet introducing elementary students to the history and culture of Indian tribes of the North Pacific Coast and Pacific Northwest. One in a series of Native American instructional materials, the booklet provides an overview of the coastal culture area,…

  12. Native Hawaiian Community College Students: What Happens?

    Science.gov (United States)

    Hagedorn, Linda Serra; Lester, Jaime; Moon, Hye Sun; Tibbetts, Katherine

    2006-01-01

    Using a weighted database of approximately 3,000 students, this study involves the tracing of the postsecondary history of 2,516 students who identified as Native Hawaiian, graduated from high school between 1993 and 1995, and attended college. Virtually none of the students are 100% Hawaiian. Due to a long history of intermarriage, the Hawaiian…

  13. Structure of the mantle lithosphere beneath the Siberian kimberlite pipes reconstructed by monomineral thermobarometry

    Science.gov (United States)

    Ashchepkov, I. V.

    2009-04-01

    columns (10-13) is reconstructed by the stepped TPX trends formed at first by the combinations of subduction and superplume events coinciding with the Re/Os ages (Spetsius, 2007), overprinted by the reactions with the plume and other percolating melts The Fe# increase near the 60 kbar refer to the last superplume events the previous leave similar rhythmic Fe- dunite horizons at 11-12 levels. The comparison of the compositions of minerals and reconstruction of mantle roots for several phases for Yubileinay, Udachnaya and Nyurbinskaya pipes allow to reveal the evolution of the magmatic sources and their interaction with the mantle lithosphere. Reconstruction of the mantle columns beneath 60 pipes allow to make the transsects of the kimberlite fields and the 3D model of the mantle beneath the dense kimberlite clusters with many close located diatrems Mesozoic mantle columns beneath the Anabar, Olenek, Aldan show the HT -Fe# alteration in 60-40 kbar due to interaction with the PT superplume, but relic and LT and low Fe# associations occurs to 60 kbar also. RBRF 05-05-74718, 06-05-65021, 06-05-64416.

  14. Rapid Mantle Ascent Rates Beneath Brazil: Diamond Bullets from a Smoking Plume?

    Science.gov (United States)

    Walter, M. J.; Frost, D. J.

    2010-12-01

    inclusions in diamonds from Juina also provide evidence for mantle ascent of this magnitude [2, 3]. The questions are (1) over what timeframe do the diamonds ascend? (2) what causes mantle ascent beneath the craton? Bulanova et al [2] were able to obtain a U/Pb age for the J1 perovskite inclusion, giving an astonishingly young model age of 101 ±7 Ma, close to the eruption age of the host kimberlite (93 ±1.5 Ma). From the time and depth differences we calculate ascent rates of about 1 to 50 cm/yr. We suggest that such rapid rates of mantle ascent beneath a craton may be ascribed to buoyant upwelling of mantle material. Diamond speedometry may provide direct evidence for a Cretaceous plume beneath Brazil, which was ultimately responsible for alkaline and kimberlite magmatism, and probably the Trindade magmatic track [6]. 1. Harte et al., Geochem. Soc. Spec. Pub, 1999, 125-153. 2. Bulanova et al., CMP, 2010, DOI:10.1007/s00410-010-0490-6. 3. Harte and Cayzer, Phys. Chem. Min., 2007. 4. Shirey et al., Science, 2002. 297, 1683- 1686. 5. Walter et al., Nature, 2008. 454, 622-625. [6] Gibson et al., J Petrol, 1995, 36, 89-229.

  15. Seismological studies of the plumbing system beneath the Klyuchevskoy volcanic group in Kamchataka, Russia

    Science.gov (United States)

    Koulakov, I.; Shapiro, N.; Abkadyirov, I.; Gordeev, E.; Jakovlev, A.; Kugaenko, Y.; Droznin, D.; Droznina, S.; Senyukov, S.; Novgorodova, A.; Kulakov, R.; Deev, E.

    2016-12-01

    The Klyuchevskoy volcanic group (KVG) is one of largest and most active clusters of subduction-related volcanoes in the World. Within an area of 70 km size, there are 13 closely located stratovolcanoes, of which Klyuchevskoy, Bezymianny, and Tolbachik produced numerous strong eruptions during recent decades. The Klyuchevskoy and Tolbachik recent eruptions produced lavas of basaltic to basaltic-andesitic composition while Bezimyanny is an explosive andesitic volcano. We present a seismological study of the KVG plumbing system. The first part of our study is the tomographic imaging based on data of permanent and temporary seismic stations operated in vicinity of the KVG. Beneath the Klyuchevskoy volcano at depths between 28 and 35 km, we observe an anomaly with very high Vp/Vs ratio collocated with a large cluster of long-period volcanic earthquakes. We propose that this feature represents the top of the mantle magmatic reservoir feeding the KVG. A narrow seismicity cluster beneath the Klyuchevskoy volcano marks a straight vertical conduit bringing basic magma from the deep reservoir at 30 km to the surface. For the Bezymianny volcano, we observe a middle-crust reservoir at 15 km depth, where the light andesitic magma is fractioned and separated. For the Tolbachik volcano, linearly clustered seismicity and seismic anomalies indicate two distinct pathways of magma ascending. In summary, the new seismic model has revealed three different types of plumbing systems explaining the variability of eruption styles in Klyuchevskoy, Bezymyanny and Tolbachik volcanoes. In the second part we study the occurrence of long-period (LP) seismic events occurring within KVG during two years preceding the large eruption of Tolbachik started at the end of 2012. We find two distinct groups of LP sources: events that occurred just below the edifices of the active volcanoes, and events at depths of 30 km in the vicinity of a deep magmatic reservoir. The time histories of these deep and

