Science.gov

Sample records for 1-year time horizon

  1. Time Horizon and Social Scale in Communication

    NASA Astrophysics Data System (ADS)

    Krantz, D. H.

    2010-12-01

    In 2009 our center (CRED) published a first version of The Psychology of Climate Change Communication. In it, we attempted to summarize facts and concepts from psychological research that could help guide communication. While this work focused on climate change, most of the ideas are at least partly applicable for communication about a variety of natural hazards. Of the many examples in this guide, I mention three. Single-action bias is the human tendency to stop considering further actions that might be needed to deal with a given hazard, once a single action has been taken. Another example is the importance of group affiliation in motivating voluntary contributions to joint action. A third concerns the finding that group participation enhances understanding of probabilistic concepts and promotes action in the face of uncertainty. One current research direction, which goes beyond those included in the above publication, focuses on how time horizons arise in the thinking of individuals and groups, and how these time horizons might influence hazard preparedness. On the one hand, individuals sometimes appear impatient, organizations look for immediate results, and officials fail to look beyond the next election cycle. Yet under some laboratory conditions and in some subcultures, a longer time horizon is adopted. We are interested in how time horizon is influenced by group identity and by the very architecture of planning and decision making. Institutional changes, involving long-term contractual relationships among communities, developers, insurers, and governments, could greatly increase resilience in the face of natural hazards. Communication about hazards, in the context of such long-term contractual relationships might look very different from communication that is first initiated by immediate threat. Another new direction concerns the social scale of institutions and of communication about hazards. Traditionally, insurance contracts share risk among a large

  2. Microbial Community Composition, Functions, and Activities in the Gulf of Mexico 1 Year after the Deepwater Horizon Accident.

    PubMed

    Yergeau, Etienne; Maynard, Christine; Sanschagrin, Sylvie; Champagne, Julie; Juck, David; Lee, Kenneth; Greer, Charles W

    2015-09-01

    Several studies have assessed the effects of the released oil on microbes, either during or immediately after the Deepwater Horizon accident. However, little is known about the potential longer-term persistent effects on microbial communities and their functions. In this study, one water column station near the wellhead (3.78 km southwest of the wellhead), one water column reference station outside the affected area (37.77 km southeast of the wellhead), and deep-sea sediments near the wellhead (3.66 km southeast of the wellhead) were sampled 1 year after the capping of the well. In order to analyze microbial community composition, function, and activity, we used metagenomics, metatranscriptomics, and mineralization assays. Mineralization of hexadecane was significantly higher at the wellhead station at a depth of ∼1,200 m than at the reference station. Community composition based on taxonomical or functional data showed that the samples taken at a depth of ∼1,200 m were significantly more dissimilar between the stations than at other depths (surface, 100 m, 750 m, and >1,500 m). Both Bacteria and Archaea showed reduced activity at depths of ∼1,200 m when the wellhead station was compared to the reference station, and their activity was significantly higher in surficial sediments than in 10-cm sediments. Surficial sediments also harbored significantly different active genera than did 5- and 10-cm sediments. For the remaining microbial parameters assessed, no significant differences could be observed between the wellhead and reference stations and between surface and 5- to 10-cm-deep sediments. PMID:26092461

  3. Microbial Community Composition, Functions, and Activities in the Gulf of Mexico 1 Year after the Deepwater Horizon Accident

    PubMed Central

    Yergeau, Etienne; Maynard, Christine; Sanschagrin, Sylvie; Champagne, Julie; Juck, David; Lee, Kenneth

    2015-01-01

    Several studies have assessed the effects of the released oil on microbes, either during or immediately after the Deepwater Horizon accident. However, little is known about the potential longer-term persistent effects on microbial communities and their functions. In this study, one water column station near the wellhead (3.78 km southwest of the wellhead), one water column reference station outside the affected area (37.77 km southeast of the wellhead), and deep-sea sediments near the wellhead (3.66 km southeast of the wellhead) were sampled 1 year after the capping of the well. In order to analyze microbial community composition, function, and activity, we used metagenomics, metatranscriptomics, and mineralization assays. Mineralization of hexadecane was significantly higher at the wellhead station at a depth of ∼1,200 m than at the reference station. Community composition based on taxonomical or functional data showed that the samples taken at a depth of ∼1,200 m were significantly more dissimilar between the stations than at other depths (surface, 100 m, 750 m, and >1,500 m). Both Bacteria and Archaea showed reduced activity at depths of ∼1,200 m when the wellhead station was compared to the reference station, and their activity was significantly higher in surficial sediments than in 10-cm sediments. Surficial sediments also harbored significantly different active genera than did 5- and 10-cm sediments. For the remaining microbial parameters assessed, no significant differences could be observed between the wellhead and reference stations and between surface and 5- to 10-cm-deep sediments. PMID:26092461

  4. Horizons versus singularities in spherically symmetric space-times

    SciTech Connect

    Bronnikov, K. A.; Elizalde, E.; Odintsov, S. D.; Zaslavskii, O. B.

    2008-09-15

    We discuss different kinds of Killing horizons possible in static, spherically symmetric configurations and recently classified as 'usual', 'naked', and 'truly naked' ones depending on the near-horizon behavior of transverse tidal forces acting on an extended body. We obtain the necessary conditions for the metric to be extensible beyond a horizon in terms of an arbitrary radial coordinate and show that all truly naked horizons, as well as many of those previously characterized as naked and even usual ones, do not admit an extension and therefore must be considered as singularities. Some examples are given, showing which kinds of matter are able to create specific space-times with different kinds of horizons, including truly naked ones. Among them are fluids with negative pressure and scalar fields with a particular behavior of the potential. We also discuss horizons and singularities in Kantowski-Sachs spherically symmetric cosmologies and present horizon regularity conditions in terms of an arbitrary time coordinate and proper (synchronous) time. It turns out that horizons of orders 2 and higher occur in infinite proper times in the past or future, but one-way communication with regions beyond such horizons is still possible.

  5. The WSMR Timing System: Toward New Horizons

    NASA Technical Reports Server (NTRS)

    Gilbert, William A.; Stimets, Bob

    1996-01-01

    In 1991, White Sands Missile Range (WSMR) initiated a modernization program for its range timing system. The main focus of this modernization program was to develop a system that was highly accurate, easy to maintain, and portable. The logical decision at the time was to develop a system based solely on Global Positioning System (GPS) technology. Since that time, wsmr has changed its philosophy on how GPS would be utilized for the timing system. This paper will describe WSMR's initial modernization plans for its range timing system and how certain events have led to a modification of these plans.

  6. Time Horizons, Discounting, and Intertemporal Choice

    ERIC Educational Resources Information Center

    Streich, Philip; Levy, Jack S.

    2007-01-01

    Although many decisions involve a stream of payoffs over time, political scientists have given little attention to how actors make the required tradeoffs between present and future payoffs, other than applying the standard exponential discounting model from economics. After summarizing the basic discounting model, we identify some of its leading…

  7. Forecasting geomagnetic activity at monthly and annual horizons: Time series models

    NASA Astrophysics Data System (ADS)

    Reikard, Gordon

    2015-10-01

    Most of the existing work on forecasting geomagnetic activity has been over short intervals, on the order of hours or days. However, it is also of interest to predict over longer horizons, ranging from months to years. Forecasting tests are run for the Aa index, which begins in 1868 and provides the longest continuous records of geomagnetic activity. This series is challenging to forecast. While it exhibits cycles at 11-22 years, the amplitude and period of the cycles varies over time. There is also evidence of discontinuous trending: the slope and direction of the trend change repeatedly. Further, at the monthly resolution, the data exhibits nonlinear variability, with intermittent large outliers. Several types of models are tested: regressions, neural networks, a frequency domain algorithm, and combined models. Forecasting tests are run at horizons of 1-11 years using the annual data, and 1-12 months using the monthly data. At the 1-year horizon, the mean errors are in the range of 13-17 percent while the median errors are in the range of 10-14 percent. The accuracy of the models deteriorates at longer horizons. At 5 years, the mean errors lie in the range of 21-23 percent, and at 11 years, 23-25 percent. At the 1 year horizon, the most accurate forecast is achieved by a combined model, but over longer horizons (2-11 years), the neural net dominates. At the monthly resolution, the mean errors are in the range of 17-19 percent at 1 month, while the median errors lie in a range of 14-17 percent. The mean error increases to 23-24 percent at 5 months, and 25 percent at 12 months. A model combining frequency and time domain methods is marginally better than regressions and neural networks alone, up to 11 months. The main conclusion is that geomagnetic activity can only be predicted to within a limited threshold of accuracy, over a given range of horizons. This is consistent with the finding of irregular trends and cycles in the annual data and nonlinear variability in

  8. Time machines with the compactly determined Cauchy horizon

    NASA Astrophysics Data System (ADS)

    Krasnikov, S.

    2014-07-01

    The building of a time machine, if possible at all, requires the relevant regions of spacetime to be compact (that is, physically speaking, free from sources of unpredictability such as infinities and singularities). Motivated by this argument we consider the spacetimes with the compactly determined Cauchy horizons (CDCHs), the defining property of which is the compactness of J-(U) ¯∩J+(S0), where U is an open subset of the Cauchy horizon and S0 is a Cauchy surface of the initial globally hyperbolic region Min. The following two facts are established: (1) Min has no globally hyperbolic maximal extension. This means that, by shaping appropriately a precompact portion of a globally hyperbolic region, one can force the Universe to produce either a closed causal curve, or a quasiregular singularity, whichever it abhors less. (2) Before a CDCH is formed a null geodesic appears which infinitely approaches the horizon returning again and again in the same—arbitrarily small—region. The energy of the photon moving on such a geodesic increases with each passage, or at least falls insufficiently fast. As a result, an observer located in the mentioned region would see a bunch of photons passing through his laboratory with the arbitrarily large total energy. We speculate that this phenomenon may have observable consequences.

  9. Age, Time, and Decision Making: From Processing Speed to Global Time Horizons

    PubMed Central

    Löckenhoff, Corinna E.

    2013-01-01

    Time and time perceptions are integral to decision making because any meaningful choice is embedded in a temporal context and requires the evaluation of future preferences and outcomes. The present review examines the influence of chronological age on time perceptions and horizons and discusses implications for decision making across the life span. Time influences and interacts with decision making in multiple ways. Specifically, this review examines the following topic areas: (1) processing speed and decision time, (2) internal clocks and time estimation, (3) mental representations of future time and intertemporal choice, and (4) global time horizons. For each aspect, patterns of age differences and implications for decision strategies and quality are discussed. The conclusion proposes frameworks to integrate different lines of research and identifies promising avenues for future inquiry. PMID:22023567

  10. Deepwater Horizon - Estimating surface oil volume distribution in real time

    NASA Astrophysics Data System (ADS)

    Lehr, B.; Simecek-Beatty, D.; Leifer, I.

    2011-12-01

    Spill responders to the Deepwater Horizon (DWH) oil spill required both the relative spatial distribution and total oil volume of the surface oil. The former was needed on a daily basis to plan and direct local surface recovery and treatment operations. The latter was needed less frequently to provide information for strategic response planning. Unfortunately, the standard spill observation methods were inadequate for an oil spill this size, and new, experimental, methods, were not ready to meet the operational demands of near real-time results. Traditional surface oil estimation tools for large spills include satellite-based sensors to define the spatial extent (but not thickness) of the oil, complemented with trained observers in small aircraft, sometimes supplemented by active or passive remote sensing equipment, to determine surface percent coverage of the 'thick' part of the slick, where the vast majority of the surface oil exists. These tools were also applied to DWH in the early days of the spill but the shear size of the spill prevented synoptic information of the surface slick through the use small aircraft. Also, satellite images of the spill, while large in number, varied considerably in image quality, requiring skilled interpretation of them to identify oil and eliminate false positives. Qualified staff to perform this task were soon in short supply. However, large spills are often events that overcome organizational inertia to the use of new technology. Two prime examples in DWH were the application of hyper-spectral scans from a high-altitude aircraft and more traditional fixed-wing aircraft using multi-spectral scans processed by use of a neural network to determine, respectively, absolute or relative oil thickness. But, with new technology, come new challenges. The hyper-spectral instrument required special viewing conditions that were not present on a daily basis and analysis infrastructure to process the data that was not available at the command

  11. Follow-up of a 1-year media campaign on delay times and ambulance use in suspected acute myocardial infarction.

    PubMed

    Herlitz, J; Blohm, M; Hartford, M; Karlson, B W; Luepker, R; Holmberg, S; Risenfors, M; Wennerblom, B

    1992-02-01

    In order to reduce the delay times from onset of symptoms to arrival in hospital, and increase the use of ambulance in patients with suspected acute myocardial infarction (AMI), a media campaign was initiated in an urban area. An initial 3-week intense campaign was followed by a maintenance phase of 1 year. Delay times and ambulance use during the campaign were compared with the previous 21 months. Among patients admitted to a coronary care unit (CCU) due to suspected AMI, the median delay time was reduced from 3 h to 2 h 40 min and the mean delay time was reduced from 11 h 33 min to 7 h 42 min (P less than 0.001). Among patients with confirmed AMI the median delay time was reduced from 3 h to 2 h 20 min and the mean delay time from 10 h to 6 h 27 min (P less than 0.001). We conclude that a 1-year media campaign can reduce delay times in suspected AMI, and that this effect appears to continue at 1 year, but ambulance use seems to be more difficult to influence. PMID:1555612

  12. 75 FR 79961 - Temporary Suspension of Certain Oil Spill Response Time Requirements To Support Deepwater Horizon...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-21

    ... Gulf of Mexico Deepwater Horizon SONSat the FOSC's request. 75 FR 37712. The rule also confirmed that...; 2050-AG63 Temporary Suspension of Certain Oil Spill Response Time Requirements To Support Deepwater.... Oil Spill Response Resources Return Time Several comments noted concerns about the return of assets...

  13. 75 FR 37712 - Temporary Suspension of Certain Oil Spill Response Time Requirements To Support Deepwater Horizon...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-30

    ...; 2050-AG63 Temporary Suspension of Certain Oil Spill Response Time Requirements To Support Deepwater Horizon Oil Spill of National Significance (SONS) Response AGENCIES: Coast Guard, DHS, and Environmental... Environmental Protection Agency (EPA) temporary interim rule will suspend oil spill response time...

  14. An integral equation representation approach for valuing Russian options with a finite time horizon

    NASA Astrophysics Data System (ADS)

    Jeon, Junkee; Han, Heejae; Kim, Hyeonuk; Kang, Myungjoo

    2016-07-01

    In this paper, we first describe a general solution for the inhomogeneous Black-Scholes partial differential equation with mixed boundary conditions using Mellin transform techniques. Since Russian options with a finite time horizon are usually formulated into the inhomogeneous free-boundary Black-Scholes partial differential equation with a mixed boundary condition, we apply our method to Russian options and derive an integral equation satisfied by Russian options with a finite time horizon. Furthermore, we present some numerical solutions and plots of the integral equation using recursive integration methods and demonstrate the computational accuracy and efficiency of our method compared to other competing approaches.

  15. Horizons and non-local time evolution of quantum mechanical systems

    NASA Astrophysics Data System (ADS)

    Casadio, Roberto

    2015-04-01

    According to general relativity, trapping surfaces and horizons are classical causal structures that arise in systems with sharply defined energy and corresponding gravitational radius. The latter concept can be extended to a quantum mechanical matter state simply by means of the spectral decomposition, which allows one to define an associated "horizon wave-function". Since this auxiliary wave-function contains crucial information about the causal structure of space-time, a new proposal is formulated for the time evolution of quantum systems in order to account for the fundamental classical property that outer observers cannot receive signals from inside a horizon. The simple case of a massive free particle at rest is used throughout the paper as a toy model to illustrate the main ideas.

  16. Parisian ruin over a finite-time horizon

    NASA Astrophysics Data System (ADS)

    Dębicki, Krzysztof; Hashorva, Enkelejd; Ji, LanPeng

    2016-03-01

    For a risk process $R_u(t)=u+ct-X(t), t\\ge 0$, where $u\\ge 0$ is the initial capital, $c>0$ is the premium rate and $X(t),t\\ge 0$ is an aggregate claim process, we investigate the probability of the Parisian ruin \\[ \\mathcal{P}_S(u,T_u)=\\mathbb{P}\\{\\inf_{t\\in[0,S]} \\sup_{s\\in[t,t+T_u]} R_u(s)<0\\}, \\] with a given positive constant $S$ and a positive measurable function $T_u$. We derive asymptotic expansion of $\\mathcal{P}_S(u,T_u)$, as $u\\to\\infty$, for the aggregate claim process $X$ modeled by Gaussian processes. As a by-product, we derive the exact tail asymptotics of the infimum of a standard Brownian motion with drift over a finite-time interval.

  17. Real-time beyond the horizon vessel detection

    NASA Astrophysics Data System (ADS)

    Roarty, Hugh J.; Smith, Michael; Glenn, Scott M.; Barrick, Donald E.

    2013-05-01

    The marine transportation system (MTS) is a vital component of the United States Economy. Waterborne cargo accounts for more than $742 billion of the nation's economy and creates employment for 13 million citizens. A disruption in this system would have far reaching consequences to the security of the country. The US National High Frequency radar network, which comprises 130 radar stations around the country, became operational in May 2009. It provides hourly measurements of surface currents to the US Coast Guard for search and rescue (SAR). This system has the capability of being a dual use system providing information for environmental monitoring as well as vessel position information for maritime security. Real time vessel detection has been implemented at two of the radar stations outside New York Harbor. Several experiments were conducted to see the amount vessel traffic that the radar could capture. The radars were able to detect a majority of the vessels that are reporting via the Automatic Identification System (AIS) as well as 30 percent of mid to large size vessels that are not reporting via AIS. The radars were able to detect vessels out to 60 km from the coast. The addition of a vessel detection capability to the National HF radar network will provide valuable information to maritime security sector. This dual use capability will fill a gap in the current surveillance of US coastal waters. It will also provide longer-range situational awareness necessary to detect and track smaller size vessels in the large vessel clutter.

  18. World-sheet stability, space-time horizons and cosmic censorship

    NASA Astrophysics Data System (ADS)

    Pollock, M. D.

    2014-11-01

    Previously, we have analyzed the stability and supersymmetry of the heterotic superstring world sheet in the background Friedmann space-time generated by a perfect fluid with energy density ρ and pressure p = ( γ - 1) ρ. The world sheet is tachyon-free within the range 2/3 ≤ γ ≤ ∞, and globally supersymmetric in the Minkowski-space limit ρ = ∞, or when γ = 2/3, which is the equation of state for stringy matter and corresponds to the Milne universe, that expands along its apparent horizon. Here, this result is discussed in greater detail, particularly with regard to the question of horizon structure, cosmic censorship, the TCP theorem, and local world-sheet supersymmetry. Also, we consider the symmetric background space-time generated by a static, electrically (or magnetically) charged matter distribution of total mass and charge Q, and containing a radially directed macroscopic string. We find that the effective string mass m satisfies the inequality m 2 ≥ 0, signifying stability, provided that , which corresponds to the Reissner-Nordström black hole. The case of marginal string stability, m 2 = 0, is the extremal solution , which was shown by Gibbons and Hull to be supersymmetric, and has a marginal horizon. If , the horizon disappears, m 2 < 0, and the string becomes unstable.

  19. 41 CFR 302-2.11 - May the 1-year time limitation for completing all aspects of a relocation be extended?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false May the 1-year time... and Property Management Federal Travel Regulation System RELOCATION ALLOWANCES INTRODUCTION 2-EMPLOYEES ELIGIBILITY REQUIREMENTS General Rules Time Limits § 302-2.11 May the 1-year time limitation...

  20. Continuous-Time Mean-Variance Portfolio Selection with Random Horizon

    SciTech Connect

    Yu, Zhiyong

    2013-12-15

    This paper examines the continuous-time mean-variance optimal portfolio selection problem with random market parameters and random time horizon. Treating this problem as a linearly constrained stochastic linear-quadratic optimal control problem, I explicitly derive the efficient portfolios and efficient frontier in closed forms based on the solutions of two backward stochastic differential equations. Some related issues such as a minimum variance portfolio and a mutual fund theorem are also addressed. All the results are markedly different from those in the problem with deterministic exit time. A key part of my analysis involves proving the global solvability of a stochastic Riccati equation, which is interesting in its own right.

  1. HORIZON SENSING

    SciTech Connect

    Larry G. Stolarczyk, Sc.D.

    2002-07-31

    Real-time horizon sensing (HS) on continuous mining (CM) machines is becoming an industry tool. Installation and testing of production-grade HS systems has been ongoing this quarter at Oxbow Mining Company, Monterey Coal Company (EXXON), FMC Trona, Twentymile Coal Company (RAG America), and SASOL Coal. Detailed monitoring of system function, user experience, and mining benefits is ongoing. All horizon sensor components have finished MSHA (United States) and IEC (International) certification.

  2. Incorporating a Time Horizon in Rate-of-Return Estimations: Discounted Cash Flow Model in Electric Transmission Rate Cases

    SciTech Connect

    Chatterjee, Bishu; Sharp, Peter A.

    2006-07-15

    Electric transmission and other rate cases use a form of the discounted cash flow model with a single long-term growth rate to estimate rates of return on equity. It cannot incorporate information about the appropriate time horizon for which analysts' estimates of earnings growth have predictive powers. Only a non-constant growth model can explicitly recognize the importance of the time horizon in an ROE calculation. (author)

  3. Mean-Variance Hedging on Uncertain Time Horizon in a Market with a Jump

    SciTech Connect

    Kharroubi, Idris; Lim, Thomas; Ngoupeyou, Armand

    2013-12-15

    In this work, we study the problem of mean-variance hedging with a random horizon T∧τ, where T is a deterministic constant and τ is a jump time of the underlying asset price process. We first formulate this problem as a stochastic control problem and relate it to a system of BSDEs with a jump. We then provide a verification theorem which gives the optimal strategy for the mean-variance hedging using the solution of the previous system of BSDEs. Finally, we prove that this system of BSDEs admits a solution via a decomposition approach coming from filtration enlargement theory.

  4. Optimal Consumption in a Brownian Model with Absorption and Finite Time Horizon

    SciTech Connect

    Grandits, Peter

    2013-04-15

    We construct {epsilon}-optimal strategies for the following control problem: Maximize E[{integral}{sub [0,{tau})}e{sup -{beta}s} dC{sub s}+e{sup -{beta}{tau}}X{sub {tau}}] , where X{sub t}=x+{mu}t+{sigma}W{sub t}-C{sub t}, {tau}{identical_to}inf{l_brace}t>0|X{sub t}=0{r_brace} Logical-And T, T>0 is a fixed finite time horizon, W{sub t} is standard Brownian motion, {mu}, {sigma} are constants, and C{sub t} describes accumulated consumption until time t. It is shown that {epsilon}-optimal strategies are given by barrier strategies with time-dependent barriers.

  5. A receding horizon scheme for discrete-time polytopic linear parameter varying systems in networked architectures

    NASA Astrophysics Data System (ADS)

    Franzè, Giuseppe; Lucia, Walter; Tedesco, Francesco

    2014-12-01

    This paper proposes a Model Predictive Control (MPC) strategy to address regulation problems for constrained polytopic Linear Parameter Varying (LPV) systems subject to input and state constraints in which both plant measurements and command signals in the loop are sent through communication channels subject to time-varying delays (Networked Control System (NCS)). The results here proposed represent a significant extension to the LPV framework of a recent Receding Horizon Control (RHC) scheme developed for the so-called robust case. By exploiting the parameter availability, the pre-computed sequences of one- step controllable sets inner approximations are less conservative than the robust counterpart. The resulting framework guarantees asymptotic stability and constraints fulfilment regardless of plant uncertainties and time-delay occurrences. Finally, experimental results on a laboratory two-tank test-bed show the effectiveness of the proposed approach.

  6. MARKOV: A methodology for the solution of infinite time horizon MARKOV decision processes

    USGS Publications Warehouse

    Williams, B.K.

    1988-01-01

    Algorithms are described for determining optimal policies for finite state, finite action, infinite discrete time horizon Markov decision processes. Both value-improvement and policy-improvement techniques are used in the algorithms. Computing procedures are also described. The algorithms are appropriate for processes that are either finite or infinite, deterministic or stochastic, discounted or undiscounted, in any meaningful combination of these features. Computing procedures are described in terms of initial data processing, bound improvements, process reduction, and testing and solution. Application of the methodology is illustrated with an example involving natural resource management. Management implications of certain hypothesized relationships between mallard survival and harvest rates are addressed by applying the optimality procedures to mallard population models.

  7. Pluto's Atmosphere at the Time of the New Horizons Flyby from the 29-JUN-2015 Occultation

    NASA Astrophysics Data System (ADS)

    Young, E.; Skrutskie, M.; Wasserman, L.; Howell, R.; Young, L.; Olkin, C.; Buie, M.

    2015-10-01

    Pluto is expected to occult a star on 29-JUN-2015, only two weeks before the scheduled New Horizons flyby on Pluto on 14-JUL-2015. This occultation should be remarkable for several reasons in addition to its synergy with the spacecraft observations. First, the occulted star is by far the brightest ever to be observed in a Pluto occultation: its V-mag is 12.10 ± 0.03, about ten times brighter than Pluto itself. We are deploying a wide array of telescopes to obtain quality lightcurves at 10 Hz, sufficient to resolve vertical atmospheric structure (e.g., gravity waves) at the 2.5-km scale over a range of radii from about 1195 to 1300 km. Second, we plan to obtain lighcurves in infrared wavelengths near 1.7 μm, where the star's H-mag (about 11) is bright enough to provide useful signal-to-noise ratios, albeit at slower cadences near 1 Hz (about two points per scale height). The combination of simultaneous IR and visible wavelength lightcurves should address the decades-old question: is there haze in Pluto's atmosphere, and if so, what is its opacity? New Horizons should image haze layers in reflected light as the occultation quantifies haze extinction in transmitted light: the combination could potentially let us solve for haze phase functions. Third, the current predicted shadow path is centered over much of New Zealand. We plan to deploy three portable telescopes in New Zealand to locations that are candidates for observing central flashes. If successful, these lightcurves can tell us (a) the oblateness of Pluto's atmosphere and (b) the detailed density gradient profile at radii near 1215 km, which (in turn) is a function of trace abundances of CO and CH4 a few tens of km above Pluto's surface. We will report on lightcurves obtained on 29-JUN- 2015, the column abundance of Pluto's atmosphere just two weeks before the New Horizons flyby, the detection (or not) of haze, and - if central flashes are obtained - the oblateness of Pluto's atmosphere.

  8. HORIZON SENSING

    SciTech Connect

    Larry G. Stolarczyk

    2003-03-18

    program began development in 1998 and experienced three major design phases. The final version, termed HS-3, was commissioned in 2000 with the assistance of the DOE-Mining Industry of the Future program, commercialized in 2002, and has been used 14 times in 12 different mines within the United States. The Horizon Sensor has applications in both underground and surface mining operations. This technology is primarily used in the coal industry, but is also used to mine trona and potash. All horizon sensor components have Mine Safety and Health Administration (MSHA) (United States) and IEC (International) certification. Horizon Sensing saves energy by maximizing cutting efficiency, cutting only desired material. This desired material is cleaner fuel, therefore reducing pollutants to the atmosphere when burned and burning more efficiently. Extracting only desired material increases productivity by reducing or eliminating the cleaning step after extraction. Additionally, this technology allows for deeper mining, resulting in more material gained from one location. The remote sensing tool allows workers to operate the machinery away from the hazards of cutting coal, including noise, breathing dust and gases, and coal and rock splintering and outbursts. The HS program has primarily revolved around the development of the technology. However, the end goal of the program has always been the commercialization of the technology and only within the last 2 years of the program has this goal been realized. Real-time horizon sensing on mining machines is becoming an industry tool. Detailed monitoring of system function, user experience, and mining benefits is ongoing.

  9. 41 CFR 302-2.11 - May the 1-year time limitation for completing all aspects of a relocation be extended?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 4 2013-07-01 2012-07-01 true May the 1-year time limitation for completing all aspects of a relocation be extended? 302-2.11 Section 302-2.11 Public Contracts and Property Management Federal Travel Regulation System RELOCATION ALLOWANCES INTRODUCTION 2-EMPLOYEES ELIGIBILITY REQUIREMENTS General...

  10. 41 CFR 302-2.11 - May the 1-year time limitation for completing all aspects of a relocation be extended?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... limitation for completing all aspects of a relocation be extended? 302-2.11 Section 302-2.11 Public Contracts... completing all aspects of a relocation be extended? Yes, the 1-year time limitation for completing all aspects of a relocation may be extended by your Agency for up to one additional year, but only if you...

  11. ''Illusion of control'' in Time-Horizon Minority and Parrondo Games

    NASA Astrophysics Data System (ADS)

    Satinover, J. B.; Sornette, D.

    2007-12-01

    Human beings like to believe they are in control of their destiny. This ubiquitous trait seems to increase motivation and persistence, and is probably evolutionarily adaptive [J.D. Taylor, S.E. Brown, Psych. Bull. 103, 193 (1988); A. Bandura, Self-efficacy: the exercise of control (WH Freeman, New York, 1997)]. But how good really is our ability to control? How successful is our track record in these areas? There is little understanding of when and under what circumstances we may over-estimate [E. Langer, J. Pers. Soc. Psych. 7, 185 (1975)] or even lose our ability to control and optimize outcomes, especially when they are the result of aggregations of individual optimization processes. Here, we demonstrate analytically using the theory of Markov Chains and by numerical simulations in two classes of games, the Time-Horizon Minority Game [M.L. Hart, P. Jefferies, N.F. Johnson, Phys. A 311, 275 (2002)] and the Parrondo Game [J.M.R. Parrondo, G.P. Harmer, D. Abbott, Phys. Rev. Lett. 85, 5226 (2000); J.M.R. Parrondo, How to cheat a bad mathematician (ISI, Italy, 1996)], that agents who optimize their strategy based on past information may actually perform worse than non-optimizing agents. In other words, low-entropy (more informative) strategies under-perform high-entropy (or random) strategies. This provides a precise definition of the “illusion of control” in certain set-ups a priori defined to emphasize the importance of optimization.

  12. Space-time curvature and the cosmic horizon: derivations using the Newtonian world and the Friedmann-Robertson-Walker metric

    NASA Astrophysics Data System (ADS)

    Öztaş, A. M.; Smith, M. L.

    2015-05-01

    Several relationships describing the distance versus time dependence of the cosmic horizon (Rh) for an expanding universe have been published within the past two decades. Some are based on the special conditions, including a flat universe geometry, and when applied for calculation return significantly different values. We present our derivation beginning with Newtonian world then following the Friedmann model from the viewpoint of an observer located at the origin of an expanding spherical, homogeneously matter-dominated universe; both geometrically flat and allowing space-time curvature. Our derivations for the cosmic horizon at the speed of light allow examination for the effects of matter density and space-time curvature. We also compare the fitness of several current models, including the recently proposed Rh = ct universe against the demands of the 580 Union 2.1 Type Ia supernovae distance and redshift data with uncommon, proper attention paid to data transformation and observational errors.

  13. GOM Deepwater Horizon Oil Spill: A Time Series Analysis of Variations in Spilled Hydrocarbons

    NASA Astrophysics Data System (ADS)

    Palomo, C. M.; Yan, B.

    2013-12-01

    An estimated amount of 210 million gallons of crude oil was released into the Gulf of Mexico (GOM) from April 20th to July 15th 2010 during the Deepwater Horizon oil rig explosion. The spill caused a tremendous financial, ecological, environmental and health impact and continues to affect the GOM today. Variations in hydrocarbons including alkanes, hopanes and poly-cyclic aromatic hydrocarbons (PAHs) can be analyzed to better understand the oil spill and assist in oil source identification. Twenty-one sediment samples*, two tar ball samples and one surface water oil sample were obtained from distinct locations in the GOM and within varying time frames from May to December 2010. Each sample was extracted through the ASE 200 solvent extractor, concentrated down under nitrogen gas, purified through an alumina column, concentrated down again with nitrogen gas and analyzed via GC X GC-TOF MS. Forty-one different hydrocarbons were quantified in each sample. Various hydrocarbon 'fingerprints,' such as parental :alkylate PAH ratios, high molecular weight PAHs: low molecular weight alkane ratios, and carbon preference index were calculated. The initial objective of this project was to identify the relative hydrocarbon contributions of petrogenic sources and combustion sources. Based on the calculated ratios, it is evident that the sediment core taken in October of 2010 was greatly affected by combustion sources. Following the first month of the spill, oil in the gulf was burned in attempts to contain the spill. Combustion related sources have quicker sedimentation rates, and hydrocarbons from a combustion source essentially move into deeper depths quicker than those from a petrogenic source, as was observed in analyses of the October 2010 sediment. *Of the twenty-one sediment samples prepared, nine were quantified for this project.

  14. An experimental study of the influence of limited time horizon on positivity effects among young adults using eye-tracking.

    PubMed

    Cypryańska, Marzena; Krejtz, Izabela; Jaskółowska, Aleksandra; Kulawik, Alicja; Żukowska, Aleksandra; De Zavala, Agnieszka Golec; Niewiarowski, Jakub; Nezlek, John B

    2014-12-01

    Compared to younger adults, older adults attend more to positive stimuli, a positivity effect. Older adults have limited time horizons, and they focus on maintaining positive affect, whereas younger adults have unlimited time horizons, and they focus on acquiring knowledge and developing skills. Time horizons were manipulated by asking participants (66 young adults, M age = 20.5 yr., SD = 1.2) to think that their lives would end in three years. Some participants focused on what they would do in these three years (life focus), whereas others focused on the fact that they would die in three years (death focus). Attentional biases to facial expressions of happiness, sadness, fear, anger, and disgust were measured. Participants viewed 20 slides including pairings of a happy face with each of the negative emotions. The dependent measure was the relative attention paid to the faces on each slide. Participants in the experimental conditions exhibited a positivity effect compared to participants in the control condition, although some results suggested that this effect was weaker in the death focus condition than in the life focus condition. PMID:25457091

  15. Optimal stock liquidation in a regime switching model with finite time horizon

    NASA Astrophysics Data System (ADS)

    Pemy, M.; Zhang, Q.

    2006-09-01

    This paper is concerned with a finite-horizon optimal selling rule. A set of geometric Brownian motions coupled by a finite-state Markov chain is used to characterize stock price movements. Given a fixed transaction fee, the optimal selling rule can be obtained by solving an optimal stopping problem. The corresponding value function is shown to be the unique viscosity solution to the associated HJB equations. Numerical solutions to these equations and their convergence are obtained. A numerical example is presented to illustrate the results.

  16. 41 CFR 302-2.10 - Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 4 2014-07-01 2014-07-01 false Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my household effects due to... time that I cannot travel and/or transport my household effects due to shipping restrictions to or...

  17. 41 CFR 302-2.10 - Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my household effects due to... time that I cannot travel and/or transport my household effects due to shipping restrictions to or...

  18. Emergence of time-horizon invariant correlation structure in financial returns by subtraction of the market mode

    NASA Astrophysics Data System (ADS)

    Borghesi, Christian; Marsili, Matteo; Miccichè, Salvatore

    2007-08-01

    We investigate the emergence of a structure in the correlation matrix of assets’ returns as the time horizon over which returns are computed increases from the minutes to the daily scale. We analyze data from different stock markets (New York, Paris, London, Milano) and with different methods. In addition to the usual correlations, we also analyze those obtained by subtracting the dynamics of the “center of mass” (i.e., the market mode). We find that when the center of mass is not removed the structure emerges, as the time horizon increases, from splitting a single large cluster into smaller ones. By contrast, when the market mode is removed the structure of correlations observed at the daily scale is already well defined at very high frequency ( 5min in the New York Stock Exchange). Moreover, this structure accounts for 80% of the classification of stocks in economic sectors. Similar results, though less sharp, are found for the other markets. We also find that the structure of correlations in the overnight returns is markedly different from that of intraday activity.

  19. Time-lapse borehole radar for monitoring rainfall infiltration through podosol horizons in a sandy vadose zone

    NASA Astrophysics Data System (ADS)

    Strobach, Elmar; Harris, B. D.; Dupuis, J. C.; Kepic, A. W.

    2014-03-01

    The shallow aquifer on the Gnangara Mound, north of Perth, Western Australia, is recharged by winter rainfall. Water infiltrates through a sandy Podosol where cemented accumulation (B-) horizons are common. They are water retentive and may impede recharge. To observe wetting fronts and the influence of soil horizons on unsaturated flow, we deployed time-lapse borehole radar techniques sensitive to soil moisture variations during an annual recharge cycle. Zero-offset crosswell profiling (ZOP) and vertical radar profiling (VRP) measurements were performed at six sites on a monthly basis before, during, and after annual rainfall in 2011. Water content profiles are derived from ZOP logs acquired in closely spaced wells. Sites with small separation between wells present potential repeatability and accuracy difficulties. Such problems could be lessened by (i) ZOP saturated zone velocity matching of time-lapse curves, and (ii) matching of ZOP and VRP results. The moisture contents for the baseline condition and subsequent observations are computed using the Topp relationship. Time-lapse moisture curves reveal characteristic vadose zone infiltration regimes. Examples are (I) full recharge potential after 200 mm rainfall, (II) delayed wetting and impeded recharge, and (III) no recharge below 7 m depth. Seasonal infiltration trends derived from long-term time-lapse neutron logging at several sites are shown to be comparable with infiltration trends recovered from time-lapse crosswell radar measurements. However, radar measurements sample a larger volume of earth while being safer to deploy than the neutron method which employs a radioactive source. For the regime (III) site, where time-lapse radar indicates no net recharge or zero flux to the water table, a simple water balance provides an evapotranspiration value of 620 mm for the study period. This value compares favorably to previous studies at similar test sites in the region. Our six field examples demonstrate

  20. The State of Pluto's Bulk Atmosphere at the Time of the New Horizons Encounter

    NASA Astrophysics Data System (ADS)

    Resnick, Aaron C.; Barry, T.; Buie, M. W.; Carriazo, C. Y.; Cole, A.; Gault, D.; Giles, B.; Giles, D.; Hartig, K.; Hill, K.; Howell, R. R.; Hudson, G.; Loader, B.; Mackie, J.; Nelson, M.; Olkin, C.; Register, J.; Rodgers, T.; Sicardy, B.; Skrutskie, M.; Verbiscer, A.; Wasserman, L.; Watson, C.; Young, E.; Young, L.; Zalucha, A.

    2015-11-01

    On 29-JUL-2015, our team - plus many critical amateur astronomers - observed a stellar occultation by Pluto from sites in Australia and New Zealand. This event was remarkable for two reasons: it preceded the New Horizons flyby of Pluto by just two weeks, and the occulted star was about 10x brighter than Pluto itself, by far the brightest Pluto occultation event observed to date. The separation of ground sites spanned nearly 900 km with respect to the central chord, allowing a good geometric solution for the shadow path. The lightcurves show some inflection points and broad "fangs" that are characteristic of perturbations in the temperature profile. Preliminary fits show that the temperature profile derived from a 2006 occultation (Young et al. 2008) reproduces the 29-JUN-2015 lightcurves well. Assuming a surface radius of 1187 km for Pluto, we find that the surface pressure is 18 +/- 3 µbar. This pressure indicates that Pluto's surface has not yet started to cool down, despite a decrease in absorbed solar flux of more than 17% since perihelion in 1988. A surface pressure of 18 µbar would correspond to a nitrogen ice surface temperature of 38.0 K.References:Young, E.F., et al. "Vertical Structure in Pluto's Atmosphere from the 2006 June 12 Stellar Occultation," AJ 136 1757-1769 (2008)

  1. Water Stress on U.S. Power Production at Decadal Time Horizons

    NASA Astrophysics Data System (ADS)

    Ganguli, P.; Kumar, D.; Yun, J.; Short, G.; Klausner, J.; Ganguly, A. R.

    2014-12-01

    Thermoelectric power production at risk, owing to current and projected water scarcity and rising stream temperatures, is assessed for the continental United States (US) at decadal scales. Regional water scarcity is driven by climate variability and change, as well as by multi-sector water demand. While a planning horizon of zero to about thirty years is occasionally prescribed by stakeholders, the challenges to risk assessment at these scales include the difficulty in delineating decadal climate trends from intrinsic natural or multiple model variability. Current generation global climate or earth system models are not credible at the spatial resolutions of power plants, especially for surface water quantity and stream temperatures, which further exacerbates the assessment challenge. Population changes, which are anyway difficult to project, cannot serve as adequate proxies for changes in the water demand across sectors. The hypothesis that robust assessments of power production at risks are possible, despite the uncertainties, has been examined as a proof of concept. An approach is presented for delineating water scarcity and temperature from climate models, observations and population storylines, as well as for assessing power production at risk by examining geospatial correlations of power plant locations within regions where the usable water supply for energy production happens to be scarcer and warmer. Acknowledgment: Funding provided by US DOE's ARPA-E through Award DE-AR0000374.

  2. 41 CFR 302-2.10 - Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 4 2013-07-01 2012-07-01 true Does the 1-year time period in § 302-2.8 include time that I cannot travel and/or transport my household effects due to shipping restrictions to or from my post of duty OCONUS? 302-2.10 Section 302-2.10 Public Contracts and Property Management Federal Travel...

  3. Adaptive dynamic programming for finite-horizon optimal control of discrete-time nonlinear systems with ε-error bound.

    PubMed

    Wang, Fei-Yue; Jin, Ning; Liu, Derong; Wei, Qinglai

    2011-01-01

    In this paper, we study the finite-horizon optimal control problem for discrete-time nonlinear systems using the adaptive dynamic programming (ADP) approach. The idea is to use an iterative ADP algorithm to obtain the optimal control law which makes the performance index function close to the greatest lower bound of all performance indices within an ε-error bound. The optimal number of control steps can also be obtained by the proposed ADP algorithms. A convergence analysis of the proposed ADP algorithms in terms of performance index function and control policy is made. In order to facilitate the implementation of the iterative ADP algorithms, neural networks are used for approximating the performance index function, computing the optimal control policy, and modeling the nonlinear system. Finally, two simulation examples are employed to illustrate the applicability of the proposed method. PMID:20876014

  4. Neural network-based finite-horizon optimal control of uncertain affine nonlinear discrete-time systems.

    PubMed

    Zhao, Qiming; Xu, Hao; Jagannathan, Sarangapani

    2015-03-01

    In this paper, the finite-horizon optimal control design for nonlinear discrete-time systems in affine form is presented. In contrast with the traditional approximate dynamic programming methodology, which requires at least partial knowledge of the system dynamics, in this paper, the complete system dynamics are relaxed utilizing a neural network (NN)-based identifier to learn the control coefficient matrix. The identifier is then used together with the actor-critic-based scheme to learn the time-varying solution, referred to as the value function, of the Hamilton-Jacobi-Bellman (HJB) equation in an online and forward-in-time manner. Since the solution of HJB is time-varying, NNs with constant weights and time-varying activation functions are considered. To properly satisfy the terminal constraint, an additional error term is incorporated in the novel update law such that the terminal constraint error is also minimized over time. Policy and/or value iterations are not needed and the NN weights are updated once a sampling instant. The uniform ultimate boundedness of the closed-loop system is verified by standard Lyapunov stability theory under nonautonomous analysis. Numerical examples are provided to illustrate the effectiveness of the proposed method. PMID:25720005

  5. Time horizons and substance use among African American youths living in disadvantaged urban areas.

    PubMed

    Cheong, JeeWon; Tucker, Jalie A; Simpson, Cathy A; Chandler, Susan D

    2014-04-01

    Transitioning from adolescence to full-fledged adulthood is often challenging, and young people who live in disadvantaged urban neighborhoods face additional obstacles and experience disproportionately higher negative outcomes, including substance abuse and related risk behaviors. This study investigated whether substance use among African Americans ages 15 to 25 (M=18.86 years) living in such areas was related to present-dominated time perspectives and higher delay discounting. Participants (N=344, 110 males, 234 females) living in Deep South disadvantaged urban neighborhoods were recruited using Respondent Driven Sampling, an improved peer-referral sampling method suitable for accessing this hard-to-reach target group. Structured field interviews assessed alcohol, tobacco, and illicit drug use and risk/protective factors, including time perspectives (Zimbardo Time Perspective Inventory [ZTPI]) and behavioral impulsivity (delay discounting task). As predicted, substance use was positively related to a greater ZTPI orientation toward present pleasure and a lower tendency to plan and achieve future goals. Although the sample as a whole showed high discounting of delayed rewards, discount rates did not predict substance use. The findings suggest that interventions to lengthen time perspectives and promote enriched views of future possible selves may prevent and reduce substance use among disadvantaged youths. Discontinuities among the discounting and time perspective variables in relation to substance use merit further investigation. PMID:24531637

  6. Impact of curvature divergences on physical observers in a wormhole space-time with horizons

    NASA Astrophysics Data System (ADS)

    Olmo, Gonzalo J.; Rubiera-Garcia, D.; Sanchez-Puente, A.

