Science.gov

Sample records for fast event recorder

  1. Videotape Recording of Classroom Events.

    ERIC Educational Resources Information Center

    Smith, Gary R.

    This ongoing project, which involves the videotaping of classroom events, is being conducted in order to: (1) build a collection of videotape records of excellent instruction in selected classrooms and in various curriculum areas while maintaining the natural flow of classroom activities; (2) enable teachers and student teachers to collect…

  2. 49 CFR 229.135 - Event recorders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... an event recorder with a certified crashworthy event recorder memory module that meets the... certified crashworthy event recorder memory module that meets the requirements of Appendix D of this part. The certified event recorder memory module shall be mounted for its maximum protection....

  3. 49 CFR 229.135 - Event recorders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... an event recorder with a certified crashworthy event recorder memory module that meets the... certified crashworthy event recorder memory module that meets the requirements of Appendix D of this part. The certified event recorder memory module shall be mounted for its maximum protection....

  4. 49 CFR 229.135 - Event recorders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... an event recorder with a certified crashworthy event recorder memory module that meets the... certified crashworthy event recorder memory module that meets the requirements of Appendix D of this part. The certified event recorder memory module shall be mounted for its maximum protection....

  5. 49 CFR 229.135 - Event recorders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... an event recorder with a certified crashworthy event recorder memory module that meets the... certified crashworthy event recorder memory module that meets the requirements of Appendix D of this part. The certified event recorder memory module shall be mounted for its maximum protection....

  6. 49 CFR 229.135 - Event recorders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... an event recorder with a certified crashworthy event recorder memory module that meets the... certified crashworthy event recorder memory module that meets the requirements of Appendix D of this part. The certified event recorder memory module shall be mounted for its maximum protection....

  7. Fast events in protein folding

    SciTech Connect

    Woodruff, W.; Callender, R.; Causgrove, T.; Dyer, R.; Williams, S.

    1996-04-01

    The primary objective of this work was to develop a molecular understanding of how proteins achieve their native three-dimensional (folded) structures. This requires the identification and characterization of intermediates in the protein folding process on all relevant timescales, from picoseconds to seconds. The short timescale events in protein folding have been entirely unknown. Prior to this work, state-of-the-art experimental approaches were limited to milliseconds or longer, when much of the folding process is already over. The gap between theory and experiment is enormous: current theoretical and computational methods cannot realistically model folding processes with lifetimes longer than one nanosecond. This unique approach to employ laser pump-probe techniques that combine novel methods of laser flash photolysis with time-resolved vibrational spectroscopic probes of protein transients. In this scheme, a short (picosecond to nanosecond) laser photolysis pulse was used to produce an instantaneous pH or temperature jump, thereby initiating a protein folding or unfolding reaction. Structure-specific, time-resolved vibrational probes were then used to identify and characterize protein folding intermediates.

  8. Subnoise detection of a fast random event.

    PubMed

    Ataie, V; Esman, D; Kuo, B P-P; Alic, N; Radic, S

    2015-12-11

    Observation of random, nonrepetitive phenomena is of critical importance in astronomy, spectroscopy, biology, and remote sensing. Heralded by weak signals, hidden in noise, they pose basic detection challenges. In contrast to repetitive waveforms, a single-instance signal cannot be separated from noise through averaging. Here, we show that a fast, randomly occurring event can be detected and extracted from a noisy background without conventional averaging. An isolated 80-picosecond pulse was received with confidence level exceeding 99%, even when accompanied by noise. Our detector relies on instantaneous spectral cloning and a single-step, coherent field processor. The ability to extract fast, subnoise events is expected to increase detection sensitivity in multiple disciplines. Additionally, the new spectral-cloning receiver can potentially intercept communication signals that are presently considered secure. PMID:26659052

  9. Event-recording devices with identification codes

    NASA Technical Reports Server (NTRS)

    Watters, David G. (Inventor); Huestis, David L. (Inventor); Bahr, Alfred J. (Inventor); Vidmar, Robert J. (Inventor)

    2003-01-01

    A recording device allows wireless interrogation to determine its identity and its state. The state indicates whether one or more physical or chemical events have taken place. In effect, the one or more physical or chemical events are recorded by the device. The identity of the device allows it to be distinguished from a number of similar devices. The recording device may be used in an array of devices that allows wireless probing by an interrogation unit. When probed, each device tells the interrogator who it is and what state it is in. The devices allow multiple use and the interrogator may use a logical reset to determine the state of each device. The interrogator can thus easily identify particular items in an array that have reached a particular condition. The device may record the status of each device in a database to maintain a history for each.

  10. 77 FR 59566 - Event Data Recorders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION National Highway Traffic Safety Administration 49 CFR Part 563 RIN 2127-AL14 Event Data Recorders Correction In rule document 2012-19580, appearing on pages 47552-47557 in the issue of Thursday, August...

  11. Biomarker Records Associated with Mass Extinction Events

    NASA Astrophysics Data System (ADS)

    Whiteside, Jessica H.; Grice, Kliti

    2016-06-01

    The history of life on Earth is punctuated by a series of mass extinction episodes that vary widely in their magnitude, duration, and cause. Biomarkers are a powerful tool for the reconstruction of historical environmental conditions and can therefore provide insights into the cause and responses to ancient extinction events. In examining the five largest mass extinctions in the geological record, investigators have used biomarkers to elucidate key processes such as eutrophy, euxinia, ocean acidification, changes in hydrological balance, and changes in atmospheric CO2. By using these molecular fossils to understand how Earth and its ecosystems have responded to unusual environmental activity during these extinctions, models can be made to predict how Earth will respond to future changes in its climate.

  12. Strong imprint of past orogenic events on the thermochronological record

    NASA Astrophysics Data System (ADS)

    Braun, Jean

    2016-06-01

    Using a simple solution to the heat conduction equation, I show how, at the end of an orogenic event, the relaxation of isotherms from a syn-orogenic advection-dominated geometry to a post-orogenic conduction-dominated geometry leads to the creation of a thick iso-age crustal layer. Subsequent erosion of this layer yields peculiar age-elevation profiles and detrital age distributions that cannot be easily interpreted using traditional techniques. I illustrate these points by using a simple analytical solution of the heat equation as well as a transient, three-dimensional numerical model. I also demonstrate that the age of the end of an orogenic event is so strongly imprinted in the thermochronological record that it erases most of the information pertaining to the orogenic phase itself and the subsequent isostatically-driven exhumation. The concept is used to explain two thermochronological datasets from the Himalayas and demonstrate that their most likely interpretation involves the sudden interruption of extremely fast exhumation accommodated by movement along the South Tibetan Detachment in the Higher Himalayas around 15 Ma.

  13. Fast optical recording media based on semiconductor nanostructures for image recording and processing

    SciTech Connect

    Kasherininov, P. G. Tomasov, A. A.

    2008-11-15

    Fast optical recording media based on semiconductor nanostructures (CdTe, GaAs) for image recording and processing with a speed to 10{sup 6} cycle/s (which exceeds the speed of known recording media based on metal-insulator-semiconductor-(liquid crystal) (MIS-LC) structures by two to three orders of magnitude), a photosensitivity of 10{sup -2}V/cm{sup 2}, and a spatial resolution of 5-10 (line pairs)/mm are developed. Operating principles of nanostructures as fast optical recording media and methods for reading images recorded in such media are described. Fast optical processors for recording images in incoherent light based on CdTe crystal nanostructures are implemented. The possibility of their application to fabricate image correlators is shown.

  14. 77 FR 48492 - Event Data Recorders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ... vehicle models and avoid disabling legacy EDR systems for a limited number of vehicle models. The agency... the agency's understanding of crash events and safety system performance, thereby potentially... performance requirements. \\1\\ 71 FR 50998. \\2\\ Walk-in van-type trucks or vehicles designed to be...

  15. Frog: The fast & realistic OpenGL event displayer

    NASA Astrophysics Data System (ADS)

    Quertenmont, Loïc

    2010-04-01

    FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy physics experiment. It is suitable to any particular physics experiment or detector design. The code is light (< 3 MB) and fast (browsing time ~ 20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OpenGL[3] and Glut [4] libraries. Moreover, Frog does not require installation of heavy third party libraries for the visualisation. This documents describes the features and principles of Frog version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

  16. Meteoritic event recorded in Antarctic ice

    SciTech Connect

    Harvey, R.P.; Dunbar, N.W.; McIntosh, W.C.; Esser, R.P.; Nishiizumi, Kuni; Taylor, S.; Caffee, M.W.

    1998-07-01

    During systematic sampling of volcanic ash (tephra) layers at a well-known Antarctic meteorite collection site (the Allan Hills main ice field), a band of unusually dark and rounded (many spheroidal) particles was discovered. This debris layer (BIT-58) extends parallel to the stratigraphy of the ice established from the tephra bands, apparently marking a single depositional event. The shapes, internal texture, major element composition, and levels of cosmogenic nuclides of particles from within BIT-58 all strongly suggest that this material represents ablation debris from the passage of a large H-group ordinary chondrite. Preliminary cosmogenic isotope dating suggests an age of 2.8 Ma, implying that the East Antarctic ice sheet has been stable since that time. The relationship of the Bit-58 layer to known impact events is not clear.

  17. Late Eocene impact events recorded in deep-sea sediments

    NASA Technical Reports Server (NTRS)

    Glass, B. P.

    1988-01-01

    Raup and Sepkoski proposed that mass extinctions have occurred every 26 Myr during the last 250 Myr. In order to explain this 26 Myr periodicity, it was proposed that the mass extinctions were caused by periodic increases in cometary impacts. One method to test this hypothesis is to determine if there were periodic increases in impact events (based on crater ages) that correlate with mass extinctions. A way to test the hypothesis that mass extinctions were caused by periodic increases in impact cratering is to look for evidence of impact events in deep-sea deposits. This method allows direct observation of the temporal relationship between impact events and extinctions as recorded in the sedimentary record. There is evidence in the deep-sea record for two (possibly three) impact events in the late Eocene. The younger event, represented by the North American microtektite layer, is not associated with an Ir anomaly. The older event, defined by the cpx spherule layer, is associated with an Ir anomaly. However, neither of the two impact events recorded in late Eocene deposits appears to be associated with an unusual number of extinctions. Thus there is little evidence in the deep-sea record for an impact-related mass extinction in the late Eocene.

  18. Limb Event Brightenings and Fast Ejection Using IRIS Mission Observations

    NASA Astrophysics Data System (ADS)

    Tavabi, E.; Koutchmy, S.; Golub, L.

    2015-10-01

    The Interface Region Imaging Spectrograph (IRIS) of the recently commissioned NASA small explorer mission provides significantly more complete and higher resolution spectral coverage of the dynamical conditions inside the chromosphere and transition region (TR) than has been available ever before. High temporal, spatial (0.3'') and spectral resolution observations from the ultraviolet IRIS spectra near the solar limb reveal high-energy limb event brightenings (LEBs) at low chromospheric heights at about 1 Mm above the limb. They can be characterized as explosive events producing jets. We selected two events showing spectra of a confined eruption just off or near the quiet-Sun limb, the jet part showing obvious moving material with short-duration large Doppler shifts in three directions that were identified as macrospicules on slit-jaw (SJ) images in Si iv and He ii 304 Å. The events were analyzed from a sequence of very close rasters taken near the central meridian and the South Pole limb. We analyzed the processed SJ images and the simultaneously observed fast spectral sequences, which have large Doppler shifts, with a pair of redshifted elements together with a faster blueshifted element from almost the same position. Shifts correspond to velocities of up to 100 km s^{-1} in projection on the plane of the sky. Erupting spicules and macrospicules from these regions are visible in images taken before and after the spectra. The cool low first ionization potential (FIP) element simultaneous line emissions of the Mg ii h and k resonance lines do not clearly show a similar signature because of optical thickness effects, but the Si iv broadband SJ images do. The bidirectional plasma jets ejected from a small reconnection site are interpreted to be the result of coronal loop-loop interactions that lead to reconnection in nearby sites.

  19. Synaptic events that generate fast oscillations in piriform cortex.

    PubMed

    Ketchum, K L; Haberly, L B

    1993-09-01

    Prominent, odor-evoked, fast (40-60 Hz) oscillations have been reported in the olfactory bulb and piriform (primary olfactory) cortex of both awake-behaving and anesthetized animals. The present study used current source-density analysis to examine the origin of the fast oscillations evoked by single weak shocks to afferent fibers. These shock-evoked oscillations closely resemble those evoked by odor. The results revealed that each cycle of the oscillatory field potential was generated by a stereotyped series of membrane currents similar to those previously characterized in the nonoscillatory response to strong afferent fiber shocks. Each cycle began with a strong inward current in layer la identified as an EPSC mediated by afferent fibers in distal apical dendrites of pyramidal cells. This afferent input was followed by a strong inward current in layer Ib identified as an EPSC mediated by intrinsic association fibers in middle apical dendritic segments. These excitatory events were followed by a smaller inward current at the depth of pyramidal cell somata (layers II and superficial III) that may be the depolarizing Cl(-)-mediated IPSC previously identified in the strong-shock response. Based on an analysis of the timing of the EPSCs it was concluded that the weak shock-evoked oscillation is generated in the olfactory bulb and that the resulting periodic activity in afferent fibers drives the oscillation in the piriform cortex.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8366356

  20. Ultra fast all-optical fiber pressure sensor for blast event evaluation

    NASA Astrophysics Data System (ADS)

    Wu, Nan; Wang, Wenhui; Tian, Ye; Niezrecki, Christopher; Wang, Xingwei

    2011-05-01

    Traumatic brain injury (TBI) is a great potential threat to soldiers who are exposed to explosions or athletes who receive cranial impacts. Protecting people from TBI has recently attracted a significant amount of attention due to recent military operations in the Middle East. Recording pressure transient data in a blast event is very critical to the understanding of the effects of blast events on TBI. However, due to the fast change of the pressure during blast events, very few sensors have the capability to effectively track the dynamic pressure transients. This paper reports an ultra fast, miniature and all-optical fiber pressure sensor which could be mounted at different locations of a helmet to measure the fast changing pressure simultaneously. The sensor is based on Fabry-Perot (FP) principle. The end face of the fiber is wet etched. A well controlled thickness silicon dioxide diaphragm is thermal bonded on the end face to form an FP cavity. A shock tube test was conducted at Natick Soldier Research Development and Engineering Center, where the sensors were mounted in a shock tube side by side with a reference sensor to measure the rapidly changing pressure. The results of the test demonstrated that the sensor developed had an improved rise time (shorter than 0.4 μs) when compared to a commercially available reference sensor.

  1. 10,000 yr record of extreme hydrologic events

    SciTech Connect

    Brown, S.L.; Bierman, P.R.; Lini, A.; Southon, J.

    2000-04-01

    Well-dated lacustrine sediments provide a hydrologic record indicating that the frequency and magnitude of runoff events, and by inference, storms, have varied over the past 10 k.y. in northern New England. The authors used five sediment cores and radiocarbon dating to develop a chronology of Holocene hydrologic events for the Ritterbush Pond basin, northern Vermont. Chemical and physical analyses allow them to identify 52 distinct layers of predominantly inorganic sediment that represent terrestrially derived material delivered to the pond by runoff events. The thickness of some layers suggests hydrologic events at least equal in size to, and probably much larger than, any storm or flood recorded during nearly 300 yr of written regional history. Layer thickness and frequency and, by analogy, storm size and recurrence, change through the Holocene. The largest events occurred 2620, 6840, and 9440 calibrated {sup 14}C years before present (cal {sup 14}C yr B.P.). The most frequent hydrologic events occurred in three periods: 1,750 to 2,620, 6,330 to 6,840, and > 8,600 cal yr B.P. The recurrence interval of layer deposition during stormy periods averages 130 {+-} 100 cal yr, whereas the recurrence interval during less stormy periods is longer, 270 {+-} 170 cal yr. The Ritterbush Pond event record illustrates the potential of inorganic lacustrine sediment to serve as a proxy record for estimating paleoflood frequency and deciphering climate change.

  2. Fast, Deep-Record-Length, Fiber-Coupled Photodiode Imaging Array for Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    Brockington, Samuel; Case, Andrew; Witherspoon, F. Douglas

    2015-11-01

    HyperV Technologies has been developing an imaging diagnostic comprised of an array of fast, low-cost, long-record-length, fiber-optically-coupled photodiode channels to investigate plasma dynamics and other fast, bright events. By coupling an imaging fiber bundle to a bank of amplified photodiode channels, imagers and streak imagers can be constructed. By interfacing analog photodiode systems directly to commercial analog-to-digital converters and modern memory chips, a scalable solution for 100 to 1000 pixel systems with 14 bit resolution and record-lengths of 128k frames has been developed. HyperV is applying these techniques to construct a prototype 1000 Pixel framing camera with up to 100 Msamples/sec rate and 10 to 14 bit depth. Preliminary experimental results as well as future plans will be discussed. Work supported by USDOE Phase 2 SBIR Grant DE-SC0009492.

  3. Fast, Deep-Record-Length, Fiber-Coupled Photodiode Imaging Array for Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    Brockington, Samuel; Case, Andrew; Witherspoon, F. Douglas

    2014-10-01

    HyperV Technologies has been developing an imaging diagnostic comprised of an array of fast, low-cost, long-record-length, fiber-optically-coupled photodiode channels to investigate plasma dynamics and other fast, bright events. By coupling an imaging fiber bundle to a bank of amplified photodiode channels, imagers and streak imagers of 100 to 1000 pixels can be constructed. By interfacing analog photodiode systems directly to commercial analog-to-digital converters and modern memory chips, a prototype 100 pixel array with an extremely deep record length (128 k points at 20 Msamples/s) and 10 bit pixel resolution has already been achieved. HyperV now seeks to extend these techniques to construct a prototype 1000 Pixel framing camera with up to 100 Msamples/sec rate and 10 to 12 bit depth. Preliminary experimental results as well as Phase 2 plans will be discussed. Work supported by USDOE Phase 2 SBIR Grant DE-SC0009492.

  4. Wireless event-recording device with identification codes

    NASA Technical Reports Server (NTRS)

    Watters, David G. (Inventor); Huestis, David L. (Inventor); Bahr, Alfred J. (Inventor)

    2004-01-01

    A wireless recording device can be interrogated to determine its identity and its state. The state indicates whether a particular physical or chemical event has taken place. In effect, the physical or chemical event is recorded by the device. The identity of the device allows it to be distinguished from a number of similar devices. Thus the sensor device may be used in an array of devices that can be probed by a wireless interrogation unit. The device tells the interrogator who it is and what state it is in. The interrogator can thus easily identify particular items in an array that have reached a particular condition.

  5. Public support for restrictions on fast food company sponsorship of community events.

    PubMed

    Pettigrew, Simone; Pescud, Melanie; Rosenberg, Michael; Ferguson, Renee; Houghton, Stephen

    2012-01-01

    This study investigated community attitudes to fast food companies' sponsorship of community events. The aim was to inform future efforts to introduce greater restrictions on these marketing activities to reduce child obesity. While previous research has focused on the sponsorship of sporting events, the present study included all community events and gauged public support for fast food company sponsorships in general as well as specific sponsorship activities such as securing event naming rights, advertising on event premises, and distributing free items to children in the form of food and redeemable vouchers. A large and diverse sample of Western Australian adults (n=2,005) responded to a community attitudes telephone survey that included questions relating to event sponsorship. Almost half of the respondents reported that the promotion of fast foods is inappropriate at community events, and only a third considered it appropriate at events where children are likely to be present. Around two-thirds agreed that promoting fast foods at such events sends contradictory messages to children and just a quarter of respondents considered it acceptable for free fast food to be distributed at events or for children to be rewarded for participation with fast food vouchers. The results suggest that efforts to reduce child obesity that involve restrictions on the sponsorship of community events by organisations promoting unhealthy foods may be supported by a substantial proportion of the population. PMID:23017320

  6. A diary after dinner: How the time of event recording influences later accessibility of diary events.

    PubMed

    Szőllősi, Ágnes; Keresztes, Attila; Conway, Martin A; Racsmány, Mihály

    2015-01-01

    Recording the events of a day in a diary may help improve their later accessibility. An interesting question is whether improvements in long-term accessibility will be greater if the diary is completed at the end of the day, or after a period of sleep, the following morning. We investigated this question using an internet-based diary method. On each of five days, participants (n = 109) recorded autobiographical memories for that day or for the previous day. Recording took place either in the morning or in the evening. Following a 30-day retention interval, the diary events were free recalled. We found that participants who recorded their memories in the evening before sleep had best memory performance. These results suggest that the time of reactivation and recording of recent autobiographical events has a significant effect on the later accessibility of those diary events. We discuss our results in the light of related findings that show a beneficial effect of reduced interference during sleep on memory consolidation and reconsolidation. PMID:26088958

  7. An ultra-fast fiber optic pressure sensor for blast event measurements

    NASA Astrophysics Data System (ADS)

    Wu, Nan; Zou, Xiaotian; Tian, Ye; Fitek, John; Maffeo, Michael; Niezrecki, Christopher; Chen, Julie; Wang, Xingwei

    2012-05-01

    Soldiers who are exposed to explosions are at risk of suffering traumatic brain injury (TBI). Since the causal relationship between a blast and TBI is poorly understood, it is critical to have sensors that can accurately quantify the blast dynamics and resulting wave propagation through a helmet and skull that are imparted onto and inside the brain. To help quantify the cause of TBI, it is important to record transient pressure data during a blast event. However, very few sensors feature the capabilities of tracking the dynamic pressure transients due to the rapid change of the pressure during blast events, while not interfering with the physical material layers or wave propagation. In order to measure the pressure transients efficiently, a pressure sensor should have a high resonant frequency and a high spatial resolution. This paper describes an ultra-fast fiber optic pressure sensor based on the Fabry-Perot principle for the application of measuring the rapid pressure changes in a blast event. A shock tube experiment performed in US Army Natick Soldier Research, Development and Engineering Center has demonstrated that the resonant frequency of the sensor is 4.12 MHz, which is relatively close to the designed theoretical value of 4.113 MHz. Moreover, the experiment illustrated that the sensor has a rise time of 120 ns, which demonstrates that the sensor is capable of observing the dynamics of the pressure transient during a blast event.

  8. Comparing Event-records of cryospheric change to high-resolution climate records

    NASA Astrophysics Data System (ADS)

    Schaefer, J. M.; Denton, G.; Putnam, A. E.; Kaplan, M. R.; Barrell, D.; Schluechter, C.; Rupper, S.; Finkel, R. C.; Schwartz, R.

    2012-12-01

    Evaluation of ongoing Cryospheric Change is a forefront challenge of earth sciences, because it directly impacts societies by sea level rise and changing river run-off pattern in densely populated areas. Robust predictions of future cryospheric change require quantitative understanding of the coupling between the climate and cryosphere systems. One promising approach to do so is to compare paleo-climate and paleo-cryosphere records. However, the terrestrial cryospheric record, including morphologies such as moraines and proglacial bedrock, represents an 'event record' that is by definition non-continuous. The most important climate proxy records such as polar ice-cores, marine sediment cores and speleothems are continuous, high-resolution proxy records. Meaningful comparison of the two requires detailed and accurate chronologies of the cryospheric record. Over the last years, the sensitivity of the method of surface exposure dating has considerably improved, increasing precision and size of data set. Now, we are in the position to compare, geomorphic records of former glacier and ice-sheet positions with continuous and high resolution climate records, and in turn, perform the experiment described above. Here we will compare extensive mountain glacier moraine chronologies from both hemispheres with relevant climate records, including tree-ring records, ice core proxy and gas records, and marine sediment records. We show that glacier fluctuations in New Zealand show remarkable general consistency to summer temperature and atmospheric greenhouse gas records, but also find second order distinctions between different glacier fluctuation records and the climate records on shorter time-scales. We focus on the time periods of (i) the last ice age termination and subsequent deglaciation (20-10 ka) and (ii) the late Holocene, including the last millennium and the Little Ice Age Period (CE 1300-1850).

  9. Exupery volcano fast response system - The event detection and waveform classification system

    NASA Astrophysics Data System (ADS)

    Hammer, Conny; Ohrnberger, Matthias

    2010-05-01

    Volcanic eruptions are often preceded by seismic activity which can be used to quantify the volcanic activity since the number and the size of certain types of seismic events usually increase before periods of volcanic crisis. The implementation of an automatic detection and classification system for seismic signals of volcanic origin allows not only for the processing of large amounts of data in short time, but also provides consistent and time-invariant results. Here, we have developed a system based upon a combination of different methods. To enable a first robust event detection in the continuous data stream different modules are implemented in the real time system Earthworm which is widely distributed in active volcano monitoring observatories worldwide. Among those software modules are classical trigger algorithm like STA/LTA and cross-correlation master event matching which is also used to detect different classes of signals. Furthermore an additional module is implemented in the real time system to compute continuous activity parameters which are also used to quantify the volcanic activity. Most automatic classification systems need a sufficiently large pre-classified data set for training the system. However in case of a volcanic crisis we are often confronted with a lack of training data due to insufficient prior observations because prior data acquisition might be carried out with different equipment at a low number of sites and due to the imminent crisis there might be no time for the time-consuming and tedious process of preparing a training data set. For this reason we have developed a novel seismic event spotting technique in order to be less dependent on the existence of previously acquired data bases of event classes. One main goal is therefore to provide observatory staff with a robust event classification based on a minimum number of reference waveforms. By using a "learning-while-recording" approach we are allowing for the fast build-up of a

  10. Different event-related patterns of gamma-band power in brain waves of fast- and slow-reacting subjects.

    PubMed Central

    Jokeit, H; Makeig, S

    1994-01-01

    Fast- and slow-reacting subjects exhibit different patterns of gamma-band electroencephalogram (EEG) activity when responding as quickly as possible to auditory stimuli. This result appears to confirm long-standing speculations of Wundt that fast- and slow-reacting subjects produce speeded reactions in different ways and demonstrates that analysis of event-related changes in the amplitude of EEG activity recorded from the human scalp can reveal information about event-related brain processes unavailable using event-related potential measures. Time-varying spectral power in a selected (35- to 43-Hz) gamma frequency band was averaged across trials in two experimental conditions: passive listening and speeded reacting to binaural clicks, forming 40-Hz event-related spectral responses. Factor analysis of between-subject event-related spectral response differences split subjects into two near-equal groups composed of faster- and slower-reacting subjects. In faster-reacting subjects, 40-Hz power peaked near 200 ms and 400 ms poststimulus in the react condition, whereas in slower-reacting subjects, 40-Hz power just before stimulus delivery was larger in the react condition. These group differences were preserved in separate averages of relatively long and short reaction-time epochs for each group. gamma-band (20-60 Hz)-filtered event-related potential response averages did not differ between the two groups or conditions. Because of this and because gamma-band power in the auditory event-related potential is small compared with the EEG, the observed event-related spectral response features must represent gamma-band EEG activity reliably induced by, but not phase-locked to, experimental stimuli or events. PMID:8022783

  11. Impact of flood events on lacustrine carbonate isotope records

    NASA Astrophysics Data System (ADS)

    Kämpf, Lucas; Plessen, Birgit; Lauterbach, Stefan; Nantke, Carla; Meyer, Hanno; Chapligin, Bernhard; Höllerer, Hannes; Brauer, Achim

    2016-04-01

    Stable oxygen (δ 18O) and carbon (δ 13C) isotope compositions of lacustrine carbonates are among the most frequently used proxies in palaeolimnological / -environmental studies. Stable isotope analyses are often carried out on bulk carbonate samples, which are prone to contamination with detrital carbonates, transported into the lake by runoff processes and carrying the isotopic signal of catchment rocks, thus hampering the interpretation of the data in terms of past climatic and/or environmental changes. Despite the awareness of a likely detrital bias, the degree of contamination in most cases remains unknown and discrete contaminated samples undetected due to a lack of methods to disentangle endogenic and detrital carbonates in sediment records. To address this issue and provide more comprehensive insights into effects of flood-related detrital input on the bulk carbonate isotopic composition, we conducted stable isotope measurements on sediments trapped on a 3-12 day basis over a three-year period (January 2011 to November 2013) at two locations in pre-Alpine Lake Mondsee, close to the inflow of the main tributary and in the deepest part of the lake basin. Lake Mondsee was chosen for the monitoring since the pelagic sediments are annually laminated consisting of couplets of light calcite layers and dark layers made up by a mixture of detrital clastic and organic matter. Maximum calcite flux rates >1.5 g m2 d-1 were trapped between May and September, indicating the seasonal endogenic precipitation of calcite crystals. The comparison of the δ 18O composition of trapped carbonates, rain and epilimnion lake water revealed equilibrium calcite precipitation, allowing us to infer purely endogenic δ 18O (-9 to -11.3‰ VPDB) and δ 13C values (-6 to -9‰ VPDB) throughout the summer season. The endogenic calcite precipitation was interrupted by 14 peaks in carbonate flux (4 to 175 g m2 d-1) triggered by runoff events of different magnitudes (10-110 m3 s-1 peak

  12. Ca2+ Release Events in Cardiac Myocytes Up Close: Insights from Fast Confocal Imaging

    PubMed Central

    Shkryl, Vyacheslav M.; Blatter, Lothar A.

    2013-01-01

    The spatio-temporal properties of Ca2+ transients during excitation-contraction coupling and elementary Ca2+ release events (Ca2+ sparks) were studied in atrial and ventricular myocytes with ultra-fast confocal microscopy using a Zeiss LSM 5 LIVE system that allows sampling rates of up to 60 kHz. Ca2+ sparks which originated from subsarcolemmal junctional sarcoplasmic reticulum (j-SR) release sites in atrial myocytes were anisotropic and elongated in the longitudinal direction of the cell. Ca2+ sparks in atrial cells originating from non-junctional SR and in ventricular myocytes were symmetrical. Ca2+ spark recording in line scan mode at 40,000 lines/s uncovered step-like increases of [Ca2+]i. 2-D imaging of Ca2+ transients revealed an asynchronous activation of release sites and allowed the sequential recording of Ca2+ entry through surface membrane Ca2+ channels and subsequent activation of Ca2+-induced Ca2+ release. With a latency of 2.5 ms after application of an electrical stimulus, Ca2+ entry could be detected that was followed by SR Ca2+ release after an additional 3 ms delay. Maximum Ca2+ release was observed 4 ms after the beginning of release. The timing of Ca2+ entry and release was confirmed by simultaneous [Ca2+]i and membrane current measurements using the whole cell voltage-clamp technique. In atrial cells activation of discrete individual release sites of the j-SR led to spatially restricted Ca2+ release events that fused into a peripheral ring of elevated [Ca2+]i that subsequently propagated in a wave-like fashion towards the center of the cell. In ventricular myocytes asynchronous Ca2+ release signals from discrete sites with no preferential subcellular location preceded the whole-cell Ca2+ transient. In summary, ultra-fast confocal imaging allows investigation of Ca2+ signals with a time resolution similar to patch clamp technique, however in a less invasive fashion. PMID:23637847

  13. Analysis of Continuous Microseismic Recordings: Resonance Frequencies and Unconventional Events

    NASA Astrophysics Data System (ADS)

    Tary, J.; van der Baan, M.

    2012-12-01

    Hydrofracture experiments, where fluids and proppant are injected into reservoirs to create fractures and enhance oil recovery, are often monitored using microseismic recordings. The total stimulated volume is then estimated by the size of the cloud of induced micro-earthquakes. This implies that only brittle failure should occur inside reservoirs during the fracturing. Yet, this assumption may not be correct, as the total energy injected into the system is orders of magnitude larger than the total energy associated with brittle failure. Instead of using only triggered events, it has been shown recently that the frequency content of continuous recordings may also provide information on the deformations occurring inside reservoirs. Here, we use different kinds of time-frequency transforms to track the presence of resonance frequencies. We analyze different data sets using regular, long-period and broadband geophones. The resonance frequencies observed are mainly included in the frequency band of 5-60 Hz. We systematically examine first the possible causes of resonance frequencies, dividing them into source, path and receiver effects. We then conclude that some of the observed frequency bands likely result from source effects. The resonance frequencies could be produced by either interconnected fluid-filled fractures in the order of tens of meters, or by small repetitive events occurring at a characteristic periodicity. Still, other mechanisms may occur or be predominant during reservoir fracturing, depending on the lithology as well as the pressure and temperature conditions at depth. During one experiment, both regular micro-earthquakes, long-period long-duration events (LPLD) and resonance frequencies are observed. The lower part of the frequency band of these resonance frequencies (5-30 Hz) overlaps with the anticipated frequencies of observed LPLDs in other experiments (<50 Hz). The exact origin of both resonance frequencies and LPLDs is still under debate

  14. Fast Stimulus Artifact Recovery in a Multichannel Neural Recording System

    PubMed Central

    Schoenecker, Matthew C.; Bonham, Ben H.

    2010-01-01

    We describe a 32-channel recording system and software artifact blanking technique for recording neuronal responses to high-rate electrical stimulation. Each recording channel recovers from biphasic full-scale-input pulses (1.5-V) in less than 80 μs. Artifacts are blanked online in software, allowing flexibility in the choice of blanking period and the possibility of recovering neural data occurring simultaneously with non-saturating artifacts. The system has been used in-vivo to record central neuronal responses to intracochlear electrical stimulation at 2000 pulses per second. Simplicity of the hardware design makes the technique well suited to an implantable multi-channel recording system. PMID:20559458

  15. Adaptive sparse signal processing of satellite-based radio frequency (RF) recordings of lightning events

    NASA Astrophysics Data System (ADS)

    Moody, Daniela I.; Smith, David A.

    2014-05-01

    Ongoing research at Los Alamos National Laboratory studies the Earth's radio frequency (RF) background utilizing satellite-based RF observations of terrestrial lightning. Such impulsive events are dispersed through the ionosphere and appear as broadband nonlinear chirps at a receiver on-orbit. They occur in the presence of additive noise and structured clutter, making their classification challenging. The Fast On-orbit Recording of Transient Events (FORTE) satellite provided a rich RF lightning database. Application of modern pattern recognition techniques to this database may further lightning research in the scientific community, and potentially improve on-orbit processing and event discrimination capabilities for future satellite payloads. Conventional feature extraction techniques using analytical dictionaries, such as a short-time Fourier basis or wavelets, are not comprehensively suitable for analyzing the broadband RF pulses under consideration here. We explore an alternative approach based on non-analytical dictionaries learned directly from data, and extend two dictionary learning algorithms, K-SVD and Hebbian, for use with satellite RF data. Both algorithms allow us to learn features without relying on analytical constraints or additional knowledge about the expected signal characteristics. We then use a pursuit search over the learned dictionaries to generate sparse classification features, and discuss their performance in terms of event classification. We also use principal component analysis to analyze and compare the respective learned dictionary spaces to the real data space.

  16. The 17 January 2005 Complex Solar Radio Event Associated with Interacting Fast Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Hillaris, A.; Malandraki, O.; Klein, K.-L.; Preka-Papadema, P.; Moussas, X.; Bouratzis, C.; Mitsakou, E.; Tsitsipis, P.; Kontogeorgos, A.

    2011-11-01

    On 17 January 2005 two fast coronal mass ejections were recorded in close succession during two distinct episodes of a 3B/X3.8 flare. Both were accompanied by metre-to-kilometre type-III groups tracing energetic electrons that escape into the interplanetary space and by decametre-to-hectometre type-II bursts attributed to CME-driven shock waves. A peculiar type-III burst group was observed below 600 kHz 1.5 hours after the second type-III group. It occurred without any simultaneous activity at higher frequencies, around the time when the two CMEs were expected to interact. We associate this emission with the interaction of the CMEs at heliocentric distances of about 25 R ⊙. Near-relativistic electrons observed by the EPAM experiment onboard ACE near 1 AU revealed successive particle releases that can be associated with the two flare/CME events and the low-frequency type-III burst at the time of CME interaction. We compare the pros and cons of shock acceleration and acceleration in the course of magnetic reconnection for the escaping electron beams revealed by the type-III bursts and for the electrons measured in situ.

  17. The 17 January 2005 Complex Solar Radio Event Associated with Interacting Fast Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Hillaris, A.; Malandraki, O.; Klein, K.-L.; Preka-Papadema, P.; Moussas, X.; Bouratzis, C.; Mitsakou, E.; Tsitsipis, P.; Kontogeorgos, A.

    On 17 January 2005 two fast coronal mass ejections were recorded in close succession during two distinct episodes of a 3B/X3.8 flare. Both were accompanied by metre-to-kilometre type-III groups tracing energetic electrons that escape into the interplanetary space and by decametre-to-hectometre type-II bursts attributed to CME-driven shock waves. A peculiar type-III burst group was observed below 600 kHz 1.5 hours after the second type-III group. It occurred without any simultaneous activity at higher frequencies, around the time when the two CMEs were expected to interact. We associate this emission with the interaction of the CMEs at heliocentric distances of about 25 R ⊙. Near-relativistic electrons observed by the EPAM experiment onboard ACE near 1 AU revealed successive particle releases that can be associated with the two flare/CME events and the low-frequency type-III burst at the time of CME interaction. We compare the pros and cons of shock acceleration and acceleration in the course of magnetic reconnection for the escaping electron beams revealed by the type-III bursts and for the electrons measured in situ.

  18. A study of the first solar proton event of current solar cycle recorded by satellites and ground based detectors

    NASA Astrophysics Data System (ADS)

    Gerontidou, M.; Mavromichalaki, H.; Plainaki, C.; Belov, A.; Eroshenko, E.; Yanke, V.; Laurenza, M.; Storini, M.

    2013-09-01

    On 2012, May 17 the GOES satellites recorded a great and simultaneous increase on proton flux in different energy channels thereby producing a solar proton event (SPE). These protons had enough energy to be recorded by the ground based worldwide network of neutron monitors thereby producing the first ground level enhancement of solar cosmic rays (GLE71) of the current solar cycle. In this work a combined study of the this solar proton event, as it is recorded by GOES satellites as well as by the ground based network of Neutron monitors is presented. On 2012, May 17 at 02:10 UTC the GOES spacecraft recorded a fast rise in the flux of solar protons, followed by a slower decay, which was still ongoing on 18 May 2012. Several solar proton events stronger than that of 17 May 2012 were detected by GOES in January and March 2012. This event of 17 May extended to much higher energies than those earlier ones, but was weaker at lower energies. Through this research an attempt to understand the reason for these differences is performed. Additionally, a first attempt to derive the characteristics of this recent proton event, by applying an updated version of the NMBANGLE PPOLA model, already used for modeling past GLEs (e.g. GLE70 ) is presented. The special characteristics of this event with respect to the result of NMBANGLE POLLA model can provide useful information not only about the solar source that triggered this SPE, but also its special impact at interplanetary space.

  19. Demanding response time requirements on coherent receivers due to fast polarization rotations caused by lightning events.

    PubMed

    Krummrich, Peter M; Ronnenberg, David; Schairer, Wolfgang; Wienold, Daniel; Jenau, Frank; Herrmann, Maximilian

    2016-05-30

    Lightning events can cause fast polarization rotations and phase changes in optical transmission fibers due to strong electrical currents and magnetic fields. Whereas these are unlikely to affect legacy transmission systems with direct detection, different mechanisms have to be considered in systems with local oscillator based coherent receivers and digital signal processing. A theoretical analysis reveals that lightning events can result in polarization rotations with speeds as fast as a few hundred kRad/s. We discuss possible mechanisms how such lightning events can affect coherent receivers with digital signal processing. In experimental investigations with a high current pulse generator and transponder prototypes, we observed post FEC errors after polarization rotation events which can be expected from lightning strikes. PMID:27410158

  20. Demanding response time requirements on coherent receivers due to fast polarization rotations caused by lightning events.

    PubMed

    Krummrich, Peter M; Ronnenberg, David; Schairer, Wolfgang; Wienold, Daniel; Jenau, Frank; Herrmann, Maximilian

    2016-05-30

    Lightning events can cause fast polarization rotations and phase changes in optical transmission fibers due to strong electrical currents and magnetic fields. Whereas these are unlikely to affect legacy transmission systems with direct detection, different mechanisms have to be considered in systems with local oscillator based coherent receivers and digital signal processing. A theoretical analysis reveals that lightning events can result in polarization rotations with speeds as fast as a few hundred kRad/s. We discuss possible mechanisms how such lightning events can affect coherent receivers with digital signal processing. In experimental investigations with a high current pulse generator and transponder prototypes, we observed post FEC errors after polarization rotation events which can be expected from lightning strikes.

  1. 49 CFR Appendix D to Part 229 - Criteria for Certification of Crashworthy Event Recorder Memory Module

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Recorder Memory Module D Appendix D to Part 229 Transportation Other Regulations Relating to Transportation... Memory Module Section 229.135(b) requires that certain locomotives be equipped with an event recorder that includes a certified crashworthy event recorder memory module. This appendix prescribes...

  2. 49 CFR Appendix D to Part 229 - Criteria for Certification of Crashworthy Event Recorder Memory Module

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Recorder Memory Module D Appendix D to Part 229 Transportation Other Regulations Relating to Transportation... Memory Module Section 229.135(b) requires that certain locomotives be equipped with an event recorder that includes a certified crashworthy event recorder memory module. This appendix prescribes...

  3. 49 CFR Appendix D to Part 229 - Criteria for Certification of Crashworthy Event Recorder Memory Module

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Recorder Memory Module D Appendix D to Part 229 Transportation Other Regulations Relating to Transportation... Memory Module Section 229.135(b) requires that certain locomotives be equipped with an event recorder that includes a certified crashworthy event recorder memory module. This appendix prescribes...

  4. 49 CFR Appendix D to Part 229 - Criteria for Certification of Crashworthy Event Recorder Memory Module

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Recorder Memory Module D Appendix D to Part 229 Transportation Other Regulations Relating to Transportation... Memory Module Section 229.135(b) requires that certain locomotives be equipped with an event recorder that includes a certified crashworthy event recorder memory module. This appendix prescribes...

  5. 49 CFR Appendix D to Part 229 - Criteria for Certification of Crashworthy Event Recorder Memory Module

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Recorder Memory Module D Appendix D to Part 229 Transportation Other Regulations Relating to Transportation... Memory Module Section 229.135(b) requires that certain locomotives be equipped with an event recorder that includes a certified crashworthy event recorder memory module. This appendix prescribes...

  6. LIMITS ON THE EVENT RATES OF FAST RADIO TRANSIENTS FROM THE V-FASTR EXPERIMENT

    SciTech Connect

    Wayth, Randall B.; Tingay, Steven J.; Deller, Adam T.; Brisken, Walter F.; Thompson, David R.; Wagstaff, Kiri L.; Majid, Walid A.

    2012-07-10

    We present the first results from the V-FASTR experiment, a commensal search for fast transient radio bursts using the Very Long Baseline Array (VLBA). V-FASTR is unique in that the widely spaced VLBA antennas provide a discriminant against non-astronomical signals and a mechanism for the localization and identification of events that is not possible with single dishes or short baseline interferometers. Thus, far V-FASTR has accumulated over 1300 hr of observation time with the VLBA, between 90 cm and 3 mm wavelength (327 MHz-86 GHz), providing the first limits on fast transient event rates at high radio frequencies (>1.4 GHz). V-FASTR has blindly detected bright individual pulses from seven known pulsars but has not detected any single-pulse events that would indicate high-redshift impulsive bursts of radio emission. At 1.4 GHz, V-FASTR puts limits on fast transient event rates comparable with the PALFA survey at the Arecibo telescope, but generally at lower sensitivities, and comparable to the 'fly's eye' survey at the Allen Telescope Array, but with less sky coverage. We also illustrate the likely performance of the Phase 1 SKA dish array for an incoherent fast transient search fashioned on V-FASTR.

  7. Limits on the Event Rates of Fast Radio Transients from the V-FASTR Experiment

    NASA Astrophysics Data System (ADS)

    Wayth, Randall B.; Tingay, Steven J.; Deller, Adam T.; Brisken, Walter F.; Thompson, David R.; Wagstaff, Kiri L.; Majid, Walid A.

    2012-07-01

    We present the first results from the V-FASTR experiment, a commensal search for fast transient radio bursts using the Very Long Baseline Array (VLBA). V-FASTR is unique in that the widely spaced VLBA antennas provide a discriminant against non-astronomical signals and a mechanism for the localization and identification of events that is not possible with single dishes or short baseline interferometers. Thus, far V-FASTR has accumulated over 1300 hr of observation time with the VLBA, between 90 cm and 3 mm wavelength (327 MHz-86 GHz), providing the first limits on fast transient event rates at high radio frequencies (>1.4 GHz). V-FASTR has blindly detected bright individual pulses from seven known pulsars but has not detected any single-pulse events that would indicate high-redshift impulsive bursts of radio emission. At 1.4 GHz, V-FASTR puts limits on fast transient event rates comparable with the PALFA survey at the Arecibo telescope, but generally at lower sensitivities, and comparable to the "fly's eye" survey at the Allen Telescope Array, but with less sky coverage. We also illustrate the likely performance of the Phase 1 SKA dish array for an incoherent fast transient search fashioned on V-FASTR.

  8. Safety design approach for external events in Japan sodium-cooled fast reactor

    SciTech Connect

    Yamano, H.; Kubo, S.; Tani, A.; Nishino, H.; Sakai, T.

    2012-07-01

    This paper describes a safety design approach for external events in the design study of Japan sodium-cooled fast reactor. An emphasis is introduction of a design extension external condition (DEEC). In addition to seismic design, other external events such as tsunami, strong wind, abnormal temperature, etc. were addressed in this study. From a wide variety of external events consisting of natural hazards and human-induced ones, a screening method was developed in terms of siting, consequence, frequency to select representative events. Design approaches for these events were categorized on the probabilistic, statistical and deterministic basis. External hazard conditions were considered mainly for DEECs. In the probabilistic approach, the DEECs of earthquake, tsunami and strong wind were defined as 1/10 of exceedance probability of the external design bases. The other representative DEECs were also defined based on statistical or deterministic approaches. (authors)

  9. Fast-track extreme event attribution: How fast can we disentangle thermodynamic (forced) and dynamic (internal) contributions?

    NASA Astrophysics Data System (ADS)

    Haustein, Karsten; Otto, Friederike; Uhe, Peter; Allen, Myles; Cullen, Heidi

    2016-04-01

    provide sufficient guidance to determine the dynamic contribution to the event on the basis of monthly mean values. No such link can be made (North Atlantic/Western Europe region) for shorter time-scales, unless the observed state of the circulation is taken as reference for the model analysis (e.g. Christidis et al. 2014). We present results from our most recent attribution analysis for the December 2015 UK floods (Storm Desmond and Eva), during which we find a robust teleconnection link between Pacific SSTs and North Atlantic Jetstream anomalies. This is true for both experiments, with forecast and observed SSTs. We propose a fast and simple analysis method based on the comparison of current climatological circulation patterns with actual and natural conditions. Alternative methods are discussed and analysed regarding their potential for fast-track attribution of the role of dynamics. Also, we briefly revisit the issue of internal vs forced dynamic contributions.

  10. Controls on Flood Event Frequencies Recorded in Stalagmites from Cave KNI-51, Australian Tropics

    NASA Astrophysics Data System (ADS)

    Denniston, Rhawn; Gonzales, Angelique; Villarini, Gabriele; Polyak, Victor; Asmerom, Yemane; Wanamaker, Alan, Jr.; Lachniet, Matthew; Ummenhofer, Caroline; Cugley, John; Woods, David; Humphreys, William

    2016-04-01

    Extreme rainfall events in the central Australia tropics are largely driven by tropical cyclones and the Australian summer monsoon, both of which are sensitive to external forcing. To better understand baseline variability in extreme rainfall, we produced a record of cave flooding events spanning the last two millennia from a suite of precisely-dated and fast-growing aragonite stalagmites from cave KNI-51 (Denniston et al., 2015, PNAS, 112, 4576). During cave flooding events, sediment deposited on stalagmite surfaces becomes preserved within the stalagmite when floodwaters recede and stalagmite growth resumes. Ages of individual flood events are determined using growth models constructed from linear interpolation of 230Th-dated intervals of stalagmite carbonate (2 s.d. errors of ±1-30 yr in most cases). The robustness of this stalagmite flood record was tested, in part, by comparing accumulations of sediment layers in coeval stalagmites. Absolute values and temporal trends in flood recurrence rates were generally quite similar between stalagmites, arguing that each stalagmite was equally sensitive to flood events. We have now extended this cave flooding record back to 3600 yr BP using three additional stalagmites, each of which contains multi-decadal to centennial variations in flood frequency. The longest duration (1000 yr) and tallest (1.1m) of these stalagmites, KNI-51-7, is marked by a secular trend toward reduced flood occurrence rates, with the 30 yr running mean of floods/yr reaching 0.0, a value lower than in any other of the other nine samples analyzed in this study. However, KNI-51-N, which overlaps with KNI-51-7 for 300 yr, contains nearly identical sub-centennial variations to KNI-51-7 but KNI-51-N does not trend toward lower values. We argue that the decreasing average number of flood events with time in KNI-51-7 is a result of the stalagmite having grown above average flood height, thereby restricting its ability to record more frequent, smaller

  11. Temperature variability and early clustering of record-breaking events

    NASA Astrophysics Data System (ADS)

    Anderson, Amalia; Kostinski, Alex

    2016-05-01

    As the number of climatological studies using record-breaking statistics is growing rapidly, understanding the sensitivity of the chosen time period becomes essential. To that end, here we examine the evolving variability of monthly mean temperatures and its dependence on beginning and final year. Specifically, we use an index, α, based on record-breaking statistics and employing reversibility such that < α>=0 indicates no trend in variability. Generally, < α> has decreased between 1900 and 2013, indicating decreasing variability relative to early decades for stations from the contiguous USA (United States Historical Climatology Network, version 2.5). We find, somewhat surprisingly, that the observed decrease is due to an early excess of records beginning in 1917 (record low value) and 1921 (record high value). While detailed results depend on whether the data is gridded, detrended, etc., the general finding appears remarkably robust and holds globally as well.

  12. Deflections of Fast Coronal Mass Ejections and the Properties of Associated Solar Energetic Particle Events

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Akiyama, S.; Gopalswamy, N.

    2012-01-01

    The onset times and peak intensities of solar energetic particle (SEP) events at Earth have long been thought to be influenced by the open magnetic fields of coronal holes (CHs). The original idea was that a CH lying between the solar SEP source region and the magnetic footpoint of the 1 AU observer would result in a delay in onset and/or a decrease in the peak intensity of that SEP event. Recently, Gopalswamy et al. showed that CHs near coronal mass ejection (CME) source regions can deflect fast CMEs from their expected trajectories in space, explaining the appearance of driverless shocks at 1 AU from CMEs ejected near solar central meridian (CM). This suggests that SEP events originating in CME-driven shocks may show variations attributable to CH deflections of the CME trajectories. Here, we use a CH magnetic force parameter to examine possible effects of CHs on the timing and intensities of 41 observed gradual E approx 20 MeV SEP events with CME source regions within 20 deg. of CM. We find no systematic CH effects on SEP event intensity profiles. Furthermore, we find no correlation between the CME leading-edge measured position angles and SEP event properties, suggesting that the widths of CME-driven shock sources of the SEPs are much larger than the CMEs. Independently of the SEP event properties, we do find evidence for significant CME deflections by CH fields in these events

  13. Record-breaking events during the compressive failure of porous materials

    NASA Astrophysics Data System (ADS)

    Pál, Gergő; Raischel, Frank; Lennartz-Sassinek, Sabine; Kun, Ferenc; Main, Ian G.

    2016-03-01

    An accurate understanding of the interplay between random and deterministic processes in generating extreme events is of critical importance in many fields, from forecasting extreme meteorological events to the catastrophic failure of materials and in the Earth. Here we investigate the statistics of record-breaking events in the time series of crackling noise generated by local rupture events during the compressive failure of porous materials. The events are generated by computer simulations of the uniaxial compression of cylindrical samples in a discrete element model of sedimentary rocks that closely resemble those of real experiments. The number of records grows initially as a decelerating power law of the number of events, followed by an acceleration immediately prior to failure. The distribution of the size and lifetime of records are power laws with relatively low exponents. We demonstrate the existence of a characteristic record rank k*, which separates the two regimes of the time evolution. Up to this rank deceleration occurs due to the effect of random disorder. Record breaking then accelerates towards macroscopic failure, when physical interactions leading to spatial and temporal correlations dominate the location and timing of local ruptures. The size distribution of records of different ranks has a universal form independent of the record rank. Subsequences of events that occur between consecutive records are characterized by a power-law size distribution, with an exponent which decreases as failure is approached. High-rank records are preceded by smaller events of increasing size and waiting time between consecutive events and they are followed by a relaxation process. As a reference, surrogate time series are generated by reshuffling the event times. The record statistics of the uncorrelated surrogates agrees very well with the corresponding predictions of independent identically distributed random variables, which confirms that temporal and spatial

  14. Record-breaking events during the compressive failure of porous materials.

    PubMed

    Pál, Gergő; Raischel, Frank; Lennartz-Sassinek, Sabine; Kun, Ferenc; Main, Ian G

    2016-03-01

    An accurate understanding of the interplay between random and deterministic processes in generating extreme events is of critical importance in many fields, from forecasting extreme meteorological events to the catastrophic failure of materials and in the Earth. Here we investigate the statistics of record-breaking events in the time series of crackling noise generated by local rupture events during the compressive failure of porous materials. The events are generated by computer simulations of the uniaxial compression of cylindrical samples in a discrete element model of sedimentary rocks that closely resemble those of real experiments. The number of records grows initially as a decelerating power law of the number of events, followed by an acceleration immediately prior to failure. The distribution of the size and lifetime of records are power laws with relatively low exponents. We demonstrate the existence of a characteristic record rank k(*), which separates the two regimes of the time evolution. Up to this rank deceleration occurs due to the effect of random disorder. Record breaking then accelerates towards macroscopic failure, when physical interactions leading to spatial and temporal correlations dominate the location and timing of local ruptures. The size distribution of records of different ranks has a universal form independent of the record rank. Subsequences of events that occur between consecutive records are characterized by a power-law size distribution, with an exponent which decreases as failure is approached. High-rank records are preceded by smaller events of increasing size and waiting time between consecutive events and they are followed by a relaxation process. As a reference, surrogate time series are generated by reshuffling the event times. The record statistics of the uncorrelated surrogates agrees very well with the corresponding predictions of independent identically distributed random variables, which confirms that temporal and spatial

  15. Event Management of RFID Data Streams: Fast Moving Consumer Goods Supply Chains

    NASA Astrophysics Data System (ADS)

    Mo, John P. T.; Li, Xue

    Radio Frequency Identification (RFID) is a wireless communication technology that uses radio-frequency waves to transfer information between tagged objects and readers without line of sight. This creates tremendous opportunities for linking real world objects into a world of "Internet of things". Application of RFID to Fast Moving Consumer Goods sector will introduce billions of RFID tags in the world. Almost everything is tagged for tracking and identification purposes. This phenomenon will impose a new challenge not only to the network capacity but also to the scalability of processing of RFID events and data. This chapter uses two national demonstrator projects in Australia as case studies to introduce an event managementframework to process high volume RFID data streams in real time and automatically transform physical RFID observations into business-level events. The model handles various temporal event patterns, both simple and complex, with temporal constraints. The model can be implemented in a data management architecture that allows global RFID item tracking and enables fast, large-scale RFID deployment.

  16. A COMPARISON OF ELEMENTAL ABUNDANCE RATIOS IN SEP EVENTS IN FAST AND SLOW SOLAR WIND REGIONS

    SciTech Connect

    Kahler, S. W.; Tylka, A. J.; Reames, D. V.

    2009-08-10

    The solar energetic (E > 1 MeV nucleon{sup -1}) particles (SEPs) observed in gradual events at 1 AU are assumed to be accelerated by coronal/interplanetary shocks from ambient thermal or suprathermal seed particles. If so, then the elemental abundances of SEPs produced in different solar wind (SW) stream types (transient, fast, and slow) might be systematically distinguished from each other. We look for these differences in SEP energy spectra and in elemental abundance ratios (including Mg/Ne and Fe/C, which compare low/high first ionization potential elements), in a large number of SEP time intervals over the past solar cycle. The SW regions are characterized by the three-component stream classification of Richardson et al. Our survey shows no significant compositional or energy spectral differences in the 5-10 MeV nucleon{sup -1} range for SEP events of different SW stream types. This result extends the earlier finding that SEP events are observed frequently in fast SW streams, although their higher Alfven and SW flow speeds should constrain SEP production by coronal mass ejection-driven shocks in those regions. We discuss the implications of our results for shock seed populations and cross-field propagation.

  17. ANTARES explosion as recorded by the US-ARRAY: an unprecedented ground-truth infrasound event

    NASA Astrophysics Data System (ADS)

    Vergoz, Julien; Millet, Christophe; Le Pichon, Alexis

    2016-04-01

    The 28th October 2014 in Wallops Flight Facility, orbital's Antares launch vehicle failed and heavily exploded onto the launch pad area. At that time, the US transportable array of more than 200 operating stations (all equipped with microbarometers), was located on the east coast of the US and surrounded the accident. A large amount and variety of infrasound phases were observed at some stations, highlighting interesting propagation effects. The variety of recorded signals on such a dense network is unprecedented and offers the opportunity to better understand some propagation features, such as (1) the frequency content changes of stratospheric phases; (2) the dispersion of tropospheric phases propagating over thousands of kilometers within a stable and thin waveguide at fast phase speeds (350m/s) with low attenuation; (3) the non-linear effects associated with slow thermospheric phases (180m/s), especially in terms of shape, amplitude and duration. These 3 points will be addressed, and pieces of interpretations will be given thanks to the different propagation techniques: full waveform modelling (Normal Modes, finite element method), parabolic equation and ray tracing technique. Location issues of such an acoustic event based on tens of infrasound arrival times only will also be shown and discussed.

  18. Temporal-spatial heterogeneity of under-recording of volcanic events in Japan

    NASA Astrophysics Data System (ADS)

    Kiyosugi, Koji

    2016-04-01

    Under-recording of events must be taken into account in estimating recurrence rates of explosive eruptions using volcanic eruption record. In the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database (Crosweller et al., 2012, Brown et al., 2014), Japanese events account for about 39 % of the entire set of eruptive events (Kiyosugi et al., 2015). An analysis of the Japanese eruption events show an inverse correlation between VEI and degree of under-reporting suggesting that even larger VEI eruptions are under-recorded in the Quaternary. For example, 89 % of VEI 4 events, 65-66 % of VEI 5 events, 46-49 % of VEI 6 events and 36-39 % of VEI 7 events are missing from the record at 100 ka, 200 ka, 300 ka, and 500 ka, respectively (Kiyosugi et al., 2015). Comparison of frequencies of Japanese and global eruptions suggests that under-recording of the global database is 7.9-8.7 times larger than in the Japanese dataset (Kiyosugi et al., 2015). In addition to the analysis of the entire Japanese eruption events, temporal-spatial heterogeneity of the dataset must be considered in modeling the under-recording of events. The main mechanisms of under-recording are absence of historical records, erosion and alteration of tephra deposits, burial of tephra deposits by younger deposits and disappearance of the source volcano itself due to burial or erosion. Therefore, under-recording of events varies temporally and spatially, reflecting geological and historical backgrounds. For example, an analysis of the Japanese eruption events suggest that many large eruptions are missing in the Izu-Bonin arc because the volcanic arc consists of small volcanic islands where wide-spread tephra deposits are less likely preserved. Understandings of the under-recording in different geological settings improve the estimation of recurrence rate of volcanic eruptions. Furthermore, Koyama (1999) pointed out that the historical record of Japanese volcanic eruptions increases in two time periods

  19. Fast calculation method of computer-generated cylindrical hologram using wave-front recording surface.

    PubMed

    Zhao, Yu; Piao, Mei-lan; Li, Gang; Kim, Nam

    2015-07-01

    Fast calculation method for a computer-generated cylindrical hologram (CGCH) is proposed. The method consists of two steps: the first step is a calculation of a virtual wave-front recording surface (WRS), which is located between the 3D object and CGCH. In the second step, in order to obtain a CGCH, we execute the diffraction calculation based on the fast Fourier transform (FFT) from the WRS to the CGCH, which are in the same concentric arrangement. The computational complexity is dramatically reduced in comparison with direct integration method. The simulation results confirm that our proposed method is able to improve the computational speed of CGCH.

  20. Record-breaking events during the compressive failure of porous materials.

    PubMed

    Pál, Gergő; Raischel, Frank; Lennartz-Sassinek, Sabine; Kun, Ferenc; Main, Ian G

    2016-03-01

    An accurate understanding of the interplay between random and deterministic processes in generating extreme events is of critical importance in many fields, from forecasting extreme meteorological events to the catastrophic failure of materials and in the Earth. Here we investigate the statistics of record-breaking events in the time series of crackling noise generated by local rupture events during the compressive failure of porous materials. The events are generated by computer simulations of the uniaxial compression of cylindrical samples in a discrete element model of sedimentary rocks that closely resemble those of real experiments. The number of records grows initially as a decelerating power law of the number of events, followed by an acceleration immediately prior to failure. The distribution of the size and lifetime of records are power laws with relatively low exponents. We demonstrate the existence of a characteristic record rank k(*), which separates the two regimes of the time evolution. Up to this rank deceleration occurs due to the effect of random disorder. Record breaking then accelerates towards macroscopic failure, when physical interactions leading to spatial and temporal correlations dominate the location and timing of local ruptures. The size distribution of records of different ranks has a universal form independent of the record rank. Subsequences of events that occur between consecutive records are characterized by a power-law size distribution, with an exponent which decreases as failure is approached. High-rank records are preceded by smaller events of increasing size and waiting time between consecutive events and they are followed by a relaxation process. As a reference, surrogate time series are generated by reshuffling the event times. The record statistics of the uncorrelated surrogates agrees very well with the corresponding predictions of independent identically distributed random variables, which confirms that temporal and spatial

  1. Fast and accurate dating of nuclear events using La-140/Ba-140 isotopic activity ratio.

    PubMed

    Yamba, Kassoum; Sanogo, Oumar; Kalinowski, Martin B; Nikkinen, Mika; Koulidiati, Jean

    2016-06-01

    This study reports on a fast and accurate assessment of zero time of certain nuclear events using La-140/Ba-140 isotopic activity ratio. For a non-steady nuclear fission reaction, the dating is not possible. For the hypothesis of a nuclear explosion and for a release from a steady state nuclear fission reaction the zero-times will differ. This assessment is fast, because we propose some constants that can be used directly for the calculation of zero time and its upper and lower age limits. The assessment is accurate because of the calculation of zero time using a mathematical method, namely the weighted least-squares method, to evaluate an average value of the age of a nuclear event. This was done using two databases that exhibit differences between the values of some nuclear parameters. As an example, the calculation method is applied for the detection of radionuclides La-140 and Ba-140 in May 2010 at the radionuclides station JPP37 (Okinawa Island, Japan).

  2. Methods of and apparatus for recording images occurring just prior to a rapid, random event

    DOEpatents

    Kelley, Edward F.

    1994-01-01

    An apparatus and a method are disclosed for recording images of events in a medium wherein the images that are recorded are of conditions existing just prior to and during the occurrence of an event that triggers recording of these images. The apparatus and method use an optical delay path that employs a spherical focusing mirror facing a circular array of flat return mirrors around a central flat mirror. The image is reflected in a symmetric pattern which balances astigmatism which is created by the spherical mirror. Delays on the order of hundreds of nanoseconds are possible.

  3. Event Plane Resolution Simulations for The Fast Interaction Trigger Detector of ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Sulaimon, Isiaka; Harton, Austin; Garcia, Edmundo; Alice-Fit Collaboration

    2016-03-01

    CERN (European Center for Nuclear Research) is a global laboratory that studies proton and heavy ion collisions at the Large Hadron Collider (LHC). ALICE (A Large Ion Collider Experiment) is one of four large experiments of the LHC. ALICE is dedicated to the study of the transition of matter to Quark Gluon Plasma in heavy ion collisions. In the present ALICE detector there are two sub-detectors, (the T0 and V0), that provide minimum bias trigger, multiplicity trigger, beam-gas event rejection, collision time for other sub detectors, on line multiplicity and event plane determination. In order to adapt these functionalities to the collision rates expected for the LHC upgrade after 2020, it is planned to replace these systems by a single detector system, called the Fast Interaction Trigger (FIT). In this presentation we describe the performance parameters of the FIT upgrade; show the proposed characteristics of the T0-Plus and the simulations that support the conceptual design of this detector. In particular we describe the performance simulations of the event plane resolution. This material is based upon work supported by the National Science Foundation under Grants NSF-PHY-0968903 and NSF-PHY-1305280.

  4. Geological record of meltwater events at Qinghai Lake, China from the past 40 ka

    NASA Astrophysics Data System (ADS)

    Zhou, Weijian; Liu, Taibei; Wang, Hao; An, Zhisheng; Cheng, Peng; Zhu, Yizhi; Burr, G. S.

    2016-10-01

    We report here on a previously unpublished sediment core from Qinghai Lake, China, that preserves a continuous record of sedimentation for the past 40 ka. A striking feature of the record is a set of distinct meltwater events recorded at 35, 19 and 14 ka respectively. These events are manifest as distinct pulses of relatively old organic radiocarbon in the sediments. We interpret these as a signal of glacial melting in the Qinghai Lake watershed. The meltwater signals are closely correlated to temperature and precipitation records associated with deglaciation. The events at 19 ka and 14 ka correspond to well-established high latitude Melt Water Pulse (MWP) events during Marine Isotope Stage (MIS) 2, and the 35 ka event corresponds to a period of pervasive high lake levels in western China during late MIS 3. We interpret these anomalous dates as the result of relatively old carbon that was destabilized by the glaciers, and released into the lake as the glaciers melted. The data indicate that this process takes thousands of years. We expect that the approach employed here to identify these events is generally applicable to any lake system with a significant glacial meltwater component.

  5. Three thousand years of extreme rainfall events recorded in stalagmites from Spring Valley Caverns, Minnesota

    NASA Astrophysics Data System (ADS)

    Dasgupta, Sushmita; Saar, Martin O.; Edwards, R. Lawrence; Shen, Chuan-Chou; Cheng, Hai; Alexander, E. Calvin

    2010-11-01

    Annual layer analysis in two stalagmites collected from Spring Valley Caverns, southeastern Minnesota, reveals hydrological response of the cave to extreme rainfall events in the Midwest, USA. Cave-flooding events are identified within the two samples by the presence of detrital layers composed of clay sized particles. Comparison with instrumental records of precipitation demonstrates a strong correlation between these cave-flood events and extreme rainfall observed in the Upper Mississippi Valley. A simple model is developed to assess the nature of rainfall capable of flooding the cave. The model is first calibrated to the last 50-yr (1950-1998 A.D.) instrumental record of daily precipitation data for the town of Spring Valley and verified with the first 50 yr of record from 1900 to 1949 A.D. Frequency analysis shows that these extreme flood events have increased from the last half of the nineteenth century. Comparison with other paleohydrological records shows increased occurrence of extreme rain events during periods of higher moisture availability. Our study implies that increased moisture availability in the Midwestern region, due to rise in temperature from global warming could lead to an increase in the occurrence of extreme rainfall events.

  6. SEPServer Solar Energetic Particle event Catalogues at 1 AU based on STEREO recordings: selected solar cycle 24 SEP event analysis

    NASA Astrophysics Data System (ADS)

    Papaioannou, Athanasios; Malandraki, Olga E.; Dresing, Nina; Klein, Karl-Ludwig; Heber, Bernd; Vainio, Rami; Nindos, Alexander; Rodríguez-Gasén, Rosa; Klassen, Andreas; Gómez Herrero, Raúl; Vilmer, Nicole; Mewaldt, Richard A.

    2014-05-01

    STEREO (Solar TErrestrial RElations Observatory) recordings provide an unprecedented opportunity to identify the evolution of Solar Energetic Particles (SEPs) at different observing points in the heliosphere. In this work, two instruments onboard STEREO have been used in order to identify all SEP events observed within the deciding phase of solar cycle 23 and the rising phase of solar cycle 24 from 2007 to 2012, namely: the Low Energy Telescope (LET) and the Solar Electron Proton Telescope (SEPT). A scan over STEREO/LET protons within the energy range 6-10 MeV has been performed for each of the two STEREO spacecraft. Furthermore, parallel scanning of the STEREO/SEPT electrons in order to pinpoint the presence (or not) of an electron event has been performed in the energy range of 55-85 keV, for all of the aforementioned proton events, included in our lists. We provide the onset and peak times as well as the peak value of all events for both protons and electrons. Time-shifting analysis for near relativistic electrons leads to the inferred solar release time and to the relevant solar associations from radio spectrographs (Nançay Decametric Array; STEREO/WAVES) to GOES Soft X-rays and hard X-rays from RHESSI. The aforementioned information materializes the STEREO SEPServer catalogues that recently have been released to the scientific community. In order to demonstrate the exploitation of the STEREO catalogues, we then focus at the series of SEP events that were recorded onboard STEREO A & B as well as at L1 (ACE, SOHO) from March 4-14, 2012. We track the activity of active region (AR) 1429 during its passage from the East to the West which produced a number of intense solar flares and coronal mass ejections and we compare the magnetic connectivity of each spacecraft in association with the corresponding SEP signatures. During this period the longitudinal separation of the STEREO spacecraft was > 220 degrees, yet both of them recorded SEP events. These complex multi

  7. A New Characteristic Function for Fast Time-Reverse Seismic Event Location

    NASA Astrophysics Data System (ADS)

    Hendriyana, Andri; Bauer, Klaus; Weber, Michael; Jaya, Makky; Muksin, Muksin

    2015-04-01

    Microseismicity produced by natural activities is usually characterized by low signal-to-noise ratio and huge amount of data as recording is conducted for a long period of time. Locating microseismic events is preferably carried out using migration-based methods such as time-reverse modeling (TRM). The original TRM is based on backpropagating the wavefield from the receiver down to the source location. Alternatively, we are using a characteristic function (CF) derived from the measured wavefield as input for the TRM. The motivation for such a strategy is to avoid undesired contributions from secondary arrivals which may generate artifacts in the final images. In this presentation, we introduce a new CF as input for TRM method. To obtain this CF, initially we apply kurtosis-based automatic onset detection and convolution with a given wavelet. The convolution with low frequency wavelets allows us to conduct time-reverse modeling using coarser sampling hence it will reduce computing time. We apply the method to locate seismic events measured along an active part of the Sumatra Fault around the Tarutung pull-apart basin (North Sumatra, Indonesia). The results show that seismic events are well-determined since they are concentrated along the Sumatran fault. Internal details of the Tarutung basin structure could be derived. Our results are consistent with those obtained from inversion of manually picked travel time data.

  8. Motivation and intention to integrate physical activity into daily school life: the JAM World Record event.

    PubMed

    Vazou, Spyridoula; Vlachopoulos, Symeon P

    2014-11-01

    Research on the motivation of stakeholders to integrate physical activity into daily school life is limited. The purpose was to examine the motivation of stakeholders to participate in a world record physical activity event and whether motivation was associated with future intention to use activity breaks during the daily school life and future participation in a similar event. After the 2012 JAM (Just-a-Minute) World Record event, 686 adults (591 women; 76.1% participated for children <10 years) completed measures of motivational regulations and future intention to (a) use the activity breaks and (b) participate in the event. High intrinsic motivation and low extrinsic motivation and amotivation for participation in the next event were reported. Hierarchical regression analysis, controlling for age, gender, and occupation, showed that intrinsic forms of motivation positively predicted, whereas amotivation negatively predicted, future intention to participate in the event and use the activity breaks. Multivariate analyses of variance revealed that school-related participants were more intrinsically motivated and intended to use the activity breaks and repeat the event more than those who were not affiliated with a school. Nonschool participants reported higher extrinsic motivation and amotivation than school-related participants. PMID:25001232

  9. Motivation and intention to integrate physical activity into daily school life: the JAM World Record event.

    PubMed

    Vazou, Spyridoula; Vlachopoulos, Symeon P

    2014-11-01

    Research on the motivation of stakeholders to integrate physical activity into daily school life is limited. The purpose was to examine the motivation of stakeholders to participate in a world record physical activity event and whether motivation was associated with future intention to use activity breaks during the daily school life and future participation in a similar event. After the 2012 JAM (Just-a-Minute) World Record event, 686 adults (591 women; 76.1% participated for children <10 years) completed measures of motivational regulations and future intention to (a) use the activity breaks and (b) participate in the event. High intrinsic motivation and low extrinsic motivation and amotivation for participation in the next event were reported. Hierarchical regression analysis, controlling for age, gender, and occupation, showed that intrinsic forms of motivation positively predicted, whereas amotivation negatively predicted, future intention to participate in the event and use the activity breaks. Multivariate analyses of variance revealed that school-related participants were more intrinsically motivated and intended to use the activity breaks and repeat the event more than those who were not affiliated with a school. Nonschool participants reported higher extrinsic motivation and amotivation than school-related participants.

  10. An Analytical Approach for Estimating Fossil Record and Diversification Events in Sharks, Skates and Rays

    PubMed Central

    Guinot, Guillaume; Adnet, Sylvain; Cappetta, Henri

    2012-01-01

    Background Modern selachians and their supposed sister group (hybodont sharks) have a long and successful evolutionary history. Yet, although selachian remains are considered relatively common in the fossil record in comparison with other marine vertebrates, little is known about the quality of their fossil record. Similarly, only a few works based on specific time intervals have attempted to identify major events that marked the evolutionary history of this group. Methodology/Principal Findings Phylogenetic hypotheses concerning modern selachians’ interrelationships are numerous but differ significantly and no consensus has been found. The aim of the present study is to take advantage of the range of recent phylogenetic hypotheses in order to assess the fit of the selachian fossil record to phylogenies, according to two different branching methods. Compilation of these data allowed the inference of an estimated range of diversity through time and evolutionary events that marked this group over the past 300 Ma are identified. Results indicate that with the exception of high taxonomic ranks (orders), the selachian fossil record is by far imperfect, particularly for generic and post-Triassic data. Timing and amplitude of the various identified events that marked the selachian evolutionary history are discussed. Conclusion/Significance Some identified diversity events were mentioned in previous works using alternative methods (Early Jurassic, mid-Cretaceous, K/T boundary and late Paleogene diversity drops), thus reinforcing the efficiency of the methodology presented here in inferring evolutionary events. Other events (Permian/Triassic, Early and Late Cretaceous diversifications; Triassic/Jurassic extinction) are newly identified. Relationships between these events and paleoenvironmental characteristics and other groups’ evolutionary history are proposed. PMID:22957091

  11. A lacustrine record of early Holocene watershed events and vegetation history, Corvara in Badia, Dolomites (Italy)

    NASA Astrophysics Data System (ADS)

    Borgatti, Lisa; Ravazzi, Cesare; Donegana, Marta; Corsini, Alessandro; Marchetti, Mauro; Soldati, Mauro

    2007-02-01

    The early-middle Holocene lacustrine succession of Corvara in Badia (Italian Dolomites, 1521 m a.s.l.) records landslides and other watershed events before the onset of human pressure. The sensitivity of this archive to relate climate change, watershed processes and vegetation dynamics in the catchment has been explored through a stratigraphic study, including the analysis of sedimentological features, magnetic properties, palaeobotanical records and radiocarbon dating. A palaeolake existed between 10.1 k and 7 k cal. yr BP and was surrounded by a dense conifer forest. Long-term forest dynamics driven by ecological processes and by climatic conditions favourable to upward forest expansion is recorded throughout the pollen record. Within the fine clastic sedimentation, distinct layers enriched in organic debris of terrestrial origin have been attributed to instant events produced by mass movements. Their age fits the chronology of large landslide events already known in the catchment, enabling correlation of the field evidence of landslides with the lacustrine record. Landslide frequency is controlled by geological and structural factors, but it is significantly modulated by the centennial-millennial climatic phases that characterise the Holocene in the Alps. The taphonomical properties of pollen and macroremains provided valuable insight on the mechanism of watershed processes. Copyright

  12. Plant microfossil record of the terminal Cretaceous event in the western United States and Canada

    NASA Technical Reports Server (NTRS)

    Nichols, D. J.; Fleming, R. F.

    1988-01-01

    Plant microfossils, principally pollen grains and spores produced by land plants, provide an excellent record of the terminal Cretaceous event in nonmarine environments. The record indicates regional devastation of the latest Cretaceous vegetation with the extinction of many groups, followed by a recolonization of the earliest Tertiary land surface, and development of a permanently changed land flora. The regional variations in depositional environments, plant communities, and paleoclimates provide insight into the nature and effects of the event, which were short-lived but profound. The plant microfossil data support the hypothesis that an abruptly initiated, major ecological crisis occurred at the end of the Cretaceous. Disruption of the Late Cretaceous flora ultimately contributred to the rise of modern vegetation. The plant microfossils together with geochemical and mineralogical data are consistent with an extraterrestrial impact having been the cause of the terminal Cretaceous event.