  16. Crustal Seismic Structure beneath Portugal (Western Iberia) and the role of Variscan Inheritance

    Science.gov (United States)

    Veludo, Idalina; Afonso Dias, Nuno; Fonseca, Paulo; Matias, Luís; Carrilho, Fernando; Haberland, Christian; Villaseñor, Antonio

    2017-04-01

    Mainland Portugal comprises most of the Western portion of the Iberian Peninsula, in a geodynamic setting associated with the Africa-Eurasia plate boundary. The crustal structure in Portugal is the result of a complex assemblage history of continental collision and extension with most of the surface is covered by rocks dating to the Variscan orogeny, the coastal ranges dominated by Mesozoic structures and Mesocenozoic basins covering partially the mainland. The impact and extension of this complex tectonic in the structure of the Iberian Lithosphere is still a matter of discussion, especially in its western part beneath Portugal. The existing knowledge relating the observed surface geology and lithospheric structures is sparse and sometimes incoherent, the relation between shallow and deep structures and their lateral extension still widely undetermined. Some questions still pertinent are the role and influence of the several tectonic units and their contacts in the present tectonic regime and in the stress field observed today, and the relation between the anomalous seismicity and associated crustal deformation rates with the inherited structure from past orogenies. In this study we present the results of a local earthquake tomographic study, performed to image this complex crustal structure down to 20 km depth. The relocation of the onshore seismicity recorded in the period 2000-2014 with the new 3D model allows cleansing some of the alignments and their correlation with some of the main active structures in Portugal enabling for the first time to correlate a large number of tectonic features to the small magnitude seismicity pattern. The seismicity distribution also displays a complex pattern, mainly reflecting the interaction between inherited Variscan structures with more recent fault systems created during the rifting stages of the Atlantic and diapir magmatic intrusions. The complex history of the assemblage of the crust beneath Western Iberia is well

  17. Thermal-Mechanical Regime beneath Tarim Basin, Northwestern China and its Implications for Cenozoic Tectonics

    Science.gov (United States)

    Liu, S.; Wang, L.

    2005-12-01

    As one of the super-large scale sedimentary basins in China, the Tarim basin is also the strategic basement for Chinese `Natural gas transportation from west to east' project. To know its thermal regime is vital for understanding the deformation and oil gas resource in Tarim basin. Integrated the abundant data of geotemperature and rock thermophysical parameters collected and measured in the basin with corresponding geothermal modeling, here we present the characteristics of geotemperature field, thermal evolution and lithospheric thermo-rheological structure of the Tarim basin, along with the implications for formation and deformation of basin and hydrocarbon reservoir. Our results show that the average present-day heat flow of the basin is about 45 mW/m2 and 18-20°/km for geotemperature gradient, respectively. The basin is characterized by lower temperature in a whole. Lateral heterogeneities exist for the distribution of geotemperature field in the basin. The structural units of basin differ much in the geothermal features; generally, the depression areas are of relatively low geotemperature while high for those uplifts and highs in the basin. Thermal evolution modeling of the basin indicated that it has experienced four different phases since basin formation as follows: high heat flow phase from Sinian to Ordovician, thermal attenuation phase during Silurian to late Paleozoic, then stable thermal evolution phase in Mesozoic, and flexural deformation of lithosphere in Cenozoic. The thickness of the thermal lithosphere of basin is 168-192 km, and 25-28km for the crustal brittle-ductile transition depth; the total lithospheric strength is 1.6-7.8*10**13 N/m. The lithosphere beneath basin is characterized by the rigid block with low temperature but large strength, and deform in a whole. Responded to the far field effect of the Cenozoic India-Eurasia collision, the lithosphere beneath Tarim basin is characterized by flexure deformation, resulting in the intensive

  18. Orogen-parallel Variation in Flexure of the Arabian Plate Beneath the Zagros Mountains

    Science.gov (United States)

    Pirouz, M.; Avouac, J. P.; Simpson, G.; Hassanzadeh, J.; Herman, F.; Sternai, P.