    2016-06-01

    The impact of curvature divergences on physical observers in a black hole space-time, which, nonetheless, is geodesically complete is investigated. This space-time is an exact solution of certain extensions of general relativity coupled to Maxwell’s electrodynamics and, roughly speaking, consists of two Reissner-Nordström (or Schwarzschild or Minkowski) geometries connected by a spherical wormhole near the center. We find that, despite the existence of infinite tidal forces, causal contact is never lost among the elements making up the observer. This suggests that curvature divergences may not be as pathological as traditionally thought.

  7. 1.3 mm WAVELENGTH VLBI OF SAGITTARIUS A*: DETECTION OF TIME-VARIABLE EMISSION ON EVENT HORIZON SCALES

    SciTech Connect

    Fish, Vincent L.; Doeleman, Sheperd S.; Beaudoin, Christopher; Bolin, David E.; Rogers, Alan E. E.; Blundell, Ray; Gurwell, Mark A.; Moran, James M.; Primiani, Rurik; Bower, Geoffrey C.; Plambeck, Richard; Chamberlin, Richard; Freund, Robert; Friberg, Per; Honma, Mareki; Oyama, Tomoaki; Inoue, Makoto; Krichbaum, Thomas P.; Lamb, James; Marrone, Daniel P.

    2011-02-01

    Sagittarius A*, the {approx}4 x 10{sup 6} M{sub sun} black hole candidate at the Galactic center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength very long baseline interferometry (VLBI). We report on 1.3 mm wavelength observations of Sgr A* using a VLBI array consisting of the JCMT on Mauna Kea, the Arizona Radio Observatory's Submillimeter Telescope on Mt. Graham in Arizona, and two telescopes of the CARMA array at Cedar Flat in California. Both Sgr A* and the quasar calibrator 1924-292 were observed over three consecutive nights, and both sources were clearly detected on all baselines. For the first time, we are able to extract 1.3 mm VLBI interferometer phase information on Sgr A* through measurement of closure phase on the triangle of baselines. On the third night of observing, the correlated flux density of Sgr A* on all VLBI baselines increased relative to the first two nights, providing strong evidence for time-variable change on scales of a few Schwarzschild radii. These results suggest that future VLBI observations with greater sensitivity and additional baselines will play a valuable role in determining the structure of emission near the event horizon of Sgr A*.

  8. Killing Horizons Kill Horizon Degrees

    NASA Astrophysics Data System (ADS)

    Bergamin, L.; Grumiller, D.

    Frequently, it is argued that the microstates responsible for the Bekenstein-Hawking entropy should arise from some physical degrees of freedom located near or on the black hole horizon. In this essay, we elucidate that instead entropy may emerge from the conversion of physical degrees of freedom, attached to a generic boundary, into unobservable gauge degrees of freedom attached to the horizon. By constructing the reduced phase space, it can be demonstrated that such a transmutation indeed takes place for a large class of black holes, including Schwarzschild.

  9. The Glacier Peak Tephra: A Continental-Scale Latest Pleistocene Time Horizon

    NASA Astrophysics Data System (ADS)

    Pyne-O'Donnell, S.; Cwynar, L. C.; Vincent, J. H.; Spear, R.; Froese, D. G.

    2014-12-01

    The latest Pleistocene eruptions of Glacier Peak in the Cascade Range deposited a widespread set of tephras throughout much of western North America within a short time span where they serve as valuable marker layers for inter-site correlation and chronostratigraphical control. We report the detection of these tephras in microscopic form in three lakes along the Eastern Seaboard (Maine and Nova Scotia). These distinct distal lake layers occur as closely spaced couplets which retain the subtle geochemical variation that characterises the proximal Glacier Peak G and B layers. New radiocarbon dates for the tephras also closely corroborate the most recently revised proximal dates for the tephras (ca. 13,700 - 13,400 cal. yr B.P) which found that they are ca. 400 14C yr older than hitherto thought. Their presence this far eastward implies that their deposition spans the intervening continent (>4000 km) and adds to a developing distal tephrostratigraphical framework with applications to studies of latest Pleistocene deglaciation and environmental change, megafaunal extinction and archaeology.

  10. HORIZON SENSING (PROPOSAL NO.51)

    SciTech Connect

    Larry G. Stolarczyk

    2003-07-01

    Real-time horizon sensing on continuous mining machines is becoming an industry tool. Installation and testing of production-grade Horizon Sensor (HS) systems continued this quarter at Monterey Coal Company (ExxonMobil), Mountain Coal Company West Elk Mine (Arch), and Ohio Valley Coal Company (OVC). Monitoring of system function, user experience, and mining benefits is ongoing. All horizon sensor components have finished MSHA (U.S.) and IEC (International) certification.

  11. HORIZON SENSING (PROPOSAL NO.51)

    SciTech Connect

    Larry G. Stolarczyk

    2003-07-30

    Real-time horizon sensing on continuous mining (CM) machines is becoming an industry tool. Installation and testing of production-grade Horizon Sensor (HS) systems has been ongoing this quarter at Monterey Coal Company (ExxonMobil), Mountain Coal Company West Elk Mine (Arch), Deserado Mining Company (Blue Mountain Energy), and The Ohio Valley Coal Company (TOVCC). Monitoring of system function, user experience, and mining benefits is ongoing. All horizon sensor components have finished MSHA (U.S.) and IEC (International) certification.

  12. The optimal manufacturing batch size with rework under time-varying demand process for a finite time horizon

    NASA Astrophysics Data System (ADS)

    Musa, Sarah; Supadi, Siti Suzlin; Omar, Mohd

    2014-07-01

    Rework is one of the solutions to some of the main issues in reverse logistic and green supply chain as it reduces production cost and environmental problem. Many researchers focus on developing rework model, but to the knowledge of the author, none of them has developed a model for time-varying demand rate. In this paper, we extend previous works and develop multiple batch production system for time-varying demand rate with rework. In this model, the rework is done within the same production cycle.

  13. Planning ahead in public health? A qualitative study of the time horizons used in public health decision-making

    PubMed Central

    Taylor-Robinson, David C; Milton, Beth; Lloyd-Williams, Ffion; O'Flaherty, Martin; Capewell, Simon

    2008-01-01

    Background In order to better understand factors that influence decisions for public health, we undertook a qualitative study to explore issues relating to the time horizons used in decision-making. Methods Qualitative study using semi-structured interviews. 33 individuals involved in the decision making process around coronary heart disease were purposively sampled from the UK National Health Service (national, regional and local levels), academia and voluntary organizations. Analysis was based on the framework method using N-VIVO software. Interviews were transcribed, coded and emergent themes identified. Results Many participants suggested that the timescales for public health decision-making are too short. Commissioners and some practitioners working at the national level particularly felt constrained in terms of planning for the long-term. Furthermore respondents felt that longer term planning was needed to address the wider determinants of health and to achieve societal level changes. Three prominent 'systems' issues were identified as important drivers of short term thinking: the need to demonstrate impact within the 4 year political cycle; the requirement to 'balance the books' within the annual commissioning cycle and the disruption caused by frequent re-organisations within the health service. In addition respondents suggested that the tools and evidence base for longer term planning were not well established. Conclusion Many public health decision and policy makers feel that the timescales for decision-making are too short. Substantial systemic barriers to longer-term planning exist. Policy makers need to look beyond short-term targets and budget cycles to secure investment for long-term improvement in public health. PMID:19094194

  14. A Time-Series of Surface Oil Distribution Detected by Satellite SAR During the Deepwater Horizon Blowout

    NASA Astrophysics Data System (ADS)

    MacDonald, I. R.; Garcia-Pineda, O. G.; Solow, A.; Daneshgar, S.; Beet, A.

    2013-12-01

    Oil discharged as a result of the Deepwater Horizon disaster was detected on the surface of the Gulf of Mexico by synthetic aperture radar satellites from 25 April 2010 until 4 August 2010. SAR images were not restricted by daylight or cloud-cover. Distribution of this material is a tracer for potential environmental impacts and an indicator of impact mitigation due to response efforts and physical forcing factors. We used a texture classifying neural network algorithm for semi-supervised processing of 176 SAR images from the ENVISAT, RADARSAT I, and COSMO-SKYMED satellites. This yielded an estimate the proportion of oil-covered water within the region sampled by each image with a nominal resolution of 10,000 sq m (100m pixels), which was compiled as a 5-km equal area grid covering the northern Gulf of Mexico. Few images covered the entire impact area, so analysis was required to compile a regular time-series of the oil cover. A Gaussian kernel using a bandwidth of 2 d was used to estimate oil cover percent in each grid at noon and midnight throughout the interval. Variance and confidence intervals were calculated for each grid and for the global 12-h totals. Results animated across the impact region show the spread of oil under the influence of physical factors. Oil cover reached an early peak of 17032.26 sq km (sd 460.077) on 18 May, decreasing to 27% of this total on 4 June, following by sharp increase to an overall maximum of 18424.56 sq km (sd 424.726) on 19 June. There was a significant negative correlation between average wind stress and the total area of oil cover throughout the time-series. Correlation between response efforts including aerial and subsurface application of dispersants and burning of gathered oil was negative, positive, or indeterminate at different time segments during the event. Daily totals for oil-covered surface waters of the Gulf of Mexico during 25 April - 9 August 2010 with upper and lower 0.95 confidence limits on estimate. (No oil

  15. Emotional Development: 1 Year Olds

    MedlinePlus

    ... Español Text Size Email Print Share Emotional Development: 1 Year Olds Page Content Article Body Throughout her ... for shelter. She may seem to change from one moment to the next, or she may seem ...

  16. Social Development: 1 Year Olds

    MedlinePlus

    ... Stages Prenatal Baby Toddler Fitness Nutrition Toilet Training Preschool Gradeschool Teen Young Adult Healthy Children > Ages & Stages > Toddler > Social Development: 1 Year Olds Ages & Stages Listen Español ...

  17. The relationship between low back pain and leisure time physical activity in a working population of cleaners - a study with weekly follow-ups for 1 year

    PubMed Central

    2012-01-01

    Background Low back pain (LBP) and leisure time physical activity (LTPA) are considered to be closely related, and clinical guidelines for the treatment of acute LBP recommend patients stay physically active. However, the documentation for this recommendation is sparse and based on studies involving patient populations. The purpose of the study was (1) to investigate the correlation between LBP and LTPA on a weekly basis over the course of a year in a high-risk group of cleaners; and (2) to investigate if maintaining LTPA during an episode of acute LBP has a positive effect on LBP intensity in the subsequent 4 weeks. Methods 188 cleaners consented to participate in a 52-week text message survey about hours of LTPA and intensity of LBP (from 0 to 9) over the previous 7 days. The correlation between LBP and LTPA was calculated by Pearson correlation coefficient. During an episode of acute LBP, a mixed effect logistic regression model was used to investigate whether cleaners who maintain LTPA have a lower pain intensity and higher probability of returning to initial pain intensity within the following four weeks compared with cleaners who decrease LTPA during acute LBP. Results The correlation between weekly LTPA and LBP data was negative, but numerically low (r = -0.069) and statistically insignificant (p = 0.08). Among the 82 cleaners experiencing at least one episode of acute LBP, those maintaining LTPA during an episode of acute LBP did not have a lower pain intensity (average LBP intensity difference between groups of 0.06; 95% confidence interval (95% CI) of -0.417 to 0.539) or higher probability of returning to initial pain level (Odds ratio 1,02; 95% CI of 0.50 to 2.09) in the following four weeks compared with cleaners decreasing LTPA during acute LBP. Conclusions Hours of LTPA and intensity of LBP measured on a weekly basis throughout a year showed no close correlation. Maintaining LTPA during an episode of acute LBP did not result in a positive effect on

  18. Refraction near the horizon

    NASA Technical Reports Server (NTRS)

    Schaefer, Bradley E.; Liller, William

    1990-01-01

    Variations in astronomical refraction near the horizon are examined. Sunset timings, a sextant mounted on a tripod, and a temperature profile are utilized to derive the variations in refraction data, collected from 7 locations. It is determined that the refraction ranges from 0.234 to 1.678 deg with an rms deviation of 0.16, and it is observed that the variation is larger than previously supposed. Some applications for the variation of refraction value are discussed.

  19. HORIZON SENSING (PROPOSAL No.51)

    SciTech Connect

    Larry G. Stolarczyk, Sc.D.

    2002-04-30

    Real-time horizon sensing on continuous mining machines is becoming an industry tool. Installation and testing of production-grade HS systems has been ongoing this quarter at Monterey Coal Company (EXXON), FMC Trona, Twentymile Coal Company (RAG America), and SASOL Coal. Detailed monitoring of system function, user experience, and mining benefits is ongoing. All horizon sensor components have finished MSHA (U.S.) and IEC (International) certification.

  20. South american geochronology: radiometric time scale for middle to late tertiary mammal-bearing horizons in patagonia.

    PubMed

    Marshall, L G; Pascual, R; Curtis, G H; Drake, R E

    1977-03-25

    Radiometric (potassium-argon) age determinations for basalts and tuffs associated with middle to late Tertiary mammal-bearing horizons in Patagonia, southern Argentina, permit refinement of boundaries and hiatuses between beds of Deseadan (early Oligocene) through Friasian (middle to late Miocene) age. At two localities beds of Deseadan age are overlain by basalts, which gave dates of 33.6 and 35.4 million years ago; 34.0 million years ago is tentatively accepted as a terminal date for known Deseadan. At several localities beds of Colhuehuapian age are underlain by basalts, which gave dates ranging from 28.8 to 24.3 million years ago; 25.0 million years is tentatively taken as a basal age for known Colhuehuapian. The paleontological hiatus between known Deseadan and known Colhuehuapian is thus in the order of 9.0 million years. Two tuffs from the Santa Cruz Formation (Santacrucian) gave ages of 21.7 and 18.5 million years. Plagioclase and biotite concentrates of an ignimbrite from the Collón Curá Formation (Friasian) gave ages ranging from 15.4 to 14.0 million years. PMID:17738414

  1. Pluto's Atmosphere from the 2015 June 29 Ground-based Stellar Occultation at the Time of the New Horizons Flyby

    NASA Astrophysics Data System (ADS)

    Sicardy, B.; Talbot, J.; Meza, E.; Camargo, J. I. B.; Desmars, J.; Gault, D.; Herald, D.; Kerr, S.; Pavlov, H.; Braga-Ribas, F.; Assafin, M.; Benedetti-Rossi, G.; Dias-Oliveira, A.; Gomes-Júnior, A. R.; Vieira-Martins, R.; Bérard, D.; Kervella, P.; Lecacheux, J.; Lellouch, E.; Beisker, W.; Dunham, D.; Jelínek, M.; Duffard, R.; Ortiz, J. L.; Castro-Tirado, A. J.; Cunniffe, R.; Querel, R.; Yock, P. C.; Cole, A. A.; Giles, A. B.; Hill, K. M.; Beaulieu, J. P.; Harnisch, M.; Jansen, R.; Pennell, A.; Todd, S.; Allen, W. H.; Graham, P. B.; Loader, B.; McKay, G.; Milner, J.; Parker, S.; Barry, M. A.; Bradshaw, J.; Broughton, J.; Davis, L.; Devillepoix, H.; Drummond, J.; Field, L.; Forbes, M.; Giles, D.; Glassey, R.; Groom, R.; Hooper, D.; Horvat, R.; Hudson, G.; Idaczyk, R.; Jenke, D.; Lade, B.; Newman, J.; Nosworthy, P.; Purcell, P.; Skilton, P. F.; Streamer, M.; Unwin, M.; Watanabe, H.; White, G. L.; Watson, D.

    2016-03-01

    We present results from a multi-chord Pluto stellar occultation observed on 2015 June 29 from New Zealand and Australia. This occurred only two weeks before the NASA New Horizons flyby of the Pluto system and serves as a useful comparison between ground-based and space results. We find that Pluto's atmosphere is still expanding, with a significant pressure increase of 5 ± 2% since 2013 and a factor of almost three since 1988. This trend rules out, as of today, an atmospheric collapse associated with Pluto's recession from the Sun. A central flash, a rare occurrence, was observed from several sites in New Zealand. The flash shape and amplitude are compatible with a spherical and transparent atmospheric layer of roughly 3 km in thickness whose base lies at about 4 km above Pluto's surface, and where an average thermal gradient of about 5 K km-1 prevails. We discuss the possibility that small departures between the observed and modeled flash are caused by local topographic features (mountains) along Pluto's limb that block the stellar light. Finally, using two possible temperature profiles, and extrapolating our pressure profile from our deepest accessible level down to the surface, we obtain a possible range of 11.9-13.7 μbar for the surface pressure. Partly based on observations made with the ESO WFI camera at the 2.2 m Telescope (La Silla), under program ID 079.A-9202(A) within the agreement between the ON/MCTI and the Max Planck Society, with the ESO camera NACO at the Very Large Telescope (Paranal), under program ID 089.C-0314(C), and at the Pico dos Dias Observatory/LNA, Brazil.

  2. Gravitational Horizon(3)

    NASA Astrophysics Data System (ADS)

    Yang, Chao Yuan

    2012-05-01

    Anomalous decelerations of spacecraft Pioneer-10,11,etc could be interpreted as signal delay effect between speed of gravity and that of light as reflected in virtual scale, similar to covarying virtual scale effect in relative motion (http://arxiv.org/html/math-ph/0001019v5).A finite speed of gravity faster than light could be inferred (http://arXiv.org/html/physics/0001034v2). Measurements of gravitational variations by paraconical pendulum during a total solar eclipse infer the same(http://arXiv.org/html/physics/0001034v9). A finite Superluminal speed of gravity is the necessary condition to imply that there exists gravitational horizon (GH). Such "GH" of our Universe would stretch far beyond the cosmic event horizon of light. Dark energy may be owing to mutually interactive gravitational horizons of cousin universes. Sufficient condition for the conjecture is that the dark energy would be increasing with age of our Universe since accelerated expansion started about 5 Gyr ago, since more and more arrivals of "GH" of distant cousin universes would interact with "GH" of our Universe. The history of dark energy variations between then and now would be desirable(http://arXiv.org/html/physics/0001034). In "GH" conjecture, the neighborhood of cousin universes would be likely boundless in 4D-space-time without begining or end. The dark energy would keep all universes in continually accelerated expansion to eventual fragmentation. Fragments would crash and merge into bangs, big or small, to form another generation of cousin universes. These scenarios might offer a clue to what was before the big bang.

  3. Finite-Horizon Near-Optimal Output Feedback Neural Network Control of Quantized Nonlinear Discrete-Time Systems With Input Constraint.

    PubMed

    Xu, Hao; Zhao, Qiming; Jagannathan, Sarangapani

    2015-08-01

    The output feedback-based near-optimal regulation of uncertain and quantized nonlinear discrete-time systems in affine form with control constraint over finite horizon is addressed in this paper. First, the effect of input constraint is handled using a nonquadratic cost functional. Next, a neural network (NN)-based Luenberger observer is proposed to reconstruct both the system states and the control coefficient matrix so that a separate identifier is not needed. Then, approximate dynamic programming-based actor-critic framework is utilized to approximate the time-varying solution of the Hamilton-Jacobi-Bellman using NNs with constant weights and time-dependent activation functions. A new error term is defined and incorporated in the NN update law so that the terminal constraint error is also minimized over time. Finally, a novel dynamic quantizer for the control inputs with adaptive step size is designed to eliminate the quantization error overtime, thus overcoming the drawback of the traditional uniform quantizer. The proposed scheme functions in a forward-in-time manner without offline training phase. Lyapunov analysis is used to investigate the stability. Simulation results are given to show the effectiveness and feasibility of the proposed method. PMID:25794403

  4. Deepwater Horizon Situation Report #5

    SciTech Connect

    2010-06-10

    At approximately 11:00 pm EDT April 20, 2010 an explosion occurred aboard the Deepwater Horizon mobile offshore drilling unit (MODU) located 52 miles Southeast of Venice, LA and 130 miles southeast of New Orleans, LA. The MODU was drilling an exploratory well and was not producing oil at the time of the incident. The Deepwater Horizon MODU sank 1,500 feet northwest of the well site. Detailed information on response and recovery operations can be found at: http://www.deepwaterhorizonresponse.com/go/site/2931/

  5. Horizon Report: 2009 Economic Development Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Levine, A.; Scott, C.; Smith, R.; Stone, S.

    2009-01-01

    The New Media Consortium's Horizon Project is an ongoing research project that seeks to identify and describe emerging technologies likely to have a large impact in education and other industries around the world over a five-year time period. The chief products of the project are the "Horizon Reports", an annual series of publications that…

  6. Does time heal all wounds? Community attachment, natural resource employment, and health impacts in the wake of the BP Deepwater Horizon disaster.

    PubMed

    Cope, Michael R; Slack, Tim; Blanchard, Troy C; Lee, Matthew R

    2013-05-01

    On April 20, 2010, the BP-leased Deepwater Horizon (BP-DH) oil rig exploded, resulting in the largest marine oil spill in history. In this paper we utilize one-of-a-kind household survey data-the Louisiana Community Oil Spill Survey-to examine the impacts of the BP-DH disaster on the mental and physical health of spill affected residents in coastal Louisiana, with a special focus on the influence of community attachment and natural resource employment. We find that levels of both negative mental and physical health were significantly more pronounced at baseline compared to later time points. We show that greater community attachment is linked to lower levels of negative health impacts in the wake of the oil spill and that the disaster had a uniquely negative impact on households involved in the fishing industry. Further, we find evidence that the relationship between community attachment and mental health is more pronounced at later points in time, and that the negative health impacts on fishers have worsened over time. Implications for research and policy are discussed. PMID:23522000

  7. The New Horizons Spacecraft

    NASA Astrophysics Data System (ADS)

    Fountain, Glen H.; Kusnierkiewicz, David Y.; Hersman, Christopher B.; Herder, Timothy S.; Coughlin, Thomas B.; Gibson, William C.; Clancy, Deborah A.; Deboy, Christopher C.; Hill, T. Adrian; Kinnison, James D.; Mehoke, Douglas S.; Ottman, Geffrey K.; Rogers, Gabe D.; Stern, S. Alan; Stratton, James M.; Vernon, Steven R.; Williams, Stephen P.

    2008-10-01

    The New Horizons spacecraft was launched on 19 January 2006. The spacecraft was designed to provide a platform for seven instruments designated by the science team to collect and return data from Pluto in 2015. The design meets the requirements established by the National Aeronautics and Space Administration (NASA) Announcement of Opportunity AO-OSS-01. The design drew on heritage from previous missions developed at The Johns Hopkins University Applied Physics Laboratory (APL) and other missions such as Ulysses. The trajectory design imposed constraints on mass and structural strength to meet the high launch acceleration consistent with meeting the AO requirement of returning data prior to the year 2020. The spacecraft subsystems were designed to meet tight resource allocations (mass and power) yet provide the necessary control and data handling finesse to support data collection and return when the one-way light time during the Pluto fly-by is 4.5 hours. Missions to the outer regions of the solar system (where the solar irradiance is 1/1000 of the level near the Earth) require a radioisotope thermoelectric generator (RTG) to supply electrical power. One RTG was available for use by New Horizons. To accommodate this constraint, the spacecraft electronics were designed to operate on approximately 200 W. The travel time to Pluto put additional demands on system reliability. Only after a flight time of approximately 10 years would the desired data be collected and returned to Earth. This represents the longest flight duration prior to the return of primary science data for any mission by NASA. The spacecraft system architecture provides sufficient redundancy to meet this requirement with a probability of mission success of greater than 0.85. The spacecraft is now on its way to Pluto, with an arrival date of 14 July 2015. Initial in-flight tests have verified that the spacecraft will meet the design requirements.

  8. Time- and Oil-Dependent Transcriptomic and Physiological Responses to Deepwater Horizon Oil in Mahi-Mahi (Coryphaena hippurus) Embryos and Larvae.

    PubMed

    Xu, Elvis Genbo; Mager, Edward M; Grosell, Martin; Pasparakis, Christina; Schlenker, Lela S; Stieglitz, John D; Benetti, Daniel; Hazard, E Starr; Courtney, Sean M; Diamante, Graciel; Freitas, Juliane; Hardiman, Gary; Schlenk, Daniel

    2016-07-19

    The Deepwater Horizon (DWH) oil spill contaminated the spawning habitats for numerous commercially and ecologically important fishes. Exposure to the water accommodated fraction (WAF) of oil from the spill has been shown to cause cardiac toxicity during early developmental stages across fishes. To better understand the molecular events and explore new pathways responsible for toxicity, RNA sequencing was performed in conjunction with physiological and morphological assessments to analyze the time-course (24, 48, and 96 h post fertilization (hpf)) of transcriptional and developmental responses in embryos/larvae of mahi-mahi exposed to WAF of weathered (slick) and source DWH oils. Slick oil exposure induced more pronounced changes in gene expression over time than source oil exposure. Predominant transcriptomic responses included alteration of EIF2 signaling, steroid biosynthesis, ribosome biogenesis and activation of the cytochrome P450 pathway. At 96 hpf, slick oil exposure resulted in significant perturbations in eye development and peripheral nervous system, suggesting novel targets in addition to the heart may be involved in the developmental toxicity of DHW oil. Comparisons of changes of cardiac genes with phenotypic responses were consistent with reduced heart rate and increased pericardial edema in larvae exposed to slick oil but not source oil. PMID:27348429

  9. Semiclassical ultraextremal horizons

    SciTech Connect

    Matyjasek, Jerzy; Zaslavskii, O.B.

    2005-04-15

    We examine backreaction of quantum massive fields on multiply-degenerate (ultraextremal) horizons. It is shown that, under influence of the quantum backreaction, the horizon of such a kind moves to a new position near which the metric does not change its asymptotics, so the ultraextremal black holes and cosmological spacetimes do exist as self-consistent solutions of the semiclassical field equations.

  10. The 2011 Horizon Report

    ERIC Educational Resources Information Center

    Johnson, L.; Smith, R.; Willis, H.; Levine, A.; Haywood, K.

    2011-01-01

    The internationally recognized series of "Horizon Reports" is part of the New Media Consortium's Horizon Project, a comprehensive research venture established in 2002 that identifies and describes emerging technologies likely to have a large impact over the coming five years on a variety of sectors around the globe. This volume, the "2011 Horizon…

  11. Two Horizons of Fusion

    ERIC Educational Resources Information Center

    Lo, Mun Ling; Chik, Pakey Pui Man

    2016-01-01

    In this paper, we aim to differentiate the internal and external horizons of "fusion." "Fusion" in the internal horizon relates to the structure and meaning of the object of learning as experienced by the learner. It clarifies the interrelationships among an object's critical features and aspects. It also illuminates the…

  12. The 2010 Horizon Report

    ERIC Educational Resources Information Center

    Johnson, L.; Levine, A.; Smith, R.; Stone, S.

    2010-01-01

    The annual "Horizon Report" describes the continuing work of the New Media Consortium's Horizon Project, a qualitative research project established in 2002 that identifies and describes emerging technologies likely to have a large impact on teaching, learning, or creative inquiry on college and university campuses within the next five years. The…

  13. Fuzziness at the horizon

    NASA Astrophysics Data System (ADS)

    Batic, Davide; Nicolini, Piero

    2010-08-01

    We study the stability of the noncommutative Schwarzschild black hole interior by analysing the propagation of a massless scalar field between the two horizons. We show that the spacetime fuzziness triggered by the field higher momenta can cure the classical exponential blue-shift divergence, suppressing the emergence of infinite energy density in a region nearby the Cauchy horizon.

  14. Geochemical and isotopic time series of oil deposited in Barataria Bay and on Grand Isle, Louisiana, after the Deepwater Horizon Oil Spill

    NASA Astrophysics Data System (ADS)

    Finkelstein, D. B.; Schimmelmann, A.; Rosenheim, B. E.

    2012-12-01

    We present time-series of bulk hydrocarbon geochemical and compound specific isotopic data of oiled and tarry sediment deposits from Grand Isle and Barataria Bay, Louisiana. Samples were taken between 46 days and 694 days after the Macondo well blowout, and analyzed for bulk hydrocarbon stable carbon and hydrogen isotope ratios, n-alkane and other organic molecular characteristics, ramped pyrolysis stable carbon ratios and radiocarbon content, and compound specific isotope analysis. Bulk and compound specific stable hydrogen isotopes point to slight 2H-enrichment attributable to water washing during transport to Grand Isle and Barataria Bay, followed by more subtle changes after deposition that depended in part on the wave energy available locally. Characterization of the n-alkane distributions through time identified subtle shifts in the dominant n-alkanes from water washing and terrestrial degradation. The loss of high molecular weight n-alkanes and an increase in the unresolved complex mixture after day 337 is consistent with a shift from slight to moderate biodegradation. More significant variations were observed in elemental H:C ratios, whereas bulk stable carbon isotope values showed small increases through time. Ramped pyrolysis analyses illustrated relatively volatile and reactive petroleum-derived components were present during the first year following the spill, but they ultimately became less apparent during later sampling. Isotope results from different ramped pyrolysis components are discussed. Compound specific isotope analysis indicate that a combination of variables (e.g., tidal water washing and biodegradation) may impact degradation during the first 200 days. This period was followed by a mixing of Macondo and non-Macondo hydrocarbons in the environment. In sum, our analyses show the complementary roles of abiotic and biotic factors in degradation of the Deepwater Horizon oil that was deposited in different environments of coastal Louisiana.

  15. New Horizons at Pluto

    NASA Astrophysics Data System (ADS)

    Schenk, Paul; Nimmo, Francis

    2016-06-01

    The New Horizons mission has revealed Pluto and its moon Charon to be geologically active worlds. The familiar, yet exotic, landforms suggest that geologic processes operate similarly across the Solar System, even in its cold outer reaches.

  16. Infrared horizon locator

    NASA Technical Reports Server (NTRS)

    Jalink, A., Jr. (Inventor)

    1973-01-01

    A precise method and apparatus for locating the earth's infrared horizon from space that is independent of season and latitude is described. First and second integrations of the earth's radiance profile are made from space to earth with the second delayed with respect to the first. The second integration is multiplied by a predetermined constant R and then compared with the first integration. When the two are equal the horizon is located.

  17. Effect of extending the photoperiod with low-intensity red or far-red light on the timing of shoot elongation and flower-bud formation of 1-year-old Japanese pear (Pyrus pyrifolia).

    PubMed

    Ito, Akiko; Saito, Takanori; Nishijima, Takaaki; Moriguchi, Takaya

    2014-05-01

    To investigate the effects of light quality (wavelength) on shoot elongation and flower-bud formation in Japanese pear (Pyrus pyrifolia (Burm. f.) Nakai), we treated 1-year-old trees with the following: (i) 8 h sunlight + 16 h dark (SD); (ii) 8 h sunlight + 16 h red light (LD(SD + R)); or (iii) 8 h sunlight + 16 h far-red (FR) light (LD(SD + FR)) daily for 4 months from early April (before the spring flush) until early August in 2009 and 2010. In both years, shoot elongation stopped earlier in the LD(SD + FR) treatment than in the SD and LD(SD + R) treatments. After 4 months of treatments, 21% (2009) or 40% (2010) of LD(SD + FR)-treated trees formed flower buds in the shoot apices, whereas all the shoot apices from SD or LD(SD + R)-treated plants remained vegetative. With an additional experiment conducted in 2012, we confirmed that FR light at 730 nm was the most efficacious wavelength to induce flower-bud formation. Reverse transcription-quantitative polymerase chain reaction revealed that the expression of two floral meristem identity gene orthologues, LEAFY (PpLFY2a) and APETALA1 (PpMADS2-1a), were up-regulated in the shoot apex of LD(SD + FR). In contrast, the expression of a flowering repressor gene, TERMINAL FLOWER 1 (PpTFL1-1a, PpTFL1-2a), was down-regulated. In addition, expression of an orthologue of the flower-promoting gene FLOWERING LOCUS T (PpFT1a) was positively correlated with flower-bud formation, although the expression of another orthologue, PpFT2a, was negatively correlated with shoot growth. Biologically active cytokinin and gibberellic acid concentrations in shoot apices were reduced with LD(SD + FR) treatment. Taken together, our results indicate that pear plants are able to regulate flowering in response to the R : FR ratio. Furthermore, LD(SD + FR) treatment terminated shoot elongation and subsequent flower-bud formation in the shoot apex at an earlier time, possibly by influencing the expression of flowering-related genes and modifying

  18. Black holes with bottle-shaped horizons

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Teo, Edward

    2016-06-01

    We present a new class of four-dimensional AdS black holes with noncompact event horizons of finite area. The event horizons are topologically spheres with one puncture, with the puncture pushed to infinity in the form of a cusp. Because of the shape of their event horizons, we call such black holes "black bottles." The solution was obtained as a special case of the Plebański-Demiański solution, and may describe either static or rotating black bottles. For certain ranges of parameters, an acceleration horizon may also appear in the space-time. We study the full parameter space of the solution, and the various limiting cases that arise. In particular, we show how the rotating black hole recently discovered by Klemm arises as a special limit.

  19. Birth records from Swiss married couples analyzed over the past 35 years reveal an aging of first-time mothers by 5.1 years while the interpregnancy interval has shortened.

    PubMed

    Kalberer, Urs; Baud, David; Fontanet, Arnaud; Hohlfeld, Patrick; de Ziegler, Dominique

    2009-12-01

    Although the general trend for delaying childbearing is generally viewed as causing infertility, its consequences on the interpregnancy interval have been unknown. A study of birth records for Swiss married women from 1969 to 2006 revealed that the woman's age at first birth has increased from 25.0 to 30.1 years, whereas calculated theoretical interpregnancy intervals after the first and second child decreased from 23.2 to 13 and from 22.4 to 7.9 months, respectively. PMID:19608170

  20. Firewall or smooth horizon?

    NASA Astrophysics Data System (ADS)

    Ori, Amos

    2016-01-01

    Almheiri, Marolf, Polchinski, and Sully pointed out that for a sufficiently old black hole (BH), the set of assumptions known as the complementarity postulates appears to be inconsistent with the assumption of local regularity at the horizon. They concluded that the horizon of an old BH is likely to be the locus of local irregularity, a "firewall". Here I point out that if one adopts a different assumption, namely that semiclassical physics holds throughout its anticipated domain of validity, then the inconsistency is avoided, and the horizon retains its regularity. In this alternative view-point, the vast portion of the original BH information remains trapped inside the BH throughout the semiclassical domain of evaporation, and possibly leaks out later on. This appears to be an inevitable outcome of semiclassical gravity (if assumed to apply throughout its anticipated domain of validity).

  1. New Horizons Launch Contingency Effort

    NASA Astrophysics Data System (ADS)

    Chang, Yale; Lear, Matthew H.; McGrath, Brian E.; Heyler, Gene A.; Takashima, Naruhisa; Owings, W. Donald

    2007-01-01

    On 19 January 2006 at 2:00 PM EST, the NASA New Horizons spacecraft (SC) was launched from the Cape Canaveral Air Force Station (CCAFS), FL, onboard an Atlas V 551/Centaur/STAR™ 48B launch vehicle (LV) on a mission to explore the Pluto Charon planetary system and possibly other Kuiper Belt Objects. It carried a single Radioisotope Thermoelectric Generator (RTG). As part of the joint NASA/US Department of Energy (DOE) safety effort, contingency plans were prepared to address the unlikely events of launch accidents leading to a near-pad impact, a suborbital reentry, an orbital reentry, or a heliocentric orbit. As the implementing organization. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) had expanded roles in the New Horizons launch contingency effort over those for the Cassini mission and Mars Exploration Rovers missions. The expanded tasks included participation in the Radiological Control Center (RADCC) at the Kennedy Space Center (KSC), preparation of contingency plans, coordination of space tracking assets, improved aerodynamics characterization of the RTG's 18 General Purpose Heat Source (GPHS) modules, and development of spacecraft and RTG reentry breakup analysis tools. Other JHU/APL tasks were prediction of the Earth impact footprints (ElFs) for the GPHS modules released during the atmospheric reentry (for purposes of notification and recovery), prediction of the time of SC reentry from a potential orbital decay, pre-launch dissemination of ballistic coefficients of various possible reentry configurations, and launch support of an Emergency Operations Center (EOC) on the JHU/APL campus. For the New Horizons launch, JHU/APL personnel at the RADCC and at the EOC were ready to implement any real-time launch contingency activities. A successful New Horizons launch and interplanetary injection precluded any further contingency actions. The New Horizons launch contingency was an interagency effort by several organizations. This paper

  2. Stable predictive control horizons

    NASA Astrophysics Data System (ADS)

    Estrada, Raúl; Favela, Antonio; Raimondi, Angelo; Nevado, Antonio; Requena, Ricardo; Beltrán-Carbajal, Francisco

    2012-04-01

    The stability theory of predictive and adaptive predictive control for processes of linear and stable nature is based on the hypothesis of a physically realisable driving desired trajectory (DDT). The formal theoretical verification of this hypothesis is trivial for processes with a stable inverse, but it is not for processes with an unstable inverse. The extended strategy of predictive control was developed with the purpose of overcoming methodologically this stability problem and it has delivered excellent performance and stability in its industrial applications given a suitable choice of the prediction horizon. From a theoretical point of view, the existence of a prediction horizon capable of ensuring stability for processes with an unstable inverse was proven in the literature. However, no analytical solution has been found for the determination of the prediction horizon values which guarantee stability, in spite of the theoretical and practical interest of this matter. This article presents a new method able to determine the set of prediction horizon values which ensure stability under the extended predictive control strategy formulation and a particular performance criterion for the design of the DDT generically used in many industrial applications. The practical application of this method is illustrated by means of simulation examples.

  3. Boosted apparent horizons

    NASA Astrophysics Data System (ADS)

    Akcay, Sarp

    Boosted black holes play an important role in General Relativity (GR), especially in relation to the binary black hole problem. Solving Einstein vac- uum equations in the strong field regime had long been the holy grail of numerical relativity until the significant breakthroughs made in 2005 and 2006. Numerical relativity plays a crucial role in gravitational wave detection by providing numerically generated gravitational waveforms that help search for actual signatures of gravitational radiation exciting laser interferometric de- tectors such as LIGO, VIRGO and GEO600 here on Earth. Binary black holes orbit each other in an ever tightening adiabatic inspiral caused by energy loss due to gravitational radiation emission. As the orbits shrinks, the holes speed up and eventually move at relativistic speeds in the vicinity of each other (separated by ~ 10M or so where 2M is the Schwarzschild radius). As such, one must abandon the Newtonian notion of a point mass on a circular orbit with tangential velocity and replace it with the concept of black holes, cloaked behind spheroidal event horizons that become distorted due to strong gravity, and further appear distorted because of Lorentz effects from the high orbital velocity. Apparent horizons (AHs) are 2-dimensional boundaries that are trapped surfaces. Conceptually, one can think of them as 'quasi-local' definitions for a black hole horizon. This will be explained in more detail in chapter 2. Apparent horizons are especially important in numerical relativity as they provide a computationally efficient way of describing and locating a black hole horizon. For a stationary spacetime, apparent horizons are 2-dimensional cross-sections of the event horizon, which is itself a 3-dimensional null surface in spacetime. Because an AH is a 2-dimensional cross-section of an event horizon, its area remains invariant under distortions due to Lorentz boosts although its shape changes. This fascinating property of the AH can be

  4. Instability of enclosed horizons

    NASA Astrophysics Data System (ADS)

    Kay, Bernard S.

    2015-03-01

    We point out that there are solutions to the scalar wave equation on dimensional Minkowski space with finite energy tails which, if they reflect off a uniformly accelerated mirror due to (say) Dirichlet boundary conditions on it, develop an infinite stress-energy tensor on the mirror's Rindler horizon. We also show that, in the presence of an image mirror in the opposite Rindler wedge, suitable compactly supported arbitrarily small initial data on a suitable initial surface will develop an arbitrarily large stress-energy scalar near where the two horizons cross. Also, while there is a regular Hartle-Hawking-Israel-like state for the quantum theory between these two mirrors, there are coherent states built on it for which there are similar singularities in the expectation value of the renormalized stress-energy tensor. We conjecture that in other situations with analogous enclosed horizons such as a (maximally extended) Schwarzschild black hole in equilibrium in a (stationary spherical) box or the (maximally extended) Schwarzschild-AdS spacetime, there will be similar stress-energy singularities and almost-singularities—leading to instability of the horizons when gravity is switched on and matter and gravity perturbations are allowed for. All this suggests it is incorrect to picture a black hole in equilibrium in a box or a Schwarzschild-AdS black hole as extending beyond the past and future horizons of a single Schwarzschild (/Schwarzschild-AdS) wedge. It would thus provide new evidence for 't Hooft's brick wall model while seeming to invalidate the picture in Maldacena's ` Eternal black holes in AdS'. It would thereby also support the validity of the author's matter-gravity entanglement hypothesis and of the paper ` Brick walls and AdS/CFT' by the author and Ortíz.

  5. Spacetimes containing slowly evolving horizons

    SciTech Connect

    Kavanagh, William; Booth, Ivan

    2006-08-15

    Slowly evolving horizons are trapping horizons that are ''almost'' isolated horizons. This paper reviews their definition and discusses several spacetimes containing such structures. These include certain Vaidya and Tolman-Bondi solutions as well as (perturbatively) tidally distorted black holes. Taking into account the mass scales and orders of magnitude that arise in these calculations, we conjecture that slowly evolving horizons are the norm rather than the exception in astrophysical processes that involve stellar-scale black holes.

  6. Smooth horizons and quantum ripples

    NASA Astrophysics Data System (ADS)

    Golovnev, Alexey

    2015-05-01

    Black holes are unique objects which allow for meaningful theoretical studies of strong gravity and even quantum gravity effects. An infalling and a distant observer would have very different views on the structure of the world. However, a careful analysis has shown that it entails no genuine contradictions for physics, and the paradigm of observer complementarity has been coined. Recently this picture was put into doubt. In particular, it was argued that in old black holes a firewall must form in order to protect the basic principles of quantum mechanics. This AMPS paradox has already been discussed in a vast number of papers with different attitudes and conclusions. Here we want to argue that a possible source of confusion is the neglect of quantum gravity effects. Contrary to widespread perception, it does not necessarily mean that effective field theory is inapplicable in rather smooth neighbourhoods of large black hole horizons. The real offender might be an attempt to consistently use it over the huge distances from the near-horizon zone of old black holes to the early radiation. We give simple estimates to support this viewpoint and show how the Page time and (somewhat more speculative) scrambling time do appear.

  7. On the Bartnik mass of apparent horizons

    NASA Astrophysics Data System (ADS)

    Mantoulidis, Christos; Schoen, Richard

    2015-10-01

    In this paper we characterize the intrinsic geometry of apparent horizons (outermost marginally outer trapped surfaces) in asymptotically flat spacetimes; that is, the Riemannian metrics on the two sphere which can arise. Furthermore we determine the minimal ADM mass of a spacetime containing such an apparent horizon. The results are conveniently formulated in terms of the quasi-local mass introduced by Bartnik (1989 Phys. Rev. Lett. 62 2346-8). The Hawking mass provides a lower bound for Bartnik’s quasilocal mass on apparent horizons by way of Penrose’s conjecture on time symmetric slices, proven in 1997 by Huisken and Ilmanen (2001 J. Differ. Geom. 59 353-437) and in full generality in 1999 by Bray (2001 J. Differ. Geom. 59 177-267). We compute Bartnik’s mass for all non-degenerate apparent horizons and show that it coincides with the Hawking mass. As a corollary we disprove a conjecture due to Gibbons in the spirit of Thorne’s hoop conjecture (Gibbons 2009 arXiv:0903.1580), and construct a new large class of examples of apparent horizons with the integral of the negative part of the Gauss curvature arbitrarily large.

  8. Who Considers Teaching and Who Teaches? First-Time 2007-08 Bachelor's Degree Recipients by Teaching Status 1 Year after Graduation. Stats in Brief. NCES 2014-002

    ERIC Educational Resources Information Center

    Staklis, Sandra; Henke, Robin

    2013-01-01

    This Statistics in Brief examines the teaching status of 2007-08 first-time bachelor's degree recipients one year after graduation. The analysis compares four groups with respect to their teaching experiences or interest in teaching: those who taught either before or after receiving their bachelor's degree, those who prepared to teach…

  9. The Horizon Report: 2009 Australia-New Zealand Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Levine, A.; Smith, R.; Smythe, T.; Stone, S.