  13. A case study of two sprite events recorded over western Europe

    NASA Astrophysics Data System (ADS)

    Odzimek, Anna; Bór, József; Mielniczek, Magdalena; Pajek, Monika; Struzik, Piotr; Novak, Petr

    2013-04-01

    A low-light television camera and computer software for observations of Transient Luminous Events was installed in Gliwice (18.65 E, 50.28 N), southern Poland, during the summer of 2011. The optical observations have been supported by meterological products used for monitoring thunderstorm activity over Europe, including EUMETSAT Meteosat-9 difference images called `overshooting tops'. On 11 September two sprites have been recorded over a thunderstorm approaching the Czech Republic from the west. The two events were also recorded from Sopron (16.58 E, 46.68 N), west Hungary. We use these simultaneous observations to calculate the locations of the sprites, particularly in relation to the lightning strokes that preceded them. We also investigate possible scenarios that may have led to the two events.

  14. On modelling the Fast Radio Burst population and event rate predictions

    NASA Astrophysics Data System (ADS)

    Bera, Apurba; Bhattacharyya, Siddhartha; Bharadwaj, Somnath; Bhat, N. D. Ramesh; Chengalur, Jayaram N.

    2016-04-01

    Assuming that Fast Radio Bursts (FRBs) are of extragalactic origin, we have developed a formalism to predict the FRB detection rate and the redshift distribution of the detected events for a telescope with given parameters. We have adopted FRB 110220, for which the emitted pulse energy is estimated to be E0 = 5.4 × 1033 J, as the reference event. The formalism requires us to assume models for (a) pulse broadening due to scattering in the ionized intergalactic medium - we consider two different models for this, (b) the frequency spectrum of the emitted pulse - we consider a power-law model Eν ∝ ν-α with -5 ≤ α ≤ 5, and (c) the comoving number density of the FRB occurrence rate n(E, wi, z) - we ignore the z dependence and assume a fixed intrinsic pulse width wi = 1 ms for all the FRBs. The distribution of the emitted pulse energy E is modelled through (a) a delta function where all the FRBs have the same energy E = E0, and (b) a Schechter luminosity function where the energies have a spread around E0. The models are all normalized using the four FRBs detected by Thornton et al. Our model predictions for the Parkes telescope are all consistent with the inferred redshift distribution of the 14 FRBs detected there to date. We also find that scattering places an upper limit on the redshift of the FRBs detectable by a given telescope; for the Parkes telescope, this is z ˜ 2. Considering the upcoming Ooty Wide Field Array, we predict an FRB detection rate of ˜0.01 to ˜103 d-1.

  15. PImMS, a fast event-triggered monolithic pixel detector with storage of multiple timestamps

    NASA Astrophysics Data System (ADS)

    John, J. J.; Brouard, M.; Clark, A.; Crooks, J.; Halford, E.; Hill, L.; Lee, J. W. L.; Nomerotski, A.; Pisarczyk, R.; Sedgwick, I.; Slater, C. S.; Turchetta, R.; Vallance, C.; Wilman, E.; Winter, B.; Yuen, W. H.

    2012-08-01

    PImMS, or Pixel Imaging Mass Spectrometry, is a novel high-speed monolithic CMOS imaging sensor tailored to mass spectrometry requirements, also suitable for other dark-field applications. In its application to time-of-flight mass spectrometry, the sensor permits ion arrival time distributions to be combined with 2D imaging, providing additional information about the initial position or velocity of ions under study. PImMS1, the first generation sensor in this family, comprises an array of 72 by 72 pixels on a 70 μm by 70 μm pitch. Pixels independently record digital timestamps when events occur over an adjustable threshold. Each pixel contains 4 memories to record timestamps at a resolution of 25 ns. The sensor was designed and manufactured in the INMAPS 0.18 μm process. This allows the inclusion of significant amounts of circuitry (over 600 transistors) within each pixel while maintaining good detection efficiency. We present an overview of the pixel and sensor architecture, explain its functioning and present test results, ranging from characterisation of the analogue front end of the pixel, to verification of its digital functions, to some first images captured on mass spectrometers. We conclude with an overview of the upcoming second generation of PImMS sensors.

  16. Continuous methane record of abrupt climate change 10-68 ka: sighting Heinrich events in the ice core record

    NASA Astrophysics Data System (ADS)

    Rhodes, Rachael; Brook, Edward; Chiang, John; Blunier, Thomas; Cheng, Hai; Edwards, R. Lawrence; Maselli, Olivia; McConnell, Joseph; Romanini, Daniele; Severinghaus, Jeffrey; Sowers, Todd; Stowasser, Christopher

    2014-05-01

    The Last Glacial period was punctuated by millennial scale abrupt climate changes - Dansgaard-Oeschger (D-O) cycles and Heinrich events. Controls on the magnitude and frequency of these climate perturbations, and how they may be inter-related, remain unclear. Specific problems include the difficulty of dating Heinrich sediment layers and local bias of key paleoclimate archives. We present a highly detailed and precise record of ice core methane (CH4), a globally integrated signal, which resolves climatic features in unprecedented resolution. Abrupt CH4 increases are resolved in Heinrich Stadials (HS) 1, 2, 4 and 5 where, in contrast to all D-O cycles, there are no concurrent abrupt changes in Greenland temperature. Using modern-day tropical rainfall variability as an analog, we propose that strong cooling in the North Atlantic severely restricted the northerly range of the Intertropical Convergence Zone (ITCZ), leading to an enhanced wet season over Southern Hemisphere tropical land areas, and consequently driving production of excess CH4 in tropical wetlands. Our findings place four Heinrich events firmly within ice core chronologies and suggest maximum durations of 778 to 1606 yr. CH4 anomalies are only associated with Heinrich events of Hudson Strait provenance, indicating that the tropical impacts of Heinrich events were not uniform.

  17. A scheme for recording a fast process at nanosecond scale by using digital holographic interferometry with continuous wave laser

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Zhao, Jianlin; Di, Jianglei; Jiang, Biqiang

    2015-04-01

    A scheme for recording fast process at nanosecond scale by using digital holographic interferometry with continuous wave (CW) laser is described and demonstrated experimentally, which employs delayed-time fibers and angular multiplexing technique and can realize the variable temporal resolution at nanosecond scale and different measured depths of object field at certain temporal resolution. The actual delay-time is controlled by two delayed-time fibers with different lengths. The object field information in two different states can be simultaneously recorded in a composite hologram. This scheme is also suitable for recording fast process at picosecond scale, by using an electro-optic modulator.

  18. Geochemical Records of Bleaching Events and the Associated Stressors From the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Roark, E. B.; McCulloch, M.; Ingram, B. L.; Marshall, J. F.

    2003-12-01

    The health of coral reefs world-wide is increasingly threatened by a wide array of stressors. On the Great Barrier Reef (GBR) these stressors include increased sediment flux associated with land use changes, increased sea surface temperatures (SST) and salinity changes due to large floods, the latter two of which are factors in an increased number of bleaching events. The ability to document long-term change in these stressors along with changes in the number of bleaching events would help discern what are natural and anthropogenic changes in this ecosystem. Here we present results of an initial calibration effort aimed at identifying bleaching events and the associated stressors using stable isotopic and trace element analysis in coral cores. Three ˜15-year time series of geochemical measurements (δ 13C, δ 18O, and Sr/Ca) on Porites coral cores obtained from Pandora Reef and the Keppel Islands on the GBR have been developed at near weekly resolution. Since the δ 13C of the coral skeletal carbonate is known to be affected by both environmental factors (e.g. insolation and temperature) and physiological factors (e.g. photosynthesis, calcification, and the statues of the symbiotic relationship between corals and zooxanthellae) it is the most promising proxy for reconstructing past bleaching events. The first record (PAN-98) comes from a coral head that had undergone bleaching and died shortly after the large-scale bleaching events on Pandora Reef in 1998. A second core (PAN-02) was collected from a living coral within 10m of PAN-98 in 2002. Sr/Ca ratios in both cores tracked even the smallest details of an in situ SST record. The increase in SST that occurred three to four weeks prior to bleaching was faithfully recorded by a similar decrease in the Sr/Ca ratio in PAN-98, indicating that calcification continued despite the high SST of 30-31° C. The δ 13C values decreased by about 5‰ , one week after the SST increase, and remained at this value for about 4

  19. Multi-proxy fingerprint of Heinrich event 4 in Greenland ice core records

    NASA Astrophysics Data System (ADS)

    Guillevic, M.; Bazin, L.; Landais, A.; Stowasser, C.; Masson-Delmotte, V.; Blunier, T.; Eynaud, F.; Falourd, S.; Michel, E.; Minster, B.; Popp, T.; Prié, F.; Vinther, B. M.

    2014-03-01

    Glacial climate was characterised by two types of abrupt events. Greenland ice cores record Dansgaard-Oeschger events, marked by abrupt warming in-between cold, stadial phases. Six of these stadials coincide with major Heinrich events (HE), identified from ice-rafted debris (IRD) and large excursions in carbon and oxygen stable isotopic ratios in North Atlantic deep sea sediments, documenting major ice sheet collapse events. This finding has led to the paradigm that glacial cold events are induced by the response of the Atlantic Meridional Overturning Circulation to such massive freshwater inputs, supported by sensitivity studies conducted with climate models of various complexities. This mechanism could however never be confirmed or infirmed because the exact timing of Heinrich events and associated low latitude hydrological cycle changes with respect to Greenland stadials has so far remained elusive. Here, we provide the first multi-proxy fingerprint of H4 within Stadial 9 in Greenland ice cores through ice and air proxies of low latitude climate and water cycle changes. Our new dataset demonstrates that Stadial 9 consists of three phases, characterised first by Greenland cooling during 550 ± 60 years (as shown by markers of Greenland temperature δ18O and δ15N), followed by the fingerprint of Heinrich Event 4 as identified from several proxy records (abrupt decrease in 17O excess and Greenland methane sulfonic acid (MSA), increase in CO2 and methane mixing ratio, heavier δ D-CH4 and δ18Oatm), lasting 740 ± 60 years, itself ending approximately 390 ± 50 years prior to abrupt Greenland warming. Preliminary investigations on GS-13 encompassing H5, based on the ice core proxies δ18O, MSA, δ18Oatm, CH4 and CO2 data also reveal a 3 phase structure, as well as the same sequence of events. The decoupling between stable cold Greenland temperature and low latitude HE imprints provides new targets for benchmarking climate model simulations and testing mechanisms

  20. Spectra of solar proton ground level events using neutron monitor and neutron moderated detector recordings

    NASA Technical Reports Server (NTRS)

    Stoker, P. H.

    1985-01-01

    Recordings on relativistic solar flare protons observed at Sanae, Antarctic, show that the percentage increase in counting rates of the neutron moderated detector (4NMD) is larger than the percentage increase in counting rates of the 3NM64 neutron monitor. These relative increases are described by solar proton differential spectra j sub s(P) = AP(beta). The power beta is determined for each event and the hardnesses of the temporal variations of beta, found for the ground level events (GLE) of 7 May, 1978 and 22 November, 1977.

  1. Contrasting sulfur isotope records during the Late Devonian punctata and Upper Kellwasser events

    NASA Astrophysics Data System (ADS)

    Sim, M.; Ono, S.; Hurtgen, M. T.

    2013-12-01

    The Late Devonian was a period of intense biological and environmental changes, including terrestrial afforestation, a series of asteroid impacts, and active orogeny due to the accretion of continental blocks. High amplitude positive carbon isotope excursions, the punctata and Kellwasser events, reflect major perturbations in the global carbon cycle during this period, which have been attributed to increased continental weathering and subsequent ocean eutrophication. Despite the comparable carbon isotope anomalies, however, a global biological crisis has been reported only for the Kellwasser events, while very low extinction intensity characterizes the punctata Event. We will present sulfur isotope records of carbonate associated sulfate (CAS) and pyrite from Frasnian-Famennian sections in the Great Basin, USA, and evaluate the role of sulfur during the punctata and Upper Kellwasser events. A positive sulfur isotope shift in both CAS and pyrite accompanies the onset of the punctata Event, but with a larger extent in the latter. As a result, the sulfur isotope offset between CAS and pyrite (Δ34SCAS-py) plummeted to less than 10‰. In the middle of the punctata Event, a sharp negative δ34SCAS excursion occurred just after the Alamo Impact, leading to the negative Δ34SCAS-py values. Unlike the rapid oscillations of δ34Spy and δ34SCAS during the punctata Event, the Upper Kellwasser was a period of stability, except for a brief drop of δ34SCAS before the event. Paired sulfur isotope data, aided by a simple box model, suggests that geochemical cycle of sulfur might be responsible for the contrasting biological responses to these two events. Superheavy pyrite and high stratigraphic variability of δ34Spy and δ34SCAS demonstrate a relatively small oceanic sulfate pool during the punctata Event, and the Alamo Impact likely triggered to the rapid oxidation of microbially-produced sulfide. The expansion of sulfidic bottom water thus may have been impeded, thereby

  2. Ultra-high throughput real-time instruments for capturing fast signals and rare events

    NASA Astrophysics Data System (ADS)

    Buckley, Brandon Walter

    processing. The act of time-stretching effectively boosts the performance of the back-end electronics and digital signal processors. The slowed down signals reach the back-end electronics with reduced bandwidth, and are therefore less affected by high-frequency roll-off and distortion. Time-stretching also increases the effective sampling rate of analog-to-digital converters and reduces aperture jitter, thereby improving resolution. Finally, the instantaneous throughputs of digital signal processors are enhanced by the stretch factor to otherwise unattainable speeds. Leveraging these unique capabilities, TiSER becomes the ideal tool for capturing high-speed signals and characterizing rare phenomena. For this thesis, I have developed techniques to improve the spectral efficiency, bandwidth, and resolution of TiSER using polarization multiplexing, all-optical modulation, and coherent dispersive Fourier transformation. To reduce the latency and improve the data handling capacity, I have also designed and implemented a real-time digital signal processing electronic backend, achieving 1.5 tera-bit per second instantaneous processing throughput. Finally, I will present results from experiments highlighting TiSER's impact in real-world applications. Confocal fluorescence microscopy is the most widely used method for unveiling the molecular composition of biological specimens. However, the weak optical emission of fluorescent probes and the tradeoff between imaging speed and sensitivity is problematic for acquiring blur-free images of fast phenomena and cells flowing at high speed. Here I introduce a new fluorescence imaging modality, which leverages techniques from wireless communication to reach record pixel and frame rates. Termed Fluorescence Imaging using Radio-frequency tagged Emission (FIRE), this new imaging modality is capable of resolving never before seen dynamics in living cells - such as action potentials in neurons and metabolic waves in astrocytes - as well as

  3. Nonlinear Cross-Bridge Elasticity and Post-Power-Stroke Events in Fast Skeletal Muscle Actomyosin

    PubMed Central

    Persson, Malin; Bengtsson, Elina; ten Siethoff, Lasse; Månsson, Alf

    2013-01-01

    Generation of force and movement by actomyosin cross-bridges is the molecular basis of muscle contraction, but generally accepted ideas about cross-bridge properties have recently been questioned. Of the utmost significance, evidence for nonlinear cross-bridge elasticity has been presented. We here investigate how this and other newly discovered or postulated phenomena would modify cross-bridge operation, with focus on post-power-stroke events. First, as an experimental basis, we present evidence for a hyperbolic [MgATP]-velocity relationship of heavy-meromyosin-propelled actin filaments in the in vitro motility assay using fast rabbit skeletal muscle myosin (28–29°C). As the hyperbolic [MgATP]-velocity relationship was not consistent with interhead cooperativity, we developed a cross-bridge model with independent myosin heads and strain-dependent interstate transition rates. The model, implemented with inclusion of MgATP-independent detachment from the rigor state, as suggested by previous single-molecule mechanics experiments, accounts well for the [MgATP]-velocity relationship if nonlinear cross-bridge elasticity is assumed, but not if linear cross-bridge elasticity is assumed. In addition, a better fit is obtained with load-independent than with load-dependent MgATP-induced detachment rate. We discuss our results in relation to previous data showing a nonhyperbolic [MgATP]-velocity relationship when actin filaments are propelled by myosin subfragment 1 or full-length myosin. We also consider the implications of our results for characterization of the cross-bridge elasticity in the filament lattice of muscle. PMID:24138863

  4. A Luminous, Fast Rising UV-transient Discovered by ROTSE: A Tidal Disruption Event?

    NASA Astrophysics Data System (ADS)

    Vinkó, J.; Yuan, F.; Quimby, R. M.; Wheeler, J. C.; Ramirez-Ruiz, E.; Guillochon, J.; Chatzopoulos, E.; Marion, G. H.; Akerlof, C.

    2015-01-01

    We present follow-up observations of an optical transient (OT) discovered by ROTSE on 2009 January 21. Photometric monitoring was carried out with ROTSE-IIIb in the optical and Swift in the UV up to +70 days after discovery. The light curve showed a fast rise time of ~10 days followed by a steep decline over the next 60 days, which was much faster than that implied by 56Ni—56Co radioactive decay. The Sloan Digital Sky Survey Data Release 10 database contains a faint, red object at the position of the OT, which appears slightly extended. This and other lines of evidence suggest that the OT is of extragalactic origin, and this faint object is likely the host galaxy. A sequence of optical spectra obtained with the 9.2 m Hobby-Eberly Telescope between +8 and +45 days after discovery revealed a hot, blue continuum with no visible spectral features. A few weak features that appeared after +30 days probably originated from the underlying host. Fitting synthetic templates to the observed spectrum of the host galaxy revealed a redshift of z = 0.19. At this redshift, the peak magnitude of the OT is close to -22.5, similar to the brightest super-luminous supernovae; however, the lack of identifiable spectral features makes the massive stellar death hypothesis less likely. A more plausible explanation appears to be the tidal disruption of a Sun-like star by the central supermassive black hole. We argue that this transient likely belongs to a class of super-Eddington tidal disruption events.

  5. A LUMINOUS, FAST RISING UV-TRANSIENT DISCOVERED BY ROTSE: A TIDAL DISRUPTION EVENT?

    SciTech Connect

    Vinkó, J.; Wheeler, J. C.; Chatzopoulos, E.; Marion, G. H.; Yuan, F.; Akerlof, C.; Quimby, R. M.; Ramirez-Ruiz, E.; Guillochon, J.

    2015-01-01

    We present follow-up observations of an optical transient (OT) discovered by ROTSE on 2009 January 21. Photometric monitoring was carried out with ROTSE-IIIb in the optical and Swift in the UV up to +70 days after discovery. The light curve showed a fast rise time of ∼10 days followed by a steep decline over the next 60 days, which was much faster than that implied by {sup 56}Ni—{sup 56}Co radioactive decay. The Sloan Digital Sky Survey Data Release 10 database contains a faint, red object at the position of the OT, which appears slightly extended. This and other lines of evidence suggest that the OT is of extragalactic origin, and this faint object is likely the host galaxy. A sequence of optical spectra obtained with the 9.2 m Hobby-Eberly Telescope between +8 and +45 days after discovery revealed a hot, blue continuum with no visible spectral features. A few weak features that appeared after +30 days probably originated from the underlying host. Fitting synthetic templates to the observed spectrum of the host galaxy revealed a redshift of z = 0.19. At this redshift, the peak magnitude of the OT is close to –22.5, similar to the brightest super-luminous supernovae; however, the lack of identifiable spectral features makes the massive stellar death hypothesis less likely. A more plausible explanation appears to be the tidal disruption of a Sun-like star by the central supermassive black hole. We argue that this transient likely belongs to a class of super-Eddington tidal disruption events.

  6. Fast three-dimensional random access multi-photon microscopy for functional recording of neuronal activity

    NASA Astrophysics Data System (ADS)

    Reddy, Duemani; Saggau, Peter

    2007-07-01

    The dendritic processes of neurons have been shown to possess active and dynamic properties that give them the ability to modulate synaptic integration and shape individual synaptic responses. Effectively studying these properties at multiple locations on a live neuron in highly light scattering brain tissue requires an imaging/recording mechanism with high spatio-temporal resolution as well as optical sectioning and random access site selection capabilities. Our lab has made significant steps in developing such a system by combining the spatial resolution and optical sectioning ability of advanced imaging techniques such as confocal and multi-photon microscopy with the temporal resolution and random access capability provided by acousto-optic laser scanning. However, all systems that have been developed to date restrict fast imaging to two-dimensional (2D) scan patterns. This severely limits the extent to which many neurons can be studied since they represent complex three-dimensional (3D) structures. We have previously demonstrated a scheme for fast 3D scanning which utilizes a unique arrangement of acoustooptic deflectors and does not require axial movements of the objective lens. We have also shown how, when used with the ultra-fast laser pulses needed in multi-photon microscopy, this scheme inherently compensates for the spatial dispersion which would otherwise significantly reduce the resolution of acousto-optic based multi-photon microscopy. We have now coupled this scanning scheme to a modified commercial research microscope and use the combined system to effectively image user-defined sites of interest on fluorescent 3D structures with positioning times that are in the low microsecond (μs) range. The resulting random-access scanning mechanism allows for functional imaging of complex 3D structures such as neuronal dendrites at several thousand volumes per second.

  7. Solar Energetic Particle Events recorded aboard SOHO on December 24, 1996 and on May 6, 1998

    NASA Astrophysics Data System (ADS)

    McKenna-Lawlor, Susan M. P.; Kecskeméty; K.; Bothmer, V.; Rodriguez-Pacheco, J.; Facskó, G.; St. Cyr, C.

    The LION experiment on SOHO (which records protons from 44 keV-6 MeV and electrons from 44 keV-300 keV), and the energetically complementary EPHIN experiment (which measures protons + helium ions to >53 MeV/n and electrons to >5 MeV), each detected many energetic particle events (SEPs) in the early rising phase of Solar Cycle 23 (from ~ July 1996) - a period commonly associated with Coronal Mass Ejections (CMEs). The present paper contains an account of two representative rapid intensity increases recorded simultaneously by LION and EPHIN, each of which was accompanied by a CME and by impulsive type flaring. The SEPs have characteristics typical of both Gradual and Impulsive events and may be described as `Mixed'.

  8. New records with examples of potential host colonization events for hypopi (Acari: Hypoderatidae) from birds

    USGS Publications Warehouse

    Pence, Danny B.; Spalding, M.G.; Bergan, J.F.; Cole, R.A.

    1997-01-01

    New host, geographic records, or both are established for 14 species of hypoderatid deutonymphs from 14 species of birds in North America. Ten of these records are regarded as examples of a potential host colonization event where these hypopi have become established in hosts other than those with which they are normally associated. Herein, potential host colonization events by hypoderatid deutonymphs are regarded as more of an ecologically determined than physiologically specific phenomenon, often specifically related to sharing of nesting sites in the same rookeries by different host taxa. Neottialges ibisicola Young & Pence is placed as a junior synonym of Neottialges plegadicola Fain. The taxonomic status of Hypodectes propus from columbid versus ardeid hosts needs further study.

  9. Abrupt Climate Events Recorded in Chinese and Central Asian Loess Sequences

    NASA Astrophysics Data System (ADS)

    Machalett, B.; Oches, E. A.; Haam, E. K.; Lai, Z.; Endlicher, W.

    2013-12-01

    Past climate dynamics associated with the Eurasian continent have been extensively studied. However, the impact of intra-hemispheric-scale climate variability on the entire Eurasian landmass, as well as the self-generated effects of the continent on the global climate system, is still a matter of investigation . While western Atlantic polar and tropical air masses penetrate into the continent and are transformed as they cross Eurasia, the interior regions of Eurasia strongly influence Earth's climate system. Significant cooling and heating of Central and High Asia drive interactions between atmospheric and oceanic processes and regulate teleconnection patterns across the Northern Hemisphere. This paper utilizes high resolution particle size data from the Central Asian loess sequence at Remisowka, Kazakhstan, and the long studied, monsoon-influenced Chinese loess sequence at Xifeng, to reconstruct past atmospheric circulation and aeolian dust dynamics within interior Eurasia since the last interglacial period. The observed dynamics in aeolian dust transport closely mirror d18O and fine dust variations measured in Greenland ice cores, suggesting a correlation with short-term climate oscillations (DO events) recorded therein. An Asian origin of fine aeolian dust preserved in Greenland ice cores has been discussed previously, and recent papers reveal a close link between Asian aeolian dust dynamics and DO events recorded in Greenland ice cores. In this context, data presented here represent the first Central and East Asian aeolian dust records in which DO events are recorded, providing a means to test hypothesized links between short-term climate variability recorded in Greenland and associated climate dynamics at Asian dust source areas. Ultimately, the data extend existing hypotheses, suggesting that the Central and High Asian mountains are a crucial element within the sensitive glacier-desert-dust response system in interior Eurasia and may be considered a pacemaker

  10. Abrupt Climate Events Recorded in Chinese and Central Asian Loess Sequences

    NASA Astrophysics Data System (ADS)

    Machalett, Bjoern; Oches, Eric A.; Haam, Eddie; Lai, Zhongping; Endlicher, Wilfried

    2013-04-01

    Past climate dynamics associated with the Eurasian continent have been extensively studied. However, the impact of intra-hemispheric-scale climate variability on the entire Eurasian landmass, as well as the self-generated effects of the continent on the global climate system, is still a matter of investigation . While western Atlantic polar and tropical air masses penetrate into the continent and are transformed as they cross Eurasia, the interior regions of Eurasia strongly influence Earth's climate system. Significant cooling and heating of Central and High Asia drive interactions between atmospheric and oceanic processes and regulate teleconnection patterns across the Northern Hemisphere. This paper utilizes high resolution particle size data from the Central Asian loess sequence at Remisowka, Kazakhstan, and the long studied, monsoon-influenced Chinese loess sequence at Xifeng, to reconstruct past atmospheric circulation and aeolian dust dynamics within interior Eurasia since the last interglacial period. The observed dynamics in aeolian dust transport closely mirror d18O and fine dust variations measured in Greenland ice cores, suggesting a correlation with short-term climate oscillations (DO events) recorded therein. An Asian origin of fine aeolian dust preserved in Greenland ice cores has been discussed previously, and recent papers reveal a close link between Asian aeolian dust dynamics and DO events recorded in Greenland ice cores. In this context, data presented here represent the first Central and East Asian aeolian dust records in which DO events are recorded, providing a means to test hypothesized links between short-term climate variability recorded in Greenland and associated climate dynamics at Asian dust source areas. Ultimately, the data extend existing hypotheses, suggesting that the Central and High Asian mountains are a crucial element within the sensitive glacier-desert-dust response system in interior Eurasia and may be considered a pacemaker

  11. Lake isotope records of the 8200-year cooling event in western Ireland: Comparison with model simulations

    NASA Astrophysics Data System (ADS)

    Holmes, Jonathan A.; Tindall, Julia; Roberts, Neil; Marshall, William; Marshall, Jim D.; Bingham, Ann; Feeser, Ingo; O'Connell, Michael; Atkinson, Tim; Jourdan, Anne-Lise; March, Anna; Fisher, Elizabeth H.

    2016-01-01

    The early Holocene cooling, which occurred around 8200 calendar years before present, was a prominent abrupt event around the north Atlantic region. Here, we investigate the timing, duration, magnitude and regional coherence of the event as expressed in carbonate oxygen-isotope records from three lakes on northwest Europe's Atlantic margin in western Ireland, namely Loch Avolla, Loch Gealáin and Lough Corrib. An abrupt negative oxygen-isotope excursion lasted about 200 years. Comparison of records from three sites suggests that the excursion was primarily the result of a reduction of the oxygen-isotope values of precipitation, which was likely caused by lowered air temperatures, possibly coupled with a change in atmospheric circulation. Comparison of records from two of the lakes (Loch Avolla and Loch Gealáin), which have differing bathymetries, further suggests a reduction in evaporative loss of lake water during the cooling episode. Comparison of climate model experiments with lake-sediment isotope data indicates that effective moisture may have increased along this part of the northeast Atlantic seaboard during the 8200-year climatic event, as lower evaporation compensated for reduced precipitation.

  12. Ramadan fasting is not usually associated with the risk of cardiovascular events: A systematic review and meta-analysis.

    PubMed

    Turin, Tanvir C; Ahmed, Salim; Shommu, Nusrat S; Afzal, Arfan R; Al Mamun, Mohammad; Qasqas, Mahdi; Rumana, Nahid; Vaska, Marcus; Berka, Noureddine

    2016-01-01

    Over one billion Muslims worldwide fast during the month of Ramadan. Ramadan fasting brings about some changes in the daily lives of practicing Muslims, especially in their diet and sleep patterns, which are associated with the risk of cardiovascular diseases. Over the years, many original studies have made the effort to identify the possible impact of the Ramadan fast on cardiovascular diseases. This systematic review and meta-analysis is an attempt to present the summary of key findings from those articles and an appraisal of selected literature. A systematic search using keywords of ";Ramadan fasting" and ";cardiovascular diseases" was conducted in primary research article and gray-literature repositories, in combination with hand searching and snow balling. Fifteen studies were finally selected for data extraction on the outcomes of stroke, myocardial infarction, and congestive heart failure. The analysis revealed that the incidence of cardiovascular events during the Ramadan fast was similar to the nonfasting period. Ramadan fast is not associated with any change in incidence of acute cardiovascular disease. PMID:27186152

  13. Validation of Canadian mothers’ recall of events in labour and delivery with electronic health records

    PubMed Central

    2013-01-01

    Background Maternal report of events that occur during labour and delivery are used extensively in epidemiological research; however, the validity of these data are rarely confirmed. This study aimed to validate maternal self-report of events that occurred in labour and delivery with data found in electronic health records in a Canadian setting. Methods Data from the All Our Babies study, a prospective community-based cohort of women’s experiences during pregnancy, were linked to electronic health records to assess the validity of maternal recall at four months post-partum of events that occurred during labour and delivery. Sensitivity, specificity and kappa scores were calculated. Results were stratified by maternal age, gravidity and educational attainment. Results Maternal recall at four months post-partum was excellent for infant characteristics (gender, birth weight, gestational age, multiple births) and variables related to labour and delivery (mode of delivery, epidural, labour induction) (sensitivity and specificity >85%). Women who had completed a university degree had significantly better recall of labour induction and use of an epidural. Conclusion Maternal recall of infant characteristics and events that occurred during labour and delivery is excellent at four months post-partum and is a valid source of information for research purposes. PMID:23445768

  14. Extreme Weather Events and ENSO Recorded in Speleothems: Potential for Detailed Paleoclimate and Paleoecological Reconstructions

    NASA Astrophysics Data System (ADS)

    Frappier, A.; Sahagian, D.

    2001-12-01

    Speleothems are carbonate mineral deposits formed in caves by precipitation from rainwater that has percolated through soils and limestone bedrock. They are particularly useful for paleoclimate studies because they are easily collected and preserve detailed evidence of a variety of environmental changes. Analysis and interpretation of long-term speleothem records at interannual to century-scale has been an established technique, but recent work has demonstrated a variety of new proxy data available with more detailed sampling. New microsampling techniques (20-40 micron samples) now make it possible to analyze the stable isotopic composition of tropical stalagmites (~1mm/yr growth rates) at monthly to weekly temporal resolution. The modern record presented here demonstrates the ability of speleothems to act as in situ "weather stations", simultaneously recording changes in a variety of environmental factors through time. Recent speleothem calcite deposits from Belize yielded remarkable climate- and weather- recording ability. The stalagmite d13C record correlates strongly with the Southern Oscillation Index, a primary measure of El Nino and La Nina events. Annual growth band thickness is inversely correlated to annual precipitation. Preliminary analysis suggests that transient extreme events, such as tropical cyclones, also leave a recognizable imprint on the d18O record. Trace element and C-14 analysis can be used to distinguish between the contributions of biospheric and soil isotopic partitioning variability and abiotic factors derived from bedrock dissolution. To gain a more full understanding of the factors controlling complex depositional systems such as speleothems, modern calibration is crucial. Combining stable isotope and trace element analysis of speleothem calcite at high resolution enables a more complete characterization of variability in the karst biogeochemical system. Speleological archives have great potential to yield important inter-annual to sub

  15. A fast, robust algorithm for power line interference cancellation in neural recording

    NASA Astrophysics Data System (ADS)

    Keshtkaran, Mohammad Reza; Yang, Zhi

    2014-04-01

    Objective. Power line interference may severely corrupt neural recordings at 50/60 Hz and harmonic frequencies. The interference is usually non-stationary and can vary in frequency, amplitude and phase. To retrieve the gamma-band oscillations at the contaminated frequencies, it is desired to remove the interference without compromising the actual neural signals at the interference frequency bands. In this paper, we present a robust and computationally efficient algorithm for removing power line interference from neural recordings. Approach. The algorithm includes four steps. First, an adaptive notch filter is used to estimate the fundamental frequency of the interference. Subsequently, based on the estimated frequency, harmonics are generated by using discrete-time oscillators, and then the amplitude and phase of each harmonic are estimated by using a modified recursive least squares algorithm. Finally, the estimated interference is subtracted from the recorded data. Main results. The algorithm does not require any reference signal, and can track the frequency, phase and amplitude of each harmonic. When benchmarked with other popular approaches, our algorithm performs better in terms of noise immunity, convergence speed and output signal-to-noise ratio (SNR). While minimally affecting the signal bands of interest, the algorithm consistently yields fast convergence (<100 ms) and substantial interference rejection (output SNR >30 dB) in different conditions of interference strengths (input SNR from -30 to 30 dB), power line frequencies (45-65 Hz) and phase and amplitude drifts. In addition, the algorithm features a straightforward parameter adjustment since the parameters are independent of the input SNR, input signal power and the sampling rate. A hardware prototype was fabricated in a 65 nm CMOS process and tested. Software implementation of the algorithm has been made available for open access at https://github.com/mrezak/removePLI. Significance. The proposed

  16. The Boltysh crater record of rapid vegetation change during the Dan-C2 hyperthermal event.

    NASA Astrophysics Data System (ADS)

    Jolley, D. W.; Daly, R.; Gilmour, I.; Gilmour, M.; Kelley, S. P.

    2012-04-01

    Analysis of a cored borehole drilled through the sedimentary fill of the 24km wide Boltysh meteorite crater, Ukraine has yielded a unique, high resolution record spanning <1my of Early Paleocene terrestrial environmental change. While the oldest crater fill sediments preserve a record of the K/Pg boundary, overlying sediments preserve a record through the earliest Danian Dan-C2 hyperthermal event. This event is preserved in ~220m of lacustrine organic mudrocks and shows close similarities to the carbon isotope records of the Toarcian and PETM CIE's. At Boltysh, the rapid sedimentation rate and lack of bioturbation in the crater fill lacustrine deposits preserve uniquely high resolution pollen, spore and algae records. These records reflect environmental change from the K/Pg1 to the post Dan-C2 Danian. Leading into the CIE, warm temperate gymnosperm - angiosperm - fern communities are replaced by precipitation limited (winterwet) plant communities within the negative CIE. Winterwet plant communities dominate the negative CIE, but are replaced within the isotope recovery stage by warm temperate floras. These in turn give way to cooler temperate floras in the post positive CIE section of the uppermost crater fill. The distribution of temperate taxa about the negative CIE represents the broadest scale of oscillatory variation in the palynofloras. Shorter frequency oscillations are evident from diversity and botanical group distributions reflecting changes in moisture availability over several thousand years. Detailed analysis of variability within one of these oscillations records plant community cyclicity across the inception of the negative CIE. This short term cyclicity provides evidence that the replacement of warm termperate by winterwet floras occurred in a stepwise manner at the negative CIE suggesting cumulative atmospheric forcing. At <1mm scale, lamination within the negative CIE showed no obvious lithological or colour differences, and are not seasonal

  17. How do olivines record magmatic events? Insights from major and trace element zoning

    NASA Astrophysics Data System (ADS)

    de Maisonneuve, C. Bouvet; Costa, F.; Huber, C.; Vonlanthen, P.; Bachmann, O.; Dungan, M. A.

    2016-06-01

    Reconciling the diverse records of magmatic events preserved by multiple crystals and minerals in the same sample is often challenging. In the case of basaltic-andesites from Volcán Llaima (Chile), Mg zoning in olivine is always simpler than Ca zoning in plagioclase. A model that explains a number of chemical patterns is that Llaima magmas stall in the upper crust, where they undergo decompression crystallization and form crystal-mush bodies. Frequent magma inputs from deeper reservoirs provide the potential for remobilization and eruption. The records of multiple recharge events in Llaima plagioclase versus an apparent maximum of one such event in coexisting olivine are addressed by using trace element zoning in olivine phenocrysts. We have integrated elements that (1) respond to changes in magma composition due to recharge or mixing (Mg, Fe, Ni, Mn, ±Ca), with (2) elements that are incorporated during rapid, disequilibrium crystal growth (P, Ti, Sc, V, Al). A more complex history is obtained when these elements are evaluated considering their partition coefficients, diffusivities, and crystal growth rates. The olivine archive can then be reconciled with the plagioclase archive of magma reservoir processes. Olivine (and plagioclase) phenocrysts may experience up to three or more recharge events between nucleation and eruption. Diffusion modeling of major and trace element zoning in two dimensions using a new lattice Boltzmann model suggests that recharge events occur on the order of months to a couple of years prior to eruption, whereas crystal residence times are more likely to be on the order of a few years to decades.

  18. Two Types of Transpolar Arc Development, Event Studies with Data Set of ASTRID-2, DMSP, FAST, and SuperDARN

    NASA Technical Reports Server (NTRS)

    Narita, Yasuhito; Maezawa, Kiyoshi; Toshinori, Mukai; Kullen, A.; Ivchenko, N.; Marklund, G.; Frederick, R.; Carlson, C. W.; Spann, J. F.; Parks, G. K.; Six, N. Frank (Technical Monitor)

    2002-01-01

    Aurorae which appear in the polar cap are called transpolar arcs, polar cap arcs, sun-aligned arcs, or occasionally Theta-aurora because of its spatial distribution resembling Greek character 'Theta.' Morphology, IMF (Interplanetary Magnetic Field) relationship, and ionospheric convection patterns were studied in quest of mechanisms of transpolar arcs. Four events were analyzed: 1999/Jan/22/19:00 - 23/01:30 (1 event: a) 1999/Jan/24/06:00 - 10:00 (1 event: b) 1999/Feb/1 1/20:00 - 12/02:00 (2 events: c, d), with data set of ExB drift velocity data obtained by electric field measurements of ASTRID-2 and FAST, DMSP ion driftmeter data, and line-of-sight velocity data of SuperDARN. POLAR-UVI image data were used for spatial and temporal variations of transpolar arcs and ACE data set were used for investigation of IMF relationship. IMF-Bz was strongly positive (Bz from +8nT to +20 nT) during periods of all four transpolar arcs. In events (a),(b),(c), transpolar arcs appeared immediately after the direction of IMF turned northward, though IMF was fluctuating in event (b). A sudden increase of IMF-By, from +3nT to +18nT, was observed in event (d). Two different types of transpolar arc development were observed in POLAR-UVI: one which begins as a split from dawn or dusk sector of auroral oval and shifts poleward in event (a),(c),(d), and another which is initially a patch of auroral oval disturbed by substorm but develops as a transpolar arc, forming a growing finger-like shape from midnight sector (event b). Sunward flow, associated with positive IMF-Bz, were observed within newly-created polar caps in event (a),(c),(d). Not clear ionospheric convection pattern was seen across the polar cap arc in event (b) die to limitation of data set. In event (c), O+ with energy more than 1 keV were observed by FAST within a transpolar arc, suggesting that their origin be from plasma sheet. Transpolar arcs are thought to be projection of plasma sheet bifurcation into lobe regime. There

  19. Event related potentials recorded in patients with locked-in syndrome

    PubMed Central

    Onofrj, M.; Thomas, A.; Paci, C.; Scesi, M.; Tombari, R.

    1997-01-01

    OBJECTIVE—To determine the possibility of recording "cognitive" event related potentials (ERPs) in locked-in patients and therefore to determine whether ERPs can have a role in differential diagnosis of coma.
METHODS—ERPs to classic auditory or visual "odd ball paradigms" were recorded three to four days, seven to eight days, and 30 to 60days after admission to the intensive care unit, in four patients affected by basilar artery thrombembolism resulting in locked-in syndrome. Two patients (one 32 year old man, one 31 year old woman) could move the eyes laterally and vertically spontaneously and on command. One patient (a 39 year old man) had a "one and half syndrome", one patient (a 40 year old woman) could only elevate the left eyelid and eye. Results were compared with data from 30 age matched controls. In the last recording session a letter recognition paradigm was applied, in which ERPs were produced by the identification of letters forming a word. Results were compared with five age matched controls. Brainstem lesions extending to the pontomesencephalic junction were found on MRI and CT.
RESULTS—ERPs to the oddball paradigms were recorded in three patients in the first recording session, in all patients in the second recording session. Latency, amplitude, and topographic distribution of ERP components were inside normal limits. With the letter recognition paradigm the patients could emit a P3 component to correspond with target letters, with the same margin of error as controls.
CONCLUSION—It is possible to record ERPs in patients with locked-in syndrome shortly after the acute ischaemic lesion, and therefore to assess objectively cognitive activities. Furthermore the letter recognition paradigm could be implemented to facilitate linguistic communication with patients with locked-in syndrome.

 PMID:9416812

  20. Ramadan fasting is not usually associated with the risk of cardiovascular events: A systematic review and meta-analysis

    PubMed Central

    Turin, Tanvir C.; Ahmed, Salim; Shommu, Nusrat S.; Afzal, Arfan R.; Al Mamun, Mohammad; Qasqas, Mahdi; Rumana, Nahid; Vaska, Marcus; Berka, Noureddine

    2016-01-01

    Over one billion Muslims worldwide fast during the month of Ramadan. Ramadan fasting brings about some changes in the daily lives of practicing Muslims, especially in their diet and sleep patterns, which are associated with the risk of cardiovascular diseases. Over the years, many original studies have made the effort to identify the possible impact of the Ramadan fast on cardiovascular diseases. This systematic review and meta-analysis is an attempt to present the summary of key findings from those articles and an appraisal of selected literature. A systematic search using keywords of “;Ramadan fasting” and “;cardiovascular diseases” was conducted in primary research article and gray-literature repositories, in combination with hand searching and snow balling. Fifteen studies were finally selected for data extraction on the outcomes of stroke, myocardial infarction, and congestive heart failure. The analysis revealed that the incidence of cardiovascular events during the Ramadan fast was similar to the nonfasting period. Ramadan fast is not associated with any change in incidence of acute cardiovascular disease. PMID:27186152

  1. The Global Record of the Toarcian Ocean Anoxic Event: Perspectives from the Eastern Panthalassic Ocean

    NASA Astrophysics Data System (ADS)

    Gill, B. C.; Them, T. R., II; Caruthers, A. H.; Tulsky, E. T. T.; Martindale, R. C.; Marroquín, S. M.; Gröcke, D. R.

    2015-12-01

    Much of the debate surrounding Oceanic Anoxic Events (OAEs) concerns the regional versus global aspects of biogeochemical and environmental changes associated with it. Untangling local versus global aspects of OAEs remains a major challenge. This is particularly true for the Toarcian Oceanic Anoxic Event or T-OAE of the Early Jurassic (~182 million years ago) since few open ocean, deep-sea sedimentary records remain for this time interval. Much of the uncertainly surrounding the geochemical record of this event derives from the fact that the majority of the studied stratigraphic successions occur in Western Europe. These localities record the paleoceanographic conditions within the western Tethys Ocean and adjacent epeiric seas. To develop a greater understanding of the T-OAE we will present geochemical and biostratigraphic data from western North America (Alberta) that will enable us to access paleoceanographic changes associated with the T-OAE in the eastern Panthalassic Ocean. The Early Jurassic stratigraphic succession in Alberta consist of carbonate ramp facies that transition into basinal fine-grained siliciclastic facies. Ammonite biostratigraphy from this succession identifies the time interval spanning the Pliensbachian and Toarcian Stages (Carlottense, Kanense and Planulata zones of western North America). Organic carbon isotope data from the studied sections show the negative excursion that is now recognized globally to occur during the T-OAE. Locally, geochemical data indicate that the distal portions of a carbonate ramp and basinal facies were anoxic during the T-OAE and the carbonate factory appears to have been drowned at the onset of the T-OAE. In addition, sulfur isotope and iron speciation data will be presented from these successions to examine further the paleoceanographic changes of the Panthalassic Ocean in response to the T-OAE. Importantly, this Panthalassic succession provides an additional perspective for understanding global

  2. Selected plant microfossil records of the terminal Cretaceous event in terrestrial rocks, western North America

    USGS Publications Warehouse

    Nichols, D.J.

    2007-01-01

    Terrestrial or nonmarine rocks of western North America preserve a record of major disruption and permanent alteration of plant communities precisely at the K-T boundary - in the same rocks that preserve geochemical and mineralogical evidence of the terminal Cretaceous impact event. Plant microfossil records from many localities show abrupt disappearance of pollen species (= plant extinctions) closely associated with impact ejecta deposits containing iridium and shocked quartz. Localities discussed in detail in this review are Starkville South, Clear Creek North, Old Raton Pass, and Sugarite in the Raton Basin of Colorado and New Mexico; West Bijou in the Denver Basin, Colorado; Sussex in the Powder River Basin, Wyoming; and Pyramid Butte and Mud Buttes in the Williston Basin, North Dakota. ?? 2007 Elsevier B.V. All rights reserved.

  3. Toarcian oceanic anoxic event: An assessment of global causes using belemnite C isotope records

    NASA Astrophysics Data System (ADS)

    van de Schootbrugge, B.; McArthur, J. M.; Bailey, T. R.; Rosenthal, Y.; Wright, J. D.; Miller, K. G.

    2005-09-01

    Two hypotheses have been proposed to explain simultaneous large negative excursions (up to 7‰ PeeDee belemnite) in bulk carbonate (δ13Ccarb) and organic carbon isotope records (δ13Corg) from black shales marking the Toarcian oceanic anoxic event (T-OAE). The first explanation envisions recycling of dissolved inorganic carbon (DIC) with a light isotopic signature into the photic zone from the lower levels of a salinity-stratified water mass, essentially requiring a regional paleoceanographic driver of the carbon cycle. The second involves the rapid and massive dissociation of methane from gas hydrates that effectively renders the T-OAE a global perturbation of the carbon cycle. We present C isotope records from belemnites (δ13Cbel) sampled from two localities, calibrated with high-resolution ammonite biostratigraphy and Sr isotope stratigraphy, in Yorkshire (England) and Dotternhausen (Germany), that can be used to assess which model best explains the observed changes in carbon isotopes. Our records of the δ13C composition of belemnite calcite do not show the large negative C isotope excursions shown by coeval records of δ13C in sedimentary organic matter or bulk sedimentary carbonate. It follows that isotopically light carbon cannot have dominated the ocean-atmosphere carbon reservoir during the Toarcian OAE, as would be required were the methane release hypothesis correct. On the basis of an evaluation of available carbon isotope records we discuss a model in which the recycling of DIC from the deeper levels of a stratified water body, and shallowing of anoxic conditions into the photic zone, can explain all isotopic profiles. In particular, the model accounts for the higher C isotope values of belemnites that are characteristic of open ocean, well-mixed conditions, and the lower C isotope values of neritic phytoplankton communities that recorded the degree of density stratification and shallowing of anoxia in the photic zone.

  4. Network Event Recording Device: An automated system for Network anomaly detection, and notification. Draft

    SciTech Connect

    Simmons, D.G.; Wilkins, R.

    1994-09-01

    The goal of the Network Event Recording Device (NERD) is to provide a flexible autonomous system for network logging and notification when significant network anomalies occur. The NERD is also charged with increasing the efficiency and effectiveness of currently implemented network security procedures. While it has always been possible for network and security managers to review log files for evidence of network irregularities, the NERD provides real-time display of network activity, as well as constant monitoring and notification services for managers. Similarly, real-time display and notification of possible security breaches will provide improved effectiveness in combating resource infiltration from both inside and outside the immediate network environment.

  5. Former El Niño events: records from western South America

    NASA Astrophysics Data System (ADS)

    Ortlieb, Luc; Macharé, José

    1993-05-01

    The quasi-periodic alterations of the climate in South America and of the oceanographical conditions in the eastern Pacific Ocean, referred to as the "El Niño" phenomenon, are part of a global anomaly in the ocean-atmosphere interactive system (the El Niño-Southern Oscillation, ENSO). As this phenomenon is responsible for the major interannual climatic variability and has a great potential to document links between the atmospheric and oceanic circulations, it is important to understand its mechanism, its boundary conditions and the causes of the variations of its intensity. Many answers to such questions can be sought in the historical and geological record of El Niño occurrences. Former impacts of the El Niño phenomenon along the western coast of South America are documented by remnants of catastrophic rainfalls and associated river floods, records of lake salinity variations, beach ridge sequences and numerous evidences of alterations in the biotic and physical coastal environment. For the last millennium or so, relatively precise (although discontinuous) archaeological and historical data are available. Continuous, high-resolution, proxy records are provided by glaciological data (last 1500 yr) from the Quelccaya ice cap of southern Peru and are potentially available from coral cores from the Galapagos Islands. No marine varves that would permit a detailed and sequential study of El Niño-related oceanographic anomalies during the late Quaternary have yet been obtained off western South America. The reconstruction of the sequence of the main ENSO events during the last millennia is thus hampered by the fact that there are too few continuous records and that these have not necessarily registered every El Niño occurrence and/or the relative intensity of each event. The discontinuous records of major El Niño events are more numerous, but often lack the required chronological accuracy. Obviously, both series of data need to be cross-checked and compared with

  6. Parametric Dependence Of Fast-ion Transport Events On The National Spherical Torus Experiment

    SciTech Connect

    Fredrickson, Erik; Gorelenkov, N. N.; Podesta, M.; Gerhardt, S. P.; Bell, R. E.; Diallo, A.; LeBlanc, B.; Bortolon, A.

    2014-03-31

    Neutral-beam heated tokamak plasmas commonly have more than one third of the plasma kinetic energy in the non-thermal energetic beam ion population. This population of fast ions heats the plasma, provides some of the current drive, and can affect the stability (positively or negatively) of magnetohydrodynamic instabilities. This population of energetic ions is not in thermodynamic equilibrium, thus there is free-energy available to drive instabilities, which may lead to redistribution of the fast ion population. Understanding under what conditions beam-driven instabilities arise, and the extent of the resulting perturbation to the fast ion population, is important for predicting and eventually demonstrating non-inductive current ramp-up and sustainment in NSTX-U, as well as the performance of future fusion plasma experiments such as ITER. This paper presents an empirical approach towards characterizing the stability boundaries for some common energetic-ion-driven instabilities seen on NSTX.

  7. Recordings of mucociliary activity in vivo: benefit of fast Fourier transformation of the photoelectric signal.

    PubMed

    Lindberg, S; Cervin, A; Runer, T; Thomasson, L

    1996-09-01

    Investigations of mucociliary activity in vivo are based on photoelectric recordings of light reflections from the mucosa. The alterations in light intensity produced by the beating cilia are picked up by a photodetector and converted to photoelectric signals. The optimal processing of these signals is not known, but in vitro recordings have been reported to benefit from fast Fourier transformation (FFT) of the signal. The aim of the investigation was to study the effect of FFT for frequency analysis of photoelectric signals originating from an artificial light source simulating mucociliary activity or from sinus or nasal mucosa in vivo, as compared to a conventional method of calculating mucociliary wave frequency, in which each peak in the signal is interpreted as a beat (old method). In the experiments with the artificial light source, the FFT system was superior to the conventional method by a factor of 50 in detecting weak signals. By using FFT signal processing, frequency could be correctly calculated in experiments with a compound signal. In experiments in the rabbit maxillary sinus, the spontaneous variations were greater when signals were processed by FFT. The correlation between the two methods was excellent: r = .92. The increase in mucociliary activity in response to the ciliary stimulant methacholine at a dosage of 0.5 microgram/kg was greater measured with the FFT than with the old method (55.3% +/- 8.3% versus 43.0% +/- 8.2%, p < .05, N = 8), and only with the FFT system could a significant effect of a threshold dose (0.05 microgram/kg) of methacholine be detected. In the human nose, recordings from aluminum foil placed on the nasal dorsum and from the nasal septa mucosa displayed some similarities in the lower frequency spectrum (< 5 Hz) attributable to artifacts. The predominant cause of these artifacts was the pulse beat, whereas in the frequency spectrum above 5 Hz, results differed for the two sources of reflected light, the mean frequency in

  8. R2R Eventlogger: Community-wide Recording of Oceanographic Cruise Science Events

    NASA Astrophysics Data System (ADS)

    Maffei, A. R.; Chandler, C. L.; Stolp, L.; Lerner, S.; Avery, J.; Thiel, T.

    2012-12-01

    Methods used by researchers to track science events during a science research cruise - and to note when and where these occur - varies widely. Handwritten notebooks, printed forms, watch-keeper logbooks, data-logging software, and customized software have all been employed. The quality of scientific results is affected by the consistency and care with which such events are recorded and integration of multi-cruise results is hampered because recording methods vary widely from cruise to cruise. The Rolling Deck to Repository (R2R) program has developed an Eventlogger system that will eventually be deployed on most vessels in the academic research fleet. It is based on the open software package called ELOG (http://midas.psi.ch/elog/) originally authored by Stefan Ritt and enhanced by our team. Lessons have been learned in its development and use on several research cruises. We have worked hard to find approaches that encourage cruise participants to use tools like the eventlogger. We examine these lessons and several eventlogger datasets from past cruises. We further describe how the R2R Science Eventlogger works in concert with the other R2R program elements to help coordinate research vessels into a coordinated mobile observing fleet. Making use of data collected on different research cruises is enabled by adopting common ways of describing science events, the science instruments employed, the data collected, etc. The use of controlled vocabularies and the practice of mapping these local vocabularies to accepted oceanographic community vocabularies helps to bind shipboard research events from different cruises into a more cohesive set of fleet-wide events that can be queried and examined in a cross-cruise manner. Examples of the use of the eventlogger during multi-cruise oceanographic research programs along with examples of resultant eventlogger data will be presented. Additionally we will highlight the importance of vocabulary use strategies to the success of the

  9. Late Eocene Antarctic glacial events revealed by radiogenic isotope records from the Kerguelen Plateau

    NASA Astrophysics Data System (ADS)

    Smith, B. W.; Munn, G. H.; Bohaty, S. M.; Scher, H. D.

    2011-12-01

    Oxygen isotope measurements of benthic foraminifera in ODP Hole 738B (Kerguelen Plateau, Southern Ocean) show a 0.6% shift toward more positive values at ca. 37.1 Ma, near the middle/late Eocene boundary. The δ18O values during this cool event reach 2.2%, which may reflect a combination of both intermediate deep-water cooling and partial glaciation of East Antarctica. We conducted neodymium (Nd) isotope measurements of the terrigenous detrital fraction (i.e., decarbonated and leached) from the same samples used to construct the stable isotope record. Our results reveal a shift in the Nd isotope composition of fine-grained material deposited on Kerguelen Plateau that coincides with the δ18O excursion. The background ɛNd values (i.e., before and after the δ18O shift) are -12 ɛNd, consistent with regionally sourced sediment from along the East Antarctica margin (e.g., Wilkes Land, Prydz Bay). During the δ18O excursion at 37.1 Ma, there is transient decrease in ɛNd values to -15.5. These results strongly indicate that Kerguelen Plateau received an influx of detrital material from ancient sediment sources (i.e., with low ɛNd values), such as those found in nearby Prydz Bay. Our results support an increase in continental ice volume in East Antarctica during this event, resulting in enhanced rates of mechanical weathering. We have also documented a second cool event ca. 36.7 Ma, approximately 400 kyr after the 37 Ma event. Future efforts will focus on determining the timing of middle-to-late Eocene cooling episoides and further documenting changes in weathering during each of these events.

  10. Joint interpretation of high-precision tilt data and mining induced seismic events recorded underground in deep level gold mine in South Africa

    NASA Astrophysics Data System (ADS)

    Milev, Alexander; Share, Pieter; Durrheim, Ray; Naoi, Makoto; Nakatani, Masao; Yabe, Yasuo; Ogasawara, Hiroshi

    2013-04-01

    Seismicity associated with deep-level mining has for long been a problem, leading to rockburst and other similar hazards. Several studies have been completed in an attempt to minimize the total amount of seismicity. In this study high resolution measurements of ground tilting in combination with seismic monitoring is used to observe how the rock mass responds to mining. A good correspondence between the coseismic and the aseismic tilt was found. The rate of coseismic and aseismic tilt, as well as seismicity recorded by the mine seismic network, are approximately constant until the daily blasting time, which takes place from about 19:30 until shortly before 21:00. During the blasting time and the subsequent seismic events, the coseismic and aseismic tilt shows a rapid increase. In an attempt to distinguish between the different mechanisms of tilting two types of events were recognized. The "fast" seismic events characterized with sharp increase of the tilt during the seismic rupture and "slow" seismic events characterized by creep type post seismic deformations. Tilt behaviour before and after a seismic event was also analysed. The fact that no recognizable aftertilt was observed for more of the "fast" seismic events means that there is no gradual release of stress and an associated continuous strain rate change afterwards. It can therefore be concluded that a large seismic event causes a rapid change in the state of stress rather than a gradual change in the strain rate. The mechanism of the observed "slow" seismic events is more complicated. Although several explanations have been proposed, a suggestion for further work could be to investigate the presence of "slow" events in or after blasting time more closely. During the monitoring period a seismic event with MW 2.2 occurred in the vicinity of the instrumented site. This event was recorded by both the CSIR integrated monitoring system and JAGUARS acoustic emission network. More than 21,000 AE aftershocks were

  11. On the fingerprint of ssw events in infrasound recordings at IMS stations

    NASA Astrophysics Data System (ADS)

    Ceranna, Lars; Pilger, Christoph; Ross, Ole; Le Pichon, Alexis

    2013-04-01

    It has been recently shown that sudden stratospheric warming (ssw) events have an impact on the detection of coherent infrasonic waves at dedicated arrays (e.g., Evers & Siegmund, 2009). During ssw events the polar vortex of prevailing stratospheric westerly winds in a winter hemisphere abruptly slows down or even reverses its direction along with an increase of stratospheric temperatures up to several tens of °C. Since infrasound arrays are mostly recording signals ducted in stratospheric wave-guides, such antennas are sensitive to changes in effective sound speed profiles - temperature plus wind speed in direction of propagation. Considering continuous infrasonic waves emitted by ocean swell (microbaroms), volcanoes or even anthropogenic sources as flares, a gap or a change in the back-azimuth of these detected signals can be observed at arrays. For the compliances with the verification of the Comprehensive Nuclear-Test-Ban Treaty a global network of 60 infrasound stations is under construction as a part of the International Monitoring System (IMS); whereas 45 have already been installed. Analysis of waveform data recorded at these stations has demonstrated the capability of infrasound as a supplementary tool for remote sensing of the atmosphere. In our study we compare the re-analysis, using PMCC, of more than five years of continuous data at all available sites (see Matoza et al., 2013) with atmospheric descriptions provided by the EMCWF. We present a synoptic view of the fingerprint of ssw events in detection of coherent signals at IMS infrasound stations both on northern and southern hemisphere, covering the full latitude range from Antarctica to Greenland.

  12. On the fingerprint of ssw events in infrasound recordings at IMS stations

    NASA Astrophysics Data System (ADS)

    Ceranna, L.; Le Pichon, A.; Pilger, C.; Ross, O.

    2013-12-01

    It has been recently shown that sudden stratospheric warming (ssw) events have an impact on the detection of coherent infrasonic waves at dedicated arrays (e.g., Evers & Siegmund, 2009). During ssw events the polar vortex of prevailing stratospheric westerly winds in a winter hemisphere abruptly slows down or even reverses its direction along with an increase of stratospheric temperatures up to several tens of °C. Since infrasound arrays are mostly recording signals ducted in stratospheric wave-guides, such antennas are sensitive to changes in effective sound speed profiles - temperature plus wind speed in direction of propagation. Considering continuous infrasonic waves emitted by ocean swell (microbaroms), volcanoes or even anthropogenic sources as flares, a gap or a change in the back-azimuth of these detected signals can be observed at arrays. For the compliances with the verification of the Comprehensive Nuclear-Test-Ban Treaty a global network of 60 infrasound stations is under construction as a part of the International Monitoring System (IMS); whereas 45 have already been installed. Analysis of waveform data recorded at these stations has demonstrated the capability of infrasound as a supplementary tool for remote sensing of the atmosphere. In our study we compare the re-analysis, using PMCC, of more than five years of continuous data at all available sites (see Matoza et al., 2013) with atmospheric descriptions provided by the EMCWF. We present a synoptic view of the fingerprint of ssw events in detection of coherent signals at IMS infrasound stations both on northern and southern hemisphere, covering the full latitude range from Antarctica to Greenland.

  13. Digitized pressure-time records, selected nuclear events. Technical report, 1 September 1982-1 April 1986

    SciTech Connect

    McMullan, F.W.; Bryant, E.J.

    1986-04-30

    Pressure-time records are presented for selected atmospheric nuclear events. The records were extracted from published test reports, digitized, and given uniform pressure-time scales for a given event and a given range to permit easier comparison. Data include p-t, q-t, p(tot)-t, Mach No-t, and Impulse-t as appropriate. Selected data were scaled to 1 kT.

  14. The surface of Mars: An unusual laboratory that preserves a record of catastrophic and unusual events

    USGS Publications Warehouse

    Chapman, M.G.

    2009-01-01

    Catastrophic and unusual events on Earth such as bolide impacts, megafloods, supereruptions, flood volcanism, and subice volcanism may have devastating effects when they occur. Although these processes have unique characteristics and form distinctive features and deposits, we have diffi culties identifying them and measuring the magnitude of their effects. Our diffi culties with interpreting these processes and identifying their consequences are understandable considering their infrequency on Earth, combined with the low preservation potential of their deposits in the terrestrial rock record. Although we know these events do happen, they are infrequent enough that the deposits are poorly preserved on the geologically active face of the Earth, where erosion, volcanism, and tectonism constantly change the surface. Unlike the Earth, on Mars catastrophic and unusual features are well preserved because of the slow modifi cation of the surface. Signifi cant precipitation has not occurred on Mars for billions of years and there appears to be no discrete crustal plates to have undergone subduction and destruction. Therefore the ancient surface of Mars preserves geologic features and deposits that result from these extraordinary events. Also, unlike the other planets, Mars is the most similar to our own, having an atmosphere, surface ice, volcanism, and evidence of onceflowing water. So although our understanding of precursors, processes, and possible biological effects of catastrophic and unusual processes is limited on Earth, some of these mysteries may be better understood through investigating the surface of Mars. ?? 2009 The Geological Society of America.

  15. A brittle failure model for long-period seismic events recorded at Turrialba Volcano, Costa Rica

    NASA Astrophysics Data System (ADS)

    Eyre, Thomas S.; Bean, Christopher J.; De Barros, Louis; Martini, Francesca; Lokmer, Ivan; Mora, Mauricio M.; Pacheco, Javier F.; Soto, Gerardo J.

    2015-03-01

    A temporary seismic network, consisting of 23 broadband and six short-period stations, was installed in a dense network at Turrialba Volcano, Costa Rica, between 8 March and 4 May 2011. During this time 513 long-period (LP) events were observed. Due to their pulse-like waveforms, the hypothesis that the events are generated by a slow-failure mechanism, based on a recent new model by Bean et al. (2014), is tested. A significant number (107) of the LPs are jointly inverted for their source locations and mechanisms, using full-waveform moment tensor inversion. The locations are mostly shallow, with depths < 800 m below the active Southwest Crater. The results of the decompositions of the obtained moment tensor solutions show complex source mechanisms, composed of high proportions of isotropic and low, but seemingly significant, proportions of compensated linear vector dipole and double-couple components. It is demonstrated that this can be explained as mode I tensile fracturing with a strong shear component. The source mechanism is further investigated by exploring scaling laws within the data. The LPs recorded follow relationships very similar to those of conventional earthquakes, exhibiting frequency-magnitude and corner frequency versus magnitude relationships that can be explained by brittle failure. All of these observations indicate that a slow-failure source model can successfully describe the generation of short-duration LP events at Turrialba Volcano.

  16. Fast transient absorption spectroscopy of the early events in photoexcited chiral benzophenone naphthalene dyads

    NASA Astrophysics Data System (ADS)

    Perez-Ruiz, Raul; Groeneveld, Michiel; van Stokkum, Ivo H. M.; Tormos, Rosa; Williams, René M.; Miranda, Miguel A.

    2006-09-01

    Photoinduced intra-molecular energy transfer in two ketoprofen(KP)-naproxol(NPX) diastereomers proceeds via two pathways. Very fast singlet-triplet energy transfer ( k = 1.2 × 10 11 s -1) from KP to NPX occurs for a small percentage (6%) and the major pathway is triplet-triplet energy transfer ( k ˜ 3 × 10 9 s -1). This was shown with femtosecond transient absorption spectroscopy and global and target analysis. Whereas the NPX triplet decay is strongly stereospecific (ratio of 1.6), the NPX triplet state formation for both dyads is very similar (ratio of 1 for the fast process and 1.2 for the slower process).

  17. Two Types of Transpolar Arc Development, Event Studies With Data Set of Astrid-2, Dmsp, Fast, and Superdarn

    NASA Astrophysics Data System (ADS)

    Narita, Y.; Maezawa, K.; Kullen, A.; Ivchenko, N.; Marklund, G.; Carlson, C. W.; Spann, J. F.; Parks, G. K.; Superdarn Team

    Auroras which appear in the polar cap are called transpolar arcs, polar cap arcs, sun- aligned arcs, or occasionally Theta-aurora because of its spatial distribution resem- bling Greek character 'Theta.' Morphology, IMF(Interplanetary Magnetic Field) rela- tionship, and ionospheric convection patterns were studied in quest of mechanisms of transpolar arcs. Four events were analyzed: 1999/Jan/22/19:00 - 23/01:30 (1 event: a) 1999/Jan/24/06:00 - 10:00 (1 event: b) 1999/Feb/11/20:00 - 12/02:00 (2 events: c, d) , with data set of ExB drift velocity data obtained by electric field measurements of ASTRID-2 and FAST, DMSP ion driftmeter data, and line-of- sight velocity data of SuperDARN. POLAR-UVI image data were used for spatial and temporal variations of transpolar arcs and ACE data set were used for investigation of IMF relationship. IMF-Bz was strongly positive (Bz from +8nT to +20 nT) during periods of all four transpolar arcs. In events (a),(b),(c), transpolar arcs appeared immediately after the direction of IMF turned northward, though IMF was fluctuating in event (b). A sudden increase of IMF-By, from +3nT to +18nT, was observed in event (d). Two different types of transpolar arc development were observed by POLAR-UVI: one which begins as a split from dawn or dusk sector of auroral oval and shifts poleward in events (c),(d); another which is initially a patch of auroral oval disturbed by substorm but develops as a transpolar arc, forming a growing finger-like shape from midnight sector in event (b). Sunward flow, associated with positive IMF-Bz, were observed within newly-created polar caps in events (a),(c),(d). Not clear ionospheric convection pattern was seen across the transpolar arc in event (b) due to limitation of data set. Isotropic ions with energy more than 1 keV were observed within transpolar arcs. From these 1 observations it is concluded that the origin of transpolar arcs is from the plasma sheet. This is consistent with the view that transpolar

  18. Multifocal fluorescence microscope for fast optical recordings of neuronal action potentials.

    PubMed

    Shtrahman, Matthew; Aharoni, Daniel B; Hardy, Nicholas F; Buonomano, Dean V; Arisaka, Katsushi; Otis, Thomas S

    2015-02-01

    In recent years, optical sensors for tracking neural activity have been developed and offer great utility. However, developing microscopy techniques that have several kHz bandwidth necessary to reliably capture optically reported action potentials (APs) at multiple locations in parallel remains a significant challenge. To our knowledge, we describe a novel microscope optimized to measure spatially distributed optical signals with submillisecond and near diffraction-limit resolution. Our design uses a spatial light modulator to generate patterned illumination to simultaneously excite multiple user-defined targets. A galvanometer driven mirror in the emission path streaks the fluorescence emanating from each excitation point during the camera exposure, using unused camera pixels to capture time varying fluorescence at rates that are ∼1000 times faster than the camera's native frame rate. We demonstrate that this approach is capable of recording Ca(2+) transients resulting from APs in neurons labeled with the Ca(2+) sensor Oregon Green Bapta-1 (OGB-1), and can localize the timing of these events with millisecond resolution. Furthermore, optically reported APs can be detected with the voltage sensitive dye DiO-DPA in multiple locations within a neuron with a signal/noise ratio up to ∼40, resolving delays in arrival time along dendrites. Thus, the microscope provides a powerful tool for photometric measurements of dynamics requiring submillisecond sampling at multiple locations.

  19. Multifocal fluorescence microscope for fast optical recordings of neuronal action potentials.

    PubMed

    Shtrahman, Matthew; Aharoni, Daniel B; Hardy, Nicholas F; Buonomano, Dean V; Arisaka, Katsushi; Otis, Thomas S

    2015-02-01

    In recent years, optical sensors for tracking neural activity have been developed and offer great utility. However, developing microscopy techniques that have several kHz bandwidth necessary to reliably capture optically reported action potentials (APs) at multiple locations in parallel remains a significant challenge. To our knowledge, we describe a novel microscope optimized to measure spatially distributed optical signals with submillisecond and near diffraction-limit resolution. Our design uses a spatial light modulator to generate patterned illumination to simultaneously excite multiple user-defined targets. A galvanometer driven mirror in the emission path streaks the fluorescence emanating from each excitation point during the camera exposure, using unused camera pixels to capture time varying fluorescence at rates that are ∼1000 times faster than the camera's native frame rate. We demonstrate that this approach is capable of recording Ca(2+) transients resulting from APs in neurons labeled with the Ca(2+) sensor Oregon Green Bapta-1 (OGB-1), and can localize the timing of these events with millisecond resolution. Furthermore, optically reported APs can be detected with the voltage sensitive dye DiO-DPA in multiple locations within a neuron with a signal/noise ratio up to ∼40, resolving delays in arrival time along dendrites. Thus, the microscope provides a powerful tool for photometric measurements of dynamics requiring submillisecond sampling at multiple locations. PMID:25650920

  20. The record precipitation and flood event in Iberia in December 1876: description and synoptic analysis

    NASA Astrophysics Data System (ADS)

    Trigo, Ricardo; Varino, Filipa; Ramos, Alexandre; Valente, Maria; Zêzere, José; Vaquero, José; Gouveia, Célia; Russo, Ana

    2014-04-01

    The first week of December 1876 was marked by extreme weather conditions that affected the south-western sector of the Iberian Peninsula, leading to an all-time record flow in two large international rivers. As a direct consequence, several Portuguese and Spanish towns and villages located in the banks of both rivers suffered serious flood damage on 7 December 1876. These unusual floods were amplified by the preceding particularly autumn wet months, with October 1876 presenting extremely high precipitation anomalies for all western Iberia stations. Two recently digitised stations in Portugal (Lisbon and Evora), present a peak value on 5 December 1876. Furthermore, the values of precipitation registered between 28 November and 7 December were so remarkable that, the episode of 1876 still corresponds to the maximum average daily precipitation values for temporal scales between 2 and 10 days. Using several different data sources, such as historical newspapers of that time, meteorological data recently digitised from several stations in Portugal and Spain and the recently available 20th Century Reanalysis, we provide a detailed analysis on the socio-economic impacts, precipitation values and the atmospheric circulation conditions associated with this event. The atmospheric circulation during these months was assessed at the monthly, daily and sub-daily scales. All months considered present an intense negative NAO index value, with November 1876 corresponding to the lowest NAO value on record since 1865. We have also computed a multivariable analysis of surface and upper air fields in order to provide some enlightening into the evolution of the synoptic conditions in the week prior to the floods. These events resulted from the continuous pouring of precipitation registered between 28 November and 7 December, due to the consecutive passage of Atlantic low-pressure systems fuelled by the presence of an atmospheric-river tropical moisture flow over central Atlantic Ocean.

  1. Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates

    PubMed Central

    Silva, Rodrigo Tavares; Martinelli Filho, Martino; Peixoto, Giselle de Lima; de Lima, José Jayme Galvão; de Siqueira, Sérgio Freitas; Costa, Roberto; Gowdak, Luís Henrique Wolff; de Paula, Flávio Jota; Kalil Filho, Roberto; Ramires, José Antônio Franchini

    2015-01-01

    Background The recording of arrhythmic events (AE) in renal transplant candidates (RTCs) undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used. Objective We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR). Methods A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE. Results During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT) occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01–26.35; p = 0.002), and the duration of the PR interval (OR = 1.05; 95% CI, 1.02–1.08; p < 0.001) were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD) was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01–7.96; p = 0.041). Conclusions In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT. PMID:26351983

  2. Impedance changes recorded with scalp electrodes during visual evoked responses: implications for Electrical Impedance Tomography of fast neural activity.

    PubMed

    Gilad, O; Holder, D S

    2009-08-15

    Electrical Impedance Tomography (EIT) is a recently developed medical imaging method which could enable fast neural imaging in the brain by recording the resistance changes which occur as ion channels open during neuronal depolarization. In published studies in animal models with intracranial electrodes, changes of 0.005 to 3% have been reported but the amplitude of changes in the human is not known. The purpose of this work was to determine if resistance changes could be recorded non-invasively in humans during evoked activity which could form the basis for EIT of fast neural activity. Resistance was recorded with scalp electrodes during 2 Hz pattern visual evoked responses over 10 min using an insensible 1 Hz square wave constant current of 0.1-1 mA. Significant resistance decreases of 0.0010+/-0.0005% (0.30+/-0.15 microV, signal-to-noise ratio (SNR) of 2:1, n=16 recordings over 6 subjects) (mean+/-SE) were recorded. These are in broad agreement with modelling which estimated changes of 0.0039+/-0.0034% (1.03+/-0.75 microV) using an anatomically realistic finite element model. This is the first demonstration of such changes in humans and so encourages the belief that EIT could be used for neural imaging. Unfortunately, the signal-to-noise ratio was not sufficient to permit imaging at present because recording over multiple injection sites needed for imaging would require impractically long recording times. However, in the future, invasive imaging with intracranial electrodes in animal models or humans and improved signal processing or recording may still enable imaging; this would constitute a significant advance in neuroscience technology.

  3. [Clinical evaluation of ECG at the onset subjective symptoms using real-time analysis electrocardiograph (event recorder)].

    PubMed

    Takizawa, Yoshinori; Shimetani, Naoto; Uchiyama, Kenji; Takayanagi, Kan; Mori, Mikio

    2005-05-01

    Examination of patient complaining of palpitation, chest pain and chest discomfort is usually performed by 12-lead electrocardiograph. However, the recording time is short and there are few opportunities to capture an ECG demonstrating conditions during subjective symptoms. To investigate the cause, we need to obtain an ECG during subjective symptoms. Thus, we frequently use a Holter ECG, which can be recorded for 24 hours. However, some patients have a low frequency of subjective symptoms, which may not appear during a 24-hour examination. We used a real-time electrocardiograph (Event Recorder CG-6106 made by Card Guard Scientific Survival Limited) as a monitor during subjective symptoms. Thereafter, ECG findings at the onset of subjective symptoms could be analyzed in 30 patients who did not have a clear cardiac disease. In this examination, arrhythmia was recorded in 25 of 30 cases. Although in these cases ECG during subjective symptoms could not be captured even when Holter examination was performed several times ECG during subjective symptoms was captured using an Event Recorder. This method using an Event Recorder is simple and convenient, moreover, is considered very useful for investigation of subjective symptoms. In the future, the use of an Event Recorder for heart-health-care in the daily life of healthy people and/or cardiac disease patient is highly anticipated.

  4. Preliminary Record of Holocene Storm Events in the Finger Lakes, NY

    NASA Astrophysics Data System (ADS)

    Curtin, T. M.; Morgan, C. K.; Petrick, B. F.; Davin, L. I.; Rogers, C. E.; Crocker, M. L.; Loddengaard, K.; Baker, A. P.

    2006-12-01

    Terrigenous sediment deposited in three of the Finger Lakes of New York, Seneca, Keuka, and Canandaigua, preserve evidence for major storm events over the past ~13 ka. A combination of analytical techniques was used for ten cores, including visual inspection, magnetic susceptibility, loss-on-ignition, and grain size to identify these storm events. Storm layers are characterized by coincident coarse siliciclastic mean grain size, high % sand content, and more terrestrial plant macrofossils than the surrounding mud. The combination of sedimentological analyses with radiocarbon dating allows for development of a paleostorm chronology for each lake and comparison of the timing of the storm layers to determine if they were deposited synchronously or not. The number (10-31), thickness (0.1-6 cm), and grain size characteristics (1-37% sand) of the layers present in each core varies widely. As a result, single storm-related event deposition does not appear to have been synchronous among the three lake basins. However, there is temporal clustering of events. The greatest number of storm layers occurs in two distinct intervals, between ~13 and ~8.2 ka and ~4.6 and 0 ka. During the early to mid-Holocene, the number of events was high. We infer that a period of increased storminess occurred when the average climate of the region became warmer and wetter. Between ~8.2 and ~4.6 ka, when the average climate in North America was warm and dry, the number, thickness, and average mean grain size of the terrigenous layers decreased. After ~4.6 ka, the number of storms appears to have gradually increased as a result of a shift in the southern extent of the jet stream. The thickest, sandiest layers were deposited beginning at ~700 yrs BP and is associated with the climate of the Little Ice Age and Medieval Warming Period. The increase in the number, thickness, and sand content is especially apparent at ~290 yrs BP and is coincident the onset of widespread erosion due to deforestation

  5. Iridium abundance measurements across bio-event horizons in the geological record

    NASA Technical Reports Server (NTRS)

    Orth, C. J.; Attrep, M., Jr.