    2014-12-01

    The Zagros Mountains are the part of the Alpine-Himalayan chain that forms the northern margin of the Arabian plate and comprises a Neogene-Recent sedimentary basin that is forming in response to ongoing Arabia-Eurasia collision. Flexure of the Arabian lithosphere beneath the Zagros forms one of largest and most active basins in the world at which a backstripped deflection of a competent layer just below the foreland deposits represents its total amount of tectonic subsidence. As such, the Asmari Fm. can be used to analyze flexural bending and subsequently the amount of loading and elastic thickness of the Arabian lithosphere since the continent-continent collision started. In this study, flexure of the Arabian lithosphere is investigated using more than 100 boreholes and 60 interpreted seismic lines which show that the flexure is shallower (~ 1 km) and wider in the east and deeper (~6 km) and narrower towards the west (Figure 1). The shallow and wide eastern foredeep has little accommodation space due to small tectonic loads and the thick lithosphere in this region. In addition, viscous strength in the eastern sector leads to a wide deformation belt with low topography and low surface slopes. These factors, combined with arid climatic conditions, produce low sediment supply to the foreland basin so that it remains under-filled even though the foreland basin is shallow. In contrast, the western part of the Zagros region shows much larger accommodation space due to the combination of large loads and a relatively thin elastic plate. In the western sector, frictional basal strength and steeper topography along with more humid climatic conditions leading to a large supply of sediment to the foreland which is completely filled even though the foreland basin is deep. Our results also show that the Zagros foreland basin migrated towards south through the Neogene; however, the way of propagation is not fully understood yet. The eastern depocenter of the Zagros foreland

  19. Investigation of mantle kinematics beneath the Hellenic-subduction zone with teleseismic direct shear waves

    Science.gov (United States)

    Confal, Judith M.; Eken, Tuna; Tilmann, Frederik; Yolsal-Çevikbilen, Seda; Çubuk-Sabuncu, Yeşim; Saygin, Erdinc; Taymaz, Tuncay

    2016-12-01

    The subduction and roll-back of the African plate beneath the Eurasian plate along the arcuate Hellenic trench is the dominant geodynamic process in the Aegean and western Anatolia. Mantle flow and lithospheric kinematics in this region can potentially be understood better by mapping seismic anisotropy. This study uses direct shear-wave splitting measurements based on the Reference Station Technique in the southern Aegean Sea to reveal seismic anisotropy in the mantle. The technique overcomes possible contamination from source-side anisotropy on direct S-wave signals recorded at a station pair by maximizing the correlation between the seismic traces at reference and target stations after correcting the reference stations for known receiver-side anisotropy and the target stations for arbitrary splitting parameters probed via a grid search. We obtained splitting parameters at 35 stations with good-quality S-wave signals extracted from 81 teleseismic events. Employing direct S-waves enabled more stable and reliable splitting measurements than previously possible, based on sparse SKS data at temporary stations, with one to five events for local SKS studies, compared with an average of 12 events for each station in this study. The fast polarization directions mostly show NNE-SSW orientation with splitting time delays between 1.15 s and 1.62 s. Two stations in the west close to the Hellenic Trench and one in the east show N-S oriented fast polarizations. In the back-arc region three stations exhibit NE-SW orientation. The overall fast polarization variations tend to be similar to those obtained from previous SKS splitting studies in the region but indicate a more consistent pattern, most likely due to the usage of a larger number of individual observations in direct S-wave derived splitting measurements. Splitting analysis on direct shear waves typically resulted in larger split time delays compared to previous studies, possibly because S-waves travel along a longer path

  20. Analysis of Consumers' Preferences and Price Sensitivity to Native Chickens.

    Science.gov (United States)

    Lee, Min-A; Jung, Yoojin; Jo, Cheorun; Park, Ji-Young; Nam, Ki-Chang

    2017-01-01

    This study analyzed consumers' preferences and price sensitivity to native chickens. A survey was conducted from Jan 6 to 17, 2014, and data were collected from consumers (n=500) living in Korea. Statistical analyses evaluated the consumption patterns of native chickens, preference marketing for native chicken breeds which will be newly developed, and price sensitivity measurement (PSM). Of the subjects who preferred broilers, 24.3% do not purchase native chickens because of the dryness and tough texture, while those who preferred native chickens liked their chewy texture (38.2%). Of the total subjects, 38.2% preferred fried native chickens (38.2%) for processed food, 38.4% preferred direct sales for native chicken distribution, 51.0% preferred native chickens to be slaughtered in specialty stores, and 32.4% wanted easy access to native chickens. Additionally, the price stress range (PSR) was 50 won and the point of marginal cheapness (PMC) and point of marginal expensiveness (PME) were 6,980 won and 12,300 won, respectively. Evaluation of the segmentation market revealed that consumers who prefer broiler to native chicken breeds were more sensitive to the chicken price. To accelerate the consumption of newly developed native chicken meat, it is necessary to develop a texture that each consumer needs, to increase the accessibility of native chickens, and to have diverse menus and recipes as well as reasonable pricing for native chickens.