    2009-01-01

    The New Media Consortium's Horizon Project is an ongoing research project that aims to identify and describe emerging technologies likely to have a large impact on teaching, learning, or creative inquiry within education around the globe over a five-year time period. The project's central products are the "Horizon Reports", an annual series of…

  10. New Horizons at Pluto

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Artist's concept of the New Horizons spacecraft as it approaches Pluto and its largest moon, Charon, in July 2015. The craft's miniature cameras, radio science experiment, ultraviolet and infrared spectrometers and space plasma experiments will characterize the global geology and geomorphology of Pluto and Charon, map their surface compositions and temperatures, and examine Pluto's atmosphere in detail. The spacecraft's most prominent design feature is a nearly 7-foot (2.1-meter) dish antenna, through which it will communicate with Earth from as far as 4.7 billion miles (7.5 billion kilometers) away.

  11. Internet's critical path horizon

    NASA Astrophysics Data System (ADS)

    Valverde, S.; Solé, R. V.

    2004-03-01

    Internet is known to display a highly heterogeneous structure and complex fluctuations in its traffic dynamics. Congestion seems to be an inevitable result of user's behavior coupled to the network dynamics and it effects should be minimized by choosing appropriate routing strategies. But what are the requirements of routing depth in order to optimize the traffic flow? In this paper we analyse the behavior of Internet traffic with a topologically realistic spatial structure as described in a previous study [S.-H. Yook et al., Proc. Natl Acad. Sci. USA 99, 13382 (2002)]. The model involves self-regulation of packet generation and different levels of routing depth. It is shown that it reproduces the relevant key, statistical features of Internet's traffic. Moreover, we also report the existence of a critical path horizon defining a transition from low-efficient traffic to highly efficient flow. This transition is actually a direct consequence of the web's small world architecture exploited by the routing algorithm. Once routing tables reach the network diameter, the traffic experiences a sudden transition from a low-efficient to a highly-efficient behavior. It is conjectured that routing policies might have spontaneously reached such a compromise in a distributed manner. Internet would thus be operating close to such critical path horizon.

  12. Horizon thermodynamics and spacetime mappings

    NASA Astrophysics Data System (ADS)

    Faraoni, Valerio; Vitagliano, Vincenzo

    2014-03-01

    When black holes are dynamical, event horizons are replaced by apparent and trapping horizons. Conformal and Kerr-Schild transformations are widely used in relation to dynamical black holes, and we study the behavior under such transformations of quantities related to the thermodynamics of these horizons, such as the Misner-Sharp-Hernandez mass (internal energy), the Kodama vector, surface gravity, and temperature. The transformation properties are not those expected on the basis of naive arguments.

  13. Transverse deformations of extreme horizons

    NASA Astrophysics Data System (ADS)

    Li, Carmen; Lucietti, James

    2016-04-01

    We consider the inverse problem of determining all extreme black hole solutions to the Einstein equations with a prescribed near-horizon geometry. We investigate this problem by considering infinitesimal deformations of the near-horizon geometry along transverse null geodesics. We show that, up to a gauge transformation, the linearised Einstein equations reduce to an elliptic PDE for the extrinsic curvature of a cross-section of the horizon. We deduce that for a given near-horizon geometry there exists a finite dimensional moduli space of infinitesimal transverse deformations. We then establish a uniqueness theorem for transverse deformations of the extreme Kerr horizon. In particular, we prove that the only smooth axisymmetric transverse deformation of the near-horizon geometry of extreme Kerr, such that cross-sections of the horizon are marginally trapped surfaces, corresponds to that of the extreme Kerr black hole. Furthermore, we determine all smooth and biaxisymmetric transverse deformations of the near-horizon geometry of the five-dimensional extreme Myers-Perry black hole with equal angular momenta. We find a three parameter family of solutions such that cross-sections of the horizon are marginally trapped, which is more general than the known black hole solutions. We discuss the possibility that they correspond to new five-dimensional vacuum black holes.

  14. Technologies on the Horizon: Teachers Respond to the Horizon Report

    ERIC Educational Resources Information Center

    Hodges, Charles B.; Prater, Alyssa H.

    2014-01-01

    The purpose of this study was to investigate teachers' beliefs regarding the integration of technologies from the 2011 K-12 edition of the "Horizon Report" into their local, public school contexts. Teachers read the "Horizon Report" and then participated in an asynchronous, threaded discussion focusing on technologies they…

  15. Telescopic horizon scanning.

    PubMed

    Koenderink, Jan

    2014-12-20

    The problem of "distortionless" viewing with terrestrial telescopic systems (mainly "binoculars") remains problematic. The so called "globe effect" is only partially counteracted in modern designs. Theories addressing the phenomenon have never reached definitive closure. In this paper, we show that exact distortionless viewing with terrestrial telescopic systems is not possible in general, but that it is in principle possible in-very frequent in battle field and marine applications-the case of horizon scanning. However, this involves cylindrical optical elements. For opto-electronic systems, a full solution is more readily feasible. The solution involves a novel interpretation of the relevant constraints and objectives. For final design decisions, it is not necessary to rely on a corpus of psychophysical (or ergonomic) data, although one has to decide whether the instrument is intended as an extension of the eye or as a "pictorial" device. PMID:25608206

  16. Resolving Lifshitz Horizons

    SciTech Connect

    Harrison, Sarah; Kachru, Shamit; Wang, Huajia; /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC

    2012-04-24

    Via the AdS/CFT correspondence, ground states of field theories at finite charge density are mapped to extremal black brane solutions. Studies of simple gravity + matter systems in this context have uncovered wide new classes of extremal geometries. The Lifshitz metrics characterizing field theories with non-trivial dynamical critical exponent z {ne} 1 emerge as one common endpoint in doped holographic toy models. However, the Lifshitz horizon exhibits mildly singular behaviour - while curvature invariants are finite, there are diverging tidal forces. Here we show that in some of the simplest contexts where Lifshitz metrics emerge, Einstein-Maxwell-dilaton theories, generic corrections lead to a replacement of the Lifshitz metric, in the deep infrared, by a re-emergent AdS{sub 2} x R{sup 2} geometry. Thus, at least in these cases, the Lifshitz scaling characterizes the physics over a wide range of energy scales, but the mild singularity is cured by quantum or stringy effects.

  17. Fluctuating black hole horizons

    NASA Astrophysics Data System (ADS)

    Mei, Jianwei

    2013-10-01

    In this paper we treat the black hole horizon as a physical boundary to the spacetime and study its dynamics following from the Gibbons-Hawking-York boundary term. Using the Kerr black hole as an example we derive an effective action that describes, in the large wave number limit, a massless Klein-Gordon field living on the average location of the boundary. Complete solutions can be found in the small rotation limit of the black hole. The formulation suggests that the boundary can be treated in the same way as any other matter contributions. In particular, the angular momentum of the boundary matches exactly with that of the black hole, suggesting an interesting possibility that all charges (including the entropy) of the black hole are carried by the boundary. Using this as input, we derive predictions on the Planck scale properties of the boundary.

  18. The Horizon Report. 2007 Edition

    ERIC Educational Resources Information Center

    New Media Consortium, 2007

    2007-01-01

    This fourth edition of the New Media Consortium's (NMC) annual "Horizon Report" describes the continuing work of the Horizon Project, a research-oriented effort that seeks to identify and describe emerging technologies likely to have a large impact on teaching, learning, or creative expression within higher education. Drawing on ongoing…

  19. The Horizon Report. 2006 Edition

    ERIC Educational Resources Information Center

    New Media Consortium, 2006

    2006-01-01

    This third edition of the New Media Consortium's (NMC) annual "Horizon Report" describes the continuing work of the Horizon Project, a research-oriented effort that seeks to identify and describe emerging technologies likely to have a large impact on teaching, learning, or creative expression within higher education. Drawing on ongoing discussions…

  20. The Horizon Report. 2004 Edition

    ERIC Educational Resources Information Center

    New Media Consortium, 2004

    2004-01-01

    This first edition of the New Media Consortium's (NMC) annual "Horizon Report" details findings of the Horizon Project, a research-oriented effort that seeks to identify and describe emerging technologies likely to have a large impact on teaching, learning, or creative expression within higher education. Drawing on an ongoing series of interviews…

  1. The Horizon Report. 2005 Edition

    ERIC Educational Resources Information Center

    New Media Consortium, 2005

    2005-01-01

    This second edition of the New Media Consortium's (NMC) annual "Horizon Report" describes the continuing work of the Horizon Project, a research-oriented effort that seeks to identify and describe emerging technologies likely to have a large impact on teaching, learning, or creative expression within higher education. Drawing on an ongoing series…

  2. Are We Under-Estimating Mercury in Soils? Experimental Acidification and Sample Collection Timing Demonstrate Variability in Estimates of Mercury in O-Horizon Soils at a Maine Site

    NASA Astrophysics Data System (ADS)

    Nelson, S. J.; Johnson, K. B.

    2009-12-01

    Sampling protocols, including sample timing, collection methods, preservation, and preparation, can strongly influence the results of any analysis. Organic soil horizons are a large pool of mercury (Hg) in most temperate, forested sites; minimizing the potential for under- or over- estimates in this medium is critical for discerning the fate and transport of Hg. Detailed guidance is available for ultra-clean and semi-clean handling for Hg sampling in surface waters. However, neither guidance regarding the proper time of year to sample soils nor methodological studies regarding post-sampling preservation and handling were available in the scientific literature for soil Hg sampling. Here we report on pilot work that (1) provides data for Hg in soils (O-horizon) through an entire year, to determine whether seasonality affects Hg estimates; and (2) documents the effect of treating a soil with acidic water prior to preparation and analysis. We collected O-horizon soil samples monthly from a single plot during 2008, and analyzed them for total Hg. Each month, samples were split; half were ‘control’ samples (dried then analyzed) and half were ‘acidified’ (treated with acidic (pH 2.0) ultrapure water prior to drying and analysis). We observed: (1) a three-fold range of Hg values (148-446 ppb) for the control samples (all collected within the same 2-m2 plot), varying across the twelve months in 2008 during which samples were collected; (2) differences of ~15-20% between acidified and control samples; and, (3) an apparent loss of ~100 ppb of Hg (~22%) if acidification of the dry sample was delayed a day or more. Soils collected when the antecedent period had been wet lost Hg when soils were treated with pH 2.0 solution, potentially because soluble Hg in solution could have been leached during acid treatment. This finding may help to explain why researchers have seen large pulses of Hg in streamwater flux during snowmelt. Further, our results may help to inform

  3. On the differentiability order of horizons

    NASA Astrophysics Data System (ADS)

    Szeghy, D.

    2016-06-01

    Let M be a time oriented Lorentzian manifold and H\\subset M a horizon. We will show that the differentiability order of the horizon can change only once along a generator, i.e. the following holds. If γ :I\\to H is a generator, thus, an inextendable past directed light-like geodesic on the horizon, where I=(α ,β ) or [α ,β ), then there exists a unique parameter {t}0\\in [α ,β ] and a positive integer k≥slant 1 such that the following is true. The horizon H is exactly of class {C}k at γ (t), for every t\\in ({t}0,β ), moreover H is only differentiable, but not of class {C}1 at every point γ (t), for which t\\in (α ,{t}0]. Moreover, if γ (α ) is the endpoint of only one generator then for a suitable space-like submanifold R\\subset H the first cut point of R along γ is γ (α ). Furthermore, all the points γ (t), for which t\\in [α ,{t}0], are non-injectivity points of R along γ . Moreover, if H is smooth at an interior point of γ, then H is smooth at every point of γ. MSC 53C50

  4. What happens to Petrov classification, on horizons of axisymmetric dirty black holes

    SciTech Connect

    Tanatarov, I. V.; Zaslavskii, O. B.

    2014-02-15

    We consider axisymmetric stationary dirty black holes with regular non-extremal or extremal horizons, and compute their on-horizon Petrov types. The Petrov type (PT) in the frame of the observer crossing the horizon can be different from that formally obtained in the usual (but singular in the horizon limit) frame of an observer on a circular orbit. We call this entity the boosted Petrov type (BPT), as the corresponding frame is obtained by a singular boost from the regular one. The PT off-horizon can be more general than PT on-horizon and that can be more general than the BPT on horizon. This is valid for all regular metrics, irrespective of the extremality of the horizon. We analyze and classify the possible relations between the three characteristics and discuss the nature and features of the underlying singular boost. The three Petrov types can be the same only for space-times of PT D and O off-horizon. The mutual alignment of principal null directions and the generator in the vicinity of the horizon is studied in detail. As an example, we also analyze a special class of metrics with utra-extremal horizons (for which the regularity conditions look different from the general case) and compare their off-horizon and on-horizon algebraic structure in both frames.

  5. Social pharmacology: expanding horizons.

    PubMed

    Maiti, Rituparna; Alloza, José Luis

    2014-01-01

    In the current modern and global society, social changes are in constant evolution due to scientific progress (technology, culture, customs, and hygiene) and produce the freedom in individuals to take decisions by themselves or with their doctors toward drug consumption. In the arena of marketed drug products which includes society, individual, administration, and pharmaceutical industry, the young discipline emerged is social pharmacology or sociopharmacology. This science arises from clinical pharmacology, and deals with different parameters, which are important in creating knowledge on marketed drugs. However, the scope of "social pharmacology" is not covered by the so-called "Phase IV" alone, but it is the science that handles the postmarketing knowledge of drugs. The social pharmacology studies the "life cycle" of any marketed pharmaceutical product in the social terrain, and evaluates the effects of the real environment under circumstances totally different in the drug development process. Therefore, there are far-reaching horizons, plural, and shared predictions among health professionals and other, for beneficial use of a drug, toward maximizing the benefits of therapy, while minimizing negative social consequences. PMID:24987168

  6. Social Pharmacology: Expanding horizons

    PubMed Central

    Maiti, Rituparna; Alloza, José Luis

    2014-01-01

    In the current modern and global society, social changes are in constant evolution due to scientific progress (technology, culture, customs, and hygiene) and produce the freedom in individuals to take decisions by themselves or with their doctors toward drug consumption. In the arena of marketed drug products which includes society, individual, administration, and pharmaceutical industry, the young discipline emerged is social pharmacology or sociopharmacology. This science arises from clinical pharmacology, and deals with different parameters, which are important in creating knowledge on marketed drugs. However, the scope of “social pharmacology” is not covered by the so-called “Phase IV” alone, but it is the science that handles the postmarketing knowledge of drugs. The social pharmacology studies the “life cycle” of any marketed pharmaceutical product in the social terrain, and evaluates the effects of the real environment under circumstances totally different in the drug development process. Therefore, there are far-reaching horizons, plural, and shared predictions among health professionals and other, for beneficial use of a drug, toward maximizing the benefits of therapy, while minimizing negative social consequences. PMID:24987168

  7. Apparent horizons in binary black hole spacetimes

    NASA Astrophysics Data System (ADS)

    Shoemaker, Deirdre Marie

    Over the last decade, advances in computing technology and numerical techniques have lead to the possible theoretical prediction of astrophysically relevant waveforms in numerical simulations. With the building of gravitational wave detectors such as the Laser Interferometric Gravitational-Wave Observatory, we stand at the epoch that will usher in the first experimental study of strong field general relativity. One candidate source for ground based detection of gravitational waveforms, the orbit and merger of two black holes, is of great interest to the relativity community. The binary black hole problem is the two-body problem in general relativity. It is a stringent dynamical test of the theory. The problem involves the evolution of the Einstein equation, a complex system of non-linear, dynamic, elliptic-hyperbolic equations intractable in closed form. Numerical relativists are now developing the technology to evolve the Einstein equation using numerical simulations. The generation of these numerical I codes is a ``theoretical laboratory'' designed to study strong field phenomena in general relativity. This dissertation reports the successful development and application of the first multiple apparent horizon tracker applied to the generic binary black hole problem. I have developed a method that combines a level set of surfaces with a curvature flow method. This method, which I call the level flow method, locates the surfaces of any apparent horizons in the spacetime. The surface location then is used to remove the singularities from the computational domain in the evolution code. I establish the following set of criteria desired in an apparent horizon tracker: (1)The robustness of the tracker due to its lack of dependence on small changes to the initial guess; (2)The generality of the tracker in its applicability to generic spacetimes including multiple back hole spacetimes; and (3)The efficiency of the tracker algorithm in CPU time. I demonstrate the apparent

  8. Near-horizon Kerr magnetosphere

    NASA Astrophysics Data System (ADS)

    Gralla, Samuel E.; Lupsasca, Alexandru; Strominger, Andrew

    2016-05-01

    We exploit the near-horizon conformal symmetry of rapidly spinning black holes to determine universal properties of their magnetospheres. Analytic expressions are derived for the limiting form of the magnetosphere in the near-horizon region. The symmetry is shown to imply that the black hole Meissner effect holds for free Maxwell fields but is generically violated for force-free fields. We further show that in the extremal limit, near-horizon plasma particles are infinitely boosted relative to accretion flow. Active galactic nuclei powered by rapidly spinning black holes are therefore natural sites for high-energy particle collisions.

  9. [Visual illusions and moving horizon].

    PubMed

    Zhdan'ko, I M; Chulaevskiĭ, A O; Kovalenko, P A

    2012-09-01

    Results of psychological "additional investigation" of the crash of Boeing-737, "Aeroflot-Nord" on 14.09.2008 near Perm are presented. 37 pilots from the one of the leading airline companies sensed the attitude and rolling out the aircraft to the forward flight under the moving horizon with straight display of bank and tangage (view from the aircraft to the ground) in model conditions. 29 pilots (78.4%) made a mistake at determining the roll direction and tangage, they made a mistake at determining the roll direction 61 times (16.4%) and 44 times at determining the tangage direction, in other words they confused left and right bank and also nose-up and nose-down. Visual illusions of mobility of space and handling of ground (instead of aircraft) during the flight were revealed in pilots. These illusions may be the important cause of the following crashes. The necessity of "back" faultless display of bank in all aircrafts of civil aviation and development of computer complex for training of visual spatial orientation is proved. PMID:23156114

  10. Quantum correlations through event horizons: Fermionic versus bosonic entanglement

    SciTech Connect

    Martin-Martinez, Eduardo; Leon, Juan

    2010-03-15

    We disclose the behavior of quantum and classical correlations among all the different spatial-temporal regions of a space-time with an event horizon, comparing fermionic with bosonic fields. We show the emergence of conservation laws for entanglement and classical correlations, pointing out the crucial role that statistics plays in the information exchange (and more specifically, the entanglement tradeoff) across horizons. The results obtained here could shed new light on the problem of information behavior in noninertial frames and in the presence of horizons, giving better insight into the black-hole information paradox.

  11. Quantum correlations through event horizons: Fermionic versus bosonic entanglement

    NASA Astrophysics Data System (ADS)

    Martín-Martínez, Eduardo; León, Juan

    2010-03-01

    We disclose the behavior of quantum and classical correlations among all the different spatial-temporal regions of a space-time with an event horizon, comparing fermionic with bosonic fields. We show the emergence of conservation laws for entanglement and classical correlations, pointing out the crucial role that statistics plays in the information exchange (and more specifically, the entanglement tradeoff) across horizons. The results obtained here could shed new light on the problem of information behavior in noninertial frames and in the presence of horizons, giving better insight into the black-hole information paradox.

  12. Area Theorem and Smoothness of Compact Cauchy Horizons

    NASA Astrophysics Data System (ADS)

    Minguzzi, E.

    2015-10-01

    We obtain an improved version of the area theorem for not necessarily differentiable horizons which, in conjunction with a recent result on the completeness of generators, allows us to prove that under the null energy condition every compactly generated Cauchy horizon is smooth and compact. We explore the consequences of this result for time machines, topology change, black holes and cosmic censorship. For instance, it is shown that compact Cauchy horizons cannot form in a non-empty spacetime which satisfies the stable dominant energy condition wherever there is some source content.

  13. The clinical outcome of scaphoid fracture malunion at 1 year.

    PubMed

    Forward, D P; Singh, H P; Dawson, S; Davis, T R C

    2009-02-01

    The aim of this study was to assess the effect of malunion of scaphoid fractures on the clinical outcome at 1 year. Forty-two consecutive patients with united scaphoid waist fractures which had been treated non-operatively underwent longitudinal CT scans to confirm union and assess malunion at 12 to 18 weeks after injury. A blind clinical assessment was made and the Patient Evaluation Measure (PEM) and DASH questionnaires were completed by all the patients 1 year after injury. The group consisted of 38 men and four women with a mean age of 31 years at the time of injury. Correlation analysis revealed no significant relationships between any of the outcome measures (range of motion, grip strength and PEM and DASH scores) and any of the three measures of malunion (height-to-length ratio, the dorsal cortical angle and the lateral intra-scaphoid angle). PMID:19129358

  14. Status of the JPL Horizons Ephemeris System

    NASA Astrophysics Data System (ADS)

    Giorgini, Jon D.

    2015-08-01

    Since 1996, the NASA/Jet Propulsion Laboratory on-line Horizons system has provided open access to the latest JPL orbit solutions through customizable ephemeris generation and searches. Currently, high-precision ephemerides for more than 683,000 objects are available: all known solar system bodies, several dozen spacecraft, system barycenters, and some libration points.Since inception, Horizons has produced 150 million ephemeris products in response to 70.4 million connections by 800,000 unique IP addresses. Recent usage is typically 6000 unique users requesting 4,000,000 ephemeris products per month.Horizons is freely accessible without an account and may be used and automated through any of three interfaces: interactive telnet connection, web-browser form, or by sending e-mail command-files.Asteroid and comet ephemerides are numerically integrated on request using JPL's DASTCOM5 database of initial conditions which is kept current by a separate process; as new measurements and discoveries are reported by the Minor Planet Center, they are automatically processed into new JPL orbit solutions. Radar targets and other objects of high interest have their orbit solutions manually examined and updated into the database.For asteroids and comets, SPK files may be dynamically created using Horizons. This is effectively a recording of the integrator output. The binary files may then be efficiently interpolated by user software to exactly reproduce the trajectory without having to duplicate the numerically integrated n-body dynamical model or PPN equations of motion.Other Horizons output is numerical and in the form of plain-text observer, vector, osculating element, and close-approach tables. More than one hundred quantities can be requested in various time-scales and coordinate systems. For asteroids and comets, statistical uncertainties can be mapped to output times to assess position and motion uncertainties.Horizons is consistent with the DE431 solar system solution

  15. The absence of horizon in black-hole formation

    NASA Astrophysics Data System (ADS)

    Ho, Pei-Ming

    2016-08-01

    With the back-reaction of Hawking radiation taken into consideration, the work of Kawai, Matsuo and Yokokura [1] has shown that, under a few assumptions, the collapse of matter does not lead to event horizon nor apparent horizon. In this paper, we relax their assumptions and elaborate on the space-time geometry of a generic collapsing body with spherical symmetry. The geometry outside the collapsing sphere is found to be approximated by the geometry outside the white-hole horizon, hence the collapsing matter remains outside the Schwarzschild radius. As particles in Hawking radiation are created in the vicinity of the collapsing matter, the information loss paradox is alleviated. Assuming that the collapsing body evaporates within finite time, there is no event horizon.

  16. Dynamical AdS strings across horizons

    NASA Astrophysics Data System (ADS)

    Ishii, Takaaki; Murata, Keiju

    2016-03-01

    We examine the nonlinear classical dynamics of a fundamental string in anti-de Sitter spacetime. The string is dual to the flux tube between an external quark-antiquark pair in {N}=4 super Yang-Mills theory. We perturb the string by shaking the endpoints and compute its time evolution numerically. We find that with sufficiently strong perturbations the string continues extending and plunges into the Poincaré horizon. In the evolution, effective horizons are also dynamically created on the string worldsheet. The quark and antiquark are thus causally disconnected, and the string transitions to two straight strings. The forces acting on the endpoints vanish with a power law whose slope depends on the perturbations. The condition for this transition to occur is that energy injection exceeds the static energy between the quark-antiquark pair.

  17. NEW HORIZONS IN SENSOR DEVELOPMENT

    PubMed Central

    Intille, Stephen S.; Lester, Jonathan; Sallis, James F.; Duncan, Glen

    2011-01-01

    Background Accelerometery and other sensing technologies are important tools for physical activity measurement. Engineering advances have allowed developers to transform clunky, uncomfortable, and conspicuous monitors into relatively small, ergonomic, and convenient research tools. New devices can be used to collect data on overall physical activity and in some cases posture, physiological state, and location, for many days or weeks from subjects during their everyday lives. In this review article, we identify emerging trends in several types of monitoring technologies and gaps in the current state of knowledge. Best practices The only certainty about the future of activity sensing technologies is that researchers must anticipate and plan for change. We propose a set of best practices that may accelerate adoption of new devices and increase the likelihood that data being collected and used today will be compatible with new datasets and methods likely to appear on the horizon. Future directions We describe several technology-driven trends, ranging from continued miniaturization of devices that provide gross summary information about activity levels and energy expenditure, to new devices that provide highly detailed information about the specific type, amount, and location of physical activity. Some devices will take advantage of consumer technologies, such as mobile phones, to detect and respond to physical activity in real time, creating new opportunities in measurement, remote compliance monitoring, data-driven discovery, and intervention. PMID:22157771

  18. Thermal history of the Sabero Coalfield (Southern Cantabrian Zone, NW Spain) as revealed by apatite fission track analyses from tonstein horizons: implications for timing of coalification

    NASA Astrophysics Data System (ADS)

    Botor, Dariusz; Anczkiewicz, Aneta A.

    2015-10-01

    Apatite fission track (AFT) central ages from Carboniferous (Stephanian) tonsteins of the Sabero Coalfield, NW Spain, range from 140.8 ± 7.5 to 65.8 ± 8.1 Ma (Cretaceous), with mean c-axis projected track length values ranging from 12.5 to 13.4 μm. Mean random vitrinite reflectance ( R r) of these samples ranges from 0.91 to 1.20 %, which can be translated into maximum palaeotemperatures of ca. 130 to 180 °C. All analysed samples experienced substantial post-depositional annealing. The considerably younger AFT ages compared to the depositional ages of the samples and R r data indicate the certainty of the occurrence of at least one heating event after the deposition of strata. The unimodal track length distributions, the relatively short mean track length, and the rather low standard deviation (SD) (1.0-1.6 μm) indicate a relatively simple thermal history that could be related to the post-Late Variscan heating event followed by prolonged residence in the apatite partial annealing zone (APAZ). Geological data combined with thermal models of AFT data indicate that Stephanian strata reached the maximum palaeotemperatures in the Permian period, which was therefore the major time of the coalification processes. The Permian magmatic activity was responsible for a high heat flow, which, with the added effect of sedimentary burial, could account for the resetting of the AFT system. It appears that the fault-related hydrothermal activity could have redistributed heat in areas of significant subsidence. Cooling occurred in the Triassic-Cretaceous times after a high heat flow Permian regime. A post-Permian maturation of the Stephanian organic matter is not very likely, since there is no evidence of a high Mesozoic burial that was sufficient to cause a significant increase in the palaeotemperatures. Finally, exhumation and associated erosion rates may possibly have been faster in the Tertiary, causing the present exposure of the studied rocks.

  19. Exact event horizon of a black hole merger

    NASA Astrophysics Data System (ADS)

    Emparan, Roberto; Martínez, Marina

    2016-08-01

    We argue that the event horizon of a binary black hole merger, in the extreme-mass-ratio limit where one of the black holes is much smaller than the other, can be described in an exact analytic way. This is done by tracing in the Schwarzschild geometry a congruence of null geodesics that approaches a null plane at infinity. Its form can be given explicitly in terms of elliptic functions, and we use it to analyze and illustrate the time-evolution of the horizon along the merger. We identify features such as the line of caustics at which light rays enter the horizon, and the critical point at which the horizons touch. We also compute several quantities that characterize these aspects of the merger.

  20. Finding KBO flyby targets for New Horizons

    NASA Astrophysics Data System (ADS)

    Spencer, John; Trilling, David; Buie, Marc; Parker, Alex; Tholen, David; Stern, S. Alan

    2014-08-01

    We propose to continue the search for Kuiper Belt Objects (KBOs) that can be reached by the New Horizons spacecraft after its 2015 Pluto flyby, by following up on KBOs discovered in 2014A. The first flyby of a small (~50 km) KBO would revolutionize our understanding of KBOs, providing information that can be extrapolated to hundreds of thousands of similar KBOs. Our 2011 search discovered two objects that could be targeted with less than twice the fuel that New Horizons has available, during excellent seeing, but seeing was insufficient to achieve this depth over the entire search area in 2012 or 2013. Deepening the search with time allocated in 2014A, taking advantage of lower star density and the shrinking search area, has a chance of finding a targetable object given sufficiently good seeing, especially with Hyper Suprime Cam. 2014B follow-up is essential to produce orbits good enough to determine targetability, and allow recovery in 2015. We will also continue to refine the orbits of other previously discovered objects, including ones that can be observed from a distance by New Horizons on its passage through the Kuiper Belt.

  1. New Horizons Pluto Flyby Guest Operations

    NASA Astrophysics Data System (ADS)

    Simon, M.; Turney, D.; Fisher, S.; Carr, S. S.

    2015-12-01

    On July 14, 2015, after 9.5 years of cruise, NASA's New Horizons spacecraft flew past the Pluto system to gather first images humankind had ever seen on Pluto and its five moons. While much has been discovered about the Pluto system since New Horizons launch in 2006, the system has never been imaged at high resolution and anticipation of the "First Light" of the Pluto system had been anticipated by planetary enthusiasts for decades. The Johns Hopkins Applied Physics Laboratory (APL), which built and operates New Horizons, was the focal point for gathering three distinct groups: science and engineering team members; media and public affairs representatives; and invited public, including VIP's. Guest operations activities were focused on providing information primarily to the invited public and VIP's. High level objectives for the Guest Operations team was set to entertain and inform the general public, offer media reaction shots, and to deconflict activities for the guests from media activities wherever possible. Over 2000 people arrived at APL in the days surrounding closest approach for guest, science or media operations tracks. Reaction and coverage of the Guest Operations events was universally positive and global in impact: iconic pictures of the auditorium waving flags during the moment of closest approach were published in media outlets on every continent. Media relations activities ensured coverage in all key media publications targeted for release, such as the New York Times, Science, Le Monde, and Nature. Social and traditional media coverage of the events spanned the globe. Guest operations activities are designed to ensure that a guest has a memorable experience and leaves with a lifelong memory of the mission and their partnership in the activity. Results, lessons learned, and other data from the New Horizons guest operations activity will be presented and analyzed.

  2. Choking - unconscious adult or child over 1 year

    MedlinePlus

    Choking - unconscious adult or child over 1 year; First aid - choking - unconscious adult or child over 1 year; ... or the local emergency number while you begin first aid and CPR. If you are alone, shout for ...

  3. Choking - unconscious adult or child over 1 year

    MedlinePlus

    ... choking - unconscious adult or child over 1 year; CPR - choking - unconscious adult or child over 1 year ... emergency number while you begin first aid and CPR. If you are alone, shout for help and ...

  4. NIF featured on BBC "Horizon"

    ScienceCinema

    Brian Cox

    2010-09-01

    The National Ignition Facility, the world's largest laser system, located at Lawrence Livermore National Laboratory, was featured in the BBC broadcast "Horizon" hosted by physicist Brian Cox. Here is the NIF portion of the program, which was entitled "Can We Make A Star On Earth?" This video is used with the express permission of the BBC.

  5. Common Ground: Expanding Our Horizons.

    ERIC Educational Resources Information Center

    McDevitt, Michele J.

    In "Common Ground: Dialogue, Understanding, and the Teaching of Composition," Kurt Spellmeyer seeks to familiarize students and teachers with the linguistic and cultural no-man's-land separating them. Reinstating the value of two writing conventions often used by traditional students--expressive and commonplaces--can help expand on the horizons of…

  6. New Horizons in Education, 2000.

    ERIC Educational Resources Information Center

    Ho, Kwok Keung, Ed.

    2000-01-01

    This document contains the May and November 2000 issues of "New Horizons in Education," with articles in English and Chinese. The May issue includes the following articles: "A Key to Successful Environmental Education: Teacher Trainees' Attitude, Behaviour, and Knowledge" (Kevin Chung Wai Lui, Eric Po Keung Tsang, Sing Lai Chan); "Critical…

  7. New Horizons Mission to Pluto

    NASA Technical Reports Server (NTRS)

    Delgado, Luis G.

    2011-01-01

    This slide presentation reviews the trajectory that will take the New Horizons Mission to Pluto. Included are photographs of the spacecraft, the launch vehicle, the assembled vehicle as it is being moved to the launch pad and the launch. Also shown are diagrams of the assembled parts with identifying part names.

  8. NIF featured on BBC "Horizon"

    SciTech Connect

    Brian Cox

    2010-01-12

    The National Ignition Facility, the world's largest laser system, located at Lawrence Livermore National Laboratory, was featured in the BBC broadcast "Horizon" hosted by physicist Brian Cox. Here is the NIF portion of the program, which was entitled "Can We Make A Star On Earth?" This video is used with the express permission of the BBC.

  9. Intracranial idiopathic hypertension: 1-year follow-up study.

    PubMed

    D'Amico, D; Curone, M; Erbetta, A; Farago', G; Bianchi-Marzoli, S; Ciasca, P; Bussone, G; Chiapparini, L

    2014-05-01

    Standard guidelines for ongoing management, as well as definitive data about the long-term course of idiopathic intracranial hypertension (IIH) are not available. The aim of this study was to compare several clinical and instrumental variables as assessed at the time of diagnosis and then after 1 year in a sample of IIH patients. A total of 21 patients were studied. Our results confirmed that headache and TVO are the most frequent symptoms in IIH patients, and that overweight is a very common feature. A trend towards a favorable outcome in patients followed for 1 year and treated by usual medical therapy was found: intracranial pressure was lower at follow-up; improvement of headache and transient visual obscurations, as well as of papilledema, was reported in most patients. On the other hand, neuroradiological findings (such as empty sella, perioptic subarachnoid space distension, narrowing of the transverse sinuses) were substantially stable at follow. These findings may be relevant for future research as far as understanding the role of different clinical and instrumental findings as diagnostic items as well as predictors of outcome in IIH. PMID:24867861

  10. Generic isolated horizons and their applications

    PubMed

    Ashtekar; Beetle; Dreyer; Fairhurst; Krishnan; Lewandowski; Wisniewski

    2000-10-23

    The notion of isolated horizons is extended to allow for distortion and rotation. Space-times containing a black hole, itself in equilibrium but possibly surrounded by radiation, satisfy these conditions. The framework has three types of applications: (i) it provides new tools to extract physics from strong field geometry; (ii) it leads to a generalization of the zeroth and first laws of black hole mechanics and sheds new light on the "origin" of the first law; and (iii) it serves as a point of departure for black hole entropy calculations in nonperturbative quantum gravity. PMID:11030951

  11. Art, the Urban Skyscraper, and Horizon Astronomy

    NASA Astrophysics Data System (ADS)

    Mooney, J. D.

    2016-01-01

    This presentation delineates the historiography and the iconography of my urban public sculptures which use skyscrapers as today's standing stones, markers for horizon astronomy. From 1977 to the present time, my work has engaged the public to “look up and see.” Through ephemeral works in the sky and over the water to large-scale rooftop sculptures in Los Angeles, Chicago, Atlanta, and Europe, viewers are oriented to the Milky Way, the summer triangle, and other celestial phenomena. This new urban scale art, transformative in context and gesture, has become part of the new cultural landscape.

  12. On tunneling across horizons

    NASA Astrophysics Data System (ADS)

    Vanzo, L.

    2011-07-01

    The tunneling method for stationary black holes in the Hamilton-Jacobi variant is reconsidered in the light of some critiques that have been moved against. It is shown that once the tunneling trajectories have been correctly identified the method is free from internal inconsistencies, it is manifestly covariant, it allows for the extension to spinning particles and it can even be used without solving the Hamilton-Jacobi equation. These conclusions borrow support on a simple analytic continuation of the classical action of a pointlike particle, made possible by the unique assumption that it should be analytic in the complexified Schwarzschild or Kerr-Newman space-time. A more general version of the Parikh-Wilczek method will also be proposed along these lines.

  13. The Malcolm horizon: History and future

    NASA Technical Reports Server (NTRS)

    Malcolm, R.

    1984-01-01

    The development of the Malcolm Horizon, a peripheral vision horizon used in flight simulation, is discussed. A history of the horizon display is presented as well as a brief overview of vision physiology, and the role balance plays is spatial orientation. Avenues of continued research in subconscious cockpit instrumentation are examined.

  14. Geometric properties of static Einstein-Maxwell dilaton horizons with a Liouville potential

    SciTech Connect

    Abdolrahimi, Shohreh; Shoom, Andrey A.

    2011-05-15

    We study nondegenerate and degenerate (extremal) Killing horizons of arbitrary geometry and topology within the Einstein-Maxwell-dilaton model with a Liouville potential (the EMdL model) in d-dimensional (d{>=}4) static space-times. Using Israel's description of a static space-time, we construct the EMdL equations and the space-time curvature invariants: the Ricci scalar, the square of the Ricci tensor, and the Kretschmann scalar. Assuming that space-time metric functions and the model fields are real analytic functions in the vicinity of a space-time horizon, we study the behavior of the space-time metric and the fields near the horizon and derive relations between the space-time curvature invariants calculated on the horizon and geometric invariants of the horizon surface. The derived relations generalize similar relations known for horizons of static four- and five-dimensional vacuum and four-dimensional electrovacuum space-times. Our analysis shows that all the extremal horizon surfaces are Einstein spaces. We present the necessary conditions for the existence of static extremal horizons within the EMdL model.

  15. Fermion tunneling from dynamical horizons

    NASA Astrophysics Data System (ADS)

    Di Criscienzo, R.; Vanzo, L.

    2008-06-01

    The instability against emission of fermionic particles by the trapping horizon of an evolving black hole is analyzed and confirmed using the Hamilton-Jacobi tunneling method. This method automatically selects one special expression for the surface gravity of a changing horizon. The results also apply to point masses embedded in an expanding universe. As a bonus of the tunneling method, we gain the insight that the surface gravity still defines a temperature parameter as long as the evolution is sufficiently slow that the black-hole pass through a sequence of quasi-equilibrium states, and that black holes should be semi-classically unstable even in a hypothetical world without bosonic fields.

  16. Penrose inequality and apparent horizons

    SciTech Connect

    Ben-Dov, Ishai

    2004-12-15

    A spherically symmetric spacetime is presented with an initial data set that is asymptotically flat, satisfies the dominant energy condition, and such that on this initial data M<{radical}(A/16{pi}), where M is the total mass and A is the area of the apparent horizon. This provides a counterexample to a commonly stated version of the Penrose inequality, though it does not contradict the true Penrose inequality.

  17. New Horizons Tracks an Asteroid

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The two 'spots' in this image are a composite of two images of asteroid 2002 JF56 taken on June 11 and June 12, 2006, with the Multispectral Visible Imaging Camera (MVIC) component of the New Horizons Ralph imager. In the bottom image, taken when the asteroid was about 3.36 million kilometers (2.1 million miles) away from the spacecraft, 2002 JF56 appears like a dim star. At top, taken at a distance of about 1.34 million kilometers (833,000 miles), the object is more than a factor of six brighter. The best current, estimated diameter of the asteroid is approximately 2.5 kilometers.

    The asteroid observation was a chance for the New Horizons team to test the spacecraft's ability to track a rapidly moving object. On June 13 New Horizons came to within about 102,000 kilometers of the small asteroid, when the spacecraft was nearly 368 million kilometers (228 million miles) from the Sun and about 273 million kilometers (170 million miles) from Earth.

  18. A receding horizon approach for dynamic UAV mission management

    NASA Astrophysics Data System (ADS)

    Cassandras, Christos G.; Li, Wei

    2003-09-01

    We consider a setting where multiple UAVs form a team cooperating to visit multiple targets to collect rewards associated with them. The team objective is to maximize the total reward accumulated over a given time interval. Complicating factors include uncertainties regarding the locations of targets and the effectiveness of collecting rewards, differences among vehicle capabilities, and the fact that rewards are time-varying. We describe a Receding Horizon (RH) control scheme which dynamically assigns vehicles to targets and simultaneously determines associated trajectories. This scheme is based on solving a sequence of optimization problems over a planning horizon and executing them over a shorter action horizon. We also describe a simulated battlespace environment designed to test UAV team missions and to illustrate how the RH scheme can achieve optimal performance with high probability.

  19. Beyond the veil: Inner horizon instability and holography

    SciTech Connect

    Balasubramanian, Vijay; Levi, Thomas S.

    2004-11-15

    We show that scalar perturbations of the eternal, rotating Banados-Teitelboim-Zanelli (BTZ) black hole should lead to an instability of the inner (Cauchy) horizon, preserving strong cosmic censorship. Because of backscattering from the geometry, plane-wave modes have a divergent stress tensor at the event horizon, but suitable wave packets avoid this difficulty, and are dominated at late times by quasinormal behavior. The wave packets have cuts in the complexified coordinate plane that are controlled by requirements of continuity, single-valuedness, and positive energy. Due to a focusing effect, regular wave packets nevertheless have a divergent stress energy at the inner horizon, signaling an instability. We propose that this instability, which is localized behind the event horizon, is detected holographically as a breakdown in the semiclassical computation of dual conformal field theory (CFT) expectation values in which the analytic behavior of wave packets in the complexified coordinate plane plays an integral role. In the dual field theory, this is interpreted as an encoding of physics behind the horizon in the entanglement between otherwise independent CFTs.

  20. Topological deformation of isolated horizons

    SciTech Connect

    Liko, Tomas

    2008-03-15

    We show that the Gauss-Bonnet term can have physical effects in four dimensions. Specifically, the entropy of a black hole acquires a correction term that is proportional to the Euler characteristic of the cross sections of the horizon. While this term is constant for a single black hole, it will be a nontrivial function for a system with dynamical topologies such as black-hole mergers: it is shown that for certain values of the Gauss-Bonnet parameter, the second law of black-hole mechanics can be violated.

  1. Variable horizon in a peridynamic medium

    SciTech Connect

    Silling, Stewart A.; Littlewood, David J.; Seleson, Pablo

    2015-12-10

    Here, a notion of material homogeneity is proposed for peridynamic bodies with variable horizon but constant bulk properties. A relation is derived that scales the force state according to the position-dependent horizon while keeping the bulk properties unchanged. Using this scaling relation, if the horizon depends on position, artifacts called ghost forces may arise in a body under a homogeneous deformation. These artifacts depend on the second derivative of the horizon and can be reduced by employing a modified equilibrium equation using a new quantity called the partial stress. Bodies with piecewise constant horizon can be modeled without ghost forces by using a simpler technique called a splice. As a limiting case of zero horizon, both the partial stress and splice techniques can be used to achieve local-nonlocal coupling. Computational examples, including dynamic fracture in a one-dimensional model with local-nonlocal coupling, illustrate the methods.

  2. Variable horizon in a peridynamic medium.

    SciTech Connect

    Silling, Stewart Andrew; Littlewood, David John; Seleson, Pablo

    2014-10-01

    A notion of material homogeneity is proposed for peridynamic bodies with vari- able horizon but constant bulk properties. A relation is derived that scales the force state according to the position-dependent horizon while keeping the bulk properties un- changed. Using this scaling relation, if the horizon depends on position, artifacts called ghost forces may arise in a body under homogeneous deformation. These artifacts de- pend on the second derivative of horizon and can be reduced by use of a modified equilibrium equation using a new quantity called the partial stress . Bodies with piece- wise constant horizon can be modeled without ghost forces by using a technique called a splice between the regions. As a limiting case of zero horizon, both partial stress and splice techniques can be used to achieve local-nonlocal coupling. Computational examples, including dynamic fracture in a one-dimensional model with local-nonlocal coupling, illustrate the methods.

  3. Variable horizon in a peridynamic medium

    DOE PAGESBeta

    Silling, Stewart A.; Littlewood, David J.; Seleson, Pablo

    2015-12-10

    Here, a notion of material homogeneity is proposed for peridynamic bodies with variable horizon but constant bulk properties. A relation is derived that scales the force state according to the position-dependent horizon while keeping the bulk properties unchanged. Using this scaling relation, if the horizon depends on position, artifacts called ghost forces may arise in a body under a homogeneous deformation. These artifacts depend on the second derivative of the horizon and can be reduced by employing a modified equilibrium equation using a new quantity called the partial stress. Bodies with piecewise constant horizon can be modeled without ghost forcesmore » by using a simpler technique called a splice. As a limiting case of zero horizon, both the partial stress and splice techniques can be used to achieve local-nonlocal coupling. Computational examples, including dynamic fracture in a one-dimensional model with local-nonlocal coupling, illustrate the methods.« less

  4. Theory underlying the peripheral vision horizon device

    NASA Technical Reports Server (NTRS)

    Money, K. E.