    1988-01-01

    Geochemical studies have been performed on thousands of rock samples collected across bio-event horizons in the fossil record using INAA for about 40 common and trace elements and radiochemical isolation procedures for Os, Ir, Pt, and Au on selected samples. These studies were begun soon after the Alvarez team announced their discovery of the Cretaceous-Tertiary (K-T) Ir anomaly in marine rock sequences in Europe. With their encouragement the Authors searched for the anomaly in nearby continental (freshwater coal swamp) deposits. In collaboration with scientists from the U.S.G.S. in Denver, the anomaly was located and it was observed that a floral crisis occurred at the same stratigraphic position as the Ir spike. Further work in the Raton Basin has turned up numerous well-preserved K-T boundary sections. Although the Authors have continued to study the K-T boundary and provide geochemical measurements for other groups trying to precisely locate it, the primary effort was turned to examining the other bio-events in the Phanerozoic, especially to those that are older than the terminal Cretaceous. A list of horizons that were examined in collaboration with paleontologists and geologists is given. Results are also given and discussed.

  6. Construction and laboratory test of a fibre optic sensor for rotational events recording

    NASA Astrophysics Data System (ADS)

    Kurzych, Anna; Krajewski, Zbigniew; Kowalski, Jerzy K.; Jaroszewicz, Leszek R.

    2016-05-01

    We present a novel and technically advanced system - Fibre-Optic System for Rotational Events & Phenomena Monitoring (FOSREM). It has been designed in order to register and monitor rotational events in seismological observatories, engineering constructions, mines and even on glaciers and in their vicinity. Its wide application field is a result of unique parameters and electronic solutions which give an opportunity to measure a component of rotation in the wide range of a signal amplitude from 10-8 rad/s to 10 rad/s, as well as a frequency from 0 Hz to the upper frequency between 2.56 Hz to 328.12 Hz. Moreover, the numerical analysis and simulations indicate that it keeps the theoretical sensitivity equal to 2·10-8 rad/s/Hz1/2. FOSREM is equipped with an advanced communication module which gives the possibility for a remote detection parameter control, as well as the recorded data receiving. It enables the sensor to assemble in any chosen place. In the paper we present laboratory investigations and tests which confirm the wide application field and practical aspects of FOSREM.

  7. Applying a New Event Detection Algorithm to an Ocean Bottom Seismometer Dataset Recorded Offshore Southern California

    NASA Astrophysics Data System (ADS)

    Bishop, J.; Kohler, M. D.; Bunn, J.; Chandy, K. M.

    2015-12-01

    A number of active southern California offshore faults are capable of M>6 earthquakes, and the only permanent Southern California Seismic Network stations that can contribute to ongoing, small-magnitude earthquake detection and location are those located on the coastline and islands. To obtain a more detailed picture of the seismicity of the region, an array of 34 ocean bottom seismometers (OBSs) was deployed to record continuous waveform data off the coast of Southern California for 12 months (2010-2011) as part of the ALBACORE (Asthenospheric and Lithospheric Broadband Architecture from the California Offshore Region Experiment) project. To obtain a local event catalog based on OBS data, we make use of a newly developed data processing platform based on Python. The data processing procedure comprises a multi-step analysis that starts with the identification of significant signals above the time-adjusted noise floor for each sensor. This is followed by a time-dependent statistical estimate of the likelihood of an earthquake based on the aggregated signals in the array. For periods with elevated event likelihood, an adaptive grid-fitting procedure is used that yields candidate earthquake hypocenters with confidence estimates that best match the observed sensor signals. The results are validated with synthetic travel times and manual picks. Using results from ALBACORE, we have created a more complete view of active faulting in the California Borderland.

  8. Calculations of the FLAX events with comparisons to particle velocity data recorded at low stress

    SciTech Connect

    Rambo, J.

    1993-09-01

    The FLAX event, fired in 1972, produced two particle velocity data sets from two devices in the same hole, U2dj. The data are of interest because they contain verification of focusing of a shock wave above the water table. The FLAX data show the peak velocity attenuation from the device buried in saturated tuff are different from those emanating from the upper device buried in porous alluvium. The attenuations of the peaks are different in regions traversed by both waves traveling at the same sound speed and measured by the same particle velocity gages. The attenuation rate from the lower device is due to 2-D effects attributed to wave focusing above the water table and is a feature that should be captured by 2-D calculations. LLNL`s KDYNA calculations used for containment analyses have utilized a material model initially developed by Butkovich, which estimates strength and compressibility based on gas porosity, total porosity, and water content determined from geophysical measurements. Unfortunately, the material model estimates do not correctly model the more important details of strength and compressibility used for matching the velocity data. The velocity gage data contain information that can be related to the strength properties of the medium, provided that there are more than two gages recording in the stress region of plastic deformation of the material. A modification to Butkovich`s model incorporated approximate strengths derived from the data. The mechanisms of focusing will be discussed and will incorporate additional information from the TYBO event.

  9. Fast vision through frameless event-based sensing and convolutional processing: application to texture recognition.

    PubMed

    Perez-Carrasco, Jose Antonio; Acha, Begona; Serrano, Carmen; Camunas-Mesa, Luis; Serrano-Gotarredona, Teresa; Linares-Barranco, Bernabe

    2010-04-01

    Address-event representation (AER) is an emergent hardware technology which shows a high potential for providing in the near future a solid technological substrate for emulating brain-like processing structures. When used for vision, AER sensors and processors are not restricted to capturing and processing still image frames, as in commercial frame-based video technology, but sense and process visual information in a pixel-level event-based frameless manner. As a result, vision processing is practically simultaneous to vision sensing, since there is no need to wait for sensing full frames. Also, only meaningful information is sensed, communicated, and processed. Of special interest for brain-like vision processing are some already reported AER convolutional chips, which have revealed a very high computational throughput as well as the possibility of assembling large convolutional neural networks in a modular fashion. It is expected that in a near future we may witness the appearance of large scale convolutional neural networks with hundreds or thousands of individual modules. In the meantime, some research is needed to investigate how to assemble and configure such large scale convolutional networks for specific applications. In this paper, we analyze AER spiking convolutional neural networks for texture recognition hardware applications. Based on the performance figures of already available individual AER convolution chips, we emulate large scale networks using a custom made event-based behavioral simulator. We have developed a new event-based processing architecture that emulates with AER hardware Manjunath's frame-based feature recognition software algorithm, and have analyzed its performance using our behavioral simulator. Recognition rate performance is not degraded. However, regarding speed, we show that recognition can be achieved before an equivalent frame is fully sensed and transmitted.

  10. High fold computer disk storage DATABASE for fast extended analysis of γ-rays events

    NASA Astrophysics Data System (ADS)

    Stézowski, O.; Finck, Ch.; Prévost, D.

    1999-03-01

    Recently spectacular technical developments have been achieved to increase the resolving power of large γ-ray spectrometers. With these new eyes, physicists are able to study the intricate nature of atomic nuclei. Concurrently more and more complex multidimensional analyses are needed to investigate very weak phenomena. In this article, we first present a software (DATABASE) allowing high fold coincidences γ-rays events to be stored on hard disk. Then, a non-conventional method of analysis, anti-gating procedure, is described. Two physical examples are given to explain how it can be used and Monte Carlo simulations have been performed to test the validity of this method.

  11. Comparison of Offshore Turbidite records and Lake Disturbance Events at the Latitude of Seattle, Washington

    NASA Astrophysics Data System (ADS)

    Galer, S.; Goldfinger, C.; Morey, A. E.; Black, B.; Romsos, C.; Beeson, J. W.; Erhardt, M.

    2014-12-01

    We are investigating the paleoseismic history of northern Washington using offshore turbidite cores and lake sediments collected from forearc lakes along a transect from offshore to Seattle, Washington. Additional offshore cores, ash determinations and heavy mineral analysis flesh out the turbidite stratigraphy off northern Washington, and support 3-5 proximal turbidites in northern Washington canyons (see Adams, 1990) in addition to the 19 regionally correlated beds. Onshore, we have cored multiple lakes including (west to east) Beaver, Leland, Tarboo, Hall, Sawyer, and Wapato, east of the Cascades, and collected multibeam bathymetry, backscatter and chirp subbottom data. These lakes are small (2-113 ha), 6-18 m deep, and are all kettle lakes except Beaver Lake (landslide-dammed) and Wapato Lake, a glacial scour. These lakes were selected for their limited outside sediment sources and low sensitivity to ground shaking. The sedimentology is mostly organic-rich gyttja. All lakes contain the Mazama ash based on its similar depth occurrence in previously published cores and new EMP analysis. Computed Tomography (CT) density, gamma density, and magnetic susceptibility (ms) data show there is more stratigraphic variability than is visually apparent. Low-energy disturbance events are apparent in the stratigraphy of all lakes (except Hall) as increases in clastics, density, and ms. The number of post Mazama disturbance events is similar to the number of expected great earthquakes found offshore and onshore, though definition of the boundaries of the lake events is much less clear. Initial radiocarbon results and preliminary correlations along this 185 km transect show strong similarities in stratigraphic records between these cores over the past ~7600 years, anchored by the Mazama tephra. Preliminary comparisons with offshore cores show a striking similarity in downcore variability in physical properties. Given the evidence for earthquake origin for the offshore cores

  12. Danngarrd-Oscar events recorded in a terrestrial sequence in central British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Ward, B. C.; Geertsema, M.; Telka, A.; Mathewes, R.

    2012-12-01

    Danngarrd-Oscar events recorded in the GISP2 Greenland Ice Core. The increasingly dry and cold conditions indicated by the macrofossil assemblage likely reflect the growth of ice in the Coast Mountains that would reduce the availability of moisture to the Interior Plateau from Pacific air masses. This is confirmed by reconstruction of the growth of the Cordilleran Ice Sheet during the Late Wisconsinan based on published radiocarbon dates.

  13. A Comparison of Reliability Measures for Continuous and Discontinuous Recording Methods: Inflated Agreement Scores with Partial Interval Recording and Momentary Time Sampling for Duration Events

    ERIC Educational Resources Information Center

    Rapp, John T.; Carroll, Regina A.; Stangeland, Lindsay; Swanson, Greg; Higgins, William J.

    2011-01-01

    The authors evaluated the extent to which interobserver agreement (IOA) scores, using the block-by-block method for events scored with continuous duration recording (CDR), were higher when the data from the same sessions were converted to discontinuous methods. Sessions with IOA scores of 89% or less with CDR were rescored using 10-s partial…

  14. Coherent Events and Spectral Shape at Ion Kinetic Scales in the Fast Solar Wind Turbulence

    NASA Astrophysics Data System (ADS)

    Lion, Sonny; Alexandrova, Olga; Zaslavsky, Arnaud

    2016-06-01

    In this paper we investigate spectral and phase coherence properties of magnetic fluctuations in the vicinity of the spectral transition from large, magnetohydrodynamic to sub-ion scales using in situ measurements of the Wind spacecraft in a fast stream. For the time interval investigated by Leamon et al. (1998) the phase coherence analysis shows the presence of sporadic quasi-parallel Alfvén ion cyclotron (AIC) waves as well as coherent structures in the form of large-amplitude, quasi-perpendicular Alfvén vortex-like structures and current sheets. These waves and structures importantly contribute to the observed power spectrum of magnetic fluctuations around ion scales; AIC waves contribute to the spectrum in a narrow frequency range whereas the coherent structures contribute to the spectrum over a wide frequency band from the inertial range to the sub-ion frequency range. We conclude that a particular combination of waves and coherent structures determines the spectral shape of the magnetic field spectrum around ion scales. This phenomenon provides a possible explanation for a high variability of the magnetic power spectra around ion scales observed in the solar wind.

  15. Fast oscillations in cortical-striatal networks switch frequency following rewarding events and stimulant drugs

    PubMed Central

    Berke, J.D.

    2009-01-01

    Oscillations may organize communication between components of large-scale brain networks. Although gamma-band oscillations have been repeatedly observed in cortical-basal ganglia circuits, their functional roles are not yet clear. Here I show that, in behaving animals, distinct frequencies of ventral striatal local field potential oscillations show coherence with different cortical inputs. ~50Hz gamma oscillations that normally predominate in awake ventral striatum are coherent with piriform cortex, while ~80-100Hz high-gamma oscillations are consistently coherent with frontal cortex. Within striatum, entrainment to gamma rhythms is selective to fast-spiking interneurons (FSIs), with distinct FSI populations entrained to different gamma frequencies. Administration of the psychomotor stimulant amphetamine or the dopamine agonist apomorphine causes a prolonged decrease in ~50Hz power and increase in ~80-100Hz power. The same frequency switch is observed for shorter epochs spontaneously in awake, undrugged animals, and is consistently provoked for <1s following reward receipt. Individual striatal neurons can participate in these brief high-gamma bursts with, or without, substantial changes in firing rate. Switching between discrete oscillatory states may allow different modes of information processing during decision-making and reinforcement-based learning, and may also be an important systems-level process by which stimulant drugs affect cognition and behavior. PMID:19659455

  16. New stratigraphic and isotopic record of the Toarcian Oceanic Anoxic Event from Hungary

    NASA Astrophysics Data System (ADS)

    Müller, Tamás; Price, Gregory; Bajnai, Dávid; Nyerges, Anita; Pálfy, József; May, Zoltán

    2016-04-01

    In the Early Toarcian (˜183 Ma) major global environmental changes took place in the ocean-atmosphere system, including the widely discussed Toarcian Oceanic Anoxic Event (T-OAE). This phenomenon is characterized by strong perturbation of the carbon-cycle and other geochemical systems. A peculiar negative carbon-isotope excursion (CIE) is a hallmark of the event, reflecting the injection of large amount of isotopically light carbon into the ocean-atmosphere system, possible due to dissociation of gas-hydrate from shelf areas. This observed negative CIE and a subsequent broad positive anomaly could be also key signals for chemostratigraphical correlation. In our study we obtained new, high-resolution organic carbon isotope data from the Réka Valley section of the Mecsek Mts. in southern Hungary. The Mecsek Basin was located at the European margin where a thick Lower Jurassic succession of siliciclastic hemipelagic sediments is interrupted by 13 m of organic-rich black shales in the Lower Toarcian. The δ13Corg data from the Réka Valley section is characterized by very negative values (averaging -32), with apparently cyclic fluctuation. The shape of the δ13Corg shows that a continuous and complete record can be found in the Réka Valley and also suggests mixed features between the carbon isotope record of the NW European and Tethyan regions. We have also carried out high resolution handheld XRF analyzes to study cyclostratigraphic signals in the section. The distribution of four elements Ti, Ca, Si and Al were used in our studies beside the δ13Corg data. The duration for the negative shift at Réka Valley, calculated from XRF signals, is either 550-750 kyr, 200-275 kyr or 116-158 kyr, based on 100 kyr short eccentricity, 36.6 kyr obliquity or 21.1 kyr precession signals, respectively. Several previous studies concluded that the most probable astronomical forcing factor during the CIE of the Toarcian OAE is obliquity. Therefore, we assume a duration around 200

  17. Spectroscopic interpretation and velocimetry analysis of fluctuations in a cylindrical plasma recorded by a fast camera

    SciTech Connect

    Oldenbuerger, S.; Brandt, C.; Brochard, F.; Lemoine, N.; Bonhomme, G.

    2010-06-15

    Fast visible imaging is used on a cylindrical magnetized argon plasma produced by thermionic discharge in the Mirabelle device. To link the information collected with the camera to a physical quantity, fast camera movies of plasma structures are compared to Langmuir probe measurements. High correlation is found between light fluctuations and plasma density fluctuations. Contributions from neutral argon and ionized argon to the overall light intensity are separated by using interference filters and a light intensifier. Light emitting transitions are shown to involve a metastable neutral argon state that can be excited by thermal plasma electrons, thus explaining the good correlation between light and density fluctuations. The propagation velocity of plasma structures is calculated by adapting velocimetry methods to the fast camera movies. The resulting estimates of instantaneous propagation velocity are in agreement with former experiments. The computation of mean velocities is discussed.

  18. Spectroscopic interpretation and velocimetry analysis of fluctuations in a cylindrical plasma recorded by a fast camera.

    PubMed

    Oldenbürger, S; Brandt, C; Brochard, F; Lemoine, N; Bonhomme, G

    2010-06-01

    Fast visible imaging is used on a cylindrical magnetized argon plasma produced by thermionic discharge in the Mirabelle device. To link the information collected with the camera to a physical quantity, fast camera movies of plasma structures are compared to Langmuir probe measurements. High correlation is found between light fluctuations and plasma density fluctuations. Contributions from neutral argon and ionized argon to the overall light intensity are separated by using interference filters and a light intensifier. Light emitting transitions are shown to involve a metastable neutral argon state that can be excited by thermal plasma electrons, thus explaining the good correlation between light and density fluctuations. The propagation velocity of plasma structures is calculated by adapting velocimetry methods to the fast camera movies. The resulting estimates of instantaneous propagation velocity are in agreement with former experiments. The computation of mean velocities is discussed.

  19. Neogene paleoceanographic events recorded in an active-margin setting: Humboldt basin, California

    USGS Publications Warehouse

    McCrory, P.A.

    1990-01-01

    Recognition of North Pacific paleoceanographic events in the marginal Humboldt (Eel River) basin of northern California enables correlation of stratigraphic sections and development of a chronostratigraphy. Paleoclimatically related coiling shifts in Neogloboquadrina pachyderma (Ehrenberg) and benthic foraminiferal datums form the basis of the chronostratigraphy. Benthic foraminiferal datums are defined by the occurrence of selected benthic species and abundance maxima of benthic biofacies. The compiled chronostratigraphy is used to refine reconstructions of the depositional history of Humboldt basin. Paleoceanographic events, recognized by the distribution of benthic foraminiferal biofacies, are used to infer paleoceanographic history along the northeastern Pacific margin. The similarity in coiling curves of N. pachyderma from the marine sequence at DSDP Site 173 and the coastal Centerville Beach section of Humboldt basin and at other independently dated sites along the northeastern Pacific margin demonstrates that matching records of climatic oscillations is a reliable method of correlating marine sequences. Benthic fauna from the Centerville Beach section vary in phase with climatically related coiling shifts in N. pachyderma. In particular these data show an increase in displaced neritic fauna during inferred warm intervals and resurgence of deeper bathyal fauna during inferred cool events. Similar data are observed from the inland Eel River section, demonstrating that benthic foraminiferal trends recognized at Centerville Beach can be identified elsewhere in Humboldt basin. This in-phase benthic response to climatic fluctuations probably results from changes in vertical depth range of many benthic species in response to paleoclimatically related vertical changes in water-mass position. Depositional histories reconstructed for two key sites in southern Humboldt basin indicate low rates of sediment accumulation during early basin filling with hemipelagic

  20. Diamond Morphology: Link to Metasomatic Events in the Mantle or Record of Evolution of Kimberlitic Fluid?

    NASA Astrophysics Data System (ADS)

    Fedortchouk, Y.

    2009-05-01

    Morphology and surface features on diamonds show tremendous variation even within a single kimberlite body reflecting a complex history of growth and dissolution. But does the diamond surface record the conditions in the several mantle sources sampled by the rising kimberlite magma, or evolution of the fluid system in the kimberlite magma itself? To address this question I revised morphological classification of diamonds from several kimberlite pipes from EKATI Mine property, N.W.T., Canada. The novelty of the approach, compared to the existing classifications, is in utilizing a random but large dataset of diamond dissolution experiments accumulated by several researchers including myself. These experiments have shown that similar forms (e.g. trigon etch pits) can be produced in a variety of conditions and environments, whereas their shape and size would depend on the reactant. Similarly, different types of resorption features always form together and can be used for deriving the composition of oxidizing fluid. The proposed classification method is focused on relating various types of diamond surfaces to the composition and conditions of oxidizing media. The study uses parcels of micro-and macro-diamonds (total of 125 carats) from Misery, Grizzly, Leslie and Koala kimberlites, EKATI Mine property, Northwest Territories, Canada. Only octahedron and hexoctahedron diamonds were selected (total ~600 stones). Diamond surfaces were studied using an optical and Field- Emission Scanning Electron Microscope to define resorption elements - simple surface features. These elements were identified for each of the three categories: 1) present on octahedral faces (well-preserved diamonds), 2) present on hexoctahedral faces (rounded resorbed diamonds), and 3) frosting (micro-features). Consistent associations of several elements define Resorption Types of diamonds, which form during a single oxidizing event. We further relate these types to the composition of the C-H-O + chlorides

  1. Evaluation of the southern California seismic velocity models through simulation of recorded events

    NASA Astrophysics Data System (ADS)

    Taborda, Ricardo; Azizzadeh-Roodpish, Shima; Khoshnevis, Naeem; Cheng, Keli

    2016-06-01

    Significant effort has been devoted over the last two decades to the development of various seismic velocity models for the region of southern California, United States. These models are mostly used in forward wave propagation simulation studies, but also as base models for tomographic and source inversions. Two of these models, the community velocity models CVM-S and CVM-H, are among the most commonly used for this region. This includes two alternative variations to the original models, the recently released CVM-S4.26 which incorporates results from a sequence of tomographic inversions into CVM-S, and the user-controlled option of CVM-H to replace the near-surface profiles with a VS30-based geotechnical model. Although either one of these models is regarded as acceptable by the modeling community, it is known that they have differences in their representation of the crustal structure and sedimentary deposits in the region, and thus can lead to different results in forward and inverse problems. In this paper, we evaluate the accuracy of these models when used to predict the ground motion in the greater Los Angeles region by means of an assessment of a collection of simulations of recent events. In total, we consider 30 moderate-magnitude earthquakes (3.5 < Mw < 5.5) between 1998 and 2014, and compare synthetics with data recorded by seismic networks during these events. The simulations are done using a finite-element parallel code, with numerical models that satisfy a maximum frequency of 1 Hz and a minimum shear wave velocity of 200 m s-1. The comparisons between data and synthetics are ranked quantitatively by means of a goodness-of-fit (GOF) criteria. We analyse the regional distribution of the GOF results for all events and all models, and draw conclusions from the results and how these correlate to the models. We find that, in light of our comparisons, the model CVM-S4.26 consistently yields better results.

  2. Magnetoclimatology: Teleconnection between the Siberian loess record and North Atlantic Heinrich events

    NASA Astrophysics Data System (ADS)

    Evans, M. E.; Rutter, N. W.; Catto, N.; Chlachula, J.; Nyvlt, D.

    2003-06-01

    New environmental magnetic data from loess and paleosol successions in outcrops in the upper reaches of the Ob River drainage, southern Siberia, track the major climatic variations over the last glacial-interglacial cycle. Profiles of magnetic susceptibility and alternating deposition of loess and soil-formation events correspond to oxygen isotope stages 1 5. The magnetic-susceptibility data, in association with the stratigraphic succession, confirm that the wind-vigor magnetoclimatological model is a viable alternative to the classic pedogenic model. Interpretation of magnetic-susceptibility data from loess- paleosol successions must therefore consider eolian dynamics, available source materials, and transport directions, in addition to pedogenic processes. Rapid magnetic fluctuations are also observed. These are identified—for the first time in Siberian records—as the signature of the abrupt cold pulses responsible for the Heinrich layers in North Atlantic marine sediments. The data thus form a component of climatic teleconnections across the Northern Hemisphere, allowing correlations to be made among (1) Siberian magnetic susceptibility stratigraphy, (2) data recorded from other loess-paleosol successions in China, European Russia, Europe, and North America, (3) North Atlantic ice-rafted detritus, and (4) sea-surface temperatures derived from molecular stratigraphy of marine sediments off the northwest coast of Africa.

  3. Crash reconstruction and injury-mechanism analysis using event data recorder technology.

    PubMed

    Donnelly, B R; Galganski, R A; Lawrence, R D; Blatt, A

    2001-01-01

    Sophisticated onboard crash-event data recorders (EDRs) that log key vehicle dynamics information can be used to improve crash reconstruction, model occupant response, study the mechanisms of injury, and estimate occupant injury probabilities in near-real time. Such an EDR was developed and utilized as part of the Automatic Collision Notification (ACN) system for the National Highway Traffic Safety Administration. This paper presents the results of a study in which the reconstruction of an actual crash was augmented using EDR/ACN-supplied three-dimensional acceleration and other data in a vehicle occupant model configured using the Articulated Total Body (ATB) computer code. ATB-generated occupant-motion imagery and body-region acceleration response information provided valuable insights that permitted crash-reconstruction specialists to ascertain the true nature of the collision and identify the probable cause of an injury suffered by one of the victims. The authors also posit that the use of EDR data from an ACN-type system as inputs to occupant crash-response modeling may be someday support crash-victim emergency medical treatment and triage.

  4. SEPServer catalogues of solar energetic particle events at 1 AU based on STEREO recordings: 2007-2012

    NASA Astrophysics Data System (ADS)

    Papaioannou, A.; Malandraki, O. E.; Dresing, N.; Heber, B.; Klein, K.-L.; Vainio, R.; Rodríguez-Gasén, R.; Klassen, A.; Nindos, A.; Heynderickx, D.; Mewaldt, R. A.; Gómez-Herrero, R.; Vilmer, N.; Kouloumvakos, A.; Tziotziou, K.; Tsiropoula, G.

    2014-09-01

    The Solar Terrestrial Relations Observatory (STEREO) recordings provide an unprecedented opportunity to study the evolution of solar energetic particle (SEP) events from different observation points in the heliosphere, allowing one to identify the effects of the properties of the interplanetary magnetic field (IMF) and solar wind structures on the interplanetary transport and acceleration of SEPs. Two catalogues based on STEREO recordings, have been compiled as a part of the SEPServer project, a three-year collaborative effort of eleven European partners funded under the Seventh Framework Programme of the European Union (FP7/SPACE). In particular, two instruments on board STEREO have been used to identify all SEP events observed within the descending phase of solar cycle 23 and the rising phase of solar cycle 24 from 2007 to 2012, namely: the Low Energy Telescope (LET) and the Solar Electron Proton Telescope (SEPT). A scan of STEREO/LET protons within the energy range 6-10 MeV has been performed for each of the two STEREO spacecraft. We have tracked all enhancements that have been observed above the background level of this particular channel and cross-checked with available lists of interplanetary coronal mass ejections (ICMEs), stream interaction regions (SIRs), and shocks, as well as with the reported events in literature. Furthermore, parallel scanning of the STEREO near relativistic electrons has been performed in order to pinpoint the presence (or absence) of an electron event in the energy range of 55-85 keV, for all of the aforementioned proton events included in our lists. We provide the onset and peak time as well as the peak value of all events for both protons and electrons, the relevant solar associations in terms of electromagnetic emissions, soft and hard X-rays (SXRs and HXRs). Finally, a subset of events with clear recordings at both STEREO spacecraft is presented together with the parent solar events of these multispacecraft SEP events.

  5. Mass Mortality Events in the NW Adriatic Sea: Phase Shift from Slow- to Fast-Growing Organisms.

    PubMed

    Di Camillo, Cristina Gioia; Cerrano, Carlo

    2015-01-01

    Massive outbreaks are increasing all over the world, which are likely related to climate change. The North Adriatic Sea, a sub-basin of the Mediterranean Sea, is a shallow semi-closed sea receiving high nutrients inputs from important rivers. These inputs sustain the highest productive basin of the Mediterranean Sea. Moreover, this area shows a high number of endemisms probably due to the high diversity of environmental conditions and the conspicuous food availability. Here, we documented two massive mortalities (2009 and 2011) and the pattern of recovery of the affected biocoenoses in the next two years. Results show an impressive and fast shift of the benthic assemblage from a biocoenosis mainly composed of slow-growing and long-lived species to a biocoenosis dominated by fast-growing and short-lived species. The sponge Chondrosia reniformis, one of the key species of this assemblage, which had never been involved in previous massive mortality events in the Mediterranean Sea, reduced its coverage by 70%, and only few small specimens survived. All the damaged sponges, together with many associated organisms, were detached by rough-sea conditions, leaving large bare areas on the rocky wall. Almost three years after the disease, the survived specimens of C. reniformis did not increase significantly in size, while the bare areas were colonized by fast-growing species such as stoloniferans, hydrozoans, mussels, algae, serpulids and bryozoans. Cnidarians were more resilient than massive sponges since they quickly recovered in less than one month. In the study area, the last two outbreaks caused a reduction in the filtration efficiency of the local benthic assemblage by over 60%. The analysis of the times series of wave heights and temperature revealed that the conditions in summer 2011 were not so extreme as to justify severe mass mortality, suggesting the occurrence of other factors which triggered the disease. The long-term observations of a benthic assemblage in the

  6. Mass Mortality Events in the NW Adriatic Sea: Phase Shift from Slow- to Fast-Growing Organisms

    PubMed Central

    Di Camillo, Cristina Gioia; Cerrano, Carlo

    2015-01-01

    Massive outbreaks are increasing all over the world, which are likely related to climate change. The North Adriatic Sea, a sub-basin of the Mediterranean Sea, is a shallow semi-closed sea receiving high nutrients inputs from important rivers. These inputs sustain the highest productive basin of the Mediterranean Sea. Moreover, this area shows a high number of endemisms probably due to the high diversity of environmental conditions and the conspicuous food availability. Here, we documented two massive mortalities (2009 and 2011) and the pattern of recovery of the affected biocoenoses in the next two years. Results show an impressive and fast shift of the benthic assemblage from a biocoenosis mainly composed of slow-growing and long-lived species to a biocoenosis dominated by fast-growing and short-lived species. The sponge Chondrosia reniformis, one of the key species of this assemblage, which had never been involved in previous massive mortality events in the Mediterranean Sea, reduced its coverage by 70%, and only few small specimens survived. All the damaged sponges, together with many associated organisms, were detached by rough-sea conditions, leaving large bare areas on the rocky wall. Almost three years after the disease, the survived specimens of C. reniformis did not increase significantly in size, while the bare areas were colonized by fast-growing species such as stoloniferans, hydrozoans, mussels, algae, serpulids and bryozoans. Cnidarians were more resilient than massive sponges since they quickly recovered in less than one month. In the study area, the last two outbreaks caused a reduction in the filtration efficiency of the local benthic assemblage by over 60%. The analysis of the times series of wave heights and temperature revealed that the conditions in summer 2011 were not so extreme as to justify severe mass mortality, suggesting the occurrence of other factors which triggered the disease. The long-term observations of a benthic assemblage in the

  7. Mass Mortality Events in the NW Adriatic Sea: Phase Shift from Slow- to Fast-Growing Organisms.

    PubMed

    Di Camillo, Cristina Gioia; Cerrano, Carlo

    2015-01-01

    Massive outbreaks are increasing all over the world, which are likely related to climate change. The North Adriatic Sea, a sub-basin of the Mediterranean Sea, is a shallow semi-closed sea receiving high nutrients inputs from important rivers. These inputs sustain the highest productive basin of the Mediterranean Sea. Moreover, this area shows a high number of endemisms probably due to the high diversity of environmental conditions and the conspicuous food availability. Here, we documented two massive mortalities (2009 and 2011) and the pattern of recovery of the affected biocoenoses in the next two years. Results show an impressive and fast shift of the benthic assemblage from a biocoenosis mainly composed of slow-growing and long-lived species to a biocoenosis dominated by fast-growing and short-lived species. The sponge Chondrosia reniformis, one of the key species of this assemblage, which had never been involved in previous massive mortality events in the Mediterranean Sea, reduced its coverage by 70%, and only few small specimens survived. All the damaged sponges, together with many associated organisms, were detached by rough-sea conditions, leaving large bare areas on the rocky wall. Almost three years after the disease, the survived specimens of C. reniformis did not increase significantly in size, while the bare areas were colonized by fast-growing species such as stoloniferans, hydrozoans, mussels, algae, serpulids and bryozoans. Cnidarians were more resilient than massive sponges since they quickly recovered in less than one month. In the study area, the last two outbreaks caused a reduction in the filtration efficiency of the local benthic assemblage by over 60%. The analysis of the times series of wave heights and temperature revealed that the conditions in summer 2011 were not so extreme as to justify severe mass mortality, suggesting the occurrence of other factors which triggered the disease. The long-term observations of a benthic assemblage in the

  8. Two Extreme Climate Events of the Last 1000 Years Recorded in Himalayan and Andean Ice Cores: Impacts on Humans

    NASA Astrophysics Data System (ADS)

    Thompson, L. G.; Mosley-Thompson, E. S.; Davis, M. E.; Kenny, D. V.; Lin, P.

    2013-12-01

    In the last few decades numerous studies have linked pandemic influenza, cholera, malaria, and viral pneumonia, as well as droughts, famines and global crises, to the El Niño-Southern Oscillation (ENSO). Two annually resolved ice core records, one from Dasuopu Glacier in the Himalaya and one from the Quelccaya Ice Cap in the tropical Peruvian Andes provide an opportunity to investigate these relationships on opposite sides of the Pacific Basin for the last 1000 years. The Dasuopu record provides an annual history from 1440 to 1997 CE and a decadally resolved record from 1000 to 1440 CE while the Quelccaya ice core provides annual resolution over the last 1000 years. Major ENSO events are often recorded in the oxygen isotope, insoluble dust, and chemical records from these cores. Here we investigate outbreaks of diseases, famines and global crises during two of the largest events recorded in the chemistry of these cores, particularly large peaks in the concentrations of chloride (Cl-) and fluoride (Fl-). One event is centered on 1789 to 1800 CE and the second begins abruptly in 1345 and tapers off after 1360 CE. These Cl- and F- peaks represent major droughts and reflect the abundance of continental atmospheric dust, derived in part from dried lake beds in drought stricken regions upwind of the core sites. For Dasuopu the likely sources are in India while for Quelccaya the sources would be the Andean Altiplano. Both regions are subject to drought conditions during the El Niño phase of the ENSO cycle. These two events persist longer (10 to 15 years) than today's typical ENSO events in the Pacific Ocean Basin. The 1789 to 1800 CE event was associated with a very strong El Niño event and was coincidental with the Boji Bara famine resulting from extended droughts that led to over 600,000 deaths in central India by 1792. Similarly extensive droughts are documented in Central and South America. Likewise, the 1345 to 1360 CE event, although poorly documented

  9. Records of the paleoclimate during the fast transgression period (13 ka BP-8 ka BP) from the mud area on the inner shelf of the East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, S.

    2015-12-01

    A 35.30m-long core (MZ02) recovered from a water depth of 32.4m from the inner shelf mud deposit of the East China Sea was analyzed for sedimentary characteristics, color reflectance, clay mineral, and element geochemistry components as well as by AMS 14C dating to research the sedimentation rate, sediment provenance and paleocwan mountainous river and clay fralimate evolution during the fast transgression period in the study area. Rare earth element and clay mineral proxies indicated that the mixed provenance sediment accumulated in the foreshore-nearshore region at the beginning of the fast transgression period, with a higher sedimentation rate of 5.58m/ka. While from 9800-9500 a B.P., the sedimentation rate keep lower about 1.73m/ka, and the sediment provenance changed obviously, silt fraction were apt to Taiction prone to be transported from the Yangtze River. Multiple proxy system including sediment redness (a*), chemical index of alteration (CIA), clay mineral proxy (smectite/kaolinite), major and trace element proxy (CaO/MgO, Ba/Sr) also showed a good paleoclimate record during the fast transgression period, which could be divided into three units. All the proxies changed little during Unit I (13-11.3ka B.P.) and revealed the climate kept in a relative stable level. Obvious fluctuation happened in Unit II (11.3-10.1ka B.P.) and the temperature kept decreasing more than 1ka till the Younger Dryas event, showed a well regional response to global climate changes. While continuous warming trend resumed again in Unit III (10.1-8 ka B.P.), which may be the signal for Holocene warm period. In addition, we also found significant 80yr, 89yr and 100yr cycles in our CIA, CaO/MgO and Ba/Sr records that imply a possible solar influence on the regional climate changes during the fast transgression period. Keywords: East China Sea, provenance, transgression, mud deposit, late Pleistocene, paleoclimate

  10. An underestimated record breaking event - why summer 1540 was likely warmer than 2003

    NASA Astrophysics Data System (ADS)

    Wetter, O.; Pfister, C.

    2013-01-01

    The heat of summer 2003 in Western and Central Europe was claimed to be unprecedented since the Middle Ages on the basis of grape harvest data (GHD) and late wood maximum density (MXD) data from trees in the Alps. This paper shows that the authors of these studies overlooked the fact that the heat and drought in Switzerland in 1540 likely exceeded the amplitude of the previous hottest summer of 2003, because the persistent temperature and precipitation anomaly in that year, described in an abundant and coherent body of documentary evidence, severely affected the reliability of GHD and tree-rings as proxy-indicators for temperature estimates. Spring-summer (AMJJ) temperature anomalies of 4.7 °C to 6.8 °C being significantly higher than in 2003 were assessed for 1540 from a new long Swiss GHD series (1444 to 2011). During the climax of the heat wave in early August the grapes desiccated on the vine, which caused many vine-growers to interrupt or postpone the harvest despite full grape maturity until after the next spell of rain. Likewise, the leaves of many trees withered and fell to the ground under extreme drought stress as would usually be expected in late autumn. It remains to be determined by further research whether and how far this result obtained from local analyses can be spatially extrapolated. Based on the temperature estimates for Switzerland it is assumed from a great number of coherent qualitative documentary evidence about the outstanding heat drought in 1540 that AMJJ temperatures were likely more extreme in neighbouring regions of Western and Central Europe than in 2003. Considering the significance of soil moisture deficits for record breaking heat waves, these results still need to be validated with estimated seasonal precipitation. It is concluded that biological proxy data may not properly reveal record breaking heat and drought events. Such assessments thus need to be complemented with the critical study of contemporary evidence from

  11. The Early Toarcian Oceanic Anoxic Event: A Southern Hemisphere record from Chile

    NASA Astrophysics Data System (ADS)

    Fantasia, Alicia; Föllmi, Karl B.; Adatte, Thierry; Spangenberg, Jorge E.; Bernárdez, Enrique; Mattioli, Emanuela

    2016-04-01

    The Early Toarcian was marked by important environmental changes, marine oxygen deficiency and extensive organic-rich sediment deposition (T-OAE; ˜182 Ma, Early Jurassic). The T-OAE coincides with a marked negative carbon isotope excursion (CIE) recorded in marine carbonate, and marine and terrestrial organic carbon. This is commonly attributed to the massive release of isotopically light carbon to the atmospheric and oceanic reservoirs derived from the destabilization of methane hydrates from marine sediments and/or the emissions of thermogenic methane from the eruption of the Karoo-Ferrar LIP (e.g., Hesselbo et al., 2000; Kemp et al., 2005; Svensen et al., 2007; Mazzini et al., 2010). Moreover, in most documented marine sections, this episode is marked by a generalized crisis in carbonate production and marine invertebrate extinctions (e.g. Jenkyns, 1988; Röhl et al., 2005; Suan et al., 2001). Several studies of the T-OAE have been conducted on sediments in central and northwest Europe, but only few data are available from the Southern Hemisphere, leading to large uncertainty concerning the exact expression of this event in this part of the world. The aims of this study are to characterize the sediments deposited during the Andean equivalents of the tenuicostatum and falciferum European Zones and establish in which way the T-OAE affected this region. In the Early Jurassic, the Andean basin was in a back-arc setting with marine corridors connected to Panthalassa. In this study, we have generated new high-resolution sedimentological, geochemical and mineralogical data from the sections of El Peñon and Quebrada Asiento, located in Chile in the northeastern area of the city of Copiapó, Atacama region. The biostratigraphy of these sections has been studied by von Hillebrandt and Schidt-Effing (1981) and complemented here by a biostratigraphy based on calcareous nannofossils. The sections consist of a succession of marl, limestone and siltstone of Pliensbachian and

  12. Possible explanation of the correlations between events recorded by underground detectors during the Supernova 1987A explosion

    SciTech Connect

    Alexeyev, E. N.

    2010-02-15

    A possible explanation of the time correlations between the data from underground detectors (Baksan telescope, LSD, IMB, Kamiokande II) and from the Rome and Maryland gravitational-wave antennas obtained during the Supernova 1987A explosion is proposed. It is shown that the synchronization of the events recorded by various underground facilities could be produced by gravitational radiation from the Supernova.

  13. 26 CFR 301.9000-4 - Procedure in the event of a request or demand for IRS records or information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Procedure in the event of a request or demand... demand for IRS records or information. (a) Purpose and scope. This section prescribes procedures to be followed by IRS officers, employees and contractors upon receipt of a request or demand in matters in...

  14. Patient characteristics associated with venous thromboembolic events: a cohort study using pooled electronic health record data

    PubMed Central

    Foster, Wendy; Gilder, Jason; Love, Thomas E; Jain, Anil K

    2012-01-01

    Objective To demonstrate the potential of de-identified clinical data from multiple healthcare systems using different electronic health records (EHR) to be efficiently used for very large retrospective cohort studies. Materials and methods Data of 959 030 patients, pooled from multiple different healthcare systems with distinct EHR, were obtained. Data were standardized and normalized using common ontologies, searchable through a HIPAA-compliant, patient de-identified web application (Explore; Explorys Inc). Patients were 26 years or older seen in multiple healthcare systems from 1999 to 2011 with data from EHR. Results Comparing obese, tall subjects with normal body mass index, short subjects, the venous thromboembolic events (VTE) OR was 1.83 (95% CI 1.76 to 1.91) for women and 1.21 (1.10 to 1.32) for men. Weight had more effect then height on VTE. Compared with Caucasian, Hispanic/Latino subjects had a much lower risk of VTE (female OR 0.47, 0.41 to 0.55; male OR 0.24, 0.20 to 0.28) and African-Americans a substantially higher risk (female OR 1.83, 1.76 to 1.91; male OR 1.58, 1.50 to 1.66). This 13-year retrospective study of almost one million patients was performed over approximately 125 h in 11 weeks, part time by the five authors. Discussion As research informatics tools develop and more clinical data become available in EHR, it is important to study and understand unique opportunities for clinical research informatics to transform the scale and resources needed to perform certain types of clinical research. Conclusions With the right clinical research informatics tools and EHR data, some types of very large cohort studies can be completed with minimal resources. PMID:22759621

  15. The isotropic climatic records in the Alleroed-B{o}lling-Younger Dryas and post-Younger Dryas events

    SciTech Connect

    Epstein, S.

    1995-12-01

    This study compares isotope records of late glacial period climates from Greenland and Alaska. The isotopic composition of dated Alaskan wood samples was determined and compared to isotope data from the Greenland ice cap, pelagic foraminifera, and German pine trees. A time correspondence of large isotopic variations was observed, suggesting that the Allerod-Bolling and Younger Dryas events were widespread in the northern hemisphere, and not restricted to the North Atlantic region. In addition, data indicated that the Allerod-Bolling event was initiated by rapid cooling, and the Younger Dryas event by rapid warming in temperate zones. Consequently, isotopic oscillations recorded at Alaska and Greenland during the Glacial-Interglacial transition are not necessarily associated with temperature variations at those locations. 13 refs., 5 figs.

  16. Networks of recurrent events, a theory of records, and an application to finding causal signatures in seismicity.

    PubMed

    Davidsen, Jörn; Grassberger, Peter; Paczuski, Maya

    2008-06-01

    We propose a method to search for signs of causal structure in spatiotemporal data making minimal a priori assumptions about the underlying dynamics. To this end, we generalize the elementary concept of recurrence for a point process in time to recurrent events in space and time. An event is defined to be a recurrence of any previous event if it is closer to it in space than all the intervening events. As such, each sequence of recurrences for a given event is a record breaking process. This definition provides a strictly data driven technique to search for structure. Defining events to be nodes, and linking each event to its recurrences, generates a network of recurrent events. Significant deviations in statistical properties of that network compared to networks arising from (acausal) random processes allows one to infer attributes of the causal dynamics that generate observable correlations in the patterns. We derive analytically a number of properties for the network of recurrent events composed by a random process in space and time. We extend the theory of records to treat not only the variable where records happen, but also time as continuous. In this way, we construct a fully symmetric theory of records leading to a number of results. Those analytic results are compared in detail to the properties of a network synthesized from time series of epicenter locations for earthquakes in Southern California. Significant disparities from the ensemble of acausal networks that can be plausibly attributed to the causal structure of seismicity are as follows. (1) Invariance of network statistics with the time span of the events considered. (2) The appearance of a fundamental length scale for recurrences, independent of the time span of the catalog, which is consistent with observations of the "rupture length." (3) Hierarchy in the distances and times of subsequent recurrences. As expected, almost all of the statistical properties of a network constructed from a surrogate

  17. Measurement of patient safety: a systematic review of the reliability and validity of adverse event detection with record review

    PubMed Central

    Hanskamp-Sebregts, Mirelle; Zegers, Marieke; Vincent, Charles; van Gurp, Petra J; de Vet, Henrica C W; Wollersheim, Hub

    2016-01-01

    Objectives Record review is the most used method to quantify patient safety. We systematically reviewed the reliability and validity of adverse event detection with record review. Design A systematic review of the literature. Methods We searched PubMed, EMBASE, CINAHL, PsycINFO and the Cochrane Library and from their inception through February 2015. We included all studies that aimed to describe the reliability and/or validity of record review. Two reviewers conducted data extraction. We pooled κ values (κ) and analysed the differences in subgroups according to number of reviewers, reviewer experience and training level, adjusted for the prevalence of adverse events. Results In 25 studies, the psychometric data of the Global Trigger Tool (GTT) and the Harvard Medical Practice Study (HMPS) were reported and 24 studies were included for statistical pooling. The inter-rater reliability of the GTT and HMPS showed a pooled κ of 0.65 and 0.55, respectively. The inter-rater agreement was statistically significantly higher when the group of reviewers within a study consisted of a maximum five reviewers. We found no studies reporting on the validity of the GTT and HMPS. Conclusions The reliability of record review is moderate to substantial and improved when a small group of reviewers carried out record review. The validity of the record review method has never been evaluated, while clinical data registries, autopsy or direct observations of patient care are potential reference methods that can be used to test concurrent validity. PMID:27550650

  18. Geomorphological record of extreme wave events during Roman times in the Guadalquivir estuary (Gulf of Cadiz, SW Spain): An archaeological and paleogeographical approach

    NASA Astrophysics Data System (ADS)

    Rodríguez-Ramírez, Antonio; Villarías-Robles, Juan J. R.; Pérez-Asensio, José N.; Santos, Ana; Morales, Juan Antonio; Celestino-Pérez, Sebastián; León, Ángel; Santos-Arévalo, Francisco Javier

    2016-05-01

    Analysis of the geological record has made it possible to delimit for the Guadalquivir estuary the traces of extreme wave events (EWEs) during the Roman period in the Iberian Peninsula (218 BCE to 476 CE). The largest event occurred in the 2nd-3rd century CE. It generated clearly visible erosive effects in the coastal barriers, including washover fans and erosional scarps. In the inner estuary, however, the effects were minor: crevasse splays that broke levees and cheniers, as well as a residual sedimentary lag. The significant development of the spits protected the inner estuary from the marine incursion, which only caused a water level rise with low-regime waves. Correlation of the geomorphological and sedimentary marks left by this event with the archaeological and geological evidence of other events recognized elsewhere in the Gulf of Cadiz effectively argues for a tsunami as to the nature of the 2nd-3rd century CE event. Yet this and the other identified EWEs in the Guadalquivir estuary during the pre-Roman and the Roman period all fit a model of paleogeographic evolution dominated by processes of coastal progradation and estuarine infilling. Radiocarbon dating, geomorphological analysis, and historical references fail to warrant the so-called '218-209 BCE' Atlantic tsunami, as hypothesized in the received scientific literature. In pre-Roman and Roman times, human occupation at the mouth of the Guadalquivir River was strongly influenced by various geodynamic processes, the location of the settlements being contingent upon dependable, fast communication with the sea and, above all, upon adequate protection from EWEs, on the leeward side of spits. Progressive progradation of these coastal barriers combined with the gradual infilling of the estuary to make navigation to open sea increasingly difficult and, eventually, to result in the abandonment of settlements.

  19. Messinian Salinity Crisis - DREAM (Deep-sea Record of Mediterranean Messinian events) drilling projects

    NASA Astrophysics Data System (ADS)

    Lofi, Johanna; Camerlenghi, Angelo

    2014-05-01

    About 6 My ago the Mediterranean Sea was transformed into a giant saline basin. This event, commonly referred to as the Messinian salinity crisis (MSC), changed the chemistry of the global ocean and had a permanent impact on both the terrestrial and marine ecosystems of a huge area surrounding the Mediterranean area. The first fascinating MSC scenario was proposed following DSDP Leg XIII in 1970 and envisaged an almost desiccated deep Mediterranean basin with a dramatic ~1,500 m drop of sea level, the incision of deep canyons by rivers on the continental margins, and a final catastrophic flooding event when the connections between the Mediterranean Sea and the Atlantic were re-established ~5.33 My ago. In spite of 40 years of multi-disciplinary research conducted on the MSC, modalities, timing, causes, chronology and consequence at local and planetary scale are still not yet fully understood, and the MSC event remains one of the longest-living controversies in Earth Science. Key factor for the controversy is the lack of a complete record of the MSC preserved in the deepest Mediterranean basins. Anywhere else, the MSC mostly generated a sedimentary/time lag corresponding to a widespread erosion surface. Correlations with the offshore depositional units are thus complex, preventing the construction of a coherent scenario linking the outcropping MSC evaporites, the erosion on the margins, and the deposition of clastics and evaporites in the abyssal plains. Recent activity by various research groups in order to identify locations for multiple-site drilling (including riser-drilling) in the Mediterranean Sea that would contribute to solve the open questions still existing about the MSC has culminated in two DREAM Magellan+ Workshops held in 2013 and 2014. A strategy and work plan have been established in order to submit an IODP Multi-phase Drilling Project("Uncovering A Salt Giant")including several site-specific drilling proposals addressing different scientific

  20. The Early Toarcian Oceanic Anoxic Event and its sedimentary record in Switzerland

    NASA Astrophysics Data System (ADS)

    Fantasia, Alicia; Föllmi, Karl B.; Adatte, Thierry; Spangenberg, Jorge E.; Montero-Serrano, Jean-Carlos

    2015-04-01

    In the Jurassic period, the Early Toarcian Oceanic Anoxic Event (T-OAE), about 183 Ma ago, was a global perturbation of paleoclimatic and paleoenvironmental conditions. This episode was associated with a crisis in marine carbonate accumulation, climate warming, an increase in sea level, ocean acidification, enhanced continental weathering, whereas organic-rich sediments are noticeable for example in the Atlantic and in the Tethys. This episode is associated with a negative carbon excursion, which is recorded both in marine and terrestrial environments. The cause(s) of this environmental crisis remain(s) still controversial. Nevertheless, the development of negative δ13C excursions is commonly interpreted as due to the injection of isotopically-light carbon associated with gas hydrate dissociation, the thermal metamorphism of carbon-rich sediments and input of thermogenic and volcanogenic carbon related to the formation of the Karoo-Ferrar basaltic province in southern Gondwana (Hesselbo et al., 2000, 2007; Beerling et al., 2002; Cohen et al., 2004, 2007; McElwain et al., 2005, Beerling and Brentnall, 2007; Svensen et al., 2007; Hermoso et al., 2009, 2012; Mazzini et al., 2010). Several studies of the T-OAE have been conducted on sediments in central and northwest Europe, but only few data are available concerning the Swiss sedimentary records. Therefore, we focused on two sections in the Jura Plateau (canton Aargau): the Rietheim section (Montero-Serrano et al., submitted) and the Gipf section (current study). A multidisciplinary approach has been chosen and the tools to be used are based on sedimentological observations (sedimentary condensation, etc.), biostratigraphy, mineralogy (bulk-rock composition), facies and microfacies analysis (presence or absence of benthos), clay-mineralogy composition (climatic conditions), major and trace-element analyses (productivity, redox conditions, etc.), phosphorus (trophic levels, anoxia), carbon isotopes and organic

  1. Ultra-fast three terminal perpendicular spin-orbit torque MRAM (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Boulle, Olivier; Cubukcu, Murat; Hamelin, Claire; Lamard, Nathalie; Buda-Prejbeanu, Liliana; Mikuszeit, Nikolai; Garello, Kevin; Gambardella, Pietro; Langer, Juergen; Ocker, Berthold; Miron, Mihai; Gaudin, Gilles

    2015-09-01

    The discovery that a current flowing in a heavy metal can exert a torque on a neighboring ferromagnet has opened a new way to manipulate the magnetization at the nanoscale. This "spin orbit torque" (SOT) has been demonstrated in ultrathin magnetic multilayers with structural inversion asymmetry (SIA) and high spin orbit coupling, such as Pt/Co/AlOx multilayers. We have shown that this torque can lead to the magnetization switching of a perpendicularly magnetized nanomagnet by an in-plane current injection. The manipulation of magnetization by SOT has led to a novel concept of magnetic RAM memory, the SOT-MRAM, which combines non volatility, high speed, reliability and large endurance. These features make the SOT-MRAM a good candidate to replace SRAM for non-volatile cache memory application. We will present the proof of concept of a perpendicular SOT-MRAM cell composed of a Ta/FeCoB/MgO/FeCoB magnetic tunnel junction and demonstrate ultra-fast (down to 300 ps) deterministic bipolar magnetization switching. Macrospin and micromagnetic simulations including SOT cannot reproduce the experimental results, which suggests that additional physical mechanisms are at stacks. Our results show that SOT-MRAM is fast, reliable and low power, which is promising for non-volatile cache memory application. We will also discuss recent experiments of magnetization reversal in ultrathin multilayers Pt/Co/AlOx by very short (<200 ps) current pulses. We will show that in this material, the Dzyaloshinskii-Moryia interaction plays a key role in the reversal process.

  2. CHARACTERISTICS OF THE AFTERSHOCK SEQUENCE OF THE BORAH PEAK, IDAHO, EARTHQUAKE DETERMINED FROM DIGITAL RECORDINGS OF THE EVENTS.

    USGS Publications Warehouse

    Boatwright, John

    1985-01-01

    The U. S. Geological Survey, Menlo Park, deployed and maintained a network of twelve digital instruments over the 2 weeks following the October 28, 1983, Borah Peak, Idaho, earthquake. The network recorded 45 events with M greater than equivalent to 3. 0, and 6 events with M less than equivalent to 4. 0. The seismic moments of the aftershocks increase with increasing hypocentral depth below 12 km. The dynamic stress drops of the events do not show any systematic variation with depth, however. Most of the events with large stress drops are clustered in the northwest limb of the aftershock distribution; the average stress drop of the southern events is 31 plus or minus 16 bars, while the average stress drop of the events in the northwest limb is 77 plus or minus 52 bars. This clustering of events with large stress drops marks an apparent stress concentration, possibly associated with the arrest of the main shock rupture propagation by a fracture barrier at depth.

  3. Holocene climatic events recorded in palaeoflood slackwater deposits along the middle Yiluohe River valley, middle Yellow River basin, China

    NASA Astrophysics Data System (ADS)

    Zhao, Xueru; Huang, Chun Chang; Pang, Jiangli; Zha, Xiaochun; Guo, Yongqiang; Hu, Guiming

    2016-06-01

    Palaeohydrological investigations were carried out in the middle reaches of the Yiluohe River, a major tributary in the lower-middle Yellow River basin. Typical palaeoflood slackwater deposits (SWDs) were identified in the Holocene pedostratigraphy on the cliffy river banks. Analytical results, including magnetic susceptibility and grain-size distribution data, indicated that these SWDs were deposited from the suspended sediment load in flood water. These SWDs are different from eolian loess, soils and aeolian sands in the riverbank profile. They recorded several episodes of extraordinary palaeoflood events. In the Longmenxia reaches of the Yihe River valley, these flood events were dated at 3100-3000 a, 1800-1700 a, 770-610 a, and 420-340 a using the optically stimulated luminescence method in combination with the pedostratigraphic correlations. In the Longhutan reaches of the Luohe River valley, the palaeoflood events were dated at 1975-1466 a, i.e., from the Han to Wei dynasties (AD 25-534), during which the capital city on the river banks was flooded many times, as recorded in the literature. These extraordinary flood events are well correlated chronologically with the known Holocene climatic events that occurred in the Northern Hemisphere. Thus, the monsoonal climate was highly variable with both floods and droughts occurring frequently during these episodes. These results are important for understanding the response of river systems in eastern Asia to global changes.

  4. Mergers of Charged Black Holes: Gravitational-wave Events, Short Gamma-Ray Bursts, and Fast Radio Bursts

    NASA Astrophysics Data System (ADS)

    Zhang, Bing

    2016-08-01

    The discoveries of GW150914, GW151226, and LVT151012 suggest that double black hole (BH-BH) mergers are common in the universe. If at least one of the two merging black holes (BHs) carries a certain amount of charge, possibly retained by a rotating magnetosphere, the inspiral of a BH-BH system would drive a global magnetic dipole normal to the orbital plane. The rapidly evolving magnetic moment during the merging process would drive a Poynting flux with an increasing wind power. The magnetospheric activities during the final phase of the merger would make a fast radio burst (FRB) if the BH charge can be as large as a factor of \\hat{q}˜ ({10}-9{--}{10}-8) of the critical charge Q c of the BH. At large radii, dissipation of the Poynting flux energy in the outflow would power a short-duration high-energy transient, which would appear as a detectable short-duration gamma-ray burst (GRB) if the charge can be as large as \\hat{q}˜ ({10}-5{--}{10}-4). The putative short GRB coincident with GW150914 recorded by Fermi GBM may be interpreted with this model. Future joint GW/GRB/FRB searches would lead to a measurement or place a constraint on the charges carried by isolate BHs.

  5. Mergers of Charged Black Holes: Gravitational-wave Events, Short Gamma-Ray Bursts, and Fast Radio Bursts

    NASA Astrophysics Data System (ADS)

    Zhang, Bing

    2016-08-01

    The discoveries of GW150914, GW151226, and LVT151012 suggest that double black hole (BH–BH) mergers are common in the universe. If at least one of the two merging black holes (BHs) carries a certain amount of charge, possibly retained by a rotating magnetosphere, the inspiral of a BH–BH system would drive a global magnetic dipole normal to the orbital plane. The rapidly evolving magnetic moment during the merging process would drive a Poynting flux with an increasing wind power. The magnetospheric activities during the final phase of the merger would make a fast radio burst (FRB) if the BH charge can be as large as a factor of \\hat{q}˜ ({10}-9{--}{10}-8) of the critical charge Q c of the BH. At large radii, dissipation of the Poynting flux energy in the outflow would power a short-duration high-energy transient, which would appear as a detectable short-duration gamma-ray burst (GRB) if the charge can be as large as \\hat{q}˜ ({10}-5{--}{10}-4). The putative short GRB coincident with GW150914 recorded by Fermi GBM may be interpreted with this model. Future joint GW/GRB/FRB searches would lead to a measurement or place a constraint on the charges carried by isolate BHs.

  6. Fast instantaneous oceanic plate velocities recorded by the Cretaceous Laytonville limestone: Paleomagnetic analysis and kinematic implications

    SciTech Connect

    Tarduno, J.A.; McWilliams, M.; Sleep, N. )

    1990-09-10

    New paleomagnetic results from 101-89 Ma Laytonville Limestone of the Franciscan Central Belt melange of northern California confirm a southern hemisphere origin as first proposed by Alvarez et al. (1980). Discovery and study of new Laytonville Limestone outcrops extend the paleomagnetic record and provide a definitive determination of age, stratigraphic polarity, and hemisphere of deposition. Paleontological determinations show that five sections are presently overturned and four are presently right side up, as expected from a random distribution of nine blocks in a melange. The exact accretion time is unknown, but geologically reasonable estimates range between 70 and 50 Ma, leading to averaged estimates of poleward velocity between 30 and 14 cm/yr. The averaged values are obtained by dividing the total paleolatitude shift by the difference between magnetization and estimated accretion ages; they reflect net poleward transport over a long time interval and are minimum estimates because they record only the poleward component of motion. An instantaneous poleward velocity is recorded by the systematic inclination decrease of 160 paleomagnetic samples with respect to decreasing age over the 12 m.y. section. Conservative estimates place this minimum velocity at 15 cm/yr. The subduction of old oceanic crust at the boundary of a relatively small plate is hypothesized as a driving mechanism to explain the measured velocities. Coupled with the minimum instantaneous poleward velocities, this hypothesis suggests that the velocities of subducting plates may vary up to a factor of 5. Similar plate geometries and resultant velocities have probably existed at other times in the past, but their discovery may have been hindered by low preservation potential.

  7. Do hurricanes leave unique sedimentological records in floodplain settings? Connecticut River, Tropical Storm Irene and past flood events

    NASA Astrophysics Data System (ADS)

    Yellen, B.; Woodruff, J. D.; Kratz, L. N.; Fallon, A.

    2012-12-01

    In late August, 2011, Tropical Storm Irene passed directly over the Connecticut River watershed causing several low order streams to swell beyond prior historical maximum discharges. Although resultant discharge on the mainstem Connecticut River only amounted to a one in seven year-sized event, its sediment load far exceeded the historical discharge to sediment concentration relationship. Gravity cores taken in off-channel ponds following the hydrograph peak clearly showed deposition of storm-mobilized grains. Samples collected from floodplain forest locations also showed significant accumulation. In both depositional settings, grainsize, lithology and percent organics of flood event deposition differed dramatically from background sedimentation. Long cores collected from these same settings suggest that similar deposits from historical storms of record from the past three centuries are preserved in the floodplain sediment record.; Landsat 5 true color image collected on September 2, 2011 - two days after Tropical Storm Irene left the region.

  8. An alluvial record of El Niño events from northern coastal Peru

    NASA Astrophysics Data System (ADS)

    Wells, Lisa E.

    1987-12-01

    Overbank flood deposits of northern coastal Peru provide the potential for the development of a late Quaternary chronology of El Niño events. Alluvial deposits from the 1982-1983 El Niño event are the basis for establishing a type El Niño deposit. Sedimentary structures suggesting depositional processes range from sheet flows to debris flows, with sheet flood deposits being the most common. The 1982-1983 deposits are characterized by a 50- to 100-cm- thick basal gravel, overlain by a 10- to 100-cm-thick sand bed, grading into a 1- to 10-cm-thick silty sand bed and capped by a very thin layer of silt or clay. The surface of the deposit commonly displays the original shear flow lines crosscut by postdepositional mud cracks and footprints (human and animal). Stacked sequences of flood deposits are present in Pleistocene and Holocene alluvial fill, suggesting that El Niño type events likely occurred throughout the late Quaternary. A relative chronology of the deposits is developed based on terrace and soil stratigraphy and on the degree of preservation of surficial features. A minimum of 15 El Niño events occurred during the Holocene; a minimum of 21 events occurred during the late Pleistocene. Timing of the Holocene events is bracketed by isochrons derived from the archaeologic stratigraphy. Corrected radiocarbon ages from included detrital wood provide the following absolute dates for El Niño events: 1720 ± 60 A.D., 1460 ± 20 A.D., 1380 ± 140 A.D. (error overlaps with the A.D. 1460 event; these may represent a single event), and 1230 ± 60 B.C.

  9. Multiple impact events recorded in the NWA 7298 H chondrite breccia and the dynamical evolution of an ordinary chondrite asteroid

    NASA Astrophysics Data System (ADS)

    Friedrich, Jon M.; Weisberg, Michael K.; Rivers, Mark L.

    2014-05-01

    The major geologic process that has shaped the asteroids and led to development of their regoliths is impact. Petrofabrics in ordinary chondrites are undoubtedly the result of impact events on their asteroidal parent bodies and the foliation present in a chondrite serves as an enduring record of the magnitude of the most intense compacting event experienced by the material. An overwhelming majority of chondrites have an internally consistent petrofabric contained within the spatial dimensions of the entire rock, including across clasts or different petrographic domains. This indicates that the magnitude of the most recent impact to have affected the assembled chondrite was significant enough to impart a foliation across all lithologies. Information of any previous impacts is largely lost because of the consistent, realigned foliations. We present X-ray microtomography derived 3D petrofabric intensity and orientation data for three lithologies in the NWA 7298 breccia. The internally inconsistent petrofabrics among differing lithologies indicate that the magnitude of the final impact event was smaller than previous ones. This latter case preserves fabric information recorded during previous impacts and allows a more complete interpretation of the impact history of a local region of the asteroidal parent. We used our data to infer the sequence and intensity of distinct impact events affecting the NWA 7298 parent asteroid. We suggest a near-surface impact debris zone on the H chondrite parent asteroid as an origin for NWA 7298. These observations yield new opportunities for investigating and interpreting the dynamic collisional evolution of asteroids.

  10. Moment tensor inversion of explosive long period events recorded on Arenal volcano, Costa Rica, constrained by synthetic tests

    NASA Astrophysics Data System (ADS)

    Davi, R.; O'Brien, G. S.; Lokmer, I.; Bean, C. J.; Lesage, P.; Mora, M. M.

    2010-07-01

    In order to constrain the moment tensor solution of an explosive seismic event recorded on Arenal volcano, Costa Rica, we perform tests using synthetic data. These data are generated using a 3D model including the topography of the volcano and the best estimation of the velocity model available for Arenal. Solutions for (i) the moment tensor components, and (ii) the moment tensor plus single forces, are analyzed. When noisy data and mislocated sources are used in the inversion, spurious single forces are easily generated in the solution for the moment tensor components plus single forces. Forces also appear when the inversion is performed using an explosive event recorded on Arenal in 2005. Synthetic tests indicate that these forces might be spurious. However the mechanism is correctly retrieved by the inversion in both solutions. The ability to recover the explosive mechanism for the 2005 event combined with the interpretative aids from the synthetics tests will enable us to invert for the large variation in events observed on Arenal.

  11. Daily life event segmentation for lifestyle evaluation based on multi-sensor data recorded by a wearable device.

    PubMed

    Li, Zhen; Wei, Zhiqiang; Jia, Wenyan; Sun, Mingui

    2013-01-01

    In order to evaluate people's lifestyle for health maintenance, this paper presents a segmentation method based on multi-sensor data recorded by a wearable computer called eButton. This device is capable of recording more than ten hours of data continuously each day in multimedia forms. Automatic processing of the recorded data is a significant task. We have developed a two-step summarization method to segment large datasets automatically. At the first step, motion sensor signals are utilized to obtain candidate boundaries between different daily activities in the data. Then, visual features are extracted from images to determine final activity boundaries. It was found that some simple signal measures such as the combination of a standard deviation measure of the gyroscope sensor data at the first step and an image HSV histogram feature at the second step produces satisfactory results in automatic daily life event segmentation. This finding was verified by our experimental results. PMID:24110323

  12. Expanding neurochemical investigations with multi-modal recording: simultaneous fast-scan cyclic voltammetry, iontophoresis, and patch clamp measurements.

    PubMed

    Kirkpatrick, D C; McKinney, C J; Manis, P B; Wightman, R M

    2016-08-01

    Multi-modal recording describes the simultaneous collection of information across distinct domains. Compared to isolated measurements, such studies can more easily determine relationships between varieties of phenomena. This is useful for neurochemical investigations which examine cellular activity in response to changes in the local chemical environment. In this study, we demonstrate a method to perform simultaneous patch clamp measurements with fast-scan cyclic voltammetry (FSCV) using optically isolated instrumentation. A model circuit simulating concurrent measurements was used to predict the electrical interference between instruments. No significant impact was anticipated between methods, and predictions were largely confirmed experimentally. One exception was due to capacitive coupling of the FSCV potential waveform into the patch clamp amplifier. However, capacitive transients measured in whole-cell current clamp recordings were well below the level of biological signals, which allowed the activity of cells to be easily determined. Next, the activity of medium spiny neurons (MSNs) was examined in the presence of an FSCV electrode to determine how the exogenous potential impacted nearby cells. The activities of both resting and active MSNs were unaffected by the FSCV waveform. Additionally, application of an iontophoretic current, used to locally deliver drugs and other neurochemicals, did not affect neighboring cells. Finally, MSN activity was monitored during iontophoretic delivery of glutamate, an excitatory neurotransmitter. Membrane depolarization and cell firing were observed concurrently with chemical changes around the cell resulting from delivery. In all, we show how combined electrophysiological and electrochemical measurements can relate information between domains and increase the power of neurochemical investigations.

  13. Decoupling of carbon isotope records between organic matter and carbonate prior to the Toarcian Oceanic Anoxic Event (Early Jurassic)

    NASA Astrophysics Data System (ADS)

    Bodin, Stephane; Kothe, Tim; Krencker, Francois-Nicolas; Suan, Guillaume; Heimhofer, Ulrich; Immenhauser, Adrian

    2014-05-01

    Across the Pliensbachian-Toarcian boundary (P-To, Early Jurassic), ca. 1 Myr before the Toarcian Oceanic Anoxic Event (T-OAE), an initial negative carbon isotope excursion has been documented in western Tethys sedimentary rocks. In carbonate, its amplitude (2-3 permil) is similar to the subsequent excursion recorded at the onset of the T-OAE. Being also associated with a rapid warming event, the significance of this first carbon isotope shift, in terms of paleoenvironmental interpretation and triggering mechanism, remains however elusive. Taking advantage of expanded and rather continuous sections in the High Atlas of Morocco, several high-resolution, paired organic-inorganic carbon isotope records have been obtained across the Upper Pliensbachian - Lower Toarcian interval. At the onset of the T-OAE, an abrupt 1-2 permil negative shift is recorded in both organic and inorganic phases, succeeded by a relatively longer term 1-2 permil negative trend and a final slow return to pre-excursion conditions. In accordance with previous interpretations, this pattern indicates a perturbation of the entire exogenic carbon isotope reservoir at the onset of the T-OAE by the sudden release of isotopically light carbon into the atmosphere. By contrast, there is no negative shift in carbon isotopes for the P-To event recorded in bulk organic matter of Morocco. Given the strong dominance of terrestrial particles in the bulk organic matter fraction, this absence indicates that massive input of 12C-rich carbon into the atmosphere is not likely to have happened during the P-To event. A pronounced (2 permil) and abrupt negative shift in carbon isotope is however recorded in the bulk carbonate phase. We suggest that this decoupling between organic and inorganic phase is due to changes in the nature of the bulk carbonate phase. Indeed, the negative shift occurs at the lithological transition between Pliensbachian-lowermost Toarcian limestone-marl alternations and the Lower Toarcian marl

  14. Adaptive sparse signal processing for discrimination of satellite-based radiofrequency (RF) recordings of lightning events

    NASA Astrophysics Data System (ADS)

    Moody, Daniela I.; Smith, David A.

    2015-05-01

    For over two decades, Los Alamos National Laboratory programs have included an active research effort utilizing satellite observations of terrestrial lightning to learn more about the Earth's RF background. The FORTE satellite provided a rich satellite lightning database, which has been previously used for some event classification, and remains relevant for advancing lightning research. Lightning impulses are dispersed as they travel through the ionosphere, appearing as nonlinear chirps at the receiver on orbit. The data processing challenge arises from the combined complexity of the lightning source model, the propagation medium nonlinearities, and the sensor artifacts. We continue to develop modern event classification capability on the FORTE database using adaptive signal processing combined with compressive sensing techniques. The focus of our work is improved feature extraction using sparse representations in overcomplete analytical dictionaries. We explore two possible techniques for detecting lightning events, and showcase the algorithms on few representative data examples. We present preliminary results of our work and discuss future development.

  15. A re-investigation of the 'double dawn' event recorded in the Bamboo Annals

    NASA Astrophysics Data System (ADS)

    Stephenson, F. R.

    1992-06-01

    An allusion to a 'double dawn' phenomenon in an ancient Chinese chronicle, which has been identified as caused by a sunrise eclipse occurring in 899 BC, is discussed. This event has been regarded as of considerable importance in the investigation of earth's past rotation. It is shown that an eclipse interpretation is implausible, not least because the eclipse in question was only annular.

  16. Toward a record of Central Pacific El Niño events since 1880

    NASA Astrophysics Data System (ADS)

    Pascolini-Campbell, M.; Zanchettin, D.; Bothe, O.; Timmreck, C.; Matei, D.; Jungclaus, J. H.; Graf, H.-F.

    2015-01-01

    We investigate the various methods currently available for distinguishing between the Central Pacific (CP) El Niño (or "El Niño Modoki") and the canonical El Niño by considering nine different methods and five sea surface temperature (SST) datasets from 1880 to 2010. This is aimed to demonstrate the variety which exists between different classification methods as well as to help identify years which can be more confidently classified as CP events. Classifying CP El Niños based on the greatest convergence between methods and between SST datasets provides a more robust identification of these events. Analysis of the SST patterns of the CP years identified demonstrates several misclassifications, stressing the importance of not relying solely on indices. After removal, 14 years which are classified the most consistently as CP events include the following: 1885/1886, 1914/1915, 1940/1941, 1958/1959, 1963/1964, 1968/1969, 1977/1978, 1986/1987, 1990/1991, 1991/1992, 1994/1995, 2002/2003, 2003/2004, and 2004/2005. Our findings also indicate the intermittent appearance of CP events throughout the time period investigated, inciting the role of multidecadal natural climate variability in generating CP El Niños.

  17. Record of the Dansgaard-Oechger events in European eolian deposits.

    NASA Astrophysics Data System (ADS)

    Rousseau, D.; Antoine, P.; Hatte, C.; Moine, O.; Zoeller, L.; Lang, A.; Fuchs, M.; Sima, A.; Gerasimenko, N.; Markovic, S.

    2006-12-01

    Loess deposits are covering a wide part of Northern Europe, an area expanding from the coasts of Brittany to the Russian plain. Since ten years or so, efforts have been concentrated in selecting European loess sequences along a main W-E transect at roughly 49°N of latitude, from Northern France to Ukraine. First it has been demonstrated that the main eolian deposition over Europe occurred during the time interval comprised between 38 and 15 kyrs. Second, the high-resolution study of the sequences indicates the alternation of well- developed soils, embryonic or tundra gley paleosols and loess deposits. The succession of these different units show a particular pattern which is correlated with the DO sequence including Greenland IS 8 to 2, even if other shorter intervals, not labeled as DO events, are expressed in the eolian deposits. This correlation is supported by i) OSL and AMS dates on the organic matter preserved in the loess units, ii) mollusk assemblages variations, iii) δ13C on organic matter preserved in the loess, and iv) grain size analysis. We present here the last results of our investigation showing that the DO events preserved in the European loess sequences correspond to interval of low eolian regime, showing higher moisture than during the deposition of the dust. The duration of the DO events also influence the nature of the associated units (paleosol, tundra gleys or embryonic soils, loess) whereas the Heinrich events in between DO events are intervals of dry and windy conditions expressed by coarser material.

  18. Utilisation of Rb/Sr as proxy for mass wasting events in peat records from the Romanian Carpathians

    NASA Astrophysics Data System (ADS)

    Longman, Jack; Ersek, Vasile; Veres, Daniel; Salzmann, Ulrich

    2016-04-01

    Mass wasting events, including landslides, avalanches and flooding related to heavy rains can have a major impact on the local environment. Due to their association to extreme precipitation and glacial retreat, their occurrence is likely to increase as the climate changes in the future. As such, understanding their causation, and predicting their future impact is of paramount importance. To make such predictions, understanding of the relationship between the climate and the mass-wasting event is key. For this to happen, we must use historical records of mass wasting and climate to tie the two together. As a result, a reliable, quick and easy method for determining these events in the sedimentological record must be developed. The Rb/Sr ratio has been suggested as one indicator of mass wasting events, particularly based on lake sediment research in glaciated terrain. Our work was initially developed upon the behaviour of the two elements during weathering, considering that Rb commonly substitutes for K in mineral lattices and Sr commonly for Ca, due to similar ionic radii. Minerals containing K are much more resistant than Ca-bearing ones, and so there is enrichment in weathering products of Ca, and therefore Sr. As a result, Sr should be enriched in weathered material, resulting in a lowering of the Rb/Sr ratio. This assumption has been proven as reliable in similar research involving aeolian deposits and lake sediments. Here we present the first Holocene record based on this proxy from a peat archive from a raised mountain bog in the Romanian Carpathians, nested at the foot of an avalanche-prone glacial cirque. Our geochemical assessments are based on complete digestion of samples, and analysis via ICP-OES, rather than based only on core scanning. Initial results look promising, with the peat core below the active layer (acrotelm) and above the minerogenically-influenced zone producing strong correlation to the estimates of the minerogenic input over the bog based

  19. Cold surges and dust events: Establishing the link between the East Asian Winter Monsoon and the Chinese loess record

    NASA Astrophysics Data System (ADS)

    Wyrwoll, Karl-Heinz; Wei, Junhong; Lin, Zhaohui; Shao, Yaping; He, Feng

    2016-10-01

    The Chinese loess/palaeosol succession is one of the most comprehensive and intensively studied archives of Neogene and Quaternary global palaeoclimate events. Its stratigraphic details are widely recognised to indicate close links to the history and function of the East Asian Winter Monsoon (EAWM) - one of the most active components of the Earth's climate system. But the formal meteorological links between the EAWM and dust emission, both in the present day and in the past, have not been established and with it, the veracity of the loess record as an indicator of the EAWM questioned. Here we show that present day major dust events over northern China, while largely occurring during spring, are nevertheless 'conditioned' by the strength of the preceding EAWM. We also demonstrate, for the first time, a close link between the occurrence of dust events and the strength of the EAWM. From these findings, linked to global-scale climate model simulations, we conclude that the Chinese loess succession provides a convincing proxy record of the strength of the East Asian Winter Monsoon.