  1. Analysis of Consumers’ Preferences and Price Sensitivity to Native Chickens

    Science.gov (United States)

    Lee, Min-A; Jung, Yoojin; Jo, Cheorun

    2017-01-01

    This study analyzed consumers’ preferences and price sensitivity to native chickens. A survey was conducted from Jan 6 to 17, 2014, and data were collected from consumers (n=500) living in Korea. Statistical analyses evaluated the consumption patterns of native chickens, preference marketing for native chicken breeds which will be newly developed, and price sensitivity measurement (PSM). Of the subjects who preferred broilers, 24.3% do not purchase native chickens because of the dryness and tough texture, while those who preferred native chickens liked their chewy texture (38.2%). Of the total subjects, 38.2% preferred fried native chickens (38.2%) for processed food, 38.4% preferred direct sales for native chicken distribution, 51.0% preferred native chickens to be slaughtered in specialty stores, and 32.4% wanted easy access to native chickens. Additionally, the price stress range (PSR) was 50 won and the point of marginal cheapness (PMC) and point of marginal expensiveness (PME) were 6,980 won and 12,300 won, respectively. Evaluation of the segmentation market revealed that consumers who prefer broiler to native chicken breeds were more sensitive to the chicken price. To accelerate the consumption of newly developed native chicken meat, it is necessary to develop a texture that each consumer needs, to increase the accessibility of native chickens, and to have diverse menus and recipes as well as reasonable pricing for native chickens. PMID:28747834

  2. Lexical complexity: Metaphors and collocations in native, non-native and bilingual speech

    OpenAIRE

    Gouteraux, Pascale

    2017-01-01

    International audience; This paper reports on a study of metaphorical speech produced by forty native, non-native and bilingual students from University Paris-Diderot expressing themselves in English and in French. A corpus of spontaneous reactions to works of art was collected within the framework of Emphiline, an interdisciplinary project exploring the expression of surprise and associated emotions. Recent studies have bridged the gap between the Cognitive Linguistics definition of conceptu...

  3. Native and Non-Native Supergeneralist Bee Species Have Different Effects on Plant-Bee Networks

    OpenAIRE

    Tereza C Giannini; Garibaldi, Lucas A; Acosta, Andre L.; Silva, Juliana S.; Maia, Kate P.; Saraiva,Antonio M.; Guimarães, Paulo R; Kleinert,Astrid M. P.

    2015-01-01

    Supergeneralists, defined as species that interact with multiple groups of species in ecological networks, can act as important connectors of otherwise disconnected species subsets. In Brazil, there are two supergeneralist bees: the honeybee Apis mellifera, a non-native species, and Trigona spinipes, a native stingless bee. We compared the role of both species and the effect of geographic and local factors on networks by addressing three questions: 1) Do both species have similar abundance an...

  4. Upper mantle structure beneath the Hawaiian swell: Constraints from the ocean seismic network pilot experiment

    Science.gov (United States)

    Collins, J. A.; Vernon, F. L.; Orcutt, J. A.; Stephen, R. A.

    2002-06-01

    Data from two broadband, ocean-bottom seismographic stations deployed ~225 km southwest of Oahu, Hawaii during the Ocean Seismic Network Pilot Experiment provide constraints on upper mantle structure beneath the Hawaiian swell. Receiver functions show that the mantle transition zone is thinned by >50 km relative to reference model PA5, which, in the absence of compositional changes, implies excess temperatures of >350 K in the transition zone. The combination of the measurements reported here and the thickness variations reported by Li et al. [2000] imply that the transition zone is thinned by 30 +/- 15 km over an along-swell dimension of at least 700 km. At ~80 km depth, P-to-S converted phases are identified from the Gutenberg discontinuity marking the lid of the oceanic low-velocity zone and the base of the lithosphere. Shear-wave splitting measurements imply that fast-polarization azimuths are intermediate between the absolute plate-motion vector and the fossil spreading direction; multi-event stacked values of ø and δt are -80° and 1.5 s, respectively.

  5. The lithosphere structure beneath the central Mediterranean from S receiver functions

    Science.gov (United States)

    Bianchi, Irene; Miller, Meghan; Piana Agostinetti, Nicola; O'Driscoll, Leland

    2017-04-01

    The last piece of Mesozoic oceanic lithosphere from the Neo-Tethys Ocean is being consumed beneath Eurasia in the Central Mediterranean area, squeezed by the continuing convergence of Africa with the Eurasian plate. Convergence between Africa and Eurasia has been ongoing since the Cenozoic, forming a series of arcuate shaped subduction zones, and producing the current complex plate boundary that strikes across the Mediterranean area. Moreover, geophysical imaging depicts a variable lithospheric structure related to remnants of both oceanic and continental lithosphere within this convergent margin, which contributes to its complexity. In fact, the subduction/collision of blocks with different rheologies and thicknesses (e.g. continental or oceanic) has resulted in complex setting that includes accretionary wedges, orogenesis, and formation of an intricate back-arc/fore-arc/trench system. In order to shed light on these tectonic structures, we provide observations and interpretations of the lithospheric structure of the central Mediterranean via S receiver functions analysis. Teleseismic observations recorded at permanent and temporary seismic stations have been employed to produce images of the lithospheric discontinuities with tens of kilometers lateral resolution. We illustrate the feasibility of the lithosphere-asthenosphere boundary detection on a regional scale, and detect the occurrence of deeper seismic discontinuities due both to positive and negative seismic velocity jumps.

