2,512 research outputs found

    Sedimentary record of coseismic subsidence in Hersek coastal lagoon (Izmit Bay, Turkey) and the late Holocene activity of the North Anatolian Fault

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    This research was funded by the European Union in the framework of the REL.I.E.F. (Reliable Information on Earthquake Faulting) project (EVG1‐CT‐2002‐00069). Copyright @ 2011 American Geophysical Union.The late Holocene activity of a restraining bend of the northern strand of the North Anatolian Fault in Izmit Bay was investigated by a sedimentological, geochemical, and paleoecological analysis of sediment cores from Hersek coastal lagoon, NW Turkey. The sediment cores show a succession of sedimentary sequences composed of three units separated by gradual transitions. The first unit is composed of a thin layer of shell debris-rich sediment in abrupt contact with the underlying organic-rich deposits. This unit is over-lain by a thick foraminifera-rich mud deposit, and the sequences are capped by an organic-rich mud unit. These sequences are interpreted as silting up, shallowing upward deposits, typical of a lagoon becoming isolated from the sea. We suggest that they represent the sedimentary signature of coseismic subsidence, which was caused by reverse slip at the Hersek bend, and tsunamis in Izmit Bay. Our radiocarbon-dated paleoseismological record indicates (1) the atypical collapse of the hanging wall during the 740 earthquake and (2) subsidence of the footwall during the 987, 1509, and 1719 earthquakes. This study contributes to the understanding of the dynamics of restraining bends, and it highlights the potential of coastal sediments for reconstructing past earthquakes and tsunamis in regions dominated by strike-slip deformations.This article is available through the Brunel Open Access Publishing Fun

    Spatial variability of 14C reservoir effects in Tibetan Plateau lakes

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    Abstract HKT-ISTP 2013 B

    The alwathba wetland reserve lake in Abu Dhabi, United Arab Emirates and its ostracod (seed shrimp) fauna

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    Al Wathba Wetland Reserve (AWWR) lake, in the United Arab Emirates (UAE), is an artificially created water body in a natural wetland region that experienced seasonal flooding before the establishment of the lake. The lake is mostly fed by treated waste water, and became a protected wetland reserve after the Greater Flamingo started to successfully breed in the area in 1998. Detailed monitoring of several hydrochemical parameters and water depth at nine stations and two inlets of treated water in the lake was conducted over a period of seven years starting in January 2010. As a result, the seed-shrimps (Ostracoda: Podocopida) Heterocypris salina, previously reported from a late Miocene location in the UAE, and Cyprinotus cingalensis were recorded for the modern fauna of the UAE for the first time. The presence of the ostracods only at the station with the lowest salinity in the AWWR Lake shows that their distribution is predominantly controlled by the salinity of the water which covered an extremely large range of more than two orders of magnitude (1.45-457%) at the different sampling sites and inlets during the monitoring period. Thus, the lake represents an interesting and important ecological research laboratory under semi-natural conditions

    Strange Particles from NEXUS 3

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    After discussing conceptual problems with the conventional string model, we present a new approach, based on a theoretically consistent multiple scattering formalism. First results for strange particle production in proton-proton scattering at 158 GeV and at 200 GeV (cms) are discussed.Comment: invited talk, given at the Strange Quark Matter Conference, Atlantic Beach, North Carolina, March 12-17, 200

    The Role of the Gut Microbiota in the Effects of Early-Life Stress and Dietary Fatty Acids on Later-Life Central and Metabolic Outcomes in Mice

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    Early-life stress (ELS) leads to increased vulnerability for mental and metabolic disorders. We have previously shown that a low dietary ω-6/ω-3 polyunsaturated fatty acid (PUFA) ratio protects against ELS-induced cognitive impairments. Due to the importance of the gut microbiota as a determinant of long-term health, we here study the impact of ELS and dietary PUFAs on the gut microbiota and how this relates to the previously described cognitive, metabolic, and fatty acid profiles. Male mice were exposed to ELS via the limited bedding and nesting paradigm (postnatal day (P)2 to P9 and to an early diet (P2 to P42) with an either high (15) or low (1) ω-6 linoleic acid to ω-3 alpha-linolenic acid ratio. 16S rRNA was sequenced and analyzed from fecal samples at P21, P42, and P180. Age impacted α- and ÎČ-diversity. ELS and diet together predicted variance in microbiota composition and affected the relative abundance of bacterial groups at several taxonomic levels in the short and long term. For example, age increased the abundance of the phyla Bacteroidetes, while it decreased Actinobacteria and Verrucomicrobia; ELS reduced the genera RC9 gut group and Rikenella, and the low ω-6/ω-3 diet reduced the abundance of the Firmicutes Erysipelotrichia. At P42, species abundance correlated with body fat mass and circulating leptin (e.g., Bacteroidetes and Proteobacteria taxa) and fatty acid profiles (e.g., Firmicutes taxa). This study gives novel insights into the impact of age, ELS, and dietary PUFAs on microbiota composition, providing potential targets for noninvasive (nutritional) modulation of ELS-induced deficits. IMPORTANCE Early-life stress (ELS) leads to increased vulnerability to develop mental and metabolic disorders; however, the biological mechanisms leading to such programming are not fully clear. Increased attention has been given to the importance of the gut microbiota as a determinant of long-term health and as a potential target for noninvasive nutritional strategies to protect against the negative impact of ELS. Here, we give novel insights into the complex interaction between ELS, early dietary ω-3 availability, and the gut microbiota across ages and provide new potential targets for (nutritional) modulation of the long-term effects of the early-life environment via the microbiota

    Precision Measurement of the π+→e+Îœe Branching Ratio in the PIENU Experiment

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    The PIENU experiment at TRIUMF aims to measure the branching ratio of the pion decay modes Rπ=[π+→e+Îœe(Îł)]/[π+→Ό+ΜΌ(Îł)] with precision of <0.1%. Precise measurement of Rπ provides a stringent test of electron-muon universality in weak interactions. The current status of the PIENU experiment and future prospects are presented

    Improved Search for Heavy Neutrinos in the Decay π→eÎœ\pi\rightarrow e\nu

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    A search for massive neutrinos has been made in the decay π→e+Îœ\pi\rightarrow e^+ \nu. No evidence was found for extra peaks in the positron energy spectrum indicative of pion decays involving massive neutrinos (π→e+Îœh\pi\rightarrow e^+ \nu_h). Upper limits (90 \% C.L.) on the neutrino mixing matrix element ∣Uei∣2|U_{ei}|^2 in the neutrino mass region 60--135 MeV/c2c^2 were set, which are %representing an order of magnitude improvement over previous results

    Status of the TRIUMF PIENU Experiment

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    The PIENU experiment at TRIUMF aims to measure the pion decay branching ratio R=Γ(π+→e+Îœe(Îł))/Γ(π+→Ό+ΜΌ(Îł))R={\Gamma}({\pi}^+{\rightarrow}e^+{\nu}_e({\gamma}))/{\Gamma}({\pi}^+{\rightarrow}{\mu}^+{\nu}_{\mu}({\gamma})) with precision <0.1<0.1% to provide a sensitive test of electron-muon universality in weak interactions. The current status of the PIENU experiment is presented.Comment: Talk presented CIPANP2015. 8 pages, LaTeX, 4 eps figure
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