  20. Capacitive ECG recording and beat-to-beat interval estimation after major cardiac event.

    PubMed

    Leicht, Lennart; Skobel, Erik; Mathissen, Marcel; Leonhardt, Steffen; Weyer, Soren; Wartzek, Tobias; Reith, Sebastian; Mohler, Werner; Teichmann, Daniel

    2015-08-01

    Today, heart diseases are the most common cause of death in the U.S.. Due to improved healthcare, more and more patients survive a major cardiac event, e.g. a heart attack. However, participation in everyday activity (e.g. driving a car) can be impaired afterwards. Patients might benefit from heart activity monitoring while driving using a capacitive ECG (cECG). However, it is unknown whether cECG is an appropriate monitoring tool for such patients. In this work, first results from a study including 10 patients having survived at least one major cardiac event are presented. It is shown that cECG can be used to diagnose heart rhythm deviations and estimate beat-to-beat intervals similar to conventional ECG. PMID:26738055

  1. Development of a random access multiphoton microscope for fast three-dimensional functional recording of neuronal activity

    NASA Astrophysics Data System (ADS)

    Reddy, Duemani; Saggau, Peter

    2007-02-01

    Over the past two decades, the dendritic processes of neurons have been shown to possess active and dynamic properties that give them the ability to modulate synaptic integration and shape individual synaptic responses. Effectively studying these properties at multiple locations on a live neuron in highly scattering brain tissue requires an imaging/recording mechanism with high spatiotemporal resolution as well as optical sectioning and random access site selection capabilities. Our lab has made significant steps in developing such a system by combining the spatial resolution and optical sectioning ability of imaging techniques such as confocal and multi-photon microscopy with the temporal resolution and random access capability provided by acousto-optic laser scanning. However, all systems that have been developed to date restrict fast imaging to two-dimensional (2D) scan patterns. This severely limits the extent to which many neurons can be studied since they represent complex three-dimensional (3D) structures. We have previously demonstrated a scheme for fast 3D scanning which utilizes a unique arrangement of multiple acousto-optic deflectors and does not require axial movements of the objective lens. Here we couple this scanning scheme to a modified commercial research microscope and use the combined system to effectively image user-defined sites of interest on fluorescent 3D structures with positioning times that are in the low microsecond range. The resulting random-access scanning mechanism allows for functional imaging of complex 3D cellular structures such as neuronal dendrites at frames rates on the order of tens of kilohertz.

  2. Seawater osmium isotope evidence for a middle Miocene flood basalt event in ferromanganese crust records

    USGS Publications Warehouse

    Klemm, V.; Frank, M.; Levasseur, S.; Halliday, A.N.; Hein, J.R.

    2008-01-01

    Three ferromanganese crusts from the northeast, northwest and central Atlantic were re-dated using osmium (Os) isotope stratigraphy and yield ages from middle Miocene to the present. The three Os isotope records do not show evidence for growth hiatuses. The reconstructed Os isotope-based growth rates for the sections older than 10??Ma are higher than those determined previously by the combined beryllium isotope (10Be/9Be) and cobalt (Co) constant-flux methods, which results in a decrease in the maximum age of each crust. This re-dating does not lead to significant changes to the interpretation of previously determined radiogenic isotope neodymium, lead (Nd, Pb) time series because the variability of these isotopes was very small in the records of the three crusts prior to 10??Ma. The Os isotope record of the central Atlantic crust shows a pronounced minimum during the middle Miocene between 15 and 12??Ma, similar to a minimum previously observed in two ferromanganese crusts from the central Pacific. For the other two Atlantic crusts, the Os isotope records and their calibration to the global seawater curve for the middle Miocene are either more uncertain or too short and thus do not allow for a reliable identification of an isotopic minimum. Similar to pronounced minima reported previously for the Cretaceous/Tertiary and Eocene/Oligocene boundaries, possible interpretations for the newly identified middle Miocene Os isotope minimum include changes in weathering intensity and/or a meteorite impact coinciding with the formation of the No??rdlinger Ries Crater. It is suggested that the eruption and weathering of the Columbia River flood basalts provided a significant amount of the unradiogenic Os required to produce the middle Miocene minimum. ?? 2008 Elsevier B.V.

  3. NEV2lkit: a new open source tool for handling neuronal event files from multi-electrode recordings.

    PubMed

    Bongard, Markus; Micol, Daniel; Fernández, Eduardo

    2014-06-01

    The analysis and discrimination of action potentials, or "spikes", is a central issue to systems neuroscience research. Here we introduce a free open source software for the analysis and discrimination of neural spikes based on principal component analysis and different clustering algorithms. The main objective is to supply a friendly user interface that links the experimental data to a basic set of routines for analysis, visualization and classification of spikes in a consistent framework. The tool has been tested on artificial data sets, on multi-electrode extracellular recordings from ganglion cell populations in isolated superfused mouse, rabbit and turtle retinas, and on electrophysiological recordings from mouse visual cortex. Our results show that NEV2lkit is very reliable and able to satisfy the experimental demands in terms of accuracy, efficiency and consistency across experiments. It performs fast unit sorting in single or multiple experiments and allows the extraction of spikes from over large time intervals in continuously recorded data streams. The tool is implemented in C++ and runs cross-platform on Linux, OS X and Windows systems. To facilitate the adaptation and extension as well as the addition of new routines, tools and algorithms for data analysis, the source code, binary distributions for different operating systems and documentation are all freely available at http://nev2lkit.sourceforge.net . PMID:24694167

  4. NEV2lkit: a new open source tool for handling neuronal event files from multi-electrode recordings.

    PubMed

    Bongard, Markus; Micol, Daniel; Fernández, Eduardo

    2014-06-01

    The analysis and discrimination of action potentials, or "spikes", is a central issue to systems neuroscience research. Here we introduce a free open source software for the analysis and discrimination of neural spikes based on principal component analysis and different clustering algorithms. The main objective is to supply a friendly user interface that links the experimental data to a basic set of routines for analysis, visualization and classification of spikes in a consistent framework. The tool has been tested on artificial data sets, on multi-electrode extracellular recordings from ganglion cell populations in isolated superfused mouse, rabbit and turtle retinas, and on electrophysiological recordings from mouse visual cortex. Our results show that NEV2lkit is very reliable and able to satisfy the experimental demands in terms of accuracy, efficiency and consistency across experiments. It performs fast unit sorting in single or multiple experiments and allows the extraction of spikes from over large time intervals in continuously recorded data streams. The tool is implemented in C++ and runs cross-platform on Linux, OS X and Windows systems. To facilitate the adaptation and extension as well as the addition of new routines, tools and algorithms for data analysis, the source code, binary distributions for different operating systems and documentation are all freely available at http://nev2lkit.sourceforge.net .

  5. Warm Events At Summit, Greenland During 2012 Relative To An Evolving Climate Record

    NASA Astrophysics Data System (ADS)

    Shuman, C. A.; Schnaubelt, M. J.; Mefford, T. K.

    2012-12-01

    An evolving temperature record from the Greenland Summit Station, at approximately 3216 m in elevation, has documented unusual periods of near and above freezing air temperatures in July 2012. Since August 2005, data has been collected from well-calibrated and actively-ventilated temperature sensors at a NOAA-ESRL climate observatory. Comparison of these data from a nominal 2 m height above the ice sheet surface over the past seven summers reveals several periods of unusual warmth at the highest elevations of the ice sheet in 2012. Detailed analysis of the available data indicates that temperatures rose to or above freezing for almost 6.5 hours on July 11 at Summit Station. A maximum air temperature of 1 degree C was recorded repeatedly in the 1-minute averages during this period. NOAA's data also indicated brief periods at or above zero on July 12th and 29th as well. These anomalously warm air-temperature periods can now be compared and contrasted with equivalent-quality data from earlier records (automatic weather stations began operating in May 1987 during the GISP2 project) and used to calibrate indications of warm surface temperatures derived from multi-decadal satellite passive microwave and infrared sensors.

  6. The lacustrine record of the Dan-C2 hyperthermal event of the Boltysh Impact Crater, Ukraine

    NASA Astrophysics Data System (ADS)

    Ebinghaus, Alena; Jolley, David W.

    2015-04-01

    Vegetation response to rapid climate change in the geological record is a fundamental element in our understanding of ancient environments; however, the relationships between climate change, plant ecosystems and geological processes are still not fully understood. The filling of the K/Pg Boltysh meteorite crater, Ukraine, comprise a complete terrestrial sedimentological, palynological and δ13C record of the negative carbon isotope excursion of the early Danian hyperthermal episode. The meteorite impact formed a crater of c. 24 km in diameter at c. 65.2 Ma, which was filled with more than 500 m of organic- and fossil-rich claystones, siltstones and marls, interbedded with sandstones and less frequently gravelly sandstones. The sedimentary succession indicates a deep lake setting that was characterised by fluvial input of reworked basement material via a marginal delta system. Palynological investigations indicate a post-impact early- to mid-successional flora followed by a barren zone which coincides with the age of the Chicxulub impact and therefore argues for a series of impact events at the K/Pg boundary. This barren zone was succeeded by a fern spike marking an initial plant re-colonization. The following palynoflora suggests moisture availability oscillations (MAOs) reflecting 41 k.y. obliquity cycles, which can be correlated with lithological fluctuations during lake evolution. The aim is to conduct a detailed, complete facies analysis, and to correlate lake evolutionary aspects with climatic oscillations and vegetation change within the catchment area. This study will be compared with records of similar hyperthermal events, such as the Paleocene-Eocene Thermal Maximum (PETM) in the Western Interior in North America. This integrated approach will help to better understand the controlling factors of global warming events, and their effects on ancient sedimentary environments and ecosystems.

  7. First record of single event upset on the ground, Cray-1 computer memory at Los Alamos in 1976

    SciTech Connect

    Michalak, Sarah E; Quinn, Heather M; Grider, Gary A; Iwanchuk, Paul N; Morrison, John F; Wender, Stephen A; Normand, Eugene; Wert, Jerry L; Johnson, Steve

    2010-01-01

    Records of bit flips in the Cray-1 computer installed at Los Alamos in 1976 lead to an upset rate in the Cray-1 's bipolar SRAMs that correlates with the SEUs being induced by the atmospheric neutrons. In 1976 the Cray Research Company delivered its first supercomputer, the Cray-1, installing it at Los Alamos National Laboratory. Los Alamos had competed with the Lawrence Livermore National Laboratory for the Cray-1 and won, reaching an agreement with Seymour Cray to install the machine for a period of six months for free, after which they could decide whether to buy, lease or return it. As a result, Los Alamos personnel kept track of the computer reliability and performance and so we know that during those six months of operation, 152 memory parity errors were recorded. The computer memory consisted of approximately 70,000 1Kx1 bipolar ECL static RAMs, the Fairchild 10415. What the Los Alamos engineers didn't know is that those bit flips were the result of single event upsets (SEUs) caused by the atmospheric neutrons. Thus, these 152 bit flips were the first recorded SEUs on the earth, and were observed 2 years before the SEUs in the Intel DRAMs that had been found by May and Woods in 1978. The upsets in the DRAMs were shown to have been caused by alpha particles from the chip packaging material. In this paper we will demonstrate that the Cray-1 bit flips, which were found through the use of parity bits in the Cray-1, were likely due to atmospheric neutrons. This paper will follow the same approach as that of the very first paper to demonstrate single event effects, which occurred in satellite flip-flop circuits in 1975. The main difference is that in the four events that occurred over the course of 17 satellite years of operation were shown to be due to single event effects just a few years after those satellite anomalies were recorded. In the case of the Cray-1 bit flips, there has been a delay of more than 30 years between the occurrence of the bit flips and the

  8. Development of a Method to Compensate for Signal Quality Variations in Repeated Auditory Event-Related Potential Recordings

    PubMed Central

    Paukkunen, Antti K. O.; Leminen, Miika M.; Sepponen, Raimo

    2010-01-01

    Reliable measurements are mandatory in clinically relevant auditory event-related potential (AERP)-based tools and applications. The comparability of the results gets worse as a result of variations in the remaining measurement error. A potential method is studied that allows optimization of the length of the recording session according to the concurrent quality of the recorded data. In this way, the sufficiency of the trials can be better guaranteed, which enables control of the remaining measurement error. The suggested method is based on monitoring the signal-to-noise ratio (SNR) and remaining measurement error which are compared to predefined threshold values. The SNR test is well defined, but the criterion for the measurement error test still requires further empirical testing in practice. According to the results, the reproducibility of average AERPs in repeated experiments is improved in comparison to a case where the number of recorded trials is constant. The test-retest reliability is not significantly changed on average but the between-subject variation in the value is reduced by 33–35%. The optimization of the number of trials also prevents excessive recordings which might be of practical interest especially in the clinical context. The efficiency of the method may be further increased by implementing online tools that improve data consistency. PMID:20407635

  9. An optical age chronology of late Quaternary extreme fluvial events recorded in Ugandan dambo soils

    USGS Publications Warehouse

    Mahan, S.A.; Brown, D.J.

    2007-01-01

    There is little geochonological data on sedimentation in dambos (seasonally saturated, channel-less valley floors) found throughout Central and Southern Africa. Radiocarbon dating is problematic for dambos due to (i) oxidation of organic materials during dry seasons; and (ii) the potential for contemporary biological contamination of near-surface sediments. However, for luminescence dating the equatorial site and semi-arid climate facilitate grain bleaching, while the gentle terrain ensures shallow water columns, low turbidity, and relatively long surface exposures for transported grains prior to deposition and burial. For this study, we focused on dating sandy strata (indicative of high-energy fluvial events) at various positions and depths within a second-order dambo in central Uganda. Blue-light quartz optically stimulated luminescences (OSL) ages were compared with infrared stimulated luminescence (IRSL) and thermoluminescence (TL) ages from finer grains in the same sample. A total of 8 samples were dated, with 6 intervals obtained at ???35, 33, 16, 10.4, 8.4, and 5.9 ka. In general, luminescence ages were stratigraphically, geomorphically and ordinally consistent and most blue-light OSL ages could be correlated with well-dated climatic events registered either in Greenland ice cores or Lake Victoria sediments. Based upon OSL age correlations, we theorize that extreme fluvial dambo events occur primarily during relatively wet periods, often preceding humid-to-arid transitions. The optical ages reported in this study provide the first detailed chronology of dambo sedimentation, and we anticipate that further dambo work could provide a wealth of information on the paleohydrology of Central and Southern Africa. ?? 2006 Elsevier Ltd. All rights reserved.

  10. Late Holocene record of sedimentologic and paleooceanographic events in western Guaymas Basin, Gulf of California

    NASA Astrophysics Data System (ADS)

    McGann, M.; Paull, C. K.; Herguera, J. C.; Barron, J. A.; Gwiazda, R.; Anderson, K.; Lundsten, E. M.; Edwards, B. D.; Caress, D. W.

    2015-12-01

    Transects of ≤1.5 m-long vibracores obtained with MBARI's ROV Doc Ricketts reveal late Holocene sedimentologic and paleooceanographic events in western Guaymas Basin, Gulf of California (GOC) (~26.87°N, 111.338°W). Cores were located where layered near-seafloor sediments and subtle bedforms occur in 1793 to 1863 m water depths on the SW flank of the basin using detailed bathymetry and chirp profiles. Color banding was observed in the cores and gamma-density, XRF, grain size, and stable isotope data show that most of the banding is attributed to distal deposition from two turbidities. Distinctive white bands ~4 cm thick are present in three cores dispersed across ~300 m. The white bands are diatom oozes composed primarily of Thalassiothrix longissima as well as lesser abundances of Fragilariopsis doliolus and are probably a result of aggregations of Thalassiothrix-dominated mats that settle through the water column and accumulate on the seafloor. An AMS14C date taken ~3 cm above the white band in one core suggests this event occurred shortly before cal AD 1290±30. The core sites were most likely located beneath an important oceanographic front between nutrient-rich and oligotrophic water masses, probably as the result of well-mixed upper intermediate and surface waters in the mid-GOC and better-stratified tropical waters to the south. This implies the existence of a deeper mixed layer to the N in the mid GOC region most likely controlled by equatorial La Niña events fueled by stronger and more persistent NW winds along the GOC. A substantial reduction in diatom abundance evident by low specimen counts and lack of white bands following this mat-forming event seem to correlate with an abrupt decline in biosiliceous productivity and increases in the abundance of tropical diatoms and silicoflagellates in core MD02-2517 (887 m water depth; western Guaymas Basin slope) at the end of the Medieval Climate Anomaly and transition to the Little Ice Age (~AD 1200-1300).

  11. Expanding neurochemical investigations with multi-modal recording: simultaneous fast-scan cyclic voltammetry, iontophoresis, and patch clamp measurements.

    PubMed

    Kirkpatrick, D C; McKinney, C J; Manis, P B; Wightman, R M

    2016-08-01

    Multi-modal recording describes the simultaneous collection of information across distinct domains. Compared to isolated measurements, such studies can more easily determine relationships between varieties of phenomena. This is useful for neurochemical investigations which examine cellular activity in response to changes in the local chemical environment. In this study, we demonstrate a method to perform simultaneous patch clamp measurements with fast-scan cyclic voltammetry (FSCV) using optically isolated instrumentation. A model circuit simulating concurrent measurements was used to predict the electrical interference between instruments. No significant impact was anticipated between methods, and predictions were largely confirmed experimentally. One exception was due to capacitive coupling of the FSCV potential waveform into the patch clamp amplifier. However, capacitive transients measured in whole-cell current clamp recordings were well below the level of biological signals, which allowed the activity of cells to be easily determined. Next, the activity of medium spiny neurons (MSNs) was examined in the presence of an FSCV electrode to determine how the exogenous potential impacted nearby cells. The activities of both resting and active MSNs were unaffected by the FSCV waveform. Additionally, application of an iontophoretic current, used to locally deliver drugs and other neurochemicals, did not affect neighboring cells. Finally, MSN activity was monitored during iontophoretic delivery of glutamate, an excitatory neurotransmitter. Membrane depolarization and cell firing were observed concurrently with chemical changes around the cell resulting from delivery. In all, we show how combined electrophysiological and electrochemical measurements can relate information between domains and increase the power of neurochemical investigations. PMID:27314130

  12. Apparatus for recording emissions from a rapidly generated plasma from a single plasma producing event

    DOEpatents

    Tan, T.H.; Williams, A.H.

    An optical fiber-coupled detector visible streak camera plasma diagnostic apparatus. Arrays of optical fiber-coupled detectors are placed on the film plane of several types of particle, x-ray and visible spectrometers or directly in the path of the emissions to be measured and the output is imaged by a visible streak camera. Time and spatial dependence of the emission from plasma generated from a single pulse of electromagnetic radiation or from a single particle beam burst can be recorded.

  13. Apparatus for recording emissions from a rapidly generated plasma from a single plasma producing event

    DOEpatents

    Tan, Tai Ho; Williams, Arthur H.

    1985-01-01

    An optical fiber-coupled detector visible streak camera plasma diagnostic apparatus. Arrays of optical fiber-coupled detectors are placed on the film plane of several types of particle, x-ray and visible spectrometers or directly in the path of the emissions to be measured and the output is imaged by a visible streak camera. Time and spatial dependence of the emission from plasmas generated from a single pulse of electromagnetic radiation or from a single particle beam burst can be recorded.

  14. Amazon Paleofires Records: Comparison Between Land Use Change and Palaeoclimatic Events

    NASA Astrophysics Data System (ADS)

    Cordeiro, R. C.; Turcq, B.; Moreira, L. S.; Rodrigues, R. D. A.; Simões Filho, F. L.; Martins, G. S.; Santos, A. B.; Barbosa, M.; da Conceição, M. C. G.; Rodrigues, R. D. C.; Evangelista, H.; Moreira-Turcq, P. F.; Penido, Y. P.; Sifeddine, A.; Seoane, J.

    2014-12-01

    Interpreting the geological record of Amazon biomass combustion requires comparing charcoal accumulation rates in various biomes at different time scales. Charcoal accumulation rates, a proxy for palaeofire records, were obtained in sediment cores from Amazon lakes surrounded by several vegetation types and from a reservoir in an intense land use change region. The records presented in this study were obtained in the following areas i) a reservoir in Alta Floresta region (northern Mato Grosso State); ii) Lago do Saci (southern Pará State), a lake close to Alta Floresta and located at the southern border of Pará State; iii) a bog in an ecotone area in the Humaitá region (southern Amazonas State); iv) lakes in lateritic iron crust of the Carajás Hills (southeastern Pará State); v) Lago Comprido, a floodplain lake close to the Amazon River and surrounded by tropical rain forest (Monte Alegre, Pará State; vi) Lagoa da Pata in the Morro dos Seis Lagos alkaline complex (São Gabriel da Cachoeira, Amazonas State) and vii) Lago Caracaranã, a secluded lake in the northern Amazon cerrado (Roraima State). The highest charcoal accumulation rates were observed for modern records related to an intense change in land use at Alta Floresta, which had no precedent during the Holocene history of the Amazon. High charcoal accumulation rates that were observed in the Carajás region during low lake level phases in the Amazon in the mid-Holocene were comparable to those at the onset of the human settlement in Alta Floresta region. An increase in charcoal accumulation rate was observed in the late Holocene when the lake level was high, suggesting an interaction between climates and human presence. Low charcoal accumulation rates are typical of modern high rainfall environments, as observed in Lagoa da Pata where the environment is not susceptible to occurrences of wildfires even during relatively drier climatic phases. Low charcoal accumulation rates also exist in the relatively

  15. JPL, NASA and the Historical Record: Key Events/Documents in Lunar and Mars Exploration

    NASA Technical Reports Server (NTRS)

    Hooks, Michael Q.

    1999-01-01

    This document represents a presentation about the Jet Propulsion Laboratory (JPL) historical archives in the area of Lunar and Martian Exploration. The JPL archives documents the history of JPL's flight projects, research and development activities and administrative operations. The archives are in a variety of format. The presentation reviews the information available through the JPL archives web site, information available through the Regional Planetary Image Facility web site, and the information on past missions available through the web sites. The presentation also reviews the NASA historical resources at the NASA History Office and the National Archives and Records Administration.

  16. Iridium abundance measurements across bio-event horizons in the fossil record

    SciTech Connect

    Orth, C.J.; Attrep, M. Jr.; Quintana, L.R. )

    1989-01-01

    Geochemical measurements have been performed on thousands of rock samples collected across bio-event horizons using Instrumental Neutron Activation Analysis (INAA) for about 40 common and trace elements and radiochemical isolation procedures for Ir. On selected samples, Os, Pt and Au were also radiochemically determined. These studies have encompassed the time interval from the Precambrian-Cambrian transition to the Late Eocene impact (microspherule) horizons. Our early work strengthened the Alvarez impact hypothesis by finding the Ir (PGE) anomaly at the K-T boundary in continental sedimentary sequences. In collaborations with paleontologists, weak to moderately string Ir anomalies have been discovered at the Frasnian-Famennian boundary in Australia, in the Early Mississippian of Oklahoma, at the Mississipian-Pennsylvanian boundary of Oklahoma and Texas, and in the Late Cenomanian throughout the western interior of North America and on the south coast of England to date. We have found no compelling evidence for an impact related cause for these anomalies although PGE impact signatures in the two Late Cenomanian anomalies could be masked by the strong terrestrial mafic to ultramafic overprint. Thus far, our evidence for extinction events older than the terminal Cretaceous does not support recent hypotheses which suggest that impacts from cyclic swarms of comets in the inner Solar system were responsible for the periodic mass extinctions. 50 refs., 7 figs., 3 tabs.

  17. Constraints on early events in Martian history as derived from the cratering record

    SciTech Connect

    Barlow, N.G. )

    1990-08-30

    The shapes and densities of crater size-frequency distribution curves are used to constrain two major events early in Martian history: termination of high obliteration rates and viability of the multiple impact origin of the crustal dichotomy. Distribution curves of fresh craters superposed on uplands, intercrater plains, and ridged plains display shapes and densities indicative of formation prior to the end of heavy bombardment. This observation correlates with other geologic evidence, suggesting a major change in the erosional regime following the last major basin size impact (i.e., Argrye). In addition, the multisloped nature of the curves supports the idea that the downturn in the crater size-frequency distribution curves reflects the size-frequency distribution of the impactors rather than being the result of erosion. The crustal dichotomy formed prior to the heavy bombardment intermediate epoch based on distribution curves of knobby terrain; if the dichotomy resulted from a single gigantic impact, this observation places constraints on when this event happened. An alternate theory for dichotomy formation, the multiple-impact basin idea, is questioned: since distribution curves of large basins as well as heavy bombardment era units are not represented by a {minus}3 differential power law function, this study finds fewer basins missing on Mars compare to the Moon and Mercury than previously reported. The area covered by these missing basins is less than that covered the northern plains.

  18. Record of palaeoenvironmental changes in the Mid-Polish Basin during the Valanginian Event

    NASA Astrophysics Data System (ADS)

    Morales, Chloé; Kujau, Ariane; Heimhofer, Ulrich; Mutterlose, Joerg; Spangenberg, Jorge; Adatte, Thierry; Ploch, Isabela; Föllmi, Karl B.

    2013-04-01

    The Valanginian stage displays the first major perturbation of the carbon cycle of the Cretaceous period. The Valanginian Weissert episode is associated with a positive excursion (CIE) in δ13Ccarb and δ13Corg values, and the occurrence of a crisis in pelagic and neritic carbonate production (Weissert et al., 1998; Erba, 2004, Föllmi et al., 2007). As for Cretaceous oceanic anoxic events (OAEs), the carbon anomaly is explained by the intensification of continental biogeochemical weathering triggering an increase in marine primary productivity and organic-matter preservation. However, to the contrary of OAEs, the organic matter trapped in the Tethyan Ocean during the Valanginian is both marine and continental and the occurrence of a widespread anoxia could not be evidenced (Westermann et al., 2010; Kujau et al., 2012). The resulting marine Corg burial rates were probably not sufficient to explain the shift in δ13C values and an alternative scheme has been proposed by Westermann et al. (2010): the carbonate platform crisis combined with the storage of organic-matter on the continent may be the major triggers of the δ13C positive shift. (Westermann et al., 2010). We present the results of an analysis of the Wawal drilling core (Mid-Polish Trough), which is of particular interest because of its near-coastal setting and its exceptional preservation, demonstrated by the presence of up to 17 wt.% aragonite. The section consists in marine silty to sandy clays deposited on top of a lower Berriasian karstified limestone. It covers the Early and early Late Valanginian, and displays the onset of the positive excursion. The lack of anoxia is evidenced by trace-element and Rock-Eval data. Two intervals of phosphogenesis are emphasised that appear equivalent in time to the condensed horizons of the northern Tethyan region (Helvetic Alps). A rapid climate change toward less humid and seasonally-contrasted conditions that is similar to the northern Tethyan areas is observed

  19. A late Holocene record of arid events from the Cuzco region, Peru

    NASA Astrophysics Data System (ADS)

    Chepstow-Lusty, Alex; Frogley, Michael R.; Bauer, Brian S.; Bush, Mark. B.; Tupayachi Herrera, Alfredo

    2003-09-01

    The small recently infilled lake basin of Marcacocha (13°13S, 72°12W, 3355 m) in the Cuzco region of Peru has a morphology and location that renders it extremely sensitive to environmental change. A record of vegetation, human impact and climatic change during the past 4200 yr has been obtained from a highly organic core taken from the centre of the basin. Sustained arid episodes that affected the Peruvian Andes may be detectable using the proxy indicator of sedge (Cyperaceae) pollen abundances. As the lake-level was lowered during sustained drier conditions, the local catchment was colonised by Cyperaceae, whereas during lake floods, they retreated or were submerged and pollen production was correspondingly reduced. Drier episodes during prehistoric times occurred around 900 bc, 500 bc, ad 100 and ad 550, with a longer dry episode occurring from ad 900 to 1800. Evidence from the independently derived Quelccaya ice-core record and the archaeological chronology for the Cuzco region appears to support the climatic inferences derived from the sedge data. Many of these aridity episodes appear to correspond with important cultural changes in the Cuzco region and elsewhere in the Central Andes. Copyright

  20. Impulse radio ultra wideband wireless transmission of dopamine concentration levels recorded by fast-scan cyclic voltammetry.

    PubMed

    Ebrazeh, Ali; Bozorgzadeh, Bardia; Mohseni, Pedram

    2015-01-01

    This paper demonstrates the feasibility of utilizing impulse radio ultra wideband (IR-UWB) signaling technique for reliable, wireless transmission of dopamine concentration levels recorded by fast-scan cyclic voltammetry (FSCV) at a carbon-fiber microelectrode (CFM) to address the problem of elevated data rates in high-channel-count neurochemical monitoring. Utilizing an FSCV-sensing chip fabricated in AMS 0.35μm 2P/4M CMOS, a 3-5-GHz, IR-UWB transceiver (TRX) chip fabricated in TSMC 90nm 1P/9M RF CMOS, and two off-chip, miniature, UWB antennae, wireless transfer of pseudo-random binary sequence (PRBS) data at 50Mbps over a distance of <;1m is first shown with bit-error rates (BER) <; 10(-3). Further, IR-UWB wireless transmission of dopamine concentration levels prerecorded with FSCV at a CFM during flow injection analysis (FIA) is also demonstrated with transmitter (TX) power dissipation of only ~4.4μW from 1.2V, representing two orders of magnitude reduction in TX power consumption compared to that of a conventional frequency-shift-keyed (FSK) link operating at ~433MHz. PMID:26737929

  1. Cu isotopes in marine black shales record the Great Oxidation Event

    PubMed Central

    Rodríguez, Nathalie P.; Partin, Camille A.; Andersson, Per; Weiss, Dominik J.; El Albani, Abderrazak; Rodushkin, Ilia; Konhauser, Kurt O.

    2016-01-01

    The oxygenation of the atmosphere ∼2.45–2.32 billion years ago (Ga) is one of the most significant geological events to have affected Earth’s redox history. Our understanding of the timing and processes surrounding this key transition is largely dependent on the development of redox-sensitive proxies, many of which remain unexplored. Here we report a shift from negative to positive copper isotopic compositions (δ65CuERM-AE633) in organic carbon-rich shales spanning the period 2.66–2.08 Ga. We suggest that, before 2.3 Ga, a muted oxidative supply of weathering-derived copper enriched in 65Cu, along with the preferential removal of 65Cu by iron oxides, left seawater and marine biomass depleted in 65Cu but enriched in 63Cu. As banded iron formation deposition waned and continentally sourced Cu became more important, biomass sampled a dissolved Cu reservoir that was progressively less fractionated relative to the continental pool. This evolution toward heavy δ65Cu values coincides with a shift to negative sedimentary δ56Fe values and increased marine sulfate after the Great Oxidation Event (GOE), and is traceable through Phanerozoic shales to modern marine settings, where marine dissolved and sedimentary δ65Cu values are universally positive. Our finding of an important shift in sedimentary Cu isotope compositions across the GOE provides new insights into the Precambrian marine cycling of this critical micronutrient, and demonstrates the proxy potential for sedimentary Cu isotope compositions in the study of biogeochemical cycles and oceanic redox balance in the past. PMID:27091980

  2. Cu isotopes in marine black shales record the Great Oxidation Event.

    PubMed

    Chi Fru, Ernest; Rodríguez, Nathalie P; Partin, Camille A; Lalonde, Stefan V; Andersson, Per; Weiss, Dominik J; El Albani, Abderrazak; Rodushkin, Ilia; Konhauser, Kurt O

    2016-05-01

    The oxygenation of the atmosphere ∼2.45-2.32 billion years ago (Ga) is one of the most significant geological events to have affected Earth's redox history. Our understanding of the timing and processes surrounding this key transition is largely dependent on the development of redox-sensitive proxies, many of which remain unexplored. Here we report a shift from negative to positive copper isotopic compositions (δ(65)CuERM-AE633) in organic carbon-rich shales spanning the period 2.66-2.08 Ga. We suggest that, before 2.3 Ga, a muted oxidative supply of weathering-derived copper enriched in (65)Cu, along with the preferential removal of (65)Cu by iron oxides, left seawater and marine biomass depleted in (65)Cu but enriched in (63)Cu. As banded iron formation deposition waned and continentally sourced Cu became more important, biomass sampled a dissolved Cu reservoir that was progressively less fractionated relative to the continental pool. This evolution toward heavy δ(65)Cu values coincides with a shift to negative sedimentary δ(56)Fe values and increased marine sulfate after the Great Oxidation Event (GOE), and is traceable through Phanerozoic shales to modern marine settings, where marine dissolved and sedimentary δ(65)Cu values are universally positive. Our finding of an important shift in sedimentary Cu isotope compositions across the GOE provides new insights into the Precambrian marine cycling of this critical micronutrient, and demonstrates the proxy potential for sedimentary Cu isotope compositions in the study of biogeochemical cycles and oceanic redox balance in the past.

  3. Cu isotopes in marine black shales record the Great Oxidation Event.

    PubMed

    Chi Fru, Ernest; Rodríguez, Nathalie P; Partin, Camille A; Lalonde, Stefan V; Andersson, Per; Weiss, Dominik J; El Albani, Abderrazak; Rodushkin, Ilia; Konhauser, Kurt O

    2016-05-01

    The oxygenation of the atmosphere ∼2.45-2.32 billion years ago (Ga) is one of the most significant geological events to have affected Earth's redox history. Our understanding of the timing and processes surrounding this key transition is largely dependent on the development of redox-sensitive proxies, many of which remain unexplored. Here we report a shift from negative to positive copper isotopic compositions (δ(65)CuERM-AE633) in organic carbon-rich shales spanning the period 2.66-2.08 Ga. We suggest that, before 2.3 Ga, a muted oxidative supply of weathering-derived copper enriched in (65)Cu, along with the preferential removal of (65)Cu by iron oxides, left seawater and marine biomass depleted in (65)Cu but enriched in (63)Cu. As banded iron formation deposition waned and continentally sourced Cu became more important, biomass sampled a dissolved Cu reservoir that was progressively less fractionated relative to the continental pool. This evolution toward heavy δ(65)Cu values coincides with a shift to negative sedimentary δ(56)Fe values and increased marine sulfate after the Great Oxidation Event (GOE), and is traceable through Phanerozoic shales to modern marine settings, where marine dissolved and sedimentary δ(65)Cu values are universally positive. Our finding of an important shift in sedimentary Cu isotope compositions across the GOE provides new insights into the Precambrian marine cycling of this critical micronutrient, and demonstrates the proxy potential for sedimentary Cu isotope compositions in the study of biogeochemical cycles and oceanic redox balance in the past. PMID:27091980

  4. Cu isotopes in marine black shales record the Great Oxidation Event

    NASA Astrophysics Data System (ADS)

    Fru, Ernest Chi; Rodríguez, Nathalie P.; Partin, Camille A.; Lalonde, Stefan V.; Andersson, Per; Weiss, Dominik J.; El Albani, Abderrazak; Rodushkin, Ilia

    2016-05-01

    The oxygenation of the atmosphere ˜2.45-2.32 billion years ago (Ga) is one of the most significant geological events to have affected Earth's redox history. Our understanding of the timing and processes surrounding this key transition is largely dependent on the development of redox-sensitive proxies, many of which remain unexplored. Here we report a shift from negative to positive copper isotopic compositions (δ65CuERM-AE633) in organic carbon-rich shales spanning the period 2.66-2.08 Ga. We suggest that, before 2.3 Ga, a muted oxidative supply of weathering-derived copper enriched in 65Cu, along with the preferential removal of 65Cu by iron oxides, left seawater and marine biomass depleted in 65Cu but enriched in 63Cu. As banded iron formation deposition waned and continentally sourced Cu became more important, biomass sampled a dissolved Cu reservoir that was progressively less fractionated relative to the continental pool. This evolution toward heavy δ65Cu values coincides with a shift to negative sedimentary δ56Fe values and increased marine sulfate after the Great Oxidation Event (GOE), and is traceable through Phanerozoic shales to modern marine settings, where marine dissolved and sedimentary δ65Cu values are universally positive. Our finding of an important shift in sedimentary Cu isotope compositions across the GOE provides new insights into the Precambrian marine cycling of this critical micronutrient, and demonstrates the proxy potential for sedimentary Cu isotope compositions in the study of biogeochemical cycles and oceanic redox balance in the past.

  5. Assessment of an application for touchscreen devices to record calving-related events in dairy herds and monitor personnel performance.

    PubMed

    Barragan, A A; Workman, J D; Bas, S; Proudfoot, K L; Schuenemann, G M

    2016-07-01

    The objectives of the present study were to assess (1) the effectiveness of a calving training workshop and an application (app) for touchscreen devices to capture calving-related events, and (2) personnel compliance with calving protocols (time from birth to feeding of first colostrum and time that cows spent in labor). Calving personnel (n=23) from 5 large dairy farms (range: 800-10,000 cows) participated in the study. Participants received training through an on-farm workshop regarding calving management practices and functioning of the app before recording calving-related events. Pre- and posttest evaluations were administered to each participant to measure their knowledge gain and satisfaction with the workshop. Calving personnel recorded calving-related events (n=323) using the app for 7 d following training. Furthermore, the records collected with the app were used to assess missing and incorrect data and calving personnel compliance with calving management protocols (recording time that cows spent in labor and timing of feeding first colostrum to calves). Calving personnel reported that the information provided during the training was relevant (agree=14.3% and strongly agree=85.7%) and of great immediate use (agree=33.3% and strongly agree=66.7%). The presented materials and hands-on demonstrations substantially increased the knowledge level of the attendees (by 23.7 percentage points from pre- to posttest scores). The follow-up assessment with participants revealed that the app was easy to use (91.3%) and that they would continue to use it (100%). Frequency of incorrect (r=0.77) or missing (r=0.76) data was positively correlated with calving:personnel ratio. Furthermore, calving personnel compliance with calving protocols was significantly different within and between herds. These results substantiated the great variation in compliance with calving management protocols within and between dairy farms. Furthermore, the app may serve as a tool to monitor

  6. Glacial freshwater discharge events recorded by authigenic neodymium isotopes in sediments from the Mendeleev Ridge, western Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Jang, Kwangchul; Han, Yeongcheol; Huh, Youngsook; Nam, Seung-Il; Stein, Ruediger; Mackensen, Andreas; Matthiessen, Jens

    2013-05-01

    The freshwater budget of the Arctic Ocean is a key component governing the deep water formation in the North Atlantic and the global climate system. We analyzed the isotopic composition of neodymium (ɛNd) in authigenic phases of marine sediments on the Mendeleev Ridge in the western Arctic Ocean spanning an estimated time interval from present to about 75 ka BP. This continuous record was used to reconstruct the ɛNd of the polar deep water (PDW) and changes in freshwater sources to the PDW through time. Three deviations in ɛNd from a long term average of -10.2 were identified at estimated 46-51, 35-39 and 13-21 ka BP. The estimated 46-51 ka BP event can be traced to bursting of ice-dammed lakes accompanying the collapse of the Barents-Kara Ice Sheet, which would have released radiogenic Nd to the eastern Arctic Ocean. The cyclonic surface circulation in the eastern Arctic Ocean must have been stronger than at present for the event to be recorded on the Mendeleev Ridge. For the 35-39 and 13-21 ka BP events, it is likely that the Laurentide Ice Sheet (LIS) supplied the unradiogenic freshwater. The configuration of the anticyclonic circulation in the western Arctic was probably similar to today or expanded eastward. Our simple mass balance calculations suggest that large amounts of freshwater were released but due to significant deep water formation within the Arctic Ocean, the effect on the formation of NADW was probably minor.

  7. In the name of the migrant father—Analysis of surname origins identifies genetic admixture events undetectable from genealogical records

    PubMed Central

    Larmuseau, M H D; Vanoverbeke, J; Gielis, G; Vanderheyden, N; Larmuseau, H F M; Decorte, R

    2012-01-01

    Patrilineal heritable surnames are widely used to select autochthonous participants for studies on small-scale population genetic patterns owing to the unique link between the surname and a genetic marker, the Y-chromosome (Y-chr). Today, the question arises as to whether the surname origin will be informative on top of in-depth genealogical pedigrees. Admixture events that happened in the period after giving heritable surnames but before the start of genealogical records may be informative about the additional value of the surname origin. In this context, an interesting historical event is the demic migration from French-speaking regions in Northern France to the depopulated and Dutch-speaking region Flanders at the end of the sixteenth century. Y-chr subhaplogroups of individuals with a French/Roman surname that could be associated with this migration event were compared with those of a group with autochthonous Flemish surnames. Although these groups could not be differentiated based on in-depth genealogical data, they were significantly genetically different from each other. Moreover, the observed genetic divergence was related to the differences in the distributions of main Y-subhaplogroups between contemporary populations from Northern France and Flanders. Therefore, these results indicate that the surname origin can be an important feature on top of in-depth genealogical results to select autochthonous participants for a regional population genetic study based on Y-chromosomes. PMID:22511074

  8. Extraterrestrial Impact Event Recorded in the Late Triassic Deep-Sea Deposits from Japan

    NASA Astrophysics Data System (ADS)

    Sato, H.; Shirai, N.; Ebihara, M.; Nozaki, T.; Suzuki, K.; Onoue, T.; Kiyokawa, S.

    2014-12-01

    The Late Triassic is marked by the formation of several large impact structures on the Earth, including the 90-km-diameter Manicouagan crater in Canada (Spray and Kelly, 1998). Anomalously high platinum group element (PGE) concentrations have been reported from the Upper Triassic deep-sea deposits in Japan, which have been interpreted to be derived from an extraterrestrial impact event forming the Manicouagan crater (Onoue et al., 2012; Sato et al., 2013). However, previous studies have not clarified the composition of the projectile. Here we report the PGE element ratios and osmium (Os) isotopic compositions of the Upper Triassic ejecta layers in Japan in order to understand the projectile component. Evidence for the Late Triassic impact event has been discovered in the deep-sea claystone layers at four bedded chert sections in the Japanese accretionary complex. The claystone layers contain microspherules, Ni-rich magnetite grains and high abundance of PGEs (Onoue et al., 2012). Biostratigraphic analysis of radiolarian fossils from the studied sections revealed that the claystone layers occur embedded in the upper middle Norian (Sugiyama, 1997; Onoue et al., 2012). Identification of the projectile is attempted by comparing the isotope and elemental ratios of the ejecta deposit with similar data obtained from meteorites. The Ru/Ir and Pt/Ir ratios of all the claystone samples from the study sites are plotted along the mixing line between chondrites and upper continental crust. Although chondrites cannot be distinguished from iron meteorites by using PGE/Ir ratios, the claystone layers have Cr/Ir ratios between 104-105, indicating that the claystone layers are clearly contaminated by chondritic material. The Os isotope data show an abrupt and marked negative excursion from an initial Os isotope ratio of ~0.477 to unradiogenic values of ~0.126 in a claystone layer within a middle Norian bedded chert, indicating the input of chondrite-derived Os into seawater. The

  9. Sulfur record of rising and falling marine oxygen and sulfate levels during the Lomagundi event.

    PubMed

    Planavsky, Noah J; Bekker, Andrey; Hofmann, Axel; Owens, Jeremy D; Lyons, Timothy W

    2012-11-01

    Carbonates from approximately 2.3-2.1 billion years ago show markedly positive δ(13)C values commonly reaching and sometimes exceeding +10‰. Traditional interpretation of these positive δ(13)C values favors greatly enhanced organic carbon burial on a global scale, although other researchers have invoked widespread methanogenesis within the sediments. To resolve between these competing models and, more generally, among the mechanisms behind Earth's most dramatic carbon isotope event, we obtained coupled stable isotope data for carbonate carbon and carbonate-associated sulfate (CAS). CAS from the Lomagundi interval shows a narrow range of δ(34)S values and concentrations much like those of Phanerozoic and modern marine carbonate rocks. The δ(34)S values are a close match to those of coeval sulfate evaporites and likely reflect seawater composition. These observations are inconsistent with the idea of diagenetic carbonate formation in the methanic zone. Toward the end of the carbon isotope excursion there is an increase in the δ(34)S values of CAS. We propose that these trends in C and S isotope values track the isotopic evolution of seawater sulfate and reflect an increase in pyrite burial and a crash in the marine sulfate reservoir during ocean deoxygenation in the waning stages of the positive carbon isotope excursion.

  10. Sulfur record of rising and falling marine oxygen and sulfate levels during the Lomagundi event.

    PubMed

    Planavsky, Noah J; Bekker, Andrey; Hofmann, Axel; Owens, Jeremy D; Lyons, Timothy W

    2012-11-01

    Carbonates from approximately 2.3-2.1 billion years ago show markedly positive δ(13)C values commonly reaching and sometimes exceeding +10‰. Traditional interpretation of these positive δ(13)C values favors greatly enhanced organic carbon burial on a global scale, although other researchers have invoked widespread methanogenesis within the sediments. To resolve between these competing models and, more generally, among the mechanisms behind Earth's most dramatic carbon isotope event, we obtained coupled stable isotope data for carbonate carbon and carbonate-associated sulfate (CAS). CAS from the Lomagundi interval shows a narrow range of δ(34)S values and concentrations much like those of Phanerozoic and modern marine carbonate rocks. The δ(34)S values are a close match to those of coeval sulfate evaporites and likely reflect seawater composition. These observations are inconsistent with the idea of diagenetic carbonate formation in the methanic zone. Toward the end of the carbon isotope excursion there is an increase in the δ(34)S values of CAS. We propose that these trends in C and S isotope values track the isotopic evolution of seawater sulfate and reflect an increase in pyrite burial and a crash in the marine sulfate reservoir during ocean deoxygenation in the waning stages of the positive carbon isotope excursion. PMID:23090989

  11. Sulfur record of rising and falling marine oxygen and sulfate levels during the Lomagundi event

    PubMed Central

    Planavsky, Noah J.; Bekker, Andrey; Hofmann, Axel; Owens, Jeremy D.; Lyons, Timothy W.

    2012-01-01

    Carbonates from approximately 2.3–2.1 billion years ago show markedly positive δ13C values commonly reaching and sometimes exceeding +10‰. Traditional interpretation of these positive δ13C values favors greatly enhanced organic carbon burial on a global scale, although other researchers have invoked widespread methanogenesis within the sediments. To resolve between these competing models and, more generally, among the mechanisms behind Earth’s most dramatic carbon isotope event, we obtained coupled stable isotope data for carbonate carbon and carbonate-associated sulfate (CAS). CAS from the Lomagundi interval shows a narrow range of δ34S values and concentrations much like those of Phanerozoic and modern marine carbonate rocks. The δ34S values are a close match to those of coeval sulfate evaporites and likely reflect seawater composition. These observations are inconsistent with the idea of diagenetic carbonate formation in the methanic zone. Toward the end of the carbon isotope excursion there is an increase in the δ34S values of CAS. We propose that these trends in C and S isotope values track the isotopic evolution of seawater sulfate and reflect an increase in pyrite burial and a crash in the marine sulfate reservoir during ocean deoxygenation in the waning stages of the positive carbon isotope excursion. PMID:23090989

  12. Late Miocene events in the Mediterranean as recorded by carbonate-evaporite relations

    SciTech Connect

    Rouchy, J.M. ); Martin, J.P.S. )

    1992-07-01

    The Messinian Stage in the Mediterranean region is known mainly because of a major evaporitic event whose causes and global implications are still under discussion. Correlations between basinal evaporite-bearing series and marginal carbonate platforms allow for improvement of the classical depostional models, especially concerning the eustatic control of the environmental changes in the Mediterranean. These changes were controlled by the interplay of aperiodic and periodic factors: (1) tectonics, related to the relative motions of the African and Eurasian plates and resultant linear increase in the basin restriction; (2) sea-level fluctuations that alternately aggravated the restriction or allowed marine replenishment, and (3) climatic fluctuations that controlled the level of the Mediterranean during stages of isolation. The Messinian sedimentary succession reflects a typical sequence of progressive isolation: marine marls {yields} laminites {yields} transitional deposits {yields} evaporites {yields} lacustrine deposits. The first stage of the so-called 'salinity crisis' was characterized by a Mediterranean lowstand that resulted in erosion of former platforms and deposition of the lower evaporites. During the next stage, sea level rose (TB3.3 cycle) high enough to temporarily replenish the basin (cyclic upper evaporites, with development of stromatolite-rich deposits). Finally, the uppermost Messinian freshwater to brackish lacustrine deposits reflect both the cessation of sea-water input (maximum tectonic isolation, low sea level) and freshwater input related to increasing runoff.

  13. Basaltic impact melts in the Apollo collections: How many impacts and which events are recorded?

    NASA Technical Reports Server (NTRS)

    Spudis, Paul D.

    1992-01-01

    Many of the rocks in the Apollo collections from the lunar highlands are impact melt breccias of basaltic bulk composition. They are known by a variety of names including low-K Fra Mauro basalt, VHA basalt, and basaltic impact melts. These rocks have been studied to understand the compositional nature of the lunar crust, to decipher the processes of large body impact, and to comprehend the record of impact bombardment of the Moon. Study of terrestrial craters has led to a model for impact melt generation whereby target lithologies are totally melted during impact. The impact melt makes up a few percent of the total volume of crater material; superheated silicate liquids of the impact melt have extremely low viscosities and mix intimately. This mixing thoroughly homogenizes the melt chemically during the excavation of the crater. Colder, unmelted debris is overridden by the melt sheet as the crater cavity grows. Incorporation of these cold clasts rapidly chills the melt, with zones of greater and lesser amounts of clasts being primarily responsible for modestly differing thermal regimes. The net effect of this process is the production of a suite of rocks that have extreme chemical homogeneity, but wide petrographic diversity. Strict application of this model to the petrogenesis of basaltic impact melts from the Moon has some fairly significant consequences for how we interpret early lunar history. The consequences are briefly discussed.

  14. Late Miocene events in the Mediterranean as recorded by carbonate-evaporice relations

    NASA Astrophysics Data System (ADS)

    Rouchy, Jean-Marie; Saint Martin, Jean-Paul

    1992-07-01

    The Messinian Stage in the Mediterranean region is known mainly because of a major evaporitic event whose causes and global implications are still under discussion. Correlations between basinal evaporite-bearing series and marginal carbonate platforms allow for improvement of the classical depositional models, especially concerning the eustatic control of theenvironmental changes in the Mediterranean. These changes were controlled by the interplay of aperiodic and periodic factors: (1) tectonics, related to the relative motions of the African and Eurasian plates and resultant linear increase in basin restriction; (2) sea- level fluctuations that alternately aggravated the restriction or allowed marine replenishment, and (3) climatic fluctuations that controlled the level of the Mediterranean during stages of isolation. The Messinian sedimentary succession reflects a typical sequence of progressive isolation: marine marls → laminites → transitional deposits → evaporites → lacustrine deposits. The structure of the carbonate platforms shows that during early Messinian time, the sea-level regime changed from a highstand (TB3.2 cycle) that was responsible for widespread extension of the carbonate platforms to the classical "Messinian regression" that induced final isolation of the Mediterranean water body and onset of the so-called "salinity crises." The first stage of the crisis was characterized by a Mediterranean lowstand that resulted in erosion of former platforms and deposition of the lower evaporites. During the next stage, sea level rose (TB3.3 cycle) high enough to temporarily replenish the basin (cyclic upper evaporites, with development of stromatolite-rich deposits). Finally, the uppermost Messinian freshwater to brackish lacustrine deposits reflect both the cessation of sea-water input (maximum tectonic isolation, low sea level) and freshwater input related to increasing runoff.

  15. Incidence validation and relationship analysis of producer-recorded health event data from on-farm computer systems in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The principal objective of this study was to analyze the credibility of health data recorded through on-farm recording systems throughout the US and the relationships between health events on a large scale. Substantial progress has been made in the genetic improvement of production traits while hea...

  16. Geochemical and palynological records for the end-Triassic Mass-Extinction Event in the NE Paris Basin (Luxemburg)

    NASA Astrophysics Data System (ADS)

    Kuhlmann, Natascha; van de Schootbrugge, Bas; Thein, Jean; Fiebig, Jens; Franz, Sven-Oliver; Hanzo, Micheline; Colbach, Robert; Faber, Alain

    2016-04-01

    The End-Triassic mass-extinction event is one of the "big five" mass extinctions in Earth's history. Large scale flood basalt volcanism associated with the break-up of Pangaea, which resulted in the opening of the central Atlantic Ocean, is considered as the leading cause. In addition, an asteroid impact in Rochechouart (France; 201 ± 2 Ma) may have had a local influence on ecosystems and sedimentary settings. The Luxembourg Embayment, in the NE Paris Basin, offers a rare chance to study both effects in a range of settings from deltaic to lagoonal. A multidisciplinary study (sedimentology, geochemistry, palynology) has been carried out on a number of outcrops and cores that span from the Norian to lower Hettangian. Combined geochemical and palynological records from the Boust core drilled in the NE Paris Basin, provide evidence for paleoenvironmental changes associated with the end-Triassic mass-extinction event. The Triassic-Jurassic stratigraphy of the Boust core is well constrained by palynomorphs showing the disappaerance of typical Triassic pollen taxa (e.g. Ricciisporites tuberculates) and the occurrence of the marker species Polypodiisporites polymicroforatus within the uppermost Rhaetian, prior to the Hettangian dominance of Classopollis pollen. The organic carbon stable isotope record (δ13Corg) spanning the Norian to Hettangian, shows a series of prominent negative excursions within the middle Rhaetian, followed by a trend towards more positive values (approx -24 per mille) within the uppermost Rhaetian Argiles de Levallois Member. The lowermost Hettangian is characterized by a major negative excursion, reaching - 30 per mille that occurs in organic-rich sediments. This so-called "main negative excursion" is well-known from other locations, for example from Mariental in Northern Germany and from St Audrie's Bay in England, and Stenlille in Denmark. Based on redox-sensitive trace element records (V, Cr, Ni, Co, Th, U) the lowermost Hettangian in most of

  17. Record of seismotectonic events in siliceous cyanobacterial sediments (Magadi cherts), Lake Magadi, Kenya

    NASA Astrophysics Data System (ADS)

    Behr, H.-J.; Röhricht, C.

    The Quaternary sediments of Lake Magadi in the Kenya Rift include large volumes of chert. Before their lithification, these siliceous sediments underwent very strong deformation, as recorded by diapirism with pillow-chert mounds, extrusion along dykes and fault ramps, horizontal liquefaction slides with brecciation, slumping, as well as petee-, flow- and shear structures. Eugster (1969) considered these structures to have resulted from desiccation of Na-silicate precipitates (magadiite) that were deposited over wide areas and were several metres thick. Magadiite can remain soft over long periods; therefore, these ``Magadi-type cherts'' are called the type examples of inorganic cherts. However, field observations and microbiological studies of the cherts show that real inorganic cherts are rare at the type locality of Magadi-type cherts. Most of the cherts are older than the High Magadi Beds and developed from flat-topped calcareous bioherms of Pleurocapsa, Gloecocapsa, and other coccoid cyanobacteria, thinly bedded filamentous microbial mats, stromatolites, bacterial slimes, diatoms, Dascladiacea colonies and other organic matter. Silicification occurred from a silicasol via opal-A to opal-C with final recrystallisation to a chert of quartzine composition. The metabolic processes of cyanobacteria controlled the pH and influenced the dissolution-precipitation mechanism. Collapse, liquefaction and extrusion of the pre-lithified siliceous matrix was caused by seismotectonic rift activity, which activated fault scarplets and large-scale dyke systems. It led to liquefaction and other earthquake-induced structures along the fault ramps and on tilted blocks. Concentrated silicasols were generated by the interaction of alkaline waters with volcanic detritus, coupled with biochemical processes. After liquefaction and extrusion, the material solidified by spontaneous crystallisation in an environment that was characterised by highly variable pH and salinity. The Lake Magadi

  18. Complex life histories of fishes revealed through natural information storage devices: case studies of diadromous events as recorded by otoliths

    NASA Astrophysics Data System (ADS)

    Elfman, M.; Limburg, K. E.; Kristiansson, P.; Svedäng, H.; Westin, L.; Wickström, H.; Malmqvist, K.; Pallon, J.

    2000-03-01

    Diadromous fishes - species that move across salinity gradients as part of their life repertoire - form a major part of coastal and inland fisheries. Conventional mark-recapture techniques have long been used to track their movements, but give incomplete information at best. On the other hand, otoliths (ear-stones) of fishes can provide a complete record of major life history events, as reflected both in their microstructure and elemental composition. Strontium, which substitutes for calcium in the aragonite matrix of otoliths, is a powerful tracer of salinity histories in many migratory fishes. We measured Sr and Ca with a nuclear microprobe (PIXE) and show examples (eel, Anguilla anguilla; brown trout, Salmo trutta; American shad, Alosa sapidissima) of how the technique has solved several mysteries within fisheries biology.

  19. Abrupt climatic events during OIS-3 recorded in terrestrial sediments in the Netherlands: a multi-proxy approach

    NASA Astrophysics Data System (ADS)

    Bos, J. A. A.; Bohncke, S. J. P.; Kasse, C.; van Huissteden, J.; Schokker, J.; Bunnik, F. P. M.; Wallinga, J.

    2009-04-01

    Abrupt climatic changes during Oxygen Isotope Stage 3 (OIS-3 or Weichselian Middle Pleniglacial) are revealed in the oxygen isotope records of the Greenland ice cores and in the North Atlantic marine cores. In the Greenland ice cores, these so-called D/O cycles start with a rapid warming of 5-10˚C within a few decades, followed by a phase of gradual cooling over several hundred to more than a thousand years and often end with a final reduction in temperature back to cold, stadial conditions. On the adjacent European continent, however, climatic variability during this time interval is poorly known. High-resolution terrestrial records are scarce and the discontinuous nature of sedimentation and repeated erosion on the continent combined with poor dating control often hampers a detailed study of the vegetation and climate. In this contribution, a Middle Weichselian sequence with shallow lacustrine deposits, intercalated by fluvial sediments with permafrost features, is presented from the Netherlands. Within this Middle Weichselian sequence, rapid warming events are assumed to have given rise to thawlake formation and/or deposition of organic-rich lacustrine sediments, while the extreme cooling events of the D/O cycles are probably represented in the sequences by clastic intervals during which periglacial features developed. In the sixties of the last century, two warming events or "interstadials" were first recognized and described from terrestrial Middle Weichselian sequences from the Hengelo basin in the Netherlands, the Hengelo- and Denekamp interstadials, respectively. The shift from a polar desert to shrub tundra (i.e. Hengelo interstadial) and tundra to shrub tundra (i.e. Denekamp interstadial), visible in the pollen diagrams of this area, was interpreted as a temporary amelioration of the climate and were therefore given the names of interstadials. In time the Hengelo- and Denekamp interstadials were also correlated with D/O cycles 12 respectively 8 in the

  20. Cold event at 8200 yr B.P. recorded in annually laminated lake sediments in eastern Europe

    NASA Astrophysics Data System (ADS)

    Veski, Siim; Seppä, Heikki; Ojala, Antti E. K.

    2004-08-01

    A quantitative annual mean temperature reconstruction from an annually laminated lake-sediment sequence in Estonia, eastern Europe, shows a distinct cold period at 8400 8080 yr B.P. (= before A.D. 2000); the timing is consistent with that seen in the Greenland ice-core data and various high-resolution records from western Europe. During maximal cooling at 8250 8150 yr B.P., the annual mean temperature in Estonia was ˜2.0 °C colder than prior to and ˜3.0 °C colder than after the cooling. The pollen-stratigraphic and sedimentological data suggest especially cold and snowy winter conditions. The duration and amplitude of the cold event agree with the modeled impact of a sudden freshening of the North Atlantic surface water and subsequent perturbation of the thermohaline circulation. Provided that the cold event was caused by a pulse of freshwater—from the melting Laurentide Ice Sheet—to the North Atlantic, the results indicate a strong teleconnection between the North Atlantic oceanic forcing and the east European climate at least up to long 26°E, mediated probably by the changing intensity of the zonal atmospheric circulation.

  1. Environmental Magnetic Record of Worldwide Late Pleistocene Climatic Events from the Pacific Margin of the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Sagnotti, L.; Patrizia, M.; Camerlenghi, A.; Rebesco, M.

    2001-12-01

    We report a high-resolution paleomagnetic and rock magnetic study carried out on three piston cores, recovered within the SEDANO Project in the western continental rise of the Antarctic Peninsula. The cores span the time interval between the present-day and the last interglacial, with one (SED-06) extending to about 150 kyr. An improved age model for the three cores was obtained by correlating the relative paleointensity records to global paleointensity reference curves (SINT-200). In such improved time frame we found that sharp coercivity minima (corresponding to characteristic dark grey layers in the last glacial interval of the SED-02 and SED-04 cores) are time correlated with the Heinrich events identified in the North Atlantic sediments. We relate such environmental magnetic signal to variations in deep sea diagenetic processes of sulphides formation, which reflect changes in the input of detrital organic matter controlled by past sea-ice extent. Because of the inherent chronological uncertainties it is not yet possible to identify time lags or leads in interhemispheric linkage, but the timing of these dark grey layers is close enough to that the Heinrich events to suggest an interhemispheric consistent response to global climate changes during the last glaciation.

  2. Design, development and experimental validation of a non-invasive device for recording respiratory events during bottle feeding.

    PubMed

    Cavaiola, C; Tamilia, E; Massaroni, C; Morbidoni, G; Schena, E; Formica, D; Taffoni, F

    2014-01-01

    In newborns, a poor coordination between sucking, swallowing and breathing may undermine the effectiveness of oral feeding and signal immaturity of Central Nervous System. The aim of this work is to develop and validate a non-invasive device for recording respiratory events of newborns during bottle feeding. The proposed device working principle is based on the convective heat exchanged between two hot bodies and the infants' breathing. The sensing elements are inserted into a duct and the gas exchanged by infants is conveyed into this duct thanks to an ad hoc designed system to be mounted on a commercial feeding bottle. Two sets of experiments have been carried out in order to investigate the discrimination threshold of the device and characterize the sensor response at oscillating flows. The effect of distance and tilt between nostrils and device, and the breathing frequency, have been investigated simulating nostrils and neonatal respiratory pattern. The device has a discrimination threshold lower than 0.5 L/min at both 10° and 20° of tilt. Distance for these two settings does not affect the threshold in the investigated range (10-20 mm). Moreover, the device is able to detect breathing events, and to discriminate the onset of expiratory phase, during a neonatal respiratory task delivered by a lung simulator. The results foster the successful application of this device to the assessment of the temporal breathing pattern of newborns during bottle feeding with a non-invasive approach. PMID:25570404

  3. Variability in recording and scoring of respiratory events during sleep in Europe: a need for uniform standards.

    PubMed

    Arnardottir, Erna S; Verbraecken, Johan; Gonçalves, Marta; Gjerstad, Michaela D; Grote, Ludger; Puertas, Francisco Javier; Mihaicuta, Stefan; McNicholas, Walter T; Parrino, Liborio

    2016-04-01

    Uniform standards for the recording and scoring of respiratory events during sleep are lacking in Europe, although many centres follow the published recommendations of the American Academy of Sleep Medicine. The aim of this study was to assess the practice for the diagnosis of sleep-disordered breathing throughout Europe. A specially developed questionnaire was sent to representatives of the 31 national sleep societies in the Assembly of National Sleep Societies of the European Sleep Research Society, and a total of 29 countries completed the questionnaire. Polysomnography was considered the primary diagnostic method for sleep apnea diagnosis in 10 (34.5%), whereas polygraphy was used primarily in six (20.7%) European countries. In the remaining 13 countries (44.8%), no preferred methodology was used. Fifteen countries (51.7%) had developed some type of national uniform standards, but these standards varied significantly in terms of scoring criteria, device specifications and quality assurance procedures between countries. Only five countries (17.2%) had published these standards. Most respondents supported the development of uniform recording and scoring criteria for Europe, which might be based partly on the existing American Academy of Sleep Medicine rules, but also take into account differences in European practice when compared to North America. This survey highlights the current varying approaches to the assessment of patients with sleep-disordered breathing throughout Europe and supports the need for the development of practice parameters in the assessment of such patients that would be suited to European clinical practice.

  4. Are All Vaccines Created Equal? Using Electronic Health Records to Discover Vaccines Associated With Clinician-Coded Adverse Events

    PubMed Central

    Boland, Mary Regina; Tatonetti, Nicholas P

    2015-01-01

    Adverse drug events (ADEs) are responsible for unnecessary patient deaths making them a major public health issue. Literature estimates 1% of ADEs recorded in Electronic Health Records (EHRs) are reported to federal databases making EHRs a vital source of ADE-related information. Using Columbia University Medical Center (CUMC)’s EHRs, we developed an algorithm to mine for vaccine-related ADEs occurring within 3 months of vaccination. In phase one, we measured the association between vaccinated patients with an ADE (cases) against those vaccinated without an ADE. To adjust for healthcare-process effects, phase two compared cases against those who returned to CUMC within 3 months without an ADE. We report 7 results passing multiplicity correction after demographic confounder adjustment. We observed an association, having some literature support, between swine flu vaccination and ADEs (H1N1v-like, OR=9.469, p<0.001; H1N1/H3N2, OR=3.207, p<0.001). Our algorithm could inform clinicians of the risks/benefits of vaccinations towards improving clinical care. PMID:26306268

  5. Identification of Adverse Drug Events from Free Text Electronic Patient Records and Information in a Large Mental Health Case Register

    PubMed Central

    Jackson, Richard George; Ball, Michael; Ibrahim, Zina M.; Broadbent, Matthew; Dzahini, Olubanke; Stewart, Robert; Johnston, Caroline; Dobson, Richard J. B.

    2015-01-01

    Objectives Electronic healthcare records (EHRs) are a rich source of information, with huge potential for secondary research use. The aim of this study was to develop an application to identify instances of Adverse Drug Events (ADEs) from free text psychiatric EHRs. Methods We used the GATE Natural Language Processing (NLP) software to mine instances of ADEs from free text content within the Clinical Record Interactive Search (CRIS) system, a de-identified psychiatric case register developed at the South London and Maudsley NHS Foundation Trust, UK. The tool was built around a set of four movement disorders (extrapyramidal side effects [EPSEs]) related to antipsychotic therapy and rules were then generalised such that the tool could be applied to additional ADEs. We report the frequencies of recorded EPSEs in patients diagnosed with a Severe Mental Illness (SMI) and then report performance in identifying eight other unrelated ADEs. Results The tool identified EPSEs with >0.85 precision and >0.86 recall during testing. Akathisia was found to be the most prevalent EPSE overall and occurred in the Asian ethnic group with a frequency of 8.13%. The tool performed well when applied to most of the non-EPSEs but least well when applied to rare conditions such as myocarditis, a condition that appears frequently in the text as a side effect warning to patients. Conclusions The developed tool allows us to accurately identify instances of a potential ADE from psychiatric EHRs. As such, we were able to study the prevalence of ADEs within subgroups of patients stratified by SMI diagnosis, gender, age and ethnicity. In addition we demonstrated the generalisability of the application to other ADE types by producing a high precision rate on a non-EPSE related set of ADE containing documents. Availability The application can be found at http://git.brc.iop.kcl.ac.uk/rmallah/dystoniaml. PMID:26273830

  6. A novel method for recording neuronal depolarization with recording at 125-825 Hz: implications for imaging fast neural activity in the brain with electrical impedance tomography.

    PubMed

    Oh, T; Gilad, O; Ghosh, A; Schuettler, M; Holder, D S

    2011-05-01

    Electrical impedance tomography (EIT) is a recently developed medical imaging method which has the potential to produce images of fast neuronal depolarization in the brain. Previous modelling suggested that applied current needed to be below 100 Hz but the signal-to-noise ratio (SNR) recorded with scalp electrodes during evoked responses was too low to permit imaging. A novel method in which contemporaneous evoked potentials are subtracted is presented with current applied at 225 Hz to cerebral cortex during evoked activity; although the signal is smaller than at DC by about 10×, the principal noise from the EEG is reduced by about 1000×, resulting in an improved SNR. It was validated with recording of compound action potentials in crab walking leg nerve where peak changes of -0.2% at 125 and 175 Hz tallied with biophysical modelling. In recording from rat cerebral cortex during somatosensory evoked responses, peak impedance decreases of -0.07 ± 0.006% (mean ± SE) with a SNR of >50 could be recorded at 225 Hz. This method provides a reproducible and artefact free means for recording resistance changes during neuronal activity which could form the basis for imaging fast neural activity in the brain.

  7. Consistently dated records from three Greenland ice cores reveal regional millennial-scale isotope gradients with possible Heinrich Event imprint

    NASA Astrophysics Data System (ADS)

    Seierstad, Inger K.; Rasmussen, Sune O.

    2014-05-01

    We here present records from the NGRIP, GRIP and GISP2 ice cores tied to the same chronology for the past 104 ka at an unprecedented time resolution. The three ice cores have been linked by matching distinct peaks in volcanic proxy records and other impurity records from the three ice cores, assuming that these layers of elevated impurity content represent the same, instantaneous event in the past at all three sites. In total there are more than 900 identified marker horizons between the three cores including previously published match points, of which we introduce a minor revision. Our matching is independently confirmed by new and existing volcanic ash layers (tephra). The depth-depth relationship from the detailed matching is used to transfer the most recent and widely used Greenland ice core chronology, the GICC05modelext timescale, to the two Summit cores, GRIP and GISP2. Furthermore, we provide gas chronologies for the Summit cores that are consistent with the GICC05modelext timescale by utilizing both existing and new unpublished gas data. A comparison of the GICC05modelext and the former GISP2 timescale reveals major discrepancies in short time intervals during the glacial section. We detect a pronounced change in the relative annual layer thickness between the two Summit sites and NGRIP across the Last Glacial termination and early-to-mid Holocene, which can be explained by a relative accumulation increase at NGRIP compared to the Summit region as response to the onset of the Holocene and the climatic optimum. Between stadials and interstadials we infer that the accumulation contrast typically was nearly 10% greater at Summit compared to at NGRIP. The δ18O temperature-proxy records from NGRIP, GRIP and GISP2 are generally very similar and display a synchronous behavior at climate transitions, but the δ18O differences between Summit and NGRIP is slowly changing over the last glacial-interglacial cycle superimposed by abrupt millennial-to centennial scale

  8. Century-scale variability in late-summer rainfall events recorded over seven centuries in subannually laminated lacustrine sediments, White Pass, British Columbia

    NASA Astrophysics Data System (ADS)

    Cockburn, Jaclyn M. H.; Lamoureux, Scott F.

    2007-03-01

    Formation of annually laminated sediments in Summit Lake, White Pass, British Columbia is controlled by runoff generated by snowpack and glacier melt and major rainfall events. The 700-yr varve record is divided into two subannual series (early and late) based on sedimentological criteria and sedimentary structures within each varve. A comparison of recent subannual laminae with nearby meteorological records supports the interpretation they are formed by river discharge events generated by major snow and glacier melt events and large late-summer rainfall events. A significant correlation exists between the late subannual thickness series and the size of the largest rainfall events in late summer. The long record indicates there was an abrupt increase in the thickness and frequency of major rainfall-induced sedimentary events at the end of the seventeenth century. In addition, the frequency of laminae generated by early runoff events also increased. However, early subannual varve thickness component remains statistically the same as the thickness prior to the end of the seventeenth century. This suggests the change in varve thickness at this time is due to increases in major late-summer rainfall frequency rather than increased sediment availability caused by regional Little Ice Age glacier advances.

  9. Fast adaptation of the internal model of gravity for manual interceptions: evidence for event-dependent learning.

    PubMed

    Zago, Myrka; Bosco, Gianfranco; Maffei, Vincenzo; Iosa, Marco; Ivanenko, Yuri P; Lacquaniti, Francesco

    2005-02-01

    We studied how subjects learn to deal with two conflicting sensory environments as a function of the probability of each environment and the temporal distance between repeated events. Subjects were asked to intercept a visual target moving downward on a screen with randomized laws of motion. We compared five protocols that differed in the probability of constant speed (0g) targets and accelerated (1g) targets. Probability ranged from 9 to 100%, and the time interval between consecutive repetitions of the same target ranged from about 1 to 20 min. We found that subjects systematically timed their responses consistent with the assumption of gravity effects, for both 1 and 0g trials. With training, subjects rapidly adapted to 0g targets by shifting the time of motor activation. Surprisingly, the adaptation rate was independent of both the probability of 0g targets and their temporal distance. Very few 0g trials sporadically interspersed as catch trials during immersive practice with 1g trials were sufficient for learning and consolidation in long-term memory, as verified by retesting after 24 h. We argue that the memory store for adapted states of the internal gravity model is triggered by individual events and can be sustained for prolonged periods of time separating sporadic repetitions. This form of event-related learning could depend on multiple-stage memory, with exponential rise and decay in the initial stages followed by a sample-and-hold module. PMID:15456796

  10. Carbon isotope records reveal synchronicity between carbon cycle perturbation and the "Carnian Pluvial Event" in the Tethys realm (Late Triassic)

    NASA Astrophysics Data System (ADS)

    Dal Corso, Jacopo; Gianolla, Piero; Newton, Robert J.; Franceschi, Marco; Roghi, Guido; Caggiati, Marcello; Raucsik, Béla; Budai, Tamás; Haas, János; Preto, Nereo

    2015-04-01

    In the early Late Triassic a period of increased rainfall, named the Carnian Pluvial Event (CPE), is evidenced by major lithological changes in continental and marine successions worldwide. The environmental change seems to be closely associated with a negative carbon isotope excursion that was identified in a stratigraphic succession of the Dolomites (Italy) but the temporal relationship between these phenomena is still not well defined. Here we present organic-carbon isotope data from Carnian deep-water stratigraphic sections in Austria and Hungary, and carbonate petrography of samples from a marginal marine section in Italy. A negative 2-4‰ δ13C shift is recorded by bulk organic matter in the studied sections and is coincident with a similar feature highlighted in higher plant and marine algal biomarker carbon-isotope records from the Dolomites (Italy), thus testifying to a global change in the isotopic composition of the reservoirs of the exchangeable carbon. Our new observations verify that sedimentological changes related to the CPE coincide with the carbon cycle perturbation and therefore occurred synchronously within the western Tethys. Consistent with modern observations, our results show that the injection of 13C-depleted CO2 into the Carnian atmosphere-ocean system may have been directly responsible for the increase in rainfall by intensifying the Pangaean mega-monsoon activity. The consequent increased continental weathering and erosion led to the transfer of large amounts of siliciclastics into the basins that were rapidly filled up, while the increased nutrient flux triggered the local development of anoxia. The new carbonate petrography data show that these changes also coincided with the demise of platform microbial carbonate factories and their replacement with metazoan driven carbonate deposition. This had the effect of considerably decreasing carbonate deposition in shallow water environments.

  11. Possible Pre-Cryogenian Eutrophication Event Recorded In ~770-742 Ma Strata Of The Uinta Mountain Group, Utah, USA

    NASA Astrophysics Data System (ADS)

    Dehler, C. M.; Hayes, D. S.; Nagy, R. M.

    2011-12-01

    Previous mid-Neoproterozoic microfossil diversity studies yield evidence for a relatively sudden biotic change prior to the Cryogenian (Sturtian) glaciations. In an event interpreted as a mass extinction of eukaryotic phytoplankton followed by bacterial dominance, diverse assemblages of complex acritarchs are replaced by more uniform assemblages consisting of simple leiosphaerid acritarchs and bacteria. Recent data from the Chuar Group of the Grand Canyon (770-742 Ma) suggest this biotic change was caused by eutrophication rather than the previous idea that this change was due to the direct effects of Sturtian glaciation. Evidence includes total organic carbon increases indicative of increasing primary productivity followed by iron speciation values that suggest sustained water column anoxia. A new data set (this study) suggests that this same eutrophication event may be recorded in shale units of the formation of Hades Pass and the Red Pine Shale of Utah's Neoproterozoic Uinta Mountain Group (770-742 Ma). Preliminary results of this study include a significant shift in microfossil assemblage from a higher-diversity (H'= 0.60) fauna that includes some ornamented acritarchs to a lower-diversity (H' = 0.11) fauna dominated by smooth leiosphaerids and microfossils of a bacterial origin (Ba|lla/ Sphaerocongregus sp.). This biotic change co-occurs with a significant increase in total organic carbon values that directly follows a positive carbon-isotopic excursion, suggesting increased primary productivity that may have been the result of elevated sediment influx and nutrient availability. Both the biotic change and period of increased total organic carbon values correspond with the onset of an interval of anoxia (indicated by total iron to aluminum ratios above 0.60) and a spike in sulfur concentration. Thus far, these findings support 1) correlations between the Uinta Mountain and Chuar groups, 2) the idea that the biotic turnover preserved in both strata was at least

  12. Flooding of the Great River during the Common Era: A Paleohydrological Record of High Magnitude Flood Events from the Central Mississippi River Valley

    NASA Astrophysics Data System (ADS)

    Williams, J. W.; Munoz, S. E.; Gruley, K. E.; Massie, A.