  6. Nitrogen and carbon dynamics beneath on-site wastewater treatment systems in Pitt County, North Carolina.

    Science.gov (United States)

    Del Rosario, Katie L; Humphrey, Charles P; Mitra, Siddhartha; O'Driscoll, Michael A

    2014-01-01

    On-site wastewater treatment systems (OWS) are a potentially significant non-point source of nutrients to groundwater and surface waters, and are extensively used in coastal North Carolina. The goal of this study was to determine the treatment efficiency of four OWS in reducing total dissolved nitrogen (TDN) and dissolved organic carbon (DOC) concentrations before discharge to groundwater and/or adjacent surface water. Piezometers were installed for groundwater sample collection and nutrient analysis at four separate residences that use OWS. Septic tank effluent, groundwater, and surface water samples (from an adjacent stream) were collected four times during 2012 for TDN and DOC analysis and pH, temperature, electrical conductivity, and dissolved oxygen measurements. Treatment efficiencies from the tank to the groundwater beneath the drainfields ranged from 33 to 95% for TDN and 45 to 82% for DOC, although dilution accounted for most of the concentration reductions. There was a significant positive correlation between nitrate concentration and separation distance from trench bottom to water table and a significant negative correlation between DOC concentration and separation distance. The TDN and DOC transport (>15 m) from two OWS with groundwater saturated drainfield trenches was significant.

  7. Current ecological understanding of fungal-like pathogens of fish: what lies beneath?

    Directory of Open Access Journals (Sweden)

    Rodolphe Elie Gozlan

    2014-02-01

    Full Text Available Despite increasingly sophisticated microbiological techniques, and long after the first discovery of microbes, basic knowledge is still lacking to fully appreciate the ecological importance of microbial parasites in fish. This is likely due to the nature of their habitats as many species of fish suffer from living beneath turbid water away from easy recording. However, fishes represent key ecosystem services for millions of people around the world and the absence of a functional ecological understanding of viruses, prokaryotes, and small eukaryotes in the maintenance of fish populations and of their diversity represents an inherent barrier to aquatic conservation and food security. Among recent emerging infectious diseases responsible for severe population declines in plant and animal taxa, fungal and fungal-like microbes have emerged as significant contributors. Here, we review the current knowledge gaps of fungal and fungal-like parasites and pathogens in fish and put them into an ecological perspective with direct implications for the monitoring of fungal fish pathogens in the wild, their phylogeography as well as their associated ecological impact on fish populations. With increasing fish movement around the world for farming, releases into the wild for sport fishing and human-driven habitat changes, it is expected, along with improved environmental monitoring of fungal and fungal-like infections, that the full extent of the impact of these pathogens on wild fish populations will soon emerge as a major threat to freshwater biodiversity.

  8. First evidence for high anelastic attenuation beneath the Red Sea from Love wave analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hadiouche, Ouiza (Seismologisches Zentralobservatorium, Erlangen (West Germany))

    1990-10-01

    Attenuation coefficients of Love waves are determined for two seismic paths along the Red Sea. The attenuation coefficients are obtained using the multiple filter method for periods from 25 to 130 s along one path and from 40 to 130 s along the second one. The two sets of observations are in good agreement with anomalously high attenuation coefficients similar to those reported across a young part of the Pacific Ocean. Indeed, the values lie on average between 3.3 {plus minus} 0.6 and 1.1 {plus minus} 0.3 (10{sup {minus}4}km{sup {minus}1}) higher values being observed at shorter periods. In a second part of the paper, these apparent attenuation observations are interpreted in terms of a distribution of intrinsic absorption in the upper mantle. A frequency independent Q{sub {beta}} model is obtained using a trial-and-error method. The best fit to the data required a large and very low Q{sub {beta}} (30-50) zone below a depth of 50 km, underlying a thin and high Q{sub {beta}} (200-300) lid. These results are consistent with high heat flows and low velocities which characterize this tectonically active area, and corroborate the inference of anomalously high temperatures and low viscosity in the upper mantle beneath the Red Sea from recent seismological results.

  9. The efficiency of different light sources to polymerize resin cement beneath porcelain laminate veneers.

    Science.gov (United States)

    Usumez, A; Ozturk, A N; Usumez, S; Ozturk, B

    2004-02-01

    Plasma arc light units for curing resin composites have been introduced with the claim of relatively short curing times. The purpose of this study was to evaluate the efficiency of two different light sources to polymerize dual curing resin cement beneath porcelain laminate veneers. Twenty extracted healthy human maxillary centrals were used. Teeth were sectioned 2 mm below the cemento-enamel junction and crown parts were embedded into self-cure acrylic resin, labial surface facing up. Cavity preparation was carried out on labial surfaces. These teeth were divided into two groups of 10 each. The resin cement/veneer combination was exposed to two different photo polymerization units. A conventional halogen light (Hilux 350, Express Dental Products) and a plasma arc light (Power PAC, ADT) were used to polymerize resin cement. Ten specimens were polymerized conventionally (40 s) and the other specimens by plasma arc curing (PAC) (6 s). Two samples from each tooth measuring 1.2 x 1.2 x 5 mm were prepared. These sections were subjected to microshear testing and failure values were recorded. Statistically significant differences were found between the bond strength of veneers exposed to conventional light and PAC unit (P < 0.001). Samples polymerized with halogen light showed better bond strength. The results of this study suggest that the curing efficiency of PAC through ceramic was lower compared with conventional polymerization for the exposure durations tested in this study.