    1984-01-01

    Peripheral Vision Horizon Device (PVHD) theory states that the likelihood of pilot disorientation in flight is reduced by providing an artificial horizon that provides orientation information to peripheral vision. In considering the validity of the theory, three areas are explored: the use of an artificial horizon device over some other flight instrument; the use of peripheral vision over foveal vision; and the evidence that peripheral vision is well suited to the processing of orientation information.

  5. Caregiver burden at 1 year following severe traumatic brain injury.

    PubMed

    Marsh, N V; Kersel, D A; Havill, J H; Sleigh, J W

    1998-12-01

    Sixty-nine primary caregivers of adults with a severe traumatic brain injury (TBI) were assessed at 1-year post-injury. Caregivers completed questionnaires on the physical, cognitive, emotional, behavioural, and social functioning of the person with TBI. Caregiver objective burden, psychosocial functioning, and subjective burden were also assessed. Clinically significant levels of anxiety and depression were evident in over a third of the caregivers. Similarly, a quarter of the caregivers reported poor social adjustment. There was no consistent relationship between the prevalence of various types of objective burden and the level of subjective distress that resulted from these changes. The person with TBI's emotional difficulties, in particular their anger, apathy, and dependency, caused the greatest distress for caregivers. With regard to the impact that caregiving had on their own lives, caregivers were most distressed by the loss of personal free time. Results from a regression analysis indicated that the person with TBI's physical impairment, number of behavioural problems, and social isolation were the strongest predictors of caregiver burden. The impact that caring for a person with severe TBI can have on the extended family unit is discussed. PMID:9876864

  6. A MIP Model for Rolling Horizon Surgery Scheduling.

    PubMed

    Luo, Li; Luo, Yong; You, Yang; Cheng, Yuanjun; Shi, Yingkang; Gong, Renrong

    2016-05-01

    Most surgery scheduling is done 1 day in advance. Caused by lack of overall planning, this scheduling scheme often results in unbalanced occupancy time of the operating rooms. So we put forward a rolling horizon mixed integer programming model for the scheduling. Rolling horizon scheduling refers to a scheduling scheme in which cyclic surgical requests are taken into account. Surgical requests are updated daily. The completed surgeries are eliminated, and new surgeries are added to the scheduling list. Considering day-to-day demand for surgery, we develop a non-rolling scheduling model (NRSM) and a rolling horizon scheduling model (RSM). By comparing the two, we find that the quality of surgery scheduling is significantly influenced by the variation in demand from day to day. A rolling horizon scheduling will enable a more flexible planning of the pool of surgeries that have not been scheduled into this main blocks, and hence minimize the idle time of operating rooms. The strategy of the RSM helps balance the occupancy time among operating rooms. Using surgical data from five departments of the West China Hospital (WCH), we generate surgical demands randomly to compare the NRSM and the RSM. The results show the operating rooms' average utilization rate using RSM is significantly higher than when applying NRSM. PMID:27071394

  7. Spectroscopy of a weakly isolated horizon

    NASA Astrophysics Data System (ADS)

    Chen, Ge-Rui; Huang, Yong-Chang

    2016-06-01

    The spectroscopy of a weakly isolated horizon has been investigated. We obtain an equally spaced entropy spectrum with its quantum equal to the one given by Bekenstein (Phys Rev D 7:2333, 1973). We demonstrate that the quantization of entropy and area is a generic property of horizons which exists in a wide class of spacetimes admitting weakly isolated horizons. Our method based on the tunneling method also indicates that the entropy quantum of black hole horizons is closely related to Hawking temperature.

  8. Priority Questions and Horizon Scanning for Conservation: A Comparative Study

    PubMed Central

    Kark, Salit; Sutherland, William J.; Shanas, Uri; Klass, Keren; Achisar, Hila; Dayan, Tamar; Gavrieli, Yael; Justo-Hanani, Ronit; Mandelik, Yael; Orion, Nir; Pargament, David; Portman, Michelle; Reisman-Berman, Orna; Safriel, Uriel N.; Schaffer, Gad; Steiner, Noa; Tauber, Israel; Levin, Noam

    2016-01-01

    Several projects aimed at identifying priority issues for conservation with high relevance to policy have recently been completed in several countries. Two major types of projects have been undertaken, aimed at identifying (i) policy-relevant questions most imperative to conservation and (ii) horizon scanning topics, defined as emerging issues that are expected to have substantial implications for biodiversity conservation and policy in the future. Here, we provide the first overview of the outcomes of biodiversity and conservation-oriented projects recently completed around the world using this framework. We also include the results of the first questions and horizon scanning project completed for a Mediterranean country. Overall, the outcomes of the different projects undertaken (at the global scale, in the UK, US, Canada, Switzerland and in Israel) were strongly correlated in terms of the proportion of questions and/or horizon scanning topics selected when comparing different topic areas. However, some major differences were found across regions. There was large variation among regions in the percentage of proactive (i.e. action and response oriented) versus descriptive (non-response oriented) priority questions and in the emphasis given to socio-political issues. Substantial differences were also found when comparing outcomes of priority questions versus horizon scanning projects undertaken for the same region. For example, issues related to climate change, human demography and marine ecosystems received higher priority as horizon scanning topics, while ecosystem services were more emphasized as current priority questions. We suggest that future initiatives aimed at identifying priority conservation questions and horizon scanning topics should allow simultaneous identification of both current and future priority issues, as presented here for the first time. We propose that further emphasis on social-political issues should be explicitly integrated into future

  9. Priority Questions and Horizon Scanning for Conservation: A Comparative Study.

    PubMed

    Kark, Salit; Sutherland, William J; Shanas, Uri; Klass, Keren; Achisar, Hila; Dayan, Tamar; Gavrieli, Yael; Justo-Hanani, Ronit; Mandelik, Yael; Orion, Nir; Pargament, David; Portman, Michelle; Reisman-Berman, Orna; Safriel, Uriel N; Schaffer, Gad; Steiner, Noa; Tauber, Israel; Levin, Noam

    2016-01-01

    Several projects aimed at identifying priority issues for conservation with high relevance to policy have recently been completed in several countries. Two major types of projects have been undertaken, aimed at identifying (i) policy-relevant questions most imperative to conservation and (ii) horizon scanning topics, defined as emerging issues that are expected to have substantial implications for biodiversity conservation and policy in the future. Here, we provide the first overview of the outcomes of biodiversity and conservation-oriented projects recently completed around the world using this framework. We also include the results of the first questions and horizon scanning project completed for a Mediterranean country. Overall, the outcomes of the different projects undertaken (at the global scale, in the UK, US, Canada, Switzerland and in Israel) were strongly correlated in terms of the proportion of questions and/or horizon scanning topics selected when comparing different topic areas. However, some major differences were found across regions. There was large variation among regions in the percentage of proactive (i.e. action and response oriented) versus descriptive (non-response oriented) priority questions and in the emphasis given to socio-political issues. Substantial differences were also found when comparing outcomes of priority questions versus horizon scanning projects undertaken for the same region. For example, issues related to climate change, human demography and marine ecosystems received higher priority as horizon scanning topics, while ecosystem services were more emphasized as current priority questions. We suggest that future initiatives aimed at identifying priority conservation questions and horizon scanning topics should allow simultaneous identification of both current and future priority issues, as presented here for the first time. We propose that further emphasis on social-political issues should be explicitly integrated into future

  10. Choking first aid - adult or child over 1 year - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100222.htm Choking first aid - adult or child over 1 year - series—Part ... occur in as little as 4 minutes. Rapid first aid for choking can save a life. The universal ...

  11. Choking first aid - infant under 1 year - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100221.htm Choking first aid - infant under 1 year - series—Part 1 To ... Loss of consciousness if blockage is not cleared FIRST AID 1. DO NOT perform these steps if the ...

  12. The NMC Horizon Report: 2014 Library Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Adams Becker, S.; Estrada, V.; Freeman, A.

    2014-01-01

    The internationally recognized "NMC Horizon Report" series and regional "NMC Technology Outlooks" are part of the NMC Horizon Project, a 12-year effort established in 2002 that annually identifies and describes emerging technologies likely to have a large impact over the coming five years in every sector of education around the…

  13. Reconceptualizing Knowledge at the Mathematical Horizon

    ERIC Educational Resources Information Center

    Zazkis, Rina; Mamolo, Ami

    2011-01-01

    This article extends the notion of "knowledge at the mathematical horizon" or "horizon knowledge" introduced by Ball and colleagues as a part of teachers' subject matter knowledge. Our focus is on teachers' mathematical knowledge beyond the school curriculum, that is, on mathematics learnt during undergraduate college or university studies. We…

  14. The Horizon Report: 2010 Museum Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Witchey, H.; Smith, R.; Levine, A.; Haywood, K.

    2010-01-01

    The internationally recognized series of "Horizon Reports" is part of the New Media Consortium's Horizon Project, a comprehensive research venture established in 2002 that identifies and describes emerging technologies likely to have a large impact over the coming five years on a variety of sectors around the globe. This volume, the "2010 Horizon…

  15. Expanding your horizons in science and mathematics

    NASA Technical Reports Server (NTRS)

    Palmer, Cynthia E. A.

    1995-01-01

    The purpose of the 'Expanding Your Horizons in Science and Mathematics' program is to interest young women in grades six through twelve in a variety of careers where mathematics and science are important. Progress in encouraging young women to take courses in mathematics, science, and technological subjects is discussed. Also included are adult, student, and organizational information packets used for 'Expanding Your Horizons' conferences.

  16. Horizon Report: 2010 K-12 Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Smith, R.; Levine, A.; Haywood, K.

    2010-01-01

    The "Horizon Report" series is the most visible outcome of the New Media Consortium's Horizon Project, an ongoing research effort established in 2002 that identifies and describes emerging technologies likely to have a large impact on teaching, learning, research, or creative expression within education around the globe. This volume, the "2010…

  17. The NMC Horizon Report: 2015 Museum Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Adams Becker, S.; Estrada, V.; Freeman, A.

    2015-01-01

    The internationally recognized series of "Horizon Reports" is part of the New Media Consortium's Horizon Project, a comprehensive research venture established in 2002 that identifies and describes emerging technologies likely to have a large impact over the coming years on a variety of sectors around the globe. This "2015 Horizon…

  18. High-frequency over-the-horizon radar and ionospheric backscatter studies in China

    NASA Astrophysics Data System (ADS)

    Li, Le-Wei

    1998-09-01

    China is one of the countries that employs high-frequency over-the-horizon radars for both military and civil applications. The first Chinese high-frequency over-the horizon backscatter radar was developed in the 1970s. This paper briefly introduces the first Chinese over-the-horizon backscatter radar system and reviews ionospheric backscatter and propagation studies in China. The paper discusses the motivation for establishing over-the-horizon radar systems in China, the experimental system, target recognition and detection,and estimation of over-the-horizon radar availability. Observations of aircraft, large-scale traveling ionospheric disturbances, and the effects of a remote nuclear explosion are also presented. Finally, the real-time Chinese ionosonde network and frequency predictions using backscatter ionograms are discussed.

  19. Estimation of the Horizon in Photographed Outdoor Scenes by Human and Machine

    PubMed Central

    Herdtweck, Christian; Wallraven, Christian

    2013-01-01

    We present three experiments on horizon estimation. In Experiment 1 we verify the human ability to estimate the horizon in static images from only visual input. Estimates are given without time constraints with emphasis on precision. The resulting estimates are used as baseline to evaluate horizon estimates from early visual processes. Stimuli are presented for only ms and then masked to purge visual short-term memory and enforcing estimates to rely on early processes, only. The high agreement between estimates and the lack of a training effect shows that enough information about viewpoint is extracted in the first few hundred milliseconds to make accurate horizon estimation possible. In Experiment 3 we investigate several strategies to estimate the horizon in the computer and compare human with machine “behavior” for different image manipulations and image scene types. PMID:24349073

  20. Spherically Symmetric Trapping Horizons, the Misner-Sharp Mass and Black Hole Evaporation

    NASA Astrophysics Data System (ADS)

    Nielsen, Alex B.; Yeom, Dong-Han

    We discuss some of the issues relating to information loss and black hole thermodynamics in the light of recent work on local black hole horizons. Understood in terms of pure states evolving into mixed states, the possibility of information loss in black holes is closely related to the global causal structure of space-time, as is the existence of event horizons. However, black holes need not be defined by event horizons, and in fact we argue that in order to have a fully unitary evolution for black holes, they should be defined in terms of something else, such as a trapping horizon. The Misner-Sharp mass in spherical symmetry shows very simply how trapping horizons can give rise to black hole thermodynamics, Hawking radiation and singularities. We show how the Misner-Sharp mass can also be used to give insights into the process of collapse and evaporation of locally defined black holes.

  1. Gravitational black hole hair from event horizon supertranslations

    NASA Astrophysics Data System (ADS)

    Averin, Artem; Dvali, Gia; Gomez, Cesar; Lüst, Dieter

    2016-06-01

    We discuss BMS supertranslations both at null-infinity BMS- and on the horizon {BMS}^{mathscr{H}} for the case of the Schwarzschild black hole. We show that both kinds of supertranslations lead to infinetly many gapless physical excitations. On this basis we construct a quotient algebra mathcal{A}equiv {BMS}^{mathscr{H}}/{BMS}- using suited superpositions of both kinds of transformations which cannot be compensated by an ordinary BMS-supertranslation and therefore are intrinsically due to the presence of an event horizon. We show that transformations in mathcal{A} are physical and generate gapless excitations on the horizon that can account for the gravitational hair as well as for the black hole entropy. We identify the physics of these modes as associated with Bogolioubov-Goldstone modes due to quantum criticality. Classically the number of these gapless modes is infinite. However, we show that due to quantum criticality the actual amount of information-carriers becomes finite and consistent with Bekenstein entropy. Although we only consider the case of Schwarzschild geometry, the arguments are extendable to arbitrary space-times containing event horizons.

  2. New Horizons' Extreme Close-Up of Pluto’s Surface (no audio)

    NASA Video Gallery

    This is the most detailed view of Pluto’s terrain you’ll see for a very long time. This mosaic strip – extending across the hemisphere that faced the New Horizons spacecraft as it flew past Pluto o...

  3. Sexual function 1-year after allogeneic hematopoietic stem cell transplantation.

    PubMed

    Noerskov, K H; Schjødt, I; Syrjala, K L; Jarden, M

    2016-06-01

    Treatment with allogeneic hematopoietic stem cell transplantation (HSCT) is associated with short and long-term toxicities that can result in alterations in sexual functioning. The aims of this prospective evaluation were to determine: (1) associations between HSCT and increased sexual dysfunction 1 year after treatment; and (2) associations between sexual dysfunction, body image, anxiety and depression. This controlled prospective cohort study was conducted from October 2010 to November 2013. Patients completed assessments 2-3 weeks before HSCT (N=124) and 1 year after treatment (N=63). Assessment included descriptive data, Sexual Functioning Questionnaire, Body Image Scale and Hospital Anxiety and Depression Scale. The results showed a significant decline in overall sexual function in both men and women (P=<0.001, P=0.010, respectively), although men generally scored higher than women. Forty-seven percent of men and 60% of women reported at least one physical sexual problem 1 year after HSCT. Patients with chronic GVHD trended toward reporting lower levels of sexual function. Finally, women with chronic GVHD scored lower than those without chronic GVHD on the sexual function problem subscale (P=0.008). Sexual dysfunction remains a major problem for men and women 1 year after HSCT and requires routine evaluation and treatment after HSCT. PMID:26878660

  4. Anxiety Sensitivity and Panic Attacks: A 1-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Li, Wen; Zinbarg, Richard E.

    2007-01-01

    The hypothesis that anxiety sensitivity (AS) is a risk factor for panic genesis has obtained compelling support, but the clinical/practical importance of AS in panic genesis has been questioned. In addition, the association between panic experience and AS increase has not been clearly demonstrated. Through this 1-year longitudinal study among…

  5. Quasilocal approach to general universal horizons

    NASA Astrophysics Data System (ADS)

    Maciel, Alan

    2016-05-01

    Theories of gravity with a preferred foliation usually display arbitrarily fast signal propagation, changing the black hole definition. A new inescapable barrier, the universal horizon, has been defined and many static and spherically symmetric examples have been studied in the literature. Here, we translate the usual definition of the universal horizon in terms of an optical scalar built with the preferred flow defined by the preferred spacetime foliation. The new expression has the advantages of being of quasilocal nature and independent of specific spacetime symmetries in order to be well defined. Therefore, we propose it as a definition for general quasilocal universal horizons. Using the new formalism, we show that there is no universal analog of cosmological horizons for Friedmann-Lemaître-Robertson-Walker models for any scale factor function, and we also state that quasilocal universal horizons are restricted to trapped regions of the spacetime. Using the evolution equation, we analyze the formation of universal horizons under a truncated Hořava-Lifshitz theory, in spherical symmetry, showing the existence of regions in parameter space where the universal horizon formation cannot be smooth from the center, under some physically reasonable assumptions. We conclude with our view on the next steps for the understanding of black holes in nonrelativistic gravity theories.

  6. A concrete anti-de Sitter black hole with dynamical horizon having toroidal cross-sections and its characteristics

    NASA Astrophysics Data System (ADS)

    Dadras, Pouria; Firouzjaee, J. T.; Mansouri, Reza

    2012-11-01

    We propose a special solution of Einstein equations in the general Vaidya form representing a dynamical black hole having horizon cross-sections with toroidal topology. The concrete model enables us to study for the first time dynamical horizons with toroidal topology, its area law, and the question of matter flux inside the horizon, without using a cut-and-paste technology to construct the solution.

  7. Production and decay of evolving horizons

    NASA Astrophysics Data System (ADS)

    Nielsen, Alex B.; Visser, Matt

    2006-07-01

    We consider a simple physical model for an evolving horizon that is strongly interacting with its environment, exchanging arbitrarily large quantities of matter with its environment in the form of both infalling material and outgoing Hawking radiation. We permit fluxes of both lightlike and timelike particles to cross the horizon, and ask how the horizon grows and shrinks in response to such flows. We place a premium on providing a clear and straightforward exposition with simple formulae. To be able to handle such a highly dynamical situation in a simple manner we make one significant physical restriction—that of spherical symmetry—and two technical mathematical restrictions: (1) we choose to slice the spacetime in such a way that the spacetime foliations (and hence the horizons) are always spherically symmetric. (2) Furthermore, we adopt Painlevé Gullstrand coordinates (which are well suited to the problem because they are nonsingular at the horizon) in order to simplify the relevant calculations. Of course physics results are ultimately independent of the choice of coordinates, but this particular coordinate system yields a clean physical interpretation of the relevant physics. We find particularly simple forms for surface gravity, and for the first and second law of black hole thermodynamics, in this general evolving horizon situation. Furthermore, we relate our results to Hawking's apparent horizon, Ashtekar and co-worker's isolated and dynamical horizons, and Hayward's trapping horizon. The evolving black hole model discussed here will be of interest, both from an astrophysical viewpoint in terms of discussing growing black holes and from a purely theoretical viewpoint in discussing black hole evaporation via Hawking radiation.

  8. New Horizons: Bridge to the Beginning - to Pluto and Beyond

    NASA Astrophysics Data System (ADS)

    Weir, H. M.; Hallau, K. G.; Seaton, P.; Beisser, K.; New Horizons Education; Public Outreach Team

    2010-12-01

    Launched on Jan. 19, 2006, NASA’s New Horizons mission to Pluto and the Kuiper Belt will help us understand worlds at the edge of our solar system by making the first reconnaissance of Pluto and Charon - a "double planet" and the last planet in our solar system to be visited by spacecraft. However, New Horizons’ closest approach to Pluto will not occur until July 14, 2015, and the majority of the craft's time over the next 5 years will be spent in "hibernation." The Education and Public Outreach (EPO) team, however, will not be hibernating as we wait for New Horizons to reach its destination. With three distinct tools-- Educator Fellows, online learning modules and a planetarium program--the team seeks to excite and engage teachers, students and the public with information about the journey to Pluto and beyond. In the past year, the specially selected educators who participate as New Horizons Educator Fellows have trained more than 1,000 teachers across the U.S. on the New Horizons mission and the science behind it. Thousands more students, parents, educators, and citizens have learned about New Horizons from the mission's scientists, engineers and outreach professionals. New Horizons Fellows also distribute another EPO tool: online learning modules. These classroom-ready learning modules consist of educator guides, student handouts, detailed activities, and potential adaptations for students with special needs or disabilities. Some also offer online interactives to convey complex and dynamic concepts. The modules are web-accessible for both students and teachers, and are aligned with relevant national standards. The third tool is a highly visual way to engage the general public and supplement educational programs: a planetarium program that highlights the New Horizons mission from launch to destination Pluto. This program focuses on the engineering design of the spacecraft, with a focus on the concept of the electromagnetic spectrum. In the unique environment

  9. On the thermodynamics of the cosmological apparent horizon

    NASA Astrophysics Data System (ADS)

    Pollock, M. D.

    2015-11-01

    It has been shown by Cai et al. that the apparent horizon of radius r0 in the cosmological Friedmann space-time emits radiation at the temperature T0 = 1/2π r0. Here, we derive this result from the Wheeler-DeWitt equation for the wave function of the Universe Ψ, starting from a classical gravitational Lagrangian L that contains a quadratic higher-derivative term R2 , the scalar component of which is non-tachyonic, by application of the horizon hypothesis and definition of the physical three-space on the time-slice dx0 = 0. We also extend our previous analysis of the Wheeler-DeWitt equation for the wave function Φ of the apparent horizon of the de Sitter space-time to include the case of a more general energy-momentum source, that generates an arbitrary Friedmann space-time, confirming the expression for T0 after application of the ADM formalism.

  10. Quantum Phase Transitions and Event Horizons:. Condensed Matter Analogies

    NASA Astrophysics Data System (ADS)

    Chapline, George

    2006-07-01

    Although it has been generally believed that classical general relativity is always correct for macroscopic length scales, certain predictions such as event horizons and closed time-like curves are inconsistent with ordinary quantum mechanics. It has recently been pointed out that the event horizon problem can be resolved if space-time undergoes a quantum phase transition as one approaches the surface where general relativity predicts that the redshift becomes infinite. Indeed a thought experiment involving a superfluid with a critical point makes such a suggestion appear plausible. Furthermore the behavior of space-time near an event horizon may resemble quantum phase transitions that have been observed in the laboratory. For example, the phenomenology of meta-magnetic quantum critical points in heavy fermion materials resembles the behavior expected, both in terms of time standing still and the behavior of quantum correlation functions. Martensitic transformations accompanied by non-adiabatic changes in the electronic wave function are also interesting in this connection.

  11. Horizon Entropy from Quantum Gravity Condensates

    NASA Astrophysics Data System (ADS)

    Oriti, Daniele; Pranzetti, Daniele; Sindoni, Lorenzo

    2016-05-01

    We construct condensate states encoding the continuum spherically symmetric quantum geometry of a horizon in full quantum gravity, i.e., without any classical symmetry reduction, in the group field theory formalism. Tracing over the bulk degrees of freedom, we show how the resulting reduced density matrix manifestly exhibits a holographic behavior. We derive a complete orthonormal basis of eigenstates for the reduced density matrix of the horizon and use it to compute the horizon entanglement entropy. By imposing consistency with the horizon boundary conditions and semiclassical thermodynamical properties, we recover the Bekenstein-Hawking entropy formula for any value of the Immirzi parameter. Our analysis supports the equivalence between the von Neumann (entanglement) entropy interpretation and the Boltzmann (statistical) one.

  12. Horizon Entropy from Quantum Gravity Condensates.

    PubMed

    Oriti, Daniele; Pranzetti, Daniele; Sindoni, Lorenzo

    2016-05-27

    We construct condensate states encoding the continuum spherically symmetric quantum geometry of a horizon in full quantum gravity, i.e., without any classical symmetry reduction, in the group field theory formalism. Tracing over the bulk degrees of freedom, we show how the resulting reduced density matrix manifestly exhibits a holographic behavior. We derive a complete orthonormal basis of eigenstates for the reduced density matrix of the horizon and use it to compute the horizon entanglement entropy. By imposing consistency with the horizon boundary conditions and semiclassical thermodynamical properties, we recover the Bekenstein-Hawking entropy formula for any value of the Immirzi parameter. Our analysis supports the equivalence between the von Neumann (entanglement) entropy interpretation and the Boltzmann (statistical) one. PMID:27284642

  13. Information Horizons in Complex Networks

    NASA Astrophysics Data System (ADS)

    Sneppen, Kim

    2005-03-01

    We investigate how the structure constrain specific communication in social-, man-made and biological networks. We find that human networks of governance and collaboration are predictable on teat-a-teat level, reflecting well defined pathways, but globally inefficient (1). In contrast, the Internet tends to have better overall communication abilities, more alternative pathways, and is therefore more robust. Between these extremes are the molecular network of living organisms. Further, for most real world networks we find that communication ability is favored by topology on small distances, but disfavored at larger distances (2,3,4). We discuss the topological implications in terms of modularity and the positioning of hubs in the networks (5,6). Finally we introduce some simple models which demonstarte how communication may shape the structure of in particular man made networks (7,8). 1) K. Sneppen, A. Trusina, M. Rosvall (2004). Hide and seek on complex networks [cond-mat/0407055] 2) M. Rosvall, A. Trusina, P. Minnhagen and K. Sneppen (2004). Networks and Cities: An Information Perspective [cond-mat/0407054]. In PRL. 3) A. Trusina, M. Rosvall, K. Sneppen (2004). Information Horizons in Networks. [cond-mat/0412064] 4) M. Rosvall, P. Minnhagen, K. Sneppen (2004). Navigating Networks with Limited Information. [cond-mat/0412051] 5) S. Maslov and K. Sneppen (2002). Specificity and stability in topology of protein networks Science 296, 910-913 [cond-mat/0205380]. 6) A. Trusina, S. Maslov, P. Minnhagen, K. Sneppen Hierarchy Measures in Complex Networks. Phys. Rev. Lett. 92, 178702 [cond-mat/0308339]. 7) M. Rosvall and K. Sneppen (2003). Modeling Dynamics of Information Networks. Phys. Rev. Lett. 91, 178701 [cond-mat/0308399]. 8) B-J. Kim, A. Trusina, P. Minnhagen, K. Sneppen (2003). Self Organized Scale-Free Networks from Merging and Regeneration. nlin.AO/0403006. In European Journal of Physics.

  14. A Program To Promote Positive Body Image: A 1-Year Follow-Up Evaluation.

    ERIC Educational Resources Information Center

    McVey, Gail L.; Davis, Ron

    2002-01-01

    Evaluated the effectiveness of a program designed to promote body image satisfaction and prevent eating problems in young adolescent girls over a 1-year period. Found no program effect. Found instead, significant increases in body image satisfaction and decreases in eating problem scores over time for participants in both the prevention and…

  15. Secondary preventive medication persistence and adherence 1 year after stroke

    PubMed Central

    Olson, D.M.; Zhao, X.; Pan, W.; Zimmer, L.O.; Goldstein, L.B.; Alberts, M.J.; Fagan, S.C.; Fonarow, G.C.; Johnston, S.C.; Kidwell, C.; LaBresh, K.A.; Ovbiagele, B.; Schwamm, L.; Peterson, E.D.

    2011-01-01

    Objective: Data on long-term use of secondary prevention medications following stroke are limited. The Adherence eValuation After Ischemic stroke–Longitudinal (AVAIL) Registry assessed patient, provider, and system-level factors influencing continuation of prevention medications for 1 year following stroke hospitalization discharge. Methods: Patients with ischemic stroke or TIA discharged from 106 hospitals participating in the American Heart Association Get With The Guidelines–Stroke program were surveyed to determine their use of warfarin, antiplatelet, antihypertensive, lipid-lowering, and diabetes medications from discharge to 12 months. Reasons for stopping medications were ascertained. Persistence was defined as continuation of all secondary preventive medications prescribed at hospital discharge, and adherence as continuation of prescribed medications except those stopped according to health care provider instructions. Results: Of the 2,880 patients enrolled in AVAIL, 88.4% (2,457 patients) completed 1-year interviews. Of these, 65.9% were regimen persistent and 86.6% were regimen adherent. Independent predictors of 1-year medication persistence included fewer medications prescribed at discharge, having an adequate income, having an appointment with a primary care provider, and greater understanding of why medications were prescribed and their side effects. Independent predictors of adherence were similar to those for persistence. Conclusions: Although up to one-third of stroke patients discontinued one or more secondary prevention medications within 1 year of hospital discharge, self-discontinuation of these medications is uncommon. Several potentially modifiable patient, provider, and system-level factors associated with persistence and adherence may be targets for future interventions. PMID:21900638

  16. Time of flight secondary ion mass spectrometry and high-resolution transmission electron microscopy/energy dispersive spectroscopy: a preliminary study of the distribution of Cu2+ and Cu2+/Pb2+ on a Bt horizon surfaces.

    PubMed

    Cerqueira, B; Vega, F A; Serra, C; Silva, L F O; Andrade, M L

    2011-11-15

    Relatively new techniques can help in determining the occurrence of mineral species and the distribution of contaminants on soil surfaces such as natural minerals and organic matter. The Bt horizon from an Endoleptic Luvisol was chosen because of its well-known sorption capability. The samples were contaminated with Cu(2+) and/or Pb(2+) and both sorption and desorption experiments were performed. The preferential distribution of the contaminant species ((63)Cu and (208)Pb) to the main soil components and their associations were studied together with the effectiveness of the surface sorption and desorption processes. The results obtained were compared with non-contaminated samples as well as with previous results obtained by different analytical techniques and advanced statistical analysis. Pb(2+) competes favorably for the sorption sites in this soil, mainly in oxides and the clay fraction. Cu(2+) and Pb(2+) were mainly associated with hematite, gibbsite, vermiculite and chlorite. This study will serve as a basis for further scientific research on the soil retention of heavy metals. New techniques such as spectroscopic imaging and transmission electron microscopy make it possible to check which soil components retain heavy metals, thereby contributing to propose effective measures for the remediation of contaminated soil. PMID:21920666

  17. Clinical differences between opioid abuse classes ameliorated after 1 year of buprenorphine-medication assisted treatment.

    PubMed

    Tkacz, Joseph; Severt, Jamie; Kassed, Cheryl; Ruetsch, Charles

    2012-01-01

    This study compared the clinical and demographic profiles of three opioid-dependent user groups, and measured their response to 1 year of buprenorphine-medication assisted treatment. Opioid prescription, street, and combination (street + prescription) users completed the Addiction Severity Index multiple times over the course of one treatment year. Although groups differed on all measured demographics (P values <.05) and on six of seven Addiction Severity Index composite scores at induction (P values <.05), differences were ameliorated after 1 year. Findings highlight the disparities between the various opioid-dependent patient subpopulations and suggest that buprenorphine-medication assisted treatment is an effective treatment across user subtypes. PMID:22540432

  18. Pluto Time

    NASA Video Gallery

    If you stood on Pluto at noon and looked around, the landscape would be illuminated about as brightly as on Earth soon after sunset. The team for NASA's New Horizons mission dubbed this "Pluto Time...

  19. Possible New Horizons Fundamental Contribution to Cosmology

    NASA Astrophysics Data System (ADS)

    Conn Henry, Richard; Murthy, Jayant

    2016-01-01

    The New Horizons (NH) spacecraft (S. Alan Stern, PI) is now past Pluto, and in our poster we explore the possibility of making observations, using the NH P-Alice ultraviolet spectrometer, of the cosmic diffuse ultraviolet background radiation, particularily at high northern and southern Galactic latitudes. In the paper, "The Mystery of the Cosmic Diffuse Ultraviolet Background Radiation," by Richard Conn Henry, Jayant Murthy, James Overduin, Joshua Tyler, ApJ, 798:14 (25pp), 2015 January 1, we demonstrated the existence of a second component of the diffuse far ultraviolet background radiation beyond that provided by dust-scattered starlight. The critical question is, does that second component (of unknown origin) extend shortward of the Lyman limit of 912 Å? If it does, then it seems likely that we have discovered the source of the reionization of the Universe that occurred some time after recombination. As things stand at the moment, there is no known source that has been demonstrated to be capable of performing the reionization: reionization that clearly did occur. Our current understanding of P-Alice suggests that it may well be capable of demonstrating the presence (or absence) of such ionizing cosmic diffuse radiation. At low Galactic latitudes, all such radiation would be totally erased by the presence, in large quantities, of interstellar neutral hydrogen; this will allow us to test the reality of any such flux that we may discover at higher Galactic latitudes.

  20. Possible Evidence for an Event Horizon in Cyg XR-1

    NASA Technical Reports Server (NTRS)

    Dolan, Joseph F.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    The X-ray emitting component in the Cyg XR-1/HDE226868 system is a leading candidate for identification as a stellar-mass sized black hole. The positive identification of a black hole as predicted by general relativity requires the detection of an event horizon surrounding the point singularity. One signature of such an event horizon would be the existence of dying pulse trains emitted by material spiraling into the event horizon from the last stable orbit around the black hole. We observed the Cyg XR-1 system at three different epochs in a 1400 - 3000 A bandpass with 0.1 ms time resolution using the Hubble Space Telescope's High Speed Photometer. Repeated excursions of the detected flux by more than three standard deviations above the mean are present in the UV flux with FWHM 1 - 10 ms. If any of these excursions are pulses of radiation produced in the system (and not just stochastic variability associated with the Poisson distribution of detected photon arrival times), then this short a timescale requires that the pulses originate in the accretion disk around Cyg XR-1. Two series of pulses with characteristics similar to those expected from dying pulse trains were detected in three hours of observation.

  1. Investment horizon heterogeneity and wavelet: Overview and further research directions

    NASA Astrophysics Data System (ADS)

    Chakrabarty, Anindya; De, Anupam; Gunasekaran, Angappa; Dubey, Rameshwar

    2015-07-01

    Wavelet based multi-scale analysis of financial time series has attracted much attention, lately, from both the academia and practitioners from all around the world. The unceasing metamorphosis of the discipline of finance from its humble beginning as applied economics to the more sophisticated depiction as applied physics and applied psychology has revolutionized the way we perceive the market and its complexities. One such complexity is the presence of heterogeneous horizon agents in the market. In this context, we have performed a generous review of different aspects of horizon heterogeneity that has been successfully elucidated through the synergy between wavelet theory and finance. The evolution of wavelet has been succinctly delineated to bestow necessary information to the readers who are new to this field. The migration of wavelet into finance and its subsequent branching into different sub-divisions have been sketched. The pertinent literature on the impact of horizon heterogeneity on risk, asset pricing and inter-dependencies of the financial time series are explored. The significant contributions are collated and classified in accordance to their purpose and approach so that potential researcher and practitioners, interested in this subject, can be benefited. Future research possibilities in the direction of "agency cost mitigation" and "synergy between econophysics and behavioral finance in stock market forecasting" are also suggested in the paper.

  2. The Astrophysical Signatures of Black Holes: The Horizon, The ISCO, The Ergosphere and The Light Circle

    NASA Astrophysics Data System (ADS)

    Abramowicz, Marek A.

    Three advanced instruments planned for a near future ( LOFT, GRAVITY, THE EVENT HORIZON TELESCOPE) provide unprecedented angular and time resolutions, which allow to probe regions in the immediate vicinity of black holes. We may soon be able to search for the signatures of the super-strong gravity that is characteristic to black holes: the event horizon, the ergosphere, the innermost stable circular orbit (ISCO), and the photon circle. This review discusses a few fundamental problems concerning these theoretical concepts.

  3. The New Horizons Mission to Pluto and the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Weaver, H. A.; Stern, S. A.; New Horizons Science; Engineering Team

    New Horizons, which initiates the NASA New Frontiers program of mid-sized missions, will provide the first scientific reconnaissance of the Pluto-Charon system and is scheduled for launch in January 2006. An encounter with Jupiter at a flyby distance of ˜32-45 RJ about 13 months after launch provides a gravity boost for the spacecraft's journey to Pluto and practice for the Pluto encounter, in addition to providing an opportunity to perform a valuable set of scientific measurements within the jovian system. New Horizons carries a sophisticated suite of instruments to perform ultraviolet and infrared spectroscopy, panchromatic and color optical imaging, and charged particle and dust measurements, all within a spacecraft having a total mass of ˜465 kg and total power output of ˜210 W at the time of Pluto encounter in July 2015. The primary scientific objectives of the New Horizons are to characterize the global geology and morphology of Pluto and Charon, map the surface composition of Pluto and Charon, and characterize the neutral atmosphere and its escape rate, but many other important scientific objectives will be addressed as well. New Horizons has the capability to image Pluto with a resolution exceeding that provided by the Hubble Space Telescope for at least 90 days prior to closest approach at a distance of ˜10,000 km from the surface, at which time a resolution of ˜100 m will be achieved for selected regions near the terminator. After encounter, the spacecraft will pass through the shadows of both Pluto and Charon, which enables radio and ultraviolet occultation measurements of their atmospheres. If an extended mission phase is approved, the spacecraft will be re-targeted to encounter one or more Kuiper belt objects (KBOs), roughly 3 years after the Pluto encounter at a heliocentric distance of ˜42 AU. The scientific objectives for the KBO encounters are similar to those for the Pluto encounter.

  4. Aluminum solubility control in different horizons of a podzol

    SciTech Connect

    Zysset, M.; Blaser, P.; Luster, J.; Gehring, A.U.

    1999-10-01

    In the last two decades, the anthropogenically induced acceleration of forest soil acidification has been a topic of environmental concern. Aluminum extractability and solubility were investigated in detail in six horizons of a Typic Haplohumod (FAO:Haplic Podzol) from southern Switzerland. Pyrophosphate and oxalate extractions as well as successive acid leaching indicated that in the Ah, (AE), and Bh horizons reactive Al is mainly bound to soil organic matter, whereas in the Bs, BC1, and BC2 horizons it is of inorganic nature. In the latter three horizons, infrared (IR) spectroscopy and transmission electron microscopy (TEM) revealed the presence of imogolite. Batch equilibrium experiments at 20 C in the pH range of approximately 3.5 to 5.5 showed that the podzol profile can be divided into two parts of different Al solubility control. In the Ah and (AE) horizons, Al solubility was found to be controlled by complexation reactions to soil organic matter. Kinetic studies with samples of the Bh, Bs, BC1, and BC2 horizons showed that ion activity products with respect to both Al(OH){sub 3} and imogolite, (HO){sub 3}Al{sub 2}O{sub 3}SiOH, reached a constant value after reaction times of 16 d. For pH {gt}4.1, the compilation of all data revealed pAl + 0.5 pSi = 3.05 pH {minus} 7.04 (r{sup 2} = 0.99) and pAl = 2.87 pH {minus} 8.07 (r{sup 2} = 0.99). These data could be shown to be consistent with either Al solubility control by imogolite-type material (ITM) with a log *K{sub s}{sup 0} = 6.53 {+-} 0.09, which dissolves incongruently, or a simultaneous equilibrium with ITM and hydroxy-Al interlayers of clay minerals. For pH {lt} 4.1, data indicated solubility control by a 1:1 aluminosilicate, e.g., poorly crystalline kaolinite.

  5. Microbial community successional patterns in beach sands impacted by the Deepwater Horizon oil spill.

    PubMed

    Rodriguez-R, Luis M; Overholt, Will A; Hagan, Christopher; Huettel, Markus; Kostka, Joel E; Konstantinidis, Konstantinos T

    2015-09-01

    Although petroleum hydrocarbons discharged from the Deepwater Horizon (DWH) blowout were shown to have a pronounced impact on indigenous microbial communities in the Gulf of Mexico, effects on nearshore or coastal ecosystems remain understudied. This study investigated the successional patterns of functional and taxonomic diversity for over 1 year after the DWH oil was deposited on Pensacola Beach sands (FL, USA), using metagenomic and 16S rRNA gene amplicon techniques. Gamma- and Alphaproteobacteria were enriched in oiled sediments, in corroboration of previous studies. In contrast to previous studies, we observed an increase in the functional diversity of the community in response to oil contamination and a functional transition from generalist populations within 4 months after oil came ashore to specialists a year later, when oil was undetectable. At the latter time point, a typical beach community had reestablished that showed little to no evidence of oil hydrocarbon degradation potential, was enriched in archaeal taxa known to be sensitive to xenobiotics, but differed significantly from the community before the oil spill. Further, a clear succession pattern was observed, where early responders to oil contamination, likely degrading aliphatic hydrocarbons, were replaced after 3 months by populations capable of aromatic hydrocarbon decomposition. Collectively, our results advance the understanding of how natural benthic microbial communities respond to crude oil perturbation, supporting the specialization-disturbance hypothesis; that is, the expectation that disturbance favors generalists, while providing (microbial) indicator species and genes for the chemical evolution of oil hydrocarbons during degradation and weathering. PMID:25689026

  6. Participation as a leader in immersion weight loss treatment: a 1-year follow-up study.

    PubMed

    Anderson, L M; Schaumberg, K; Anderson, D A; Kirschenbaum, D S

    2016-02-01

    Non-overweight individuals may follow aggressive weight management approaches alongside overweight/obese friends or family members; thus, research has begun to evaluate subsequent effects among non-overweight populations. A prior study evaluated the short-term effects of an immersion weight loss programme on healthy young adult staff leaders. Results indicated that participation seemed to benefit, not harm, the young adults. The current investigation examined 1-year eating disorder and weight trajectories in this sample. The total sample (N = 244) consisted of staff leaders (44.3%) and demographically similar comparison participants who completed eating disorder and weight assessments across four time points: baseline, end of summer, 6-week follow-up and 1-year follow-up. Forty-seven per cent of the original sample responded to all time points (staff leaders n = 60; comparison n = 55). Over the course of 1 year, risk trajectories did not differ between groups. Staff leaders did not report significant changes in body mass index, suggesting that they maintained healthy weight over the course of 1 year. Participation as an immersion weight loss programme leader appeared to be protective against weight gain, without increasing eating disorder risk, for healthy young adults. This provides further support for using weight management interventions across a wide range of individuals. PMID:26638779

  7. Star-Paths, Stones and Horizon Astronomy

    NASA Astrophysics Data System (ADS)

    Brady, Bernadette

    2015-05-01

    Archaeoastronomers tend to approach ancient monuments focusing on the landscape and the horizon calendar events of sun and moon and, due to problems with precession, generally ignore the movement of the stars. However, locating the position of solar calendar points on the horizon can have other uses apart from calendar and/or cosmological purposes. This paper firstly suggests that the stars do not need to be ignored. By considering the evidence of the Phaenomena, a sky poem by Aratus of Soli, a third century BC Greek poet, and his use of second millennium BC star lore fragments, this paper argues that the stars were a part of the knowledge of horizon astronomy. Aratus' poem implied that the horizon astronomy of the late Neolithic and Bronze Age periods included knowledge of star-paths or 'linear constellations' that were defined by particular horizon calendar events and other azimuths. Knowledge of such star-paths would have enabled navigation and orientation, and by using permanent markers, constructed or natural, to define these paths, they were immune to precession as the stones could redefine a star-path for a future generation. Finally the paper presents other possible intentions behind the diverse orientation of passage tombs and some megalithic sites.

  8. Flying by Ear: Blind Flight with a Music-Based Artificial Horizon

    NASA Technical Reports Server (NTRS)

    Simpson, Brian D.; Brungart, Douglas S.; Dallman, Ronald C.; Yasky, Richard J., Jr.; Romigh, Griffin

    2008-01-01

    Two experiments were conducted in actual flight operations to evaluate an audio artificial horizon display that imposed aircraft attitude information on pilot-selected music. The first experiment examined a pilot's ability to identify, with vision obscured, a change in aircraft roll or pitch, with and without the audio artificial horizon display. The results suggest that the audio horizon display improves the accuracy of attitude identification overall, but differentially affects response time across conditions. In the second experiment, subject pilots performed recoveries from displaced aircraft attitudes using either standard visual instruments, or, with vision obscured, the audio artificial horizon display. The results suggest that subjects were able to maneuver the aircraft to within its safety envelope. Overall, pilots were able to benefit from the display, suggesting that such a display could help to improve overall safety in general aviation.

  9. The Event Horizon Telescope: New Developments and Results

    NASA Astrophysics Data System (ADS)

    Johnson, Michael D.; Doeleman, Sheperd S.; Event Horizon Telescope Collaboration

    2015-08-01

    A convergence of high-bandwidth radio instrumentation and global submillimeter facilities is enabling assembly of the Event Horizon Telescope (EHT): a short-wavelength Very-Long-Baseline Interferometry array capable of observing the nearest supermassive black holes with Schwarzschild-radius resolution. Initial observations with the EHT have revealed event-horizon-scale structure in Sgr A*, the 4 million solar mass black hole at the Galactic center, and in the much more luminous and massive black hole at the center of the giant elliptical galaxy M87. The past year has witnessed rapid expansion of the array, including first light and successful interferometric fringes for new receivers at the Large Millimeter Telescope in Mexico and the South Pole Telescope, as well as fringes to the ALMA phased array. Concurrent instrumental developments also allow 2 GHz observing bandwidth with dual polarization in the 2015 observing campaign. Together, these advances will yield an unprecedented combination of sensitivity and resolution, with excellent prospects for imaging strong general relativistic signatures, detecting horizon-scale magnetic field structures through full polarization observations, and time-resolving dynamical activity near a black hole. I will briefly review the recent developments and technical timeline for completing the EHT and will present new results from our 2013 observing campaign.