    2014-12-01

    Streamflow characteristics are known to be sensitive to changes in climate, but few continuous records of flooding exist to evaluate the response of hydrological systems to centennial- and millennia-scale climate changes. Here, we present sedimentary records from two oxbow lakes (Horseshoe Lake and Grassy Lake, Illinois, USA) in the central Mississippi River valley (CMRV) that display abrupt shifts in sediment composition and particle-size consistent with deposition by floodwaters immediately following inundation of the floodplain. The sedimentary record at Horseshoe Lake begins ca. AD 100 and displays five major flood events, with four of these occurring after ca. AD 1100. Situated 200 km downstream, the record from Grassy Lake begins later, ca. AD 800, and also shows four major flood events after ca. AD 1100. An analysis of synchronicity using Bayesian age modelling software shows high likelihoods that the four overlapping flood events occurred at the same time, confirming that these events resulted from flooding of the Mississippi River. The most recent event we record at AD 1840 ± 50 corresponds to the AD 1844 flood, the largest flood by discharge (37 m3/s) measured by the gauging station at St. Louis, Missouri, indicating that our sedimentary records document high magnitude flood events. Together, our two sedimentary records show a major shift in the frequency of high magnitude flooding in the central Mississippi River at ca. AD 1100. From AD 100 - AD 1100, only one relatively subtle flood event is recorded, but from AD 1100 - AD 1900, four high magnitude floods deposited distinctive sediment at both sites. The period of infrequent flooding corresponds to a time of agricultural intensification and population growth in the CMRV, while the entire region was abandoned when flood frequency increased. The pronounced shift in flood frequency we observe in our records at ca. AD 1100 begins during the Medieval Climate Anomaly (MCA; AD 950 - AD 1250), a period of

  13. Investigation of Historic Seismic and Infrasound Records from Events Occurred at the Region of Novaya Zemplya Test Site by the USSR Stations

    NASA Astrophysics Data System (ADS)

    Sokolova, Inna

    2014-05-01

    Located in the north the Novaya Zemlya Test Site was used in Soviet time for conducting unique nuclear weapon tests in different mediums. 130 nuclear explosions with total yield 265 megatons were conducted at the Test Site for the period 1955-1990. During this period the following nuclear explosions were conducted: 1 surface explosion, 85 air explosions, 2 above water explosions, 3 underwater explosions and 39 underground explosions (in boreholes and tunnels). In addition, tectonic earthquakes and induced earthquakes caused by multi-megatons UNE occur near the Test Site. Unfortunately, only few seismic events occurred on the territory of the Test Site were recorded by digital stations. However, the archives of different seismological organizations of the USSR contain huge amount of analogue seismograms recorded by permanent and temporary stations. Historical seismograms of nuclear explosions and earthquakes from Novaya Zemlya Test site territory were digitized by the Complex Seismological Expedition IPE RAS and by the Institute of Geophysical Researches RK; a database of the events from the Test Site containing 470 seismograms at epicentral distance 2100-3800 was created. The database includes seismic records of air, underground nuclear explosions, and records of underwater nuclear explosion conducted within "Korall" exercise. In addition, infrasound records of waves from multi-megatons air nuclear explosions recorded by a microbarograph installed at Talgar seismic station at distance ~3600 km from the Test Site were digitized. Kinematic and dynamic parameters of nuclear explosions records conducted in different mediums (air, under water and underground) were investigated by the digitized records from events at Novaya Zemlya Test Site; specific features of wave pattern for each class of events were found.

  14. Skeletal isotope records of growth perturbations in Porites corals during the 1997-1998 mass bleaching event

    NASA Astrophysics Data System (ADS)

    Suzuki, A.; Gagan, M.; Fabricius, K.; Isdale, P.; Yukino, I.; Kawahata, H.

    2003-04-01

    Severe coral bleaching occurred throughout the tropics in 1997/98. We report skeletal UV fluorescence, oxygen isotope, and carbon isotope evidence for perturbations in coral skeletal growth due to bleaching at Ishigaki Island, Japan, and Pandora Reef, Great Barrier Reef. Bleached corals showed abrupt reductions in skeletal extension rate immediately after summer temperature maxima, indicating that bleaching inhibits coral calcification. A colony growing at the low tide line in Ishigaki exhibited clear blue UV fluorescent bands associated with recurrent growth interruptions. Based on the length of time-gaps observed in the annual isotopic cycle, the typical time required for a coral to recover from bleaching is estimated to be about 5--6 months. The effect of bleaching on the oxygen isotope ratio -- temperature relationship was negligible. However, the Ishigaki corals showed lower carbon isotope ratios during bleaching indicating depressed coral metabolism associated with a reduction in calcification. In contrast, skeletal carbon isotope ratios in the Pandora Reef corals exhibited little change in response to bleaching. This is because the records for Pandora Reef were derived from the shaded sides of coral colonies, where algal photosynthesis was particularly slow prior to bleaching, thus subduing the carbon isotope response to bleaching. Taken together, the isotopic and UV fluorescence signals can be used to reconstruct past bleaching events.

  15. RETRACTED: Extreme oceanographic events recorded in the southwest coast of India during the 1998-1999 summer season

    NASA Astrophysics Data System (ADS)

    Krishna, K. Muni

    2010-01-01

    This article has been removed at the request of the Editor-in-chief and Author. Please see Elsevier Policy on Article Withdrawal ( http://www.elsevier.com/locate/withdrawalpolicy). Reason: This article has been retracted at the request of the Editor-in-Chief and Author as the author has plagiarized part of a paper that had already appeared in another journal, as written by the following authors: Roy, Weeks, Rouault, Nelson, Barlow, Van der Lingen. "Extreme oceanographic events recorded in the Southern Benguela during the 1999-2000 summer season", South African J. Sci., 2001, volume 97 (11-12), pp. 465-471. While the underlying scientific data of Dr Krishna's work may be original, the wording, sentence, and paragraph structure of the entire manuscript shows such strong similarity (in many cases wholesale replication of sentences and phrases) that we must conclude that there has been excessive use of previously published material without appropriate attribution and is consequently not an original contribution. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and we apologize to readers of the journal that this was not detected during the submission process.

  16. Seasonality and Disturbance Events in the Carbon Isotope Record of Pinus elliottii Tree Rings from Big Pine Key, Florida

    NASA Astrophysics Data System (ADS)

    Rebenack, C.; Anderson, W. T.; Cherubini, P.

    2012-12-01

    The South Florida coastal ecosystem is among the world's subtropical coastlines which are threatened by the potential effects of climate change. A well-developed localized paleohistory is essential in the understanding of the role climate variability/change has on both hydrological dynamics and disturbance event frequency and intensity; this understanding can then aid in the development of better predictive models. High resolution paleoclimate proxies, such as those developed from tree-ring archives, may be useful tools for extrapolating actual climate trends over time from the overlapping long-term and short-term climate cycles, such as the Atlantic Multidecadal Oscillation (AMO) and the El Niño-Southern Oscillation (ENSO). In South Florida, both the AMO and ENSO strongly influence seasonal precipitation, and a more complete grasp of how these cycles have affected the region in the past could be applied to future freshwater management practices. Dendrochronology records for the terrestrial subtropics, including South Florida, are sparse because seasonality for this region is precipitation-driven; this is in contrast to the drastic temperature changes experienced in the temperate latitudes. Subtropical seasonality may lead to the complete lack of visible rings or to the formation of ring structures that may or may not represent annual growth. Fortunately, it has recently been demonstrated that Pinus elliottii trees in South Florida produce distinct annual growth rings; however ring width was not found to significantly correlate with either the AMO or ENSO. Dendrochronology studies may be taken a step beyond the physical tree-ring proxies by using the carbon isotope ratios to infer information about physiological controls and environmental factors that affect the distribution of isotopes within the plant. It has been well established that the stable isotope composition of cellulose can be related to precipitation, drought, large-scale ocean/atmospheric oscillations

  17. A High-Resolution Stalagmite Holocene Paleoclimate Record from Northern Venezuela with Insights into the Timing and Duration of the 8.2 ka Event

    NASA Astrophysics Data System (ADS)

    Retrum, J. B.; Gonzalez, L. A.; Edwards, R.; Cheng, H.; Tincher, S. M.; Urbani, F.

    2013-12-01

    The dearth of studies and data in the tropics hinders our understanding of atmospheric and oceanic interactions between the low latitudes and the rest of the globe. To understand better the interactions, specifically between the Caribbean and the North Atlantic, three stalagmites were collected from Cueva Zarraga in the Falcón Mountains of northwestern Venezuela and analyzed to determine local paleoclimatic history. Stalagmites ages were determined by U/Th disequilibrium and show a nearly complete Holocene record. The stalagmites have an average temporal resolution of 10.8 years/mm and ranges from 2.1 to 62.7 years. Both the carbon and oxygen isotope records preserve quasi-millennial oscillations and show a major depletion shift from the last glacial period into the Holocene, suggesting warmer and wetter conditions during the Holocene. The preservation of quasi-millennial oscillations and of high frequency multi-decadal changes by the δ13C indicates that the soil-vegetation-stalagmite system is acting as an amplifier of the climatic signal produced by climatic events and changes. In the early Holocene, the δ18O record shows a depletion trend from ~ 11,000 to 8,000 cal yr BP before reaching the Holocene Thermal Maximum. A prominent δ18O enrichment event is recorded in all the stalagmites that correspond to the 8.2 ka event. The 8.2 ka event is represented by a double peak with duration of ~ 180 years. Other short-term δ18O enrichment events likely correspond to Bond events 1, 2, 5, and 6. The late Holocene record, like other Caribbean records, indicates that the climate system diverges from insolation and may represent an atmospheric rearrangement that resulted in ENSO increase instability or in reduced seasonal movement of the Inter-Tropical Convergence Zone (ITCZ). Today, Cueva Zarraga is at the northern extent of the ITCZ and has two rainy seasons. The δ18O enrichment events during the Holocene suggest drier conditions southern displacement of the ITCZ

  18. Stable isotope and benthic foraminiferal records of the Latest Danian Event at ODP Site 1262 (Walvis Ridge)

    NASA Astrophysics Data System (ADS)

    Deprez, Arne; Jehle, Sofie; Bornemann, André; Speijer, Robert P.

    2015-04-01

    The Latest Danian Event (LDE - aka Top Chron 27n Event) is characterized by a >1o negative benthic foraminiferal CIE in various sections in Egypt, which has been correlated with δ13C shifts of ~0.7o in Zumaia (Spain), Wombat Plateau (ODP 761B, Indian Ocean) and Shatsky Rise (ODP 1209, Pacific Ocean) (Bornemann et al., 2009; Westerhold et al., 2011). A concurrent ~0.5o δ18O excursion suggests a 2°C bottom water temperature rise during this event at Shatsky Rise, suggesting a hyperthermal nature for this event (Westerhold et al., 2011). Here we show the first results of benthic foraminiferal faunal and isotope patterns related to the LDE at Walvis Ridge (ODP Site 1262, Southern Atlantic Ocean, paleodepth ~3000 m). The high percentage of planktic foraminifera (on average 99.2%) indicates good carbonate preservation. Stable isotope analyses on the benthic foraminifer Nuttallides truempyi show a ~0.9o δ13C shift at ~62.2 Ma. Lowest values are measured at ~62.15 Ma. A concurrent ~0.8o δ18O excursion indicates a ~3°C temperature rise, larger than at Shatsky Rise. δ13C values recover to reach a transient plateau at 0.75o during the second Fe peak (from ~62.1 to 62.0 Ma), coinciding with a second negative δ18O excursion of 0.7o. Also the ODP Site 1209 (Shatsky Rise) record shows these double Fe, δ18O and δ13C peaks. This is a feature that the LDE shares with some early Eocene hyperthermals, like ETM-2/H1-H2 and I1-I2, and might point to a common origin as the early Eocene hyperthermals. The Walvis Ridge samples show a highly diverse assemblage of benthic foraminifera with a relative abundance of 10-15% of Gyroidinoides spp. and ~10% of Nuttallides spp., Siphogenerinoides spp., Gavelinella spp., Epistominella spp. and Cibicidoides spp. The ~15cm sample interval dataset seems to show no large changes in relative abundance of these species at the onset of the LDE. This is different than faunal response to early Eocene hyperthermals, like ETM2. During ETM2 at DSDP

  19. Simulation and prototyping of 2 m long resistive plate chambers for detection of fast neutrons and multi-neutron event identification

    NASA Astrophysics Data System (ADS)

    Elekes, Z.; Aumann, T.; Bemmerer, D.; Boretzky, K.; Caesar, C.; Cowan, T. C.; Hehner, J.; Heil, M.; Kempe, M.; Rossi, D.; Röder, M.; Simon, H.; Sobiella, M.; Stach, D.; Reinhardt, T.; Wagner, A.; Yakorev, D.; Zilges, A.; Zuber, K.; R3B Collaboration

    2013-02-01

    Resistive plate chamber (RPC) prototypes of 2 m length were simulated and built. The experimental tests using a 31 MeV electron beam, discussed in details, showed an efficiency higher than 90% and an excellent time resolution of around σ=100 ps. Furthermore, comprehensive simulations were performed by GEANT4 toolkit in order to study the possible use of these RPCs for fast neutron (200 MeV-1 GeV) detection and multi-neutron event identification. The validation of simulation parameters was carried out via a comparison to experimental data. A possible setup for invariant mass spectroscopy of multi-neutron emission is presented and the characteristics are discussed. The results show that the setup has a high detection efficiency. Its capability of determining the momentum of the outgoing neutrons and reconstructing the relative energy between the fragments from nuclear reactions is demonstrated for different scenarios.

  20. Fast joint detection-estimation of evoked brain activity in event-related FMRI using a variational approach

    PubMed Central

    Chaari, Lotfi; Vincent, Thomas; Forbes, Florence; Dojat, Michel; Ciuciu, Philippe

    2013-01-01

    In standard within-subject analyses of event-related fMRI data, two steps are usually performed separately: detection of brain activity and estimation of the hemodynamic response. Because these two steps are inherently linked, we adopt the so-called region-based Joint Detection-Estimation (JDE) framework that addresses this joint issue using a multivariate inference for detection and estimation. JDE is built by making use of a regional bilinear generative model of the BOLD response and constraining the parameter estimation by physiological priors using temporal and spatial information in a Markovian model. In contrast to previous works that use Markov Chain Monte Carlo (MCMC) techniques to sample the resulting intractable posterior distribution, we recast the JDE into a missing data framework and derive a Variational Expectation-Maximization (VEM) algorithm for its inference. A variational approximation is used to approximate the Markovian model in the unsupervised spatially adaptive JDE inference, which allows automatic fine-tuning of spatial regularization parameters. It provides a new algorithm that exhibits interesting properties in terms of estimation error and computational cost compared to the previously used MCMC-based approach. Experiments on artificial and real data show that VEM-JDE is robust to model mis-specification and provides computational gain while maintaining good performance in terms of activation detection and hemodynamic shape recovery. PMID:23096056

  1. Fast events and waves in an active region of the Sun observed in Hα with high spatial resolution

    NASA Astrophysics Data System (ADS)

    Sánchez-Andrade Nuño, B.; Bello González, N.; Blanco Rodríguez, J.; Kneer, F.; Puschmann, K. G.

    2008-08-01

    Context: We study the chromosphere of an active region of the Sun in the Hα line. Aims: The development of new instrumentation and new methods of data analysis allows to scrutinize the dynamics of the solar chromosphere with high spatial, spectral, and temporal resolution. The observations we present shed light on some magneto-dynamic processes occurring above an active region in the chromosphere. Methods: We took a time series of 55 min in Hα from AR 10875 at θ≈36°. We used the “Göttingen” Fabry-Perot spectrometer at the Vacuum Tower Telescope, Observatorio del Teide/Tenerife, to obtain two-dimensional spectrograms in Hα. Adaptive optics and image reconstruction yielded a spatial resolution better than 0.5 arcsec throughout the time sequence. From the wealth of structures, we selected areas of interest to study further, in detail, some ongoing processes. Results: A small straight surge developed aside of a pore with upward phase speed of 100 km s-1 and line-of-sight (LOS) velocity of 15 km s-1. The surge retreated rapidly with LOS velocity of 45 km s-1 at its mouth. It underwent a rebound and fell back again. Two sympathetic mini-flares were observed that lasted only approximately 40 s, but showed strong Hα emission. We found magnetoacoustic waves in long fibrils as mainly short wave trains, short packets or pulses, i.e., solitary waves consisting of small (1´´-2´´) blobs. They start at either end of the fibrils and travel with phase speeds of 12-14 km s-1, i.e., close to the tube speed and approximately the sound velocity for sufficiently large magnetic field strengths. Some waves speed up to reach velocities of the order of 30 km s-1. This is much lower than the expected Alfvén velocity of ≥200 km s-1 for reasonable magnetic field strengths and mass densities. We suggest that slow waves are not purely longitudinal, but possess gas velocities perpendicular to the direction of propagation of few km s-1. Also, fast waves travel along sinuous

  2. Adverse Event Recording and Reporting in Clinical Trials Comparing Lumbar Disk Replacement with Lumbar Fusion: A Systematic Review.

    PubMed

    Hiratzka, Jayme; Rastegar, Farbod; Contag, Alec G; Norvell, Daniel C; Anderson, Paul A; Hart, Robert A

    2015-12-01

    Study Design Systematic review. Objectives (1) To compare the quality of adverse event (AE) methodology and reporting among randomized trials comparing lumbar fusion with lumbar total disk replacement (TDR) using established AE reporting systems; (2) to compare the AEs and reoperations of lumbar spinal fusion with those from lumbar TDR; (3) to make recommendations on how to report AEs in randomized controlled trials (RCTs) so that surgeons and patients have more-detailed and comprehensive information when making treatment decisions. Methods A systematic search of PubMed, the Cochrane collaboration database, and the National Guideline Clearinghouse through May 2015 was conducted. Randomized controlled trials with at least 2 years of follow-up comparing lumbar artificial disk replacement with lumbar fusion were included. Patients were required to have axial or mechanical low back pain of ≥3 months' duration due to degenerative joint disease defined as degenerative disk disease, facet joint disease, or spondylosis. Outcomes included the quality of AE acquisition methodology and results reporting, and AEs were defined as those secondary to the procedure and reoperations. Individual and pooled relative risks and their 95% confidence intervals comparing lumbar TDR with fusion were calculated. Results RCTs demonstrated a generally poor description of methods for assessing AEs. There was a consistent lack of clear definition or grading for these events. Furthermore, there was a high degree of variation in reporting of surgery-related AEs. Most studies lacked adequate reporting of the timing of AEs, and there were no clear distinctions between acute or chronic AEs. Meta-analysis of the pooled data demonstrated a twofold increased risk of AEs in patients having lumbar fusion compared with patients having lumbar TDR at 2-year follow-up, and this relative risk was maintained at 5 years. Furthermore, the pooled data demonstrated a 1.7 times greater relative risk of

  3. In-Flight Observations of Long-Term Single-Event Effect (SEE) Performance on X-ray Timing Explorer (XTE) Solid-state Recorders (SSRs)

    NASA Technical Reports Server (NTRS)

    Poivey, Christian; Gee, George; LaBel, Kenneth A.; Barth, Janet L.

    2004-01-01

    We present multi-year Single Event Upset (SEU) flight data on Solid State Recorder (SSR) memories for the X-ray Timing Explorer (XTE) NASA mission. Actual SEU rates are compared to the predicted rates based on ground test data and environment models.

  4. Prevalence, nature and potential preventability of adverse drug events – a population-based medical record study of 4970 adults

    PubMed Central

    Hakkarainen, Katja M; Gyllensten, Hanna; Jönsson, Anna K; Andersson Sundell, Karolina; Petzold, Max; Hägg, Staffan

    2014-01-01

    Aims To estimate the 3 month prevalence of adverse drug events (ADEs), categories of ADEs and preventable ADEs, and the preventability of ADEs among adults in Sweden. Further, to identify drug classes and organ systems associated with ADEs and estimate their seriousness. Methods A random sample of 5025 adults in a Swedish county council in 2008 was drawn from the Total Population Register. All their medical records in 29 inpatient care departments in three hospitals, 110 specialized outpatient clinics and 51 primary care units were reviewed retrospectively in a stepwise manner, and complemented with register data on dispensed drugs. ADEs, including adverse drug reactions (ADRs), sub-therapeutic effects of drug therapy (STEs), drug dependence and abuse, drug intoxications from overdose, and morbidities due to drug-related untreated indication, were detected during a 3 month study period, and assessed for preventability. Results Among 4970 included individuals, the prevalence of ADEs was 12.0% (95% confidence interval (CI) 11.1, 12.9%), and preventable ADEs 5.6% (95% CI 5.0, 6.2%). ADRs (6.9%; 95% CI 6.2, 7.6%) and STEs (6.4%; 95% CI 5.8, 7.1%) were more prevalent than the other ADEs. Of the ADEs, 38.8% (95% CI 35.8–41.9%) was preventable, varying by ADE category and seriousness. ADEs were frequently associated with nervous system and cardiovascular drugs, but the associated drugs and affected organs varied by ADE category. Conclusions The considerable burden of ADEs and preventable ADEs from commonly used drugs across care settings warrants large-scale efforts to redesign safer, higher quality healthcare systems. The heterogeneous nature of the ADE categories should be considered in research and clinical practice for preventing, detecting and mitigating ADEs. PMID:24372506

  5. A direct comparison of the ages of detrital monazite versus detrital zircon in Appalachian foreland basin sandstones: Searching for the record of Phanerozoic orogenic events

    NASA Astrophysics Data System (ADS)

    Hietpas, Jack; Samson, Scott; Moecher, David

    2011-10-01

    The provenance potential of detrital monazite was investigated by in situ measurement of 232Th- 208Pb dates of grains isolated from six Middle Carboniferous-Permian sandstones from the Appalachian foreland basin. Provenance assessment of these units was previously investigated by measuring U-Pb crystallization ages of detrital zircon (Thomas et al., 2004; Becker et al., 2005, 2006). Approximately 90% of the detrital zircon ages record Mesoproterozoic or older ages, with only 10% recording the three major pulses of tectonism (Taconian, Acadian and Alleghanian) that are the hallmark of the Appalachian Orogen. 232Th- 208Pb ages of detrital monazite, however, strongly record the complex phases of Paleozoic orogenesis. Nearly 65% of the ages record Paleozoic events, while 35% record Neoproterozoic or older ages. In several of the analyzed sandstones, detrital monazite ages record Paleozoic orogenic events that are completely missed by detrital zircon ages, demonstrating that monazite ages more accurately reflect the character of the sediment source rocks. The inferred maximum age of sediment deposition, as determined by the youngest monazite grains, is ~ 550 Ma younger for two of the analyzed sandstones compared to depositional constraints based on the youngest detrital zircon. The different physical properties and petrogenesis of zircon and monazite are interpreted to be factors for the dramatic differences in sediment provenance information provided by each mineral. The results from this study have important implications for determining sediment provenance, constraining maximum age of sediment deposition, and developing robust regional tectonic models.

  6. Patient-Reported Safety Events in Chronic Kidney Disease Recorded With an Interactive Voice-Inquiry Dial-Response System: Monthly Report Analysis

    PubMed Central

    Doerfler, Rebecca M; Yoffe, Marni R; Diamantidis, Clarissa J; Blumenthal, Jacob B; Siddiqui, Tariq; Gardner, James F; Snitker, Soren; Zhan, Min

    2016-01-01

    Background Monitoring patient-reported outcomes (PROs) may improve safety of chronic kidney disease (CKD) patients. Objective Evaluate the performance of an interactive voice-inquiry dial-response system (IVRDS) in detecting CKD-pertinent adverse safety events outside of the clinical environment and compare the incidence of events using the IVDRS to that detected by paper diary. Methods This was a 6-month study of Stage III-V CKD patients in the Safe Kidney Care (SKC) study. Participants crossed over from a paper diary to the IVDRS for recording patient-reported safety events defined as symptoms or events attributable to medications or care. The IVDRS was adapted from the SKC paper diary to record event frequency and remediation. Participants were auto-called weekly and permitted to self-initiate calls. Monthly reports were reviewed by two physician adjudicators for their clinical significance. Results 52 participants were followed over a total of 1384 weeks. 28 out of 52 participants (54%) reported events using the IVDRS versus 8 out of 52 (15%) with the paper diary; hypoglycemia was the most common event for both methods. All IVDRS menu options were selected at least once except for confusion and rash. Events were reported on 121 calls, with 8 calls reporting event remediation by ambulance or emergency room (ER) visit. The event rate with the IVDRS and paper diary, with and without hypoglycemia, was 26.7 versus 4.7 and 18.3 versus 0.8 per 100 person weeks, respectively (P=.002 and P<.001). The frequent users (ie, >10 events) largely differed by method, and event rates excluding the most frequent user of each were 16.9 versus 2.5 per 100 person weeks, respectively (P<.001). Adjudicators found approximately half the 80 reports clinically significant, with about a quarter judged as actionable. Hypoglycemia was often associated with additional reports of fatigue and falling. Participants expressed favorable satisfaction with the IVDRS. Conclusions Use of the IVDRS

  7. The Use of Continuous Wavelet Transform Based on the Fast Fourier Transform in the Analysis of Multi-channel Electrogastrography Recordings.

    PubMed

    Komorowski, Dariusz; Pietraszek, Stanislaw

    2016-01-01

    This paper presents the analysis of multi-channel electrogastrographic (EGG) signals using the continuous wavelet transform based on the fast Fourier transform (CWTFT). The EGG analysis was based on the determination of the several signal parameters such as dominant frequency (DF), dominant power (DP) and index of normogastria (NI). The use of continuous wavelet transform (CWT) allows for better visible localization of the frequency components in the analyzed signals, than commonly used short-time Fourier transform (STFT). Such an analysis is possible by means of a variable width window, which corresponds to the scale time of observation (analysis). Wavelet analysis allows using long time windows when we need more precise low-frequency information, and shorter when we need high frequency information. Since the classic CWT transform requires considerable computing power and time, especially while applying it to the analysis of long signals, the authors used the CWT analysis based on the fast Fourier transform (FFT). The CWT was obtained using properties of the circular convolution to improve the speed of calculation. This method allows to obtain results for relatively long records of EGG in a fairly short time, much faster than using the classical methods based on running spectrum analysis (RSA). In this study authors indicate the possibility of a parametric analysis of EGG signals using continuous wavelet transform which is the completely new solution. The results obtained with the described method are shown in the example of an analysis of four-channel EGG recordings, performed for a non-caloric meal.

  8. Cenozoic prograding sequences of the Antarctic continental margin: a record of glacio-eustatic and tectonic events

    USGS Publications Warehouse

    Cooper, A. K.; Barrett, P.J.; Hinz, K.; Traube, V.; Letichenkov, G.; Stagg, H.M.J.

    1991-01-01

    times, like today, by little or no clastic sedimentation on the continental shelf other than beneath retreated ice shelves lying far from the continental sheld edge. Ice streams carve broad depressions across the shelf and carry abundant basal sediments directly to the continental shelf edge, thereby creating troughmouth fans and sheet-like prograding sequences (i.e. type IA sequences). Numerous acoustic unconformities and multiple overcompacted layers within the prograding sequences suggest major fluctuations of the Antarctic Ice Sheet. The available drilling and seismic interpretations provide the following history: (1) Cenozoic ice sheets have existed in places near the continental shelf since middle to late Eocene time. (2) A grounded Antarctic ice sheet first expanded to the continental shelf edge, with probable overdeepening of the outer shelf, in late Eucene to early Oligocene time in Prydz Bay, possibly in early Miocene time in the Ross Sea, and at least by middle Miocene time in the Weddell Sea. (3) The relative amounts of shelf prograding and inferred ice-volume variations (and related sea-level changes) have increased since middle to late Miocene time in the eastern Ross Sea, Prydz Bay, and possibly Weddell Sea. Our analysis is preliminary. Further acoustic surveys and scientific drilling are needed to resolve the proximal Antarctic record of glacio-eustatic, climatic, and tectonic events recorded by the prograding sequences. ?? 1991.

  9. Pattern of presenting complaints recorded as near-drowning events in emergency departments: a national surveillance study from Pakistan

    PubMed Central

    2015-01-01

    Background Drowning is a heavy burden on the health systems of many countries, including Pakistan. To date, no effective large-scale surveillance has been in place to estimate rates of drowning and near-drowning in Pakistan. The Pakistan National Emergency Department Surveillance (Pak-NEDS) study aimed to fill this gap. Methods Patients who presented with a complaint of "near-drowning" were analyzed to explore patterns of true near-drowning (unintentional) and intentional injuries that led to the "near-drowning" complaint. Bivariate analysis was done to establish patterns among patients treated in emergency departments, including socio-demographic information, injury-related information, accompanying injuries, and emergency department resource utilization. Results A total of 133 patients (0.2% of all injury patients) with "near-drowning" as presenting complaints were recorded by the Pak-NEDS system. True near-drowning (50.0%) and intentional injuries that led to "near-drowning" complaints (50.0%) differed in nature of injuries. The highest proportion of true near-drowning incidents occurred among patients aged between 25-44 years (47.5%), and among males (77.5%). True near-drowning patients usually had other accompanying complaints, such as lower limb injury (40.0%). Very few patients were transported by ambulance (5.0%), and triage was done for 15% of patients. Eleven (27.5%) true near-drowning patients received cardiopulmonary resuscitation. Conclusion There was major under-reporting of drowning and near-drowning cases in the surveillance study. The etiology of near-drowning cases should be further studied. Patients who experienced non-fatal drownings were more commonly sent for medical care due to other accompanying conditions, rather than near-drowning event itself. There is also need for recognizing true near-drowning incidents. The results of this study provide information on data source selection, site location, emergency care standardization, and multi

  10. Records of past mid-depth ventilation: Cretaceous ocean anoxic event 2 vs. Recent oxygen minimum zones

    NASA Astrophysics Data System (ADS)

    Schönfeld, J.; Kuhnt, W.; Erdem, Z.; Flögel, S.; Glock, N.; Aquit, M.; Frank, M.; Holbourn, A.

    2015-02-01

    Present day oceans are well ventilated, with the exception of mid-depth oxygen minimum zones (OMZs) under high surface water productivity, regions of sluggish circulation, and restricted marginal basins. In the Mesozoic, however, entire oceanic basins transiently became dysoxic or anoxic. The Cretaceous ocean anoxic events (OAEs) were characterised by laminated organic-carbon rich shales and low-oxygen indicating trace fossils preserved in the sedimentary record. Yet assessments of the intensity and extent of Cretaceous near-bottom water oxygenation have been hampered by deep or long-term diagenesis and the evolution of marine biota serving as oxygen indicators in today's ocean. Sedimentary features similar to those found in Cretaceous strata were observed in deposits underlying Recent OMZs, where bottom-water oxygen levels, the flux of organic matter, and benthic life have been studied thoroughly. Their implications for constraining past bottom-water oxygenation are addressed in this review. We compared OMZ sediments from the Peruvian upwelling with deposits of the late Cenomanian OAE 2 from the north-west African shelf. Holocene laminated sediments are encountered at bottom-water oxygen levels of < 7 μmol kg-1 under the Peruvian upwelling and < 5 μmol kg-1 in California Borderland basins and the Pakistan Margin. Seasonal to decadal changes of sediment input are necessary to create laminae of different composition. However, bottom currents may shape similar textures that are difficult to discern from primary seasonal laminae. The millimetre-sized trace fossil Chondrites was commonly found in Cretaceous strata and Recent oxygen-depleted environments where its diameter increased with oxygen levels from 5 to 45 μmol kg-1. Chondrites has not been reported in Peruvian sediments but centimetre-sized crab burrows appeared around 10 μmol kg-1, which may indicate a minimum oxygen value for bioturbated Cretaceous strata. Organic carbon accumulation

  11. Uncovering a Salt Giant. Deep-Sea Record of Mediterranean Messinian Events (DREAM) multi-phase drilling project

    NASA Astrophysics Data System (ADS)

    Camerlenghi, Angelo; Aoisi, Vanni; Lofi, Johanna; Hübscher, Christian; deLange, Gert; Flecker, Rachel; Garcia-Castellanos, Daniel; Gorini, Christian; Gvirtzman, Zohar; Krijgsman, Wout; Lugli, Stefano; Makowsky, Yizhaq; Manzi, Vinicio; McGenity, Terry; Panieri, Giuliana; Rabineau, Marina; Roveri, Marco; Sierro, Francisco Javier; Waldmann, Nicolas

    2014-05-01

    In May 2013, the DREAM MagellanPlus Workshop was held in Brisighella (Italy). The initiative builds from recent activities by various research groups to identify potential sites to perform deep-sea scientific drilling in the Mediterranean Sea across the deep Messinian Salinity Crisis (MSC) sedimentary record. In this workshop three generations of scientists were gathered: those who participated in formulation of the deep desiccated model, through DSDP Leg 13 drilling in 1973; those who are actively involved in present-day MSC research; and the next generation (PhD students and young post-docs). The purpose of the workshop was to identify locations for multiple-site drilling (including riser-drilling) in the Mediterranean Sea that would contribute to solve the several open questions still existing about the causes, processes, timing and consequences at local and planetary scale of an outstanding case of natural environmental change in the recent Earth history: the Messinian Salinity Crisis in the Mediterranean Sea. The product of the workshop is the identification of the structure of an experimental design of site characterization, riser-less and riser drilling, sampling, measurements, and down-hole analyses that will be the core for at least one compelling and feasible multiple phase drilling proposal. Particular focus has been given to reviewing seismic site survey data available from different research groups at pan-Mediterranean basin scale, to the assessment of additional site survey activity including 3D seismics, and to ways of establishing firm links with oil and gas industry. The scientific community behind the DREAM initiative is willing to proceed with the submission to IODP of a Multi-phase Drilling Project including several drilling proposals addressing specific drilling objectives, all linked to the driving objectives of the MSC drilling and understanding . A series of critical drilling targets were identified to address the still open questions

  12. Parvalbumin-immunoreactive, fast-spiking neurons in the medial septum/diagonal band complex of the rat: intracellular recordings in vitro.

    PubMed

    Morris, N P; Harris, S J; Henderson, Z

    1999-01-01

    The medial septum/diagonal band complex is composed predominantly of cholinergic and GABAergic neurons, and it projects to the hippocampal formation. A proportion of the GABAergic neurons contain parvalbumin, a calcium-binding protein that has previously been localized in fast-spiking, non-accommodating GABAergic neurons in the cerebral cortex and neostriatum. The aim of the present study was to determine whether parvalbumin is localized preferentially in a similar electrophysiological class of neuron in the medial septum/diagonal band complex. The study was carried out using in vitro intracellular recording, intracellular biocytin filling and parvalbumin immunocytochemistry. Three main classes of neurons were identified according to standard criteria: burst-firing, slow-firing and fast-firing neuronal populations. The fast-firing neurons were subdivided into two subpopulations based on whether or not they displayed accommodation. The fast-spiking, non-accommodating cells were furthermore found to be spontaneously active at resting potentials, and to possess action potentials of significantly (P < 0.05) shorter duration (half width: 0.61 +/- 0.12 ms) than those of the regular-spiking, accommodating neurons (1.0 +/- 0.34 ms). Of the neurons that were successfully filled with biocytin and processed for parvalbumin immunoreactivity, 82% of the fast-spiking, non-accommodating cells possessed parvalbumin immunoreactivity, while none of the regular-spiking, accommodating neurons were found to be immunoreactive for parvalbumin. The slow-firing neurons, shown previously to be cholinergic, did not stain for parvalbumin immunoreactivity, in agreement with studies showing parvalbumin to be localized solely in GABAergic neurons in the medial septum/diagonal band complex. In conclusion, these findings suggest the presence of a previously uncharacterized population of neurons in the medial septum/diagonal band complex that generate high-frequency, non-adaptive discharge. This

  13. How fast was the Matuyama-Brunhes geomagnetic reversal? A new subcentennial record from the Sulmona Basin, central Italy

    NASA Astrophysics Data System (ADS)

    Sagnotti, Leonardo; Giaccio, Biagio; Liddicoat, Joseph C.; Nomade, Sebastien; Renne, Paul R.; Scardia, Giancarlo; Sprain, Courtney J.

    2016-02-01

    A recent study of the Matuyama-Brunhes (M-B) geomagnetic field reversal recorded in exposed lacustrine sediments from the Sulmona Basin (Italy) provided a continuous, high-resolution record indicating that the reversal of the field direction at the terminus of the M-B boundary (MBB) occurred in less than a century, about 786 ka ago. In the sediment, thin (4-6 cm) remagnetized horizons were recognized above two distinct tephra layers-SUL2-19 and SUL2-20-that occur ˜25 and ˜35 cm below the MBB, respectively. Also, a faint, millimetre-thick tephra (SUL2-18) occurs 2-3 cm above the MBB. With the aim of improving the temporal resolution of the previous Sulmona MBB record and understanding the possible influence of cryptotephra on the M-B record in the Sulmona Basin, we performed more detailed sampling and analyses of overlapping standard and smaller samples from a 50 cm-long block that spans the MBB. The new data indicate that (i) the MBB is even sharper than previously reported and occurs ˜2.5 cm below tephra SUL2-18, in agreement with the previous study; (ii) the MBB coincides with the rise of an intensity peak of the natural remanent magnetization (NRM) intensity, which extends across SUL2-18; (iii) except for a 2-cm-thick interval just above tephra SUL2-18, the rock magnetic parameters (k, ARM, Mr, Ms, Bc, Bcr) indicate exactly the same magnetic mineralogy throughout the sampled sequence. We conclude that either SUL2-18 resulted in the remagnetization of an interval of about 6 cm (i.e. during the NRM intensity peak spanning ˜260 ± 110 yr, according to the estimated local sedimentation rate), and thus the detailed MBB record is lost because it is overprinted, or the MBB is well recorded, occurred abruptly about 2.5 cm below SUL2-18 and lasted less than 13 ± 6 yr. Both hypotheses challenge our understanding of the geomagnetic field behaviour during a polarity transition and/or of the NRM acquisition process in the Sulmona lacustrine sediment.

  14. Tephrochronology and the extended intimate (integration of ice-core, marine and terrestrial records) event stratigraphy 8-128 ka b2k

    NASA Astrophysics Data System (ADS)

    Blockley, Simon P. E.; Bourne, Anna J.; Brauer, Achim; Davies, Siwan M.; Hardiman, Mark; Harding, Poppy R.; Lane, Christine S.; MacLeod, Alison; Matthews, Ian P.; Pyne-O'Donnell, Sean D. F.; Rasmussen, Sune O.; Wulf, Sabine; Zanchetta, Giovanni

    2014-12-01

    The comparison of palaeoclimate records on their own independent timescales is central to the work of the INTIMATE (INTegrating Ice core, MArine and TErrestrial records) network. For the North Atlantic region, an event stratigraphy has been established from the high-precision Greenland ice-core records and the integrated GICC05 chronology. This stratotype provides a palaeoclimate signal to which the timing and nature of palaeoenvironmental change recorded in marine and terrestrial archives can be compared. To facilitate this wider comparison, without assuming synchroneity of climatic change/proxy response, INTIMATE has also focussed on the development of tools to achieve this. In particular the use of time-parallel marker horizons e.g. tephra layers (volcanic ash). Coupled with the recent temporal extension of the Greenland stratotype, as part of this special issue, we present an updated INTIMATE event stratigraphy highlighting key tephra horizons used for correlation across Europe and the North Atlantic. We discuss the advantages of such an approach, and the key challenges for the further integration of terrestrial palaeoenvironmental records with those from ice cores and the marine realm.

  15. Coral-based climate records from tropical South Atlantic: 2009/2010 ENSO event in C and O isotopes from Porites corals (Rocas Atoll, Brazil).

    PubMed

    Pereira, Natan S; Sial, Alcídes N; Kikuchi, Ruy K P; Ferreira, Valderez P; Ullmann, Clemens V; Frei, Robert; Cunha, Adriana M C

    2015-01-01

    Coral skeletons contain records of past environmental conditions due to their long life span and well calibrated geochemical signatures. C and O isotope records of corals are especially interesting, because they can highlight multidecadal variability of local climate conditions beyond the instrumental record, with high fidelity and sub-annual resolution. Although, in order to get an optimal geochemical signal in coral skeleton, sampling strategies must be followed. Here we report one of the first coral-based isotopic record from the Equatorial South Atlantic from two colonies of Porites astreoides from the Rocas Atoll (offshore Brazil), a new location for climate reconstruction. We present time series of isotopic variation from profiles along the corallite valley of one colony and the apex of the corallite fan of the other colony. Significant differences in the isotopic values between the two colonies are observed, yet both record the 2009/2010 El Niño event - a period of widespread coral bleaching - as anomalously negative δ18O values (up to -1 permil). δ13C is found to be measurably affected by the El Niño event in one colony, by more positive values (+0.39 ‰), and together with a bloom of endolithic algae, may indicate physiological alteration of this colony. Our findings indicate that corals from the Rocas Atoll can be used for monitoring climate oscillations in the tropical South Atlantic Ocean. PMID:26536856

  16. Coral-based climate records from tropical South Atlantic: 2009/2010 ENSO event in C and O isotopes from Porites corals (Rocas Atoll, Brazil).

    PubMed

    Pereira, Natan S; Sial, Alcídes N; Kikuchi, Ruy K P; Ferreira, Valderez P; Ullmann, Clemens V; Frei, Robert; Cunha, Adriana M C

    2015-01-01

    Coral skeletons contain records of past environmental conditions due to their long life span and well calibrated geochemical signatures. C and O isotope records of corals are especially interesting, because they can highlight multidecadal variability of local climate conditions beyond the instrumental record, with high fidelity and sub-annual resolution. Although, in order to get an optimal geochemical signal in coral skeleton, sampling strategies must be followed. Here we report one of the first coral-based isotopic record from the Equatorial South Atlantic from two colonies of Porites astreoides from the Rocas Atoll (offshore Brazil), a new location for climate reconstruction. We present time series of isotopic variation from profiles along the corallite valley of one colony and the apex of the corallite fan of the other colony. Significant differences in the isotopic values between the two colonies are observed, yet both record the 2009/2010 El Niño event - a period of widespread coral bleaching - as anomalously negative δ18O values (up to -1 permil). δ13C is found to be measurably affected by the El Niño event in one colony, by more positive values (+0.39 ‰), and together with a bloom of endolithic algae, may indicate physiological alteration of this colony. Our findings indicate that corals from the Rocas Atoll can be used for monitoring climate oscillations in the tropical South Atlantic Ocean.

  17. Surge Driven Return Flow Results in Deposition of Coarse Grain Horizons Archiving a 4000 Year Record of Extreme Storm Events, Cape Cod, Massachusetts

    NASA Astrophysics Data System (ADS)

    Maio, C. V.; Donnelly, J. P.; Sullivan, R.; Weidman, C. R.; Sheremet, V.

    2014-12-01

    The brevity of the instrumental record and lack of detailed historical accounts is a limiting factor in our understanding of the relationship between climate change and the frequency and intensity of extreme storm events. This study applied paleotempestologic and hydrographic methods to identify the mechanisms of storm-induced coarse grain deposition and reconstruct a late Holocene storm record within Waquoit Bay, Massachusetts. Three sediment cores (6.0 m, 8.4 m, and 8.2 m) were collected in 3 m of water using a vibracore system. Grain sizes were measured along core to identify coarse grain anomalies that serve as a proxy for past storm events. An historical age model (1620-2011 AD) was developed based on Pb pollution chronomarkers derived from X-Ray Florescence bulk Pb data, equating to a sedimentation rate of 8-8.3 mm/yr (R2 = 0.99). A long-term (4000 to 275 years before present) sedimentation rate of 1.1-1.4 mm/yr (R2 = 0.89) was calculated based on twenty-four continuous flow atomic mass spectrometry 14C ages of marine bivalves. To determine hydrographic conditions within the embayment during storm events current meters and tide gauges were deployed during Hurricane Irene (2011) which measured a storm surge of 88 cm above mean sea level. The buildup of storm water against the landward shoreline resulted in a measured 10 cm/s seaward moving bottom current capable of transporting coarse sand eroded from the adjacent shoreface into the coring site. Modeled surges for eleven modern and historic storm events ranged in height from 0.37 m (2011) to 3.72 m (1635) above mean high water. The WAQ1, WAQ2, and WAQ3 cores recorded a total of 89, 139, and 137 positive anomalies that exceeded the lower threshold and 15, 34, and 12 that exceeded the upper threshold respectively. Events recorded during the historic period coincide with documented storm events. The mean frequency within the three cores applying the lower threshold was 2.6 events per century, while applying the

  18. An account of a flare related shock event recorded by the energetic particle detector EPONA of the Giotto spacecraft during September 1985 (STIP interval 18)

    NASA Technical Reports Server (NTRS)

    Mckennalawlor, Susan M. P.; Kirsch, E.; Daly, P.; Osullivan, D.; Thompson, A.; Wenzel, P-K

    1987-01-01

    The Energetic Particle Detector EPONA flown on the Giotto Mission to Halley's Comet was designed to measure electrons, protons, and heavier ions (E greater that 20 keV) in the Comet Halley environment and during the Cruise Phase of the mission (EPONA switch on: 22 August 1985 - Halley encounter: 13 March 1986). In September 1985 (STIP Interval XVIII) a well defined shock event was recorded at EPONA in association with a sequence of solar flares and a preliminary account of this event is presented.

  19. Identification of Paleo-Events Recorded in the Yellow Sea Sediments by Sorting Coefficient of Grain Size

    PubMed Central

    Wang, Yuhong; Cheng, Wenhan; Jia, Nan

    2012-01-01

    Identification of natural and anthropogenic events in the past is important for studying their patterns and mechanisms; and sensitive proxies in marine sediments are more reliable for identifying these events than those in terrestrial sediments, which are usually disturbed by human activities. Since the main source materials for the sediments in the Northern Yellow Sea Mud are transported by the Yellow River, sedimentary characteristics can be used to reconstruct the historical events that occurred in the Yellow River Valley. In the present study, by analyzing sorting coefficient of grain size in a 250-year sediment core from the Northern Yellow Sea Mud, we identified several major historical events: the Haiyuan Earthquake in AD 1920 and several times of relocation of the Yellow River estuary. The proxy has the potential of detecting and reconstructing historical events; in combination with historical archives, they also provide an accurate dating method. PMID:22970299

  20. A System for Reflective Learning Using Handwriting Tablet Devices for Real-Time Event Bookmarking into Simultaneously Recorded Videos

    ERIC Educational Resources Information Center

    Nakajima, Taira

    2012-01-01

    The author demonstrates a new system useful for reflective learning. Our new system offers an environment that one can use handwriting tablet devices to bookmark symbolic and descriptive feedbacks into simultaneously recorded videos in the environment. If one uses video recording and feedback check sheets in reflective learning sessions, one can…

  1. A stratigraphic framework for abrupt climatic changes during the Last Glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event stratigraphy

    NASA Astrophysics Data System (ADS)

    Rasmussen, Sune O.; Bigler, Matthias; Blockley, Simon P.; Blunier, Thomas; Buchardt, Susanne L.; Clausen, Henrik B.; Cvijanovic, Ivana; Dahl-Jensen, Dorthe; Johnsen, Sigfus J.; Fischer, Hubertus; Gkinis, Vasileios; Guillevic, Myriam; Hoek, Wim Z.; Lowe, J. John; Pedro, Joel B.; Popp, Trevor; Seierstad, Inger K.; Steffensen, Jørgen Peder; Svensson, Anders M.; Vallelonga, Paul; Vinther, Bo M.; Walker, Mike J. C.; Wheatley, Joe J.; Winstrup, Mai

    2014-12-01

    Due to their outstanding resolution and well-constrained chronologies, Greenland ice-core records provide a master record of past climatic changes throughout the Last Interglacial-Glacial cycle in the North Atlantic region. As part of the INTIMATE (INTegration of Ice-core, MArine and TErrestrial records) project, protocols have been proposed to ensure consistent and robust correlation between different records of past climate. A key element of these protocols has been the formal definition and ordinal numbering of the sequence of Greenland Stadials (GS) and Greenland Interstadials (GI) within the most recent glacial period. The GS and GI periods are the Greenland expressions of the characteristic Dansgaard-Oeschger events that represent cold and warm phases of the North Atlantic region, respectively. We present here a more detailed and extended GS/GI template for the whole of the Last Glacial period. It is based on a synchronization of the NGRIP, GRIP, and GISP2 ice-core records that allows the parallel analysis of all three records on a common time scale. The boundaries of the GS and GI periods are defined based on a combination of stable-oxygen isotope ratios of the ice (δ18O, reflecting mainly local temperature) and calcium ion concentrations (reflecting mainly atmospheric dust loading) measured in the ice. The data not only resolve the well-known sequence of Dansgaard-Oeschger events that were first defined and numbered in the ice-core records more than two decades ago, but also better resolve a number of short-lived climatic oscillations, some defined here for the first time. Using this revised scheme, we propose a consistent approach for discriminating and naming all the significant abrupt climatic events of the Last Glacial period that are represented in the Greenland ice records. The final product constitutes an extended and better resolved Greenland stratotype sequence, against which other proxy records can be compared and correlated. It also provides a

  2. A complete high resolution record of the Dan-C2 hyperthermal event in the lacustrine sediments of the Boltysh Impact crater

    NASA Astrophysics Data System (ADS)

    Gilmour, I.; Jolley, D. W.; Daly, R. J.; Kelley, S. P.; Gilmour, M. A.

    2012-04-01

    Drilling of the 65.17 Ma old, 24 km diameter, Boltysh impact crater in the Ukraine recovered over 400 m of Danian organic-rich lacustrine sediments [1]. We have undertaken geochemical and palynological investigations of the newly cored borehole, which demonstrate that these strata contain a unique high resolution record spanning <0.5 Ma of Early Palaeocene terrestrial environmental change. The palynofloras recovered are consistent with terrestrial early Danian successions and geochemical data have highlighted a record that extends through 220m of cored sediments encompassing the earliest Danian Dan-C2 hyperthermal event first identified by [2]. To date, the Dan-C2 hyperthermal event has been identified in marine records, where it is characterised by a pair of negative carbon isotope excursions (CIEs) of around 1.5‰ within planktonic foraminiferal zone P1a, post-dating the K/Pg boundary. Geochemical and palynological investigations have enabled us to identify the Dan-C2 event in the lacustrine Boltysh crater fill where it is characterised by a 3-4‰ negative CIE. In common with other hyperthermal events, it has been suggested that the Dan-C2 reflects transient perturbations in the global carbon cycle, however, whether the Dan-C2 is a global event has been disputed. The event has been confirmed in the S. Atlantic but was not found in the equatorial Pacific leading to the suggestion that it was restricted to the Atlantic Ocean [3]. Its presence in the lacustrine sediments of the Boltysh crater fill disproves this contention. The Dan-C2 CIE has also been regarded as being of shorter duration and lower magnitude than the PETM hyperthermal [2]. This view is brought into question by the Boltysh carbon isotope record, which highlights the close comparability of Toarcian, Dan-C2 and PETM excursions. We have also have established the position of the Dan-C2 with respect to the K/Pg boundary [1] since its close proximity this boundary, also marked by a negative CIE, makes

  3. Practical modifications to the Time-to-Event Continual Reassessment Method for phase I cancer trials with fast patient accrual and late-onset toxicities

    PubMed Central

    Polley, Mei-Yin C.

    2014-01-01

    The goal of phase I cancer trials is to determine the highest dose of a treatment regimen with an acceptable toxicity rate. Traditional designs for phase I trials, such as the Continual Reassessment Method (CRM) and the 3+3 design, require each patient or a cohort of patients to be fully evaluated for the dose-limiting toxicity (DLT) before new patients can be enrolled. As such, the trial duration may be prohibitively long. The Time-to-Event Continual Reassessment Method (TITE-CRM, Cheung and Chappell, 2000) circumvents this limitation by allowing staggered patient accrual without the need for complete DLT follow-up of previously treated patients. However, in the setting of fast patient accrual and late-onset toxicities, the TITE-CRM results in overly aggressive dose escalation and exposes a considerable number of patients to toxic doses. We examine a modification to the TITE-CRM proposed by the original TITE-CRM creator and propose an alternative approach useful in this setting by incorporating an accrual suspension rule. A simulation study designed based on a neuro-oncology trial indicates that the modified methods provide a much improved degree of safety than the TITE-CRM while maintaining desirable design accuracy. The practical aspects of the proposed designs are discussed. The modifications presented are useful when planning phase I trials involving chemoradiation therapy. PMID:21590790

  4. Advance Liquid Metal Reactor Discrete Dynamic Event Tree/Bayesian Network Analysis and Incident Management Guidelines (Risk Management for Sodium Fast Reactors)

    SciTech Connect

    Denman, Matthew R.; Groth, Katrina M.; Cardoni, Jeffrey N.; Wheeler, Timothy A.

    2015-04-01

    Accident management is an important component to maintaining risk at acceptable levels for all complex systems, such as nuclear power plants. With the introduction of self-correcting, or inherently safe, reactor designs the focus has shifted from management by operators to allowing the system's design to manage the accident. Inherently and passively safe designs are laudable, but nonetheless extreme boundary conditions can interfere with the design attributes which facilitate inherent safety, thus resulting in unanticipated and undesirable end states. This report examines an inherently safe and small sodium fast reactor experiencing a beyond design basis seismic event with the intend of exploring two issues : (1) can human intervention either improve or worsen the potential end states and (2) can a Bayesian Network be constructed to infer the state of the reactor to inform (1). ACKNOWLEDGEMENTS The authors would like to acknowledge the U.S. Department of Energy's Office of Nuclear Energy for funding this research through Work Package SR-14SN100303 under the Advanced Reactor Concepts program. The authors also acknowledge the PRA teams at Argonne National Laboratory, Oak Ridge National Laboratory, and Idaho National Laboratory for their continue d contributions to the advanced reactor PRA mission area.

  5. A High-Resolution Labrador Sea Surface and Subsurface Water Foraminiferal δ18O Record and its Relation to Heinrich Events.

    NASA Astrophysics Data System (ADS)

    Brown, Z. E.; Hoffman, J. S.; Clark, P. U.

    2015-12-01

    Heinrich events are characterized by episodic iceberg discharge events from the Laurentide ice sheet via the Hudson Strait Ice Stream (HSIS) and into the North Atlantic. Although their occurrence throughout late Pleistocene glaciations has been well documented in the oceanic sediment record, the triggering mechanism for Heinrich events is still poorly understood. Recent work (Marcott et al., 2011) has shown that subsurface ocean (~1200 m) warming in response to a shutdown of the Atlantic Meridional Overturning Circulation (AMOC) could lead to accelerated melting and destabilization of an ice shelf fronting the Laurentide Ice Sheet and subsequently trigger Heinrich events. However, evidence for this subsurface warming remains restricted to one core site. Here we use Labrador Sea cores HU2001043-008pc/twc and HU2006040-006pc from the Flemish Cap and Hamilton Spur, respectively, to assess spatial and depth coverage of this signal. We infer surface and subsurface temperature variability using δ18O in benthic and planktic foraminifera. We also develop a corresponding suite of other sediment core proxies in order to identify Heinrich layers, including X-Ray Fluorescence, Ca/Sr, and % dolomite/calcite data. This research will allow us to evaluate changes in the thermodynamic structure of the Labrador basin due to changes in the strength of the AMOC and their relation to Heinrich events. Results will be used to substantiate existing research and coupled ocean-atmospheric models that suggest a reduced AMOC and associated subsurface warming as the trigger for Heinrich events.

  6. Searching for events in Chinese ancient records to explain the increase in 14C from AD 774-775 and AD 993-994

    NASA Astrophysics Data System (ADS)

    Chai, Ya-Ting; Zou, Yuan-Chuan

    2015-09-01

    According to analysis of the 14C content in two Japanese trees, that grew over a period of approximately 3000 years, with high time resolution, Miyake et al. found a rapid increase at AD 774-775 and another one at AD 993-994. These increases correspond to high-energy events that happened within those years and radiated γ-ray energy of about 7×1024 erg toward the Earth. The origin of these events is a mystery. Such strong events should have an unusual optical counterpart, and have been recorded in historical literatures. We searched Chinese historical materials around AD 744-775 and AD 993-994, but no remarkable event was found except for a violent thunderstorm in AD 775. However, the possibility of a thunderstorm containing so much energy is unlikely. We conclude that the events, which caused the 14C increase, are still unclear. These events most probably had no optical counterpart, and a short gamma-ray burst, giant flare of a soft gamma-ray repeater or a terrestrial γ-ray flash could all be candidates.

  7. Recovering Paleo-Records from Antarctic Ice-Cores by Coupling a Continuous Melting Device and Fast Ion Chromatography.

    PubMed

    Severi, Mirko; Becagli, Silvia; Traversi, Rita; Udisti, Roberto

    2015-11-17

    Recently, the increasing interest in the understanding of global climatic changes and on natural processes related to climate yielded the development and improvement of new analytical methods for the analysis of environmental samples. The determination of trace chemical species is a useful tool in paleoclimatology, and the techniques for the analysis of ice cores have evolved during the past few years from laborious measurements on discrete samples to continuous techniques allowing higher temporal resolution, higher sensitivity and, above all, higher throughput. Two fast ion chromatographic (FIC) methods are presented. The first method was able to measure Cl(-), NO3(-) and SO4(2-) in a melter-based continuous flow system separating the three analytes in just 1 min. The second method (called Ultra-FIC) was able to perform a single chromatographic analysis in just 30 s and the resulting sampling resolution was 1.0 cm with a typical melting rate of 4.0 cm min(-1). Both methods combine the accuracy, precision, and low detection limits of ion chromatography with the enhanced speed and high depth resolution of continuous melting systems. Both methods have been tested and validated with the analysis of several hundred meters of different ice cores. In particular, the Ultra-FIC method was used to reconstruct the high-resolution SO4(2-) profile of the last 10,000 years for the EDML ice core, allowing the counting of the annual layers, which represents a key point in dating these kind of natural archives.

  8. Strong fast long-period waves in the Efpalio 2010 earthquake records: explanation in terms of leaking modes

    NASA Astrophysics Data System (ADS)

    Vackář, Jiří; Zahradník, Jiří; Sokos, Efthimios

    2014-01-01

    The January 18, 2010, shallow earthquake in the Corinth Gulf, Greece ( M w 5.3) generated unusually strong long-period waves (periods 4-8 s) between the P and S wave arrival. These periods, being significantly longer than the source duration, indicated a structural effect. The waves were observed in epicentral distances 40-250 km and were significant on radial and vertical component. None of existing velocity models of the studied region provided explanation of the waves. By inverting complete waveforms, we obtained an 1-D crustal model explaining the observation. The most significant feature of the best-fitting model (as well as the whole suite of models almost equally well fitting the waveforms) is a strong velocity step at depth about 4 km. In the obtained velocity model, the fast long-period wave was modeled by modal summation and identified as a superposition of several leaking modes. In this sense, the wave is qualitatively similar to P long or Pnl waves, which however are usually reported in larger epicentral distances. The main innovation of this paper is emphasis to smaller epicentral distances. We studied properties of the wave using synthetic seismograms. The wave has a normal dispersion. Azimuthal and distance dependence of the wave partially explains its presence at 46 stations of 70 examined. Depth dependence shows that the studied earthquake was very efficient in the excitation of these waves just due to its shallow centroid depth (4.5 km).

  9. The Carrington event from August 28 to September 5, 1859 : impact on communications, atmospheric chemistry and economy from the historical record.

    NASA Astrophysics Data System (ADS)

    Muller, Christian

    2013-04-01

    The beginning of September 1859 was the occasion of the first and unique observation of a giant solar white light flare, auroral displays were observed at low latitudes and geomagnetic observatories recorded an exceptional storm. The intention of this communication is to review the impact of the event on the telegraphic network as it was described by various authors at the time including Adolphe Quételet in Brussels. The techniques used by the operators to mitigate the effects will be described. An attempt to quantify the phenomenon will be made in terms of induced currents on the telegraphic lines. The economic consequences at the time will be assessed from a press review. The scientific literature indicates also effects on atmospheric "ozone" measured with the techniques of the time. The values of these observations and what they could teach us on the chemical changes associated with the event will be discussed. Comparisons with later solar flare events will be attempted on the basis of the record and the consequences of an event of comparable magnitude to the 1859 set of flares will be discussed.

  10. Coral record of paleoseismic uplifts at Ranongga Island, Western Solomon Islands megathrust: Was the 2007 Mw 8.1 event smaller than usual?

    NASA Astrophysics Data System (ADS)

    Taylor, F. W.; Thirumalai, K.; Shen, C.; WU, C.; Papabatu, A.; Lavier, L. L.; Bevis, M. G.

    2012-12-01

    The timing and amount of vertical displacements associated with past megathrust earthquakes provide the best available insights into the amounts of interplate slip that have been accommodated as coseismic slip versus other mechanisms. At Ranongga Island, Western Solomon Islands, a Mw 8.1 earthquake in 2007 helps us to calibrate the relationship between a megathrust rupture and the geography and amounts of vertical displacement recorded by reef crest corals. Along the coasts of Ranongga, parts of which have uplifted at mean rates exceeding 5 mm/yr, we discovered corals that had been raised by a series of earthquakes in the millennia before the 2007 event. The penultimate earthquake (pre-2007), which occurred around 600 years ago (U-series calendar year), was manifest as a 'level' of raised corals about 1.6 m above the 2007 level. However, in the decades preceding the 2007 event (which had imposed a coseismic uplift of 1.3 m), rapid subsidence had subtracted significant amounts of uplift imposed by the penultimate earthquake. Similarly, the sequence of three additional uplift events, preceding the penultimate event, extending to elevations up to 16 m higher than the corals raised by the 2007 event, appear to have been larger uplifts than the 2007 event. This suggests two things: 1. Many previous megathrust events caused more uplift and perhaps involved greater interplate coseismic slip, and 2. There are too few megathrust rupture events to account for the approximately 80-100 m of plate convergence that must be processed each millennium. Thus, a significant amount of plate convergence must be accommodated by mechanisms other than coseismic slip.

  11. Detection and Magnetic Source Imaging of Fast Oscillations (40-160 Hz) Recorded with Magnetoencephalography in Focal Epilepsy Patients.

    PubMed

    von Ellenrieder, Nicolás; Pellegrino, Giovanni; Hedrich, Tanguy; Gotman, Jean; Lina, Jean-Marc; Grova, Christophe; Kobayashi, Eliane

    2016-03-01

    We present a framework to detect fast oscillations (FOs) in magnetoencephalography (MEG) and to perform magnetic source imaging (MSI) to determine the location and extent of their generators in the cortex. FOs can be of physiologic origin associated to sensory processing and memory consolidation. In epilepsy, FOs are of pathologic origin and biomarkers of the epileptogenic zone. Seventeen patients with focal epilepsy previously confirmed with identified FOs in scalp electroencephalography (EEG) were evaluated. To handle data deriving from large number of sensors (275 axial gradiometers) we used an automatic detector with high sensitivity. False positives were discarded by two human experts. MSI of the FOs was performed with the wavelet based maximum entropy on the mean method. We found FOs in 11/17 patients, in only one patient the channel with highest FO rate was not concordant with the epileptogenic region and might correspond to physiologic oscillations. MEG FOs rates were very low: 0.02-4.55 per minute. Compared to scalp EEG, detection sensitivity was lower, but the specificity higher in MEG. MSI of FOs showed concordance or partial concordance with proven generators of seizures and epileptiform activity in 10/11 patients. We have validated the proposed framework for the non-invasive study of FOs with MEG. The excellent overall concordance with other clinical gold standard evaluation tools indicates that MEG FOs can provide relevant information to guide implantation for intracranial EEG pre-surgical evaluation and for surgical treatment, and demonstrates the important added value of choosing appropriate FOs detection and source localization methods. PMID:26830767

  12. Recovering Paleo-Records from Antarctic Ice-Cores by Coupling a Continuous Melting Device and Fast Ion Chromatography.

    PubMed

    Severi, Mirko; Becagli, Silvia; Traversi, Rita; Udisti, Roberto

    2015-11-17

    Recently, the increasing interest in the understanding of global climatic changes and on natural processes related to climate yielded the development and improvement of new analytical methods for the analysis of environmental samples. The determination of trace chemical species is a useful tool in paleoclimatology, and the techniques for the analysis of ice cores have evolved during the past few years from laborious measurements on discrete samples to continuous techniques allowing higher temporal resolution, higher sensitivity and, above all, higher throughput. Two fast ion chromatographic (FIC) methods are presented. The first method was able to measure Cl(-), NO3(-) and SO4(2-) in a melter-based continuous flow system separating the three analytes in just 1 min. The second method (called Ultra-FIC) was able to perform a single chromatographic analysis in just 30 s and the resulting sampling resolution was 1.0 cm with a typical melting rate of 4.0 cm min(-1). Both methods combine the accuracy, precision, and low detection limits of ion chromatography with the enhanced speed and high depth resolution of continuous melting systems. Both methods have been tested and validated with the analysis of several hundred meters of different ice cores. In particular, the Ultra-FIC method was used to reconstruct the high-resolution SO4(2-) profile of the last 10,000 years for the EDML ice core, allowing the counting of the annual layers, which represents a key point in dating these kind of natural archives. PMID:26494022

  13. A space-based radio frequency transient event classifier

    SciTech Connect

    Moore, K.R.; Blain, P.C.; Caffrey, M.P.; Franz, R.C.; Henneke, K.M.; Jones, R.G.

    1996-12-31

    The FORTE (Fast On-Orbit Recording of Transient Events) satellite will record RF transients in space. These transients will be classified onboard the spacecraft with an Event Classifier--specialized hardware that performs signal preprocessing and neural network classification. The authors describe the Event Classifier, future directions, and implications for telecommunications satellites. Telecommunication satellites are susceptible to damage from environmental factors such as deep dielectric charging and surface discharges. The event classifier technology the authors are developing is capable of sensing the surface discharges and could be useful for mitigating their effects. In addition, the techniques they are using for processing weak signals in noisy environments are relevant to telecommunications.

  14. Year-long continuous personal exposure to PM 2.5 recorded by a fast responding portable nephelometer

    NASA Astrophysics Data System (ADS)

    Braniš, Martin; Kolomazníková, Jana

    2010-08-01

    Personal exposure to particulate matter of aerodynamic diameter under 2.5 μm (PM 2.5) was monitored using a DustTrak nephelometer. The battery-operated unit, worn by an adult individual for a period of approximately one year, logged integrated average PM 2.5 concentrations over 5 min intervals. A detailed time-activity diary was used to record the experimental subject's movement and the microenvironments visited. Altogether 239 days covering all the months (except April) were available for the analysis. In total, 60 463 acceptable 5-min averages were obtained. The dataset was divided into 7 indoor and 4 outdoor microenvironments. Of the total time, 84% was spent indoors, 10.9% outdoors and 5.1% in transport. The indoor 5-min PM 2.5 average was higher (55.7 μg m -3) than the outdoor value (49.8 μg m -3). The highest 5-min PM 2.5 average concentration was detected in restaurant microenvironments (1103 μg m -3), the second highest 5-min average concentration was recorded in indoor spaces heated by stoves burning solid fuels (420 μg m -3). The lowest 5-min mean aerosol concentrations were detected outdoors in rural/natural environments (25 μg m -3) and indoors at the monitored person's home (36 μg m -3). Outdoor and indoor concentrations of PM 2.5 measured by the nephelometer at home and during movement in the vicinity of the experimental subject's home were compared with those of the nearest fixed-site monitor of the national air quality monitoring network. The high correlation coefficient (0.78) between the personal and fixed-site monitor aerosol concentrations suggested that fixed-site monitor data can be used as proxies for personal exposure in residential and some other microenvironments. Collocated measurements with a reference method (β-attenuation) showed a non-linear systematic bias of the light-scattering method, limiting the use of direct concentration readings for exact exposure analysis.

  15. The roles of production and preservation during Oceanic Anoxic Event III: A multi-proxy record from the Western Interior Seaway

    NASA Astrophysics Data System (ADS)

    Tessin, A. C.; Hendy, I. L.; Sheldon, N. D.

    2013-12-01

    Cretaceous marine deposits are characterized by periods of enhanced organic carbon burial, known as Oceanic Anoxic Events (OAEs). A major unresolved debate about OAEs is whether changes in preservation or production are responsible for organic carbon burial. To address this question it is important to determine the relative roles of reducing bottom water conditions and surface water primary productivity at the onset of the event. Here we examine the Coniacian-Santonian event (OAE III) using high-resolution major element and trace metal records of the Niobrara Formation recovered in the USGS #1 Portland core from Cañon City Basin, Colorado. Preliminary results of redox sensitive trace metals (Re, Mo, U) and trace metals associated with organic matter (Cd, Ag) indicate that both bottom water suboxia and elevated primary productivity played a role in organic carbon burial during OAE III. The onset of organic carbon accumulation is characterized by two distinct periods of redox-sensitive trace metal enrichments indicating that initial carbon burial is associated with the development of bottom water suboxia. The second enrichment is followed by a shift in trace metal baseline values. Elevated concentrations of Cd and Ag without corresponding major enrichments in Re, Mo and U indicate the increased influence of high primary productivity. We compare trace metals records with bulk organic analyses (%TOC, C:N ratios, and organic carbon isotopes) to further elucidate the relationship between organic carbon accumulation, primary productivity, and bottom water oxygenation. Results from the Portland core are also compared to nearby cores in Colorado and Kansas to evaluate spatial variability throughout the carbon burial event, to examine differences between marginal and open seaway records, and to assess the role of proximity to terrestrial input.

  16. An innovative approach to medical control: semiautomatic defibrillators with solid-state memory modules for recording cardiac arrest events.

    PubMed

    Cummins, R O; Austin, D; Graves, J R; Hambly, C

    1988-08-01

    We evaluated the use of microprocessor-based memory modules incorporated into automatic external defibrillators. These solid-state modules store information about each clinical use, including selected segments of the ECG rhythm and notations on defibrillator operation. A playback unit provides annotated printouts of the recorded information. The purpose of our evaluation was to determine whether this memory module could adequately support medical control "run-reviews" when compared with dualfunction (voice and ECG) tape recordings. A total of 41 resuscitation attempts by emergency medical technicians trained to defibrillate (EMT-Ds) were evaluated in five preselected performance areas: defibrillation skills, command and communication at the scene, patient assessment and support, safety, and speed. When performance was reviewed using the tape recordings, the average EMT-D performance score was 16.2 (maximum, 20); when reviewed using the printouts from the medical control modules, the average score, 7.2, was significantly lower (P less than .01). The lower scores with the medical control module occurred because not all five areas of skill could be evaluated adequately by the memory module approach. Assessment of the areas of communication/command at the scene, patient assessment/support, and safety required verbal tape recordings. The medical control module appeared superior to the tape recordings at providing a quick, convenient, and accurate evaluation of rhythm assessment, shock decisions, time intervals, and defibrillator performance. They make several features of medical control review easier and more convenient, and may encourage implementation of early defibrillation programs. We conclude, however, that medical control modules cannot replace on-scene tape recordings for adequate medical control of EMT-D programs. PMID:3394986

  17. Fast analysis of terbutaline in pharmaceuticals using multi-walled nanotubes modified electrodes from recordable compact disc.

    PubMed

    Felix, Fabiana S; Daniel, Daniela; Matos, Jivaldo R; Lucio do Lago, Claudimir; Angnes, Lúcio

    2016-07-20

    In this study, homemade disposable gold electrodes made from recordable compact disks were modified with carbon nanotubes for amperometric quantification of terbutaline sulfate in pharmaceutical products. A flow cell using an impingent jet of solution on the electrode surface was build and used for amperometric detection, and a series of experiments were carried out to find the best experimental conditions for the new electrode in a specially designed cell. A linear response for terbutaline was obtained in the range from 3.0 × 10(-6) to 5.0 × 10(-4) mol L(-1) (at 0.63 V vs. Ag/AgCl). The limits of detection and quantification were calculated as 5.8 × 10(-7) mol L(-1) (S/N = 3) and 1.9 × 10(-6) mol L(-1) (S/N = 10), respectively. A frequency of 30 injections h(-1) was attained. The proposed method was successfully applied to the analyses of commercial syrup samples, and all results were in good agreement with those obtained by using high performance liquid chromatography and capillary electrophoresis-tandem mass spectrometry. PMID:27251854

  18. Carbon cycle perturbations recorded by δ13C of bulk organic matter: the Carnian Pluvial Event in the Dolomites, northern Italy

    NASA Astrophysics Data System (ADS)

    Preto, Nereo; Breda, Anna; Dal Corso, Jacopo; Rigo, Manuel; Roghi, Guido; Spötl, Christoph

    2015-04-01

    A period of increased rainfall occurred in the Carnian (Late Triassic), known as Carnian Pluvial Event (CPE), which is evidenced by major lithological changes in continental and marine successions at tropical latitudes. Increased continental weathering and erosion led to the supply of large amounts of siliciclastics into the marginal basins of the Tethys. Seawater anoxia is also observed locally in semi-restricted basins. Simultaneously, microbial factories on high-relief carbonate platforms were replaced by metazoan factories, forming low-relief carbonate ramps and mixed low-gradient shelves. This environmental change has been shown to be closely associated with a negative carbon isotope excursion. A negative δ13C shift is recorded by bulk organic matter in the Milieres section (central Dolomites) and parallels a coeval excursion in carbon-isotope records of higher plant and marine algal biomarker, thus testifying a global change in the isotopic composition of carbon dioxide in the atmosphere and of dissolved inorganic carbon (DIC) in the ocean. This isotopic excursion was identified in organic carbon records throughout the western Tethys, but so far could not be reproduced convincingly using carbon isotope records from carbonate. A long carbon isotope record was produced from bulk organic matter of the early to late Carnian Milieres - Dibona section in the Dolomites, northern Italy. Carbon isotope analyses of carbonate (limestone and dolomite) were also obtained. This new carbon isotope record illustrates the structure of this complex carbon cycle perturbation related to the CPE. But while sharp carbon isotope oscillations are evident in the bulk organic carbon record, there is no evidence of a similar pattern in carbonate record. It can be shown that the carbon isotope record of carbonates is influenced by fractionation and diagenetic processes that completely obliterated the original δ13C signal. We conclude that the Carnian carbonates of the Dolomites do not

  19. Pulse oximetry recorded from the Phone Oximeter for detection of obstructive sleep apnea events with and without oxygen desaturation in children.

    PubMed

    Garde, Ainara; Dehkordi, Parastoo; Wensley, David; Ansermino, J Mark; Dumont, Guy A

    2015-08-01

    Obstructive sleep apnea (OSA) disrupts normal ventilation during sleep and can lead to serious health problems in children if left untreated. Polysomnography, the gold standard for OSA diagnosis, is resource intensive and requires a specialized laboratory. Thus, we proposed to use the Phone Oximeter™, a portable device integrating pulse oximetry with a smartphone, to detect OSA events. As a proportion of OSA events occur without oxygen desaturation (defined as SpO2 decreases ≥ 3%), we suggest combining SpO2 and pulse rate variability (PRV) analysis to identify all OSA events and provide a more detailed sleep analysis. We recruited 160 children and recorded pulse oximetry consisting of SpO2 and plethysmography (PPG) using the Phone Oximeter™, alongside standard polysomnography. A sleep technician visually scored all OSA events with and without oxygen desaturation from polysomnography. We divided pulse oximetry signals into 1-min signal segments and extracted several features from SpO2 and PPG analysis in the time and frequency domain. Segments with OSA, especially the ones with oxygen desaturation, presented greater SpO2 variability and modulation reflected in the spectral domain than segments without OSA. Segments with OSA also showed higher heart rate and sympathetic activity through the PRV analysis relative to segments without OSA. PRV analysis was more sensitive than SpO2 analysis for identification of OSA events without oxygen desaturation. Combining SpO2 and PRV analysis enhanced OSA event detection through a multiple logistic regression model. The area under the ROC curve increased from 81% to 87%. Thus, the Phone Oximeter™ might be useful to monitor sleep and identify OSA events with and without oxygen desaturation at home. PMID:26738074

  20. Pulse oximetry recorded from the Phone Oximeter for detection of obstructive sleep apnea events with and without oxygen desaturation in children.