  10. Determination of Moho depth and dip beneath MEDNET station AQU by analysis of broadband receiver functions

    Directory of Open Access Journals (Sweden)

    A. Morelli

    1994-06-01

    Full Text Available We applied the receiver function technique to retrieve Moho depth and dip beneath the MEDNET very-broadband seismographic station at l'Aquila, in the Central Apennines. Broadband data available for teleseismic events recorded in two years of operation were sufficient to delineate a rather simple structure consisting of a 32-34 km thick crust, in agreement with previous studies based on refraction seismics. In addition, the data show relatively large variation in the amplitude of the converted P-to-S phase generated at the crust-mantle interface as a function of azimuth. These variations are consistent with synthetic receiver functions generated for an incident P wave interacting with an interface dipping ~ 8° to the north. Observations of amplitude ratios of converted phases, polarity of first-motion in the SH directíon, and relative travel time delay are all consistent with a model assuming a Moho discontinuity about 33 km deep gently dipping towards north. The receiver function technique has shown to be an efficient tool for investigating deep crustal structure, giving localized but reliable information.

  11. Pathway from subducting slab to surface for melt and fluids beneath Mount Rainier.

    Science.gov (United States)

    McGary, R Shane; Evans, Rob L; Wannamaker, Philip E; Elsenbeck, Jimmy; Rondenay, Stéphane

    2014-07-17

    Convergent margin volcanism originates with partial melting, primarily of the upper mantle, into which the subducting slab descends. Melting of this material can occur in one of two ways. The flow induced in the mantle by the slab can result in upwelling and melting through adiabatic decompression. Alternatively, fluids released from the descending slab through dehydration reactions can migrate into the hot mantle wedge, inducing melting by lowering the solidus temperature. The two mechanisms are not mutually exclusive. In either case, the buoyant melts make their way towards the surface to reside in the crust or to be extruded as lava. Here we use magnetotelluric data collected across the central state of Washington, USA, to image the complete pathway for the fluid-melt phase. By incorporating constraints from a collocated seismic study into the magnetotelluric inversion process, we obtain superior constraints on the fluids and melt in a subduction setting. Specifically, we are able to identify and connect fluid release at or near the top of the slab, migration of fluids into the overlying mantle wedge, melting in the wedge, and transport of the melt/fluid phase to a reservoir in the crust beneath Mt Rainier.

  12. Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf

    Science.gov (United States)

    Garabato, Alberto C. Naveira; Forryan, Alexander; Dutrieux, Pierre; Brannigan, Liam; Biddle, Louise C.; Heywood, Karen J.; Jenkins, Adrian; Firing, Yvonne L.; Kimura, Satoshi

    2017-01-01

    The instability and accelerated melting of the Antarctic Ice Sheet are among the foremost elements of contemporary global climate change. The increased freshwater output from Antarctica is important in determining sea level rise, the fate of Antarctic sea ice and its effect on the Earth’s albedo, ongoing changes in global deep-ocean ventilation, and the evolution of Southern Ocean ecosystems and carbon cycling. A key uncertainty in assessing and predicting the impacts of Antarctic Ice Sheet melting concerns the vertical distribution of the exported meltwater. This is usually represented by climate-scale models as a near-surface freshwater input to the ocean, yet measurements around Antarctica reveal the meltwater to be concentrated at deeper levels. Here we use observations of the turbulent properties of the meltwater outflows from beneath a rapidly melting Antarctic ice shelf to identify the mechanism responsible for the depth of the meltwater. We show that the initial ascent of the meltwater outflow from the ice shelf cavity triggers a centrifugal overturning instability that grows by extracting kinetic energy from the lateral shear of the background oceanic flow. The instability promotes vigorous lateral export, rapid dilution by turbulent mixing, and finally settling of meltwater at depth. We use an idealized ocean circulation model to show that this mechanism is relevant to a broad spectrum of Antarctic ice shelves. Our findings demonstrate that the mechanism producing meltwater at depth is a dynamically robust feature of Antarctic melting that should be incorporated into climate-scale models.