  10. The Orbits and Masses of Pluto's Satellites after New Horizons

    NASA Astrophysics Data System (ADS)

    Jacobson, Robert A.; Brozovic, Marina; Buie, Marc; Porter, Simon; Showalter, Mark; Spencer, John; Stern, S. Alan; Weaver, Harold; Young, Leslie; Ennico, Kimberly; Olkin, Cathy

    2015-11-01

    Brozović et al. (2015 Icarus 246, 317) reported on Pluto's mass and the masses and numerically integrated orbits of Pluto's satellites, Charon, Nix, Hydra, Kerberos, and Styx. These were determined via a fit to an extensive set of astrometric, mutual event, and stellar occultation observations over the time interval April 1965 to July 2012. The data set contained the Hubble Space Telescope (HST) observations of Charon relative to Pluto that were corrected for the Pluto center-of-figure center-of-light offset due to the Pluto albedo variations (Buie et al. 2012 AJ 144, 15). Also included were all of the available HST observations of Nix, Hydra, Kerberos, and Styx. For the New Horizons encounter with the Pluto system, the initial satellite ephemerides (PLU043) and the initial planet and satellite masses were taken from the Brozović et al. analysis. During the New Horizons approach, the ephemerides and masses were periodically updated along with the spacecraft trajectory by the New Horizons navigation team using imaging of the planet and satellites against the stellar background. In this work, we report on our post-flyby analysis of the masses and satellite orbits derived from a combination of the original PLU043 data set, the New Horizions imaging data, and HST observations acquired after 2012.

  11. On horizons and wormholes in k-essence theories

    NASA Astrophysics Data System (ADS)

    Bronnikov, K. A.; Fabris, J. C.; Rodrigues, Denis C.

    2016-01-01

    We study the properties of possible static, spherically symmetric configurations in k-essence theories with the Lagrangian functions of the form $F(X)$, $X \\equiv \\phi_{,\\alpha} \\phi^{,\\alpha}$. A no-go theorem has been proved, claiming that a possible black-hole-like Killing horizon of finite radius cannot exist if the function $F(X)$ is required to have a finite derivative $dF/dX$. Two exact solutions are obtained for special cases of k-essence: one for $F(X) =F_0 X^{1/3}$, another for $F(X) = F_0 |X|^{1/2} - 2 \\Lambda$, where $F_0$ and $\\Lambda$ are constants. Both solutions contain horizons, are not asymptotically flat, and provide illustrations for the obtained no-go theorem. The first solution may be interpreted as describing a black hole in an asymptotically singular space-time, while in the second solution two horizons of infinite area are connected by a wormhole.

  12. Summary and status of the Horizons ephemeris system

    NASA Astrophysics Data System (ADS)

    Giorgini, J.

    2011-10-01

    Since 1996, the Horizons system has provided searchable access to JPL ephemerides for all known solar system bodies, several dozen spacecraft, planetary system barycenters, and some libration points. Responding to 18 400 000 requests from 300 000 unique addresses, the system has recently averaged 420 000 ephemeris requests per month. Horizons is accessed and automated using three interfaces: interactive telnet, web-browser form, and e-mail command-file. Asteroid and comet ephemerides are numerically integrated from JPL's database of initial conditions. This small-body database is updated hourly by a separate process as new measurements and discoveries are reported by the Minor Planet Center and automatically incorporated into new JPL orbit solutions. Ephemerides for other objects are derived by interpolating previously developed solutions whose trajectories have been represented in a file. For asteroids and comets, such files may be dynamically created and transferred to users, effectively recording integrator output. These small-body SPK files may then be interpolated by user software to reproduce the trajectory without duplicating the numerically integrated n-body dynamical model or PPN equations of motion. Other Horizons output is numerical and in the form of plain-text observer, vector, osculating element, or close-approach tables, typically expected be read by other software as input. About one hundred quantities can be requested in various time-scales and coordinate systems. For JPL small-body solutions, this includes statistical uncertainties derived from measurement covariance and state transition matrices. With the exception of some natural satellites, Horizons is consistent with DE405/DE406, the IAU 1976 constants, ITRF93, and IAU2009 rotational models.

  13. Holography of 3D flat cosmological horizons.

    PubMed

    Bagchi, Arjun; Detournay, Stéphane; Fareghbal, Reza; Simón, Joan

    2013-04-01

    We provide a first derivation of the Bekenstein-Hawking entropy of 3D flat cosmological horizons in terms of the counting of states in a dual field theory. These horizons appear in the flat limit of nonextremal rotating Banados-Teitleboim-Zanelli black holes and are remnants of the inner horizons. They also satisfy the first law of thermodynamics. We study flat holography as a limit of AdS(3)/CFT(2) to semiclassically compute the density of states in the dual theory, which is given by a contraction of a 2D conformal field theory, exactly reproducing the bulk entropy in the limit of large charges. We comment on how the dual theory reproduces the bulk first law and how cosmological bulk excitations are matched with boundary quantum numbers. PMID:25166977

  14. Otitis media with effusion in children younger than 1 year

    PubMed Central

    Di Francesco, Renata Cantisani; Barros, Vivian Boschesi; Ramos, Rafael

    2016-01-01

    Abstract Objective: To determine the prevalence of otitis media with effusion in children younger than 1 year and its association with the season of the year, artificial feeding, environmental and perinatal factors. Methods: Retrospective study of 184 randomly included medical records from a total of 982 healthy infants evaluated for hearing screening tests. Diagnosis of otitis media with effusion was based on otoscopy (amber-gold color, fluid level, handle of malleus position), type B tympanometric curves and absence of otoacoustic emissions. Incomplete medical records or those describing acute otitis media, upper respiratory tract infections on the assessment day or in the last 3 months, neuropathies and craniofacial anomalies were excluded. Data such as gestational age, birth weight, Apgar score, type of feeding and day care attendance were compared between children with and without otitis media with effusion through likelihood tests and multivariate analysis. Results: 25.3% of 184 infants had otitis media with bilateral effusion; 9.2% had unilateral. In infants with otitis media, the following were observed: chronological age of 9.6±1.7 months; gestational age >38 weeks in 43.4% and birth weight >2500g in 48.4%. Otitis media with effusion was associated with winter/fall, artificial feeding, Apgar score <7 and day care attendance. The multivariate analysis showed that artificial feeding is the factor most often associated to otitis media with effusion. Conclusions: Otitis media with effusion was found in about one third of children younger than 1 year and was mainly associated with artificial feeding. PMID:26559603

  15. East Rim of Endeavour Crater on Horizon

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site]

    A high point on the distant eastern rim of Endeavour Crater is visible on the horizon in this image taken by the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity on March 8, 2009, during the 1,821st Martian day, or sol, of the rover's mission on Mars.

    That portion of Endeavour's rim is about 34 kilometers (21 miles) away from Opportunity's position west of the crater when the image was taken. The width of the image covers approximately one degree of the horizon.

  16. North Rim of Endeavour Crater on Horizon

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site]

    A northern portion of the rim of Endeavour Crater is visible on the horizon of this image taken by the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity on March 7, 2009, during the 1,820st Martian day, or sol, of the rover's mission on Mars.

    That portion of Endeavour's rim is about 20 kilometers (12 miles) away from Opportunity's position west of the crater when the image was taken. The width of the image covers approximately one degree of the horizon.

  17. Expanding your horizons in science and mathematics

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Through the presentation of its Expanding Your Horizons in Science and Mathematics career education conferences for secondary school young women, the Math/Science Network continues its efforts to remove the educational, psychological, and cultural barriers which prevent women from entering math-and science-based careers. The Expanding Your Horizons conferences were presented on 77 college, university and high school campuses across the United States. This year, these unique one day conferences reached 15,500 students, 3,000 parents and educators, and involved 3,000 career women who volunteered their services as conference planners, workshop leaders, speakers, and role models.

  18. Hair-brane ideas on the horizon

    NASA Astrophysics Data System (ADS)

    Martinec, Emil J.; Niehoff, Ben E.

    2015-11-01

    We continue an examination of the microstate geometries program begun in arXiv:1409.6017, focussing on the role of branes that wrap the cycles which degenerate when a throat in the geometry deepens and a horizon forms. An associated quiver quantum mechanical model of minimally wrapped branes exhibits a non-negligible fraction of the gravitational entropy, which scales correctly as a function of the charges. The results suggest a picture of AdS3/CFT2 duality wherein the long string that accounts for BTZ black hole entropy in the CFT description, can also be seen to inhabit the horizon of BPS black holes on the gravity side.

  19. Horizons and plane waves: A review

    SciTech Connect

    Hubeny, Veronika E.; Rangamani, Mukund

    2003-11-06

    We review the attempts to construct black hole/string solutions in asymptotically plane wave spacetimes. First, we demonstrate that geometries admitting a covariantly constant null Killing vector cannot admit event horizons, which implies that pp-waves can't describe black holes. However, relaxing the symmetry requirements allows us to generate solutions which do possess regular event horizons while retaining the requisite asymptotic properties. In particular, we present two solution generating techniques and use them to construct asymptotically plane wave black string/brane geometries.

  20. Evidence for a sedimentary siloxane horizon

    SciTech Connect

    Pellenbarg, R.E.; Tevault, D.E.

    1986-07-01

    Selected samples from two Puget Sound sediment cores have been analyzed for poly(organo)siloxanes(silicones). One core was 60 years old at 30-cm depth (ages by lead-210 dating) and showed no evidence for silicones there. The second, 15 years old at depth, exhibited silicones at depth. Clearly shown is evidence for a siloxane horizon in theses two cores, with the presence of the horizon directly related to the fact that silicones have been in widespread use only since World War II. All samples were analyzed by solvent extraction and diffuse reflectance Fourier transform infrared spectrometry. 10 references, 2 figures, 1 table.

  1. Aerosol physical properties from satellite horizon inversion

    NASA Technical Reports Server (NTRS)

    Gray, C. R.; Malchow, H. L.; Merritt, D. C.; Var, R. E.; Whitney, C. K.

    1973-01-01

    The feasibility is investigated of determining the physical properties of aerosols globally in the altitude region of 10 to 100 km from a satellite horizon scanning experiment. The investigation utilizes a horizon inversion technique previously developed and extended. Aerosol physical properties such as number density, size distribution, and the real and imaginary components of the index of refraction are demonstrated to be invertible in the aerosol size ranges (0.01-0.1 microns), (0.1-1.0 microns), (1.0-10 microns). Extensions of previously developed radiative transfer models and recursive inversion algorithms are displayed.

  2. Hair from the Isolated Horizon Perspective

    NASA Astrophysics Data System (ADS)

    Corichi, A.; Sudarsky, D.

    2002-12-01

    The recently introduced Isolated Horizons (IH) formalism has become a powerful tool for realistic black hole physics. In particular, it generalizes the zeroth and first laws of black hole mechanics in terms of quasi-local quantities and serves as a starting point for quantum entropy calculations. In this note we consider theories which admit hair, and analyze some new results that the IH provides, when considering solitons and stationary solutions. Furthermore, the IH formalism allows to state uniqueness conjectures (i.e. horizon 'no-hair conjectures') for the existence of solutions.

  3. Expanding Horizons of Health Cares

    MedlinePlus

    ... about who uses CAM, how it can alleviate low back pain, how an ancient Chinese treatment works for some ... Progress / Acupuncture From Ancient Practice to Modern Science / Low Back Pain and CAM / Time to Talk / Quiz on Complementary ...

  4. The New Horizons Radio Science Experiment (REX)

    NASA Astrophysics Data System (ADS)

    Tyler, G. L.; Linscott, I. R.; Bird, M. K.; Hinson, D. P.; Strobel, D. F.; Pätzold, M.; Summers, M. E.; Sivaramakrishnan, K.

    2008-10-01

    The New Horizons (NH) Radio Science Experiment, REX, is designed to determine the atmospheric state at the surface of Pluto and in the lowest few scale heights. Expected absolute accuracies in n, p, and T at the surface are 4ṡ1019 m-3, 0.1 Pa, and 3 K, respectively, obtained by radio occultation of a 4.2 cm- λ signal transmitted from Earth at 10-30 kW and received at the NH spacecraft. The threshold for ionospheric observations is roughly 2ṡ109 e- m-3. Radio occultation experiments are planned for both Pluto and Charon, but the level of accuracy for the neutral gas is expected to be useful at Pluto only. REX will also measure the nightside 4.2 cm- λ thermal emission from Pluto and Charon during the time NH is occulted. At Pluto, the thermal scan provides about five half-beams across the disk; at Charon, only disk integrated values can be obtained. A combination of two-way tracking and occultation signals will determine the Pluto system mass to about 0.01 percent, and improve the Pluto-Charon mass ratio. REX flight equipment augments the NH radio transceiver used for spacecraft communications and tracking. Implementation of REX required realization of a new CIC-SCIC signal processing algorithm; the REX hardware implementation requires 1.6 W, and has mass of 160 g in 520 cm3. Commissioning tests conducted after NH launch demonstrate that the REX system is operating as expected.

  5. Contemporaneous Mid-UV Spectral Coverage of Pluto and Charon Coincident With the New Horizons Encounter

    NASA Astrophysics Data System (ADS)

    Schindhelm, Eric

    2014-10-01

    The New Horizons spacecraft will perform the first-ever, and the only planned flyby of the Pluto System, in July 2015. It will observe Pluto and its moons from Far-Ultraviolet (FUV) to radio wavelengths. However, between 1870 and 4200 Angstroms there is no spectral coverage aboard New Horizons. The Mid-Ultraviolet (MUV, 2000 - 3000 Angstroms), which cannot be observed from the ground, contains numerous useful indicators of surface and atmospheric composition that can provide additional constraints about Pluto. Since Pluto's MUV spectrum is known to change over time, it is scientifically important to capture such data at the unique New Horizons encounter epoch. We propose here a focused, 2-orbit STIS G230L observation of Pluto at the same sub-Earth longitude where New Horizons will obtain its best FUV spectra during its closest approach to Pluto. We note that these HST observations need not occur on the same day as the New Horizons encounter, only during the same observing season. In two orbits, STIS yields higher-SNR spectra of Pluto than have ever been obtained to date in the MUV. This will bridge the gap in New Horizons' spectral coverage, placing the FUV spectra in context with longer wavelength data and contributing new information to augment the New Horizons results with those from HST. Our main science objective is MUV spectroscopy of Pluto, however if scheduling allows for the correct roll angle to also capture Charon in the STIS 52"x2" slit, MUV surface reflectance spectra of Charon would also complement New Horizons FUV data.

  6. Spiritual absence and 1-year mortality after hematopoietic stem cell transplant.

    PubMed

    Pereira, Deidre B; Christian, Lisa M; Patidar, Seema; Bishop, Michelle M; Dodd, Stacy M; Athanason, Rebecca; Wingard, John R; Reddy, Vijay S

    2010-08-01

    Religiosity and spirituality have been associated with better survival in large epidemiologic studies. This study examined the relationship between spiritual absence and 1-year all-cause mortality in allogeneic hematopoietic stem cell transplant (HSCT) recipients. Depression and problematic compliance were examined as possible mediators of a significant spiritual absence-mortality relationship. Eighty-five adults (mean = 46.85 years old, SD = 11.90 years) undergoing evaluation for allogeneic HSCT had routine psychologie evaluation prior to HSCT admission. The Millon Behavioral Medicine Diagnostic was used to assess spiritual absence, depression, and problematic compliance, the psychosocial predictors of interest. Patient status at 1 year and survival time in days were abstracted from medical records. Cox regression analysis was used to examine the relationship between the psychosocial factors of interest and mortality after adjusting for relevant biobehavioral factors. Twenty-nine percent (n = 25) of participants died within 1 year of HSCT. After covarying for disease type, individuals with the highest spiritual absence and problematic compliance scores were significantly more likely to die 1-year post-HSCT (hazard ratio [HR] = 2.49, P = .043 and HR = 3.74, P = .029, respectively), particularly secondary to infection, sepsis, or graft-versus-host disease (GVHD) (HR = 4.56, P = .01 and HR = 5.61, P = .014), relative to those without elevations on these scales. Depression was not associated with 1-year mortality, and problematic compliance did not mediate the relationship between spiritual absence and mortality. These preliminary results suggest that both spiritual absence and problematic compliance may be associated with poorer survival following HSCT. Future research should examine these relations in a larger sample using a more comprehensive assessment of spirituality. PMID:20227510

  7. Near-horizon circular orbits and extremal limit for dirty rotating black holes

    NASA Astrophysics Data System (ADS)

    Zaslavskii, O. B.

    2015-08-01

    We consider generic rotating axially symmetric "dirty" (surrounded by matter) black holes. Near-horizon circular equatorial orbits are examined in two different cases of near-extremal (small surface gravity κ ) and exactly extremal black holes. This has a number of qualitative distinctions. In the first case, it is shown that such orbits can lie as close to the horizon as one wishes on suitably chosen slices of space-time when κ →0 . This generalizes the observation of T. Jacobson [Classical Quantum Gravity 28, 187001 (2011), 10.1088/0264-9381/28/18/187001] made for the Kerr metric. If a black hole is extremal (κ =0 ), circular on-horizon orbits are impossible for massive particles but, in general, are possible in its vicinity. The corresponding black hole parameters determine also the rate with which a fine-tuned particle on the noncircular near-horizon orbit asymptotically approaches the horizon. Properties of orbits under discussion are also related to the Bañados-Silk-West effect of high energy collisions near black holes. Impossibility of the on-horizon orbits in question is manifestation of kinematic censorship that forbids infinite energies in collisions.

  8. Space Launch Initiative: New Capabilities ... New Horizons

    NASA Technical Reports Server (NTRS)

    Dumbacher, Daniel L.

    2002-01-01

    This paper presents NASA's Space Launch Initiative (SLI) with new capabilities and new horizons. The topics include: 1) Integrated Space Transportation Plan; 2) SLI: The Work of an Nation; 3) SLI Goals and Status; 4) Composites and Materials; and 5) SLI & DoD/USAF Collaboration. This paper is presented in viewgraph form.

  9. Space Launch Initiative: New Capabilities - New Horizons

    NASA Technical Reports Server (NTRS)

    Dumbacher, Daniel; Smith, Dennis E. (Technical Monitor)

    2002-01-01

    This paper presents NASA's Space Launch Initiative (SLI) with new capabilities and new horizons. The topics include: 1) Integrated Space Transportation Plan; 2) SLI: The Work of a Nation; 3) SLI Goals and Status; 4) Composites and Materials; and 5) SLI and DOD/USAF Collaboration. This paper is in viewgraph form.

  10. Automatic star-horizon angle measurement system

    NASA Technical Reports Server (NTRS)

    Koerber, K.; Koso, D. A.; Nardella, P. C.

    1969-01-01

    Automatic star horizontal angle measuring aid for general navigational use incorporates an Apollo type sextant. The eyepiece of the sextant is replaced with two light detectors and appropriate circuitry. The device automatically determines the angle between a navigational star and a unique point on the earths horizon as seen on a spacecraft.

  11. The NMC Horizon Report: 2013 Museum Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Adams Becker, S.; Freeman, A.

    2013-01-01

    The "NMC Horizon Report: 2013 Museum Edition," is a co-production with the Marcus Institute for Digital Education in the Arts (MIDEA), and examines six emerging technologies for their potential impact on and use in education and interpretation within the museum environment: BYOD (Bring Your Own Device), crowdsourcing, electronic…

  12. Gateway's Horizon: A Center of Excellence

    ERIC Educational Resources Information Center

    Herring, Jayne; Colony, Lee

    2007-01-01

    This article describes Gateway Technical College's Horizon Center for Transportation Technology, located in Kenosha, Wisconsin, which was the product of collaboration with business and industry, community support and a U.S. Department of Labor (DOL) grant. The center, which opened this fall, is a prime example of a sustainable community…

  13. New Concepts on the Educational Horizon.

    ERIC Educational Resources Information Center

    Gilchrist, Robert S.; Mitchell, Edna

    Four dimensions in education provide a basis for discussing future horizons: (1) curriculum development, (2) teacher education, (3) administration and organization, and (4) research and development. These areas are interdependent, and one cannot be improved or changed without affecting the other areas. Within these areas, some of the broad changes…

  14. New Horizons in Mathematics and Science Education.

    ERIC Educational Resources Information Center

    Thorson, Annette, Ed.

    2001-01-01

    This journal, intended for classroom teachers, provides a collection of essays organized around the theme of new horizons in mathematics and science education as well as a guide to instructional materials related to the theme. Topics addressed in the essays include digital libraries, the future of science curricula, integrated curricula, and…

  15. Agriculture’s Ethical Horizon, book review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Roughly 6.5 billion people inhabit the earth, but over 1 billion people regularly go hungry. This food shortfall poses an ethical dilemma for agriculture, and Agriculture's Ethical Horizon grapples with this dilemma. It argues that agricultural productivity has been the quintessential value of agr...

  16. Health Care Costs 1 Year After Pediatric Traumatic Brain Injury

    PubMed Central

    Rivara, Frederick P.; Vavilala, Monica S.

    2015-01-01

    Objectives. This study sought to estimate total health care costs for mild, moderate, and severe pediatric traumatic brain injury (TBI) and to compare individual- and population-level costs across levels of TBI severity. Methods. Using 2007 to 2010 MarketScan Commercial Claims and Encounters data, we estimated total quarterly health care costs 1 year after TBI among enrollees (aged < 18 years). We compared costs across levels of TBI severity using generalized linear models. Results. Mild TBI accounted for 96.6% of the 319 103 enrollees with TBI; moderate and severe TBI accounted for 1.7% and 1.6%, respectively. Adjusted individual health care costs for moderate and severe TBI were significantly higher than mild TBI in the year after injury (P < .01). At the population level, moderate and severe TBI costs were 88% and 75% less than mild TBI, respectively. Conclusions. Individually, moderate and severe TBI initially generated costs that were markedly higher than those of mild TBI. At the population level, costs following mild TBI far exceeded those of more severe cases, a result of the extremely high population burden of mild TBI. PMID:26270293

  17. Vegetarianism. New Horizons in Nutrition.

    ERIC Educational Resources Information Center

    Arnold, Justine; Grogan, Jane, Ed.

    This instructional handbook is one of a series of ten packets designed to form a comprehensive course in nutrition for secondary students. This unit examines the vegetarian diet as a viable alternative, and at the same time, it introduces the topics of protein and vitamin B12. It contains a page of teaching suggestions, a pre-test for the…

  18. Prediction horizon effects on stochastic modelling hints for neural networks

    SciTech Connect

    Drossu, R.; Obradovic, Z.

    1995-12-31

    The objective of this paper is to investigate the relationship between stochastic models and neural network (NN) approaches to time series modelling. Experiments on a complex real life prediction problem (entertainment video traffic) indicate that prior knowledge can be obtained through stochastic analysis both with respect to an appropriate NN architecture as well as to an appropriate sampling rate, in the case of a prediction horizon larger than one. An improvement of the obtained NN predictor is also proposed through a bias removal post-processing, resulting in much better performance than the best stochastic model.

  19. The Pluto System As Seen By New Horizons Spacecraft

    NASA Video Gallery

    The Pluto system as NASA’s New Horizons spacecraft saw it in July 2015. This animation, made with real images taken by New Horizons, begins with Pluto flying in for its close-up on July 14; we then...

  20. SETAC launches global horizon scanning/research prioritization project

    EPA Science Inventory

    The SETAC World Council is pleased to announce the initiation of a Global Horizon Scanning and Prioritization Project aimed at identifying geographically specific research needs to address stressor impacts on environmental quality. In recent years, horizon scanning and research ...

  1. Varicella paediatric hospitalisations in Belgium: a 1-year national survey

    PubMed Central

    Blumental, Sophie; Sabbe, Martine; Lepage, Philippe

    2016-01-01

    Background Varicella universal vaccination (UV) has been implemented in many countries for several years. Nevertheless, varicella UV remains debated in Europe and few data are available on the real burden of infection. We assessed the burden of varicella in Belgium through analysis of hospitalised cases during a 1-year period. Methods Data on children admitted to hospital with varicella were collected through a national network from November 2011 to October 2012. Inclusion criteria were either acute varicella or related complications up to 3 weeks after the rash. Results Participation of 101 hospitals was obtained, covering 97.7% of the total paediatric beds in Belgium. 552 children were included with a median age of 2.1 years. Incidence of paediatric varicella hospitalisations reached 29.5/105 person-years, with the highest impact among those 0–4 years old (global incidence and odds of hospitalisation: 79/105 person-years and 1.6/100 varicella cases, respectively). Only 14% (79/552) of the cohort had an underlying chronic condition. 65% (357/552) of children had ≥1 complication justifying their admission, 49% were bacterial superinfections and 10% neurological disorders. Only a quarter of children (141/552) received acyclovir. Incidence of complicated hospitalised cases was 19/105 person-years. Paediatric intensive care unit admission and surgery were required in 4% and 3% of hospitalised cases, respectively. Mortality among Belgian paediatric population was 0.5/106 and fatality ratio 0.2% among our cohort. Conclusions Varicella demonstrated a substantial burden of disease in Belgian children, especially among the youngest. Our thorough nationwide study, run in a country without varicella UV, offers data to support varicella UV in Belgium. PMID:26130380

  2. New horizons in osteoporosis therapies.

    PubMed

    Harsløf, Torben; Langdahl, Bente L

    2016-06-01

    Efficient therapies are available for the treatment of osteoporosis, however, there are still unmet needs. Anti-resorptive therapies only increase bone mineral density to a certain extent and reduce the risk of non-vertebral fractures by 20%, only one anabolic option is available-the effect of which levels off over time, and the evidence for combination therapy targeting both resorption and formation is limited. The current review will focus on emerging treatments of osteoporosis with the potential of enhanced anabolic effects (romosozumab and abaloparatide) or uncoupling of resorption and formation (odanacatib and romosozumab) as well as the effect of combination therapy. PMID:26989807

  3. The dogger reef horizons of the Moroccan Central High Atlas: New data on their development

    NASA Astrophysics Data System (ADS)

    Ait Addi, Abdellah

    2006-06-01

    In the Central High Atlas, N of Errachidia, three major reef horizons in the Bajocian carbonate series of the Atlasic Basin were studied recently. The results of the study are based on fieldwork with an emphasis on stratigraphy, morphology and sedimentary patterns of detailed field sections. The lower reef horizon is composed of smaller build-ups which developed during the Aalenian-Lower Bajocian interval. At that time the depositional environment favored the production of both basinal and platform facies. This reef horizon is located only on the southern platform rim. Its development within the trough was controlled by synsedimentary block tilting, triggered by rifting, which was related to an ancient fracture zones inherited from the Triassic. Formed during the later stages of a rising sea-level, this horizon reflects a high carbonate production on the southern platform area. In the basin area, the second reef horizon presents relatively larger bodies (" patch reefs"). It consists of two major reef levels, separated by an interval of marls interspersed with thin-bedded limestones, developed most probably during Early? to Late Bajocian. For the duration of this time, within two 3rd order sequences, progradational shelfal units extended the platform facies northward to the basin center, covering a large area. Within a long-term transgressive/regressive cycle, throughout the Middle Aalenian-Bajocian, these reef horizons changed their structural growth to aggrading stacking patterns. The third reef horizon belongs to the lower part of the upper member of the Tazigzaout Formation, and shows the same sedimentary evolution as the second reef horizon underneath. It fits into a 2nd order geodynamic regressive cycle (upper part of Upper Bajocian-Bathonian pp.). It appears, that the development of the second and third reef horizon's forced the platform to prograde towards the N, NW and E during a late highstand, when accommodation was decreasing. However, depending on the

  4. Rindler-like Horizon in Spherically Symmetric Spacetime

    NASA Astrophysics Data System (ADS)

    Yang, Jinbo; He, Tangmei; Zhang, Jingyi

    2016-02-01

    In this paper, the Rindler-like horizon in a spherically symmetric spacetime is proposed. It is showed that just like the Rindler horizon in Minkowski spacetimes, there is also a Rindler-like horizon to a family of special observers in general spherically symmetric spacetimes. The entropy of this type of horizon is calculated with the thin film brick-wall model. The significance of entropy is discussed. Our results imply some connection between Bekeinstein-Hawking entropy and entanglement entropy.

  5. Rindler-like Horizon in Spherically Symmetric Spacetime

    NASA Astrophysics Data System (ADS)

    Yang, Jinbo; He, Tangmei; Zhang, Jingyi

    2016-07-01

    In this paper, the Rindler-like horizon in a spherically symmetric spacetime is proposed. It is showed that just like the Rindler horizon in Minkowski spacetimes, there is also a Rindler-like horizon to a family of special observers in general spherically symmetric spacetimes. The entropy of this type of horizon is calculated with the thin film brick-wall model. The significance of entropy is discussed. Our results imply some connection between Bekeinstein-Hawking entropy and entanglement entropy.

  6. Weight changes in children in foster care for 1 year

    PubMed Central

    Schneiderman, Janet U.; Smith, Caitlin; Arnold, Janet S.; Fuentes, Jorge; Duan, Lei

    2013-01-01

    Objective The aims of this study of predominately racial/ethnic minority children in foster care (N = 360, birth to 19 years old) in Los Angeles, CA were to examine the (1) prevalence of obesity (≥ 95 percentile) and overweight/obese(≥ 85 percentile) upon entrance to foster care (T1) and after 1 year in foster care (T2); (2) comparison of high weight categories to national statistics; (3) relationship of changes in weight status to age, reason for entry into foster care, and placement. Methods Chi-square test and McNemar test comparing paired proportions were used to determine whether there were significant changes in the proportion of high weight categories between T1 and T2. Chi-square test or Fisher’s exact test were used to evaluated the association between age, placement, and reason for foster care with the change in weight category. Changes in weight were categorized as (1) decreased in weight, (2) remained at overweight or obese, (3) increased in weight, or (4) remained normal. Results The proportion of obese and obese/overweight children between age 2 and 5 were significantly lower at T2 than T1. There were no significant changes in the prevalence of obesity for the total population at T2. Children age 6 or older had a higher prevalence of obesity and overweight/obesity compared to national statistics. Of children at all ages, 64.7% of children of all ages entered foster care with a normal weight and stayed in the normal range during their first year in foster care, 12.2% decreased their weight, 15.4% remained overweight or obese, and 7.7% increased their weight. Age and parental substance use was related to change in weight category from T1 to T2. Conclusions Children did not become more overweight or obese in foster care; however 28% of the children were obese or overweight upon entry into foster care. Children who are 6 years or older and obese upon entering foster care should be targeted for weight reduction. The pediatric community and child

  7. Through the looking glass: why the `cosmic horizon' is not a horizon

    NASA Astrophysics Data System (ADS)

    van Oirschot, Pim; Kwan, Juliana; Lewis, Geraint F.

    2010-06-01

    The present standard model of cosmology, Λ cold dark matter (ΛCDM), contains some intriguing coincidences. Not only are the dominant contributions to the energy density approximately of the same order at the present epoch, but we also note that contrary to the emergence of cosmic acceleration as a recent phenomenon, the time-averaged value of the deceleration parameter over the age of the Universe is nearly zero. Curious features like these in ΛCDM give rise to a number of alternate cosmologies being proposed to remove them, including models with an equation of state w = -1/3. In this paper, we examine the validity of some of these alternate models and we also address some persistent misconceptions about the Hubble sphere and the event horizon that lead to erroneous conclusions about cosmology. Research undertaken as part of the Commonwealth Cosmology Initiative (CCI: http://www.thecci.org), an international collaboration supported by the Australian Research Council. E-mail: pimvanoirschot@gmail.com

  8. Analyticity of event horizons of five-dimensional multi-black holes with nontrivial asymptotic structure

    SciTech Connect

    Kimura, Masashi

    2008-08-15

    We show that there exist five-dimensional multi-black hole solutions which have analytic event horizons when the space-time has nontrivial asymptotic structure, unlike the case of five-dimensional multi-black hole solutions in asymptotically flat space-time.

  9. Rogue events in the group velocity horizon

    PubMed Central

    Demircan, Ayhan; Amiranashvili, Shalva; Brée, Carsten; Mahnke, Christoph; Mitschke, Fedor; Steinmeyer, Günter

    2012-01-01

    The concept of rogue waves arises from a mysterious and potentially calamitous phenomenon of oceanic surfaces. There is mounting evidence that they are actually commonplace in a variety of different physical settings. A set of defining criteria has been advanced; this set is of great generality and therefore applicable to a wide class of systems. The question arises naturally whether there are generic mechanisms responsible for extreme events in different systems. Here we argue that under suitable circumstances nonlinear interaction between weak and strong waves results in intermittent giant waves with all the signatures of rogue waves. To obtain these circumstances only a few basic conditions must be met. Then reflection of waves at the so-called group-velocity horizon occurs. The connection between rogue waves and event horizons, seemingly unrelated physical phenomena, is identified as a feature common in many different physical systems. PMID:23152941

  10. Horizon ratio bound for inflationary fluctuations.

    PubMed

    Dodelson, Scott; Hui, Lam

    2003-09-26

    We demonstrate that the gravity wave background amplitude implies a robust upper bound on the wavelength-to-horizon ratio at the end of inflation: lambda/H(-1) less than or approximately equal e(60), as long as the cosmic energy density does not drop faster than radiation subsequent to inflation. This limit implies that N, the number of e-folds between horizon exit and the end of inflation for wave modes of interest, is less, similar 60 plus a model-dependent factor-for vast classes of slow-roll models, N less than or approximately equal 67. As an example, this bound solidifies the tension between observations of the cosmic microwave background anisotropies and chaotic inflation with a phi(4) potential by closing the escape hatch of large N (<62). PMID:14525296

  11. Horizon Missions Technology Study. [for space exploration

    NASA Technical Reports Server (NTRS)

    Anderson, John L.

    1992-01-01

    The purpose of the HMT Study was to develop and demonstrate a systematic methodology for identifying and evaluating innovative technology concepts offering revolutionary, breadkthrough-type capabilities for advanced space missions and for assessing their potential mission impact. The methodology is based on identifying the new functional, operational and technology capabilities needed by hypothetical 'Horizon' space missions that have performance requirements that cannot be met, even by extrapolating known space technologies. Nineteen Horizon Missions were selected to represent a collective vision of advanced space missions of the mid-21st century. The missions typically would occur beyond the lifetime of current or planned space assets. The HM methodology and supporting data base may be used for advanced technology planning, advanced mission planning and multidisciplinary studies and analyses.

  12. Horizon crossing and inflation with large {eta}

    SciTech Connect

    Kinney, William H.

    2005-07-15

    I examine the standard formalism of calculating curvature perturbations in inflation at horizon crossing, and derive a general relation which must be satisfied for the horizon-crossing formalism to be valid. This relation is satisfied for the usual cases of power-law and slow-roll inflation. I then consider a model for which the relation is strongly violated, and the curvature perturbation evolves rapidly on superhorizon scales. This model has Hubble slow-roll parameter {eta}=3, but predicts a scale-invariant spectrum of density perturbations. I consider the case of hybrid inflation with large {eta}, and show that such solutions do not solve the '{eta} problem' in supergravity. These solutions correspond to field evolution which has not yet relaxed to the inflationary attractor solution, and may make possible new, more natural models on the string landscape.

  13. Finding apparent horizons in numerical relativity

    NASA Astrophysics Data System (ADS)

    Thornburg, Jonathan

    1996-10-01

    We review various algorithms for finding apparent horizons in 3+1 numerical relativity. We then focus on one particular algorithm, in which we pose the apparent horizon equation H≡∇ini+Kijninj-K=0 as a nonlinear elliptic (boundary-value) PDE on angular-coordinate space for the horizon shape function r=h(θ,φ), finite difference this PDE, and use Newton's method or a variant to solve the finite difference equations. We describe a method for computing the Jacobian matrix of the finite differenced H(h) sH (sh) function by symbolically differentiating the finite difference equations, giving the Jacobian elements directly in terms of the finite difference molecule coefficients used in computing sH (sh). Assuming the finite differencing scheme commutes with linearization, we show how the Jacobian elements may be computed by first linearizing the continuum H(h) equations, then finite differencing the linearized continuum equations. (This is essentially just the ``Jacobian part'' of the Newton-Kantorovich method for solving nonlinear PDEs.) We tabulate the resulting Jacobian coefficients for a number of different sH (sh) and Jacobian computation schemes. We find this symbolic differentiation method of computing the Jacobian to be much more efficient than the usual numerical-perturbation method, and also much easier to implement than is commonly thought. When solving the discrete sH (sh)=0 equations, we find that Newton's method generally shows robust convergence. However, we find that it has a small (poor) radius of convergence if the initial guess for the horizon position contains significant high-spatial-frequency error components, i.e., angular Fourier components varying as (say) cosmθ with m>~8. (Such components occur naturally if spacetime contains significant amounts of high-frequency gravitational radiation.) We show that this poor convergence behavior is not an artifact of insufficient resolution in the finite difference grid; rather, it appears to be caused

  14. Results with SynCardia total artificial heart beyond 1 year.

    PubMed

    Torregrossa, Gianluca; Morshuis, Michiel; Varghese, Robin; Hosseinian, Leila; Vida, Vladimiro; Tarzia, Vincenzo; Loforte, Antonio; Duveau, Daniel; Arabia, Francisco; Leprince, Pascal; Kasirajan, Vigneshwa; Beyersdorf, Friedhelm; Musumeci, Francesco; Hetzer, Roland; Krabatsch, Thoamas; Gummert, Jan; Copeland, Jack; Gerosa, Gino

    2014-01-01

    Mechanical circulatory support devices have been increasingly used for long-term support. We reviewed outcomes in all patients supported with a SynCardia total artificial heart (TAH) for more than 1 year to assess its safety in long-term support. As of December 2011, all 47 patients who received the TAH from 10 centers worldwide were included in this retrospective study. Clinical data were collected on survival, infections, thromboembolic and hemorrhagic events, device failures, and antithrombotic therapy. The mean age of patients was 50 ± 1.57 years, the median support time was 554 days (range 365-1373 days). The primary diagnosis was dilated cardiomiopathy in 23 patients, ischemic in 15, and "other" in 9. After a minimum of 1 year of support, 34 patients (72%) were successfully transplanted, 12 patients (24%) died while on device support, and 1 patient (2%) is still supported. Five patients (10%) had a device failure reported. Major complications were as follows: systemic infections in 25 patients (53%), driveline infections in 13 patients (27%), thromboembolic events in 9 patients (19%), and hemorrhagic events in 7 patients (14%). SynCardia TAH has proven to be a reliable and effective device in replacing the entire heart. In patients who reached a minimum of 1 year of support, device failure rate is acceptable and only in two cases was the leading cause of death. Infections and hemorrhagic events were the major causes of death. Patients who remain supported beyond 1 year are still likely to survive to transplantation. PMID:25158888

  15. Cognitive and affective assessment in day care versus institutionalized elderly patients: a 1-year longitudinal study

    PubMed Central

    Maseda, Ana; Balo, Aránzazu; Lorenzo–López, Laura; Lodeiro–Fernández, Leire; Rodríguez–Villamil, José Luis; Millán–Calenti, José Carlos

    2014-01-01

    Purpose Cognitive decline and depression are two common mental health problems that may create a need for long-term care among the elderly. In the last decade, the percentage of older adults who receive health care in nursing homes, day care centers, or home support services has increased in Europe. The objectives of this descriptive and nonrandomized longitudinal study were to evaluate and to compare the cognitive and affective evolution of day care versus institutionalized older patients through a 1-year period, and to assess the presence of cognitive and affective impairment as a function of the care setting. Patients and methods Ninety-four patients were assessed at baseline, and 63 (67.0%) were reassessed 1 year later. Neuropsychological assessment included measures of cognitive performance (general cognitive status, visuospatial, and language abilities) and affective status (depressive symptoms). Results Our findings indicated that the majority of the participants (day care and institutionalized patients) had mild–moderate cognitive impairment at baseline, which significantly increased in both groups after 1-year follow-up. However, the rate of change in global cognitive function did not significantly differ between groups over time. Regarding language abilities, naming function maintained among day care patients in comparison with institutionalized patients, who showed worse performance at follow-up. As regards to affective status, results revealed that institutionalized patients had a significant reduction in depressive symptoms at follow-up, when compared to day care patients. Results also highlight the high frequency of cognitive impairment and depressive symptoms regardless of the care setting. Conclusion Our findings revealed a similar global cognitive decline rate between patients receiving day care services and those residing in a nursing home at the 1-year follow-up, and slightly different trajectories in other outcomes such as naming function and

  16. Cost-Effectiveness Analysis of 1-Year Treatment with Golimumab/Standard Care and Standard Care Alone for Ulcerative Colitis in Poland

    PubMed Central

    Stawowczyk, Ewa; Kawalec, Paweł; Pilc, Andrzej

    2016-01-01

    Objective The objective of this study was to assess the cost-effectiveness of induction and maintenance treatment up to 1 year of ulcerative colitis with golimumab/standard care and standard care alone in Poland. Methods A Markov model was used to estimate the expected costs and effects of golimumab/standard care and a standard care alone. For each treatment option the costs and quality adjusted life years were calculated to estimate the incremental cost-utility ratio. The analysis was performed from the perspective of the Polish public payer and society over a 30-years time horizon. The clinical parameters were derived mainly from the PURSUIT-SC and PURSUIT-M clinical trials. Different direct and indirect costs and utility values were assigned to the various model health states. Results The treatment of ulcerative colitis patients with golimumab/standard care instead of a standard care alone resulted in 0.122 additional years of life with full health. The treatment with golimumab/standard care was found to be more expensive than treatment with the standard care alone from the public payer perspective and from social perspective. The incremental cost-utility ratio of golimumab/standard care compared to the standard care alone is estimated to be 391,252 PLN/QALY gained (93,155 €/QALYG) from public payer perspective and 374,377 PLN/QALY gained (89,137 €/QALYG) from social perspective. Conclusions The biologic treatment of ulcerative colitis patients with golimumab/standard care is more effective but also more costly compared with standard care alone. PMID:27494322

  17. Transformation of polymetallic dust in the organic horizon of Al-Fe-humus podzol (field experiment)

    NASA Astrophysics Data System (ADS)

    Lyanguzova, I. V.; Goldvirt, D. K.; Fadeeva, I. K.

    2015-07-01

    Scanning electron microscopy with an X-ray spectral microanalysis showed that the ash matter from the organic horizons (after ignition) of control and experimental plots mainly (>85%) consists of different soil-forming minerals and iron oxides (particularly magnetite). From 10% to 15% of particles in the organic horizon of Al-Fe-humus podzol (Albic Rustic Podzol) of the experimental plot were represented by polymetallic ball-shaped dust particles that were preserved in the soil without significant transformation for 14 years after their artificial application. The total contents of Cu, Pb, As, and Ni in the organic horizon on the experimental plot were 22-100 times higher than those in the control; the contents of Zn and Fe were 2-5 times higher. The sequence of chemical elements according to their total contents in the samples of control and experimental plots was different. The portion of available forms of heavy metal (Ni, Cu, and Co) compounds extractable with 1.0 M HCl averaged 20-30% of their total contents in the soil. More than 80% of acid-soluble forms of heavy metals were concentrated in the organic horizon of contaminated podzol soil, which represents the biogeochemical barrier to the migration of pollutants down the soil profile. Durable fixation of heavy metals in the organic horizon and their weak migration into the mineral soil layers significantly hamper the processes of self-purification of contaminated soils.

  18. Finding KBO flyby targets for New Horizons

    NASA Astrophysics Data System (ADS)

    Spencer, John; Trilling, David; Buie, Marc; Parker, Alex; Tholen, David; Stern, S. Alan

    2014-02-01

    We propose to continue the search for Kuiper Belt Objects (KBOs) that can be reached by the New Horizons spacecraft after its 2015 Pluto flyby. This first flyby of a small (~50 km) KBO would revolutionize our understanding of KBOs, providing information that can be extrapolated to hundreds of thousands of similar KBOs. Our 2011 search discovered three objects that could be targeted with only about twice the fuel that New Horizons has available during excellent seeing, but seeing was insufficient to achieve this depth over the entire search area in 2012 or 2013. Deepening the search in 2014, taking advantage of lower star density and the shrinking search area, has a good chance of finding a targetable object given sufficiently good seeing, especially with Hyper Suprime Cam. We expect about 2.5 targetable objects with R less 26.0 in the HSC field of view. We will also refine the orbits of previously discovered objects, including ones that can be observed from a distance by New Horizons on its passage through the Kuiper Belt.