    PubMed

    Garde, Ainara; Dehkordi, Parastoo; Wensley, David; Ansermino, J Mark; Dumont, Guy A

    2015-01-01

    Obstructive sleep apnea (OSA) disrupts normal ventilation during sleep and can lead to serious health problems in children if left untreated. Polysomnography, the gold standard for OSA diagnosis, is resource intensive and requires a specialized laboratory. Thus, we proposed to use the Phone Oximeter™, a portable device integrating pulse oximetry with a smartphone, to detect OSA events. As a proportion of OSA events occur without oxygen desaturation (defined as SpO2 decreases ≥ 3%), we suggest combining SpO2 and pulse rate variability (PRV) analysis to identify all OSA events and provide a more detailed sleep analysis. We recruited 160 children and recorded pulse oximetry consisting of SpO2 and plethysmography (PPG) using the Phone Oximeter™, alongside standard polysomnography. A sleep technician visually scored all OSA events with and without oxygen desaturation from polysomnography. We divided pulse oximetry signals into 1-min signal segments and extracted several features from SpO2 and PPG analysis in the time and frequency domain. Segments with OSA, especially the ones with oxygen desaturation, presented greater SpO2 variability and modulation reflected in the spectral domain than segments without OSA. Segments with OSA also showed higher heart rate and sympathetic activity through the PRV analysis relative to segments without OSA. PRV analysis was more sensitive than SpO2 analysis for identification of OSA events without oxygen desaturation. Combining SpO2 and PRV analysis enhanced OSA event detection through a multiple logistic regression model. The area under the ROC curve increased from 81% to 87%. Thus, the Phone Oximeter™ might be useful to monitor sleep and identify OSA events with and without oxygen desaturation at home.

  1. Mid Holocene Evidence of High Energy Events in the Geological Record: Sedimentary Deposits from Cauvery Delta Coast, SE Coast of India.

    NASA Astrophysics Data System (ADS)

    Karthikeyan, A.; Seshachalam, S.; Jonathan, M. P.; Roy, P. D.

    2014-12-01

    The Cauvery Basin is one of the important sedimentary basins of southern India and provides information on geological processes since the Cretaceous. Most of the studies in the basin have been carried out on the sediments representing Cretaceous with less emphasis on the Quaternary period with marine high energy event. In the present study, we present the sedimentological and micro fauna assemblages in the 150 cm long trench from the Kameshwaram village, Nagapattinam District, South East Coast of India, in order to reconstruct the past event. OSL and Carbon dating of sand layer sediments from the Cauvery Basin provide the first proxy-record of marine event from the region over the Mid Holocene. A multi proxy approach using trench sediments from Cauvery Delta Coast, East coast of Tamil Nadu provides a high resolution record of high energy event. The dating of the event layer indicates 6 and 8 kyrs also below the layer shell layer was preserved, the radio carbon date of the shell layer was 6545 BC. A combination of sedimentological parameters of grain size, sorting, geochemical analysis (XRF) of Fe, Mn, Ti, Cr, Cu, Ni, Sr, Zr and foraminifera species like Ammonia beccarri, Ammonia dentate and Asterorotalia trispinosa were identified. The sediment layers have thinning-up sequences and it starts from 130 cm to the bottom of the layer 150 cm which included shell debris, and rip-up clasts. In addition, characteristic variations in elemental content at the bottom units of Zr, Ti, Ca is showing higher concentration, which is an indicator of high-energy depositional event often associated with an increase in Ti (2.08 % to 16.016 %) and Sr (116 ppm to 275 ppm). Ca on the other hand suggests a marine influence and Fe, Mn, Cr, Ni values are showing lower concentration indicating that the high marine energy event had inundated the Nagapattinam district in SE coast of India. Based on the multiproxy evidences, we conclude that this could be a major marine event during the Mid

  2. An event-based comparison of two types of automated-recording, weighing bucket rain gauges 1890

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multi-year, multi-gage comparison of two types of automated-recording weighing-bucket raingages was conducted using precipitation data collected at the United States Department of Agriculture, Agricultural Research Service’s Walnut Gulch Experimental Watershed in Southeast Arizona. The compariso...

  3. Using the significant dust deposition event on the glaciers of Mt. Elbrus, Caucasus Mountains, Russia on 5 May 2009 to develop a method for dating and provenancing of desert dust events recorded in snow pack

    NASA Astrophysics Data System (ADS)

    Shahgedanova, M.; Kutuzov, S.; White, K.; Nosenko, G.

    2012-09-01

    A significant desert dust deposition event occurred on Mt. Elbrus, Caucasus Mountains, Russia on 5 May 2009, where the deposited dust later appeared as a brown layer in the snow pack. An examination of dust transportation history and analysis of chemical and physical properties of the deposited dust were used to develop a new approach for high-resolution provenancing of dust deposition events recorded in snow pack using multiple independent techniques. A combination of SEVIRI red-green-blue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived with HYSPLIT model and analysis of meteorological data enabled identification of dust source regions with high temporal (hours) and spatial (ca. 100 km) resolution. Dust, deposited on 5 May 2009, originated in the foothills of the Djebel Akhdar in eastern Libya where dust sources were activated by the intrusion of cold air from the Mediterranean Sea and Saharan low pressure system and transported to the Caucasus along the eastern Mediterranean coast, Syria and Turkey. Particles with an average diameter below 8 μm accounted for 90% of the measured particles in the sample with a mean of 3.58 μm, median 2.48 μm and the dominant mode of 0.60 μm. The chemical signature of this long-travelled dust was significantly different from the locally-produced dust and close to that of soils collected in a palaeolake in the source region, in concentrations of hematite and oxides of aluminium, manganese, and magnesium. Potential addition of dust from a secondary source in northern Mesopotamia introduced uncertainty in the provenancing of dust from this event. Nevertheless, the approach adopted here enables other dust horizons in the snowpack to be linked to specific dust transport events recorded in remote sensing and meteorological data archives.

  4. Using the significant dust deposition event on the glaciers of Mt.~Elbrus, Caucasus Mountains, Russia on 5 May 2009 to develop a method for dating and "provenancing" of desert dust events recorded in snow pack

    NASA Astrophysics Data System (ADS)

    Shahgedanova, M.; Kutuzov, S.; White, K. H.; Nosenko, G.

    2013-02-01

    A significant desert dust deposition event occurred on Mt. Elbrus, Caucasus Mountains, Russia on 5 May 2009, where the deposited dust later appeared as a brown layer in the snow pack. An examination of dust transportation history and analysis of chemical and physical properties of the deposited dust were used to develop a new approach for high-resolution "provenancing" of dust deposition events recorded in snow pack using multiple independent techniques. A combination of SEVIRI red-green-blue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived with HYSPLIT model and analysis of meteorological data enabled identification of dust source regions with high temporal (hours) and spatial (ca. 100 km) resolution. Dust, deposited on 5 May 2009, originated in the foothills of the Djebel Akhdar in eastern Libya where dust sources were activated by the intrusion of cold air from the Mediterranean Sea and Saharan low pressure system and transported to the Caucasus along the eastern Mediterranean coast, Syria and Turkey. Particles with an average diameter below 8 μm accounted for 90% of the measured particles in the sample with a mean of 3.58 μm, median 2.48 μm. The chemical signature of this long-travelled dust was significantly different from the locally-produced dust and close to that of soils collected in a palaeolake in the source region, in concentrations of hematite. Potential addition of dust from a secondary source in northern Mesopotamia introduced uncertainty in the "provenancing" of dust from this event. Nevertheless, the approach adopted here enables other dust horizons in the snowpack to be linked to specific dust transport events recorded in remote sensing and meteorological data archives.

  5. The record of Tethyan planktonic foraminifera at the early Paleogene hyperthermal events and Middle Eocene Climatic Optimum in northeastern Italy: are they comparable?

    NASA Astrophysics Data System (ADS)

    Luciani, Valeria; Giusberti, Luca; Agnini, Claudia; Fornaciari, Eliana; Rio, Domenico

    2010-05-01

    The early Paleogene is one of the more climatically and evolutionary dynamic periods in the Earth history that records a pronounced warming trend peaking in the Early Eocene, and a successive composite transition towards the modern icehouse world. Ever increasingly scientific attention is dedicated to definitely comprehend timing, nature and characters of the complex, non-linear evolution of the Paleogene climate. Several complete and expanded Paleogene successions (Forada, Possagno, Alano, Farra), with a sound magneto-biochronostratigraphic and stable isotope record crop out in the Venetian Southern Alps (Northeast Italy). Recent studies (Giusberti et. al., 2007; Luciani et al., 2007; Agnini et al., 2008) and unpublished data document the presence in these section of the main short-lived warming events (hyperthermals) of the Eocene (Paleocene-Eocene Thermal Maximum, PETM, ca 55 Ma, Eocene Layer of Mysterious Origin (ELMO, ca 53,6 Ma), X-event (ca 52.5 Ma), of the Early Eocene Climatic Optimum (EECO, ca 50-52 Ma) and of the Middle Eocene Climatic Optimum (MECO, ca 40 Ma; Zachos et al., 2001. 2008). All these events are typified by marked negative shifts in δ13C curves that correspond to carbonate decrease related to rise of the carbonate compensation depth in turn induced by large introduction in the ocean-atmosphere system of CO2. Common features to the warming events are pronounced and complex changes in planktonic foraminiferal assemblages, indicating strong environmental perturbations that perfectly parallel the variations of the stable isotope curves in all the examined events. These strict correspondences indicate close cause-effect relationships between changes in environmental conditions and modifications of the assemblages. Our analysis shows that the most striking variations are recorded by the PETM and MECO assemblages that reflect highly perturbed environments. The ELMO, X-event and EECO exhibit planktic foraminiferal responses that are similar to

  6. A 50,000-year record of climate oscillations from Florida and its temporal correlation with the Heinrich events

    SciTech Connect

    Grimm, E.C. ); Jacobson, G.L. Jr.; Maasch, K.A. ); Watts, W.A. ); Hansen, B.C.S. )

    1993-07-09

    Oscillations of Pinus (pine) pollen in a 50,000-year sequence from Lake Tulane, Florida, indicate that there were major vegetation shifts during the last glacial cycle. Episodes of abundant Pinus populations indicate a climate that was more wet than intervening phases dominated by Quercus (oak) and Ambrosia-type (ragweed and marsh-elder). The Pinus episodes seem to be temporally correlated with the North Atlantic Heinrich events, which were massive, periodic advances of ice streams from the eastern margin of the Laurentide Ice Sheet. Possible links between the Tulane Pinus and Heinrich events include hemispheric cooling, the influences of Mississippi meltwater on sea-surface temperatures in the Gulf of Mexico, and the effects of North Atlantic thermohaline circulation on currents in the Gulf. 33 refs., 4 figs., 1 tab.

  7. A 50,000-year record of climate oscillations from Florida and its temporal correlation with the heinrich events.

    PubMed

    Grimm, E C; Jacobson, G L; Watts, W A; Hansen, B C; Maasch, K A

    1993-07-01

    Oscillations of Pinus (pine) pollen in a 50,000-year sequence from Lake Tulane, Florida, indicate that there were major vegetation shifts during the last glacial cycle. Episodes of abundant Pinus populations indicate a climate that was more wet than intervening phases dominated by Quercus (oak) and Ambrosia-type (ragweed and marsh-elder). The Pinus episodes seem to be temporally correlated with the North Atlantic Heinrich events, which were massive, periodic advances of ice streams from the eastern margin of the Laurentide Ice Sheet. Possible links between the Tulane Pinus and Heinrich events include hemispheric cooling, the influences of Mississippi meltwater on sea-surface temperatures in the Gulf of Mexico, and the effects of North Atlantic thermohaline circulation on currents in the Gulf.

  8. A 50,000-year record of climate oscillations from Florida and its temporal correlation with the heinrich events.

    PubMed

    Grimm, E C; Jacobson, G L; Watts, W A; Hansen, B C; Maasch, K A

    1993-07-01

    Oscillations of Pinus (pine) pollen in a 50,000-year sequence from Lake Tulane, Florida, indicate that there were major vegetation shifts during the last glacial cycle. Episodes of abundant Pinus populations indicate a climate that was more wet than intervening phases dominated by Quercus (oak) and Ambrosia-type (ragweed and marsh-elder). The Pinus episodes seem to be temporally correlated with the North Atlantic Heinrich events, which were massive, periodic advances of ice streams from the eastern margin of the Laurentide Ice Sheet. Possible links between the Tulane Pinus and Heinrich events include hemispheric cooling, the influences of Mississippi meltwater on sea-surface temperatures in the Gulf of Mexico, and the effects of North Atlantic thermohaline circulation on currents in the Gulf. PMID:17829277

  9. A methodology for interactive mining and visual analysis of clinical event patterns using electronic health record data.

    PubMed

    Gotz, David; Wang, Fei; Perer, Adam

    2014-04-01

    Patients' medical conditions often evolve in complex and seemingly unpredictable ways. Even within a relatively narrow and well-defined episode of care, variations between patients in both their progression and eventual outcome can be dramatic. Understanding the patterns of events observed within a population that most correlate with differences in outcome is therefore an important task in many types of studies using retrospective electronic health data. In this paper, we present a method for interactive pattern mining and analysis that supports ad hoc visual exploration of patterns mined from retrospective clinical patient data. Our approach combines (1) visual query capabilities to interactively specify episode definitions, (2) pattern mining techniques to help discover important intermediate events within an episode, and (3) interactive visualization techniques that help uncover event patterns that most impact outcome and how those associations change over time. In addition to presenting our methodology, we describe a prototype implementation and present use cases highlighting the types of insights or hypotheses that our approach can help uncover. PMID:24486355

  10. A methodology for interactive mining and visual analysis of clinical event patterns using electronic health record data.

    PubMed

    Gotz, David; Wang, Fei; Perer, Adam

    2014-04-01

    Patients' medical conditions often evolve in complex and seemingly unpredictable ways. Even within a relatively narrow and well-defined episode of care, variations between patients in both their progression and eventual outcome can be dramatic. Understanding the patterns of events observed within a population that most correlate with differences in outcome is therefore an important task in many types of studies using retrospective electronic health data. In this paper, we present a method for interactive pattern mining and analysis that supports ad hoc visual exploration of patterns mined from retrospective clinical patient data. Our approach combines (1) visual query capabilities to interactively specify episode definitions, (2) pattern mining techniques to help discover important intermediate events within an episode, and (3) interactive visualization techniques that help uncover event patterns that most impact outcome and how those associations change over time. In addition to presenting our methodology, we describe a prototype implementation and present use cases highlighting the types of insights or hypotheses that our approach can help uncover.

  11. Event-related potentials recorded from the cingulate gyrus during attentional tasks: a study in patients with implanted electrodes.

    PubMed

    Turak, Baris; Louvel, Jacques; Buser, Pierre; Lamarche, Michel

    2002-01-01

    Recent neuroimaging data suggests that the cingulate gyrus is involved in a variety of cognitive tasks. In this study sensory field potentials were directly recorded from the cingulate gyrus in order to investigate its implication in attentional processes associated or not with a motor task. Evoked potentials recordings were performed in 29 epileptic patients with multilead electrodes implanted for presurgical evaluation, who agreed to participate in an experimental protocol consisting of a series of paradigms designed using a warning auditory tone, two distinct visual patterns and various attentional, memory, motor and decisional tasks. Our data shows that evoked potentials could be recorded from various parts of the cingulate gyrus. The inclusion of an instruction in the experimental paradigm resulted in an increase in the amplitude of the late, intrinsic component of the visual evoked potential culminating at about 450 ms. Several variations of response patterns across individuals were identified. We conclude that the cingulate gyrus appears to be a multimodal area involved in several types of cognitive activity, including attention. Variations in response patterns are probably related to differences in the strategy adopted by each subject when faced with a particular cognitive task.

  12. Problems with identifying the 8200-year cold event in terrestrial records of the Atlantic seaboard: a case study from Dooagh, Achill Island, Ireland

    NASA Astrophysics Data System (ADS)

    Head, Katie; Turney, Chris S. M.; Pilcher, Jon R.; Palmer, J. G.; Baillie, M. G. L.

    2007-01-01

    The Northern Hemisphere cooling event 8200 years ago is believed to represent the last known major freshwater pulse into the North Atlantic as a result of the final collapse of the North American Laurentide ice sheet. This pulse of water is generally believed to have occurred independently of orbital variations and provides an analogue for predicted increases in high-latitude precipitation and ice melt as a result of anthropogenically driven future climate change. The precise timing, duration and magnitude of this event, however, are uncertain, with suggestions that the 100-yr meltwater cooling formed part of a longer-term cold period in the early Holocene. Here we undertook a multiproxy, high-resolution investigation of a peat sequence at Dooagh, Achill Island, on the west coast of Ireland, to determine whether the 8200-year cold event impacted upon the terrestrial vegetation immediately downwind of the proposed changes in the North Atlantic. We find clear evidence for an oscillation in the early Holocene using various measures of pollen, indicating a disruption in the vegetation leading to a grassland-dominated landscape, most probably driven by changes in precipitation rather than temperature. Radiocarbon dating was extremely problematic, however, with bulk peat samples systematically too young for the North Atlantic event, suggesting significant contamination from downward root penetration. The sustained disruption to vegetation over hundreds of years at Dooagh indicates the landscape was impacted by a long-term cooling event in the early Holocene, and not the single century length 8200-year meltwater event proposed in many other records in the North Atlantic region. Copyright

  13. A software oscilloscope for DOS computers with an integrated remote control for a video tape recorder. The assignment of acoustic events to behavioural observations.

    PubMed

    Höller, P

    1995-12-01

    With only a little knowledge of programming IBM compatible computers in Basic, it is possible to create a digital software oscilloscope with sampling rates up to 17 kHz (depending on the CPU- and bus-speed). The only additional hardware requirement is a common sound card compatible with the Soundblaster. The system presented in this paper is built to analyse the direction a flying bat is facing during sound emission. For this reason the system works with some additional hardware devices, in order to monitor video sequences at the computer screen, overlaid by an online oscillogram. Using an RS232-interface for a Panasonic video tape recorder both the oscillogram and the video tape recorder can be controlled simultaneously and moreover be analysed frame by frame. Not only acoustical events, but also APs, myograms, EEGs and other physiological data can be digitized and analysed in combination with the behavioural data of an experimental subject.

  14. Statistical study of ELF/VLF emissions recorded by a low-altitude satellite during seismic events

    SciTech Connect

    Parrot, M.

    1994-12-01

    The author reports a study of correlations between 325 earthquakes registering M{sub s}>5, and frequency filtered data observed by the low altitude satellite AUREOL 3 within a 24 hour window around the event. Data is sorted by time difference, difference in longitude, and difference in invariant latitude, between the satellite location and the epicenter. It is found that for the averaged data, the strongest signals are observed when the longitudinal differences are less than 10{degrees}, independent of latitude. The collected data was not continuous in nature, and therefore limits the nature of the statistical study which can be done.

  15. Late Pleistocene and Holocene palaeoflood events recorded by slackwater deposits in the upper Hanjiang River valley, China

    NASA Astrophysics Data System (ADS)

    Liu, Tao; Huang, Chun Chang; Pang, Jiangli; Zha, Xiaochun; Zhou, Yali; Zhang, Yuzhu; Ji, Lin

    2015-10-01

    Slackwater palaeoflood deposits (SWDs) were identified in a bedrock gorge in the upper reaches of the Hanjiang River of central China. The Hanjiang River is the longest tributary of the Yangtze River, one of the most flood-prone rivers in China, and the main source of water for the South-to-North Water Transfer Project (SNWTP). Three main loess-soil profiles with late Pleistocene and Holocene palaeoflood SWD bedsets were found. Palaeoflood SWDs identified interbedded in the loess-soil sequence of late Pleistocene and Holocene age within the cliff riverbanks were studied by field observations and laboratory analysis, including particle-size distribution and Optically Stimulated Luminescence (OSL) dating. At least eight extreme flood events documented by palaeoflood SWDs occurred in the Wufeng reaches of the upper Hanjiang River. The discharge estimation associated with palaeoflood SWDs, indicates that the minimum flood peak discharges of these flood episodes range from 42,220 to 63,400 m3/s. The SWDs were OSL dated to between 12,600-12,400, 4200-4000, 3200-2800 and 1900-1700 a BP and these dates were corroborated with pottery remains retrieved from the profiles and dated by archaeological methods. These periods of increased flood magnitude coincide with contemporaneous global climatic events dated to 12,500, 4200, 3100 and 1900 a BP worldwide. These findings are of great significance in understanding the interactions between hydrological systems and climatic change in monsoonal zones.

  16. Biomarkers from Huronian oil-bearing fluid inclusions: An uncontaminated record of life before the Great Oxidation Event

    NASA Astrophysics Data System (ADS)

    Dutkiewicz, Adriana; Volk, Herbert; George, Simon C.; Ridley, John; Buick, Roger

    2006-06-01

    We report detailed molecular geochemistry of oil-bearing fluid inclusions from a ca. 2.45 Ga fluvial metaconglomerate of the Matinenda Formation at Elliot Lake, Canada. The oil, most likely derived from the conformably overlying McKim Formation, was trapped in quartz and feldspar during diagenesis and early metamorphism of the host rock, probably before ca. 2.2 Ga. The presence of abundant biomarkers for cyanobacteria and eukaryotes derived from and trapped in rocks deposited before the Great Oxidation Event is consistent with an earlier evolution of oxygenic photosynthesis than previously thought and suggests that some aquatic settings had become sufficiently oxygenated for sterol biosynthesis by this time. It also implies that eukaryotes survived several extreme climatic events, including the Paleoproterozoic “snowball Earth” glaciations. The extraction of biomarker molecules from Paleoproterozoic oil-bearing fluid inclusions thus establishes a new method, using low detection limits and system blank levels, to trace evolution of life through Earth's early history that avoids the potential contamination problems affecting shale-hosted hydrocarbons.

  17. Change in Mediterranean Hydrologic Cycle at Time of Heinrich Events From a High Resolution Multiproxy Record of the Last 50 kyr

    NASA Astrophysics Data System (ADS)

    Bout-Roumazeilles, V.; Combourieu Nebout, N.; Peyron, O.; Dormoy, I.

    2008-12-01

    Clay mineralogy, pollen record and pollen-based reconstructions were performed over the last climatic cycle on the Site ODP 976 (Alboran Sea, Western Mediterranean). These proxies show that several droughts occurred during the past 50 kyr. Enhanced contribution of wind-blown palygorskite and development of the semi-arid vegetation (Artemisia rich) occurs during the North Atlantic Cold climatic events (Heinrich events). The peculiar clay mineral association and the presence of Argania pollen grains pinpoint Western Morocco as a major source for wind-blown particles during the Heinrich events. Clay mineral and pollen associations indicate the development of semi-desert environment and the intensification of winds favoring dust erosion and transport from Sahara toward the Alboran Sea during the North Atlantic Heinrich events. Quantitative climate reconstructions performed on the ODP976 pollen record have yielded the reconstruction of ombrothermic diagrams for past key periods. They reveal that annual precipitations regime in the west Mediterranean area were rather different during Heinrich events than today with drastic drought during the whole year. As a comparison, the reconstructed Holocene and stadials annual climatic cycles are very similar to present-day distribution, with dry conditions restricted to summertime. During these cold climatic events, the drastic fall in both precipitations and temperatures suggest cold and arid continental conditions in the West Mediterranean area. These regions were suffering from reduced precipitations not only during winter but also during spring and fall usually experiencing wet conditions. Such a major modification, with repetitive cold and dry-conditions in both winter and spring, should have deeply affected the development of temperate forest -sensitive to precipitation amount- and of the Mediterranean forest which lives under warm-dry summer and mild-humid winter conditions. These clay- and pollen-based reconstructions

  18. Record-low primary productivity and high plant damage in the Nordic Arctic Region in 2012 caused by multiple weather events and pest outbreaks

    NASA Astrophysics Data System (ADS)

    Bjerke, Jarle W.; Rune Karlsen, Stein; Arild Høgda, Kjell; Malnes, Eirik; Jepsen, Jane U.; Lovibond, Sarah; Vikhamar-Schuler, Dagrun; Tømmervik, Hans

    2014-08-01

    The release of cold temperature constraints on photosynthesis has led to increased productivity (greening) in significant parts (32-39%) of the Arctic, but much of the Arctic shows stable (57-64%) or reduced productivity (browning, <4%). Summer drought and wildfires are the best-documented drivers causing browning of continental areas, but factors dampening the greening effect of more maritime regions have remained elusive. Here we show how multiple anomalous weather events severely affected the terrestrial productivity during one water year (October 2011-September 2012) in a maritime region north of the Arctic Circle, the Nordic Arctic Region, and contributed to the lowest mean vegetation greenness (normalized difference vegetation index) recorded this century. Procedures for field data sampling were designed during or shortly after the events in order to assess both the variability in effects and the maximum effects of the stressors. Outbreaks of insect and fungal pests also contributed to low greenness. Vegetation greenness in 2012 was 6.8% lower than the 2000-11 average and 58% lower in the worst affected areas that were under multiple stressors. These results indicate the importance of events (some being mostly neglected in climate change effect studies and monitoring) for primary productivity in a high-latitude maritime region, and highlight the importance of monitoring plant damage in the field and including frequencies of stress events in models of carbon economy and ecosystem change in the Arctic. Fourteen weather events and anomalies and 32 hypothesized impacts on plant productivity are summarized as an aid for directing future research.

  19. Sea level response to ENSO along the central California coast: How the 1997-1998 event compares with the historic record

    USGS Publications Warehouse

    Ryan, H.F.; Noble, M.

    2002-01-01

    Long-term monthly sea level and sea surface temperature (SST) anomalies from central California show that during winter months, positive anomalies are associated with El Nin??o events and the negative ones with La Nin??a events. There is no significant impact on monthly mean anomalies associated with Pacific decadal oscillations, although there is a tendency for more extreme events and greater variance during positive decadal oscillations. The very strong 1997-1998 El Nin??o was analyzed with respect to the long-term historic record to assess the forcing mechanisms for sea level and SST. Beginning in the spring of 1997, we observed several long-period (> 30days) fluctuations in daily sea level with amplitudes of over 10 cm at San Francisco, California. Fluctuations of poleward long-period alongshore wind stress anomalies (AWSA) are coherent with the sea level anomalies. However, the wind stress cannot entirely account for the observed sea level signals. The sea level fluctuations are also correlated with sea level fluctuations observed further south at Los Angeles and Tumaco, Columbia, which showed a poleward phase propagation of the sea level signal. We suggest that the sea level fluctuations were, to a greater degree, forced by the passage of remotely generated and coastally trapped waves that were generated along the equator and propagated to the north along the west coast of North America. However, both local and remote AWSA can significantly modulate the sea level signals. The arrival of coastally trapped waves began in the spring of 1997, which is earlier than previous strong El Nin??o events such as the 1982-1983 event. Published by Elsevier Science Ltd.

  20. Extreme events in the sedimentary record of maar Lake Pavin: Implications for natural hazards assessment in the French Massif Central

    NASA Astrophysics Data System (ADS)

    Chassiot, Léo; Chapron, Emmanuel; Di Giovanni, Christian; Albéric, Patrick; Lajeunesse, Patrick; Lehours, Anne-Catherine; Meybeck, Michel

    2016-06-01

    A set of sedimentary cores, high resolution swath bathymetry and subbottom profiler data provides new insights on sedimentary processes in meromictic maar Lake Pavin, France. Three sedimentary environments (i.e., littoral, plateau and basin) have been identified in the lake from sediment composition using bulk organic geochemistry and the analysis of hydroacoustic images. Various forms of rapidly deposited layers (RDLs) have been identified and radiocarbon dated. An up to date stratigraphy of sedimentary events matching coeval RDLs across the lake is presented and illustrates a wide range of natural hazards linked to Lake Pavin during the last 2000 years. In AD 600, a sudden lake outburst triggered a slump deposit along with a 9 m lake-level drop that drove shifts in sedimentary organic matter composition. Outside the lake, outburst flood deposits have been described downstream and provide sedimentary evidence for this event. The lake-level drop also favored the generation of gravity reworking processes, as shown by (1) a regional earthquake-triggered large slope failure on the plateau connected to a mass-wasting deposit in the basin dated to AD 1300, and (2) a succession of turbidites in AD 1825 and AD 1860 contemporaneous to two historic earthquakes, suggesting that this lake is sensitive to earthquakes with a minimum epicentral intensity of V. Finally, past observations of lake water color changes in AD 1783 and AD 1936, similar to reports in other meromictic lakes, match iron-rich deposits identified in maar lake sediments and suggest that Lake Pavin could have undergone limnic eruptions.

  1. On-line image analysis of the stromboli volcanic activity recorded by the surveillance camera helps the forecasting of the major eruptive events.

    NASA Astrophysics Data System (ADS)

    Cristaldi, A.; Coltelli, M.; Mangiagli, S.; Pecora, E.

    2003-04-01

    The typical activity of Stromboli consists of intermittent mild explosions lasting a few seconds, which take place at different vents and at variable intervals, the most common time interval being 10-20 minutes. However, the routine activity can be interrupted by more violent, paroxysmal explosions, that eject m-sized scoriaceous bombs and lava blocks to a distance of several hundreds of meters from the craters, endangering the numerous tourists that watch the spectacular activity from the volcano's summit located about two hundreds meters from the active vents. On average, 1-2 paroxysmal explosions occurred per year over the past century, but this statistic may be underestimated in absence of continuous monitoring. For this reason from summer 1996 a remote surveillance camera works on Stromboli recording continuously the volcanic activity. It is located on Pizzo Sopra la Fossa, 100 metres above the crater terrace where are the active vents. Using image analysis we seeks to identify any change of the explosive activity trend that could precede a particular eruptive event, like paroxysmal explosions, fire fountains, lava flows. From the day of the camera installation up to present 12 paroxysmal events and lava flows occurred. The analysis include the counting of the explosions occurred at the different craters and the parameterization in classes of intensity for each explosion on the base of tephra dispersion and kinetics energy. The plot of dissipated energy by each crater versus time shows a cyclic behavior with max and min of explosive activity ranging from a few days to a month. Often the craters show opposite trends so when the activity decreases in a crater, increases in the other. Before every paroxysmal explosions recorded, the crater that produced the event decreased and then stopped its activity from a few days to weeks before. The other crater tried to compensate increasing its activity and when it declined the paroxysmal explosion occurred suddenly at

  2. Impact of warming events on reef-scale temperature variability as captured in two Little Cayman coral Sr/Ca records

    NASA Astrophysics Data System (ADS)

    von Reumont, J.; Hetzinger, S.; Garbe-Schönberg, D.; Manfrino, C.; Dullo, W.-Chr.

    2016-03-01

    The rising temperature of the world's oceans is affecting coral reef ecosystems by increasing the frequency and severity of bleaching and mortality events. The susceptibility of corals to temperature stress varies on local and regional scales. Insights into potential controlling parameters are hampered by a lack of long term in situ data in most coral reef environments and sea surface temperature (SST) products often do not resolve reef-scale variations. Here we use 42 years (1970-2012) of coral Sr/Ca data to reconstruct seasonal- to decadal-scale SST variations in two adjacent but distinct reef environments at Little Cayman, Cayman Islands. Our results indicate that two massive Diploria strigosa corals growing in the lagoon and in the fore reef responded differently to past warming events. Coral Sr/Ca data from the shallow lagoon successfully record high summer temperatures confirmed by in situ observations (>33°C). Surprisingly, coral Sr/Ca from the deeper fore reef is strongly affected by thermal stress events, although seasonal temperature extremes and mean SSTs at this site are reduced compared to the lagoon. The shallow lagoon coral showed decadal variations in Sr/Ca, supposedly related to the modulation of lagoonal temperature through varying tidal water exchange, influenced by the 18.6 year lunar nodal cycle. Our results show that reef-scale SST variability can be much larger than suggested by satellite SST measurements. Thus, using coral SST proxy records from different reef zones combined with in situ observations will improve conservation programs that are developed to monitor and predict potential thermal stress on coral reefs.

  3. Holocene aeolian sedimentation and episodic mass-wasting events recorded in lacustrine sediments on Langøya in Vesterålen, northern Norway

    NASA Astrophysics Data System (ADS)

    Nielsen, Pål Ringkjøb; Dahl, Svein Olaf; Jansen, Henrik Løseth; Støren, Eivind N.

    2016-09-01

    In this study, the frequency of mass-wasting events and past storminess has been reconstructed throughout the Holocene (11,500 cal yr BP to present) from lacustrine sediments in lake Trehynnvatnet (33 m a.s.l.), which is located in a glacially carved valley at Nykvåg on the outmost coast of western Langøya, Vesterålen, northern Norway. Sediment cores (∼2-5 m long) have been examined by use of high-resolution magnetic susceptibility and XRF-scanning as well as grain size and loss-on-ignition analysis. In total 35 episodic event layers have been identified throughout the Holocene. The majority of these events are characterized as discrete coarse-grained sediment layers followed by normal grading, and are related to past mass-wasting activity within the catchment. Periods with high mass-wasting activity are dated to 11,000-10,500, 5500-4500, 4000-3500, 3000-2500, 2000-1000 and 500-0 cal yr BP. The continuous input of sand grains (>250 μm) has been systematically investigated throughout the sediment cores. The sand grains are related to catchment samples from the sandy beach deposits in Sandvikbukta c. 750 m away in SW direction, and are suggested to indicate (niveo-) aeolian influx to the lake. The content of sand grains varies greatly throughout the record, although there is a clear increase in influx of sand during the last 2800 years. Periods with high aeolian influx are proposed to indicate increased storminess, which occurred between 1600 and 1550 (350-400 CE), 1400-1300 (450-550 CE), 750-550 (1200-1400 CE) and 250-20 cal yr BP (1700-1930 CE), which to some degree coincides with periods of increased storminess and winter precipitation recorded in other studies around the North Eastern Atlantic region.

  4. A High-Resolution Absolute-Dated Penultimate Glacial Monsoon Record From Hulu and Dongge Caves, China and Global Correlations of Events Surrounding Termination II

    NASA Astrophysics Data System (ADS)

    Cheng, H.; Kelly, M. J.; Edwards, R. L.; Wang, Y.; Kong, X.; Ming, Y.; Liu, W.; Cai, Y.; An, Z.; Yuan, D.; Zhang, M.; Lin, Y.

    2004-12-01

    We have obtained the oxygen isotope record of three stalagmites from Hulu Cave (eastern China, 32° 30'N, 119° 10'E), offering a high-resolution absolute-dated record of Asian monsoon climate over much of the penultimate glacial period. Previously, stalagmites were analyzed from Dongge Cave (southern China, 25° 17'N, 108° 5'E), located approximately 1200 km to the southwest of Hulu Cave, providing a detailed account of δ 18O variations over about the same time period (Yuan et al., 2004; Kelly et al., in review). The δ 18O patterns from the Hulu and Dongge stalagmites appear to be broadly similar across the overlapping portions of the records, indicating that the stalagmites are recording a regional climate signal. Asian Monsoon climate during the penultimate glacial period follows orbitally induced insolation changes, though it is punctuated by numerous sub-orbital scale climate events. The heaviest δ 18O values during the penultimate glacial period were initiated at ˜136 ka B.P. in both records, and are largely maintained for the next ˜6 kyr until abrupt strengthening of the monsoon at Monsoon Termination II. This interval is generally characterized by less variability than seen during the earlier portions of MIS 6, with δ 18O values remaining around -5‰ . Kelly et al. (in review) have called this extended interval of time the "Weak Monsoon Interval" (WMI). The WMI, however, is punctuated by one distinct climate event, occurring at 134.5 ± 1.0 ka B.P. in the Hulu record and 133.6 ± 1.0 ka B.P. in the Dongge record. This event may correlate with warming in the Alps at 135 ± 1.2 ka B.P., as indicated by an interval of speleothem growth from Spannagel Cave (Spötl et al., 2002). We also demonstrate that the monsoon intensity correlates well with atmospheric CH4 concentrations over the last two glacial cycles. In particular, we correlate the abrupt jump in CH4 concentrations at ˜129 ka B.P. with our Monsoon Termination II. Based upon this correlation

  5. The global event system

    SciTech Connect

    Winans, J.

    1994-03-02

    The support for the global event system has been designed to allow an application developer to control the APS event generator and receiver boards. This is done by the use of four new record types. These records are customized and are only supported by the device support modules for the APS event generator and receiver boards. The use of the global event system and its associated records should not be confused with the vanilla EPICS events and the associated event records. They are very different.

  6. FAST: FAST Analysis of Sequences Toolbox

    PubMed Central

    Lawrence, Travis J.; Kauffman, Kyle T.; Amrine, Katherine C. H.; Carper, Dana L.; Lee, Raymond S.; Becich, Peter J.; Canales, Claudia J.; Ardell, David H.

    2015-01-01

    FAST (FAST Analysis of Sequences Toolbox) provides simple, powerful open source command-line tools to filter, transform, annotate and analyze biological sequence data. Modeled after the GNU (GNU's Not Unix) Textutils such as grep, cut, and tr, FAST tools such as fasgrep, fascut, and fastr make it easy to rapidly prototype expressive bioinformatic workflows in a compact and generic command vocabulary. Compact combinatorial encoding of data workflows with FAST commands can simplify the documentation and reproducibility of bioinformatic protocols, supporting better transparency in biological data science. Interface self-consistency and conformity with conventions of GNU, Matlab, Perl, BioPerl, R, and GenBank help make FAST easy and rewarding to learn. FAST automates numerical, taxonomic, and text-based sorting, selection and transformation of sequence records and alignment sites based on content, index ranges, descriptive tags, annotated features, and in-line calculated analytics, including composition and codon usage. Automated content- and feature-based extraction of sites and support for molecular population genetic statistics make FAST useful for molecular evolutionary analysis. FAST is portable, easy to install and secure thanks to the relative maturity of its Perl and BioPerl foundations, with stable releases posted to CPAN. Development as well as a publicly accessible Cookbook and Wiki are available on the FAST GitHub repository at https://github.com/tlawrence3/FAST. The default data exchange format in FAST is Multi-FastA (specifically, a restriction of BioPerl FastA format). Sanger and Illumina 1.8+ FastQ formatted files are also supported. FAST makes it easier for non-programmer biologists to interactively investigate and control biological data at the speed of thought. PMID:26042145

  7. FAST: FAST Analysis of Sequences Toolbox.

    PubMed

    Lawrence, Travis J; Kauffman, Kyle T; Amrine, Katherine C H; Carper, Dana L; Lee, Raymond S; Becich, Peter J; Canales, Claudia J; Ardell, David H

    2015-01-01

    FAST (FAST Analysis of Sequences Toolbox) provides simple, powerful open source command-line tools to filter, transform, annotate and analyze biological sequence data. Modeled after the GNU (GNU's Not Unix) Textutils such as grep, cut, and tr, FAST tools such as fasgrep, fascut, and fastr make it easy to rapidly prototype expressive bioinformatic workflows in a compact and generic command vocabulary. Compact combinatorial encoding of data workflows with FAST commands can simplify the documentation and reproducibility of bioinformatic protocols, supporting better transparency in biological data science. Interface self-consistency and conformity with conventions of GNU, Matlab, Perl, BioPerl, R, and GenBank help make FAST easy and rewarding to learn. FAST automates numerical, taxonomic, and text-based sorting, selection and transformation of sequence records and alignment sites based on content, index ranges, descriptive tags, annotated features, and in-line calculated analytics, including composition and codon usage. Automated content- and feature-based extraction of sites and support for molecular population genetic statistics make FAST useful for molecular evolutionary analysis. FAST is portable, easy to install and secure thanks to the relative maturity of its Perl and BioPerl foundations, with stable releases posted to CPAN. Development as well as a publicly accessible Cookbook and Wiki are available on the FAST GitHub repository at https://github.com/tlawrence3/FAST. The default data exchange format in FAST is Multi-FastA (specifically, a restriction of BioPerl FastA format). Sanger and Illumina 1.8+ FastQ formatted files are also supported. FAST makes it easier for non-programmer biologists to interactively investigate and control biological data at the speed of thought.

  8. Are historical pollution events on the Delaware River recorded as geochemical marker horizons in adjacent marsh sediments

    SciTech Connect

    Walsh, R.; Yemane, K. . Dept. of Geology Bryn Mawr Coll., PA . Geology Dept.)

    1993-03-01

    In the last two hundred years of massive population and industrial growth, the Delaware River has been subjected to several minor and major pollutions. For example, as recently as June 1989 the tanker Presidente Rivera spilled an estimated hundred thousand to million gallons of oil into the river. In the Lower Delaware Basin tides affect the river and its tributaries up to a hundred kilometers inland. The freshwater marshes adjacent to the creeks that empty into the Delaware River experience diurnal tidal sedimentation. It is thus expected that the pollutants in the waterway would be transported via the tidal channels into the adjacent wetlands. The high sedimentation rate, clay-rich sediments, accumulation of terrestrial organic matter, and the low energy environments in these marshes should ensure rapid burial which may preserve some of the contaminants transported into the marshes. To test this hypothesis the authors selected a freshwater marsh along the Raccoon Creek just south of Philadelphia in New Jersey, and collected a 2 m core from a relatively undisturbed portion of the marsh, about 15 m away from the tidal channels. The pH averages around 6.2, ranges from 5.5--6.8, but, is slightly higher in the middle part of the core. The bulk mineralogy comprises chlorite, illite, kaolinite, feldspars and quartz. Vivianite and vermiculite were observed at places lower in the core. Graminae dominates the pollen/spore taxa. The organic debris is unaltered throughout the core. The authors will measure heavy metals and toxic chemicals on < 2[mu]m clay fractions. Also pristane/phytane ratios, indicative of hydrocarbons (crude oils), will be determined on organic matter extracts. The authors will compare and correlate the results to historically documented events of chemical and petroleum spills on the Delaware River.

  9. The record of Miocene climatic events in AND-2A drill core (Antarctica): Insights from provenance analyses of basement clasts

    NASA Astrophysics Data System (ADS)

    Sandroni, Sonia; Talarico, Franco M.

    2011-01-01

    This paper includes the results of a detailed quantitative provenance investigation on gravel-size clasts occurring within the late Early to Late Miocene sedimentary glacimarine section recovered for the first time by the AND-2A core in the SW sector of the Ross Sea (southern McMurdo Sound, Antarctica). This period of time is of crucial interest, as it includes two of the major Cenozoic events in the global climatic evolution: the mid-Miocene climatic optimum and the middle Miocene climate transition. Petrographical and mineral chemistry data on basement clasts allow to individuate two different diagnostic clast assemblages, which clearly suggest two specific sectors of southern Victoria Land as the most likely sources: the Mulock-Skelton glacier and the Koettlitz-Blue glacier regions. Distribution patterns reveal high fluctuations of the detritus source areas throughout the investigated core interval, variations which can be interpreted as the direct result of an evolving McMurdo Sound paleogeography during the late Early to Late Miocene. Consistently with sedimentological studies, gravel-fraction clast distribution patterns clearly testify that the Antarctic ice sheet experienced a dramatic contraction at ca. 17.35 ± 0.14 Ma (likely correlated to the onset of the climatic optimum), and in a < ca. 100 ka time window passing from a glacial scenario comparable to the last glacial maximum (Phase 1) to a very dynamic glacial environment (Phase 2). Phase 2 conditions persisted through the early Middle Miocene (to ca. 14.2 Ma), when a major expansion of the Antarctic ice sheet is hypothesized, likely contemporaneously to the onset of the middle Miocene climate transition. Therefore, provenance and distribution studies of gravel-fraction clasts show that the variations of paleoenvironmental drivers characterising this period were able to exert deep transformation of the Antarctic ice sheet and reveal the methodology to be a powerful tool for the reconstruction of paleo

  10. Missing Rings in Pinus halepensis - The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events.

    PubMed

    Novak, Klemen; de Luis, Martin; Saz, Miguel A; Longares, Luis A; Serrano-Notivoli, Roberto; Raventós, Josep; Čufar, Katarina; Gričar, Jožica; Di Filippo, Alfredo; Piovesan, Gianluca; Rathgeber, Cyrille B K; Papadopoulos, Andreas; Smith, Kevin T

    2016-01-01

    Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees

  11. Missing Rings in Pinus halepensis – The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events

    PubMed Central

    Novak, Klemen; de Luis, Martin; Saz, Miguel A.; Longares, Luis A.; Serrano-Notivoli, Roberto; Raventós, Josep; Čufar, Katarina; Gričar, Jožica; Di Filippo, Alfredo; Piovesan, Gianluca; Rathgeber, Cyrille B. K.; Papadopoulos, Andreas; Smith, Kevin T.

    2016-01-01

    Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees

  12. Missing Rings in Pinus halepensis - The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events.

    PubMed

    Novak, Klemen; de Luis, Martin; Saz, Miguel A; Longares, Luis A; Serrano-Notivoli, Roberto; Raventós, Josep; Čufar, Katarina; Gričar, Jožica; Di Filippo, Alfredo; Piovesan, Gianluca; Rathgeber, Cyrille B K; Papadopoulos, Andreas; Smith, Kevin T

    2016-01-01

    Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees

  13. Plant wax δD values record changing Eastern Mediterranean atmospheric circulation patterns during the 8.2 kyr B.P. climatic event

    NASA Astrophysics Data System (ADS)

    Schemmel, Fabian; Niedermeyer, Eva M.; Schwab, Valérie F.; Gleixner, Gerd; Pross, Jörg; Mulch, Andreas

    2016-02-01

    Throughout the Holocene, the climate of the Mediterranean region has been strongly influenced by variability in the atmospheric circulation of the high and low latitudes. A prominent example for such Holocene climate perturbations is the '8.2 kyr B.P. climatic event'. Reorganization of Northern Hemisphere atmospheric circulation patterns resulted in variations of temperature and precipitation distribution across the Mediterranean. The effects of changing high- and low-latitude atmospheric circulation on Mediterranean climate in relation to the 8.2 kyr B.P. climatic event are, however, not well understood. Here we present a high-resolution record of stable hydrogen isotope composition of plant-wax n-alkanes (δDwax) across the 8.2 kyr B.P. climatic event from the Tenaghi Philippon peat deposit (NE Greece) in order to characterize patterns of precipitation and changes in atmospheric circulation in the Eastern Mediterranean region. Our record reveals pronounced changes in δDwax that correlate closely with previously published palynological data. A long-term decline in δDwax values characterizes the lower part of the section. The 8.2 kyr B.P. climatic event itself is connected to two distinct positive δDwax excursions: a minor shift in δDwax around 8.2 kyr B.P. and a major shift in δDwax between ca. 8.1 and 8.0 kyr B.P.. The upper part of the section shows a progressive trend towards higher δDwax values. We link shifts in δDwax to changes in Mediterranean air mass trajectories supplying precipitation to NE Greece caused by variations in the relative contributions of northerly-derived, D-depleted moisture and southerly-derived, D-enriched moisture. Possible control mechanisms for alternating air mass trajectories include changes in the influence of the Siberian High and differences in the influence of the African and Asian monsoon circulation on anticyclonic conditions in the Mediterranean region as well as regional inflow of moist air masses from the Aegean Sea.

  14. Integrated wireless fast-scan cyclic voltammetry recording and electrical stimulation for reward-predictive learning in awake, freely moving rats

    NASA Astrophysics Data System (ADS)

    Li, Yu-Ting; Wickens, Jeffery R.; Huang, Yi-Ling; Pan, Wynn H. T.; Chen, Fu-Yu Beverly; Chen, Jia-Jin Jason

    2013-08-01

    Objective. Fast-scan cyclic voltammetry (FSCV) is commonly used to monitor phasic dopamine release, which is usually performed using tethered recording and for limited types of animal behavior. It is necessary to design a wireless dopamine sensing system for animal behavior experiments. Approach. This study integrates a wireless FSCV system for monitoring the dopamine signal in the ventral striatum with an electrical stimulator that induces biphasic current to excite dopaminergic neurons in awake freely moving rats. The measured dopamine signals are unidirectionally transmitted from the wireless FSCV module to the host unit. To reduce electrical artifacts, an optocoupler and a separate power are applied to isolate the FSCV system and electrical stimulator, which can be activated by an infrared controller. Main results. In the validation test, the wireless backpack system has similar performance in comparison with a conventional wired system and it does not significantly affect the locomotor activity of the rat. In the cocaine administration test, the maximum electrically elicited dopamine signals increased to around 230% of the initial value 20 min after the injection of 10 mg kg-1 cocaine. In a classical conditioning test, the dopamine signal in response to a cue increased to around 60 nM over 50 successive trials while the electrically evoked dopamine concentration decreased from about 90 to 50 nM in the maintenance phase. In contrast, the cue-evoked dopamine concentration progressively decreased and the electrically evoked dopamine was eliminated during the extinction phase. In the histological evaluation, there was little damage to brain tissue after five months chronic implantation of the stimulating electrode. Significance. We have developed an integrated wireless voltammetry system for measuring dopamine concentration and providing electrical stimulation. The developed wireless FSCV system is proven to be a useful experimental tool for the continuous

  15. Is our Future Written in the Geological Record of Oceanic Anoxic Events? The Calcareous Nannoplankton Perspective (Invited)

    NASA Astrophysics Data System (ADS)

    Erba, E.

    2013-12-01

    The topical emergence of climate change as a crucial issue for society and governments has urged the understanding of the future state of the planet within the context of increasing carbon dioxide concentrations. In the near future, the ocean's uptake of CO2 is expected to rapidly decline because of surface warming, increased vertical stratification, and slowed thermohaline circulation. The Anthropocene CO2 emissions are inferred to be the cause of global warming and alteration of ocean chemistry, triggering unknown responses of marine biota in terms of extinction, innovation and/or temporary adaptations. During the Mesozoic under excess CO2 and greenhouse conditions, the ocean became depleted of oxygen, promoting the burial of massive amounts of organic matter. These episodes are named Oceanic Anoxic Events (OAEs) and might provide guidance as to the response of marine biota to massive CO2 releases and how and at what rate pre-perturbation conditions are eventually restored. After over three decades of research on OAEs, an impressive amount of data has been generated: there is a general consensus on the role of Large Igneous Provinces (LIPs) inducing CO2 increases, greenhouse climate and profound variations in chemical, physical and trophic characteristics of the ocean. OAEs can be studied to decipher the complexity of drivers and of responses within and among different organisms to CO2 pulses, extreme warmth, weathering changes, ocean fertilization and acidification to add the long-term and large-scale prospective to investigations on current, very-short-term and local responses. In Jurassic and Cretaceous oceans, coccolithophores were already a most efficient carbonate-forming group and OAEs offer the opportunity of characterizing variations in their abundance, diversity, and morphology to trace ecological affinities and adaptations to oceanic ecosystem perturbations. We quantitatively investigated the Toarcian OAE, the early Aptian OAE1a and the latest

  16. Multiple metasomatic events recorded in Kilbourne Hole peridotite xenoliths: the relative contribution of host basalt interaction vs. silicate metasomatic glass

    NASA Astrophysics Data System (ADS)

    Hammond, S. J.; Yoshikawa, M.; Harvey, J.; Burton, K. W.

    2010-12-01

    Stark differences between bulk-rock lithophile trace element budgets and the sum of the contributions from their constituent minerals are common, if not ubiquitous in peridotite xenoliths [1]. In the absence of modal metasomatism this discrepancy is often attributed to the “catch-all”, yet often vague process of cryptic metasomatism. This study presents comprehensive Sr-Nd isotope ratios for variably metasomatized bulk-rock peridotites, host basalts, constituent peridotite mineral phases and interstitial glass from 13 spinel lherzolite and harzburgite xenoliths from the Kilbourne Hole volcanic maar, New Mexico, USA. Similar measurements were also made on hand-picked interstitial glass from one of the most highly metasomatized samples (KH03-16) in an attempt to unravel the effects of multiple metasomatic events. In all Kilbourne Hole peridotites analysed, hand-picked, optically clean clinopyroxenes preserve a more primitive Sr isotope signature than the corresponding bulk-rock; a pattern preserved in all but one sample for Nd isotope measurements. Reaction textures, avoided during hand-picking, around clinopyroxene grains are evident in the most metasomatized samples and accompanied by films of high-SiO2 interstitial glass. The margins of primary minerals appear partially resorbed and trails of glassy melt inclusions similar in appearance to those previously reported from the same locality [2], terminate in these films. Hand-picked glass from KH03-16 reveals the most enriched 87Sr/86Sr of any component recovered from these xenoliths (87Sr/86Sr = 0.708043 ± 0.00009; [Sr] = 81 ppm). Similarly, the 143Nd/144Nd of the glass is amongst the most enriched of the peridotite components (143Nd/144Nd = 0.512893 ± 0.000012; [Nd] = 10 ppm). However, the host basalt (87Sr/86Sr = 0.703953 ± 0.00012; 143Nd/144Nd = 0.512873 ± 0.000013), similar in composition to nearby contemporaneous Potrillo Volcanic Field basalts [3], contains nearly an order of magnitude more Sr and more

  17. Record of Plio-Pleistocene extreme event in the Lesser Antilles fore-arc basin. Example of Grande-Terre (Guadeloupe, French West Indies).

    NASA Astrophysics Data System (ADS)

    Jeanlèn, L.; Philippon, M. M.; Randrianasolo, A.; Jean-Frederic, L.; Cornée, J. J.; Münch, P.

    2015-12-01

    Guadeloupe archipelago is part of the Lesser Antilles active volcanic arc and is therefore subjected to both enhanced seismic and volcanic activity related to the Lesser Antilles subduction zone, along which the Atlantic plate is subducted westward bellow the Caribbean plate. The volcanic arc is composed of several immerged volcanic islands (St Kitts, Nevis Montserrat, Basse Terre, Dominica, Martinique, St Lucia, Grenada) and submerged volcanoes (Kick em'Jenny). These volcanoes are known to be explosives and when they are entering in an eruptive cycle, debris flow could potentially initiate a tsunami and generate peculiar deposits within the sedimentary record recognized as tsunami deposits (or tsunamite). Subduction- related earthquakes might also initiate slope instabilities and trigger debris flow. Another controlling factor of slope (in-)-stabilities and debris flow is massive rainfalls. During cyclonic season (June to December), massive rainfalls are recorded in the area, which moreover is located on the trajectory of Atlantic Hurricanes that are responsible for numerous landslides. As a consequence, tsunami deposit are described and well studied in the Lesser Antilles arc as the islands shoreline and coastal plain are perpetually re-shaped by hurricanes responsible for tempestite deposits. However, the report of these deposit concern recent to actual events, for example present-day deposits consisting of large (metric) boulders, more or less aligned, located in the supralittoral fringe can be observed along Guadeloupe shore. In this study, we investigate the Plio-pleistocene sedimentary sequence of Grande Terre carbonate platform (Guadeloupe), and track the presence of such extreme-event related deposits and discuss our findings in the frame of the Lesser Antilles geological context.

  18. In situ record of sedimentary processes near the Rhône River mouth during winter events (Gulf of Lions, Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Marion, C.; Dufois, F.; Arnaud, M.; Vella, C.

    2010-05-01

    us to link both river flow and wind characteristics to events recorded on the sea floor, i.e. resuspension, accumulation, consolidation, etc. Deposits of 11 cm of sediments were estimated during flood periods and bottom shear stresses up to 5 N m -2 were calculated during sediment erosion phases.

  19. In-Flight Observations of Long-Term Single Event Effect(SEE)Performance on Orbview-2 and Xray Timing Explorer(XTE)Solid State Recorders (SSR)

    NASA Technical Reports Server (NTRS)

    Poivey, Christian; Barth, Janet L.; LaBel, Ken A.; Gee, George; Safren, Harvey

    2003-01-01

    This paper presents Single Event Effect (SEE) in-flight data on Solid State Recorders (SSR) that have been collected over a long period of time for two NASA spacecraft: Orbview-2 and XTE. SEE flight data on solid-state memories give an opportunity to study the behavior in space of SEE sensitive commercial devices. The actual Single Event Upset (SEU) rates can be compared with the calculated rates based on environment models and ground test data. The SEE mitigation schemes can also be evaluated in actual implementation. A significant amount of data has already been published concerning observed SEE effects on memories in space. However, most of the data presented cover either a short period of time or a small number of devices. The data presented here has been collected on a large number of devices during several years. This allows statistically significant information about the effect of space weather fluctuations on SEU rates, and the effectiveness of SEE countermeasures used to be analyzed. Only Orbview-2 data is presented in this summary. XTE data will be included in the final paper.

  20. Pyrite framboid size distribution as a record for relative variations in sedimentation rate: An example on the Toarcian Oceanic Anoxic Event in Southiberian Palaeomargin

    NASA Astrophysics Data System (ADS)

    Gallego-Torres, David; Reolid, Matías; Nieto-Moreno, Vanesa; Martínez-Casado, Francisco Javier

    2015-12-01

    The Early Toarcian Oceanic Anoxic Event (T-OAE) represents one of the major alterations of the carbon cycle of the Mesozoic period. Despite being globally recognized, and particularly represented within the Tethys realm, its expression in the sedimentary record is highly variable depending on the studied section, which suggests local environmental factors exert a major control on the resulting lithological appearance of the event. We investigated the Fuente Vidriera section, in the eastern External Subbetic of the Betic Cordillera (Spain), where the Lower Jurassic is represented by alternate layers of marls and marly limestones, and the T-OAE is identified by a major δ13C excursion, micropalaeontological, ichnofacies and geochemical evidences. For this study, we analyzed pyrite framboid size distribution of the sedimentary sequence in Fuente Vidriera. The outcome, according to previous studies on pyrite framboid distribution, is contradictory when compared to all other evidences, suggesting oxygen depletion during the T-OAE. The results have been reinterpreted in the light of Crystal Size Distribution Theory and we conclude that not only growth time but also geochemical environment controls pyrite formation. Since growth time is directly related to burial rates, this approach allows us to reconstruct relative variations of sedimentation rates during the Early Jurassic in this location. Based on the obtained results, we provide new evidences for wide-spread transgression during the Early Toarcian in the South Iberian palaeomargin, which induced low sedimentation rate and lower energetic conditions, as well as favored oxygen impoverished bottom waters.

  1. Facies analyses of cold-water spring-fed fluvial carbonates: Implications for a terrestrial Holocene (?) record of wet events in Southern California

    NASA Astrophysics Data System (ADS)

    Ibarra, Y.; Corsetti, F. A.; Feakins, S. J.

    2012-12-01

    was active. The presence of groundwater-fed carbonate deposits in this region constitute a unique opportunity to compare/compliment a record of terrestrial wet events to proximal high-resolution records of Holocene climate from the sediments of Zaca Lake located about 2km away and the diverse assemblage of Holocene climate records from the Santa Barbara Basin located about 50km to the south.

  2. Synchronisation of palaeoenvironmental records over the last 60,000 years, and an extended INTIMATE1 event stratigraphy to 48,000 b2k

    NASA Astrophysics Data System (ADS)

    Blockley, Simon P. E.; Lane, Christine S.; Hardiman, Mark; Rasmussen, Sune Olander; Seierstad, Inger K.; Steffensen, Jørgen Peder; Svensson, Anders; Lotter, Andre F.; Turney, Chris S. M.; Bronk Ramsey, Christopher; Intimate Members

    2012-03-01

    The INTIMATE protocol for the correlation of marine ice core and terrestrial records is here updated, reflecting recent developments in palaeoclimate research. Originally focussed on Last Glacial to Interglacial Transition (LGIT: 22,000-11,500 years B.P.), the INTIMATE group has now extended its study period back to 60,000 years. As a first step, the INTIMATE event stratigraphy has now been extended to include 8000-48,000 b2k based on a combined NGRIP and GRIP isotope profile against a GICC05 chronology and key tephra horizons from Iceland and continental European volcanic sources. In this lead article of this INTIMATE special issue we introduce some of the recent achievements of the INTIMATE community and discuss the challenges associated with extending the INTIMATE approach back in time, focussing in particular on the chronological problems inherent in comparing different proxy records. The INTIMATE approach has thus far been limited predominantly to the North Atlantic and Australasian regions and we also discuss the potential to extend the INTIMATE protocol beyond these regions.

  3. Fast neutron imaging device and method

    DOEpatents

    Popov, Vladimir; Degtiarenko, Pavel; Musatov, Igor V.

    2014-02-11

    A fast neutron imaging apparatus and method of constructing fast neutron radiography images, the apparatus including a neutron source and a detector that provides event-by-event acquisition of position and energy deposition, and optionally timing and pulse shape for each individual neutron event detected by the detector. The method for constructing fast neutron radiography images utilizes the apparatus of the invention.

  4. A 400-kyr record of millennial-scale carbonate preservation events in the Southern Ocean: Implications for Atlantic Meridional Overturning Circulation and atmospheric CO2

    NASA Astrophysics Data System (ADS)

    Hodell, D. A.; Vautravers, M. J.; Barker, S.; Charles, C.; Crowhurst, S.

    2014-12-01

    Hodell et al. (2001) suggested that carbonate preservation in the deep Cape Basin represented a qualitative, high-resolution record of the temporal evolution of the carbonate saturation state of the deep sea. The carbonate signal reflects both transient events in the redistribution of alkalinity and DIC in the deep ocean and steady-state mass balance processes. Here we re-analyzed the carbonate records of Sites 1089/TN057-21 using an Avaatech XRF core scanner and measured elemental variations at 2.5-mm resolution for the past 400 kyrs. Log Ca/Ti is highly correlated to weight percent carbonate content and other dissolution proxies and resolves millennial-scale events in carbonate preservation. A high-pass filter removes the low-frequency (orbital) variability in carbonate preservation, which is attributed mainly to steady-state mass balance processes. The high-frequency (suborbital) component reflects transient responses to the redistribution of carbonate ion that is related mainly to changing deep-water circulation. During the last glacial period, distinct millennial-scale increases in carbonate preservation in piston core TN057-21 occurred during times of enhanced Atlantic Meridional Overtunring Circulation (AMOC) (Barker et al., 2010; Barker and Diz, 2014), as supported by increases in benthic δ13C and less radiogenic ɛNd values. Carbonate preservation peaked particularly during long, warm interstadials in Greenland when a deep water mass with high carbonate ion concentration was formed in the North Atlantic. Export of NADW may have been greater than the Holocene during some of these events ("overshoots") and/or preformed carbonate ion concentrations in North Atlantic source areas may have been higher owing to lower atmospheric CO2 and less carbonate production in surface water. Each South Atlantic carbonate peak is associated with the start of Antarctic cooling and declining or leveling of atmospheric CO2, reflecting the signature of a thermal bipolar seesaw

  5. Mapping South American Summer Monsoon Changes during Heinrich Event 1 and the LGM: Insights from New Paleolake Records from the Central Andes

    NASA Astrophysics Data System (ADS)

    Chen, C. Y.; McGee, D.; Quade, J.

    2015-12-01

    Cave stalagmite records show strong evidence of abrupt changes in summer monsoons during Heinrich events, but we lack rigorous constraints on the amount of wetting or drying occurring in monsoon regions. Studies on shoreline deposits of closed-basin lakes can establish quantitative bounds on water balance changes through mapping-based estimates of lake volume variations. We present new dating constraints on lake level variations in Agua Caliente I and Laguna Loyoques, two closed-basin, high-altitude paleolakes on the Altiplano-Puna plateau of the Central Andes (23.1°S, 67.4°W, 4250 masl). Because this area receives >70% of its total annual precipitation during austral summer, the region is ideally suited to capture a pure response to changes in the South American summer monsoon (SASM). The plateau is home to several small (<40 km2) lakes surrounded by well-preserved paleoshorelines that indicate past wetter conditions. Agua Caliente I is unique, having multiple shorelines encrusted with biologically-mediated calcium carbonate "tufa" deposits. Initial U-Th dating of these massive shoreline tufas reveals that these deposits are dateable to within ±50 to 300 years due to high U concentrations and low initial Th content (as indicated by high 230Th/232Th). Our U-Th dates show that Agua Caliente I was greater in lake surface area during two periods: 17.5-14.5 kyrs BP, coincident with Heinrich Event 1 (HE1), and 24-23 kyrs BP, roughly coincident with the Last Glacial Maximum (LGM). At these times, Agua Caliente I also overflowed into a neighboring lake basin (Loyoques) through an 8-km long southeast-trending stream channel. Thus, during HE1 and the LGM, the lake was ~9 times larger in surface area relative to modern. Hydrologic modeling constrained by paleotemperature estimates is used to provide bounds for these past precipitation changes. We also tentatively explore physical mechanisms linking Heinrich events and the regional hydroclimate by comparing freshwater

  6. News Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

    NASA Astrophysics Data System (ADS)

    2011-01-01

    Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

  7. The possible importance of synchrotron/inverse Compton losses to explain fast MM-wave and hard X-ray emission of a solar event

    NASA Technical Reports Server (NTRS)

    Correia, E.; Kaufmann, P.; Costa, J. E. R.; Vaz, A. M. Z.; Dennis, B. R.

    1986-01-01

    The solar burst of 21 May 1984 presented a number of unique features. The time profile consisted of seven major structures (seconds), with a turnover frequency or approx. 90 GHz, well correlated in time to hard X-ray emission. Each structure consisted of multiple fast pulses (.1 seconds), which were analyzed in detail. A proportionality between the repetition rate of the pulses and the burst fluxes at 90 GHz and or approx. 100 keV hard X-rays, and an inverse proportionality between repetition rates and hard X-rays power law indices have been found. A synchrotron/inverse Compton model has been applied to explain the emission of the fast burst structures, which appear to be possible for the first three or four structures.

  8. The possible importance of synchrotron/inverse Compton losses to explain fast mm-wave and hard X-ray emission of a solar event

    NASA Technical Reports Server (NTRS)

    Correia, E.; Kaufmann, P.; Costa, J. E. R.; Zodivaz, A. M.; Dennis, B. R.

    1986-01-01

    The solar burst of 21 May 1984, presented a number of unique features. The time profile consisted of seven major structures (seconds), with a turnover frequency of greater than or approximately 90 GHz, well correlated in time to hard X-ray emission. Each structure consisted of multiple fast pulses (0.1 seconds), which were analyzed in detail. A proportionality between the repetition rate of the pulses and the burst fluxes at 90 GHz and greater than or approximately 100 keV hard X-rays, and an inverse proportionality between repetition rates and hard X-ray power law indices were found. A synchrotron/inverse Compton model was applied to explain the emission of the fast burst structures, which appear to be possible for the first three or four structures.

  9. Autocharacterization feasibility system on Hunters Trophy event

    SciTech Connect

    Mills, R.A.

    1993-09-01

    An automated system to characterize cable systems at NTS has been developed to test the feasibility of such a system. A rack of electronic equipment including a fast pulse generator, digital sampling scope, coaxial switch matrix and GPIB controller was installed downhole at NTS for the Hunters Trophy event. It was used to test automated characterization. Recorded measurements of simulation and other instrument data were gathered to determine if a full scale automated system would be practical in full scale underground nuclear effects tests. The benefits of such a full scale system would be fewer personnel required downhole; more instrument control in the uphole recording room; faster acquisition of cable parameter data.

  10. Early Eocene hyperthermal events ETM2, H2 and I1 as recorded by Tethyan planktic foraminifera in the Terche section (northernastern Italy)

    NASA Astrophysics Data System (ADS)

    D'Onofrio, Roberta; Luciani, Valeria; Giusberti, Luca; Fornaciari, Eliana; Sprovieri, Mario

    2014-05-01

    In the last years, several transient episodes of extreme warming, the so-called hyperthermals, have been recognized in addition to the well-know Paleocene-Eocene Thermal Maximum (PETM; ~55.5 Ma), superimposed on the long-term Paleocene-early Eocene warming trend peaking in the Early Eocene Climatic Optimum (EECO). To the present, perturbations produced by hyperthermals are well documented in terms of isotopic variations whereas their influence on the biota is still largely unexplored. The Terche section, located in the Venetian Pre-Alps (northeastern Italy), is an expanded latest Paleocene-lower Eocene succession deposited in a bathyal setting of a continental margin of the central-western Tethys. This section is particularly suitable to study post-PETM hyperthermals because it contains three well-exposed and expanded marly-clayey units (MUs) corresponding to intervals of negative carbon isotope excursions (CIEs). Calcareous plankton biostratigraphy allow us to refer them to the hyperthermals ETM2 (or H1; ~53.7 Ma), H2 (~53.6 Ma) and I1(~53.3 Ma). Here we present the first detailed quantitative analysis of planktic foraminiferal assemblages across these early Eocene hyperthermals events. Quantitative analysis of planktic foraminiferal genera shows a long-term trend of variation upon which higher frequency variations are superimposed. We interpret such long-term variation as the response to the long-term warming trend since it highlights a slight increase of the warm indicators, such as the acarininids, and decrease of the cold form subbotinids. The high frequency variations, instead, closely related to the CIEs and to the MUs, record a pronounced increase in acarininids (up to 68%) and a parallel marked decline in the abundances of subbotinids and other component of planktic foraminiferal assemblages. The MUs are also associated with an increase of the eutrophic radiolarians. This aspect, together with the dominance of acarininids, can be interpreted as a

  11. Path-specific, dispersion-based velocity models and moment tensors of moderate events recorded at few distant stations: Examples from Brazil and Greece

    NASA Astrophysics Data System (ADS)

    Dias, Fabio; Zahradník, Jiří; Assumpção, Marcelo

    2016-11-01

    Centroid moment tensor (CMT) determination in intraplate regions like Brazil can be very difficult, because earthquakes are often recorded just at few and distant stations. This paper introduces a methodology for datasets like that. The methodology is based on waveform inversion in which each source-station path has its own velocity model. The 1-D path-specific velocity models are derived from the Rayleigh- and Love-wave dispersion curves. The waveform inversion is accompanied by posterior check of numerous P-wave first-motion polarities. An important innovation is the use of so-called frequency range test. The test basically consists in calculating CMT's for many different frequency ranges to assess the stability and uncertainty of the solution. The method is validated on two Brazilian earthquakes and a well-known Greek event. An offshore event (mb 5.2) in SE Brazil is inverted with four stations, at epicentral distances 300-400 km. The other Brazilian earthquake (mb 4.8 in Central Brazil) is even more challenging - only two broadband stations at 800-1300 km are at disposal for waveform inversion. The paper unambiguously demonstrates that the path-specific velocity models significantly increase the reliability of the CMT's. While standard models (e.g. IASP91) typically allow waveform modeling up to epicentral distances of the order of a few (∼10) minimum shear wavelengths (MSW), using the path-specific velocity models we successfully inverted waveforms up to > 20 MSW. Single-station waveform inversions are thoroughly tested, but multi-station joint inversions are shown to be preferable. The new methodology of this paper, providing a reasonable estimate of focal mechanisms and their uncertainties in case of highly limited waveform data, may find broad applicability in Brazil and elsewhere.

  12. The Effects of Colchicine on Risk of Cardiovascular Events and Mortality Among Patients with Gout: A Cohort Study Using Electronic Medical Records Linked with Medicare Claims

    PubMed Central

    Solomon, Daniel H.; Liu, Chih-Chin; Kuo, I-Hsin; Zak, Agnes; Kim, Seoyoung C.

    2016-01-01

    Background Colchicine may have beneficial effects on cardiovascular (CV) disease, but there are sparse data on its CV effect among patients with gout. We examined the potential association between colchicine and CV risk and all-cause mortality in gout. Methods The analyses used data from an electronic medical record (EMR) database linked with Medicare claims (2006–2011). To be eligible for the study cohort, subjects must have had a diagnosis of gout in the EMR and Medicare claims. New users of colchicine were identified and followed-up from the first colchicine dispensing date. Non-users had no evidence of colchicine prescriptions during the study period and were matched to users on the start of follow-up, age, and gender. Both groups were followed for the primary outcome, a composite of myocardial infarction (MI), stroke or transient ischemic attack (TIA). We calculated hazard ratios (HRs) in Cox regression, adjusting for potential confounders. Results We matched 501 users with an equal number of non-users with a median follow-up of 16.5 months. During follow-up, 28 primary CV events were observed among users and 82 among non-users. Incidence rates per 1,000 person-years were 35.6 for users and 81.8 for non-users. After full adjustment, colchicine use was associated with a 49% lower risk (HR 0.51, 95% CI 0.30 – 0.88) in the primary CV outcome as well as a 73% reduction in all-cause mortality (HR 0.27, 95% CI 017 – 0.43). Conclusion Colchicine use was associated with a reduced risk of a CV event among patients with gout. PMID:26582823

  13. Iron isotope and trace metal records of iron cycling in the proto-North Atlantic during the Cenomanian-Turonian oceanic anoxic event (OAE-2)

    NASA Astrophysics Data System (ADS)

    Owens, Jeremy D.; Lyons, Timothy W.; Li, Xiaona; MacLeod, Kenneth G.; Gordon, Gwenyth; Kuypers, Marcel M. M.; Anbar, Ariel; Kuhnt, Wolfgang; Severmann, Silke

    2012-09-01

    The global carbon cycle during the mid-Cretaceous (˜125-88 million years ago, Ma) experienced numerous major perturbations linked to increased organic carbon burial under widespread, possibly basin-scale oxygen deficiency and episodes of euxinia (anoxic and H2S-containing). The largest of these episodes, the Cenomanian-Turonian boundary event (ca. 93.5 Ma), or oceanic anoxic event (OAE) 2, was marked by pervasive deposition of organic-rich, laminated black shales in deep waters and in some cases across continental shelves. This deposition is recorded in a pronounced positive carbon isotope excursion seen ubiquitously in carbonates and organic matter. Enrichments of redox-sensitive, often bioessential trace metals, including Fe and Mo, indicate major shifts in their biogeochemical cycles under reducing conditions that may be linked to changes in primary production. Iron enrichments and bulk Fe isotope compositions track the sources and sinks of Fe in the proto-North Atlantic at seven localities marked by diverse depositional conditions. Included are an ancestral mid-ocean ridge and euxinic, intermittently euxinic, and oxic settings across varying paleodepths throughout the basin. These data yield evidence for a reactive Fe shuttle that likely delivered Fe from the shallow shelf to the deep ocean basin, as well as (1) hydrothermal sources enhanced by accelerated seafloor spreading or emplacement of large igneous province(s) and (2) local-scale Fe remobilization within the sediment column. This study, the first to explore Fe cycling and enrichment patterns on an ocean scale using iron isotope data, demonstrates the complex processes operating on this scale that can mask simple source-sink relationships. The data imply that the proto-North Atlantic received elevated Fe inputs from several sources (e.g., hydrothermal, shuttle and detrital inputs) and that the redox state of the basin was not exclusively euxinic, suggesting previously unknown heterogeneity in

  14. Holter and Event Monitors

    MedlinePlus

    ... Holter and event monitors are similar to an EKG (electrocardiogram). An EKG is a simple test that detects and records ... for diagnosing heart rhythm problems. However, a standard EKG only records the heartbeat for a few seconds. ...

  15. Seasonality and Disturbance Events in the Carbon Isotope Record of Slash Pine (Pinus elliottii) Tree Rings from Big Pine Key, Florida

    NASA Astrophysics Data System (ADS)

    Rebenack, C.; Anderson, W. T.; Cherubini, P.

    2011-12-01

    The South Florida coastal ecosystem is among the world's subtropical coastlines which are threatened by the potential effects of climate change. A well-developed localized paleohistory is essential in the understanding of the role climate variability/change has on both hydrological dynamics and disturbance event frequency and intensity; this understanding can then aid in the development of better predictive models. High resolution paleoclimate proxies, such as those developed from tree-ring archives, may be useful tools for extrapolating actual climate trends over time from the overlapping long-term and short-term climate cycles, such as the Atlantic Multidecadal Oscillation (AMO) and the El Niño-Southern Oscillation (ENSO). In South Florida, both the AMO and ENSO strongly influence seasonal precipitation, and a more complete grasp of how these cycles have affected the region in the past could be applied to future freshwater management practices. Dendrochronology records for the terrestrial subtropics, including South Florida, are sparse because seasonality for this region is precipitation driven; this is in contrast to the drastic temperature changes experienced in the temperate latitudes. Subtropical seasonality may lead to the complete lack of visible rings or to the formation of ring structures that may or may not represent annual growth. Fortunately, it has recently been demonstrated that Pinus elliottii trees in South Florida produce distinct annual growth rings; however ring width was not found to significantly correlate with either the AMO or ENSO. Dendrochronology studies may be taken a step beyond the physical tree-ring proxies by using the carbon isotope ratios to infer information about physiological controls and environmental factors that affect the distribution of isotopes within the plant. It has been well established that the stable isotope composition of cellulose can be related to precipitation, drought, large-scale ocean/atmospheric oscillations

  16. Connecting the Final Drainage of Lake Agassiz to the 8.2 ka Event by Means of a High- Resolution Sea-Level Record From the Mississippi Delta

    NASA Astrophysics Data System (ADS)

    Li, Y.; Tornqvist, T. E.; Nevitt, J. M.; Shen, Z.; Yu, S.