  13. Density and stability of soil organic carbon beneath impervious surfaces in urban areas.

    Science.gov (United States)

    Wei, Zongqiang; Wu, Shaohua; Yan, Xiao; Zhou, Shenglu

    2014-01-01

    Installation of impervious surfaces in urban areas has attracted increasing attention due to its potential hazard to urban ecosystems. Urban soils are suggested to have robust carbon (C) sequestration capacity; however, the C stocks and dynamics in the soils covered by impervious surfaces that dominate urban areas are still not well characterized. We compared soil organic C (SOC) densities and their stabilities under impervious surface, determined by a 28-d incubation experiment, with those in open areas in Yixing City, China. The SOC density (0-20 cm) under impervious surfaces was, on average, 68% lower than that in open areas. Furthermore, there was a significantly (Psoils, whereas the correlation was not apparent for the impervious-covered soils, suggesting that the artificial soil sealing in urban areas decoupled the cycle of C and N. Cumulative CO2-C evolved during the 28-d incubation was lower from the impervious-covered soils than from the open soils, and agreed well with a first-order decay model (Ct = C1+C0(1-e-kt)). The model results indicated that the SOC underlying capped surfaces had weaker decomposability and lower turnover rate. Our results confirm the unique character of urban SOC, especially that beneath impervious surface, and suggest that scientific and management views on regional SOC assessment may need to consider the role of urban carbon stocks.

  14. Density and stability of soil organic carbon beneath impervious surfaces in urban areas.

    Directory of Open Access Journals (Sweden)

    Zongqiang Wei

    Full Text Available Installation of impervious surfaces in urban areas has attracted increasing attention due to its potential hazard to urban ecosystems. Urban soils are suggested to have robust carbon (C sequestration capacity; however, the C stocks and dynamics in the soils covered by impervious surfaces that dominate urban areas are still not well characterized. We compared soil organic C (SOC densities and their stabilities under impervious surface, determined by a 28-d incubation experiment, with those in open areas in Yixing City, China. The SOC density (0-20 cm under impervious surfaces was, on average, 68% lower than that in open areas. Furthermore, there was a significantly (P<0.05 positive correlation between the densities of SOC and total nitrogen (N in the open soils, whereas the correlation was not apparent for the impervious-covered soils, suggesting that the artificial soil sealing in urban areas decoupled the cycle of C and N. Cumulative CO2-C evolved during the 28-d incubation was lower from the impervious-covered soils than from the open soils, and agreed well with a first-order decay model (Ct = C1+C0(1-e-kt. The model results indicated that the SOC underlying capped surfaces had weaker decomposability and lower turnover rate. Our results confirm the unique character of urban SOC, especially that beneath impervious surface, and suggest that scientific and management views on regional SOC assessment may need to consider the role of urban carbon stocks.

  15. Slow slip rate and excitation efficiency of deep low-frequency tremors beneath southwest Japan

    Science.gov (United States)

    Daiku, Kumiko; Hiramatsu, Yoshihiro; Matsuzawa, Takanori; Mizukami, Tomoyuki

    2018-01-01

    We estimated the long-term average slip rate on the plate interface across the Nankai subduction zone during 2002-2013 using deep low-frequency tremors as a proxy for short-term slow slip events based on empirical relations between the seismic moment of short-term slow slip events and tremor activities. The slip rate in each region is likely to compensate for differences between the convergence rate and the slip deficit rate of the subducting Philippine Sea plate estimated geodetically, although the uncertainty is large. This implies that the strain because of the subduction of the plate is partially stored as the slip deficit and partially released by slow slip events during the interseismic period. The excitation efficiency of the tremors for the slow slip events differs among regions: it is high in the northern Kii region. Some events in the western Shikoku region show a somewhat large value. Antigorite serpentinite of two types exists in the mantle wedge beneath southwest Japan. Slips with more effective excitation of tremors presumably occur in high-temperature conditions in the antigorite + olivine stability field. Other slip events with low excitation efficiency are distributed in the antigorite + brucite stability field. Considering the formation reactions of these minerals and their characteristic structures, events with high excitation efficiency can be correlated with a high pore fluid pressure condition. This result suggests that variation in pore fluid pressure on the plate interface affects the magnitude of tremors excited by slow slip events.

  16. Crustal seismic structure beneath the Deccan Traps area (Gujarat, India), from local travel-time tomography

    Science.gov (United States)

    Prajapati, Srichand; Kukarina, Ekaterina; Mishra, Santosh

    2016-03-01

    The Gujarat region in western India is known for its intra-plate seismic activity, including the Mw 7.7 Bhuj earthquake, a reverse-faulting event that reactivated normal faults of the Mesozoic Kachchh rift zone. The Late Cretaceous Deccan Traps, one of the largest igneous provinces on the Earth, cover the southern part of Gujarat. This study is aimed at bringing light to the crustal rift zone structure and likely origin of the Traps based on the velocity structure of the crust beneath Gujarat. Tomographic inversion of the Gujarat region was done using the non-linear, passive-source tomographic algorithm, LOTOS. We use high-quality arrival times of 22,280 P and 22,040 S waves from 3555 events recorded from August 2006 to May 2011 at 83 permanent and temporary stations installed in Gujarat state by the Institute of Seismological Research (ISR). We conclude that the resulting high-velocity anomalies, which reach down to the Moho, are most likely related to intrusives associated with the Deccan Traps. Low velocity anomalies are found in sediment-filled Mesozoic rift basins and are related to weakened zones of faults and fracturing. A low-velocity anomaly in the north of the region coincides with the seismogenic zone of the reactivated Kachchh rift system, which is apparently associated with the channel of the outpouring of Deccan basalt.