  19. Accurate, reliable prototype earth horizon sensor head

    NASA Technical Reports Server (NTRS)

    Schwarz, F.; Cohen, H.

    1973-01-01

    The design and performance is described of an accurate and reliable prototype earth sensor head (ARPESH). The ARPESH employs a detection logic 'locator' concept and horizon sensor mechanization which should lead to high accuracy horizon sensing that is minimally degraded by spatial or temporal variations in sensing attitude from a satellite in orbit around the earth at altitudes in the 500 km environ 1,2. An accuracy of horizon location to within 0.7 km has been predicted, independent of meteorological conditions. This corresponds to an error of 0.015 deg-at 500 km altitude. Laboratory evaluation of the sensor indicates that this accuracy is achieved. First, the basic operating principles of ARPESH are described; next, detailed design and construction data is presented and then performance of the sensor under laboratory conditions in which the sensor is installed in a simulator that permits it to scan over a blackbody source against background representing the earth space interface for various equivalent plant temperatures.

  20. Horizon Science Experiment for Mars Global Surveyor

    NASA Astrophysics Data System (ADS)

    Martin, T. Z.

    1997-07-01

    The Mars Horizon Sensor Assembly on the MGS orbiter monitors the orientation of the spacecraft relative to the limb by sensing atmospheric emission in the 15 mu m CO2 band. These data are used to maintain nadir pointing for the remote sensing instrument suite. The set of 5.5deg tall triangular fields of view normally straddle the limb, and cover quadrants 90deg apart around the limb. As an engineering device, the MHSA benefits from Mars' atmosphere being spatially bland at 15 mu m. However, these data will carry information about the thermal state of the atmosphere, which is subject to diurnal, seasonal, latitudinal, and dust-storm related variations, as well as possible wave effects. The Mariner 7 IRS, Mariner 9 IRIS, and Viking IRTM all demonstrated such variability. The Horizon Science Experiment (HORSE) is intended to glean new insight into atmospheric variation from the MGS horizon sensors, with continuous data flow to the Earth in the engineering stream, and a rapid buildup of spatial coverage. MHSA data will also be used to monitor atmospheric thermal behavior during the aerobraking of MGS in late 1997.

  1. The Tookoonooka marine impact horizon, Australia: Sedimentary and petrologic evidence

    NASA Astrophysics Data System (ADS)

    Bron, Katherine A.; Gostin, Victor

    2012-02-01

    Ejecta from the large subsurface Tookoonooka impact structure have been found in the Lower Cretaceous strata of the extensive Eromanga Basin of central Australia. Observations from 31 wells spanning 400,000 km2 of the basin provide compelling evidence for the presence of a marine impact horizon of regional extent. Drill core was examined to determine the sedimentary context of the Tookoonooka impact event, the presence of ejecta, and the nature of the impact horizon. The base of the Wyandra Sandstone Member of the Cadna-owie Formation is an unconformity commonly overlain by very poorly sorted sediment with imbricated pebbles, exotic clasts, and occasional boulders. The basal Wyandra Sandstone Member is bimodal: a fine sand mode reflects an ambient sediment contribution and a coarse mode is interpreted to be impact-derived. Wells Thargomindah-1 and Eromanga-1, within four crater radii of Tookoonooka, contain distinctive clast-supported breccia-conglomerate beds at the base of the Wyandra Sandstone Member. Clasts in these beds include altered accretionary and melt impactoclasts, as well as lithic and mineral grains corresponding to the Tookoonooka target rock sequence, including basement. Petrographic evidence includes shock metamorphosed quartz and lithic grains with planar deformation features. These breccia-conglomerates are in stark contrast to the underlying, laterally persistent, unimodal Cadna-owie sediments and overlying shales deposited in an epeiric sea. The base of the Wyandra Sandstone Member is therefore interpreted to be the Tookoonooka impact horizon. The timing of the impact event is confirmed to be the Barremian-Aptian boundary, at 125 ± 1 Ma. The Wyandra Sandstone Member preserves both impact ejecta and postimpact marine sediments.

  2. Is the Gravitational-Wave Ringdown a Probe of the Event Horizon?

    NASA Astrophysics Data System (ADS)

    Cardoso, Vitor; Franzin, Edgardo; Pani, Paolo

    2016-04-01

    It is commonly believed that the ringdown signal from a binary coalescence provides a conclusive proof for the formation of an event horizon after the merger. This expectation is based on the assumption that the ringdown waveform at intermediate times is dominated by the quasinormal modes of the final object. We point out that this assumption should be taken with great care, and that very compact objects with a light ring will display a similar ringdown stage, even when their quasinormal-mode spectrum is completely different from that of a black hole. In other words, universal ringdown waveforms indicate the presence of light rings, rather than of horizons. Only precision observations of the late-time ringdown signal, where the differences in the quasinormal-mode spectrum eventually show up, can be used to rule out exotic alternatives to black holes and to test quantum effects at the horizon scale.

  3. Is the Gravitational-Wave Ringdown a Probe of the Event Horizon?

    PubMed

    Cardoso, Vitor; Franzin, Edgardo; Pani, Paolo

    2016-04-29

    It is commonly believed that the ringdown signal from a binary coalescence provides a conclusive proof for the formation of an event horizon after the merger. This expectation is based on the assumption that the ringdown waveform at intermediate times is dominated by the quasinormal modes of the final object. We point out that this assumption should be taken with great care, and that very compact objects with a light ring will display a similar ringdown stage, even when their quasinormal-mode spectrum is completely different from that of a black hole. In other words, universal ringdown waveforms indicate the presence of light rings, rather than of horizons. Only precision observations of the late-time ringdown signal, where the differences in the quasinormal-mode spectrum eventually show up, can be used to rule out exotic alternatives to black holes and to test quantum effects at the horizon scale. PMID:27176511

  4. Neural network-based finite horizon stochastic optimal control design for nonlinear networked control systems.

    PubMed

    Xu, Hao; Jagannathan, Sarangapani

    2015-03-01

    The stochastic optimal control of nonlinear networked control systems (NNCSs) using neuro-dynamic programming (NDP) over a finite time horizon is a challenging problem due to terminal constraints, system uncertainties, and unknown network imperfections, such as network-induced delays and packet losses. Since the traditional iteration or time-based infinite horizon NDP schemes are unsuitable for NNCS with terminal constraints, a novel time-based NDP scheme is developed to solve finite horizon optimal control of NNCS by mitigating the above-mentioned challenges. First, an online neural network (NN) identifier is introduced to approximate the control coefficient matrix that is subsequently utilized in conjunction with the critic and actor NNs to determine a time-based stochastic optimal control input over finite horizon in a forward-in-time and online manner. Eventually, Lyapunov theory is used to show that all closed-loop signals and NN weights are uniformly ultimately bounded with ultimate bounds being a function of initial conditions and final time. Moreover, the approximated control input converges close to optimal value within finite time. The simulation results are included to show the effectiveness of the proposed scheme. PMID:25720004

  5. Chandra Uncovers New Evidence For Event Horizons Surrounding Black Holes

    NASA Astrophysics Data System (ADS)

    2001-01-01

    horizon is the defining characteristic of a black hole, but obviously it is very difficult to detect since any infalling material at the event horizon is observable for only an instant as it plunges inward at the speed of light," said McClintock. "The comparison of black holes and their close cousins, the neutron stars, may be the most promising way to get a handle on the event horizon." If the collapsed star is a neutron star with a solid surface, energy must be released when infalling matter strikes that surface. In contrast, if the accreting object is a black hole, there is no surface for the matter to strike. Instead, both the energy and the matter will be lost from view forever once they cross the event horizon. A small amount of energy can escape just before the matter crosses the event horizon, but the scientists believe that it should be much less than the energy released by matter hitting a neutron star surface. "Watching matter flowing into a black hole is like sitting upstream of a waterfall and watching the water seemingly vanish over the edge," said Narayan, chairman of the Harvard Astronomy Department. "However, if the waterfall were replaced by a dam -- the analog of a neutron star surface -- then the water would pile up and one would see a mighty lake". Why are dormant black hole sources a hundred times fainter than the neutron star sources? The amount of material falling towards the collapsed star and the subsequent energy release are believed to be nearly the same, whether the compact object is a black hole or a neutron star. Therefore, the remarkable difference in brightness comes, according to the team, because of the event horizon, where the inward pull of gravity becomes infinitely strong. This is in contrast to the situation of neutron stars that have a more normal surface. By observing the motion of the companion star in an X-ray nova, the mass of the collapsed star can be estimated. In some cases, this mass is more than three times that of the Sun

  6. Use of microcomputer in mapping depth of stratigraphic horizons in National Petroleum Reserve in Alaska

    USGS Publications Warehouse

    Payne, Thomas G.

    1982-01-01

    REGIONAL MAPPER is a menu-driven system in the BASIC language for computing and plotting (1) time, depth, and average velocity to geologic horizons, (2) interval time, thickness, and interval velocity of stratigraphic intervals, and (3) subcropping and onlapping intervals at unconformities. The system consists of three programs: FILER, TRAVERSER, and PLOTTER. A control point is a shot point with velocity analysis or a shot point at or near a well with velocity check-shot survey. Reflection time to and code number of seismic horizons are filed by digitizing tablet from record sections. TRAVERSER starts at a point of geologic control and, in traversing to another, parallels seismic events, records loss of horizons by onlap and truncation, and stores reflection time for geologic horizons at traversed shot points. TRAVERSER is basically a phantoming procedure. Permafrost thickness and velocity variations, buried canyons with low-velocity fill, and error in seismically derived velocity cause velocity anomalies that complicate depth mapping. Two depths to the top of the pebble is based shale are computed for each control point. One depth, designated Zs on seismically derived velocity. The other (Zw) is based on interval velocity interpolated linearly between wells and multiplied by interval time (isochron) to give interval thickness. Z w is computed for all geologic horizons by downward summation of interval thickness. Unknown true depth (Z) to the pebble shale may be expressed as Z = Zs + es and Z = Zw + ew where the e terms represent error. Equating the two expressions gives the depth difference D = Zs + Zw = ew + es A plot of D for the top of the pebble shale is readily contourable but smoothing is required to produce a reasonably simple surface. Seismically derived velocity used in computing Zs includes the effect of velocity anomalies but is subject to some large randomly distributed errors resulting in depth errors (es). Well-derived velocity used in computing Zw

  7. Testing numerically the null Cauchy horizon singularity inside Kerr black holes

    NASA Astrophysics Data System (ADS)

    Burko, Lior; Khanna, Gaurav; Zenginoĝlu, Anil

    2015-04-01

    The Cauchy horizon inside a Kerr black hole develops an instability that transforms it into a curvature singularity. Perturbative analyses are consistent with the picture arising from fully nonlinear simulations of spherical charged black holes: this singularity is deformational weak and null for early retarded times. Despite much interest in this long-standing problem, no numerical simulations of the interior of a perturbed Kerr black hole have been done to date. Here, we report on preliminary results obtained from a linear simulation of the evolution of the fields under the collapse of a test wave packet. We use recent developments to a Teukolsky equation solver, which use (event) horizon-penetrating, hyperboloidal coordinates, which compactify null infinity and penetrate through both horizons. This numerical technology allows us to penetrate through the event horizon, and probe the fields on the approach to the Cauchy horizon singularity. We study the behavior of the Weyl scalars ψ0 and ψ4 and of the curvature scalar RαβγδRαβγδ , and confront our results with those of perturbation analysis. Our results may be useful when planning fully nonlinear numerical studies of rotating black hole interiors.

  8. The quantum nonthermal radiation and horizon surface gravity of an arbitrarily accelerating black hole with electric charge and magnetic charge

    NASA Astrophysics Data System (ADS)

    Xie, Zhi-Kun; Pan, Wei-Zhen; Yang, Xue-Jun

    2013-03-01

    Using a new tortoise coordinate transformation, we discuss the quantum nonthermal radiation characteristics near an event horizon by studying the Hamilton-Jacobi equation of a scalar particle in curved space-time, and obtain the event horizon surface gravity and the Hawking temperature on that event horizon. The results show that there is a crossing of particle energy near the event horizon. We derive the maximum overlap of the positive and negative energy levels. It is also found that the Hawking temperature of a black hole depends not only on the time, but also on the angle. There is a problem of dimension in the usual tortoise coordinate, so the present results obtained by using a correct-dimension new tortoise coordinate transformation may be more reasonable.

  9. Radio Occultation Measurements of Pluto's Atmosphere with New Horizons

    NASA Astrophysics Data System (ADS)

    Hinson, D. P.; Linscott, I.; Tyler, G. L.; Bird, M. K.; Paetzold, M.; Strobel, D. F.; Summers, M. E.; Woods, W. W.; Stern, A.; Weaver, H. A., Jr.; Olkin, C.; Young, L. A.; Ennico Smith, K.; Gladstone, R.; Greathouse, T.; Kammer, J.; Parker, A. H.; Parker, J. W.; Retherford, K. D.; Schindhelm, E.; Singer, K. N.; Steffl, A.; Tsang, C.; Versteeg, M.

    2015-12-01

    The reconnaissance of the Pluto System by New Horizons included radio occultations at both Pluto and Charon. This talk will present the latest results from the Pluto occultation. The REX instrument onboard New Horizons received and recorded uplink signals from two 70-m antennas and two 34-m antennas of the NASA Deep Space Network - each transmitting 20 kW at 4.2-cm wavelength - during a diametric occultation by Pluto. At the time this was written only a short segment of data at occultation entry (193°E, 17°S) was available for analysis. The REX measurements extend unequivocally to the surface, providing the first direct measure of the surface pressure and the temperature structure in Pluto's lower atmosphere. Preliminary analysis yields a surface pressure of about 10 microbars, smaller than expected. Data from occultation exit (16°E, 15°N) are scheduled to arrive on the ground in late August 2015. Those observations will yield an improved estimate of the surface pressure, a second temperature profile, and a measure of the diameter of Pluto with a precision of a few hundred meters.

  10. Lagrangian Predictive Skill Assessment for the Deepwater Horizon Spill

    NASA Astrophysics Data System (ADS)

    Lipphardt, B. L.; Huntley, H. S.; Sulman, M.; Kirwan, A. D.

    2011-12-01

    The explosion and sinking of the Deepwater Horizon drilling platform produced enormous human, ecological, and economic impacts. At the same time this disaster provided an unprecedented amount of Lagrangian information on ocean processes, including a large number of surface and near-surface drifters deployed in the northeastern Gulf of Mexico as well as remotely sensed images of the surface oil slick. In addition several global and regional ocean model predictions were used to forecast the spill movements. These models generally exhibited large variations in the mesoscale flow near the Deepwater Horizon site, even though they all assimilated similar sets of ocean observations. This provides a unique opportunity to thoroughly assess model Lagrangian predictive skill. Here, the predictive skill of one model, a regional implementation of the Hybrid Coordinate Ocean Model (HYCOM), is evaluated using data from more than 80 drifter trajectories in the northern Gulf of Mexico. These trajectories are compared with maps of Lagrangian coherent structures, computed from near-surface model velocities, to determine whether the observations are consistent with the larger scale transport structure predicted by the model. We also discuss new metrics to assess model Lagrangian predictive skill of the plume movement.

  11. First Results from the Mars Global Surveyor Horizon Science Experiment

    NASA Astrophysics Data System (ADS)

    Martin, Terry

    1998-09-01

    The Horizon Science Experiment (HORSE) uses the Mars Horizon Sensor Assembly on the MGS orbiter to measure 15 micrometer band thermal emission from the Martian atmosphere. During the first phase of aerobraking for MGS, from September 1997 through March 1998, one of the four MGS quadrants was pointed well onto the planet consistently during the near-periapsis braking passes, allowing the device to obtain data on the latitudinal variation of middle atmospheric temperature (0.2 - 2 mbar). Of particular interest were the effects of a prominent dust storm at Ls 224, and the strong gradient of temperature near the north polar cap. The dust storm produced 10-12K warming in the middle atmosphere across the latitude range from -50 to +60 degrees over a time period of 97 hrs. The increase was most pronounced at the longitudes near 330 where the storm originated in the southern hemisphere. During Ls 260-278, the latitude of steepest latitudinal temperature gradient (the location of the northern polar vortex) varied with longitude in a primarily wave 2 mode, with an amplitude of about 8 degrees and one maximum at 120 longitude. A small wave 1 term is also present.

  12. Predicting abuse in adolescent dating relationships over 1 year: the role of child maltreatment and trauma.

    PubMed

    Wolfe, David A; Wekerle, Christine; Scott, Katreena; Straatman, Anna-Lee; Grasley, Carolyn

    2004-08-01

    Three mediators of the relationship between childhood maltreatment and dating violence perpetration during midadolescence (i.e., trauma-related symptoms, attitudes justifying dating violence, and empathy and self-efficacy in dating relationships) were tested over 1 year with a sample of students from 10 high schools (N = 1,317). Trauma-related symptoms had a significant cross-time effect on predicting incidents of dating violence for both boys and girls. Attitudes and empathy and self-efficacy did not predict dating violence over time, although they were correlated with such behavior at both time points. Child maltreatment is a distal risk factor for adolescent dating violence, and trauma-related symptoms act as a significant mediator of this relationship. The importance of longitudinal methodology that separates correlates from predictors is discussed. PMID:15311986

  13. Observation of an optical event horizon in a silicon-on-insulator photonic wire waveguide.

    PubMed

    Ciret, Charles; Leo, François; Kuyken, Bart; Roelkens, Gunther; Gorza, Simon-Pierre

    2016-01-11

    We report on the first experimental observation of an optical analogue of an event horizon in integrated nanophotonic waveguides, through the reflection of a continuous wave on an intense pulse. The experiment is performed in a dispersion-engineered silicon-on-insulator waveguide. In this medium, solitons do not suffer from Raman induced self-frequency shift as in silica fibers, a feature that is interesting for potential applications of optical event horizons. As shown by simulations, this also allows the observation of multiple reflections at the same time on fundamental solitons ejected by soliton fission. PMID:26832243

  14. Transport of four pharmaceuticals in different horizons of three soil types

    NASA Astrophysics Data System (ADS)

    Kodesova, Radka; Svatkova, Paula; Klement, Ales; Jaksik, Ondrej; Golovko, Oksana; Fer, Miroslav; Kocarek, Martin; Nikodem, Antonin; Grabic, Roman

    2015-04-01

    Soil structure, which varies in different soil types and the horizons of these soil types, has a significant impact on water flow and contaminant transport in soils. Transport of many contaminants is in addition strongly influenced by their sorption on soil particles. Transport of four pharmaceuticals (sulfamethoxazole, trimethoprim, atenolol and carbamazepine) was studied in soil columns (a diameter of 10.5 cm and a height of 13 cm) taken from all diagnostic horizons of three different soil types (Haplic Luvisol, Greyic Phaeozem and Haplic Cambisol). The irrigation by water contaminated by a mixture of all four compounds followed by ponding infiltration of distilled water was simulated and water outflow and solute concentrations from the bottom of the soil sample was monitored in time. The highest infiltration rates were observed for soil samples from the Bt horizons of the Greyic Phaeozem that exhibited prismatic structure, followed by rates observed in the Ap horizons of the Haplic Luvisol, Greyic Phaeozem and Haplic Cambisol (due to their granular soil structure and presence of root channels). The lowest infiltration rate was measured for the Bw horizon of the Haplic Cambisol, which had a poorly developed soil structure and a low fraction of macropores. Compound discharge was however also highly affected by their sorption on solids. The highest mobility was observed for sulfamethoxazole followed by carbamazepine atenolol and trimethoprim, which corresponds to measured sorption isotherms. Mobility of ionizable compounds in different soil samples was influenced by pH (i.e. degree and form of their ionization) and sites available for absorption. Mobility of sulfamethoxazole decreased with decreasing pH (i.e. the largest sorption measured in horizons of the Haplic Cambisol). While mobility of atenolol and trimethoprim decreased with increasing base cation saturation, and with increasing organic matter content for carbamazepine. As result of both affects (i.e. soil

  15. The horizon of the lightest black hole

    NASA Astrophysics Data System (ADS)

    Calmet, Xavier; Casadio, Roberto

    2015-09-01

    We study the properties of the poles of the resummed graviton propagator obtained by resumming bubble matter diagrams which correct the classical graviton propagator. These poles have been previously interpreted as black holes precursors. Here, we show using the horizon wave-function formalism that these poles indeed have properties which make them compatible with being black hole precursors. In particular, when modeled with a Breit-Wigner distribution, they have a well-defined gravitational radius. The probability that the resonance is inside its own gravitational radius, and thus that it is a black hole, is about one half. Our results confirm the interpretation of these poles as black hole precursors.

  16. Peripheral Vision Horizon Display (PVHD). Corrected Copy

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A Canadian invention, the peripheral vision horizon display (PVHD), shows promise in alleviating vertigo or disorientation in pilots flying under instrument conditions and easing the piloting task when flying in weather or other conditions requiring close attention to aircraft attitude instruments. A diversity of research and applied work was being done to investigate and validate the benefits of the PVHD during the years immediately preceding this conference. Organizers of the conference were able to assemble a group of outstanding presenters representing academic, industrial, and military. The theoretical foundation and applied use of the PVHD are discussed, and results from operational tests are presented.

  17. Prolate horizons and the Penrose inequality

    SciTech Connect

    Tippett, Benjamin K.

    2009-05-15

    The Penrose inequality has so far been proven in cases of spherical symmetry and in cases of zero extrinsic curvature. The next simplest case worth exploring would be nonspherical, nonrotating black holes with nonzero extrinsic curvature. Following Karkowski et al.'s construction of prolate black holes, we define initial data on an asymptotically flat spacelike 3-surface with nonzero extrinsic curvature that may be chosen freely. This gives us the freedom to define the location of the apparent horizon such that the Penrose inequality is violated. We show that the dominant energy condition is violated at the poles for all cases considered.

  18. Black hole thermodynamics from Euclidean horizon constraints.

    PubMed

    Carlip, S

    2007-07-13

    To explain black hole thermodynamics in quantum gravity, one must introduce constraints to ensure that a black hole is actually present. I show that for a large class of black holes, such "horizon constraints" allow the use of conformal field theory techniques to compute the density of states, reproducing the Bekenstein-Hawking entropy in a nearly model-independent manner. One standard string theory approach to black hole entropy arises as a special case, lending support to the claim that the mechanism may be "universal." I argue that the relevant degrees of freedom are Goldstone-boson-like excitations arising from the weak breaking of symmetry by the constraints. PMID:17678209

  19. European scientists' proposals for HORIZON 2000+

    NASA Astrophysics Data System (ADS)

    1994-10-01

    This programme, which has been given the name Horizon 2000+, will be presented to the press at 0900h on Monday 17 October 1994 at ESA Headquarters in Paris by Professor Lodewijk Woltjer, who chaired the committee of European scientific community representatives set up to consider the proposals submitted, and Professor Roger Bonnet, ESA's Science Programme Director. Journalists wishing to attend this press breakfast are requested to complete and return the attached form, if possible by fax: (33.1) 42.73.76.90.

  20. Phase Fluctuations at Goldstone Derived from 1-Year Site Testing Interferometer Data

    NASA Technical Reports Server (NTRS)

    Nessel, James A.; Acosta, Roberto J.; Morabito, David D.

    2009-01-01

    A two-element site test interferometer has been deployed at the NASA Deep Space Network (DSN) tracking complex in Goldstone, California, since May 2007. The interferometer system consists of two offset-fed 1.2 m parabolic reflectors which monitor atmospheric-induced amplitude and phase fluctuations on an unmodulated beacon signal (20.199 GHz) broadcast from a geostationary satellite (Anik F2). The geometry of the satellite and the ground-based infrastructure imposes a 48.5 elevation angle with a separation distance of 256 m along an east-west baseline. The interferometer has been recording phase fluctuation data, to date, for 1 yr with an overall system availability of 95 percent. In this paper, we provide the cumulative distribution functions (CDFs) for 1 year of recorded data, including phase rms, spatial structure function exponent, and surface meteorological measurements: surface wind speed, relative humidity, temperature, barometric pressure, and rain rate. Correlation between surface measurements, phase rms, and amplitude rms at different time scales are discussed. For 1 year, phase fluctuations at the DSN site in Goldstone, are better than 23 for 90 percent of the time (at 48.5 elevation). This data will be used to determine the suitability of the Goldstone site as a location for the Next Generation Deep Space Network.

  1. Preferential Flow Paths Allow Deposition of Mobile Organic Carbon Deep into Soil B Horizons

    NASA Astrophysics Data System (ADS)

    Marin-Spiotta, E.; Chadwick, O.; Kramer, M. G.

    2009-12-01

    Most of our understanding of soil carbon (C) dynamics derives from the top 10 to 20 cm, although globally the majority of the bulk soil C pool is found below those depths. Mineral associated C in deep soil is more stable than that held in surface horizons, and its long-term persistence may contribute to sequestration of anthropogenic C. Carbon can enter deep soil horizons in multiple ways: through biologically-mediated or abiotic physical mixing, illuviation, root inputs, or through a physical disturbance that would cause the burial of an originally shallow organic horizon. In this study, we investigated the role of dissolved organic matter (DOM) in the transport and stabilization of soil C in tropical rainforest volcanic soils, where high rainfall, a highly productive forest, and dominance of highly reactive, non-crystalline minerals contribute to large soil C stocks at depth with long mean residence times. DOM plays an important role in many biological and chemical processes in soils, including nutrient transfer within and across ecosystems. Carbon storage in these soils is linked to movement of both DOC and particulate organic C along infiltration pathways. Climate and soil mineralogical properties create the right conditions for C to be pumped from the organic horizons where microbial activity is highest, to deep mineral horizons, where the potential for stabilization is greatest. High rainfall preserves hydrated short-range order minerals that are subject to strong shrinkage during occasional drought periods. The resulting cracks in subsurface B horizons become pathways for DOM complexed with Fe and Al moving in soil solution during subsequent wet periods. Preferential flow of these organically rich solutes and/or colloids moves C to depth where C, Fe and Al are preferentially deposited on near-vertical crack surfaces and along near-horizonal flow surfaces at horizon boundaries. Long-term deposition forms discontinuous Fe- and OM-cemented lamella that serve to

  2. Signal level statistics and case studies for an over-the-horizon mid-Atlantic coastal link operating at C-band

    NASA Astrophysics Data System (ADS)

    Goldhirsh, Julius; Musiani, Bert H.

    1999-03-01

    We examine the results of 1 year of near-continuous measurements for a 128-km over-the-horizon C-band coastal propagation link. The link extends between Dam Neck, Virginia (16 km south of Virginia Beach), and Wallops Island, Virginia (approximately 150 km southeast of Washington, D. C.). The objectives of this effort are to explore the different mechanisms of propagation through an analysis of several case studies and to assess the statistical connectivity over the 1-year period. Case studies involving the linking of environmental information and measured signal levels are analyzed. Propagation factor levels due to evaporation ducts, surface ducts, and scattering from irregularities of the refractive index in the common volume are determined. Cumulative distributions of the measured propagation factor for the annual, fall-winter, and spring-summer periods are presented. Conditional and absolute distributions of propagation factor time durations are also presented and analyzed. It is demonstrated that during the spring-summer period, received signal levels were consistent with ducting and not with troposcatter. The fall-winter levels may be due to troposcatter from irregularities of the refractive index. The months giving the smallest and largest propagation factors were January and June, respectively.

  3. Projecting Program Cost Over an Adequate Time Horizon.

    ERIC Educational Resources Information Center

    Spencer, Milton

    Planning Programming Budgeting Systems involve the introduction of three major operational concepts. First, the development of an analytical capability to examine in depth both agency objectives and the various programs to meet these objectives. Second, the formation of a five-year planning and programming process combined with a sophisticated…

  4. Time horizon for AFV emission savings under Tier 2

    SciTech Connect

    Saricks, C. L.

    2000-03-20

    Implementation of the Federal Tier 2 vehicular emission standards according to the schedule presented in the December, 1999 Final Rule will result in substantial reductions of NMHC, CO, NO{sub x}, and fine particle emissions from motor vehicles. Currently, when compared to Tier 1 and even NLEV certification requirements, the emissions performance of automobiles and light-duty trucks powered by non-petroleum (especially, gaseous) fuels (i.e., vehicles collectively termed AFVs) enjoy measurable advantage over their gasoline- and diesel-fueled counterparts over the full Federal Test Procedure and, especially, in Bag 1 (cold start). For the lighter end of these vehicle classes, this advantage may disappear shortly after 2004 under the new standards, but should continue for a longer period (perhaps beyond 2008) for the heavier end as well as for heavy-duty vehicles relative to diesel-fueled counterparts. Because of the continuing commitment of the U.S. Department of Energy's Clean Cities coalitions to the acquisition and operation of AFVs of many types and size classes, it is important for them to know in which classes their acquisitions will remain clear relative to the petroleum-fueled counterparts they might otherwise procure. This paper provides an approximate timeline for and expected magnitude of such savings, assuming that full implementation of the Tier 2 standards covering both vehicular emissions and fuel sulfur limits proceeds on schedule. The pollutants of interest are primary ozone precursors and fine particulate matter from fuel combustion.

  5. Acceleration of a Static Observer Near the Event Horizon of a Static Isolated Black Hole.

    ERIC Educational Resources Information Center

    Doughty, Noel A.

    1981-01-01

    Compares the magnitude of the proper acceleration of a static observer in a static, isolated, spherically symmetric space-time region with the Newtonian result including the situation in the interior of a perfect-fluid star. This provides a simple physical interpretation of surface gravity and illustrates the global nature of the event horizon.…

  6. ALUMINUM PRECIPITATION AND DISSOLUTION RATES IN SPODOSOL BS HORIZONS IN THE NORTHEASTERN USA

    EPA Science Inventory

    The kinetics of Al precipitation/dissolution reactions in Spodosol Bs horizons from sites at Hubbard Brook, NH and Bear Brook, ME were examined. echanical vacuum extractor was employed to draw solutions through soil columns at solution/soil residence times between 0.3 and 100 h. ...

  7. 78 FR 54298 - Horizons ETFs Management (USA) LLC and Horizons ETF Trust; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-03

    .... Applicants currently intend that the initial series of the Trust will be the Horizons Active Global Dividend... through either the NSCC or DTC; or (ii) in the case of Funds holding non-U.S. investment (``Global Funds... holder of Shares of a Global Fund would be subject to unfavorable income tax treatment if the...

  8. Killing horizons around a uniformly accelerating and rotating particle

    SciTech Connect

    Farhoosh, H.; Zimmerman, R.L.

    1980-08-15

    The structure of the Killing horizon surrounding a uniformly accelerating and rotating particle which is emitting gravitational radiation is investigated. When expressed in terms of a coordinate system which is rigidly fixed to the particle undergoing uniform acceleration, the two inner horizons and ergoregion are similar to the horizons and ergoregion in the Kerr solution. These compact surfaces are distorted by the acceleration, being elongated in the forward direction and contracted in the backward direction. In addition to the two horizons that are similar to the Kerr solution, there is an additional noncompact horizon and an additional ergoregion which are caused by the acceleration. In general, the two ergoregions are disjoint, but as the acceleration parameter is sufficiently increased these ergoregions coalesce. A further increase of the acceleration will cause the two outer horizons to become degenerate and the ergoregion to vanish. An increase in the rotation parameter causes effects similar to those in the Kerr metric.

  9. Killing horizons around a uniformly accelerating and rotating particle

    NASA Astrophysics Data System (ADS)

    Farhoosh, Hamid; Zimmerman, Robert L.

    1980-08-01

    The structure of the Killing horizon surrounding a uniformly accelerating and rotating particle which is emitting gravitational radiation is investigated. When expressed in terms of a coordinate system which is rigidly fixed to the particle undergoing uniform acceleration, the two inner horizons and ergoregion are similar to the horizons and ergoregion in the Kerr solution. These compact surfaces are distorted by the acceleration, being elongated in the forward direction and contracted in the backward direction. In addition to the two horizons that are similar to the Kerr solution, there is an additional noncompact horizon and an additional ergoregion which are caused by the acceleration. In general, the two ergoregions are disjoint, but as the acceleration parameter is sufficiently increased these ergoregions coalesce. A further increase of the acceleration will cause the two outer horizons to become degenerate and the ergoregion to vanish. An increase in the rotation parameter causes effects similar to those in the Kerr metric.

  10. Gribov's horizon and the ghost dressing function

    SciTech Connect

    Boucaud, Ph.; Leroy, J. P.; Le Yaouanc, A.; Micheli, J.; Pene, O.; Rodriguez-Quintero, J.

    2009-11-01

    We study a relation recently derived by K. Kondo at zero momentum between the Zwanziger's horizon function, the ghost dressing function and Kugo's functions u and w. We agree with this result as far as bare quantities are considered. However, assuming the validity of the horizon gap equation, we argue that the solution w(0)=0 is not acceptable since it would lead to a vanishing renormalized ghost dressing function. On the contrary, when the cutoff goes to infinity, u(0){yields}{infinity}, w(0){yields}-{infinity} such that u(0)+w(0){yields}-1. Furthermore w and u are not multiplicatively renormalizable. Relaxing the gap equation allows w(0)=0 with u(0){yields}-1. In both cases the bare ghost dressing function, F(0,{lambda}), goes logarithmically to infinity at infinite cutoff. We show that, although the lattice results provide bare results not so different from the F(0,{lambda})=3 solution, this is an accident due to the fact that the lattice cutoffs lie in the range 1-3 GeV{sup -1}. We show that the renormalized ghost dressing function should be finite and nonzero at zero momentum and can be reliably estimated on the lattice up to powers of the lattice spacing; from published data on a 80{sup 4} lattice at {beta}=5.7 we obtain F{sub R}(0,{mu}=1.5 GeV){approx_equal}2.2.

  11. Energy and information near black hole horizons

    SciTech Connect

    Freivogel, Ben

    2014-07-01

    The central challenge in trying to resolve the firewall paradox is to identify excitations in the near-horizon zone of a black hole that can carry information without injuring a freely falling observer. By analyzing the problem from the point of view of a freely falling observer, I arrive at a simple proposal for the degrees of freedom that carry information out of the black hole. An infalling observer experiences the information-carrying modes as ingoing, negative energy excitations of the quantum fields. In these states, freely falling observers who fall in from infinity do not encounter a firewall, but freely falling observers who begin their free fall from a location close to the horizon are ''frozen'' by a flux of negative energy. When the black hole is ''mined,'' the number of information-carrying modes increases, increasing the negative energy flux in the infalling frame without violating the equivalence principle. Finally, I point out a loophole in recent arguments that an infalling observer must detect a violation of unitarity, effective field theory, or free infall.

  12. Cool horizons lead to information loss

    NASA Astrophysics Data System (ADS)

    Chowdhury, Borun D.

    2013-10-01

    There are two evidences for information loss during black hole evaporation: (i) a pure state evolves to a mixed state and (ii) the map from the initial state to final state is non-invertible. Any proposed resolution of the information paradox must address both these issues. The firewall argument focuses only on the first and this leads to order one deviations from the Unruh vacuum for maximally entangled black holes. The nature of the argument does not extend to black holes in pure states. It was shown by Avery, Puhm and the author that requiring the initial state to final state map to be invertible mandates structure at the horizon even for pure states. The proof works if black holes can be formed in generic states and in this paper we show that this is indeed the case. We also demonstrate how models proposed by Susskind, Papadodimas et al. and Maldacena et al. end up making the initial to final state map non-invertible and thus make the horizon "cool" at the cost of unitarity.

  13. Radiation from quantum weakly dynamical horizons in loop quantum gravity.

    PubMed

    Pranzetti, Daniele

    2012-07-01

    We provide a statistical mechanical analysis of quantum horizons near equilibrium in the grand canonical ensemble. By matching the description of the nonequilibrium phase in terms of weakly dynamical horizons with a local statistical framework, we implement loop quantum gravity dynamics near the boundary. The resulting radiation process provides a quantum gravity description of the horizon evaporation. For large black holes, the spectrum we derive presents a discrete structure which could be potentially observable. PMID:23031096

  14. Dynamical horizons: energy, angular momentum, fluxes, and balance laws.

    PubMed

    Ashtekar, Abhay; Krishnan, Badri

    2002-12-23

    Dynamical horizons are considered in full, nonlinear general relativity. Expressions of fluxes of energy and angular momentum carried by gravitational waves across these horizons are obtained. Fluxes are local, the energy flux is positive, and change in the horizon area is related to these fluxes. The flux formulas also give rise to balance laws analogous to the ones obtained by Bondi and Sachs at null infinity and provide generalizations of the first and second laws of black-hole mechanics. PMID:12484807

  15. Restricted psychological horizon in active methamphetamine users: future, past, probability, and social discounting

    PubMed Central

    Yi, Richard; Carter, Anne E.; Landes, Reid D.

    2014-01-01

    Methamphetamine users (MAU) exhibit an exaggerated bias for immediate rewards that reflects a restricted time horizon, where outcomes in the future are excessively discounted. An accumulating literature indicates that time in the future shares features with other dimensions of psychological distances including time in the past probability, and social distance, suggesting that bias for immediacy may be reducible to a more general restriction of psychological horizon. The purpose of the present study was to explore generalized restricted psychological horizon in active MAU by assessing future, past, probability, and social discounting. Compared with nonusing controls, MAU preferred psychologically proximal outcomes, resulting in higher rates for all types of discounting, which supports the conceptualization that MAU insufficiently integrate outcomes of psychological distance (i.e. in the future, the past, probabilistic, for others) into the valuation of current behavioral alternatives. The present results are suggestive of a more fundamental process of problematic decision-making associated with methamphetamine use, indicating the necessity of more comprehensive approaches to address the generalized limitations of restricted psychological horizon. PMID:22743602

  16. Gravitational anomaly and Hawking radiation near a weakly isolated horizon

    SciTech Connect

    Wu Xiaoning; Huang Chaoguang; Sun Jiarui

    2008-06-15

    Based on the idea of the work by Wilczek and his collaborators, we consider the gravitational anomaly near a weakly isolated horizon. We find that there exists a universal choice of tortoise coordinate for any weakly isolated horizon. Under this coordinate, the leading behavior of a quite arbitrary scalar field near a horizon is a 2-dimensional chiral scalar field. This means we can extend the idea of Wilczek and his collaborators to more general cases and show the relation between gravitational anomaly and Hawking radiation is a universal property of a black hole horizon.

  17. Gravitational anomaly and Hawking radiation near a weakly isolated horizon

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoning; Huang, Chao-Guang; Sun, Jia-Rui

    2008-06-01

    Based on the idea of the work by Wilczek and his collaborators, we consider the gravitational anomaly near a weakly isolated horizon. We find that there exists a universal choice of tortoise coordinate for any weakly isolated horizon. Under this coordinate, the leading behavior of a quite arbitrary scalar field near a horizon is a 2-dimensional chiral scalar field. This means we can extend the idea of Wilczek and his collaborators to more general cases and show the relation between gravitational anomaly and Hawking radiation is a universal property of a black hole horizon.

  18. Into the Kuiper Belt: New Horizons Post-Pluto

    NASA Astrophysics Data System (ADS)

    Harrison Parker, Alex; Spencer, John; Benecchi, Susan; Binzel, Richard; Borncamp, David; Buie, Marc; Fuentes, Cesar; Gwyn, Stephen; Kavelaars, JJ; Noll, Keith; Petit, Jean-Marc; Porter, Simon; Showalter, Mark; Stern, S. Alan; Sterner, Ray; Tholen, David; Verbiscer, Anne; Weaver, Hal; Zangari, Amanda

    2015-11-01

    New Horizons is now beyond Pluto and flying deeper into the Kuiper Belt. In the summer of 2014, a Hubble Space Telescope Large Program identified two candidate Cold Classical Kuiper Belt Objects (KBOs) that were within reach of New Horizons' remaining fuel budget. Here we present the selection of the Kuiper Belt flyby target for New Horizons' post-Pluto mission, our state of knowledge regarding this target and the potential 2019 flyby, the status of New Horizons' targeting maneuver, and prospects for near-future long-range observations of other KBOs.

  19. Criticality and surface tension in rotating horizon thermodynamics

    NASA Astrophysics Data System (ADS)

    Hansen, Devin; Kubizňák, David; Mann, Robert B.

    2016-08-01

    We study a modified horizon thermodynamics and the associated criticality for rotating black hole spacetimes. Namely, we show that under a virtual displacement of the black hole horizon accompanied by an independent variation of the rotation parameter, the radial Einstein equation takes a form of a ‘cohomogeneity two’ horizon first law, δ E=Tδ S+{{Ω }}δ J-σ δ A, where E and J are the horizon energy (an analogue of the Misner–Sharp mass) and the horizon angular momentum, Ω is the horizon angular velocity, A is the horizon area, and σ is the surface tension induced by the matter fields. For fixed angular momentum, the above equation simplifies and the more familiar (cohomogeneity one) horizon first law δ E=Tδ S-Pδ V is obtained, where P is the pressure of matter fields and V is the horizon volume. A universal equation of state is obtained in each case and the corresponding critical behavior is studied.

  20. Infectious complications more than 1 year after liver transplantation: a 3-decade nationwide experience.

    PubMed

    Aberg, F; Mäkisalo, H; Höckerstedt, K; Isoniemi, H

    2011-02-01

    Because few reports have addressed infections late (≥1 year) after liver transplantation (LT), we evaluated the incidence, risk factors and pathogens involved. Infection data were from the Finnish LT registry, with starting date, type and relevant pathogens for 501 Finnish adult LT patients surviving ≥1 year post-transplant. Follow-up end points were end of study, death or retransplantation. Logistic regression to assess risk factors was adjusted for age, gender and follow-up time. With 3923 person-years of follow-up, overall infection incidence was 66/1000 person-years; 155 (31%) suffered 259 infections, and two-thirds experienced only one infection. Cholangitis (20%), pneumonia (19%) and sepsis (14%) were most common. The most frequent bacteria were Enterococcus spp. and Escherichia coli, and the most frequent viruses cytomegalovirus and varicella zoster virus. Fungal infections were rare (n = 7). With 13 fatal infections, 17% of all late deaths involved infection. Primary sclerosing cholangitis (PSC) and Roux-en-Y-type biliary anastomosis were associated with cholangitis; 18% of PSC patients suffered late cholangitis. Late acute rejection was associated with sepsis. Age, gender or cytomegalovirus did not significantly influence late infections. In conclusion, although infection risk under maintenance immunosuppression therapy is relatively low, particular vigilance regarding cholangitis, pneumonia and sepsis seems appropriate. PMID:21219571

  1. Perturbations of the Kerr spacetime in horizon-penetrating coordinates

    NASA Astrophysics Data System (ADS)

    Campanelli, Manuela; Khanna, Gaurav; Laguna, Pablo; Pullin, Jorge; Ryan, Michael P.

    2001-04-01

    We derive the Teukolsky equation for perturbations of a Kerr spacetime when the spacetime metric is written in either ingoing or outgoing Kerr-Schild form. We also write explicit formulae for setting up the initial data for the Teukolsky equation in the time domain in terms of a 3-metric and an extrinsic curvature. The motivation of this work is to have in place a formalism to study the evolution in the `close limit' of two recently proposed solutions to the initial-value problem in general relativity that are based on Kerr-Schild slicings. A perturbative formalism in horizon-penetrating coordinates is also very desirable in connection with numerical relativity simulations using black hole `excision'.