    2008-12-01

    The catastrophic drainage of proglacial lakes Agassiz and Ojibway (LAO) in the early Holocene is widely believed to have triggered the 8.2 ka cold event. The timing of the LAO drainage, however, remains poorly constrained, which impedes our understanding of the abruptness of this climate change in response to a rapid freshwater forcing. Dating of the LAO drainage in the Hudson Bay area (Barber et al., 1999) yielded an age of 8.47 ± 0.30 ka, thus leaving large uncertainties about its connection with the 8.2 ka event. Here we refine the chronology of the final LAO drainage by constructing a high-resolution sea-level record from the Mississippi Delta with the basal peat approach. Two separate basal peat beds are interpreted to bracket an abrupt sea-level rise around 8.2 ka. The stratigraphically deeper level (Level A) contains a 2 cm basal peat layer that is abruptly overlain by Rangia cuneata- bearing lagoonal muds, representing the onset of an abrupt sea-level rise. The stratigraphically shallower level (Level B) contains a 6 cm basal peat layer that is covered by organic-rich muds, representing the end of the abrupt sea-level rise. Radiocarbon dating of different fractions of macrofossils from each peat layer yields consistent ages. The peat layer from Level A and the base of the peat layer from Level B yield ages of 8257 Cal. yr BP (median age with 2 sigma range of 8198-8270) and 8258 Cal. yr BP (median age with 2 sigma range of 8198-8270), respectively. The indistinguishable ages from these two peat layers, together with the diagnostic stratigraphic features, confirms that sea-level rise was likely instantaneous. This new chronology of the final LAO drainage is similar to the timings of the onset of the 8.2 ka event determined from high-resolution studies of Greenland ice cores and an Omani stalagmite, suggesting an instantaneous ocean-atmospheric system response to freshwater forcing, consistent with model predictions.

  17. Strong ground motion generated by controlled blasting experiments and mining induced seismic events recorded underground at deep level mines in South Africa

    NASA Astrophysics Data System (ADS)

    Milev, A.; Selllers, E.; Skorpen, L.; Scheepers, L.; Murphy, S.; Spottiswoode, S. M.

    2011-12-01

    A number of simulated rockbursts were conducted underground at deep level gold mines in South Africa in order to estimate the rock mass response when subjected to strong ground motion. The rockbursts were simulated by means of large blasts detonated in solid rock close to the sidewall of a tunnel. The simulated rockbursts involved the design of the seismic source, seismic observations in the near and far field, high-speed video filming, a study of rock mass conditions such as fractures, joints, rock strength etc. Knowledge of the site conditions before and after the simulated rockbursts was also gained. The numerical models used in the design of the simulated rockbursts were calibrated by small blasts taking place at each experimental site. A dense array of shock type accelerometers was installed along the blasting wall to monitor the attenuation of the strong ground motion as a function of the distance from the source. The attenuation of peak particle velocities, was found to be proportional to R^-1.7. Special investigations were carried out to evaluate the mechanism and the magnitude of damage, as well as the support behaviour under excessive dynamic loading. The strong ground motion generated by mining induced seismic events was studied, as part of this work, not only to characterize the rock mass response, but also to estimate the site effect on the surface of the underground excavations. A stand-alone instrument especially designed for recording strong ground motions was used to create a large database of peak particle velocities measured on stope hangingwalls. A total number of 58 sites located in stopes where the Carbon Leader Reef, Ventersdorp Contact Reef, Vaal Reef and Basal Reef are mined, were monitored. The peak particle velocities were measured at the surface of the excavations to identify the effect of the free surface and the fractures surrounding the underground mining. Based on these measurements the generally accepted velocity criterion of 3 m

  18. Phenotyping for patient safety: algorithm development for electronic health record based automated adverse event and medical error detection in neonatal intensive care

    PubMed Central

    Li, Qi; Melton, Kristin; Lingren, Todd; Kirkendall, Eric S; Hall, Eric; Zhai, Haijun; Ni, Yizhao; Kaiser, Megan; Stoutenborough, Laura; Solti, Imre

    2014-01-01

    Background Although electronic health records (EHRs) have the potential to provide a foundation for quality and safety algorithms, few studies have measured their impact on automated adverse event (AE) and medical error (ME) detection within the neonatal intensive care unit (NICU) environment. Objective This paper presents two phenotyping AE and ME detection algorithms (ie, IV infiltrations, narcotic medication oversedation and dosing errors) and describes manual annotation of airway management and medication/fluid AEs from NICU EHRs. Methods From 753 NICU patient EHRs from 2011, we developed two automatic AE/ME detection algorithms, and manually annotated 11 classes of AEs in 3263 clinical notes. Performance of the automatic AE/ME detection algorithms was compared to trigger tool and voluntary incident reporting results. AEs in clinical notes were double annotated and consensus achieved under neonatologist supervision. Sensitivity, positive predictive value (PPV), and specificity are reported. Results Twelve severe IV infiltrates were detected. The algorithm identified one more infiltrate than the trigger tool and eight more than incident reporting. One narcotic oversedation was detected demonstrating 100% agreement with the trigger tool. Additionally, 17 narcotic medication MEs were detected, an increase of 16 cases over voluntary incident reporting. Conclusions Automated AE/ME detection algorithms provide higher sensitivity and PPV than currently used trigger tools or voluntary incident-reporting systems, including identification of potential dosing and frequency errors that current methods are unequipped to detect. PMID:24401171

  19. FAST User Guide

    NASA Technical Reports Server (NTRS)

    Walatka, Pamela P.; Clucas, Jean; McCabe, R. Kevin; Plessel, Todd; Potter, R.; Cooper, D. M. (Technical Monitor)

    1994-01-01

    The Flow Analysis Software Toolkit, FAST, is a software environment for visualizing data. FAST is a collection of separate programs (modules) that run simultaneously and allow the user to examine the results of numerical and experimental simulations. The user can load data files, perform calculations on the data, visualize the results of these calculations, construct scenes of 3D graphical objects, and plot, animate and record the scenes. Computational Fluid Dynamics (CFD) visualization is the primary intended use of FAST, but FAST can also assist in the analysis of other types of data. FAST combines the capabilities of such programs as PLOT3D, RIP, SURF, and GAS into one environment with modules that share data. Sharing data between modules eliminates the drudgery of transferring data between programs. All the modules in the FAST environment have a consistent, highly interactive graphical user interface. Most commands are entered by pointing and'clicking. The modular construction of FAST makes it flexible and extensible. The environment can be custom configured and new modules can be developed and added as needed. The following modules have been developed for FAST: VIEWER, FILE IO, CALCULATOR, SURFER, TOPOLOGY, PLOTTER, TITLER, TRACER, ARCGRAPH, GQ, SURFERU, SHOTET, and ISOLEVU. A utility is also included to make the inclusion of user defined modules in the FAST environment easy. The VIEWER module is the central control for the FAST environment. From VIEWER, the user can-change object attributes, interactively position objects in three-dimensional space, define and save scenes, create animations, spawn new FAST modules, add additional view windows, and save and execute command scripts. The FAST User Guide uses text and FAST MAPS (graphical representations of the entire user interface) to guide the user through the use of FAST. Chapters include: Maps, Overview, Tips, Getting Started Tutorial, a separate chapter for each module, file formats, and system

  20. Tropical warming and intermittent cooling during the Cenomanian/Turonian oceanic anoxic event 2: Sea surface temperature records from the equatorial Atlantic

    NASA Astrophysics Data System (ADS)

    Forster, Astrid; Schouten, Stefan; Moriya, Kazuyoshi; Wilson, Paul A.; Sinninghe Damsté, Jaap S.

    2007-03-01

    Oceanic anoxic event 2 (OAE-2) occurring during the Cenomanian/Turonian (C/T) transition is evident from a globally recognized positive stable carbon isotopic excursion and is thought to represent one of the most extreme carbon cycle perturbations of the last 100 Myr. However, the impact of this major perturbation on and interaction with global climate remains unclear. Here we report new high-resolution records of sea surface temperature (SST) based on TEX86 and δ18O of excellently preserved planktic foraminifera and stable organic carbon isotopes across the C/T transition from black shales located offshore Suriname/French Guiana (Demerara Rise, Ocean Drilling Program Leg 207 Site 1260) and offshore Senegal (Cape Verde Basin, Deep Sea Drilling Project Leg 41 Site 367). At Site 1260, where both SST proxy records can be determined, a good match between conservative SST estimates from TEX86 and δ18O is observed. We find that late Cenomanian SSTs in the equatorial Atlantic Ocean (≥33°C) were substantially warmer than today (˜27°-29°C) and that the onset of OAE-2 coincided with a rapid shift to an even warmer (˜35°-36°C) regime. Within the early stages of the OAE a marked (˜4°C) cooling to temperatures lower than pre-OAE conditions is observed. However, well before the termination of OAE-2 the warm regime was reestablished and persisted into the Turonian. Our findings corroborate the view that the C/T transition represents the onset of the interval of peak Cretaceous warmth. More importantly, they are consistent with the hypotheses that mid-Cretaceous warmth can be attributed to high levels of atmospheric carbon dioxide (CO2) and that major OAEs were capable of triggering global cooling through the negative feedback effect of organic carbon-burial-led CO2 sequestration. Evidently, however, the factors that gave rise to the observed shift to a warmer climate regime at the onset of OAE-2 were sufficiently powerful that they were only briefly counterbalanced

  1. North Caribbean neotectonic events: The Trans-Haitian fault system. Tertiary record of an oblique transcurrent shear zone uplifted in Hispaniola

    NASA Astrophysics Data System (ADS)

    Pubellier, M.; Vila, J.-M.; Boisson, D.

    1991-08-01

    The left-lateral relative motion between the Caribbean and the North American plates has previously been inferred as occurring along a fault zone located north of Hispaniola. East of the northern Dominican Republic, a relatively linear fracture zone (the Septentrional Fault Zone, SFZ) extends into the Puerto Rico subduction zone. Similarly, south of Haiti, the trace of the inactive Enriquillo-Plantain Garden Fault Zone (EPGFZ) extends into the Muertos Trench and may represent a major fault along the plate boundary. Between these two major strike-slip fault systems, the central part of Haiti shows a diffuse fracture zone that trends N130. The chronology of deformation involves an initial Paleocene to Eocene suturing of allochthonous terranes, a Late Miocene development of a strong spaced cleavage within the late Paleocene to Late Miocene strata that overlap the terrane suture, and diffuse Pliocene to Pleistocene strike-slip faulting along traces that reactivate the older spaced cleavage planes. During the Pleistocene, basalts ranging in age from 0.4 to 1.3 Ma were extruded in pull-apart basins associated with N130-trending faults (antithetic features of the SFZ) and N30 normal faults (antecedent synthetic features of the SFZ). This event is coeval with the compression recorded at the Muertos-Beata collision front in the southwestern Dominican Republic. The most recent phase of tectonism involves strong uplifts and broad, open folding along NW-striking axes, which is consistent with the regional maximum deformation pattern predicted for E-W left-lateral shear along the North America—Caribbean plate boundary.

  2. A New Oceanic Anoxic Event 2 record from the Central North Atlantic at South East Newfoundland Ridge, IODP Expedition 342, Newfoundland Drifts

    NASA Astrophysics Data System (ADS)

    Junium, C. K.; Bornemann, A.; Bown, P. R.; Friedrich, O.; Moriya, K.; Kirtland Turner, S.; Whiteside, J. H.

    2013-12-01

    The recovery of Cretaceous, Cenomanian-Turonian black shales deposited during Oceanic Anoxic Event 2 (OAE 2) at Site U1407, South East Newfoundland Ridge (SENR), was an unexpected but fortuitous discovery that fills a gap in the pelagic Tethyan and North Atlantic geologic records. Drilling operations recovered the OAE sequence in all three holes drilled at Site U1407 defined initially on the basis of lithology and calcareous nannofossil biostratigraphy and confirmed by carbon isotope stratigraphy post-expedition. The SENR OAE 2 sequence is a classic chalk sequence punctuated by a prominent black band. Prior to OAE 2, greenish white pelagic carbonate is interrupted by thin, 2 to 5 cm thick organic-rich, gray calcareous clays. A sharp transition from greenish-white chalk to carbonate-poor sediments marks the occurrence of the organic carbon-rich black band. Within the black band are finely laminated to massive, pyritic black shales and laminated gray clays that are relatively organic carbon-lean, free of preserved benthic foraminifera and rich in radiolarians. Finely laminated greenish-gray marls overlay the black band and grade into approximately 1 meter of greenish white chalks with common 1cm chert layers and nodules. The remainder of the Turonian sequence is characterized by a notable transition to pink chalks. The thickness of the black band ranges from 15-40 cm between Holes A through C. The differences in the thickness of beds between Holes is due in part to drilling disturbances and mass wasting indicated by slump features in the overlying Turonian strata. Core scanning XRF and carbon isotopes can help resolve the nature of these differences and inform future sampling and study. Carbonate and organic carbon isotopes reveal that the δ13C excursion marking the initiation of OAE 2 is below the base of the black band. At U1407A the δ13C rise is immediately below (3 cm) the black shale, with δ13C maxima in the black band. At U1407C the initial δ13C rise is

  3. Deformation History of the Haymana Basin: Structural Records of Closure-Collision and Subsequent Convergence (Indentation) Events at the North-Central Neotethys (Central Anatolia, Turkey)

    NASA Astrophysics Data System (ADS)

    Gülyüz, Erhan; Özkaptan, Murat; Kaymakcı, Nuretdin

    2016-04-01

    Gondwana- (Tauride Platfrom and Kırşehir Block) and Eurasia (Pontides) - derived continental blocks bound the Haymana basin, in the south and north, respectively. Boundaries between these blocks are signed by İzmir-Ankara-Erzincan and debatable Intra-Tauride Suture zones which are straddled by the Haymana Basin in the region. In this regard, deformation recorded in the upper Cretaceous to middle Eocene deposits of the basin is mainly controlled by the relative movements of these blocks. Therefore, understanding the structural evolution of the Haymana Basin in a spatio-temporal concept is crucial to shed some light on some debatable issues such as ; (1) timing of late stage subduction histories of various branches of Neotethys and subsequent collision events, (2) effects of post-collisional tectonic activity in the Haymana region. Fault kinematic analyses (based on 623 fault-slip data from 73 stations) indicate that the basin was subjected to initially N-S to NNE-SSW extension until middle Paleocene and then N-S- to NNE-SSW- directed continuous compression and coeval E-W to ESE-WNW extension up to middle Miocene. These different deformation phases correspond to the fore-arc (closure) and foreland (collision and further convergence) stages of the basin. Additionally, fold analyses (based on 1017 bedding attitudes) and structural mapping studies show that development of folds and major faults are coeval and they can be explained by principle stress orientations of the second deformation phase. The Haymana basin is, based on the trends of E-W- and WNW-ESE- directed structures at the south-eastern and the north-western parts of the basin, respectively, divided into two structural segments. The balanced cross-sections also indicate ~4% and ~25% shortening at the north-western and south-eastern segments, respectively. The differences in amounts of shortenings are explained by reduce in effectiveness zone of basin-bounding thrust faults towards west. On the other hand

  4. Layered Fault Rocks Below the West Salton Detachment Fault (WSDF), CA Record Multiple Seismogenic? Slip Events and Transfer of Material to a Fault Core

    NASA Astrophysics Data System (ADS)

    Axen, G. J.; Luther, A. L.; Selverstone, J.; Mozley, P.

    2011-12-01

    -size distributions reflect constrained comminution and shear localization (slopes of ~3-3.5 on log-log plots of grain size vs. no. of grains > grain size). The LCs require episodic slip events that probably record dozens of seismic cycles. Foliation likely records post- or interseismic creep. Geometric complexities among the WSDF footwall splays presumably caused episodic dilation that allowed accumulation and folding of the LCs. Mechanical processes dominated over chemical processes. A key question is why the LCs apparently were stronger than the overlying granodiorite, leading to formation of new LC layers rather than significant reworking of older layers.

  5. Diamond detector for high rate monitors of fast neutrons beams

    SciTech Connect

    Giacomelli, L.; Rebai, M.; Cippo, E. Perelli; Tardocchi, M.; Fazzi, A.; Andreani, C.; Pietropaolo, A.; Frost, C. D.; Rhodes, N.; Schooneveld, E.; Gorini, G.

    2012-06-19

    A fast neutron detection system suitable for high rate measurements is presented. The detector is based on a commercial high purity single crystal diamond (SDD) coupled to a fast digital data acquisition system. The detector was tested at the ISIS pulsed spallation neutron source. The SDD event signal was digitized at 1 GHz to reconstruct the deposited energy (pulse amplitude) and neutron arrival time; the event time of flight (ToF) was obtained relative to the recorded proton beam signal t{sub 0}. Fast acquisition is needed since the peak count rate is very high ({approx}800 kHz) due to the pulsed structure of the neutron beam. Measurements at ISIS indicate that three characteristics regions exist in the biparametric spectrum: i) background gamma events of low pulse amplitudes; ii) low pulse amplitude neutron events in the energy range E{sub dep}= 1.5-7 MeV ascribed to neutron elastic scattering on {sup 12}C; iii) large pulse amplitude neutron events with E{sub n} < 7 MeV ascribed to {sup 12}C(n,{alpha}){sup 9}Be and 12C(n,n')3{alpha}.

  6. Adapting machine learning techniques to censored time-to-event health record data: A general-purpose approach using inverse probability of censoring weighting.

    PubMed

    Vock, David M; Wolfson, Julian; Bandyopadhyay, Sunayan; Adomavicius, Gediminas; Johnson, Paul E; Vazquez-Benitez, Gabriela; O'Connor, Patrick J

    2016-06-01

    Models for predicting the probability of experiencing various health outcomes or adverse events over a certain time frame (e.g., having a heart attack in the next 5years) based on individual patient characteristics are important tools for managing patient care. Electronic health data (EHD) are appealing sources of training data because they provide access to large amounts of rich individual-level data from present-day patient populations. However, because EHD are derived by extracting information from administrative and clinical databases, some fraction of subjects will not be under observation for the entire time frame over which one wants to make predictions; this loss to follow-up is often due to disenrollment from the health system. For subjects without complete follow-up, whether or not they experienced the adverse event is unknown, and in statistical terms the event time is said to be right-censored. Most machine learning approaches to the problem have been relatively ad hoc; for example, common approaches for handling observations in which the event status is unknown include (1) discarding those observations, (2) treating them as non-events, (3) splitting those observations into two observations: one where the event occurs and one where the event does not. In this paper, we present a general-purpose approach to account for right-censored outcomes using inverse probability of censoring weighting (IPCW). We illustrate how IPCW can easily be incorporated into a number of existing machine learning algorithms used to mine big health care data including Bayesian networks, k-nearest neighbors, decision trees, and generalized additive models. We then show that our approach leads to better calibrated predictions than the three ad hoc approaches when applied to predicting the 5-year risk of experiencing a cardiovascular adverse event, using EHD from a large U.S. Midwestern healthcare system.

  7. Adapting machine learning techniques to censored time-to-event health record data: A general-purpose approach using inverse probability of censoring weighting.

    PubMed

    Vock, David M; Wolfson, Julian; Bandyopadhyay, Sunayan; Adomavicius, Gediminas; Johnson, Paul E; Vazquez-Benitez, Gabriela; O'Connor, Patrick J

    2016-06-01

    Models for predicting the probability of experiencing various health outcomes or adverse events over a certain time frame (e.g., having a heart attack in the next 5years) based on individual patient characteristics are important tools for managing patient care. Electronic health data (EHD) are appealing sources of training data because they provide access to large amounts of rich individual-level data from present-day patient populations. However, because EHD are derived by extracting information from administrative and clinical databases, some fraction of subjects will not be under observation for the entire time frame over which one wants to make predictions; this loss to follow-up is often due to disenrollment from the health system. For subjects without complete follow-up, whether or not they experienced the adverse event is unknown, and in statistical terms the event time is said to be right-censored. Most machine learning approaches to the problem have been relatively ad hoc; for example, common approaches for handling observations in which the event status is unknown include (1) discarding those observations, (2) treating them as non-events, (3) splitting those observations into two observations: one where the event occurs and one where the event does not. In this paper, we present a general-purpose approach to account for right-censored outcomes using inverse probability of censoring weighting (IPCW). We illustrate how IPCW can easily be incorporated into a number of existing machine learning algorithms used to mine big health care data including Bayesian networks, k-nearest neighbors, decision trees, and generalized additive models. We then show that our approach leads to better calibrated predictions than the three ad hoc approaches when applied to predicting the 5-year risk of experiencing a cardiovascular adverse event, using EHD from a large U.S. Midwestern healthcare system. PMID:26992568

  8. A 38,000-year record of floods and debris flows in the Ilo region of southern Peru and its relation to El Niño events and great earthquakes

    USGS Publications Warehouse

    Keefer, David K.; Moseley, Michael E.; DeFrance, Susan D.

    2003-01-01

    Previous work throughout the Ilo region of south coastal Peru has documented the existence of flood and debris-flow deposits produced by two El Niño events evidently much more severe than any in recent history. These two events have been dated to ca. AD 1300–1400 and AD 1607–08. The Late Pleistocene to Holocene record of older sedimentary deposits in this region is dominated by flood and debris-flow deposits of similar scale. These older deposits have been described and dated from three coastal, alluvial-fan sites. These deposits, which are as old as 38 200 years, are dominated by massive debris-flow deposits, several tens of cm thick, typically composed of cobble- and boulder-sized clasts in a matrix of silty sand, with characteristics indicating generation by heavy rainfall in an arid environment. Twenty-two radiocarbon dates and a single infrared-stimulated luminescence date show that particularly severe El Niño events occurred throughout the Late Pleistocene and two of three divisions of the Holocene with significantly different frequencies. The period of greatest activity was during the Early Holocene when at least six such events took place during a period of ca. 3600 years, beginning near the end of the Younger Dryas ca. 12 000 years ago. One of these events produced a debris flow that may have caused abandonment of the Paleo-Indian site at Quebrada Tacahuay, one of the oldest on the Andean coast. No severe events took place during the Middle Holocene between ca. 8400 and 5300 years ago, when a wide variety of other paleoclimate proxy records indicate that the El Niño–Southern Oscillation regime was particularly weak. Since ca. 5300 years ago, four of these severe events have taken place. The Late Pleistocene sequence is constrained by only two dates, which indicate that at least ten severe events took place between ca. 38 200 and 12 900 years ago. Mechanisms probably responsible for generating these large-scale deposits include: (1)

  9. Avian mortality events in the United States caused by anticholinesterase pesticides: a retrospective summary of National Wildlife Health Center records from 1980 to 2000

    USGS Publications Warehouse

    Fleischli, Margaret A.; Franson, J.C.; Thomas, N.J.; Finley, D.L.; Riley, W.

    2004-01-01

    We reviewed the U.S. Geological Survey National Wildlife Health Center (NWHC) mortality database from 1980 to 2000 to identify cases of poisoning caused by organophosphorus and carbamate pesticides. From the 35,022 cases from which one or more avian carcasses were submitted to the NWHC for necropsy, we identified 335 mortality events attributed to anticholinesterase poisoning, 119 of which have been included in earlier reports. Poisoning events were classified as confirmed (n = 205) when supported by findings of ≥50% inhibition of cholinesterase (ChE) activity in brain tissue and the detection of a specific pesticide in the gastrointestinal contents of one or more carcasses. Suspected poisonings (n = 130) were defined as cases where brain ChE activity was ≥50% inhibited or a specific pesticide was identified in gastrointestinal contents. The 335 avian mortality events occurred in 42 states. Washington, Virginia, and Ohio had the highest frequency of events, with 24 (7.2%), 21 (6.3%), and 20 (6.0%) events, respectively. A total of 8877 carcasses of 103 avian species in 12 orders was recovered. Because carcass counts underestimate total mortality, this represents the minimum actual mortality. Of 24 different pesticides identified, the most frequent were famphur (n = 59; 18%), carbofuran (n = 52; 15%), diazinon (n = 40; 12%), and fenthion (n = 17; 5.1%). Falconiformes were reported killed most frequently (49% of all die-offs) but Anseriformes were found dead in the greatest numbers (64% of 8877 found dead). The majority of birds reported killed by famphur were Passeriformes and Falconiformes, with the latter found dead in 90% of famphur-related poisoning events. Carbofuran and famphur were involved in mortality of the greatest variety of species (45 and 33, respectively). Most of the mortality events caused by diazinon involved waterfowl.

  10. Increased oscillatory theta activation evoked by violent digital game events.

    PubMed

    Salminen, Mikko; Ravaja, Niklas

    2008-04-11

    The authors examined electroencephalographic (EEG) oscillatory responses to two violent events, the player character wounding and killing an opponent character with a gun, in the digital game James Bond 007: NightFire. EEG was recorded from 25 (16 male) right-handed healthy young adults. EEG data were segmented into one 1-s baseline epoch before each event and two 1-s epochs after event onset. Power estimates (microV(2)) were derived with the fast Fourier transform (FFT) for each artefact free event. Both of the studied events evoked increased occipital theta (4-6Hz) responses as compared to the pre-event baseline. The wounding event evoked also increased occipital high theta (6-8Hz) response and the killing event evoked low alpha (8-10Hz) asymmetry over the central electrodes, both relative to the pre-event baseline. The results are discussed in light of facial electromyographic and electrodermal activity responses evoked by these same events, and it is suggested that the reported EEG responses may be attributable to affective processes related to these violent game events. PMID:18325669

  11. Hydride VPE: the unexpected process for the fast growth of GaAs and GaN nanowires with record aspect ratio and polytypism-free crystalline structure

    NASA Astrophysics Data System (ADS)

    André, Yamina; Trassoudaine, Agnès.; Avit, Geoffrey; Lekhal, Kaddour; Ramdani, Mohammed R.; Leroux, Christine; Monier, Guillaume; Varenne, Christelle; Hoggan, Philip; Castelluci, Dominique; Bougerol, Catherine; Réveret, François; Leymarie, Joël.; Petit, Elodie; Dubrovskii, Vladimir G.; Gil, Evelyne

    2013-12-01

    Hydride Vapor Phase Epitaxy (HVPE) makes use of chloride III-Cl and hydride V-H3 gaseous growth precursors. It is known as a near-equilibrium process, providing the widest range of growth rates from 1 to more than 100 μm/h. When it comes to metal catalyst-assisted VLS (vapor-liquid-solid) growth, the physics of HVPE growth is maintained: high dechlorination frequency, high axial growth rate of nanowires (NWs) up to 170 μm/h. The remarkable features of NWs grown by HVPE are the untapered morphology with constant diameter and the stacking fault-free crystalline phase. Record pure zinc blende cubic phase for 20 μm long GaAs NWs with radii of 10 and 5 nm is shown. The absence of wurtzite phase in GaAs NWs grown by HVPE whatever the diameter is discussed with respect to surface energetic grounds and kinetics. Ni assisted, Ni-Au assisted and catalyst-free HVPE growth of wurtzite GaN NWs is also addressed. Micro-photoluminescence spectroscopy analysis revealed GaN nanowires of great optical quality, with a FWHM of 1 meV at 10 K for the neutral donor bound exciton transition.

  12. Consistently dated records from the Greenland GRIP, GISP2 and NGRIP ice cores for the past 104 ka reveal regional millennial-scale δ18O gradients with possible Heinrich event imprint

    NASA Astrophysics Data System (ADS)

    Seierstad, Inger K.; Abbott, Peter M.; Bigler, Matthias; Blunier, Thomas; Bourne, Anna J.; Brook, Edward; Buchardt, Susanne L.; Buizert, Christo; Clausen, Henrik B.; Cook, Eliza; Dahl-Jensen, Dorthe; Davies, Siwan M.; Guillevic, Myriam; Johnsen, Sigfús J.; Pedersen, Desirée S.; Popp, Trevor J.; Rasmussen, Sune O.; Severinghaus, Jeffrey P.; Svensson, Anders; Vinther, Bo M.

    2014-12-01

    We present a synchronization of the NGRIP, GRIP and GISP2 ice cores onto a master chronology extending back to 104 ka before present, providing a consistent chronological framework for these three Greenland records. The synchronization aligns distinct peaks in volcanic proxy records and other impurity records (chemo-stratigraphic matching) and assumes that these layers of elevated impurity content represent the same, instantaneous event in the past at all three sites. More than 900 marker horizons between the three cores have been identified and our matching is independently confirmed by 24 new and previously identified volcanic ash (tephra) tie-points. Using the reference horizons, we transfer the widely used Greenland ice-core chronology, GICC05modelext, to the two Summit cores, GRIP and GISP2. Furthermore, we provide gas chronologies for the Summit cores that are consistent with the GICC05modelext timescale by utilizing both existing and new gas data (CH4 concentration and δ15N of N2). We infer that the accumulation contrast between the stadial and interstadial phases of the glacial period was ˜10% greater at Summit compared to at NGRIP. The δ18O temperature-proxy records from NGRIP, GRIP, and GISP2 are generally very similar and display synchronous behaviour at climate transitions. The δ18O differences between Summit and NGRIP, however, changed slowly over the Last Glacial-Interglacial cycle and also underwent abrupt millennial-to-centennial-scale variations. We suggest that this observed latitudinal δ18O gradient in Greenland during the glacial period is the result of 1) relatively higher degree of precipitation with a Pacific signature at NGRIP, 2) increased summer bias in precipitation at Summit, and 3) enhanced Rayleigh distillation due to an increased source-to-site distance and a potentially larger source-to-site temperature gradient. We propose that these processes are governed by changes in the North American Ice Sheet (NAIS) volume and North

  13. Unravelling a long-term multi-event thermal record in the cratonic interior of southern Finland through apatite fission track thermochronology

    NASA Astrophysics Data System (ADS)

    Murrell, G. R.; Andriessen, P. A. M.

    Apatite fission track thermochronology (AFTT) has been applied to the Precambrian basement rocks of southern Finland in an attempt to detect within the long-term thermal history, thermal manifestations in the cratonic interior of tectonic events at the craton margin. The likely subtle magnitude of these manifestations means that AFTT is a useful technique for such a study due to its low temperature sensitivity. A total of 10 samples have been analysed, generating AFTT ages, length statistics and thermal models. Ages range from 313 ± 22 to 848 ± 60 Ma and mean track lengths range from 11.0 ± 1.6 to 13.3 ± 1.8 μm. The data suggests the presence of thermal overprinting of an earlier cooling event. Thermal modelling produces similar results for all samples and typically contains the following major events: (1) two phases of Late-Proterozoic cooling, (2) Late-Silurian re-heating, (3) Cenozoic cooling. The first phase of Late-Proterozoic cooling is interpreted to be due to aulacogen inversion as a result of stress propagation from the collisional tectonics of the Sveconorwegian orogeny. The second phase is discussed in relation to passive margin formation and possible asthenospheric diaper induced relief and exhumation. The Late-Silurian re-heating coincides in time with a proposed Caledonian foreland basin. The Cenozoic cooling is interpreted to represent the latest exposure resulting from North Atlantic Margin formation induced uplift and associated denudation.

  14. Combined oxygen- and carbon-isotope records through the Early Jurassic: multiple global events and two modes of carbon-cycle/temperature coupling

    NASA Astrophysics Data System (ADS)

    Hesselbo, S. P.; Korte, C.

    2010-12-01

    The Jurassic comprises some 55 million years of Earth history. However, within the Jurassic, only one major environmental change (hyperthermal) event is really well known - the Early Toarcian Oceanic Anoxic Event (OAE) at ~183 Ma - and until very recently the extent to which the accompanying environmental changes were global has been strongly debated. Nevertheless, partly as a result of the international effort to define Global Stratotype Sections and Points (GSSPs), much more is now being discovered about environmental changes taking place at and around the other Jurassic Age (Stage) boundaries, to the extent that meaningful comparisons between these events can begin to be made. Here we present new carbon and oxygen isotope data from mollusks (bivalves and belemnites) and brachiopods collected through the marine Early Jurassic succession of NE England, including the Sinemurian-Plienbachian boundary GSSP. All materials have been screened by chemical analysis and scanning electron microscopy to check for diagenetic alteration. Analysis of carbon isotopes from marine calcite is supplemented by analysis of carbon-isotope values from fossil wood collected through the same section. It is demonstrated that both long-term and short-term carbon-isotope shifts from the UK Early Jurassic represent global changes in carbon cycle balances. The Sinemurian-Pliensbachian boundary event is an event of global significance and shows several similarities to the Toarcian OAE (relative sea-level change, carbon-isotope signature), but also some significant contrasts (oxygen-isotope based paleotemperatures which provide no evidence for warming). Significant contrast in oxygen- and carbon-isotope co-variation also occurs on a long timescale. There appear to be two modes in the co-variation of carbon and oxygen isotopes through this time interval: mode 1 shows positive correlation and may be explained by conventional sources and sinks for carbon-dioxide; mode 2, representing negative

  15. The Annual Cosmic-Radiation Intensities 1391 - 2014; The Annual Heliospheric Magnetic Field Strengths 1391 - 1983, and Identification of Solar Cosmic-Ray Events in the Cosmogenic Record 1800 - 1983

    NASA Astrophysics Data System (ADS)

    McCracken, K. G.; Beer, J.

    2015-10-01

    The annual cosmogenic ^{10}Be ice-core data from Dye 3 and the North Greenland Ice-core Project (NGRIP), and neutron-monitor data, 1951 - 2014, are combined to yield a record of the annual cosmic-ray intensity, 1391 - 2014. These data were then used to estimate the intensity of the heliospheric magnetic field (HMF), 1391 - 1983. All of these annual data are provided in the Electronic Supplementary Material. Analysis of these annual data shows that there were significant impulsive increases in ^{10}Be production in the year following the very large solar cosmic-ray events of 1942, 1949, and 1956. There was an additional enhancement that we attribute to six high-altitude nuclear explosions in 1962. All of these enhancements result in underestimates of the strength of the HMF. An identification process is defined, resulting in a total of seven impulsive ^{10}Be events in the interval 1800 - 1942 prior to the first detection of a solar cosmic-ray event using ionization chambers. Excision of the ^{10}Be impulsive enhancements yields a new estimate of the HMF, designated B(PCR-2). Five of the seven ^{10}Be enhancements prior to 1941 are well correlated with the occurrence of very great geomagnetic storms. It is shown that a solar cosmic-ray event similar to that of 25 July 1946, and occurring in the middle of the second or third year of the solar cycle, may merge with the initial decreasing phase of the 11-year cycle in cosmic-ray intensity and be unlikely to be detected in the ^{10}Be data. It is concluded that the occurrence rate for solar energetic-particle (SEP) events such as that on 23 February 1956 is about seven per century, and that there is an upper limit to the size of solar cosmic-ray events.

  16. Language As Social Event.

    ERIC Educational Resources Information Center

    Harste, Jerome C.

    A taxonomy developed for the study of the growth and development of written language from the perspective of social event was tested with a group of 68 children, aged three to six years. The subjects were presented with a wide variety of environmental print messages (road signs, toys, fast food signs, and household products) and were questioned…

  17. Climatic stress events in the source region of modern man - Matching the last 20 ka of the Chew Bahir climate record with occupation history of adjacent refugia

    NASA Astrophysics Data System (ADS)

    Foerster, Verena; Vogelsang, Ralf; Junginger, Annett; Asrat, Asfawossen; Lamb, Henry F.; Viehberg, Finn; Trauth, Martin H.; Schaebitz, Frank

    2014-05-01

    A rapidly changing environment is considered an important driver not just for human evolution but also for cultural and technological innovation and migration. To evaluate the impact that climatic shifts on different timescales might have had on the living conditions of prehistoric humans is one of the cornerstones in current research, but continuous paleo-climate records in the vicinity of archaeological sites are still rare. As a contribution towards a better understanding of this human-climate interaction we here present a match between the last 20 ka of the just recently developed paleo-climate record from Chew Bahir in southern Ethiopia and the settlement history of adjacent possible refugia. The Chew Bahir basin, as a newly explored reliable climatic archive, lies in a biogeographically highly sensitive transition zone between the Main Ethiopian Rift and the Omo-Turkana basin and hence represents an ideal site to study climatic variability in the source region of modern man. The climatic history with a temporal resolution of up to 3 years is showing besides orbitally driven long-term transitions in and out of favourable living conditions several short abrupt excursions towards drier or wetter episodes. Comparing the frequency of archaeological findings as a parameter for human occupation to this close-by climate record that allows us to outline how complex the interplay between humans and environment during the last 20 ka really was, which dynamics might have been involved and which role the temporal dimension of environmental changes could have played for the adaption of humans.

  18. The potential ocean acidification event at the Triassic-Jurassic boundary: Constraining carbonate chemistry using the presence of corals and coral reefs in the fossil record

    NASA Astrophysics Data System (ADS)

    Martindale, R. C.; Berelson, W.; Corsetti, F. A.; Bottjer, D. J.; West, A.

    2011-12-01

    Ocean acidification associated with emplacement of the Central Atlantic Magmatic Province (CAMP) has been hypothesized as a kill mechanism for the Triassic-Jurassic (T-J) mass extinction (~200Ma), but few direct proxies for ancient ocean acidity are available. Here, we suggest that the presence of fossil corals and coral reefs can constrain palaeocean acidity. Modern scleractinian corals lose the ability to biomineralize a robust skeleton below aragonite saturation states (ΩArag) of 2 and modern shallow water coral reefs are only found in ΩArag > 3; we use these minima to constrain ancient ocean carbonate chemistry when corals or coral reefs are preserved in the fossil record. Atmospheric pCO2 reconstructions are combined with the coral ΩArag limitations to calculate the total dissolved inorganic carbon (TCO2) in the Late Triassic Ocean, which is a measure of the buffering capacity or ocean sensitivity to acidification. Our results suggest that Late Triassic TCO2 values were low to moderate (2000-3000 μmol/kg) such that the pCO2 increases across the T-J boundary would have depressed saturation state to the point where coral biomineralization would have been challenging (ΩArag < 2), likely resulting in the observed coral and reef gap in the fossil record. While the average pCO2 elevations recorded in stomatal and pedogenic proxies are not sufficient to cause complete carbonate undersaturation, modeled scenarios for CAMP-related T-J pCO2 increases suggest that aragonite undersaturation is plausible and in extreme cases calcite undersaturation is possible. Thus, a short but extreme acidification in an ocean with a low TCO2 concentration could occur and would satisfactorily explain the significant extinction of calcareous organisms, the coral gap, and possibly the T-J carbonate crisis.

  19. Tephra constraints on Rapid Climate Events (TRACE): precise correlation of marine and ice-core records during the last glacial period in the North Atlantic region

    NASA Astrophysics Data System (ADS)

    Davies, S. M.; Griggs, A. J.; Abbott, P. M.; Bourne, A. J.; Purcell, C. S.; Hall, I. R.; Scourse, J. D.

    2014-12-01

    Little has challenged our understanding of climate change more so than the abruptness with which large-scale shifts in temperature occurred during the last glacial period. Atmospheric temperature jumps occurring within decades over Greenland were closely matched by rapid changes in North Atlantic sea surface temperatures and major re-organisation of the deep ocean circulation. Although these climatic instabilities are well-documented in various proxy records, the causal mechanisms of such short-lived oscillations remain poorly understood, largely due to the dating uncertainties that prevent the integration of different archives. Synchronisation of palaeoclimate records on a common timescale is inherently problematic, and unravelling the lead/lag responses (hence cause and effect) between the Earth's climate components is currently beyond our reach. TRACE - a 5 year project funded by the European Research Council - exploits the use of microscopic traces of tephra deposits to precisely correlate the Greenland ice-cores with North Atlantic marine records. Here we draw upon examples of how these time-lines can be used to constrain the lead/lag responses between the atmospheric and oceanic systems during the last glacial period. High-resolution proxy data from North Atlantic marine cores MD04-2829CQ from the Rosemary Bank and MD04 2820CQ from the Goban Spur are integrated with the Greenland ice-cores according to the position of common tephra isochrons. These direct tie-lines allow us to focus in detail on the relative timing of rapid warming transitions between Greenland and the North Atlantic ocean during the last glacial period.

  20. Orbital control on carbon cycle alterations and hyperthermal events in a cooling world: the late Early to Mid Eocene record at Possagno (southern Alps, Italy)

    NASA Astrophysics Data System (ADS)

    Galeotti, Simone; Sprovieri, Mario; Moretti, Matteo; Rio, Domenico; Fornaciari, Eliana; Giusberti, Luca; Agnini, Claudia; Backman, Jan; Lanci, Luca; Luciani, Valeria

    2013-04-01

    The late Early Eocene to Middle Eocene ~50-45 Million years ago (Ma) time interval in the middle bathyal, pelagic/hemipelagic succession of the Western Tethys Possagno section (southern Alps, Veneto), contains several episodes of negative carbon isotope excursions (CIEs) and concomitant dissolution of carbonates. These episodes are superimposed on a long term global climate cooling that started at about 51 Ma following the Early Eocene Climatic Optimum (EECO). Spectral analysis indicates that CIEs and dissolution events are paced by orbital forcing, confirming the global significance of previous finding on the same interval from Western and Southern Atlantic and Equatorial Pacific sites. The frequency and magnitude of CIEs through time is controlled by long-term modulations of orbital parameters, including long eccentricity (400 kyr) and a 1.2 million year modulation. Highest frequency of events - at the orbital scale - is observed across the EECO, which provides an observational basis to validate theoretical models predicting a threshold effect resulting from orbital forcing superimposed on gradually changing mean global boundary conditions. The observation of the 1.2 million year beat (long-term modulation of obliquity) together with previously published observation of enhanced obliquity (41 kyr) forcing across major CIEs and dissolution intervals indicates that high latitude feedbacks to orbital forcing played a fundamental role in the emplacement of the hyperthermals. The observed orbital forcing signature closely match that of early Eocene hyperthermals, suggesting similar driving processes.

  1. An extended Cretaceous-Tertiary (K/T) stable isotope record. Implications for paleoclimate and the nature of the K/T boundary event

    NASA Technical Reports Server (NTRS)

    Dhondt, Steven

    1988-01-01

    In order to obtain a detailed single site record of marine productivity and temperature across the Cretaceous-Tertiary (K/T) boundary, both delta C-13 and delta O-18 values were measured in paired surface and deep water microfossil and nannofossil samples of mid-latitude South Atlantic Deep Sea Drilling Project (DSDP) Site 528. Additionally, the percent sedimentary carbonate content of the rock samples from which the analyzed fossil samples were taken, were determined. The analyzed interval spanned the last approximately 1 million years of the Cretaceous (the Abathomphalus mayaroensis foraminiferal zone) and the first approximately 9 million years of the Tertiary (the Paleocene). Paired samples were analyzed every 150 cm of the entire 165 m sampled interval (1 sample per recovered DSDP section), every 20 cm for 2.0 m below and 2.5 m above the K/T boundary, and every 0.25 cm immediately below, at, and above the K/T boundary clay. The Cretaceous-Tertiary boundary and earliest Paleocene record of DSDP Site 528 is marked by at least two strong decreases in the surface-to-deep delta C-13 gradient (one at the K/T boundary (66.4 mybp1) and one approximately 150,000 to 200,000 years later). Both of these decreases co-occur with radical decreases in percent carbonate content and appear to indicate not one, but two, strong decreases in marine primary productivity during the analyzed interval.

  2. Latest Paleocene benthic extinction event on the southern Tethyan shelf (Egypt): Foraminiferal stable isotopic (δ13C, δ18O) records

    NASA Astrophysics Data System (ADS)

    Schmitz, B.; Speijer, R. P.; Aubry, M.-P.

    1996-04-01

    The dramatic global extinction of 35% 50% of benthic foraminifera species in the deep sea in the latest Paleocene and associated negative excursions in δ13C and δ18O may be related to spreading of warm, saline bottom water from subtropical Tethyan shallow regions over the sea floor worldwide. Our study of neritic sections in Egypt shows that in the southern shallow Tethys, a prominent long-term change in bottom-water chemistry, sedimentation, and benthic foraminifera fauna was initiated at the time when the deep-sea benthic extinction event (BEE) took place. Bottom-water δ13C values on the Tethyan shelf show a sudden 3.0‰ negative shift at this event; however, contrary to the deep sea, in which the δ13C excursion was of short duration, Tethyan δ13C values did not fully return to preboundary values, but remained depressed by ˜1.5‰ for at least 1 m.y. The δ13C values at the Egyptian shelf during the BEE are much lower than would be expected if this was a source region for global deep water. The δ18O values indicate no significant change in bottom-water salinity or temperature at the BEE. The long-lasting environmental changes that began on the Egyptian shelf at the BEE may be related to, for example, gateway reorganization along the Tethyan seaway. Paleogeographic changes possibly also triggered a change in the loci of global deep-water formation; however, these loci must be sought in another part of the Tethys.

  3. Fast valve

    DOEpatents

    Van Dyke, William J.

    1992-01-01

    A fast valve is disclosed that can close on the order of 7 milliseconds. It is closed by the force of a compressed air spring with the moving parts of the valve designed to be of very light weight and the valve gate being of wedge shaped with O-ring sealed faces to provide sealing contact without metal to metal contact. The combination of the O-ring seal and an air cushion create a soft final movement of the valve closure to prevent the fast air acting valve from having a harsh closing.

  4. Fast valve

    DOEpatents

    Van Dyke, W.J.

    1992-04-07

    A fast valve is disclosed that can close on the order of 7 milliseconds. It is closed by the force of a compressed air spring with the moving parts of the valve designed to be of very light weight and the valve gate being of wedge shaped with O-ring sealed faces to provide sealing contact without metal to metal contact. The combination of the O-ring seal and an air cushion create a soft final movement of the valve closure to prevent the fast air acting valve from having a harsh closing. 4 figs.

  5. Lacustrine anoxic event 1 (LAE1) recorded by rock magnetism of Unit 1 of Qingshankou Formation, Late Cretaceous Songliao Basin in Northeast China

    NASA Astrophysics Data System (ADS)

    Li, H.; Zhang, S.; Zhao, K.; Wu, H.; Yang, T.

    2011-12-01

    Songliao Basin, located in northeastern China, is one of the biggest cretaceous lakes in Asia, with most completely developed cretaceous stratigraphy. Therefore, it is a key area to study cretaceous palaeontology evolution and paleoenvironmental changes. Especially, anoxic events and marine transgressional events have been the research focuses for a long time. The lacustrine anoxic event 1 (LAE1) has been reported to happen in Songliao Basin during the deposition of unit 1 of Qingshankou Formation (K2qn1). In this study, K2qn1 was sampled from China Cretaceous Continental Scientific Drilling-Songke Ι (CCSD-SK-Ι) south borehole. The K2qn1, from 1700 m to 1782.8 m in the well log, mainly consists black shale and mudstone. LAE1 is the section from 1750 m to 1775 m. Detailed rock magnetic measurements were conducted, including magnetic susceptibility (χ) and susceptibility of anhysteretic remanence (χARM), saturation isothermal remanence (SIRM), S-ratio (IRM-100mT/SIRM), medial destroyed field of ARM (MDFARM), and temperature-dependence of magnetic susceptibilities (χ/T curves), acquiring curves and reverse demagnetic curves of IRM and thermal demagnetization of ARM and SIRM and Lowrie experiment for selected samples. X-ray diffraction (XRD) was also carried out for selected samples. The acquiring curves and reverse demagnetic curves of typical specimens and the thermal demagnetization of ARM and SIRM and the Lowrie experiment confirm that the major remanence-carrier is soft magnetite. Results of χ/T curves indicate that: for some specimens, pyrite exists (Li and Zhang, 2005); for most specimens, their χ decreases slowly during heating, suggesting a dominant contribution from paramagnetic minerals. Results of XRD suggest that these paramagnetic minerals may be feldspar, kaolinite and pyrite. So paramagnetic clay minerals control χ of K2qn1; and more clay minerals may induce higher natural gamma ray (GR). Therefore, χ and GR should be positive. On the contrary

  6. Atmospheric Carbon Dioxide and its Relation to Carbon Cycle Perturbations During Ocean Anoxic Event 1d: A High Resolution Record From Dispersed Plant Cuticle

    NASA Astrophysics Data System (ADS)

    Richey, J. D.; Upchurch, G. R.; Joeckel, R.; Smith, J. J.; Ludvigson, G. A.; Lomax, B. H.

    2013-12-01

    Past geological greenhouse intervals are associated with Ocean Anoxic Events (OAEs), which result from an increase in marine primary productivity and/or an increase in the preservation of organic matter. The end point is widespread black shale deposition combined with a long-term atmospheric positive δ13C excursion and an increase in the burial of 12C. Some OAEs show a negative δ13C excursion preceding the positive excursion, indicating a perturbation in the global carbon cycle prior to the initiation of these events. The Rose Creek (RCP) locality, southeastern Nebraska, is the only known terrestrial section that preserves OAE1d (Cretaceous, Albian-Cenomanian Boundary) and has abundant charcoal and plant cuticle. These features allow for a combined carbon isotope and stomatal index (SI) analysis to determine both changes in the cycling between carbon pools (C isotope analysis) and changes in paleo-CO2 via changes in SI. Preliminary (and ongoing) SI data analysis using dispersed cuticle of Pandemophyllum kvacekii (an extinct Laurel) collected at 30 cm intervals indicate changes in SI consistent with changes in CO2. Fitting our samples to a published RCP δ13C profile, pre-excursion CO2 concentrations are high. CO2 decreases to lower concentrations in the basal 1.2 m of the RCP section, where δ13Cbulk shows a negative excursion and δ13Ccharcoal remains at pre-excursion values. CO2 concentrations become higher toward the top of the negative δ13C excursion, where δ13Cbulk and δ13Ccharcoal are at their most negative values, and drop as the negative carbon excursion terminates. Using published transfer functions, we estimate that pre-excursion CO2 concentrations were a maximum of 900 ppm. In the basal 1.2 m of RCP, CO2 drops to a maximum of 480 ppm, and rises to a maximum of 710 ppm near the top of the negative excursion. As δ13C values rise towards pre-excursion values, CO2 declines to a maximum of 400 ppm. The trend in SI is comparable to the trend in δ13

  7. Spontaneous Decoding of the Timing and Content of Human Object Perception from Cortical Surface Recordings Reveals Complementary Information in the Event-Related Potential and Broadband Spectral Change.

    PubMed

    Miller, Kai J; Schalk, Gerwin; Hermes, Dora; Ojemann, Jeffrey G; Rao, Rajesh P N

    2016-01-01

    The link between object perception and neural activity in visual cortical areas is a problem of fundamental importance in neuroscience. Here we show that electrical potentials from the ventral temporal cortical surface in humans contain sufficient information for spontaneous and near-instantaneous identification of a subject's perceptual state. Electrocorticographic (ECoG) arrays were placed on the subtemporal cortical surface of seven epilepsy patients. Grayscale images of faces and houses were displayed rapidly in random sequence. We developed a template projection approach to decode the continuous ECoG data stream spontaneously, predicting the occurrence, timing and type of visual stimulus. In this setting, we evaluated the independent and joint use of two well-studied features of brain signals, broadband changes in the frequency power spectrum of the potential and deflections in the raw potential trace (event-related potential; ERP). Our ability to predict both the timing of stimulus onset and the type of image was best when we used a combination of both the broadband response and ERP, suggesting that they capture different and complementary aspects of the subject's perceptual state. Specifically, we were able to predict the timing and type of 96% of all stimuli, with less than 5% false positive rate and a ~20ms error in timing. PMID:26820899

  8. Spontaneous Decoding of the Timing and Content of Human Object Perception from Cortical Surface Recordings Reveals Complementary Information in the Event-Related Potential and Broadband Spectral Change

    PubMed Central

    Miller, Kai J.; Schalk, Gerwin; Hermes, Dora; Ojemann, Jeffrey G.; Rao, Rajesh P. N.

    2016-01-01

    The link between object perception and neural activity in visual cortical areas is a problem of fundamental importance in neuroscience. Here we show that electrical potentials from the ventral temporal cortical surface in humans contain sufficient information for spontaneous and near-instantaneous identification of a subject’s perceptual state. Electrocorticographic (ECoG) arrays were placed on the subtemporal cortical surface of seven epilepsy patients. Grayscale images of faces and houses were displayed rapidly in random sequence. We developed a template projection approach to decode the continuous ECoG data stream spontaneously, predicting the occurrence, timing and type of visual stimulus. In this setting, we evaluated the independent and joint use of two well-studied features of brain signals, broadband changes in the frequency power spectrum of the potential and deflections in the raw potential trace (event-related potential; ERP). Our ability to predict both the timing of stimulus onset and the type of image was best when we used a combination of both the broadband response and ERP, suggesting that they capture different and complementary aspects of the subject’s perceptual state. Specifically, we were able to predict the timing and type of 96% of all stimuli, with less than 5% false positive rate and a ~20ms error in timing. PMID:26820899

  9. Extreme pointer years in tree-ring records of Central Spain as evidence of climatic events and the eruption of the Huaynaputina Volcano (Peru, 1600 AD)

    NASA Astrophysics Data System (ADS)

    Génova, M.

    2012-04-01

    The study of pointer years of numerous tree-ring chronologies of the central Iberian Peninsula (Sierra de Guadarrama) could provide complementary information about climate variability over the last 405 yr. In total, 64 pointer years have been identified: 30 negative (representing minimum growths) and 34 positive (representing maximum growths), the most significant of these being 1601, 1963 and 1996 for the negative ones, and 1734 and 1737 for the positive ones. Given that summer precipitation was found to be the most limiting factor for the growth of Pinus in the Sierra de Guadarrama in the second half of the 20th century, it is also an explanatory factor in almost 50% of the extreme growths. Furthermore, these pointer years and intervals are not evenly distributed throughout time. Both in the first half of the 17th and in the second half of 20th, they were more frequent and more extreme and these periods are the most notable for the frequency of negative pointer years in Central Spain. The interval 1600-1602 is of special significance, being one of the most unfavourable for tree growth in the centre of Spain, with 1601 representing the minimum index in the regional chronology. We infer that this special minimum annual increase was the effect of the eruption of Huaynaputina, which occurred in Peru at the beginning of 1600 AD. This is the first time that the effects of this eruption in the tree-ring records of Southern Europe have been demonstrated.

  10. Ice core δD(CH4) record precludes marine hydrate CH4 emissions at the onset of Dansgaard-Oeschger events

    NASA Astrophysics Data System (ADS)

    Bock, M.; Schmitt, J.; Möller, L.; Spahni, R.; Blunier, T.; Fischer, H.

    2010-12-01

    Air enclosures in polar ice cores represent the only direct paleoatmospheric archive (besides firn air) and show that atmospheric CH4 concentrations changed in concert with northern hemisphere temperature during both glacial/interglacial transitions as well as rapid climate changes (Dansgaard-Oeschger events). For stadials and interstadials during Marine Isotope Stage 3 concentration jumps of 100 - 200 ppbv within a few decades are observed. A concentration gradient with higher values in the northern versus the southern hemisphere during warm stages was reconstructed from ice core methane data from Greenland and Antarctica. This gradient indicates additional methane emissions during warm periods located in the northern hemisphere. However, the underlying processes for these changes are still not well understood. With tropical and boreal wetlands, biomass burning, thermokarst lakes, ruminants, termites, UV-induced emissions from organic matter and marine gas hydrates all contributing to the natural atmospheric CH4 level, an unambiguous source attribution remains difficult. Also changes in the methane sinks can modify the tropospheric CH4 budget, as trace gases like volatile organic compounds are competing for the major reactant - the OH radical. Additionally, the changing global atmospheric methane concentration itself feeds back on its lifetime. Together with the CH4 interhemispheric gradient, stable hydrogen and carbon isotopic studies on methane (δD(CH4) and δ13CH4) in ice cores allow to constrain individual CH4 source/sink changes. Here we present clear evidence from the North Greenland Ice Core Project ice core based on the hydrogen isotopic composition of methane δD(CH4) that clathrates did not cause atmospheric methane concentration to rise at the onset of Dansgaard-Oeschger (DO) events 7 and 8 (34 - 41 kilo years before present), however, we can not exclude that they played a minor role during and at the end of an interstadial. Box modeling supports

  11. Deteriorating haze situation and the severe haze episode during December 18-25 of 2013 in Xi'an, China, the worst event on record

    NASA Astrophysics Data System (ADS)

    Liu, Xiaodong; Hui, Ying; Yin, Zhi-Yong; Wang, Zhaosheng; Xie, Xiaoning; Fang, Jiangang

    2016-07-01

    Frequent occurrence of haze weather has been considered an urgent environmental problem in China and has attracted much attention worldwide in recent years. In this study, we examined the trend in the occurrence of haze days based on horizontal visibility in Xi'an, a major city in central China, since 2000. There were 49 haze days per year on average in Xi'an during 2000-2013, and the number of haze days has increased significantly since 2008, reaching 102 days in 2013. December is the month of the highest frequency of occurrence. During December 18-25 of 2013, the longest-lasting and most severe haze event in the recent decades occurred. The 8-day mean visibility in Xi'an was only 2.5 km with 5 days below 2 km. The mean air quality index in Xi'an during this period was 486.5, and in four of those days, it reached or exceeded the index's upper limit of 500. The exceptionally high level of PM2.5 concentration was inferred as the main reason of this severe haze episode. The local weather conditions were characterized by weak winds, enhanced atmospheric stability, and high relative humidity. Strong mid-tropospheric zonal flows in combination with weakened East Asian winter monsoon limited the cold air invasion from the higher latitudes, creating a condition of low pressure gradients in the lower troposphere and near the surface for a large region in central and eastern China. With high background emission levels, the suppressed dispersion of air pollutants eventually caused this severe haze episode affecting a large region in China.

  12. Extreme pointer years in tree-ring records of Central Spain as evidence of volcanic eruptions (Huaynaputina, Peru, 1600 AC) and other climatic events

    NASA Astrophysics Data System (ADS)

    Génova, M.

    2011-12-01

    The study of pointer years based on the numerous tree-ring chronologies of the central Iberian Peninsula (Sierra de Guadarrama) could provide complementary information about climate variability over the last 405 years. In total, 64 pointer years have been identified: 30 negative (representing minimum growths) and 34 positive (representing maximum growths), the most significant of these being 1601, 1963 and 1996 for the negative ones, and 1734 and 1737 for the positive ones. Given that summer precipitation has been the most incident factor in the general variability of growth of Pinus in the Sierra de Guadarrama in the second half of the 20th century, it is also an explanatory factor in almost 50% of the extreme growths. Furthermore, the data show that there has been variability over the centuries in the distribution of the frequencies of pointer years and intervals. The first half of the 17th century, together with the second half of the 20th century, constitute the two most notable periods for the frequency of negative pointer years in Central Spain. This variability was sufficiently notable to affirm that, both in the 17th and 20th centuries, the macroclimatic anomalies that affected growth were more frequent and more extreme than in the other two centuries analysed. The period 1600-1602 is of special significance, being one of the most unfavourable for tree growth in the centre of Spain, with 1601 representing the minimum index in the regional chronology. It is possible to infer that these phenomena are the effect of the eruption of Huaynaputina, which occurred in Peru at the beginning of 1600 AD. This is the first time that the effects of this eruption in the tree-ring records of central and southern Europe have been demonstrated.

  13. Isorenieratane record in black shales from the Paris Basin, France: Constraints on recycling of respired CO2 as a mechanism for negative carbon isotope shifts during the Toarcian oceanic anoxic event

    NASA Astrophysics Data System (ADS)

    van Breugel, Yvonne; Baas, Marianne; Schouten, Stefan; Mattioli, Emanuela; Sinninghe Damsté, Jaap S.

    2006-12-01

    The prominent negative stable carbon isotope excursion in both carbonate and organic carbon recorded in organic-rich sediments deposited during the Toarcian oceanic anoxic event (OAE) has commonly been explained by recycling of 13C-depleted CO2 (the so-called Küspert model). More recently, the massive release of 13C-depleted methane or other forms of 13C-depleted carbon was also proposed to account for the observed negative δ13C excursions in organic carbon of terrigenous as well as of marine origin. The occurrence of diagenetic products of the carotenoid isorenieratene (isorenieratane and other aryl isoprenoids) in Toarcian black shales has been regarded as supporting evidence for the Küspert hypothesis as they point to strong stratification of the epicontinental seas. A section of a drill core straddling the Toarcian of the Paris Basin (Cirfontaine-en-Ornois) contained intact isorenieratane, providing evidence that photosynthetic green sulphur bacteria were present at the time of deposition, even prior to the OAE. However, the isorenieratane abundances are very low in the section where the negative δ13C excursion in organic carbon and phytane, a chemical fossil derived from chlorophyll, occurs. The abundance of the isorenieratene derivatives increases, once the δ13C records have shifted to more positive values. The δ13C of isorenieratane (generally circa -13.1 ± 0.5 ‰) indicates that the respired CO2 contribution at the chemocline was low and is thus not likely to be the main cause of the prominent up to 7‰ negative δ13C shift recorded in Toarcian organic carbon records.

  14. Effects of rupture directivity on ground motions and macroseismic intensities. Study of a Mw 4.1 earthquake recorded in the Alps and a Mw 6 event simulated using Empirical Green's Functions

    NASA Astrophysics Data System (ADS)

    Courboulex, F.; Dujardin, A.; Vallée, M.; Delouis, B.; Sira, C.; Honoré, L.; Thouvenot, F.; Deschamps, A.

    2013-12-01

    We first conduct a detailed analysis of a moderate earthquake in the French Alps (2012/02/26, Mw 4.1), that has been much more distinctly felt South of the event than North of it. This discrepancy was especially clear in the two large cities of Nice and Grenoble, both situated at 100 km from the epicenter. This observation was confirmed by ground motion measurements that were eight times larger in one city than in the other one, for the same site conditions. Using a time domain deconvolution between the broadband recordings of the mainshock and an aftershock used as empirical Green's Functions, we show that the rupture process of this event had a strong directivity effect towards a direction of N 155° +/- 5 on a ~ 2-km-long fault, detectable only at frequencies higher than 1 Hz. These fault size and direction are in good accordance with the location of the early aftershocks (4 days). The potential directivity effect of 232 aftershocks of the sequence has been also analyzed using their PGA values on broad band stations. We obtained that no preferential directivity effect can be evidenced on aftershocks. In a second step, we take advantage of the good recordings of this Mw=4.1 earthquake and its aftershocks to simulate the ground motions (and compute the macroseismic intensities using GMICES conversion relations) that would be generated by a larger event (Mw 6) occurring on the same fault. We consider separately the cases where the directivity effect is present or absent. The ground motions values (mainly PGA and PGV) and the macroseismic intensities are compared with the values predicted using Ground Motions Equations (GMPEs). The values obtained for the directive scenario on directive stations are almost always larger than the median values +1 sigma predicted by the GMPEs; this highlights the fact that a simple directivity effect of the rupture process can produce much larger damages than expected. Effects of rupture directivity on ground motions and macroseismic

  15. Dynamic Analysis of Event Histories.

    ERIC Educational Resources Information Center

    Tuma, Nancy Brandon; And Others

    1979-01-01

    Demonstrates the value of dynamic analysis of event-history data for the sociological study of change in categorical variables. An event history records dates of events that occur for some unit of analysis (i.e., an individual's marital or employment status, or outbreaks of riots or wars). (Author/AV)

  16. V-FASTR: THE VLBA FAST RADIO TRANSIENTS EXPERIMENT

    SciTech Connect

    Wayth, Randall B.; Tingay, Steven J.; Brisken, Walter F.; Deller, Adam T.; Majid, Walid A.; Thompson, David R.; Wagstaff, Kiri L.

    2011-07-10

    Recent discoveries of dispersed, non-periodic impulsive radio signals with single-dish radio telescopes have sparked significant interest in exploring the relatively uncharted space of fast transient radio signals. Here we describe V-FASTR, an experiment to perform a blind search for fast transient radio signals using the Very Long Baseline Array (VLBA). The experiment runs entirely in a commensal mode, alongside normal VLBA observations and operations. It is made possible by the features and flexibility of the DiFX software correlator that is used to process VLBA data. Using the VLBA for this type of experiment offers significant advantages over single-dish experiments, including a larger field of view, the ability to easily distinguish local radio-frequency interference from real signals, and the possibility to localize detected events on the sky to milliarcsecond accuracy. We describe our software pipeline, which accepts short integration ({approx} ms) spectrometer data from each antenna in real time during correlation and performs an incoherent dedispersion separately for each antenna, over a range of trial dispersion measures. The dedispersed data are processed by a sophisticated detector and candidate events are recorded. At the end of the correlation, small snippets of the raw data at the time of the events are stored for further analysis. We present the results of our event detection pipeline from some test observations of the pulsars B0329+54 and B0531+21 (the Crab pulsar).

  17. V-FASTR: The VLBA Fast Radio Transients Experiment

    NASA Astrophysics Data System (ADS)

    Wayth, Randall B.; Brisken, Walter F.; Deller, Adam T.; Majid, Walid A.; Thompson, David R.; Tingay, Steven J.; Wagstaff, Kiri L.

    2011-07-01

    Recent discoveries of dispersed, non-periodic impulsive radio signals with single-dish radio telescopes have sparked significant interest in exploring the relatively uncharted space of fast transient radio signals. Here we describe V-FASTR, an experiment to perform a blind search for fast transient radio signals using the Very Long Baseline Array (VLBA). The experiment runs entirely in a commensal mode, alongside normal VLBA observations and operations. It is made possible by the features and flexibility of the DiFX software correlator that is used to process VLBA data. Using the VLBA for this type of experiment offers significant advantages over single-dish experiments, including a larger field of view, the ability to easily distinguish local radio-frequency interference from real signals, and the possibility to localize detected events on the sky to milliarcsecond accuracy. We describe our software pipeline, which accepts short integration (~ ms) spectrometer data from each antenna in real time during correlation and performs an incoherent dedispersion separately for each antenna, over a range of trial dispersion measures. The dedispersed data are processed by a sophisticated detector and candidate events are recorded. At the end of the correlation, small snippets of the raw data at the time of the events are stored for further analysis. We present the results of our event detection pipeline from some test observations of the pulsars B0329+54 and B0531+21 (the Crab pulsar).

  18. Assessing the Record of Anoxic/Dysoxic Events in Lower Aptian Cupido/La Peña Formations, Northeastern Mexico

    NASA Astrophysics Data System (ADS)

    Maurrasse, F. J.; Barragan-Manzo, R.; Ponton, C.

    2008-05-01

    -thick each that are remarkably devoid of benthic foraminifers. They occur at 5. 72 m, 11.45m and 29.6 m, respectively, below the La Peña Fm. Variations within the Cupido Fm are consistent with fluctuating high- productivity, well-oxygenated neritic environment punctuated by development of hypoxic to anoxic bottom waters (Maurrasse et al., 2006). These recurrent episodes of severe oxygen depletion fall within the time interval that may be correlational with the infrajacent D. deshayesi to possibly the D. wessi zones in the Mediterranean ammonite biozonation scheme. We interpret these horizons to represent recurrent hypoxic to anoxic bottom conditions that are local expression of global forcing factors during Cretaceous greenhouse conditions that lead to well-defined OAE-1a and the subsequent anoxic events. Barragan-Manzo, R., and Maurrasse, F., (2008) Revista Mexicana de Ciencias Geologicas, v. 25, 1, p. 145-157. Barragan-Manzo, R., and Mendez-Franco, 2005, Towards a standard ammonite zonation for the Aptian (Lower Cretaceous) of northern Mexico. Revista Mexicana de Ciencias Geologicas, v. 22, 1, p. 39-47. Maurrasse, F. J-M. R., Barragan-Manzo, R., and Ponton, C. 2006, Cupido- La Peña Formations: High-Productivity to Super-Productivity during the Cretaceous Enhanced Greenhouse Conditions, GSA Abst.with programs v. 38, no 7, p. 491.

  19. Oxygen isotope perspective on crustal evolution on early Earth: A record of Precambrian shales with emphasis on Paleoproterozoic glaciations and Great Oxygenation Event

    NASA Astrophysics Data System (ADS)

    Bindeman, I. N.; Bekker, A.; Zakharov, D. O.

    2016-03-01

    We present stable isotope and chemical data for 206 Precambrian bulk shale and tillite samples that were collected mostly from drillholes on all continents and span the age range from 0.5 to 3.5 Ga with a dense coverage for 2.5-2.2 Ga time interval when Earth experienced four Snowball Earth glaciations and the irreversible rise in atmospheric O2. We observe significant, downward shift of several ‰ and a smaller range of δ18 O values (7 to 9‰) in shales that are associated with the Paleoproterozoic and, potentially, Neoproterozoic glaciations. The Paleoproterozoic samples consist of more than 50% mica minerals and have equal or higher chemical index of alteration than overlying and underlying formations and thus underwent equal or greater degrees of chemical weathering. Their pervasively low δ18 O and δD (down to - 85 ‰) values provide strong evidence of alteration and diagenesis in contact with ultra-low δ18 O glacial meltwaters in lacustrine, deltaic or periglacial lake (sikussak-type) environments associated with the Paleoproterozoic glaciations. The δDsilicate values for the rest of Precambrian shales range from -75 to - 50 ‰ and are comparable to those for Phanerozoic and Archean shales. Likewise, these samples have similar ranges in δ13Corg values (-23 to - 33 ‰ PDB) and Corg content (0.0 to 10 wt%) to Phanerozoic shales. Precambrian shales have a large range of δ18 O values comparable to that of the Phanerozoic shales in each age group and formation, suggesting similar variability in the provenance and intensity of chemical weathering, except for the earliest 3.3-3.5 Ga Archean shales, which have consistently lower δ18 O values. Moreover, Paleoproterozoic shales that bracket in age the Great Oxidation Event (GOE) overlap in δ18 O values. Absence of a step-wise increase in δ18 O and δD values suggests that despite the first-order change in the composition of the atmosphere, weathering cycle was not dramatically affected by the GOE at ∼2

  20. Tsunami Records on Seismometers

    NASA Astrophysics Data System (ADS)

    Allgeyer, S.; Cummins, P. R.

    2015-12-01

    Since the 2004 Sumatra event, observations of tsunamis have been recorded on a variety of geophysical sensors like tide gages, tilt meters and seismometers. Recent advances in tsunami simulations, that include mainly elastic loading, have quantified the interaction between the ocean and the surrounding seafloor, resulting in a better agreement between tsunami observations and simulation. This improvement in the modelling allows us to use tilt observations in the study of tsunami events. In this study, we will use seismic tilt derived observations for well-recorded events in order to provide a new approach to the study of past events.

  1. Solar extreme events

    NASA Astrophysics Data System (ADS)

    Hudson, Hugh S.

    2015-08-01

    Solar flares and CMEs have a broad range of magnitudes. This review discusses the possibility of “extreme events,” defined as those with magnitudes greater than have been seen in the existing historical record. For most quantitative measures, this direct information does not extend more than a century and a half into the recent past. The magnitude distributions (occurrence frequencies) of solar events (flares/CMEs) typically decrease with the parameter measured or inferred (peak flux, mass, energy etc. Flare radiation fluxes tend to follow a power law slightly flatter than S-2, where S represents a peak flux; solar particle events (SPEs) follow a still flatter power law up to a limiting magnitude, and then appear to roll over to a steeper distribution, which may take an exponential form or follow a broken power law. This inference comes from the terrestrial 14C record and from the depth dependence of various radioisotope proxies in the lunar regolith and in meteorites. Recently major new observational results have impacted our use of the relatively limited historical record in new ways: the detection of actual events in the 14C tree-ring records, and the systematic observations of flares and “superflares” by the Kepler spacecraft. I discuss how these new findings may affect our understanding of the distribution function expected for extreme solar events.

  2. Adaptive noise estimation and suppression for improving microseismic event detection

    NASA Astrophysics Data System (ADS)

    Mousavi, S. Mostafa; Langston, Charles A.

    2016-09-01

    Microseismic data recorded by surface arrays are often strongly contaminated by unwanted noise. This background noise makes the detection of small magnitude events difficult. A noise level estimation and noise reduction algorithm is presented for microseismic data analysis based upon minimally controlled recursive averaging and neighborhood shrinkage estimators. The method might not be compared with more sophisticated and computationally expensive denoising algorithm in terms of preserving detailed features of seismic signal. However, it is fast and data-driven and can be applied in real-time processing of continuous data for event detection purposes. Results from application of this algorithm to synthetic and real seismic data show that it holds a great promise for improving microseismic event detection.

  3. Stable isotopes of oxygen and carbon compositions in the Neoproterozoic of South Gabon (Schisto-Calcaire Subgroup, Nyanga Basin): Are cap carbonates and lithoherms recording a particular destabilization event after the Marinoan glaciation?

    NASA Astrophysics Data System (ADS)

    Préat, Alain; Prian, Jean-Pierre; Thiéblemont, Denis; Obame, Rolf Mabicka; Delpomdor, Franck

    2011-06-01

    Geologic evidence of tropical sea level glaciation in the Neoproterozoic remains a matter of debate in the Snowball Earth hypothesis. The Niari Tillite Formation and the cap carbonates record the late Neoproterozoic Marinoan glaciation in South Gabon. These cap carbonates are located at the base of the Schisto-Calcaire Subgroup a predominantly carbonate succession that rests with sharp contact on top of the Niari Tillite. Integrating sedimentological and stable isotope data, a consistent sequence of precipitation events is proposed, with strongly negative δ 13C values pointing to a particular event in the cap carbonates (average δ 13C value = -3.2‰ V-PDB) and in a further newly defined lithohermal unit (average δ 13C value = -4.6‰ V-PDB). Subsequent shallow evaporitive platform carbonates display carbon and oxygen isotopic compositions indicative of relatively unaltered seawater values. Strongly negative δ 18O values in the lithoherms and replacement of aragonite fans by equigranular calcite suggest flushing of meteoric water derived from glacial meltwater.

  4. Separate activation of fast and slow inhibitory postsynaptic potentials in rat neocortex in vitro.

    PubMed Central

    Benardo, L S

    1994-01-01

    Synaptic inhibition was investigated by stimulating inhibitory neurones with focal microapplications of glutamate, while recording from layer V pyramidal neurones of rat somatosensory cortical slices. One class of inhibitory postsynaptic potentials (IPSPs) thus elicited was characterized as a fast, chloride-mediated, GABAA IPSP in part by its fast time-to-peak (mean 2.5 ms) and brief duration, but primarily on the basis of its reversal potential at -68 mV, and its blockade by picrotoxin. The average peak amplitude for these fast IPSPs was -1.5 mV, measured at -60 mV. The peak conductance calculated for these events was about 10 nS. The conductance change associated with the maximal fast inhibitory postsynaptic potential resulting from electrical stimulation of afferent pathways ranged up to 116 nS. A second class of IPSP was encountered much less frequently. These glutamate-triggered events were characterized as slow, potassium-mediated GABAB IPSPs partly because of their longer times-to-peak (mean, 45 ms) and duration, but especially because of their extrapolated equilibrium potential at about -89 mV and blockade by 2-hydroxysaclofen. The average peak amplitude for these slow IPSPs was -2.3 mV, measured at -60 mV. The peak conductance for these events was about 8 nS. IPSPs resulting from the excitation of individual inhibitory interneurones were elicited by glutamate microapplication at particular locations relative to recording sites. Both fast and slow IPSPs were generated, but these occurred as separate events, and mixed responses were never seen. Thus, the two mechanistically distinct types of IPSPs which result from GABA interaction at GABAA and GABAB receptors on neocortical neurones may be mediated by separate classes of inhibitory neurones. PMID:7913968

  5. U-Pb isotopic results for single shocked and polycrystalline zircons record 550-65.5-Ma ages for a K-T target site and 2700-1850-Ma ages for the Sudbury impact event

    NASA Technical Reports Server (NTRS)

    Krogh, T. E.; Kamo, S. L.; Bohor, B. F.

    1992-01-01

    The refractory mineral zircon develops distinct morphological features during shock metamorphism and retains these features under conditions that would anneal them in other minerals. In addition, weakly shocked zircon grains give primary ages for the impact site, while highly reconstituted (polycrystalline) single grains give ages that approach the age of the impact event. Data for a series of originally coeval grains will define a mixing line that gives both of these ages providing that no subsequent geological disturbances have overprinted the isotopic systematics. In this study, we have shown that the three zircon grain types described by Bohor, from both K-T distal ejecta (Fireball layer, Raton Basin, Colorado) and the Onaping Formation, represent a progressive increase in impact-related morphological change that coincides with a progressive increase in isotopic resetting in zircons from the ejecta and basement rocks. Unshocked grains are least affected by isotopic resetting while polycrystalline grains are most affected. U-Pb isotopic results for 12 of 14 single zircon grains from the Fireball layer plot on or close to a line recording a primary age of 550 +/- 10 Ma and a secondary age of 65.5 +/- 3 Ma. Data for the least and most shocked grains plot closest to the primary and secondary ages respectively. The two other grains each give ages between 300 and 350 Ma. This implies that the target ejecta was dominated by 550-Ma rocks and that the recrystallization features of the zircon were superimposed during the impact event at 65.5 Ma. A predominant age of 550 Ma for zircons from the Fireball layer provides an excellent opportunity to identify the impact site and to test the hypothesis that multiple impacts occurred at this time. A volcanic origin for the Fireball layer is ruled out by shock-related morphological changes in zircon and the fact that the least shocked grains are old. Basement Levack gneisses north of the Sudbury structure have a primary age of

  6. Contrasting Large Solar Events

    NASA Astrophysics Data System (ADS)

    Lanzerotti, Louis J.

    2010-10-01

    After an unusually long solar minimum, solar cycle 24 is slowly beginning. A large coronal mass ejection (CME) from sunspot 1092 occurred on 1 August 2010, with effects reaching Earth on 3 August and 4 August, nearly 38 years to the day after the huge solar event of 4 August 1972. The prior event, which those of us engaged in space research at the time remember well, recorded some of the highest intensities of solar particles and rapid changes of the geomagnetic field measured to date. What can we learn from the comparisons of these two events, other than their essentially coincident dates? One lesson I took away from reading press coverage and Web reports of the August 2010 event is that the scientific community and the press are much more aware than they were nearly 4 decades ago that solar events can wreak havoc on space-based technologies.