  17. Measurement of dynamic scattering beneath stationary layers using multiple-exposure laser speckle contrast analysis

    Science.gov (United States)

    Hirst, Evan; Thompson, Oliver; Andrews, Mike

    2013-02-01

    The retina/choroid structure is an example of a complex biological target featuring highly perfused tissues and vessel flows both near the surface and at some depth. Laser speckle imaging can be used to image blood flows but static scattering paths present a problem for extracting quantifiable data. The speckle contrast is artificially increased by any residual specular reflection and light paths where no moving scatterers are encountered. Here we present results from phantom experiments demonstrating that the static and dynamic contributions to laser speckle contrast can be separated when camera exposures of varying duration are used. The stationary contrast parameter follows the thickness and strength of the overlying scatterer while the dynamic proportion of the scatter resulting from vessel flows and Brownian motion is unchanged. The importance of separating the two scatter components is illustrated by in vivo measurements from a scarred human retina, where the effect of the un-perfused scar tissue can be decoupled from the dynamic speckle from the intact tissue beneath it.

  18. Upper crustal structure beneath East Java from ambient noise tomography: A preliminary result

    Energy Technology Data Exchange (ETDEWEB)

    Martha, Agustya Adi [Meteorological, Climatological and Geophysical Agency, Jakarta (Indonesia); Graduate Research on Earthquakes and Active Tectonics, Institut Teknologi Bandung, Bandung (Indonesia); Widiyantoro, Sri [Global Geophysics Group, Institut Teknologi Bandung, Bandung (Indonesia); Center for Disaster Mitigation, Institut Teknologi Bandung, Bandung (Indonesia); Cummins, Phil; Saygin, Erdinc [Research School of Earth Sciences, Australian National University, Canberra (Australia); Masturyono [Meteorological, Climatological and Geophysical Agency, Jakarta (Indonesia)

    2015-04-24

    East Java has a fairly complex geological structure. Physiographically East Java can be divided into three zones, i.e. the Southern Mountains zone in the southern part, the Kendeng zone in the middle part, and the Rembang zone in the northern part. Most of the seismic hazards in this region are due to processes in the upper crust. In this study, the Ambient Noise Tomography (ANT) method is used to image the upper crustal structure beneath East Java. We have used seismic waveform data recorded by 8Meteorological, Climatological and Geophysical Agency (BMKG) stationary seismographic stations and 16 portable seismographs installed for 2 to 8 weeks. The data were processed to obtain waveforms fromnoise cross-correlation between pairs of seismographic stations. Our preliminary results indicate that the Kendeng zone, an area of low gravity anomaly, is associated with a low velocity zone. On the other hand, the southern mountain range, which has a high gravity anomaly, is related to a high velocity anomaly as shown by our tomographic images.

  19. Upper crustal structure beneath East Java from ambient noise tomography: A preliminary result

    Science.gov (United States)

    Martha, Agustya Adi; Widiyantoro, Sri; Cummins, Phil; Saygin, Erdinc; Masturyono

    2015-04-01

    East Java has a fairly complex geological structure. Physiographically East Java can be divided into three zones, i.e. the Southern Mountains zone in the southern part, the Kendeng zone in the middle part, and the Rembang zone in the northern part. Most of the seismic hazards in this region are due to processes in the upper crust. In this study, the Ambient Noise Tomography (ANT) method is used to image the upper crustal structure beneath East Java. We have used seismic waveform data recorded by 8Meteorological, Climatological and Geophysical Agency (BMKG) stationary seismographic stations and 16 portable seismographs installed for 2 to 8 weeks. The data were processed to obtain waveforms fromnoise cross-correlation between pairs of seismographic stations. Our preliminary results indicate that the Kendeng zone, an area of low gravity anomaly, is associated with a low velocity zone. On the other hand, the southern mountain range, which has a high gravity anomaly, is related to a high velocity anomaly as shown by our tomographic images.

  20. Postcolonial Myth in Salman Rushdie’s The Ground Beneath Her Feet

    Directory of Open Access Journals (Sweden)

    Doncu Roxana Elena

    2014-01-01

    Full Text Available Postcolonial writers like Salman Rushdie often write back to the “empire” by appropriating myth and allegory. In The Ground beneath Her Feet, Rushdie rewrites the mythological story of Orpheus and Eurydice, using katabasis (the trope of the descent into Hell to comment both on the situation of the postcolonial writer from a personal perspective and to attempt a redefinition of postcolonial migrant identity-formation. Hell has a symbolic function, pointing both to the external context of globalization and migration (which results in the characters’ disorientation and to an interior space which can be interpreted either as a source of unrepressed energies and creativity (in a Romantic vein or as the space of the abject (in the manner of Julia Kristeva. The article sets out to investigate the complex ways in which the Orphic myth and katabasis are employed to shed light on the psychology of the creative artist and on the reconfiguration of identity that becomes the task of the postcolonial migrant subject. The journey into the underworld functions simultaneously as an allegory of artistic creation and identity reconstruction.