  2. The atmosphere of Pluto as observed by New Horizons

    NASA Astrophysics Data System (ADS)

    Gladstone, G. Randall; Stern, S. Alan; Ennico, Kimberly; Olkin, Catherine B.; Weaver, Harold A.; Young, Leslie A.; Summers, Michael E.; Strobel, Darrell F.; Hinson, David P.; Kammer, Joshua A.; Parker, Alex H.; Steffl, Andrew J.; Linscott, Ivan R.; Parker, Joel Wm.; Cheng, Andrew F.; Slater, David C.; Versteeg, Maarten H.; Greathouse, Thomas K.; Retherford, Kurt D.; Throop, Henry; Cunningham, Nathaniel J.; Woods, William W.; Singer, Kelsi N.; Tsang, Constantine C. C.; Schindhelm, Eric; Lisse, Carey M.; Wong, Michael L.; Yung, Yuk L.; Zhu, Xun; Curdt, Werner; Lavvas, Panayotis; Young, Eliot F.; Tyler, G. Leonard; Bagenal, F.; Grundy, W. M.; McKinnon, W. B.; Moore, J. M.; Spencer, J. R.; Andert, T.; Andrews, J.; Banks, M.; Bauer, B.; Bauman, J.; Barnouin, O. S.; Bedini, P.; Beisser, K.; Beyer, R. A.; Bhaskaran, S.; Binzel, R. P.; Birath, E.; Bird, M.; Bogan, D. J.; Bowman, A.; Bray, V. J.; Brozovic, M.; Bryan, C.; Buckley, M. R.; Buie, M. W.; Buratti, B. J.; Bushman, S. S.; Calloway, A.; Carcich, B.; Conard, S.; Conrad, C. A.; Cook, J. C.; Cruikshank, D. P.; Custodio, O. S.; Ore, C. M. Dalle; Deboy, C.; Dischner, Z. J. B.; Dumont, P.; Earle, A. M.; Elliott, H. A.; Ercol, J.; Ernst, C. M.; Finley, T.; Flanigan, S. H.; Fountain, G.; Freeze, M. J.; Green, J. L.; Guo, Y.; Hahn, M.; Hamilton, D. P.; Hamilton, S. A.; Hanley, J.; Harch, A.; Hart, H. M.; Hersman, C. B.; Hill, A.; Hill, M. E.; Holdridge, M. E.; Horanyi, M.; Howard, A. D.; Howett, C. J. A.; Jackman, C.; Jacobson, R. A.; Jennings, D. E.; Kang, H. K.; Kaufmann, D. E.; Kollmann, P.; Krimigis, S. M.; Kusnierkiewicz, D.; Lauer, T. R.; Lee, J. E.; Lindstrom, K. L.; Lunsford, A. W.; Mallder, V. A.; Martin, N.; McComas, D. J.; McNutt, R. L.; Mehoke, D.; Mehoke, T.; Melin, E. D.; Mutchler, M.; Nelson, D.; Nimmo, F.; Nunez, J. I.; Ocampo, A.; Owen, W. M.; Paetzold, M.; Page, B.; Pelletier, F.; Peterson, J.; Pinkine, N.; Piquette, M.; Porter, S. B.; Protopapa, S.; Redfern, J.; Reitsema, H. J.; Reuter, D. C.; Roberts, J. H.; Robbins, S. J.; Rogers, G.; Rose, D.; Runyon, K.; Ryschkewitsch, M. G.; Schenk, P.; Sepan, B.; Showalter, M. R.; Soluri, M.; Stanbridge, D.; Stryk, T.; Szalay, J. R.; Tapley, M.; Taylor, A.; Taylor, H.; Umurhan, O. M.; Verbiscer, A. J.; Versteeg, M. H.; Vincent, M.; Webbert, R.; Weidner, S.; Weigle, G. E.; White, O. L.; Whittenburg, K.; Williams, B. G.; Williams, K.; Williams, S.; Zangari, A. M.; Zirnstein, E.

    2016-03-01

    Observations made during the New Horizons flyby provide a detailed snapshot of the current state of Pluto's atmosphere. Whereas the lower atmosphere (at altitudes of less than 200 kilometers) is consistent with ground-based stellar occultations, the upper atmosphere is much colder and more compact than indicated by pre-encounter models. Molecular nitrogen (N2) dominates the atmosphere (at altitudes of less than 1800 kilometers or so), whereas methane (CH4), acetylene (C2H2), ethylene (C2H4), and ethane (C2H6) are abundant minor species and likely feed the production of an extensive haze that encompasses Pluto. The cold upper atmosphere shuts off the anticipated enhanced-Jeans, hydrodynamic-like escape of Pluto's atmosphere to space. It is unclear whether the current state of Pluto's atmosphere is representative of its average state - over seasonal or geologic time scales.

  3. The atmosphere of Pluto as observed by New Horizons.

    PubMed

    Gladstone, G Randall; Stern, S Alan; Ennico, Kimberly; Olkin, Catherine B; Weaver, Harold A; Young, Leslie A; Summers, Michael E; Strobel, Darrell F; Hinson, David P; Kammer, Joshua A; Parker, Alex H; Steffl, Andrew J; Linscott, Ivan R; Parker, Joel Wm; Cheng, Andrew F; Slater, David C; Versteeg, Maarten H; Greathouse, Thomas K; Retherford, Kurt D; Throop, Henry; Cunningham, Nathaniel J; Woods, William W; Singer, Kelsi N; Tsang, Constantine C C; Schindhelm, Eric; Lisse, Carey M; Wong, Michael L; Yung, Yuk L; Zhu, Xun; Curdt, Werner; Lavvas, Panayotis; Young, Eliot F; Tyler, G Leonard

    2016-03-18

    Observations made during the New Horizons flyby provide a detailed snapshot of the current state of Pluto's atmosphere. Whereas the lower atmosphere (at altitudes of less than 200 kilometers) is consistent with ground-based stellar occultations, the upper atmosphere is much colder and more compact than indicated by pre-encounter models. Molecular nitrogen (N2) dominates the atmosphere (at altitudes of less than 1800 kilometers or so), whereas methane (CH4), acetylene (C2H2), ethylene (C2H4), and ethane (C2H6) are abundant minor species and likely feed the production of an extensive haze that encompasses Pluto. The cold upper atmosphere shuts off the anticipated enhanced-Jeans, hydrodynamic-like escape of Pluto's atmosphere to space. It is unclear whether the current state of Pluto's atmosphere is representative of its average state--over seasonal or geologic time scales. PMID:26989258

  4. Learn to Change: Teaching Toward a Shifting Health Care Horizon.

    PubMed

    Hart, Laura C

    2016-01-01

    Changes in health care-including a growing emphasis on quality, outcomes, and lower costs-are transforming the delivery of care and creating a knowledge gap that continuing education must bridge. As clinicians and health leaders spend less time in hospital settings, educational activities are likely to extend their reach, for instance through online education distributed on laptops, tablets, or smartphones. Ezekiel J. Emanuel, MD, PhD, explored this shift in his 2016 keynote to the World Congress for Continuing Professional Development: "Learn to Change: Teaching Toward a Shifting Health Care Horizon." This article describes some of the main trends in health care that Dr. Emanuel foresees, focusing on the implications of the changing role of hospitals for innovation in continuing education. PMID:27584062

  5. Attitude Determination by Using Horizon and Sun Sensors

    NASA Technical Reports Server (NTRS)

    Huang, Allen K. H.; French, Larry A.

    1993-01-01

    The Pointing and Alignment Workstation (PAWS) developed by Teledyne Brown Engineering (TBE) has successfully supported the first and second Atmospheric Laboratory for Applications and Science (ATLAS 1, 2) spacelab missions for NASA. The primary PAWS objective was to provide realtime pointing information to instruments whose line of-sight is dependent on Shuttle attitude and to study/quantify the causes and effects of Shuttle and payload pointing errors. In addition to Shuttle IMU attitude information, PAWS used atmospheric science sensors data to determine the spacecraft attitude. PAWS successfully achieved these goals by acquiring and processing data during the ATLAS 1, 2 mission. This paper presents the attitude determination algorithm real time processing, and results of post mission analysis. The findings of this study include the quality of the horizon sensor and IMU measurements as well as accuracy of attitude processor algorithm.

  6. Shoreline oiling from the Deepwater Horizon oil spill.

    PubMed

    Nixon, Zachary; Zengel, Scott; Baker, Mary; Steinhoff, Marla; Fricano, Gail; Rouhani, Shahrokh; Michel, Jacqueline

    2016-06-15

    We build on previous work to construct a comprehensive database of shoreline oiling exposure from the Deepwater Horizon (DWH) spill by compiling field and remotely-sensed datasets to support oil exposure and injury quantification. We compiled a spatial database of shoreline segments with attributes summarizing habitat, oiling category and timeline. We present new simplified oil exposure classes for both beaches and coastal wetland habitats derived from this database integrating both intensity and persistence of oiling on the shoreline over time. We document oiling along 2113km out of 9545km of surveyed shoreline, an increase of 19% from previously published estimates and representing the largest marine oil spill in history by length of shoreline oiled. These data may be used to generate maps and calculate summary statistics to assist in quantifying and understanding the scope, extent, and spatial distribution of shoreline oil exposure as a result of the DWH incident. PMID:27098990

  7. Near-horizon geometry and warped conformal symmetry

    NASA Astrophysics Data System (ADS)

    Afshar, Hamid; Detournay, Stéphane; Grumiller, Daniel; Oblak, Blagoje

    2016-03-01

    We provide boundary conditions for three-dimensional gravity including boosted Rindler spacetimes, representing the near-horizon geometry of non-extremal black holes or flat space cosmologies. These boundary conditions force us to make some unusual choices, like integrating the canonical boundary currents over retarded time and periodically identifying the latter. The asymptotic symmetry algebra turns out to be a Witt algebra plus a twisted u(1) current algebra with vanishing level, corresponding to a twisted warped CFT that is qualitatively different from the ones studied so far in the literature. We show that this symmetry algebra is related to BMS by a twisted Sugawara construction and exhibit relevant features of our theory, including matching micro- and macroscopic calculations of the entropy of zero-mode solutions. We confirm this match in a generalization to boosted Rindler-AdS. Finally, we show how Rindler entropy emerges in a suitable limit.

  8. Regenerative PN ranging experience with New Horizons during 2012

    NASA Astrophysics Data System (ADS)

    Jensen, J. R.; Haskins, C. B.; DeBoy, C. C.

    The New Horizons mission to Pluto is the first deep space mission to include the capability of supporting regenerative PN ranging. During the current phase of the mission, sequential tone ranging supports the mission navigation requirements but regenerative ranging will expand the conditions (antenna selection, integration time, etc.) over which ranging will be successful during any extended mission following the Pluto fly-by, to objects in the Kuiper belt. Experience with regenerative ranging is being obtained now in preparation for its use in an extended mission. During most of 2012, New Horizons was in a hibernation state. Tracking was conducted between late April and early July. Six regenerative ranging passes were performed to bookend this interval; 2 at the beginning and 4 at the end. During that time, the distance between the spacecraft and Earth was in excess of 22 Astronautical Units (AU) and the Pr/No levels were below 15 dB-Hz. A seventh regenerative ranging pass was performed in May at a higher signal level in order to test the acquisition of the ranging code by the spacecraft during a variety of conditions. The consistency of the regenerative range measurements with the adjacent sequential tone ranging measurements has been demonstrated and serves as a check on the calibration of the regenerative ranging system conditions. The range measurement precision has been shown to follow the predictions that are based on the uplink and downlink signal power. The regenerative ranging system has been shown to acquire the uplink ranging code with and without a commanded reset and regardless of the noise bandwidth setting of the system. This paper will present the data that was obtained during 2012 and will describe the analysis results for the regenerative ranging experience during 2012.

  9. A longitudinal study of back dimension changes over 1 year in sports horses.

    PubMed

    Greve, Line; Dyson, Sue

    2015-01-01

    Major back dimension changes over time have been observed in some horses, the speed of which may be influenced by work type, skeletal maturity, nutrition and saddle fit. Currently, there are no longitudinal data quantifying changes in back dimensions. The objectives of this study were to quantify back dimension changes over time, to identify the effects of horse, saddle and rider on these dimensions, and to determine their association with season, weight, work and saddle management. A prospective, longitudinal study was performed, using stratified random sampling within a convenience sample of 104 sports horses in normal work. Thoracolumbar dimensions/symmetry were measured at predetermined sites every second month over 1 year; weight, work and saddle management changes were recorded. Descriptive statistics, and univariable and multiple mixed effects linear regression were performed to assess the association between management changes, horse-saddle-rider factors and back dimension changes. Complete data was available for 63/104 horses, including horses used for dressage (n= 26), showjumping (n= 26), eventing (n= 26) and general purpose (n= 26), with age groups 3-5 years (n = 24), 6-8 years (n = 28), 9-12 years (n = 24) and ≥ 13 years (n = 28). There were considerable variations in back dimensions over 1 year. In the multivariable analysis, the presence of gait abnormalities at initial examination and back asymmetry were significant and had a negative effect on changes in back dimensions. Subsequent improved saddle fit, similar or increased work intensity, season (summer versus winter) and increased bodyweight retained significance, having positive effects on changes in back dimensions. In conclusion, quantifiable changes in back dimensions occur throughout the year. Saddle fit should be reassessed professionally several times a year, especially if there has been a change in work intensity. PMID:25510314

  10. Horizon sensors attitude errors simulation for the Brazilian Remote Sensing Satellite

    NASA Astrophysics Data System (ADS)

    Vicente de Brum, Antonio Gil; Ricci, Mario Cesar

    Remote sensing, meteorological and other types of satellites require an increasingly better Earth related positioning. From the past experience it is well known that the thermal horizon in the 15 micrometer band provides conditions of determining the local vertical at any time. This detection is done by horizon sensors which are accurate instruments for Earth referred attitude sensing and control whose performance is limited by systematic and random errors amounting about 0.5 deg. Using the computer programs OBLATE, SEASON, ELECTRO and MISALIGN, developed at INPE to simulate four distinct facets of conical scanning horizon sensors, attitude errors are obtained for the Brazilian Remote Sensing Satellite (the first one, SSR-1, is scheduled to fly in 1996). These errors are due to the oblate shape of the Earth, seasonal and latitudinal variations of the 15 micrometer infrared radiation, electronic processing time delay and misalignment of sensor axis. The sensor related attitude errors are thus properly quantified in this work and will, together with other systematic errors (for instance, ambient temperature variation) take part in the pre-launch analysis of the Brazilian Remote Sensing Satellite, with respect to the horizon sensor performance.

  11. Landsat-4 horizon scanner flight performance

    NASA Technical Reports Server (NTRS)

    Bilanow, S.; Chen, L. C.

    1984-01-01

    This paper presents an analysis of the flight data from a new design of horizon scanner flown on Landsat-4. The salient features in the data are described and demonstrated by data plots. High frequency noise must be filtered out to achieve good accuracy, but this is effectively done by 128-point averaging. Sun and moon interference effects are identified. The effects of earth oblateness and spacecraft altitude variations are modeled, and the residual systematic errors are analyzed. Most of the residual errors are apparently explained by the effects of earth radiance variation, with the winter polar regions showing the highest variability in the attitude measurements due to winter stratosphere temperature variations. In general, this sensor provides improved accuracy over those flown on previous missions.

  12. Black Hole Observations - Towards the Event Horizon

    NASA Astrophysics Data System (ADS)

    Britzen, Silke

    Black Holes are probably the most elusive solutions of Einstein's theory of General Relativity. Despite numerous observations of the direct galactic environment and indirect influence of astrophysical black holes (e.g. jets, variable emission across the wavelength spectrum, feedback processes, etc.) -- a direct proof of their existence is still lacking. This article highlights some aspects deduced from many observations and concentrates on the experimental results with regard to black holes with masses from millions to billions of solar masses. The focus will be on the challenges and remaining questions. The Event Horizon Telescopce (EHT) project to image the photon sphere of Sgr A* and its potential is briefly sketched. This instrumental approach shall lead to highest resolution observations of the supermassive black hole at the center of the Milky Way (Sgr A*).

  13. Horizon complementarity in elliptic de Sitter space

    NASA Astrophysics Data System (ADS)

    Hackl, Lucas; Neiman, Yasha

    2015-02-01

    We study a quantum field in elliptic de Sitter space dS4/Z2—the spacetime obtained from identifying antipodal points in dS4. We find that the operator algebra and Hilbert space cannot be defined for the entire space, but only for observable causal patches. This makes the system into an explicit realization of the horizon complementarity principle. In the absence of a global quantum theory, we propose a recipe for translating operators and states between observers. This translation involves information loss, in accordance with the fact that two observers see different patches of the spacetime. As a check, we recover the thermal state at the de Sitter temperature as a state that appears the same to all observers. This thermal state arises from the same functional that, in ordinary dS4, describes the Bunch-Davies vacuum.

  14. Opportunity Spies 'Endurance' on the Horizon

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image taken by the Mars Exploration Rover Opportunity's panoramic camera shows the eastern plains that stretch beyond the small crater where the rover landed. In the distance, the rim of a larger crater dubbed 'Endurance' can be seen.

    This color mosaic was taken on the 32nd martian day, or sol, of the rover's mission and spans 20 degrees of the horizon. It was taken while Opportunity was parked at the north end of the outcrop, in front of the rock region dubbed 'El Capitan' and facing east.

    The features seen at the horizon are the near and far rims of 'Endurance,' the largest crater within about 6 kilometers (4 miles) of the lander. Using orbital data from the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, scientists estimated the crater to be 160 meters (175 yards) in diameter, and about 720 meters (half a mile) away from the lander.

    The highest point visible on 'Endurance' is the highest point on the far wall of the crater; the sun is illuminating the inside of the far wall.

    Between the location where the image was taken at 'El Capitan' and 'Endurance' are the flat, smooth Meridiani plains, which scientists believe are blanketed in the iron-bearing mineral called hematite. The dark horizontal feature near the bottom of the picture is a small, five-meter (16-feet) crater, only 50 meters (164 feet) from Opportunity's present position. When the rover leaves the crater some 2 to 3 weeks from now, 'Endurance' is one of several potential destinations.

  15. Air-shower spectroscopy at horizons

    NASA Astrophysics Data System (ADS)

    Fargion, D.

    2006-07-01

    Downward cosmic rays are mostly revealed on the ground by their air-showers diluted and filtered secondary μμ traces and/or by their (Cerenkov - Fluorescent) light because of the high altitude numerous and luminous electromagnetic ee,γ shower component. Horizontal and upward air-showers are even more suppressed by deeper atmosphere opacity and by the Earth shadows. In such noise-free horizontal and upward directions rare Ultra High Cosmic rays and rarer neutrino induced air-showers may shine, mostly mediated by resonant PeV ν¯+e→W interactions in air or by higher energy tau air-showers originated by ν skimming the Earth. At high altitude (mountains, planes, balloons) the air density is so rarefied that nearly all common air-showers might be observed at their maximal growth at a tuned altitude and direction. The arrival angle samples different distances and the corresponding most probable primary cosmic ray energy. The larger and larger distances (between observer and C.R. interaction) make wider and wider the shower area and it enlarges the probability of being observed (up to three orders of magnitude more than vertical showers); the observation of a maximal electromagnetic shower development may amplify the signal by two three orders of magnitude (with respect to a suppressed shower at sea level); the peculiar altitude angle range (ten twenty km height and ≃80 90 zenith angle) may disentangle at best the primary cosmic ray energy and composition. Even from existing mountain observatories the up-going air-showers may trace, above the horizons, PeV EeV high energy cosmic rays and, below the horizons, PeV EeV neutrino astronomy: their early signals may be captured in already existing gamma telescopes such as Magic at Canarie, while facing the Earth edges during (useless) cloudy nights.

  16. THERMAL CONDUCTIVITY OF THE POTENTIAL REPOSITORY HORIZON

    SciTech Connect

    J.E. BEAN

    2004-09-27

    The primary purpose of this report is to assess the spatial variability and uncertainty of bulk thermal conductivity in the host horizon for the repository at Yucca Mountain. More specifically, the lithostratigraphic units studied are located within the Topopah Spring Tuff (Tpt) and consist of the upper lithophysal zone (Tptpul), the middle nonlithophysal zone (Tptpmn), the lower lithophysal zone (Tptpll), and the lower nonlithophysal zone (Tptpln). Design plans indicate that approximately 81 percent of the repository will be excavated in the Tptpll, approximately 12 percent in the Tptpmn, and the remainder in the Tptul and Tptpln (BSC 2004 [DIRS 168370]). This report provides three-dimensional geostatistical estimates of the bulk thermal conductivity for the four stratigraphic layers of the repository horizon. The three-dimensional geostatistical estimates of matrix and lithophysal porosity, dry bulk density, and matrix thermal conductivity are also provided. This report provides input to various models and calculations that simulate heat transport through the rock mass. These models include the ''Drift Degradation Analysis, Multiscale Thermohydrologic Model, Ventilation Model and Analysis Report, Igneous Intrusion Impacts on Waste Packages and Waste Forms, Drift-Scale Coupled Processes (DST and TH Seepage) Models'', and ''Drift Scale THM Model''. These models directly or indirectly provide input to the total system performance assessment (TSPA). The main distinguishing characteristic among the lithophysal and nonlithophysal units is the percentage of large-scale (centimeters-meters) voids within the rock. The Tptpul and Tptpll, as their names suggest, have a higher percentage of lithophysae than the Tptpmn and the Tptpln. Understanding the influence of the lithophysae is of great importance to understanding bulk thermal conductivity.

  17. Whooping cough in South-East Romania: a 1-year study.

    PubMed

    Dinu, Sorin; Guillot, Sophie; Dragomirescu, Cristiana Cerasella; Brun, Delphine; Lazăr, Stefan; Vancea, Geta; Ionescu, Biatrice Mariana; Gherman, Mariana Felicia; Bjerkestrand, Andreea-Florina-Dana; Ungureanu, Vasilica; Guiso, Nicole; Damian, Maria

    2014-03-01

    The incidence of whooping cough in Romania is substantially underestimated, and, as noted by the health authorities, this is mostly due to the lack of both awareness and biological diagnosis. We conducted a 1-year study in Bucharest in order to assess the circulation of Bordetella pertussis, the main etiological agent of whooping cough. Fifty-one subjects suspected of whooping cough were enrolled. Culture, real-time PCR, and enzyme-linked immunosorbent assay were used for laboratory diagnosis. Whooping cough patients (63%) were distributed among all age groups, and most were unvaccinated, incompletely vaccinated, or had been vaccinated more than 5 years previously. Bordetella holmesii DNA was detected in 22% of the bordetellosis cases; these patients included adults; teenagers; and, surprisingly, young children. B. pertussis isolates were similar to the clinical isolates currently circulating elsewhere in Europe. One isolate does not express pertactin, an antigen included in some acellular pertussis vaccines. PMID:24355701

  18. [Interferon beta 1-a in multiple sclerosis: 1-year experience in 62 patients].

    PubMed

    Tilbery, C P; Felipe, E; Moreira, M A; Mendes, M F; França, A S

    2000-06-01

    We report the results of a trial of interferon beta 1-a in 62 ambulatory patients with relapsing-remitting multiple sclerosis. Entry criteria included EDSS of 0 to 5.5 and at least two exacerbations in the previous 2 years. The patients received 3 million international units by subcutaneous injections three times a week. The end points were differences in exacerbation rate and treatment effect on disease progression. The annual exacerbation rate for patients that did not take the interferon beta 1-a was 1.32 and for the patients under medication 0.63. The EDSS score in patients that did not take the mediaction was 4.7 and 2.0 for the patients with interferon beta 1-a. Interferon beta 1-a was well tolerated and 85% of patients completed 1 year treatment. PMID:10920406

  19. New Horizons Risk Communication Strategy, Planning, Implementation, and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Dawson, Sandra A.

    2006-01-01

    This paper discusses the risk communication goals, strategy, planning process and product development for the New Horizons mission, including lessons from the Cassini mission that were applied in that effort, and presents lessons learned from the New Horizons effort that could be applicable to future missions.

  20. The Horizon Report: 2010 Australia-New Zealand Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Smith, R.; Levine, A.; Haywood, K.

    2010-01-01

    The internationally recognized series of "Horizon Reports" is part of the New Media Consortium's Horizon Project, a comprehensive research venture established in 2002 that identifies and describes emerging technologies likely to have a large impact over the coming five years on a variety of sectors around the globe. This volume, the "2010 Horizon…

  1. The NMC Horizon Report: 2013 Higher Education Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Adams Becker, S.; Cummins, M.; Estrada, V.; Freeman, A.; Ludgate, H.

    2013-01-01

    The internationally recognized "NMC Horizon Report" series and regional "NMC Technology Outlooks" are part of the NMC Horizon Project, a comprehensive research venture established in 2002 that identifies and describes emerging technologies likely to have a large impact over the coming five years in education around the globe.…

  2. The NMC Horizon Report: 2013 K-12 Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Adams Becker, S.; Cummins, M.; Estrada V.; Freeman, A.; Ludgate, H.

    2013-01-01

    "The NMC Horizon Report" series is the most visible outcome of the New Media Consortium (NMC) Horizon Project, an ongoing research effort established in 2002 that identifies and describes emerging technologies likely to have a large impact on teaching, learning, research, or creative expression within education around the globe. This…

  3. The NMC Horizon Report: 2012 Higher Education Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Adams, S.; Cummins, M.

    2012-01-01

    The internationally recognized "NMC Horizon Report" series and regional "NMC Technology Outlooks" are part of the NMC Horizon Project, a comprehensive research venture established in 2002 that identifies and describes emerging technologies likely to have a large impact over the coming five years in education around the globe. This volume, the "NMC…

  4. A Fusion of Horizons: Students' Encounters with "Will and Wave"

    ERIC Educational Resources Information Center

    Myers, James L.

    2006-01-01

    In a case study, I applied philosophical hermeneutic principles in an advanced level EFL writing class in Taiwan. A "fusion of horizons" occurs at the junction of two intertwined interpretations: one from our socio-historical tradition and the other from our experience of novel phenomena. I explored students' hermeneutic horizons in relation to…

  5. The NMC Horizon Report: 2011 K-12 Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Adams, S.; Haywood, K.

    2011-01-01

    "The NMC Horizon Report" series is the most visible outcome of the New Media Consortium. (NMC) Horizon Project, an ongoing research effort established in 2002 that identifies and describes emerging technologies likely to have a large impact on teaching, learning, research, or creative expression within education around the globe. This volume, "The…

  6. NEW JERSEY APPROACH TO OUTERBRIDGE CROSSING BRIDGE, NOTE DISTANT HORIZON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    NEW JERSEY APPROACH TO OUTERBRIDGE CROSSING BRIDGE, NOTE DISTANT HORIZON NEW YORK SKYLINE AND ALMOST IN THE MIDDLE OF THE HORIZON THE TWIN TOWERS OF THE VERRAZANO-NARROWS BRIDGE - Outerbridge Crossing Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

  7. The NMC Horizon Report: 2015 Higher Education Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Adams Becker, S.; Estrada, V.; Freeman, A.

    2015-01-01

    The "NMC Horizon Report: 2015 Higher Education Edition" is a collaborative effort between the New Media Consortium (NMC) and the EDUCAUSE Learning Initiative (ELI). This 12th edition describes annual findings from the NMC Horizon Project, an ongoing research project designed to identify and describe emerging technologies likely to have…

  8. The NMC Horizon Report: 2014 K-12 Edition

    ERIC Educational Resources Information Center

    Johnson, L.; Adams Becker, S.; Estrada, V.; Freeman, A.

    2014-01-01

    "The NMC Horizon Report" series is the most visible outcome of the New Media Consortium (NMC) Horizon Project, an ongoing research effort established in 2002 that identifies and describes emerging technologies likely to have a large impact on teaching, learning, research, or creative expression within every sector of education in some 65…

  9. Temporal trends in microbial abundance and biodegradation in Louisiana salt marshes following the Deepwater Horizon oil spill

    NASA Astrophysics Data System (ADS)

    Mahmoudi, N.; Fulthorpe, R. R.; Zimmerman, A. R.; Silliman, B. R.; Slater, G. F.

    2012-12-01

    The Deepwater Horizon oil spill that began in April 2010 released approximately 4.9 million barrels of crude oil into the Gulf of Mexico waters. Coastal salt marshes experienced moderate to heavy oiling as spilled oils washed ashore and threatened economically important habitats. In situ biodegradation of petroleum by microbes is one of the most effective methods used to remediate oil spills. However, demonstrating biodegradation can be challenging due to heterogeneous distributions of contaminants and dynamic conditions of coastal ecosystems. Salt marshes provide a unique opportunity in which variations in the natural abundance of δ13C can be used to confirm in situ biodegradation of petroleum. Marsh grasses, specifically Spartina sp., have δ13C values of -12 to -14‰ whereas the BP crude oil has a δ13C signature of -27‰. Thus, the 13C content of microbial membrane lipids (which reflects their carbon source) can be used to detect incorporation of petroleum-derived carbon. We investigated biodegradation in marsh sediments in oiled and non-oiled portions of Barataria Bay, Louisiana which experienced some of the most extensive oil contamination. Samples were collected 3, 9 and 15 months following Deepwater Horizon oil intrusion to assess biodegradation over time. Total alkane and PAH analyses confirmed that by Oct 2011 (15 months), concentrations had been significantly reduced (by up to 50,000 ug/kg at some sites). Microbial phospholipid fatty acids (PLFA) analysis revealed that cell densities decreased over the 1 year sampling period across both oil-impacted and non-impacted sites indicating that, rather than petroleum presence, seasonal variability was likely the primary control on microbial abundance. The ranges of δ13C PLFA values in oil-impacted (-26.7 to -30.5‰ ± 1.0) and non-impacted sediments (-24.5 to -33.3‰ ± 0.7) in Oct 2010 overlap, thereby reducing confidence in confirmation of biodegradation at this time point. However, in Oct 2011, PLFA

  10. Fluctuations in horizon-fluid lead to negative bulk viscosity

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Swastik; Shankaranarayanan, S.

    2016-03-01

    Einstein equations projected on to a black-hole horizon give rise to Navier-Stokes equations. Horizon-fluids typically possess unusual features like negative bulk viscosity, and it is not clear whether a statistical-mechanical description exists for such fluids. In this work, we provide an explicit derivation of the Bulk viscosity of the horizon-fluid based on the theory of fluctuations à la Kubo. The main advantage of our approach is that our analysis remains for the most part independent of the details of the underlying microscopic theory and hence the conclusions reached here are model independent. We show that the coefficient of bulk viscosity for the horizon-fluid matches exactly with the value found from the equations of motion for the horizon-fluid.

  11. Observations of the Geometry of Horizon-Based Optical Navigation

    NASA Technical Reports Server (NTRS)

    Christian, John; Robinson, Shane

    2016-01-01

    NASA's Orion Project has sparked a renewed interest in horizon-based optical navigation(OPNAV) techniques for spacecraft in the Earth-Moon system. Some approaches have begun to explore the geometry of horizon-based OPNAV and exploit the fact that it is a conic section problem. Therefore, the present paper focuses more deeply on understanding and leveraging the various geometric interpretations of horizon-based OPNAV. These results provide valuable insight into the fundamental workings of OPNAV solution methods, their convergence properties, and associated estimate covariance. Most importantly, the geometry and transformations uncovered in this paper lead to a simple and non-iterative solution to the generic horizon-based OPNAV problem. This represents a significant theoretical advancement over existing methods. Thus, we find that a clear understanding of geometric relationships is central to the prudent design, use, and operation of horizon-based OPNAV techniques.

  12. Horizon of quantum black holes in various dimensions

    NASA Astrophysics Data System (ADS)

    Casadio, Roberto; Cavalcanti, Rogerio T.; Giugno, Andrea; Mureika, Jonas

    2016-09-01

    We adapt the horizon wave-function formalism to describe massive static spherically symmetric sources in a general (1 + D)-dimensional space-time, for D > 3 and including the D = 1 case. We find that the probability PBH that such objects are (quantum) black holes behaves similarly to the probability in the (3 + 1) framework for D > 3. In fact, for D ≥ 3, the probability increases towards unity as the mass grows above the relevant D-dimensional Planck scale mD. At fixed mass, however, PBH decreases with increasing D, so that a particle with mass m ≃mD has just about 10% probability to be a black hole in D = 5, and smaller for larger D. This result has a potentially strong impact on estimates of black hole production in colliders. In contrast, for D = 1, we find the probability is comparably larger for smaller masses, but PBH < 0.5, suggesting that such lower dimensional black holes are purely quantum and not classical objects. This result is consistent with recent observations that sub-Planckian black holes are governed by an effective two-dimensional gravitation theory. Lastly, we derive Generalised Uncertainty Principle relations for the black holes under consideration, and find a minimum length corresponding to a characteristic energy scale of the order of the fundamental gravitational mass mD in D > 3. For D = 1 we instead find the uncertainty due to the horizon fluctuations has the same form as the usual Heisenberg contribution, and therefore no fundamental scale exists.

  13. The Deepwater Horizon Disaster: What Happened and Why

    SciTech Connect

    Horne, Roland N.

    2011-01-05

    The Deepwater Horizon disaster was the largest oil spill in US history, and the second largest spill in the world. 11 men lost their lives in the explosion and fire. Although the impacts of the spill were evident to large numbers of people, its causes were harder to see. This lecture will focus on the technical aspects of the events that led to the spill itself: what happened on the rig before, during and after the event, up to the time the rig sank. As with many engineering disasters, the accident was due to a sequence of failures, including both technical systems and procedural issues. Although the causes were complex and interacting, the lecture will focus on four main problems: (1) the failure of the cement and casing seal, (2) the failure to recognize and respond to hydrocarbon flow into the riser, (3) the ignition of hydrocarbons on the rig, and (4) the failure of the blow-out preventer (BOP) to seal the well. The lecture will conclude with some suggestions as to how events such as the Deepwater Horizon disaster can be avoided in the future. (Roland N. Horne is the Thomas Davies Barrow Professor of Earth Sciences at Stanford University, and was the Chairman of Petroleum Engineering from 1995 to 2006. He holds BE, PhD and DSc degrees from the University of Auckland, New Zealand, all in Engineering Science. Horne is a member of the U.S. National Academy of Engineering and is also an Honorary Member of the Society of Petroleum Engineers.)

  14. Horizon sensor errors calculated by computer models compared with errors measured in orbit

    NASA Technical Reports Server (NTRS)

    Ward, K. A.; Hogan, R.; Andary, J.

    1982-01-01

    Using a computer program to model the earth's horizon and to duplicate the signal processing procedure employed by the ESA (Earth Sensor Assembly), errors due to radiance variation have been computed for a particular time of the year. Errors actually occurring in flight at the same time of year are inferred from integrated rate gyro data for a satellite of the TIROS series of NASA weather satellites (NOAA-A). The predicted performance is compared with actual flight history.

  15. Horizon Sensor Errors Calculated By Computer Models Compared With Errors Measured In Orbit

    NASA Astrophysics Data System (ADS)

    Ward, Kenneth A.; Hogan, Roger; Andary, James

    1982-06-01

    Using a computer program to model the earth's horizon and to duplicate the signal processing procedure employed by the ESA (Earth Sensor Assembly), errors due to radiance variation have been computed for a particular time of the year. Errors actually occurring in flight at the same time of year are inferred from integrated rate gyro data for a satellite of the TIROS series of NASA weather satellites (NOAA-7). The k)recLicted performance is compared with actual flight history.

  16. Earthquake Precursors An Example of Data Acquisition and Processing at Science Horizons

    NASA Astrophysics Data System (ADS)

    Cherry, J. T.

    2007-12-01

    Science Horizons has used COTS products, namely its AQUINAS® System and SeismicRadar®, to identify earthquake precursors from seismic data 1,000 miles from the earthquake's epicenter. We have assumed that a precursor has the same characteristics, specifically the same azimuth and horizontal phase velocity, as the earthquake's P-wave. In addition, we have also shown the superiority of seismic arrays to detect precursors. The precursors identified by SeismicRadar® preceded the earthquakes with times ranging from thirteen hours to one minute. Therefore, one can conclude that the same assumption and the same technology should be able to detect numerous precursors that are a few miles from a pending earthquake's epicenter. If this conclusion is shown to be valid in seismic areas, earthquake precursors will no longer be elusive. Then we will be able to create algorithms, based on the precursor's location, duration, and frequency, that reliably predict earthquakes. Science Horizons has a patent pending on this earthquake prediction method. For more information regarding Science Horizons' earthquake prediction method, please go to our website at http://www.horizon.com .

  17. Multiple microtektite horizons in upper Eocene marine sediments: No evidence for mass extinctions

    USGS Publications Warehouse

    Keller, G.; D'Hondt, S.; Vallier, T.L.

    1983-01-01

    Microtektites have been recovered from three horizons in eight middle Eocene to middle Oligocene marine sediment sequences. Five of these occurrences are coeval and of latest Eocene age (37.5 to 38.0 million years ago); three are coeval and of early late Eocene age (38.5 to 39.5 million years ago); and three are of middle Oligocene age (31 to 32 million years ago). In addition, rare probable microtektites have been found in sediments with ages of about 36.0 to 36.5 million years. The microtektite horizon at 37.5 to 38.0 million years can be correlated with the North American tektite-strewn field, which has a fission track age (minimum) of 34 to 35 million years and a paleomagnetic age of 37.5 to 38.0 million years. There is no evidence for mass faunal extinctions at any of the microtektite horizons. Many of the distinct faunal changes that occurred in the middle Eocene to middle Oligocene can be related to the formation of the Antarctic ice sheet and the associated cooling phenomena and intensification of bottom currents that led to large-scale dissolution of calcium carbonate and erosion, which created areally extensive hiatuses in the deep-sea sediment records. The occurrence of microtektite horizons of several ages and the lack of evidence for faunal extinctions suggest that the effects of extraterrestrial bolide impacts may be unimportant in the biologic realm during middle Eocene to middle Oligocene time.

  18. New Horizons mission to Pluto and the Kuiper belt

    NASA Astrophysics Data System (ADS)

    McKinnon, W.; Stern, S.; Weaver, H.; Young, L.; Olkin, C.; New Horizons Science Team

    2014-07-01

    two 30--50 kilometer-diameter Kuiper Belt Objects (KBOs) if 1) the spacecraft is in good health, 2) at least one accessible KBO can be located from the Earth or Earth orbit in time, and 3) NASA approves an extended mission. New Horizons previously conducted a successful encounter with Jupiter and the Galilean satellites, has collected and is collecting valuable cruise science data, and became the prototype for NASA's medium-scale, PI-led New Frontiers planetary mission class. The NH flyby of the Pluto system will represent a watershed in the scientific exploration of the Solar System, by exploring a new class of planet in the Solar System --- dwarf planets --- and an accompanying, extensive satellite system. In this review talk we provide a more in-depth overview of the spacecraft, payload, and flyby plans.

  19. 76 FR 55427 - Horizon Technology Finance Corporation, et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-07

    ... COMMISSION Horizon Technology Finance Corporation, et al.; Notice of Application August 31, 2011. AGENCY...(a) of the Act. Applicants: Horizon Technology Finance Corporation (the ``Company''), Horizon Technology Finance Management LLC (the ``Investment Adviser''), Longview SBIC GP LLC (the ``General...

  20. Factors Associated with Caregiver Burden in Dementia: 1-Year Follow-Up Study

    PubMed Central

    Shim, Sang Hong; Kang, Hyo Shin; Kim, Ji Hae

    2016-01-01

    Objective Dementia symptoms (cognitive function, daily-living function, and neuropsychiatric symptoms) become more serious over time, which is likely to increase caregiver burden. The aim of this study is to investigate which dementia-related symptoms, and how the progression of these symptoms, have influenced caregiver burden during a 1-year follow-up assessment. Methods A total of 110 patients with dementia were assessed for their cognitive function, daily-living function, and neuropsychiatric symptoms. Caregivers were assessed for their caregiver burden. Bivariate analyses were conducted between caregiver burden and dementia patients' symptoms, in order to examine which particular symptoms were significantly associated with caregiver burden at the baseline. A multiple regression analysis was then conducted with each significantly associated variable with a view to identifying determinants, influencing caregiver burden. Additionally, bivariate analyses were conducted between the changes in caregiver burden and the changes in patients' symptoms, to investigate which patient variable could best describe caregiver burden from baseline to the 1-year follow-up. A multiple regression analysis was conducted with each significantly-associated change in symptom, in order to identify determinants that influence a change in caregiver burden. Results Neuropsychiatric symptoms, such as irritability, aberrant motor-behavior, delusions and disinhibition were found to be significant predictors of caregiver burden at baseline, according to multiple regression analysis. In addition, changes in neuropsychiatric symptoms, such as delusions, agitation and memory-related functioning in daily-living significantly predict a change in caregiver burden. Conclusion Our results demonstrate that neuropsychiatric symptoms and memory impairment in daily-living functions are significant predictors of an increase in caregiver burden. PMID:26766945

  1. Horizon shells and BMS-like soldering transformations

    NASA Astrophysics Data System (ADS)

    Blau, Matthias; O'Loughlin, Martin

    2016-03-01

    We revisit the theory of null shells in general relativity, with a particular emphasis on null shells placed at horizons of black holes. We study in detail the considerable freedom that is available in the case that one solders two metrics together across null hypersurfaces (such as Killing horizons) for which the induced metric is invariant under translations along the null generators. In this case the group of soldering transformations turns out to be infinite dimensional, and these solderings create non-trivial horizon shells containing both massless matter and impulsive gravitational wave components. We also rephrase this result in the language of Carrollian symmetry groups. To illustrate this phenomenon we discuss in detail the example of shells on the horizon of the Schwarzschild black hole (with equal interior and exterior mass), uncovering a rich classical structure at the horizon and deriving an explicit expression for the general horizon shell energy-momentum tensor. In the special case of BMS-like soldering supertranslations we find a conserved shell-energy that is strikingly similar to the standard expression for asymptotic BMS supertranslation charges, suggesting a direct relation between the physical properties of these horizon shells and the recently proposed BMS supertranslation hair of a black hole.

  2. Physical process first law for bifurcate Killing horizons

    SciTech Connect

    Amsel, Aaron J.; Marolf, Donald; Virmani, Amitabh

    2008-01-15

    The physical process version of the first law for black holes states that the passage of energy and angular momentum through the horizon results in a change in area ({kappa}/8{pi}){delta}A={delta}E-{omega}{delta}J, so long as this passage is quasistationary. A similar physical process first law can be derived for any bifurcate Killing horizon in any spacetime dimension d{>=}3 using much the same argument. However, to make this law nontrivial, one must show that sufficiently quasistationary processes do in fact occur. In particular, one must show that processes exist for which the shear and expansion remain small, and in which no new generators are added to the horizon. Thorne, MacDonald, and Price considered related issues when an object falls across a d=4 black hole horizon. By generalizing their argument to arbitrary d{>=}3 and to any bifurcate Killing horizon, we derive a condition under which these effects are controlled and the first law applies. In particular, by providing a nontrivial first law for Rindler horizons, our work completes the parallel between the mechanics of such horizons and those of black holes for d{>=}3. We also comment on the situation for d=2.

  3. Lunar horizon glow and the Clementine mission

    NASA Technical Reports Server (NTRS)

    Zook, H. A.; Potter, A. E.

    1994-01-01

    The Clementine spacecraft is to be launched into Earth orbit in late January for subsequent insertion into lunar orbit in late February, 1994. There, its primary mission is to produce -- over a period of about two months -- a new photographic map of the entire surface of the Moon; this will be done, in a variety of wavelengths and spatial resolutions, in a manner greatly superior to that previously accomplished for the whole Moon. It will then go on to fly by and photograph the asteroid Geographos. A secondary goal that has been accepted for this mission is to take a series of photographs designed to capture images of, and determine the brightness and extent of, the Lunar Horizon Glow (LHG). One form of LHG is caused by the solar stimulation of emission from Na and K atoms in the lunar exosphere. The scale height of this exosphere is of the order of 100 km. There are also brighter LHG components, with much smaller scale heights, that appear to be caused by scattered off of an exospheric lunar dust cloud.

  4. Perturbative string thermodynamics near black hole horizons

    NASA Astrophysics Data System (ADS)

    Mertens, Thomas G.; Verschelde, Henri; Zakharov, Valentin I.

    2015-06-01

    We provide further computations and ideas to the problem of near-Hagedorn string thermodynamics near (uncharged) black hole horizons, building upon our earlier work [1]. The relevance of long strings to one-loop black hole thermodynamics is emphasized. We then provide an argument in favor of the absence of α'-corrections for the (quadratic) heterotic thermal scalar action in Rindler space. We also compute the large k limit of the cigar orbifold partition functions (for both bosonic and type II superstrings) which allows a better comparison between the flat cones and the cigar cones. A discussion is made on the general McClain-Roth-O'Brien-Tan theorem and on the fact that different torus embeddings lead to different aspects of string thermodynamics. The black hole/string correspondence principle for the 2d black hole is discussed in terms of the thermal scalar. Finally, we present an argument to deal with arbitrary higher genus partition functions, suggesting the breakdown of string perturbation theory (in g s ) to compute thermodynam-ical quantities in black hole spacetimes.

  5. Large Dust Devil on Horizon, Sol 468

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This movie clip shows a large, distant dust devil -- a whirlwind that lofts dust into the air -- as a dark shape on the horizon near the right side of the images. This dust devil was about 5 kilometers (3 miles) away from NASA's Mars Exploration Rover Spirit, and may have been up to 200 meters or yards in diameter. Smaller dust devils closer to the rover appear bright against the dark ground. Spirit's navigation camera took these images on the rover's 468th martian day, or sol (April 27, 2005.) Contrast has been enhanced for anything in the images that changes from frame to frame, that is, for the dust devil. The number of seconds elapsed since the first frame is indicated at lower left of the images, typically 20 seconds between frames.