  7. 76 FR 47478 - Event Data Recorders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-05

    ... Federal Register issued a correction notice for the data in Table II of the final rule. See 73 FR 8408... future use. \\2\\ See 71 FR 50998. Specifically, the regulation, 49 CFR part 563 (Part 563), applies to... that meets the specified performance requirements. In January 2008 (73 FR 2168), the agency amended...

  8. 77 FR 47552 - Event Data Recorders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-09

    ... with any available EDR technology that meets the specified performance requirements. \\1\\ 71 FR 50998... August 2006 final rule, and made the following amendments to Part 563: \\3\\ 73 FR 2168. Clarified the... Register notice on February 8, 2008 (73 FR 8408) to correct the placement of decimal points for data...

  9. Optical imaging of fast, dynamic neurophysiological function.

    SciTech Connect

    Rector, D. M.; Carter, K. M.; Yao, X.; George, J. S.

    2002-01-01

    Fast evoked responses were imaged from rat dorsal medulla and whisker barrel cortex. To investigate the biophysical mechanisms involved, fast optical responses associated with isolated crustacean nerve stimulation were recorded using birefringence and scattered light. Such studies allow optimization of non-invasive imaging techniques being developed for use in humans.

  10. Neocortical very fast oscillations (ripples, 80-200 Hz) during seizures: intracellular correlates.

    PubMed

    Grenier, François; Timofeev, Igor; Steriade, Mircea

    2003-02-01

    Multi-site field potential and intracellular recordings from various neocortical areas were used to study very fast oscillations or ripples (80-200 Hz) during electrographic seizures in cats under ketamine-xylazine anesthesia. The animals displayed spontaneously occurring and electrically induced seizures comprising spike-wave complexes (2-3 Hz) and fast runs (10-20 Hz). Neocortical ripples had much higher amplitudes during seizures than during the slow oscillation preceding the onset of seizures. A series of experimental data from the present study supports the hypothesis that ripples are implicated in seizure initiation. Ripples were particularly strong at the onset of seizures and halothane, which antagonizes the occurrence of ripples, also blocked seizures. The firing of electrophysiologically defined cellular types was phase-locked with ripples in simultaneously recorded field potentials. This indicates that ripples during paroxysmal events are associated with a coordination of firing in a majority of neocortical neurons. This was confirmed with dual intracellular recordings. Based on the amplitude that neocortical ripples reach during paroxysmal events, we propose a mechanism by which neocortical ripples during normal network activity could actively participate in the initiation of seizures on reaching a certain threshold amplitude. This mechanism involves a vicious feedback loop in which very fast oscillations in field potentials are a reflection of synchronous action potentials, and in turn these oscillations help generate and synchronize action potentials in adjacent neurons through electrical interactions.

  11. A multi-proxy approach to tracing a regressive event at Ferguson's Gulf, Lake Turkana, Kenya: Implications for modern analogues to assist in interpretations of the Plio-Pleistocene record

    NASA Astrophysics Data System (ADS)

    Beck, Catherine; Feibel, Craig; Wright, James; Mortlock, Richard

    2014-05-01

    Located in the East African Rift Valley, the Turkana Basin has long been central to our understanding of how early hominins evolved. In particular, there is great curiosity as to the relationship between the paleoenvironment/paleoclimate conditions and evolution. Historical records aid in the interpretation of Plio-Pleistocene sediments by creating the opportunity to ground truth assumptions through the use of modern analogues. This project uses high-resolution, multi-proxy records from a series of short cores spanning the Little Ice Age to the modern, to suggest one possible model for how regressive events are recorded in lacustrine sequences. Because Lake Turkana is hydrologically closed, changes in lake level affect the water chemistry and thereby the ecosystems that depend upon it. Ferguson's Gulf is a 13 km2, shallow embayment located on the western shore of Lake Turkana. The gulf is connected to the rest of the lake by a narrow mouth on its northern end which is ~1 m deep. Therefore, relatively minor drops in lake level have the potential to restrict flow from Lake Turkana into Ferguson's Gulf, creating localized evaporative water chemistry which effects the suitability of this area for sustaining various benthic populations. Six short cores collected in 2011 and 2012 were picked for ostracods at 1-5 cm intervals to study the changes in assemblages and total abundances through time. An age model, generated using radiocarbon dating of ostracods, demonstrated that the record extending into the Little Ice Age (1550-1850 AD), a period when wetter conditions prevailed within the Turkana Basin. The ostracod faunal results were compared with sedimentology/stratigraphy, XRF data, and stable isotope analysis on ostracod shells for a multiproxy approach to reconstructing hydrologic conditions during the past ~500 years. The Ferguson's Gulf record can be subdivided into three bins based on the ostracod assemblages. The lowest third of the core shows high ostracod total

  12. Event selection services in ATLAS

    NASA Astrophysics Data System (ADS)

    Cranshaw, J.; Cuhadar-Donszelmann, T.; Gallas, E.; Hrivnac, J.; Kenyon, M.; McGlone, H.; Malon, D.; Mambelli, M.; Nowak, M.; Viegas, F.; Vinek, E.; Zhang, Q.

    2010-04-01

    ATLAS has developed and deployed event-level selection services based upon event metadata records ("TAGS") and supporting file and database technology. These services allow physicists to extract events that satisfy their selection predicates from any stage of data processing and use them as input to later analyses. One component of these services is a web-based Event-Level Selection Service Interface (ELSSI). ELSSI supports event selection by integrating run-level metadata, luminosity-block-level metadata (e.g., detector status and quality information), and event-by-event information (e.g., triggers passed and physics content). The list of events that survive after some selection criterion is returned in a form that can be used directly as input to local or distributed analysis; indeed, it is possible to submit a skimming job directly from the ELSSI interface using grid proxy credential delegation. ELSSI allows physicists to explore ATLAS event metadata as a means to understand, qualitatively and quantitatively, the distributional characteristics of ATLAS data. In fact, the ELSSI service provides an easy interface to see the highest missing ET events or the events with the most leptons, to count how many events passed a given set of triggers, or to find events that failed a given trigger but nonetheless look relevant to an analysis based upon the results of offline reconstruction, and more. This work provides an overview of ATLAS event-level selection services, with an emphasis upon the interactive Event-Level Selection Service Interface.

  13. Capabilities of a Global 3D MHD Model for Monitoring Extremely Fast CMEs

    NASA Astrophysics Data System (ADS)

    Wu, C. C.; Plunkett, S. P.; Liou, K.; Socker, D. G.; Wu, S. T.; Wang, Y. M.

    2015-12-01

    Since the start of the space era, spacecraft have recorded many extremely fast coronal mass ejections (CMEs) which have resulted in severe geomagnetic storms. Accurate and timely forecasting of the space weather effects of these events is important for protecting expensive space assets and astronauts and avoiding communications interruptions. Here, we will introduce a newly developed global, three-dimensional (3D) magnetohydrodynamic (MHD) model (G3DMHD). The model takes the solar magnetic field maps at 2.5 solar radii (Rs) and intepolates the solar wind plasma and field out to 18 Rs using the algorithm of Wang and Sheeley (1990, JGR). The output is used as the inner boundary condition for a 3D MHD model. The G3DMHD model is capable of simulating (i) extremely fast CME events with propagation speeds faster than 2500 km/s; and (ii) multiple CME events in sequence or simultaneously. We will demonstrate the simulation results (and comparison with in-situ observation) for the fastest CME in record on 23 July 2012, the shortest transit time in March 1976, and the well-known historic Carrington 1859 event.

  14. CD Recorders.

    ERIC Educational Resources Information Center

    Falk, Howard

    1998-01-01

    Discussion of CD (compact disc) recorders describes recording applications, including storing large graphic files, creating audio CDs, and storing material downloaded from the Internet; backing up files; lifespan; CD recording formats; continuous recording; recording software; recorder media; vulnerability of CDs; basic computer requirements; and…

  15. Circum-Antarctic warming events between 4 and 3.5 Ma recorded in marine sediments from the Prydz Bay (ODP Leg 188) and the Antarctic Peninsula (ODP Leg 178) margins

    NASA Astrophysics Data System (ADS)

    Escutia, C.; Bárcena, M. A.; Lucchi, R. G.; Romero, O.; Ballegeer, A. M.; Gonzalez, J. J.; Harwood, D. M.

    2009-11-01

    , and 2) decrease in SSSTs (from > 5.6 °C at 3.7 Ma to 4°-2.7 °C at 3.6 Ma, and 2.5 °C at 3.5 Ma.) indicated by the silicoflagellate W/C R from Site 1165. We postulate that, although the start of a cooling trend is recorded at about 3.7-3.6-Ma, relatively warm conditions prevailed until 3.5 Ma capable of maintained open marine conditions with reduced or no sea-ice and reduced ice sheet volume and extent. The information in this paper regarding the timing of continental-wide and regional warm events and the paleoenvironmental conditions that characterized them (i.e., SSST, extent of sea ice, and ice sheet size) are relevant to help constrain paleoclimate and ice sheet models for the early-middle Pliocene, a time period when the level of warming according to the Intergovernmental Panel on Climate Change 2007 report, is within range of the estimates of the Earth's global temperature increases for the 21st century. These data, when linked to modeling studies like those of Pollard and DeConto (2009) will further our understanding of how these ice sheets may respond to future warming of the southern high latitudes.

  16. Video Event Trigger

    NASA Technical Reports Server (NTRS)

    Williams, Glenn L.; Lichter, Michael J.

    1994-01-01

    Video event trigger (VET) processes video image data to generate trigger signal when image shows significant change like motion or appearance, disappearance, change in color, change in brightness, or dilation of object. System aids in efficient utilization of image-data-storage and image-data-processing equipment in applications in which many video frames show no changes and are wasteful to record and analyze all frames when only relatively few frames show changes of interest. Applications include video recording of automobile crash tests, automated video monitoring of entrances, exits, parking lots, and secure areas.

  17. A sea-floor spreading event captured by seismometers.

    PubMed

    Tolstoy, M; Cowen, J P; Baker, E T; Fornari, D J; Rubin, K H; Shank, T M; Waldhauser, F; Bohnenstiehl, D R; Forsyth, D W; Holmes, R C; Love, B; Perfit, M R; Weekly, R T; Soule, S A; Glazer, B

    2006-12-22

    Two-thirds of Earth's surface is formed at mid-ocean ridges, yet sea-floor spreading events are poorly understood because they occur far beneath the ocean surface. At 9 degrees 50'N on the East Pacific Rise, ocean-bottom seismometers recently recorded the microearthquake character of a mid-ocean ridge eruption, including precursory activity. A gradual ramp-up in activity rates since seismic monitoring began at this site in October 2003 suggests that eruptions may be forecast in the fast-spreading environment. The pattern culminates in an intense but brief (approximately 6-hour) inferred diking event on 22 January 2006, followed by rapid tapering to markedly decreased levels of seismicity.

  18. Fast SCR Thyratron Driver

    SciTech Connect

    Nguyen, M.N.; /SLAC

    2007-06-18

    As part of an improvement project on the linear accelerator at SLAC, it was necessary to replace the original thyratron trigger generator, which consisted of two chassis, two vacuum tubes, and a small thyratron. All solid-state, fast rise, and high voltage thyratron drivers, therefore, have been developed and built for the 244 klystron modulators. The rack mounted, single chassis driver employs a unique way to control and generate pulses through the use of an asymmetric SCR, a PFN, a fast pulse transformer, and a saturable reactor. The resulting output pulse is 2 kV peak into 50 {Omega} load with pulse duration of 1.5 {mu}s FWHM at 180 Hz. The pulse risetime is less than 40 ns with less than 1 ns jitter. Various techniques are used to protect the SCR from being damaged by high voltage and current transients due to thyratron breakdowns. The end-of-line clipper (EOLC) detection circuit is also integrated into this chassis to interrupt the modulator triggering in the event a high percentage of line reflections occurred.

  19. [Adverse events prevention ability].

    PubMed

    Aparo, Ugo Luigi; Aparo, Andrea

    2007-03-01

    The issue of how to address medical errors is the key to improve the health care system performances. Operational evidence collected in the last five years shows that the solution is only partially linked to future technological developments. Cultural and organisational changes are mandatory to help to manage and drastically reduce the adverse events in health care organisations. Classical management, merely based on coordination and control, is inadequate. Proactive, self-organising network based structures must be put in place and managed using adaptive, fast evolving management tools. PMID:17484160

  20. [Adverse events prevention ability].

    PubMed

    Aparo, Ugo Luigi; Aparo, Andrea

    2007-03-01

    The issue of how to address medical errors is the key to improve the health care system performances. Operational evidence collected in the last five years shows that the solution is only partially linked to future technological developments. Cultural and organisational changes are mandatory to help to manage and drastically reduce the adverse events in health care organisations. Classical management, merely based on coordination and control, is inadequate. Proactive, self-organising network based structures must be put in place and managed using adaptive, fast evolving management tools.

  1. The siting record: An account of the programs of federal agencies and events that have led to the selection of a potential site for a geologic respository for high-level radioactive waste

    SciTech Connect

    Lomenick, T.F.

    1996-03-01

    This record of siting a geologic repository for high-level radioactive wastes (HLW) and spent fuel describes the many investigations that culminated on December 22, 1987 in the designation of Yucca Mountain (YM), as the site to undergo detailed geologic characterization. It recounts the important issues and events that have been instrumental in shaping the course of siting over the last three and one half decades. In this long task, which was initiated in 1954, more than 60 regions, areas, or sites involving nine different rock types have been investigated. This effort became sharply focused in 1983 with the identification of nine potentially suitable sites for the first repository. From these nine sites, five were subsequently nominated by the U.S. Department of Energy (DOE) as suitable for characterization and then, in 1986, as required by the Nuclear Waste Policy Act of 1982 (NWPA), three of these five were recommended to the President as candidates for site characterization. President Reagan approved the recommendation on May 28, 1986. DOE was preparing site characterization plans for the three candidate sites, namely Deaf Smith County, Texas; Hanford Site, Washington; and YM. As a consequence of the 1987 Amendment to the NWPA, only the latter was authorized to undergo detailed characterization. A final Site Characterization Plan for Yucca Mountain was published in 1988. Prior to 1954, there was no program for the siting of disposal facilities for high-level waste (HLW). In the 1940s and 1950s, the volume of waste, which was small and which resulted entirely from military weapons and research programs, was stored as a liquid in large steel tanks buried at geographically remote government installations principally in Washington and Tennessee.

  2. Comparative Analyses of Two Extremely Fast CMEs Induced Shocks using A H3DMHD Model

    NASA Astrophysics Data System (ADS)

    Wu, S. T.; Wu, C. C.; Liou, K.; Dryer, Ph D., M.; Plunkett, S. P.

    2015-12-01

    During the last two decades, spacecraft recorded several extremely fast Coronal Mass Ejections (CMEs) which have resulted in severe geomagnetic storms. Here, we will report results from a comparative study of two extremely fast CME events: one on 29 October 2003 (Halloween 2003 epoch) and the other on 23 July 2012. Both shock events reached 1 AU within ~20 hours. We employed a global three-dimensional (3D) magnetohydrodynamics (MHD) simulation model (H3DMHD, Wu et al. 2007, JGR) to study these two events and compared the results with observations (e.g., 1 AU in-situ data, and coronal images from SOHO/LASCO or STEREO/ SECCHI). It was found that: (i) The peak temperature, velocity, and density of the solar wind for the shock/ICME event are 2 x 107 K, 2500 km s-1, and 35 cm-3, respectively. (ii) The peaks of magnetic field (B) are ~60 and 110 nT for the event on 29 October 2003 and 23 July 2012, respectively. Solar wind densities behind the shocks are extremely low which are due to rarefaction of the interplanetary shocks' propagation. We will discuss this issue in the presentation. Simulations are vastly improved and forecasting arrival times should be done as noted in real time by Zhou and Dryer (Space Weather Quarterly, 2014) review, but CME and B therein is still a major challenge for storm prediction.

  3. Development of ultra-fast 2D ion Doppler tomography using image intensified CMOS fast camera

    NASA Astrophysics Data System (ADS)

    Tanabe, Hiroshi; Kuwahata, Akihiro; Yamanaka, Haruki; Inomoto, Michiaki; Ono, Yasushi; TS-group Team

    2015-11-01

    The world fastest novel time-resolved 2D ion Doppler tomography diagnostics has been developed using fast camera with high-speed gated image intensifier (frame rate: 200kfps. phosphor decay time: ~ 1 μ s). Time evolution of line-integrated spectra are diffracted from a f=1m, F/8.3 and g=2400L/mm Czerny-Turner polychromator, whose output is intensified and recorded to a high-speed camera with spectral resolution of ~0.005nm/pixel. The system can accommodate up to 36 (9 ×4) spatial points recorded at 5 μs time resolution, tomographic reconstruction is applied for the line-integrated spectra, time-resolved (5 μs/frame) local 2D ion temperature measurement has been achieved without any assumption of shot repeatability. Ion heating during intermittent reconnection event which tends to happen during high guide field merging tokamak was measured around diffusion region in UTST. The measured 2D profile shows ion heating inside the acceleration channel of reconnection outflow jet, stagnation point and downstream region where reconnected field forms thick closed flux surface as in MAST. Achieved maximum ion temperature increases as a function of Brec2 and shows good fit with MAST experiment, demonstrating promising CS-less startup scenario for spherical tokamak. This work is supported by JSPS KAKENHI Grant Number 15H05750 and 15K20921.

  4. Transformational Events

    ERIC Educational Resources Information Center

    Denning, Peter J.; Hiles, John E.

    2006-01-01

    Transformational Events is a new pedagogic pattern that explains how innovations (and other transformations) happened. The pattern is three temporal stages: an interval of increasingly unsatisfactory ad hoc solutions to a persistent problem (the "mess"), an offer of an invention or of a new way of thinking, and a period of widespread adoption and…

  5. Maintenance Event

    Atmospheric Science Data Center

    2014-07-22

    Time:  08:00 am - 08:30 am EDT Event Impact:  Science Directorate websites will ... outage Thursday morning, 7/24, to perform upgrades to the web environment and are expected to be down for about 30 minutes. ...

  6. The Effect of Different Fast-ion Instabilities on the Fast-ion Profile

    NASA Astrophysics Data System (ADS)

    Ruskov, E.; Heidbrink, W.; Liu, D.; Fredrickson, E.; Bortolon, A.

    2014-10-01

    Fast-ion driven instabilities in NSTX take many forms, including steady, bursting, and avalanching toroidal Alfven eigenmodes (TAE), avalanching global AEs, energetic particle modes (EPM), long-lived modes (LLM) and abrupt large-amplitude events (ALE). The occurrence or absence of these modes on Mirnov signals correlates with the ratio of fast-ion to Alfven speed and the ratio of fast-ion to thermal pressure. The drop in neutron rate at these events correlates differently with mode amplitude for the different types of events. In this study, we expand this database to investigate the correlation of vertical fast-ion D-alpha (FIDA) data with the different types of MHD. The measured profiles are compared with classically-predicted profiles. Work supported by US DOE Grant DE-FG02-06ER54867.

  7. Short-term fasts increase levels of halogenated flame retardants in tissues of a wild incubating bird.

    PubMed

    Marteinson, Sarah C; Drouillard, Ken G; Verreault, Jonathan

    2016-04-01

    Many species are adapted for fasting during parts of their life cycle. For species undergoing extreme fasts, lipid stores are mobilized and accumulated contaminants can be released to exert toxicological effects. However, it is unknown if short-term fasting events may have a similar effect. The objective of this study was to determine if short successive fasts are related to contaminant levels in liver and plasma of birds. In ring-billed gulls (Larus delawarensis), both members of the pair alternate between incubating the nest for several hours (during which they fast) and foraging, making them a useful model for examining this question. Birds were equipped with miniature data loggers recording time and GPS position for two days to determine the proportion and duration of time birds spent in these two activities. Liver and plasma samples were collected, and halogenated flame retardants (HFRs) (PBDEs and dechlorane plus) and organochlorines (OCs) (PCBs, DDTs, and chlordane-related compounds) were determined. Most birds (79%) exhibited plasma lipid content below 1%, indicating a likely fasted state, and plasma lipid percent declined with the number of hours spent at the nest site. The more time birds spent at their nest site, the higher were their plasma and liver concentrations of HFRs. However, body condition indices were unrelated to either the amount of time birds fasted at the nest site or contaminant levels, suggesting that lipid mobilization might not have been severe enough to affect overall body condition of birds and to explain the relationship between fasting and HFR concentrations. A similar relationship between fasting and OC levels was not observed, suggesting that different factors are affecting short-term temporal variations in concentrations of these two classes of contaminants. This study demonstrates that short fasts can be related to increased internal contaminant exposure in birds and that this may be a confounding factor in research and

  8. Short-term fasts increase levels of halogenated flame retardants in tissues of a wild incubating bird.

    PubMed

    Marteinson, Sarah C; Drouillard, Ken G; Verreault, Jonathan

    2016-04-01

    Many species are adapted for fasting during parts of their life cycle. For species undergoing extreme fasts, lipid stores are mobilized and accumulated contaminants can be released to exert toxicological effects. However, it is unknown if short-term fasting events may have a similar effect. The objective of this study was to determine if short successive fasts are related to contaminant levels in liver and plasma of birds. In ring-billed gulls (Larus delawarensis), both members of the pair alternate between incubating the nest for several hours (during which they fast) and foraging, making them a useful model for examining this question. Birds were equipped with miniature data loggers recording time and GPS position for two days to determine the proportion and duration of time birds spent in these two activities. Liver and plasma samples were collected, and halogenated flame retardants (HFRs) (PBDEs and dechlorane plus) and organochlorines (OCs) (PCBs, DDTs, and chlordane-related compounds) were determined. Most birds (79%) exhibited plasma lipid content below 1%, indicating a likely fasted state, and plasma lipid percent declined with the number of hours spent at the nest site. The more time birds spent at their nest site, the higher were their plasma and liver concentrations of HFRs. However, body condition indices were unrelated to either the amount of time birds fasted at the nest site or contaminant levels, suggesting that lipid mobilization might not have been severe enough to affect overall body condition of birds and to explain the relationship between fasting and HFR concentrations. A similar relationship between fasting and OC levels was not observed, suggesting that different factors are affecting short-term temporal variations in concentrations of these two classes of contaminants. This study demonstrates that short fasts can be related to increased internal contaminant exposure in birds and that this may be a confounding factor in research and

  9. A space-based radio frequency transient event classifier

    SciTech Connect

    Moore, K.R.; Blain, C.P.; Caffrey, M.P.; Franz, R.C.; Henneke, K.M.; Jones, R.G.

    1998-03-01

    The Department of Energy is currently investigating economical and reliable techniques for space-based nuclear weapon treaty verification. Nuclear weapon detonations produce RF transients that are signatures of illegal nuclear weapons tests. However, there are many other sources of RF signals, both natural and man-made. Direct digitization of RF signals requires rates of 300 MSamples per second and produces 10{sup 13} samples per day of data to analyze. it is impractical to store and downlink all digitized RF data from such a satellite without a prohibitively expensive increase in the number and capacities of ground stations. Reliable and robust data processing and information extraction must be performed onboard the spacecraft in order to reduce downlinked data to a reasonable volume. The FORTE (Fast On-Orbit Recording of Transient Events) satellite records RF transients in space. These transients will be classified onboard the spacecraft with an Event Classifier specialized hardware that performs signal preprocessing and neural network classification. The authors describe the Event Classifier requirements, scientific constraints, design and implementation.

  10. Rounding effects in record statistics.

    PubMed

    Wergen, G; Volovik, D; Redner, S; Krug, J

    2012-10-19

    We analyze record-breaking events in time series of continuous random variables that are subsequently discretized by rounding to integer multiples of a discretization scale Δ>0. Rounding leads to ties of an existing record, thereby reducing the number of new records. For an infinite number of random variables that are drawn from distributions with a finite upper limit, the number of discrete records is finite, while for distributions with a thinner than exponential upper tail, fewer discrete records arise compared to continuous variables. In the latter case, the record sequence becomes highly regular at long times.

  11. Observation and interpretation of fast sub-visual light pulses from the night sky

    NASA Technical Reports Server (NTRS)

    Nemzek, R. J.; Winckler, J. R.

    1989-01-01

    Fast large-aperture photometers directed at the zenith on clear nights near Minneapolis have recorded many light pulses in the msec time range, but aside from man-made events these were almost entirely due to Rayleigh-scattered distant lightning, with a residual very low rate (less than 0.1/hr) of unidentified pulses. It is argued that 1-msec light pulses seen in several previous experiments may also be mostly Rayleigh-scattered lightning, rather than fluorescent light due to electron precipitation from lightning-induced whistlers as previously proposed.

  12. Fast frame scanning camera system for light-sheet microscopy.

    PubMed

    Wu, Di; Zhou, Xing; Yao, Baoli; Li, Runze; Yang, Yanlong; Peng, Tong; Lei, Ming; Dan, Dan; Ye, Tong

    2015-10-10

    In the interest of improving the temporal resolution for light-sheet microscopy, we designed a fast frame scanning camera system that incorporated a galvanometer scanning mirror into the imaging path of a home-built light-sheet microscope. This system transformed a temporal image sequence to a spatial one so that multiple images could be acquired during one exposure period. The improvement factor of the frame rate was dependent on the number of sub-images that could be tiled on the sensor without overlapping each other and was therefore a trade-off with the image size. As a demonstration, we achieved 960 frames/s (fps) on a CCD camera that was originally capable of recording images at only 30 fps (full frame). This allowed us to observe millisecond or sub-millisecond events with ordinary CCD cameras.

  13. Fast frame scanning camera system for light-sheet microscopy.

    PubMed

    Wu, Di; Zhou, Xing; Yao, Baoli; Li, Runze; Yang, Yanlong; Peng, Tong; Lei, Ming; Dan, Dan; Ye, Tong

    2015-10-10

    In the interest of improving the temporal resolution for light-sheet microscopy, we designed a fast frame scanning camera system that incorporated a galvanometer scanning mirror into the imaging path of a home-built light-sheet microscope. This system transformed a temporal image sequence to a spatial one so that multiple images could be acquired during one exposure period. The improvement factor of the frame rate was dependent on the number of sub-images that could be tiled on the sensor without overlapping each other and was therefore a trade-off with the image size. As a demonstration, we achieved 960 frames/s (fps) on a CCD camera that was originally capable of recording images at only 30 fps (full frame). This allowed us to observe millisecond or sub-millisecond events with ordinary CCD cameras. PMID:26479797

  14. Magnetic Recording.

    ERIC Educational Resources Information Center

    Lowman, Charles E.

    A guide to the technology of magnetic recorders used in such fields as audio recording, broadcast and closed-circuit television, instrumentation recording, and computer data systems is presented. Included are discussions of applications, advantages, and limitations of magnetic recording, its basic principles and theory of operation, and its…

  15. A repeating fast radio burst.

    PubMed

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star. PMID:26934226

  16. A repeating fast radio burst.

    PubMed

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  17. Fast rise times and the physical mechanism of deep earthquakes

    NASA Technical Reports Server (NTRS)

    Houston, H.; Williams, Q.

    1991-01-01

    A systematic global survey of the rise times and stress drops of deep and intermediate earthquakes is reported. When the rise times are scaled to the seismic moment release of the events, their average is nearly twice as fast for events deeper than about 450 km as for shallower events.

  18. The role of vitamin B12 in fasting hyperhomocysteinemia and its interaction with the homozygous C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene. A case-control study of patients with early-onset thrombotic events.

    PubMed

    D'Angelo, A; Coppola, A; Madonna, P; Fermo, I; Pagano, A; Mazzola, G; Galli, L; Cerbone, A M

    2000-04-01

    Total fasting plasma homocysteine (tHcy), homozygosity for the C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene and for the A2756G mutation of the methionine synthase (MS) gene, vitamin B12 and folate plasma levels were evaluated in 170 consecutive patients (89 M, 81 F; mean age 41 +/- 12 yrs) with documented early-onset thrombosis (89 venous, 69 arterial, 12 both; mean age at first episode 36 +/- 11 yrs), and in 182 age- and sex-matched healthy control subjects. Moderate hyperhomocysteinemia (HHcy, tHcy >19.5 microM in men and >15 microM in women) was detected in 45 patients (26.5%) and in 18 controls (9.9%, Mantel-Haenszel OR and 95% C.I. after stratification for arterial or venous thrombosis: 3.25, 1.78-5.91). The 677TT MTHFR genotype was not significantly more prevalent in patients (27.6%) than in controls (21.4%, RR = 1.42: 0.84-2.41), and markedly contributed to HHcy (Mantel-Haenszel RR after stratification for case/control status: 8.29, 4.61-14.9). The 2756GG MS genotype, observed in 4 patients (2.4%) and 8 controls (4.4%), was not associated to HHcy. tHcy was negatively correlated to folate and vitamin B12 levels, with better correlation found in subjects with the 677TT mutation (r = -0.42 and -0.25) than with the 677CC or CT MTHFR genotype (r = 0).37 and -0.11). However, folate was similar in patients and controls and vitamin B12 was higher in patients (460 +/- 206 vs. 408 +/-185 pg/ml, p = 0.011). In a generalized linear model, 44% of the variation in tHcy levels was explained by folate and vitamin B12 levels, the MTHFR genotype, gender, and by the interaction of the MTHFR genotype with folate (p < or =0.028); the interactions of vitamin B12 with the MTHFR genotype, gender and patient/control status also significantly contributed to the variation in tHcy levels (p < or =0.028). A 4-week administration of 5-methyltetrahydrofolate (15 mg/day) markedly lowered plasma tHcy in 24 patients with MTHFR 677TT genotype, but the response to

  19. Innovative use of DSP technology in space: FORTE event classifier

    SciTech Connect

    Briles, S.; Moore, K. Jones, R.; Klingner, P.; Neagley, D.; Caffrey, M.; Henneke, K.; Spurgen, W.; Blain, P.

    1994-08-01

    The Fast On-Orbit Recording of Transient Events (FORTE) small satellite will field a digital signal processor (DSP) experiment for the purpose of classifying radio-frequency (rf) transient signals propagating through the earth`s ionosphere. Designated the Event Classifier experiment, this DSP experiment uses a single Texas Instruments` SMJ320C30 DSP to execute preprocessing, feature extraction, and classification algorithms on down-converted, digitized, and buffered rf transient signals in the frequency range of 30 to 300 MHz. A radiation-hardened microcontroller monitors DSP- abnormalities and supervises spacecraft command communications. On- orbit evaluation of multiple algorithms is supported by the Event Classifier architecture. Ground-based commands determine the subset and sequence of algorithms executed to classify a captured time series. Conventional neural network classification algorithms will be some of the classification techniques implemented on-board FORTE while in a low-earth orbit. Results of all experiments, after being stored in DSP flash memory, will be transmitted through the spacecraft to ground stations. The Event Classifier is a versatile and fault-tolerant experiment that is an important new space-based application of DSP technology.

  20. Single event mass spectrometry

    DOEpatents

    Conzemius, Robert J.

    1990-01-16

    A means and method for single event time of flight mass spectrometry for analysis of specimen materials. The method of the invention includes pulsing an ion source imposing at least one pulsed ion onto the specimen to produce a corresponding emission of at least one electrically charged particle. The emitted particle is then dissociated into a charged ion component and an uncharged neutral component. The ion and neutral components are then detected. The time of flight of the components are recorded and can be used to analyze the predecessor of the components, and therefore the specimen material. When more than one ion particle is emitted from the specimen per single ion impact, the single event time of flight mass spectrometer described here furnis This invention was made with Government support under Contract No. W-7405-ENG82 awarded by the Department of Energy. The Government has certain rights in the invention.

  1. Fast food tips (image)

    MedlinePlus

    ... challenge to eat healthy when going to a fast food place. In general, avoiding items that are deep ... challenge to eat healthy when going to a fast food place. In general, avoiding items that are deep ...

  2. Fast food (image)

    MedlinePlus

    Fast foods are quick, reasonably priced, and readily available alternatives to home cooking. While convenient and economical for a busy lifestyle, fast foods are typically high in calories, fat, saturated fat, ...

  3. The ISC Seismic Event Bibliography

    NASA Astrophysics Data System (ADS)

    Di Giacomo, Domenico; Storchak, Dmitry

    2015-04-01

    The International Seismological Centre (ISC) is a not-for-profit organization operating in the UK for the last 50 years and producing the ISC Bulletin - the definitive worldwide summary of seismic events, both natural and anthropogenic - starting from the beginning of 20th century. Often researchers need to gather information related to specific seismic events for various reasons. To facilitate such task, in 2012 we set up a new database linking earthquakes and other seismic events in the ISC Bulletin to bibliographic records of scientific articles (mostly peer-reviewed journals) that describe those events. Such association allows users of the ISC Event Bibliography (www.isc.ac.uk/event_bibliography/index.php) to run searches for publications via a map-based web interface and, optionally, selecting scientific publications related to either specific events or events in the area of interest. Some of the greatest earthquakes were described in several hundreds of articles published over a period of few years. The journals included in our database are not limited to seismology but bring together a variety of fields in geosciences (e.g., engineering seismology, geodesy and remote sensing, tectonophysics, monitoring research, tsunami, geology, geochemistry, hydrogeology, atmospheric sciences, etc.) making this service useful in multidisciplinary studies. Usually papers dealing with large data set are not included (e.g., papers describing a seismic catalogue). Currently the ISC Event Bibliography includes over 17,000 individual publications from about 500 titles related to over 14,000 events that occurred in last 100+ years. The bibliographic records in the Event Bibliography start in the 1950s, and it is updated as new publications become available.

  4. Is fast food addictive?

    PubMed

    Garber, Andrea K; Lustig, Robert H

    2011-09-01

    Studies of food addiction have focused on highly palatable foods. While fast food falls squarely into that category, it has several other attributes that may increase its salience. This review examines whether the nutrients present in fast food, the characteristics of fast food consumers or the presentation and packaging of fast food may encourage substance dependence, as defined by the American Psychiatric Association. The majority of fast food meals are accompanied by a soda, which increases the sugar content 10-fold. Sugar addiction, including tolerance and withdrawal, has been demonstrated in rodents but not humans. Caffeine is a "model" substance of dependence; coffee drinks are driving the recent increase in fast food sales. Limited evidence suggests that the high fat and salt content of fast food may increase addictive potential. Fast food restaurants cluster in poorer neighborhoods and obese adults eat more fast food than those who are normal weight. Obesity is characterized by resistance to insulin, leptin and other hormonal signals that would normally control appetite and limit reward. Neuroimaging studies in obese subjects provide evidence of altered reward and tolerance. Once obese, many individuals meet criteria for psychological dependence. Stress and dieting may sensitize an individual to reward. Finally, fast food advertisements, restaurants and menus all provide environmental cues that may trigger addictive overeating. While the concept of fast food addiction remains to be proven, these findings support the role of fast food as a potentially addictive substance that is most likely to create dependence in vulnerable populations.

  5. Is fast food addictive?

    PubMed

    Garber, Andrea K; Lustig, Robert H

    2011-09-01

    Studies of food addiction have focused on highly palatable foods. While fast food falls squarely into that category, it has several other attributes that may increase its salience. This review examines whether the nutrients present in fast food, the characteristics of fast food consumers or the presentation and packaging of fast food may encourage substance dependence, as defined by the American Psychiatric Association. The majority of fast food meals are accompanied by a soda, which increases the sugar content 10-fold. Sugar addiction, including tolerance and withdrawal, has been demonstrated in rodents but not humans. Caffeine is a "model" substance of dependence; coffee drinks are driving the recent increase in fast food sales. Limited evidence suggests that the high fat and salt content of fast food may increase addictive potential. Fast food restaurants cluster in poorer neighborhoods and obese adults eat more fast food than those who are normal weight. Obesity is characterized by resistance to insulin, leptin and other hormonal signals that would normally control appetite and limit reward. Neuroimaging studies in obese subjects provide evidence of altered reward and tolerance. Once obese, many individuals meet criteria for psychological dependence. Stress and dieting may sensitize an individual to reward. Finally, fast food advertisements, restaurants and menus all provide environmental cues that may trigger addictive overeating. While the concept of fast food addiction remains to be proven, these findings support the role of fast food as a potentially addictive substance that is most likely to create dependence in vulnerable populations. PMID:21999689

  6. Periodicity in marine extinction events

    NASA Technical Reports Server (NTRS)

    Sepkoski, J. John, Jr.; Raup, David M.

    1986-01-01

    The periodicity of extinction events is examined in detail. In particular, the temporal distribution of specific, identifiable extinction events is analyzed. The nature and limitations of the data base on the global fossil record is discussed in order to establish limits of resolution in statistical analyses. Peaks in extinction intensity which appear to differ significantly from background levels are considered, and new analyses of the temporal distribution of these peaks are presented. Finally, some possible causes of periodicity and of interdependence among extinction events over the last quarter billion years of earth history are examined.

  7. Dynamic Triggering of Microseismic Events

    NASA Astrophysics Data System (ADS)

    Lu, H.; Van der Baan, M.

    2015-12-01

    Microseismic events are commonly recorded during hydraulic fracturing experiments. In microseismic interpretations, each event is often regarded as independent and uncorrelated to neighboring ones. In reality, both the rock deformation (static stresses) and transient wave motion (dynamic stresses) associated with microseismic events add to the stress field together with the external loading (fluid injection). We believe the resulting static and dynamic stress perturbations will influence both the timing and spatial evolution of the microseismic cloud. We study the dynamic triggering of microseismicity using numerical simulations of a biaxial deformation test by means of a bonded particle method (Potyondy and Cundall, 2004), where crack development can be tracked and analyzed independently. Our methodology is to compare the stress changes due to one specific event with the occurrence of the next few events in the numerical simulations. In addition, we compute the dynamic stress perturbations for recorded large events analytically given their (non-double couple) failure mechanisms. Our results show that cracks following a major event tend to form in zones affected by the dynamic stresses by promoting new failure in areas that are critically stressed. This confirms that dynamic triggering during hydraulic fracturing operations but also larger scale seismicity is likely. It also demonstrates the often complex interplay between the dynamic and static stress changes and their effect on the temporal and spatial evolution of rock deformation at all scales.

  8. Mid-Carboniferous eustatic event

    SciTech Connect

    Saunders, W.B.; Ramsbottom, W.H.C.

    1986-03-01

    Stratigraphic and paleontologic evidence from mid-Carboniferous (Namurian) basin and shelf successions in widely scattered parts of the world indicates that a major eustatic event occurred about 330 Ma. The event began with a regression that is recorded in most shelf sequences, the regression was followed by a brief transgression about 328 Ma, and the event ended with a transgression that flooded large shelf areas about 325 Ma. The Mississippian-Pennsylvanian unconformity in North America is a well-known product of this event, but equally prominent and contemporaneous unconformity surfaces are also present in Europe, North Africa, and elsewhere. The event is believed to have caused numerous extinctions, and it resulted in marked fluctuations in faunal diversity. 94 references, 2 figures.

  9. Fast food: friendly?

    PubMed

    Rice, S; McAllister, E J; Dhurandhar, N V

    2007-06-01

    Fast food is routinely blamed for the obesity epidemic and consequentially excluded from professional dietary recommendations. However, several sections of society including senior citizens, low-income adult and children, minority and homeless children, or those pressed for time appear to rely on fast food as an important source of meals. Considering the dependence of these nutritionally vulnerable population groups on fast food, we examined the possibility of imaginative selection of fast food, which would attenuate the potentially unfavorable nutrient composition. We present a sample menu to demonstrate that it is possible to design a fast food menu that provides reasonable level of essential nutrients without exceeding the caloric recommendations. We would like to alert health-care professionals that fast food need not be forbidden under all circumstances, and that a fresh look at the role of fast food may enable its inclusion in meal planning for those who depend on it out of necessity, while adding flexibility.

  10. Events diary

    NASA Astrophysics Data System (ADS)

    2000-01-01

    as Imperial College, the Royal Albert Hall, the Royal College of Art, the Natural History and Science Museums and the Royal Geographical Society. Under the heading `Shaping the future together' BA2000 will explore science, engineering and technology in their wider cultural context. Further information about this event on 6 - 12 September may be obtained from Sandra Koura, BA2000 Festival Manager, British Association for the Advancement of Science, 23 Savile Row, London W1X 2NB (tel: 0171 973 3075, e-mail: sandra.koura@britassoc.org.uk ). Details of the creating SPARKS events may be obtained from creating.sparks@britassoc.org.uk or from the website www.britassoc.org.uk . Other events 3 - 7 July, Porto Alegre, Brazil VII Interamerican conference on physics education: The preparation of physicists and physics teachers in contemporary society. Info: IACPE7@if.ufrgs.br or cabbat1.cnea.gov.ar/iacpe/iacpei.htm 27 August - 1 September, Barcelona, Spain GIREP conference: Physics teacher education beyond 2000. Info: www.blues.uab.es/phyteb/index.html

  11. Kinetics of fast island decay on Ag(111)

    SciTech Connect

    Morgenstern, Karina; Rosenfeld, Georg; Comsa, George; Sorensen, Mads R.; Hammer, Bjork; Laegsgaard, Erik; Besenbacher, Flemming

    2001-01-15

    The kinetics of fast island decay on Ag(111) close to steps has been studied in scanning tunneling microscopy experiments and atomistic total energy calculations. We show that a breakdown of the step-edge barrier is not sufficient to explain the decay rates observed during fast decay events. From the interplay between experiments and theory, we instead propose that fast decay originates from concerted diffusion processes, which bypass the detachment barrier of atoms from kinks and step sites.

  12. Variability in magnitude of paleoearthquakes revealed by trenching and historical records, along the Haiyuan Fault, China

    NASA Astrophysics Data System (ADS)

    Liu-Zeng, Jing; Shao, Yanxiu; Klinger, Yann; Xie, Kejia; Yuan, Daoyuang; Lei, Zhongsheng

    2015-12-01

    Paleoseismology provides fundamental data for generalizing earthquake recurrence behavior, by revealing past surface-rupturing events. Determining the size of paleoseismic events is notoriously more challenging than their timing. Paleoearthquakes exposed in trenches are vaguely defined as large enough to break to the surface and often assumed to be similar in size. Here we show an example where the paleoseismic record includes events of both moderate and large magnitudes. At the Salt Lake site on the active left-lateral Haiyuan Fault, northern Tibetan Plateau, a high-resolution stratigraphic sequence recorded three and possibly four events since A.D. 1500, constrained by accelerator mass spectrometry 14C dating. Historical accounts of earthquake damage in the study region suggest that several earthquakes exposed in the trenches markedly differ in magnitude. With the exception of the most recent M~8 earthquake that occurred in A.D. 1920, two earlier events, which occurred in A.D. 1760 (or 1709) and 1638, respectively, are considerably smaller, with magnitude M < 7 and more likely M~6 or less. Thus, this section of the Haiyuan Fault that broke during moderate-magnitude events failed again after a short interval during a large Mw 7.8-8.3 earthquake, as part of a larger multisegment rupture. Our study shows that moderate-magnitude events can be preserved in the stratigraphy and exposed by paleoseismic trenching under ideal conditions, for instance, if sedimentation is fast enough and there is no hiatus in deposition. Eventually, the data presented add to the growing body of paleoseismic records containing events of different magnitudes with a large variability in rupture length and coseismic slip.

  13. Increased Speed: 3D Silicon Sensors. Fast Current Amplifiers

    SciTech Connect

    Parker, Sherwood; Kok, Angela; Kenney, Christopher; Jarron, Pierre; Hasi, Jasmine; Despeisse, Matthieu; Da Via, Cinzia; Anelli, Giovanni; /CERN

    2012-05-07

    The authors describe techniques to make fast, sub-nanosecond time resolution solid-state detector systems using sensors with 3D electrodes, current amplifiers, constant-fraction comparators or fast wave-form recorders, and some of the next steps to reach still faster results.

  14. Timing and climatic expression of Dansgaard-Oeschger events in stalagmites from Turkey

    NASA Astrophysics Data System (ADS)

    Fleitmann, D.; Badertscher, S.; Cheng, H.; Edwards, R.

    2011-12-01

    The timing of Dansgaard-Oeschger events (D-O events), also known as Greenland interstadials (GIS), and their climatic and environmental impact in the Eastern Mediterranean is not well constrained. A set of highly-resolved and precisely dated stalagmite oxygen and carbon isotope records from Sofular Cave in northern Turkey cover the last 130 kyr before present almost continously and show D-O events 1-25 in great detail. Rapid climatic changes at the transition into D-O events are marked by a fast ecosystem response within a few decades. The timing of most D-O events in the Sofular time series is broadly consistent with the Hulu Cave (Wang et al., 2001)and other absolutely dated speleothem records, such as the Kleegruobe Cave (Spotl et al., 2006) or Fort Stanton Cave (Asmerom et al., 2010) records. Importantly, the timing is also consistent within age uncertainties with the most recent NGRIP ice core chronology (GICC05; Svenson et al., 2006; 2008). References Asmerom, Y., V. J. Polyak, et al. (2010). "Variable winter moisture in the southwestern United States linked to rapid glacial climate shifts." Nature Geoscience 3(2): 114-117. Spotl, C., A. Mangini, et al. (2006). "Chronology and paleoenvironment of Marine Isotope Stage 3 from two high-elevation speleothems, Austrian Alps." Quaternary Science Reviews 25(9-10): 1127-1136. Svensson, A., K. K. Andersen, et al. (2006). "The Greenland Ice Core Chronology 2005, 15-42 ka. Part 2: comparison to other records." Quaternary Science Reviews 25(23-24): 3258-3267. Svensson, A., K. K. Andersen, et al. (2008). "A 60 000 year Greenland stratigraphic ice core chronology." Climate of the Past 4(1): 47-57.

  15. Manybeam velocimeter for fast surfaces

    SciTech Connect

    Goosman, D.; Avara, G.; Steinmetz, L.; Lai, C.; Perry, S.

    1996-09-01

    For the past 5 years, we have conceived, built and successfully used a new 10 beam laser velocimeter for monitoring velocity vs time histories of fast moving surfaces, and will have a 20 beam capability soon. We conceived a method to multiplex 5 to 10 beams through a single Fabry-Perot interferometer, without losing any light that our equivalently-performing single beam system could use, and with negligible cross- talk. This saves the cost of 16 interferometers, simplifies operation and takes less space than without multiplexing. We devised special efficient light collecting probes, streak cameras that change sweep speed during the course of the record, and a new double cavity interferometer which is better, cheaper and more flexible than our previous versions. With the 10 recorders, we conceived and employ a method of using both a fast and a slow streak camera on each of 5 beams without reducing the light that is available to either camera separately. Five new galvanometrically-driven triggerable CCD streak cameras will be installed soon.

  16. fast-matmul

    SciTech Connect

    Grey Ballard, Austin Benson

    2014-11-26

    This software provides implementations of fast matrix multiplication algorithms. These algorithms perform fewer floating point operations than the classical cubic algorithm. The software uses code generation to automatically implement the fast algorithms based on high-level descriptions. The code serves two general purposes. The first is to demonstrate that these fast algorithms can out-perform vendor matrix multiplication algorithms for modest problem sizes on a single machine. The second is to rapidly prototype many variations of fast matrix multiplication algorithms to encourage future research in this area. The implementations target sequential and shared memory parallel execution.

  17. Fast robust correlation.

    PubMed

    Fitch, Alistair J; Kadyrov, Alexander; Christmas, William J; Kittler, Josef

    2005-08-01

    A new, fast, statistically robust, exhaustive, translational image-matching technique is presented: fast robust correlation. Existing methods are either slow or non-robust, or rely on optimization. Fast robust correlation works by expressing a robust matching surface as a series of correlations. Speed is obtained by computing correlations in the frequency domain. Computational cost is analyzed and the method is shown to be fast. Speed is comparable to conventional correlation and, for large images, thousands of times faster than direct robust matching. Three experiments demonstrate the advantage of the technique over standard correlation.

  18. [Medical aspects of fasting].

    PubMed

    Gavrankapetanović, F

    1997-01-01

    Fasting (arabic-savm) was proclaimed through islam, and thus it is an obligation for Holly Prophet Muhammad s.a.v.s.-Peace be to Him-in the second year after Hijra (in 624 after Milad-born of Isa a.s.). There is a month of fasting-Ramadan-each lunar (hijra) year. So, it was 1415th fasting this year. Former Prophets have brought obligative messages on fasting to their people; so there are also certain forms of fasting with other religions i.e. with Catholics, Jews, Orthodox. These kinds of fasting above differ from muslim fasting, but they also appear obligative. All revelations have brought fasting as obligative. From medical point of view, fasting has two basical components: psychical and physical. Psychical sphere correlate closely with its fundamental ideological message. Allah dz.s. says in Quran: "... Fasting is obligative for you, as it was obligative to your precedents, as to avoid sins; during very few days (II, II, 183 & 184)." Will strength, control of passions, effort and self-discipline makes a pure faithfull person, who purify its mind and body through fasting. Thinking about The Creator is more intensive, character is more solid; and spirit and will get stronger. We will mention the hadith saying: "Essaihune humus saimun!" That means: "Travellers at the Earth are fasters (of my ummet)." The commentary of this hadith, in the Collection of 1001 hadiths (Bin bir hadis), number 485, says: "There are no travelling dervishs or monks in islam; thus there is no such a kind of relligousity in islam. In stead, it is changed by fasting and constant attending of mosque. That was proclaimed as obligation, although there were few cases of travelling in the name of relligousity, like travelling dervishs and sheichs." In this paper, the author discusses medical aspects of fasting and its positive characteristics in the respect of healthy life style and prevention of many sicks. The author mentions positive influence of fasting to certain system and organs of human

  19. Integrative Physiology of Fasting.

    PubMed

    Secor, Stephen M; Carey, Hannah V

    2016-04-01

    Extended bouts of fasting are ingrained in the ecology of many organisms, characterizing aspects of reproduction, development, hibernation, estivation, migration, and infrequent feeding habits. The challenge of long fasting episodes is the need to maintain physiological homeostasis while relying solely on endogenous resources. To meet that challenge, animals utilize an integrated repertoire of behavioral, physiological, and biochemical responses that reduce metabolic rates, maintain tissue structure and function, and thus enhance survival. We have synthesized in this review the integrative physiological, morphological, and biochemical responses, and their stages, that characterize natural fasting bouts. Underlying the capacity to survive extended fasts are behaviors and mechanisms that reduce metabolic expenditure and shift the dependency to lipid utilization. Hormonal regulation and immune capacity are altered by fasting; hormones that trigger digestion, elevate metabolism, and support immune performance become depressed, whereas hormones that enhance the utilization of endogenous substrates are elevated. The negative energy budget that accompanies fasting leads to the loss of body mass as fat stores are depleted and tissues undergo atrophy (i.e., loss of mass). Absolute rates of body mass loss scale allometrically among vertebrates. Tissues and organs vary in the degree of atrophy and downregulation of function, depending on the degree to which they are used during the fast. Fasting affects the population dynamics and activities of the gut microbiota, an interplay that impacts the host's fasting biology. Fasting-induced gene expression programs underlie the broad spectrum of integrated physiological mechanisms responsible for an animal's ability to survive long episodes of natural fasting. PMID:27065168

  20. Stress the Local Angle...Keep the Yearbook Currently Eventful.

    ERIC Educational Resources Information Center

    Stano, Randy

    1980-01-01

    Suggests that while current events should be recorded in school yearbooks, the local angle should be stressed. Provides illustrations of how this might be done with such topics as gasoline prices, inflation, foreign events, and political campaigns. (TJ)

  1. An automated cross-correlation based event detection technique and its application to surface passive data set

    USGS Publications Warehouse

    Forghani-Arani, Farnoush; Behura, Jyoti; Haines, Seth S.; Batzle, Mike

    2013-01-01

    In studies on heavy oil, shale reservoirs, tight gas and enhanced geothermal systems, the use of surface passive seismic data to monitor induced microseismicity due to the fluid flow in the subsurface is becoming more common. However, in most studies passive seismic records contain days and months of data and manually analysing the data can be expensive and inaccurate. Moreover, in the presence of noise, detecting the arrival of weak microseismic events becomes challenging. Hence, the use of an automated, accurate and computationally fast technique for event detection in passive seismic data is essential. The conventional automatic event identification algorithm computes a running-window energy ratio of the short-term average to the long-term average of the passive seismic data for each trace. We show that for the common case of a low signal-to-noise ratio in surface passive records, the conventional method is not sufficiently effective at event identification. Here, we extend the conventional algorithm by introducing a technique that is based on the cross-correlation of the energy ratios computed by the conventional method. With our technique we can measure the similarities amongst the computed energy ratios at different traces. Our approach is successful at improving the detectability of events with a low signal-to-noise ratio that are not detectable with the conventional algorithm. Also, our algorithm has the advantage to identify if an event is common to all stations (a regional event) or to a limited number of stations (a local event). We provide examples of applying our technique to synthetic data and a field surface passive data set recorded at a geothermal site.

  2. Personal miniature electrophysiological tape recorder

    NASA Astrophysics Data System (ADS)

    Green, H.

    1981-11-01

    The use of a personal miniature electrophysiological tape recorder to measure the physiological reactions of space flight personnel to space flight stress and weightlessness is described. The Oxford Instruments Medilog recorder, a battery-powered, four-channel cassette tape recorder with 24 hour endurance is carried on the person and will record EKG, EOG, EEG, and timing and event markers. The data will give information about heart rate and morphology changes, and document adaptation to zero gravity on the part of subjects who, unlike highly trained astronauts, are more representative of the normal population than were the subjects of previous space flight studies.

  3. Personal miniature electrophysiological tape recorder

    NASA Technical Reports Server (NTRS)

    Green, H.

    1981-01-01

    The use of a personal miniature electrophysiological tape recorder to measure the physiological reactions of space flight personnel to space flight stress and weightlessness is described. The Oxford Instruments Medilog recorder, a battery-powered, four-channel cassette tape recorder with 24 hour endurance is carried on the person and will record EKG, EOG, EEG, and timing and event markers. The data will give information about heart rate and morphology changes, and document adaptation to zero gravity on the part of subjects who, unlike highly trained astronauts, are more representative of the normal population than were the subjects of previous space flight studies.

  4. Synopsis of a computer program designed to interface a personal computer with the fast data acquisition system of a time-of-flight mass spectrometer

    NASA Technical Reports Server (NTRS)

    Bechtel, R. D.; Mateos, M. A.; Lincoln, K. A.

    1988-01-01

    Briefly described are the essential features of a computer program designed to interface a personal computer with the fast, digital data acquisition system of a time-of-flight mass spectrometer. The instrumentation was developed to provide a time-resolved analysis of individual vapor pulses produced by the incidence of a pulsed laser beam on an ablative material. The high repetition rate spectrometer coupled to a fast transient recorder captures complete mass spectra every 20 to 35 microsecs, thereby providing the time resolution needed for the study of this sort of transient event. The program enables the computer to record the large amount of data generated by the system in short time intervals, and it provides the operator the immediate option of presenting the spectral data in several different formats. Furthermore, the system does this with a high degree of automation, including the tasks of mass labeling the spectra and logging pertinent instrumental parameters.

  5. Fast protein folding kinetics

    PubMed Central

    Gelman, Hannah; Gruebele, Martin

    2014-01-01

    Fast folding proteins have been a major focus of computational and experimental study because they are accessible to both techniques: they are small and fast enough to be reasonably simulated with current computational power, but have dynamics slow enough to be observed with specially developed experimental techniques. This coupled study of fast folding proteins has provided insight into the mechanisms which allow some proteins to find their native conformation well less than 1 ms and has uncovered examples of theoretically predicted phenomena such as downhill folding. The study of fast folders also informs our understanding of even “slow” folding processes: fast folders are small, relatively simple protein domains and the principles that govern their folding also govern the folding of more complex systems. This review summarizes the major theoretical and experimental techniques used to study fast folding proteins and provides an overview of the major findings of fast folding research. Finally, we examine the themes that have emerged from studying fast folders and briefly summarize their application to protein folding in general as well as some work that is left to do. PMID:24641816

  6. fastKDE

    SciTech Connect

    O'Brien, Travis A.; Kashinath, Karthik

    2015-05-22

    This software implements the fast, self-consistent probability density estimation described by O'Brien et al. (2014, doi: ). It uses a non-uniform fast Fourier transform technique to reduce the computational cost of an objective and self-consistent kernel density estimation method.

  7. Fast and effective?

    PubMed

    Trueland, Jennifer

    2013-12-18

    The 5.2 diet involves two days of fasting each week. It is being promoted as the key to sustained weight loss, as well as wider health benefits, despite the lack of evidence on the long-term effects. Nurses need to support patients who wish to try intermittent fasting. PMID:24345130

  8. A fast dynamic mode in rare earth based glasses

    NASA Astrophysics Data System (ADS)

    Zhao, L. Z.; Xue, R. J.; Zhu, Z. G.; Ngai, K. L.; Wang, W. H.; Bai, H. Y.

    2016-05-01

    Metallic glasses (MGs) usually exhibit only slow β-relaxation peak, and the signature of the fast dynamic is challenging to be observed experimentally in MGs. We report a general and unusual fast dynamic mode in a series of rare earth based MGs manifested as a distinct fast β'-relaxation peak in addition to slow β-relaxation and α-relaxation peaks. We show that the activation energy of the fast β'-relaxation is about 12RTg and is equivalent to the activation of localized flow event. The coupling of these dynamic processes as well as their relationship with glass transition and structural heterogeneity is discussed.

  9. Creating Special Events

    ERIC Educational Resources Information Center

    deLisle, Lee

    2009-01-01

    "Creating Special Events" is organized as a systematic approach to festivals and events for students who seek a career in event management. This book looks at the evolution and history of festivals and events and proceeds to the nuts and bolts of event management. The book presents event management as the means of planning, organizing, directing,…

  10. Gingival status during prolonged fasting for weight loss.

    PubMed

    Squire, C F; Costley, J M

    1976-02-01

    Nineteen obese patients were observed during a prolonged period of fasting for weight loss. The period of fasting ranged from 15 to 71 days. The patients consumed a dose of certain vitamins and minerals with 2 liters of water per day. No effort was made to alter the patient at the beginning and termination of the fasting period. At the time of original recording the Plaque and Gingival Index correlated directly. As the fasting period lengthened, there was a decrease in the Plaque Index scores but the Ginival Index scores increased considerably. This is an opposite correlation to what one would expect in individuals maintained on an adequate diet. PMID:1062556

  11. El Nino-like events during Miocene

    SciTech Connect

    Casey, R.E.; Nelson, C.O.; Weinheimer, A.L.; Oeth, P.A.; Swanson, R.J.

    1988-03-01

    El Nino-like events have been recorded from the Miocene laminated siliceous facies of the Monterey Formation. These El Nino-like Miocene events are compared to El Nino events recorded from Holocene varved sediments deposited within the anoxic Santa Barbara basin. Strong El Nino events can be recognized from Holocene Santa Barbara basin sediments by increases in radiolarian flux to the sea floor during those events. For the last 100-plus years, frequency of strong El Ninos has been on the order of one extremely strong event about every 100 years, and one easily recognizable event about every 18 years. Frequencies in the laminated (varved) Miocene range from about every 4-5 years to over 20 years. The higher frequencies occur within generally warm intervals and the lower frequencies within generally cold intervals. Perhaps the frequencies of these events may, in fact, be an important indicator in determining whether the intervals were cold or warm. Reconstructions of the paleo-California Current system during El Nino-like periods have been made for the west coast from the Gulf of California to northern California. Strong El Nino-like events occurred 5.5 and 8 Ma, and a strong anti-El Nino-like event occurred at about 6.5 Ma. Evidence from the 5.5 and 8 Ma events combined with other evidence suggests that modern El Ninos, similar to today's, were initiated at 5.5 Ma or earlier.

  12. The shoulder distraction force in cricket fast bowling.

    PubMed

    Stuelcken, Max C; Ferdinands, René E D; Ginn, Karen A; Sinclair, Peter J

    2010-08-01

    This preliminary study aimed to quantify the magnitude of the peak shoulder distraction force during the bowling action of female cricket fast bowlers. An eight camera Vicon motion analysis system operating at 120 Hz recorded the fast bowling actions of 18 Australian female fast bowlers. A three segment inverse solution model of the bowling arm was used to calculate the shoulder distraction force. A large peak shoulder distraction force was recorded during the early stages of the follow-through of the bowling action. When normalized for body weight, the distraction force was within the range of values reported for baseball and softball pitchers, who are considered to be at high risk of shoulder injury. Therefore, the relative importance of the peak shoulder distraction force in the fast bowling action for the development of shoulder pain in female cricket fast bowlers warrants further investigation. PMID:20841630

  13. The shoulder distraction force in cricket fast bowling.

    PubMed

    Stuelcken, Max C; Ferdinands, René E D; Ginn, Karen A; Sinclair, Peter J

    2010-08-01

    This preliminary study aimed to quantify the magnitude of the peak shoulder distraction force during the bowling action of female cricket fast bowlers. An eight camera Vicon motion analysis system operating at 120 Hz recorded the fast bowling actions of 18 Australian female fast bowlers. A three segment inverse solution model of the bowling arm was used to calculate the shoulder distraction force. A large peak shoulder distraction force was recorded during the early stages of the follow-through of the bowling action. When normalized for body weight, the distraction force was within the range of values reported for baseball and softball pitchers, who are considered to be at high risk of shoulder injury. Therefore, the relative importance of the peak shoulder distraction force in the fast bowling action for the development of shoulder pain in female cricket fast bowlers warrants further investigation.

  14. Reusable fast opening switch

    DOEpatents

    Van Devender, John P.; Emin, David

    1986-01-01

    A reusable fast opening switch for transferring energy, in the form of a high power pulse, from an electromagnetic storage device such as an inductor into a load. The switch is efficient, compact, fast and reusable. The switch comprises a ferromagnetic semiconductor which undergoes a fast transition between conductive and insulating states at a critical temperature and which undergoes the transition without a phase change in its crystal structure. A semiconductor such as europium rich europhous oxide, which undergoes a conductor to insulator transition when it is joule heated from its conductor state, can be used to form the switch.

  15. Reusable fast opening switch

    DOEpatents

    Van Devender, J.P.; Emin, D.

    1983-12-21

    A reusable fast opening switch for transferring energy, in the form of a high power pulse, from an electromagnetic storage device such as an inductor into a load. The switch is efficient, compact, fast and reusable. The switch comprises a ferromagnetic semiconductor which undergoes a fast transition between conductive and metallic states at a critical temperature and which undergoes the transition without a phase change in its crystal structure. A semiconductor such as europium rich europhous oxide, which undergoes a conductor to insulator transition when it is joule heated from its conductor state, can be used to form the switch.

  16. fast-matmul

    2014-11-26

    This software provides implementations of fast matrix multiplication algorithms. These algorithms perform fewer floating point operations than the classical cubic algorithm. The software uses code generation to automatically implement the fast algorithms based on high-level descriptions. The code serves two general purposes. The first is to demonstrate that these fast algorithms can out-perform vendor matrix multiplication algorithms for modest problem sizes on a single machine. The second is to rapidly prototype many variations of fastmore » matrix multiplication algorithms to encourage future research in this area. The implementations target sequential and shared memory parallel execution.« less

  17. Fast Breeder Reactor studies

    SciTech Connect

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  18. 26 CFR 1.7701(l)-3 - Recharacterizing financing arrangements involving fast-pay stock.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... paragraph (g)(2)(ii) applies must include a statement in its books and records identifying each fast-pay... paragraph (g)(2) for periods before January 1, 2000. Example 1. Fast-pay arrangement recharacterized under...' portion of the note. For purposes of paragraph (g)(2)(i)(A) of this section, the fast-pay...

  19. 26 CFR 1.7701(l)-3 - Recharacterizing financing arrangements involving fast-pay stock.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... paragraph (g)(2)(ii) applies must include a statement in its books and records identifying each fast-pay... paragraph (g)(2) for periods before January 1, 2000. Example 1. Fast-pay arrangement recharacterized under...' portion of the note. For purposes of paragraph (g)(2)(i)(A) of this section, the fast-pay...

  20. Effects of incense on brain function: evaluation using electroencephalograms and event-related potentials.

    PubMed

    Iijima, Mutsumi; Osawa, Mikio; Nishitani, Nobuyuki; Iwata, Makoto

    2009-01-01

    To evaluate the effect of the odor of incense on brain activity, electroencephalograms (EEGs) and event-related potentials (ERPs) in a push/wait paradigm were recorded in 10 healthy adults (aged 23-39 years) with normal olfactory function. EEG was recorded from 21 electrodes on the scalp, according to the International 10-20 system, and EEG power spectra were calculated by fast Fourier transform for 3 min before and during odor presentation. ERPs were recorded from 15 electrodes on the scalp before, during and after exposure to incense with intervals of 10 min. In a push/wait paradigm, two Japanese words, 'push' as the go stimulus and 'wait' as the no-go stimulus, appeared randomly on a CRT screen with equal probability. The subjects were instructed to push a button whenever the 'push' signal appeared. Fast alpha activity (10-13 Hz) increased significantly in bilateral posterior regions during incense exposure compared to that during rose oil exposure. The peak amplitudes of no-go P3 at Fz and Cz were significantly greater during incense inhalation. The latencies of go P3 and no-go P3, and the amplitude and latencies of no-go N2 did not change by exposure to the odors of both incense, rose and odorless air. These results suggest that the odor of incense may enhance cortical activities and the function of inhibitory processing of motor response. PMID:19325250

  1. Effects of incense on brain function: evaluation using electroencephalograms and event-related potentials.

    PubMed

    Iijima, Mutsumi; Osawa, Mikio; Nishitani, Nobuyuki; Iwata, Makoto

    2009-01-01

    To evaluate the effect of the odor of incense on brain activity, electroencephalograms (EEGs) and event-related potentials (ERPs) in a push/wait paradigm were recorded in 10 healthy adults (aged 23-39 years) with normal olfactory function. EEG was recorded from 21 electrodes on the scalp, according to the International 10-20 system, and EEG power spectra were calculated by fast Fourier transform for 3 min before and during odor presentation. ERPs were recorded from 15 electrodes on the scalp before, during and after exposure to incense with intervals of 10 min. In a push/wait paradigm, two Japanese words, 'push' as the go stimulus and 'wait' as the no-go stimulus, appeared randomly on a CRT screen with equal probability. The subjects were instructed to push a button whenever the 'push' signal appeared. Fast alpha activity (10-13 Hz) increased significantly in bilateral posterior regions during incense exposure compared to that during rose oil exposure. The peak amplitudes of no-go P3 at Fz and Cz were significantly greater during incense inhalation. The latencies of go P3 and no-go P3, and the amplitude and latencies of no-go N2 did not change by exposure to the odors of both incense, rose and odorless air. These results suggest that the odor of incense may enhance cortical activities and the function of inhibitory processing of motor response.

  2. Cortical Specializations Underlying Fast Computations

    PubMed Central

    Volgushev, Maxim

    2016-01-01

    The time course of behaviorally relevant environmental events sets temporal constraints on neuronal processing. How does the mammalian brain make use of the increasingly complex networks of the neocortex, while making decisions and executing behavioral reactions within a reasonable time? The key parameter determining the speed of computations in neuronal networks is a time interval that neuronal ensembles need to process changes at their input and communicate results of this processing to downstream neurons. Theoretical analysis identified basic requirements for fast processing: use of neuronal populations for encoding, background activity, and fast onset dynamics of action potentials in neurons. Experimental evidence shows that populations of neocortical neurons fulfil these requirements. Indeed, they can change firing rate in response to input perturbations very quickly, within 1 to 3 ms, and encode high-frequency components of the input by phase-locking their spiking to frequencies up to 300 to 1000 Hz. This implies that time unit of computations by cortical ensembles is only few, 1 to 3 ms, which is considerably faster than the membrane time constant of individual neurons. The ability of cortical neuronal ensembles to communicate on a millisecond time scale allows for complex, multiple-step processing and precise coordination of neuronal activity in parallel processing streams, while keeping the speed of behavioral reactions within environmentally set temporal constraints. PMID:25689988

  3. Discovery with FAST

    NASA Astrophysics Data System (ADS)

    Wilkinson, P.

    2016-02-01

    FAST offers "transformational" performance well-suited to finding new phenomena - one of which might be polarised spectral transients. But discoveries will only be made if "the system" provides its users with the necessary opportunities. In addition to designing in as much observational flexibility as possible, FAST should be operated with a philosophy which maximises its "human bandwidth". This band includes the astronomers of tomorrow - many of whom not have yet started school or even been born.

  4. Fast Vegetational Responses to Late-Glacial Climate Change

    NASA Astrophysics Data System (ADS)

    Williams, J. W.; Post, D. M.; Cwynar, L. C.; Lotter, A. F.; Levesque, A. J.

    2001-12-01

    How rapidly can natural ecosystems respond to rapid climate change? This question can be addressed by studying paired paleoecological and paleoclimatological records spanning the last deglaciation. Between 16 and 10 ka, abrupt climatic oscillations (e.g. Younger Dryas, Gerzensee/Killarney Oscillations) interrupted the general warming trend. Rates of climate change during these events were as fast or faster than projected rates of change for this century. We compiled a dozen high-resolution lacustrine records in North America and Europe with a pollen record and independent climatic proxy, a clear Younger Dryas signal, and good age control. Cross-correlation analysis suggests that vegetation responded rapidly to late-glacial climate change, with significant changes in vegetation composition occurring within the lifespan of individual trees. At all sites, vegetation lagged climate by less than 200 years, and at two-thirds of the sites, the initial vegetational response occurred within 100 years. The finding of rapid vegetational responses is consistent across sites and continents, and is similar to the 100-200 year response times predicted by gap-scale forest models. Likely mechanisms include 1) increased susceptibility of mature trees to disturbances such as fire, wind, and disease, thereby opening up gaps for colonization, 2) the proximity of these sites to late-glacial treeline, where climate may directly control plant population densities and range limits, 3) the presence of herbaceous taxa with short generation times in these plant communities, and 4) rapid migration due to rare long-distance seed dispersals. Our results are consistent with reports that plant ranges are already shifting in response to recent climate change, and suggest that these shifts will persist for the next several centuries. Widespread changes in plant distributions may affect surface-atmosphere interactions and will challenge attempts to manage ecosystems and conserve biodiversity.

  5. Empirical law for fault-creep events

    USGS Publications Warehouse

    Crough, S.T.; Burford, R.O.

    1977-01-01

    Fault-creep events measured on the San Andreas and related faults near Hollister, California, can be described by a rheological model consisting of a spring, power-law dashpotand sliding block connected in series. An empirical creep-event law, derived from many creep-event records analyzed within the constraints of the model, provides a remarkably simple and accurate representation of creep-event behavior. The empirical creep law is expressed by the equation: D(t)= Df [1-1/{ct(n-1)Dfn-1+1}/(n-1)] where D is the value of displacement at time t following the onset of an event, Df is the final equilibrium value of the event displacementand C is a proportionality constant. This discovery should help determine whether the time-displacement character of creep events is controlled by the material properties of fault gouge, or by other parameters. ?? 1977.

  6. Assessing Special Events.

    ERIC Educational Resources Information Center

    Neff, Bonita Dostal

    Special events defined as being "newsworthy events" are becoming a way of American life. They are also a means for making a lot of money. Examples of special events that are cited most frequently are often the most minor of events; e.g., the open house, the new business opening day gala, or a celebration of some event in an organization. Little…

  7. Oceanic oxygenation events in the anoxic Ediacaran ocean.

    PubMed

    Sahoo, S K; Planavsky, N J; Jiang, G; Kendall, B; Owens, J D; Wang, X; Shi, X; Anbar, A D; Lyons, T W

    2016-09-01

    The ocean-atmosphere system is typically envisioned to have gone through a unidirectional oxygenation with significant oxygen increases in the earliest (ca. 635 Ma), middle (ca. 580 Ma), or late (ca. 560 Ma) Ediacaran Period. However, temporally discontinuous geochemical data and the patchy metazoan fossil record have been inadequate to chart the details of Ediacaran ocean oxygenation, raising fundamental debates about the timing of ocean oxygenation, its purported unidirectional rise, and its causal relationship, if any, with the evolution of early animal life. To better understand the Ediacaran ocean redox evolution, we have conducted a multi-proxy paleoredox study of a relatively continuous, deep-water section in South China that was paleogeographically connected with the open ocean. Iron speciation and pyrite morphology indicate locally euxinic (anoxic and sulfidic) environments throughout the Ediacaran in this section. In the same rocks, redox sensitive element enrichments and sulfur isotope data provide evidence for multiple oceanic oxygenation events (OOEs) in a predominantly anoxic global Ediacaran-early Cambrian ocean. This dynamic redox landscape contrasts with a recent view of a redox-static Ediacaran ocean without significant change in oxygen content. The duration of the Ediacaran OOEs may be comparable to those of the oceanic anoxic events (OAEs) in otherwise well-oxygenated Phanerozoic oceans. Anoxic events caused mass extinctions followed by fast recovery in biologically diversified Phanerozoic oceans. In contrast, oxygenation events in otherwise ecologically monotonous anoxic Ediacaran-early Cambrian oceans may have stimulated biotic innovations followed by prolonged evolutionary stasis.

  8. Oceanic oxygenation events in the anoxic Ediacaran ocean.

    PubMed

    Sahoo, S K; Planavsky, N J; Jiang, G; Kendall, B; Owens, J D; Wang, X; Shi, X; Anbar, A D; Lyons, T W

    2016-09-01

    The ocean-atmosphere system is typically envisioned to have gone through a unidirectional oxygenation with significant oxygen increases in the earliest (ca. 635 Ma), middle (ca. 580 Ma), or late (ca. 560 Ma) Ediacaran Period. However, temporally discontinuous geochemical data and the patchy metazoan fossil record have been inadequate to chart the details of Ediacaran ocean oxygenation, raising fundamental debates about the timing of ocean oxygenation, its purported unidirectional rise, and its causal relationship, if any, with the evolution of early animal life. To better understand the Ediacaran ocean redox evolution, we have conducted a multi-proxy paleoredox study of a relatively continuous, deep-water section in South China that was paleogeographically connected with the open ocean. Iron speciation and pyrite morphology indicate locally euxinic (anoxic and sulfidic) environments throughout the Ediacaran in this section. In the same rocks, redox sensitive element enrichments and sulfur isotope data provide evidence for multiple oceanic oxygenation events (OOEs) in a predominantly anoxic global Ediacaran-early Cambrian ocean. This dynamic redox landscape contrasts with a recent view of a redox-static Ediacaran ocean without significant change in oxygen content. The duration of the Ediacaran OOEs may be comparable to those of the oceanic anoxic events (OAEs) in otherwise well-oxygenated Phanerozoic oceans. Anoxic events caused mass extinctions followed by fast recovery in biologically diversified Phanerozoic oceans. In contrast, oxygenation events in otherwise ecologically monotonous anoxic Ediacaran-early Cambrian oceans may have stimulated biotic innovations followed by prolonged evolutionary stasis. PMID:27027776

  9. Solar Eruptive Events

    NASA Technical Reports Server (NTRS)

    Holman, Gordon D.

    2012-01-01

    It s long been known that the Sun plays host to the most energetic explosions in the solar system. But key insights into the forms that energy takes have only recently become available. Solar flares have been phenomena of both academic and practical interest since their discovery in 1859. From the academic point of view, they are the nearest events for studying the explosive release of energy in astrophysical magnetized plasmas. From the practical point of view, they disrupt communication channels on Earth, from telegraph communications in 1859 to radio and television signals today. Flares also wreak havoc on the electrical power grid, satellite operations, and GPS signals, and energetic charged particles and radiation are dangerous to passengers on high-altitude polar flights and to astronauts. Flares are not the only explosive phenomena on the Sun. More difficult to observe but equally energetic are the large coronal mass ejections (CMEs), the ejection of up to ten billion tons of magnetized plasma into the solar wind at speeds that can exceed 1000 km/s. CMEs are primarily observed from the side, with coronagraphs that block out the bright disk of the Sun and lower solar atmosphere so that light scattered from the ejected mass can be seen. Major geomagnetic storms are now known to arise from the interaction of CMEs with Earth's magnetosphere. Solar flares are observed without CMEs, and CMEs are observed without flares. The two phenomena often occur together, however, and almost always do in the case of large flares and fast CMEs. The term solar eruptive event refers to the combination of a flare and a CME. Solar eruptive events generate a lot of heat: They can heat plasma to temperatures as high at 50 million Kelvin, producing radiation across the electromagnetic spectrum. But that s not all. A fascinating aspect of solar eruptive events is the acceleration of electrons and ions to suprathermal often relativistic energies. The accelerated particles are primarily

  10. Fast dynamic processes of solar radiation

    SciTech Connect

    Tomson, Teolan

    2010-02-15

    This paper studies dynamic processes of fast-alternating solar radiation which are assessed by alternation of clouds. Most attention is devoted to clouds of type Cumulus Humilis, identified through visual recognition and/or a specially constructed automatic sensor. One second sampling period was used. Recorded data series were analyzed with regard to duration of illuminated 'windows' between shadows, their stochastic intervals, fronts and the magnitude of increments of solar irradiance. (author)