    Scientists expected dust devils since before Spirit landed. The landing area inside Gusev Crater is filled with dark streaks left behind when dust devils pick dust up from an area. It is also filled with bright 'hollows,' which are dust-filled miniature craters. Dust covers most of the terrain. Winds flow into and out of Gusev crater every day. The Sun heats the surface so that the surface is warm to the touch even though the atmosphere at 2 meters (6 feet) above the surface would be chilly. That temperature contrast causes convection. Mixing the dust, winds, and convection can trigger dust devils.

  6. LANDSAT-4 horizon scanner performance evaluation

    NASA Technical Reports Server (NTRS)

    Bilanow, S.; Chen, L. C.; Davis, W. M.; Stanley, J. P.

    1984-01-01

    Representative data spans covering a little more than a year since the LANDSAT-4 launch were analyzed to evaluate the flight performance of the satellite's horizon scanner. High frequency noise was filtered out by 128-point averaging. The effects of Earth oblateness and spacecraft altitude variations are modeled, and residual systematic errors are analyzed. A model for the predicted radiance effects is compared with the flight data and deficiencies in the radiance effects modeling are noted. Correction coefficients are provided for a finite Fourier series representation of the systematic errors in the data. Analysis of the seasonal dependence of the coefficients indicates the effects of some early mission problems with the reference attitudes which were computed by the onboard computer using star trackers and gyro data. The effects of sun and moon interference, unexplained anomalies in the data, and sensor noise characteristics and their power spectrum are described. The variability of full orbit data averages is shown. Plots of the sensor data for all the available data spans are included.

  7. Observational Study of 1-Year Mortality Rates Before and After a Major Earthquake Among Chinese Nonagenarians

    PubMed Central

    Dong, Birong; Wu, Hongmei; Zhang, Yanling; Guralnik, Jack M.; Malmstrom, Theodore K.; Morley, John E.

    2011-01-01

    Background. Little is known about mortality among nonagenarians after an earthquake. Methods. Using secondary data analyses from the 2005 study called the Project of Longevity and Aging in Dujiangyan(n = 870), 1-year mortality rates were compared among a pre-earthquake group and a post-earthquake group of nonagenarians. All participants were from Dujiangyan, 50 km from the epicenter of the May 12, 2008 earthquake, in China. The pre-earthquake group was a subset of the 870 Project of Longevity and Aging in Dujiangyan participants, ages 93–95 years at the beginning of “Time Frame 1” (July 2005 through June 2006; n = 228). The post-earthquake group was a different subset of the 870 Project of Longevity and Aging in Dujiangyan participants, ages 93–95 years and alive at the beginning of Time Frame 2 (July 2008 through June 2009; n = 235). Time Frame 2 excluded a 7-week period following the earthquake in order to account for deaths due to trauma. Pre-earthquake health assessment data from the 2005 Project of Longevity and Aging in Dujiangyan study were used to calculate unadjusted/adjusted hazard ratios (HRs) for mortality. Results. One-year mortality rates were 8.3% (19/228) and 16.2% (38/235) in the pre-earthquake group and the post-earthquake group, respectively (p =.01). In unadjusted analyses, only “being in the post-earthquake group” was associated with death (HR = 2.04; 95% confidence interval [CI], 1.17–3.53; p = .011). In the multivariable Cox regression model, being in the post-earthquake group continued to be the strongest risk factor associated with mortality (HR = 2.47; 95% CI, 1.39–4.40; p = .002). Other significant risk factors included impaired cognition (HR = 1.97; 95% CI, 1.10–3.53; p = .024), serum albumin (HR = 0.90; 95% CI, 0.82–0.98; p < .015), and serum triglycerides (HR = 1.51; 95% CI, 1.15–1.99; p = .003). Conclusion. The May 12, 2008 earthquake in Wenchuan, China, was associated with a twofold increase in the 1-year

  8. Horizon scan of global conservation issues for 2011.

    PubMed

    Sutherland, William J; Bardsley, Sarah; Bennun, Leon; Clout, Mick; Côté, Isabelle M; Depledge, Michael H; Dicks, Lynn V; Dobson, Andrew P; Fellman, Liz; Fleishman, Erica; Gibbons, David W; Impey, Andrew J; Lawton, John H; Lickorish, Fiona; Lindenmayer, David B; Lovejoy, Thomas E; Nally, Ralph Mac; Madgwick, Jane; Peck, Lloyd S; Pretty, Jules; Prior, Stephanie V; Redford, Kent H; Scharlemann, Jörn P W; Spalding, Mark; Watkinson, Andrew R

    2011-01-01

    This review describes outcomes of a 2010 horizon-scanning exercise building upon the first exercise conducted in 2009. The aim of both horizon scans was to identify emerging issues that could have substantial impacts on the conservation of biological diversity, and to do so sufficiently early to encourage policy-relevant, practical research on those issues. Our group included professional horizon scanners and researchers affiliated with universities and non- and inter-governmental organizations, including specialists on topics such as invasive species, wildlife diseases and coral reefs. We identified 15 nascent issues, including new greenhouse gases, genetic techniques to eradicate mosquitoes, milk consumption in Asia and societal pessimism. PMID:21126797

  9. Depression and posttraumatic stress disorder in temporary settlement residents 1 year after the Sichuan earthquake.

    PubMed

    Cheng, Zhang; Ma, Ning; Yang, Lei; Agho, Kingsley; Stevens, Garry; Raphael, Beverley; Cui, Lijun; Liu, Yongqiao; Yan, Baoping; Ma, Hong; Yu, Xin

    2015-03-01

    The authors sought to determine the prevalence and risk factors for major depressive disorder and posttraumatic stress disorder (PTSD) among survivors living in temporary accommodation in the Yongxing settlement in Mianyang city 1 year after the Sichuan earthquake for further interventions. They interviewed 182 residents, using the Structured Clinical Interview for DSM-IV Axis I Disorders and a self-report questionnaire. The 12-month prevalence of depressive disorder and PTSD were 48.9% and 39.6%, respectively. Multivariate analysis indicated that bereaved survivors were 5.51 times (adjusted odds ratio [AOR] = 5.51; 95% confidence interval [CI] =2.14-14.22) more likely to report PTSD and 2.42 times (AOR = 2.42; 95%CI =1.00-5.48) more likely to report depressive disorder than nonbereaved survivors. Older age and receipt of government financial support were significantly associated with 12-month PTSD. Depressive disorder 12 months after the earthquake was associated with receipt of government financial support, pre-earthquake physical illness, single marital status, being currently employed, and Han ethnicity. PMID:23666829

  10. Micromorphometric features of pore space in the plow horizons of loamy soils

    NASA Astrophysics Data System (ADS)

    Skvortsova, E. B.; Sanzharova, S. I.

    2007-04-01

    A computer-based analysis of thin sections has been applied to study pore space in the plow horizons of loamy soils in European Russia and Ukraine. Differences in the morphology of soil macro-and mesopores are shown. It is argued that agrogenic impacts result in the convergence of the shape and orientation of macropores in plowed loamy soils of the forest, forest-steppe, and steppe zones. At the same time, this convergence is not observed for the soil mesopores.

  11. "Far Horizons" -- Near-space Exploration At The Adler Planetarium

    NASA Astrophysics Data System (ADS)

    Hammergren, Mark; Gyuk, G.; Friedman, R. B.

    2011-01-01

    Over the past four years, the Adler Planetarium has developed a diverse suite of educational activities involving hands-on scientific exploration via our "Far Horizons" high-altitude ballooning program. These efforts largely have been focused on increasing excitement and motivation for learning outside of school time, and include middle school summer camps, a high school summer program (the Astro-Science Workshop), school-year internships for high school students, summer internships for undergraduates, a NSF-funded graduate fellowship, and an active public volunteer program. In 2010, our programs were dedicated to the memory of renowned Chicago adventurer and explorer Steve Fossett. In 2011, in continued tribute to Steve Fossett, we further expand our out-of-school time programs with a summer workshop designed to enable high school teachers to form and advise student high-altitude ballooning clubs. This model program will be developed as one element of our ongoing partnership with the Air Force Academy High School in Chicago. This material is based in part upon work supported by the National Science Foundation under Grant No. 0525995.

  12. Testing General Relativity with the Event Horizon Telescope

    NASA Astrophysics Data System (ADS)

    Benkevitch, Leonid; Fish, V. L.; Johannsen, T.; Akiyama, K.; Broderick, A. E.; Psaltis, D.; Doeleman, S.; Monnier, J. D.; Baron, F.

    2013-01-01

    Strong gravitational lensing of light near black holes is one of the effects predicted by general relativity (GR). Emission close to a black hole will typically be lensed to illuminate the last photon orbit, creating a feature known as the black hole 'shadow' or 'silhouette'. The precise size and shape of the shadow is dependent on black hole mass, spin, and the space-time metric. The Event Horizon Telescope (EHT) is a (sub)mm VLBI network that can achieve Schwarzschild Radius scale resolution on SgrA*, the 4 million solar mass black hole at the Galactic Center. Here we present initial studies of how recent and future EHT observations of SgrA* can be used to test the No-Hair theorem by searching for deviations from the expected shadow morphology. We have developed a pipeline for producing synthetic EHT data sets from black hole emission models using perturbed space-time metrics that violate the No-Hair theorem. Employing imaging and modelfitting algorithms tailored for EHT data, we extract parameters of the black hole shadow. Preliminary results indicate that the EHT can provide a new way to test GR in the strong gravity regime that is complementary to techniques in other fields.

  13. Complementary and Alternative Medicine (CAM): Expanding Horizons of Health Care

    MedlinePlus

    ... Past Issues Special Section CAM Expanding Horizons of Health Care Past Issues / Winter 2009 Table of Contents For ... and why it is important to tell your health care providers about your use of CAM. We hope ...

  14. Entanglement entropy of a black hole and isolated horizon

    NASA Astrophysics Data System (ADS)

    Shi, Jianhua; Hu, Shuangqi; Zhao, Ren

    2013-02-01

    Using Unruh-Verlinde temperature obtained by entropic force, we directly calculate partition functions of quantum field in Schwarzschild spacetime via quantum statistical method and derive the expression of the black hole statistical entropy. In our calculation the lower limit of integral is the location of isolated horizon introduced in loop quantum gravity and the upper limit of integral is infinity. So the obtained entropy is the statistical entropy from isolated horizon to the infinite. In our calculation there are not the cutoff and approximation. The results showed that, as long as proper Immirzi parameters are selected, the entropy obtained by loop quantum gravity is consistent with the quantum statistical entropy outside the black hole horizon. Therefore the black hole entropy is a quantum entanglement entropy outside the isolated horizon.

  15. Note on electrical and thermodynamic properties of isolated horizons

    NASA Astrophysics Data System (ADS)

    Chen, Gerui; Wu, Xiaoning; Gao, Sijie

    2015-03-01

    The electrical laws and Carnot cycle of isolated horizons (IH) are investigated in this paper. We establish Ohm's law and Joule's law of isolated horizons and find that the conceptual picture of black holes (membrane paradigm) can also apply to this kind of quasilocal black holes. We also investigate the geometrical properties near nonrotating IHs and find that under the first-order approximation of r , there exist a Killing vector ∂∂u/ and a Hamiltonian conjugate to it, so this vector can be thought to be a physical observer. We calculate the energy as measured at infinity of a particle at rest outside a nonrotating IH, and we use this result to construct a reversible Carnot cycle with the isolated horizon as a cold reservoir, which confirms the thermodynamic nature of isolated horizons.

  16. JERSEY APPROACH VIADUCT LOOKING EAST, NOTE VERRAZANO TOWERS ON HORIZON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    JERSEY APPROACH VIADUCT LOOKING EAST, NOTE VERRAZANO TOWERS ON HORIZON TO LEFT - Goethals Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

  17. Universal properties of the near-horizon optical geometry

    NASA Astrophysics Data System (ADS)

    Gibbons, G. W.; Warnick, C. M.

    2009-03-01

    Making use of the fact that the optical geometry near a static nondegenerate Killing horizon is asymptotically hyperbolic, we investigate some universal features of black-hole horizons. Applying the Gauss-Bonnet theorem allows us to establish some general properties of gravitational lensing, valid for all black holes. Hyperbolic geometry allows us to find rates for the loss of scalar, vector, and fermionic “hair” as objects fall quasistatically towards the horizon, extending previous results for Schwarzschild to all static Killing horizons. In the process we find the Liénard-Wiechert potential for hyperbolic space and calculate the force between electrons mediated by neutrinos, extending the flat space result of Feinberg and Sucher. We further demonstrate how these techniques allow us to derive the exact Copson-Linet potential due to a point charge in a Schwarzschild background in a simple fashion.

  18. The Cauchy horizon singularity inside Kerr black holes

    NASA Astrophysics Data System (ADS)

    Burko, Lior M.; Khanna, Gaurav

    2016-03-01

    The numerical technology that allows for the careful evolution of linearized fields inside Kerr black holes and the study of their behavior approaching the Cauchy horizon singularity includes a number of interesting aspects. The latter include compactified hyperboloidal coordinates and foliation, mixed type hyperbolic-elliptic PDE, and initial data evolution where all equal-coordinate hypersurfaces are spacelike. We review the need for the numerical technology that allows for the solution of the spin-2 Teukolsky equation inside Kerr black holes, and discuss the main features thereof. We present new results about the numerical properties of the Cauchy horizon singularity and their correspondence with the predictions of perturbative analysis. We then discuss present directions of study, which include the sub-dominant azimuthal modes, approaching the Cauchy horizon singularity along timelike directions, approaching the Marolf-Ori (``outflying'') singularity and the studying the fields along the Cauchy horizon.

  19. Universal properties of the near-horizon optical geometry

    SciTech Connect

    Gibbons, G. W.; Warnick, C. M.

    2009-03-15

    Making use of the fact that the optical geometry near a static nondegenerate Killing horizon is asymptotically hyperbolic, we investigate some universal features of black-hole horizons. Applying the Gauss-Bonnet theorem allows us to establish some general properties of gravitational lensing, valid for all black holes. Hyperbolic geometry allows us to find rates for the loss of scalar, vector, and fermionic ''hair'' as objects fall quasistatically towards the horizon, extending previous results for Schwarzschild to all static Killing horizons. In the process we find the Lienard-Wiechert potential for hyperbolic space and calculate the force between electrons mediated by neutrinos, extending the flat space result of Feinberg and Sucher. We further demonstrate how these techniques allow us to derive the exact Copson-Linet potential due to a point charge in a Schwarzschild background in a simple fashion.

  20. Cutoffs, stretched horizons, and black hole radiators

    NASA Astrophysics Data System (ADS)

    Kaloper, Nemanja

    2012-11-01

    We argue that if the UV cutoff of an effective field theory with many low energy degrees of freedom is of the order, or below, the scale of the stretched horizon in a black hole background, which in turn is significantly lower than the Planck scale, the black hole radiance rate may not be enhanced by the emission of all the light IR modes. Instead, there may be additional suppressions hidden in the UV completion of the field theory, which really control which light modes can be emitted by the black hole. It could turn out that many degrees of freedom cannot be efficiently emitted by the black hole, and so the radiance rate may be much smaller than its estimate based on the counting of the light IR degrees of freedom. If we apply this argument to the Randall-Sundrum II (RS2) brane world, it implies that the emission rates of the low energy conformal field theory modes will be dramatically suppressed: its UV completion is given by the bulk gravity on AdS5×S5, and the only bulk modes which could be emitted by a black hole are the 4-dimensional (4D) s waves of bulk modes with small 5-dimensional momentum, or equivalently, small 4D masses. Further, their emission is suppressed by bulk warping, which lowers the radiation rate much below the IR estimate, yielding a radiation flux ˜(TBHL)2LHawking˜(TBH/MPl)2NLHawking, where LHawking is the Hawking radiation rate of a single light species. This follows directly from low conformal field theory cutoff μ˜L-1≪MPl, a large number of modes N≫1 and the fact that 4D gravity in RS2 is induced, MPl2≃Nμ2.

  1. Output-feedback control of combined sewer networks through receding horizon control with moving horizon estimation

    NASA Astrophysics Data System (ADS)

    Joseph-Duran, Bernat; Ocampo-Martinez, Carlos; Cembrano, Gabriela

    2015-10-01

    An output-feedback control strategy for pollution mitigation in combined sewer networks is presented. The proposed strategy provides means to apply model-based predictive control to large-scale sewer networks, in-spite of the lack of measurements at most of the network sewers. In previous works, the authors presented a hybrid linear control-oriented model for sewer networks together with the formulation of Optimal Control Problems (OCP) and State Estimation Problems (SEP). By iteratively solving these problems, preliminary Receding Horizon Control with Moving Horizon Estimation (RHC/MHE) results, based on flow measurements, were also obtained. In this work, the RHC/MHE algorithm has been extended to take into account both flow and water level measurements and the resulting control loop has been extensively simulated to assess the system performance according different measurement availability scenarios and rain events. All simulations have been carried out using a detailed physically based model of a real case-study network as virtual reality.

  2. A horizon scan of global conservation issues for 2015.

    PubMed

    Sutherland, William J; Clout, Mick; Depledge, Michael; Dicks, Lynn V; Dinsdale, Jason; Entwistle, Abigail C; Fleishman, Erica; Gibbons, David W; Keim, Brandon; Lickorish, Fiona A; Monk, Kathryn A; Ockendon, Nancy; Peck, Lloyd S; Pretty, Jules; Rockström, Johan; Spalding, Mark D; Tonneijck, Femke H; Wintle, Bonnie C

    2015-01-01

    This paper presents the results of our sixth annual horizon scan, which aims to identify phenomena that may have substantial effects on the global environment, but are not widely known or well understood. A group of professional horizon scanners, researchers, practitioners, and a journalist identified 15 topics via an iterative, Delphi-like process. The topics include a novel class of insecticide compounds, legalisation of recreational drugs, and the emergence of a new ecosystem associated with ice retreat in the Antarctic. PMID:25433442

  3. Supertranslations and Superrotations at the Black Hole Horizon

    NASA Astrophysics Data System (ADS)

    Donnay, Laura; Giribet, Gaston; González, Hernán A.; Pino, Miguel

    2016-03-01

    We show that the asymptotic symmetries close to nonextremal black hole horizons are generated by an extension of supertranslations. This group is generated by a semidirect sum of Virasoro and Abelian currents. The charges associated with the asymptotic Killing symmetries satisfy the same algebra. When considering the special case of a stationary black hole, the zero mode charges correspond to the angular momentum and the entropy at the horizon.

  4. A horizon scan of global conservation issues for 2013.

    PubMed

    Sutherland, William J; Bardsley, Sarah; Clout, Mick; Depledge, Michael H; Dicks, Lynn V; Fellman, Liz; Fleishman, Erica; Gibbons, David W; Keim, Brandon; Lickorish, Fiona; Margerison, Ceri; Monk, Kathryn A; Norris, Kenneth; Peck, Lloyd S; Prior, Stephanie V; Scharlemann, Jörn P W; Spalding, Mark D; Watkinson, Andrew R

    2013-01-01

    This paper presents the findings of our fourth annual horizon-scanning exercise, which aims to identify topics that increasingly may affect conservation of biological diversity. The 15 issues were identified via an iterative, transferable process by a team of professional horizon scanners, researchers, practitioners, and a journalist. The 15 topics include the commercial use of antimicrobial peptides, thorium-fuelled nuclear power, and undersea oil production. PMID:23219597

  5. Supertranslations and Superrotations at the Black Hole Horizon.

    PubMed

    Donnay, Laura; Giribet, Gaston; González, Hernán A; Pino, Miguel

    2016-03-01

    We show that the asymptotic symmetries close to nonextremal black hole horizons are generated by an extension of supertranslations. This group is generated by a semidirect sum of Virasoro and Abelian currents. The charges associated with the asymptotic Killing symmetries satisfy the same algebra. When considering the special case of a stationary black hole, the zero mode charges correspond to the angular momentum and the entropy at the horizon. PMID:26991167

  6. Optical Navigation Preparations for New Horizons Pluto Flyby

    NASA Technical Reports Server (NTRS)

    Owen, William M., Jr.; Dumont, Philip J.; Jackman, Coralie D.

    2012-01-01

    The New Horizons spacecraft will encounter Pluto and its satellites in July 2015. As was the case for the Voyager encounters with Jupiter, Saturn, Uranus and Neptune, mission success will depend heavily on accurate spacecraft navigation, and accurate navigation will be impossible without the use of pictures of the Pluto system taken by the onboard cameras. We describe the preparations made by the New Horizons optical navigators: picture planning, image processing algorithms, software development and testing, and results from in-flight imaging.

  7. Thermodynamics of cosmological horizons in f(T) gravity

    SciTech Connect

    Bamba, Kazuharu; Geng, Chao-Qiang E-mail: geng@phys.nthu.edu.tw

    2011-11-01

    We explore thermodynamics of the apparent horizon in f(T) gravity with both equilibrium and non-equilibrium descriptions. We find the same dual equilibrium/non-equilibrium formulation for f(T) as for f(R) gravity. In particular, we show that the second law of thermodynamics can be satisfied for the universe with the same temperature outside and inside the apparent horizon.

  8. Runge-Kutta Discretizations of Infinite Horizon Optimal Control Problems with Steady-State Invariance

    NASA Astrophysics Data System (ADS)

    Diele, F.; Marangi, C.; Ragni, S.

    2009-08-01

    Direct numerical approximation of a continuous-time infinite horizon control problem, requires to recast the model as a discrete-time, finite-horizon control model. The quality of the optimization results can be heavily degraded if the discretization process does not take into account features of the original model to be preserved. Restricting their attention to optimal growh problems with a steady state, Mercenier and Michel in [1] and [2], studied the conditions to be imposed for ensuring that discrete first-order approximation models have the same steady states as the infinite-horizon continuous-times counterpart. Here we show that Mercenier and Michel scheme is a first order partitioned Runge-Kutta method applied to the state-costate differential system which arises from the Pontryagin maximum principle. The main consequence is that it is possible to consider high order schemes which generalize that algorithm by preserving the steady-growth invariance of the solutions with respect to the discretization process. Numerical examples show the efficiency and accuracy of the proposed methods when applied to the classical Ramsey growth model.

  9. Comparisons Between New Horizons Results and Long-Term Monitoring of Pluto

    NASA Astrophysics Data System (ADS)

    Buie, M. W.; Stern, A.; Young, L. A.; Weaver, H. A., Jr.; Olkin, C.; Ennico Smith, K.; Moore, J. M.; Grundy, W. M.

    2015-12-01

    The New Horizons encounter data have revealed a diverse and complicated surface and atmosphere for Pluto showing strong correlations between geologic features and the albedo and compositional units known from ground- and HST-based observations over the decades prior. This presentation will delve into detailed comparisons between the long time base and low spatial resolution data and the new high resolution snapshot of Pluto from the flyby. Special emphasis will be placed on the albedo and near-infrared spectral evolution over time. We will compare the albedo maps from the late 1980's built on mutual event data and two epochs of HST observations against the New Horizons images, after correcting for viewing geometry. Also included will be a discussion of the evolutionary trends in the hemispherically averaged spectral properties from Lowell Observatory and IRTF data against the resolved compositional and spectral maps from New Horizons. The combination of these data sets now permits an unprecedented ability to constrain time-variability on the surface from apparent changes due to viewing geometry and surface inhomogeneities. These comparisons require a reconcilliation of surface scattering properties that are enabled by the firm determination of the size of Pluto.

  10. Comparisons Between New Horizons Results and Long-Term Monitoring of Pluto

    NASA Astrophysics Data System (ADS)

    Buie, M. W.; Stern, A.; Young, L. A.; Weaver, H. A., Jr.; Olkin, C.; Ennico Smith, K.; Moore, J. M.; Grundy, W. M.

    2014-12-01

    The New Horizons encounter data have revealed a diverse and complicated surface and atmosphere for Pluto showing strong correlations between geologic features and the albedo and compositional units known from ground- and HST-based observations over the decades prior. This presentation will delve into detailed comparisons between the long time base and low spatial resolution data and the new high resolution snapshot of Pluto from the flyby. Special emphasis will be placed on the albedo and near-infrared spectral evolution over time. We will compare the albedo maps from the late 1980's built on mutual event data and two epochs of HST observations against the New Horizons images, after correcting for viewing geometry. Also included will be a discussion of the evolutionary trends in the hemispherically averaged spectral properties from Lowell Observatory and IRTF data against the resolved compositional and spectral maps from New Horizons. The combination of these data sets now permits an unprecedented ability to constrain time-variability on the surface from apparent changes due to viewing geometry and surface inhomogeneities. These comparisons require a reconcilliation of surface scattering properties that are enabled by the firm determination of the size of Pluto.

  11. Deformation of codimension-2 surfaces and horizon thermodynamics

    NASA Astrophysics Data System (ADS)

    Cao, Li-Ming

    2011-03-01

    The deformation equation of a spacelike submanifold with an arbitrary codimension is given by a general construction without using local frames. In the case of codimension-1, this equation reduces to the evolution equation of the extrinsic curvature of a spacelike hypersurface. In the more interesting case of codimension-2, after selecting a local null frame, this deformation equation reduces to the well known (cross) focusing equations. We show how the thermodynamics of trapping horizons is related to these deformation equations in two different formalisms: with and without introducing quasilocal energy. In the formalism with the quasilocal energy, the Hawking mass in four dimension is generalized to higher dimension, and it is found that the deformation of this energy inside a marginal surface can be also decomposed into the contributions from matter fields and gravitational radiation as in the four dimension. In the formalism without the quasilocal energy, we generalize the definition of slowly evolving future outer trapping horizons proposed by Booth to past trapping horizons. The dynamics of the trapping horizons in FLRW universe is given as an example. Especially, the slowly evolving past trapping horizon in the FLRW universe has close relation to the scenario of slow-roll inflation. Up to the second order of the slowly evolving parameter in this generalization, the temperature (surface gravity) associated with the slowly evolving trapping horizon in the FLRW universe is essentially the same as the one defined by using the quasilocal energy.

  12. Residential property values predict prevalent obesity but do not predict 1 year weight change

    PubMed Central

    Drewnowski, Adam; Aggarwal, Anju; Tang, Wesley; Moudon, Anne Vernez

    2014-01-01

    Objective Lower socioeconomic status (SES) has been linked with higher obesity rates but not with weight gain. This study examined whether SES can predict short-term weight change. Design and Methods The Seattle Obesity Study II was based on an observational cohort of 440 adults. Weights and heights were measured at baseline and at 1 y. Self-reported education and incomes were obtained by questionnaire. Home addresses were linked to tax parcel property values from the King Co. tax assessor. Associations among SES variables, prevalent obesity, and 1 y weight change were examined using multivariable linear regressions. Results Low residential property values at tax parcel predicted prevalent obesity at baseline and at 1 y. Living in the top quartile of house prices reduced obesity risk by 80% at both time points. At 1 year, about 38% of the sample lost >1kg body weight; 32% maintained (± 1kg), and 30% gained >1kg. In adjusted models, none of the baseline SES measures had any impact on 1 y weight change. Conclusions SES variables, including tax parcel property values predicted prevalent obesity but did not predict short-term weight change. These findings, based on longitudinal cohort data, suggest other mechanisms are involved in short-term weight change. PMID:25684713

  13. Latent Transition Models to Study Women's Changing of Dietary Patterns From Pregnancy to 1 Year Postpartum

    PubMed Central

    Sotres-Alvarez, Daniela; Herring, Amy H.; Siega-Riz, Anna-Maria

    2013-01-01

    Latent class models are useful for classifying subjects by dietary patterns. Our goals were to use latent transition models to identify dietary patterns during pregnancy and postpartum, to estimate the prevalence of these dietary patterns, and to model transition probabilities between dietary patterns as a function of covariates. Women who were enrolled in the Pregnancy, Infection, and Nutrition Study (University of North Carolina, 2000–2005) were followed for 1 year postpartum, and their diets were assessed in the second trimester and at 3 and 12 months postpartum (n = 519, 484, and 374, respectively) by using a food frequency questionnaire. After adjusting for energy intake, parity, smoking status, race, and education, we identified 3 dietary patterns and named them “prudent,” “health conscious Western,” and “Western.” Nulliparas were 2.9 and 2.1 times more likely to be in the “prudent” class than the “health conscious Western” or the “Western” class, respectively. The 3 dietary patterns were very stable, with the “health conscious Western” class being the least stable; the probability for staying in the same class was 0.74 and 0.87 at 3 and 12 months postpartum, respectively. Breastfeeding mothers were more likely than nonbreastfeeding mothers to switch dietary pattern class (P = 0.0286). Except for breastfeeding mothers, most women did not switch dietary patterns from pregnancy to postpartum. PMID:23538942

  14. Integrating horizon scanning and strategic risk prioritisation using a weight of evidence framework to inform policy decisions.

    PubMed

    Garnett, K; Lickorish, F A; Rocks, S A; Prpich, G; Rathe, A A; Pollard, S J T

    2016-08-01

    Poor connection between data on emerging issues and credible policy decisions continues to challenge governments, and is only likely to grow as demands on time and resources increase. Here we summarise recent efforts to integrate horizon scanning and risk prioritisation approaches to better connect emerging issues to the political discourse on environmental and food-related issues. Our categorisation of insights including potential future risks and opportunities to inform policy discussions has emerged from a structured three-year programme of horizon scanning for a UK pan-governmental futures partnership led by the Department for Environment, Food and Rural Affairs (Defra). Our efforts to integrate horizon scanning and risk prioritisation, utilising a qualitative weight of evidence framework, has created a systematic process for identifying all signals of potential future change with significant impact for the strategic mission and underlying values of policy actors. Our approach encourages an exploration of factors out of the control of organisations, recognising that resilience depends on the flexibility of management strategies and the preparedness to deal with a variety of unexpected outcomes. We discuss how this approach addresses key cultural and evaluative challenges that policy actors have had in embedding horizon scanning in evidence-based policy processes, and suggest further developments to build confidence in the use of horizon scanning for strategic planning. PMID:27093126

  15. Black Hole Event Horizons and Advection-Dominated Accretion

    NASA Technical Reports Server (NTRS)

    McClintock, Jeffrey; Mushotzky, Richard F. (Technical Monitor)

    2001-01-01

    The XMM data on black-hole X-ray novae are only now becoming available and they have so far not been included in any publications. This work is part of a larger project that makes use of both XMM and Chandra data. Our first publication on the Chandra results is the following: "New Evidence for Black Hole Event Horizons from Chandra" by M.R. Garcia, J.E. McClintock, R. Narayan, P. Callanan, D. Barret and S. Murray (2001, ApJ, 553, L47). Therein we present the luminosities of the two black-hole X-ray novae, GRO J0422+22 and 4U1 543-47, which were observed by Chandra. These results are combined with the luminosities of four additional black-hole X-ray novae, which were observed as part of a Chandra GTO program (PI: S. Murray). The very low, but nonzero, quiescent X-ray luminosities of these black hole binaries is very difficult to understand in the context of standard viscous accretion disk theory. The principal result of this work is that X-ray novae that contain black hole primaries are about 100 times fainter that X-ray novae that contain neutron star primaries. This result had been suggested in earlier work, but the present work very firmly establishes this large luminosity difference. The result is remarkable because the black-hole and the neutron-star systems are believed to be similar in many respects. Most importantly, the mass transfer rate from the secondary star is believed to be very comparable for the two kinds of systems for similar orbital periods. The advection-dominated accretion flow (ADAF) model provides a natural framework for understanding the extraordinarily low luminosities of the black hole systems and the hundred-fold greater luminosities of the neutron star systems. The chief feature of an ADAF is that the heat energy in the accreting gas is trapped in the gas and travels with it, rather than being radiated promptly. Thus the accreting gas reaches the central object with a huge amount of thermal energy. If the accretor is a black hole, the

  16. Extending the search for neutrino point sources with IceCube above the horizon

    SciTech Connect

    IceCube Collaboration; Abbasi, R.

    2009-11-20

    Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This approach improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.

  17. Radiometric performance results of the New Horizons' ALICE UV imaging spectrograph

    NASA Astrophysics Data System (ADS)

    Slater, David C.; Davis, Michael W.; Olkin, Catherine B.; Scherrer, John; Stern, S. Alan

    2005-09-01

    We describe the radiometric performance and calibration results of the New Horizons' ALICE flight model. This ALICE is a lightweight (4.4 kg), low-power (4.4 W), ultraviolet spectrograph based on the ALICE instrument now in flight aboard the European Space Agency's Rosetta spacecraft. Its primary job will be to detect a variety of important atomic and molecular species in Pluto's atmosphere, and to determine their relative abundances so that a complete picture of Pluto's atmospheric composition can be determined for the first time. ALICE will also be used to search for an atmosphere around Pluto's moon, Charon, as well as the Kuiper Belt Objects (KBOs) New Horizons hopes to fly by after Pluto-Charon. Detailed radiometric performance results of the ALICE flight model are presented and discussed.

  18. Acceleration of a static observer near the event horizon of a static isolated black hole

    NASA Astrophysics Data System (ADS)

    Doughty, Noel A.

    1981-05-01

    The magnitude of the proper acceleration of a static observer (or test particle) in a static, isolated, spherically symmetric space-time region is compared with the Newtonian result including the situation in the interior of a perfect-fluid star. The calculation shows that the proper acceleration diverges on the event horizon of a spherically symmetric black hole. The 'surface gravity' of a spherically symmetric black hole, as used in descriptions of the Hawking radiation, is then explicitly related to the accelerations of such static observers, thus providing a simple physical interpretation of the surface gravity and illustrating the global (nonlocal) nature of the event horizon. The calculations are presented in the SI physical equations used almost exclusively by many students and teachers of physics.

  19. [Mapping stakeholders' preferences in prioritization criteria for horizon scanning in healthcare technologies].

    PubMed

    Nascimento, Aline do; Vidal, Avila Teixeira; Almeida, Rosimary Terezinha de

    2016-08-01

    Filtration and prioritization are two basics steps in horizon scanning systems. This article aimed to map stakeholders' preferences in the Brazilian Unified National Health System (SUS) regarding filtration and prioritization criteria. Two filtration criteria (time horizon and innovation) and eight prioritization criteria (relevance to epidemiology, health policies, and clinical practice; potential impact on SUS budget, healthcare providers' costs, and mortality; safety; and legal, ethical, and social aspects) were selected. Multiple correspondence analysis was used to map stakeholders' preferences within and between groups. Two groups were more homogeneous and determinant for selection of prioritization criteria. Stakeholders' professional experience had more influence than institutional affiliations. The approach showed transparent criteria selection and analysis of stakeholders' individual preferences. PMID:27487444

  20. Ion Characteristics in Jupiter's Magnetotail from New Horizon data

    NASA Astrophysics Data System (ADS)

    Hui, Debrup; Su, Yi-Jiun; Elliott, Heather; McComas, Dave; Bagenal, Fran; Crary, Frank

    2009-04-01

    Jupiter's gigantic magnetotail, extending 2500 Jovian radii, is the largest cohesive structure in our solar system. For the first time, NASA's New Horizons (NH) satellite in 2007 traversed almost axially. Data from its onboard SWAP instrument (Solar Wind Around Pluto), which makes coincidence measurements of the ions shows many periodic structures and existence of light and heavy ion species with varying densities in Jupiter's magnetotail plasma population. A better understanding of the physical processes governing such diversity requires knowing the characteristics of the various charged particles present, such as the ion density, velocity, temperature, and pressure. We have developed a 3-dimensional phase-space distribution model by constructing the observed signatures along with the calibration parameters provided by the SWAP team during the NH magnetotail flyby. The model uses five input parameters from SWAP. A 3-D isotropic Maxwellian distribution function is used to estimate density, velocity, and temperature, which is then converted into counts as the instrument measures the count rates. Finally, minimizing the chi-square fitting of our model results in the maximum likelihood of the various parameters. We will show our results from 500-800 RJ.

  1. Air quality implications of the Deepwater Horizon oil spill

    PubMed Central

    Middlebrook, Ann M.; Murphy, Daniel M.; Ahmadov, Ravan; Atlas, Elliot L.; Bahreini, Roya; Blake, Donald R.; Brioude, Jerome; de Gouw, Joost A.; Fehsenfeld, Fred C.; Frost, Gregory J.; Holloway, John S.; Lack, Daniel A.; Langridge, Justin M.; Lueb, Rich A.; McKeen, Stuart A.; Meagher, James F.; Meinardi, Simone; Neuman, J. Andrew; Nowak, John B.; Parrish, David D.; Peischl, Jeff; Perring, Anne E.; Pollack, Ilana B.; Roberts, James M.; Ryerson, Thomas B.; Schwarz, Joshua P.; Spackman, J. Ryan; Warneke, Carsten; Ravishankara, A. R.

    2012-01-01

    During the Deepwater Horizon (DWH) oil spill, a wide range of gas and aerosol species were measured from an aircraft around, downwind, and away from the DWH site. Additional hydrocarbon measurements were made from ships in the vicinity. Aerosol particles of respirable sizes were on occasions a significant air quality issue for populated areas along the Gulf Coast. Yields of organic aerosol particles and emission factors for other atmospheric pollutants were derived for the sources from the spill, recovery, and cleanup efforts. Evaporation and subsequent secondary chemistry produced organic particulate matter with a mass yield of 8 ± 4% of the oil mixture reaching the water surface. Approximately 4% by mass of oil burned on the surface was emitted as soot particles. These yields can be used to estimate the effects on air quality for similar events as well as for this spill at other times without these data. Whereas emission of soot from burning surface oil was large during the episodic burns, the mass flux of secondary organic aerosol to the atmosphere was substantially larger overall. We use a regional air quality model to show that some observed enhancements in organic aerosol concentration along the Gulf Coast were likely due to the DWH spill. In the presence of evaporating hydrocarbons from the oil, NOx emissions from the recovery and cleanup operations produced ozone. PMID:22205764

  2. Einstein Revisited - Gravity in Curved Spacetime Without Event Horizons

    NASA Astrophysics Data System (ADS)

    Leiter, Darryl

    2000-04-01

    In terms of covariant derivatives with respect to flat background spacetimes upon which the physical curved spacetime is imposed (1), covariant conservation of energy momentum requires, via the Bianchi Identity, that the Einstein tensor be equated to the matter energy momentum tensor. However the Einstein tensor covariantly splits (2) into two tensor parts: (a) a term proportional to the gravitational stress energy momentum tensor, and (b) an anti-symmetric tensor which obeys a covariant 4-divergence identity called the Freud Identity. Hence covariant conservation of energy momentum requires, via the Freud Identity, that the Freud tensor be equal to a constant times the matter energy momentum tensor. The resultant field equations (3) agree with the Einstein equations to first order, but differ in higher orders (4) such that black holes are replaced by "red holes" i.e., dense objects collapsed inside of their photon orbits with no event horizons. (1) Rosen, N., (1963), Ann. Phys. v22, 1; (2) Rund, H., (1991), Alg. Grps. & Geom. v8, 267; (3) Yilmaz, Hl, (1992), Nuo. Cim. v107B, 946; (4) Roberstson, S., (1999),Ap.J. v515, 365.

  3. Air quality implications of the Deepwater Horizon oil spill.

    PubMed

    Middlebrook, Ann M; Murphy, Daniel M; Ahmadov, Ravan; Atlas, Elliot L; Bahreini, Roya; Blake, Donald R; Brioude, Jerome; de Gouw, Joost A; Fehsenfeld, Fred C; Frost, Gregory J; Holloway, John S; Lack, Daniel A; Langridge, Justin M; Lueb, Rich A; McKeen, Stuart A; Meagher, James F; Meinardi, Simone; Neuman, J Andrew; Nowak, John B; Parrish, David D; Peischl, Jeff; Perring, Anne E; Pollack, Ilana B; Roberts, James M; Ryerson, Thomas B; Schwarz, Joshua P; Spackman, J Ryan; Warneke, Carsten; Ravishankara, A R

    2012-12-11

    During the Deepwater Horizon (DWH) oil spill, a wide range of gas and aerosol species were measured from an aircraft around, downwind, and away from the DWH site. Additional hydrocarbon measurements were made from ships in the vicinity. Aerosol particles of respirable sizes were on occasions a significant air quality issue for populated areas along the Gulf Coast. Yields of organic aerosol particles and emission factors for other atmospheric pollutants were derived for the sources from the spill, recovery, and cleanup efforts. Evaporation and subsequent secondary chemistry produced organic particulate matter with a mass yield of 8 ± 4% of the oil mixture reaching the water surface. Approximately 4% by mass of oil burned on the surface was emitted as soot particles. These yields can be used to estimate the effects on air quality for similar events as well as for this spill at other times without these data. Whereas emission of soot from burning surface oil was large during the episodic burns, the mass flux of secondary organic aerosol to the atmosphere was substantially larger overall. We use a regional air quality model to show that some observed enhancements in organic aerosol concentration along the Gulf Coast were likely due to the DWH spill. In the presence of evaporating hydrocarbons from the oil, NO(x) emissions from the recovery and cleanup operations produced ozone. PMID:22205764

  4. An Experiment to Detect Lunar Horizon Glow with the Lunar Orbit Laser Altimeter Laser Ranging Telescope

    NASA Astrophysics Data System (ADS)

    Smith, David E.; Zuber, Maria T.; Barker, Michael; Mazarico, Erwan; Neumann, Gregory A.; McClanahan, Timothy P.; Sun, Xiaoli

    2016-04-01

    Lunar horizon glow (LHG) was an observation by the Apollo astronauts of a brightening of the horizon around the time of sunrise. The effect has yet to be fully explained or confirmed by instruments on lunar orbiting spacecraft despite several attempts. The Lunar Reconnaissance Orbiter (LRO) spacecraft carries the laser altimeter (LOLA) instrument which has a 2.5 cm aperture telescope for Earth-based laser ranging (LR) mounted and bore-sighted with the high gain antenna (HGA). The LR telescope is connected to LOLA by a fiber-glass cable to one of its 5 detectors. For the LGH experiments the LR telescope is pointed toward the horizon shortly before lunar sunrise with the intent of observing any forward scattering of sunlight due to the presence of dust or particles in the field of view. Initially, the LR telescope is pointed at the dark lunar surface, which provides a measure of the dark count, and moves toward the lunar limb so as to measure the brightness of the sky just above the lunar limb immediately prior to lunar sunrise. At no time does the sun shine directly into the LR telescope, although the LR telescope is pointed as close to the sun as the 1.75-degree field of view permits. Experiments show that the LHG signal seen by the astronauts can be detected with a four-second integration of the noise counts.

  5. Cardiovascular Effects of 1 Year of Alagebrium and Endurance Exercise Training in Healthy Older Individuals

    PubMed Central

    Fujimoto, Naoki; Hastings, Jeffrey L.; Carrick-Ranson, Graeme; Shafer, Keri M.; Shibata, Shigeki; Bhella, Paul S.; Abdullah, Shuaib M.; Barkley, Kyler W.; Adams-Huet, Beverley; Boyd, Kara N.; Livingston, Sheryl A.; Palmer, Dean; Levine, Benjamin D.

    2014-01-01

    Background Lifelong exercise training maintains a youthful compliance of the left ventricle (LV), whereas a year of exercise training started later in life fails to reverse LV stiffening, possibly because of accumulation of irreversible advanced glycation end products. Alagebrium breaks advanced glycation end product crosslinks and improves LV stiffness in aged animals. However, it is unclear whether a strategy of exercise combined with alagebrium would improve LV stiffness in sedentary older humans. Methods and Results Sixty-two healthy subjects were randomized into 4 groups: sedentary+placebo; sedentary+alagebrium (200 mg/d); exercise+placebo; and exercise+alagebrium. Subjects underwent right heart catheterization to define LV pressure–volume curves; secondary functional outcomes included cardiopulmonary exercise testing and arterial compliance. A total of 57 of 62 subjects (67±6 years; 37 f/20 m) completed 1 year of intervention followed by repeat measurements. Pulmonary capillary wedge pressure and LV end-diastolic volume were measured at baseline, during decreased and increased cardiac filling. LV stiffness was assessed by the slope of LV pressure–volume curve. After intervention, LV mass and end-diastolic volume increased and exercise capacity improved (by ≈8%) only in the exercise groups. Neither LV mass nor exercise capacity was affected by alagebrium. Exercise training had little impact on LV stiffness (training×time effect, P=0.46), whereas alagebrium showed a modest improvement in LV stiffness compared with placebo (medication×time effect, P=0.04). Conclusions Alagebrium had no effect on hemodynamics, LV geometry, or exercise capacity in healthy, previously sedentary seniors. However, it did show a modestly favorable effect on age-associated LV stiffening. PMID:24130005

  6. Robot-assisted laparoscopic pyeloplasty: minimum 1-year follow-up

    NASA Astrophysics Data System (ADS)

    Patel, Vipul; Thaly, Rahul; Shah, Ketul

    2007-02-01

    Objectives: To evaluate the feasibility and efficacy of robotic-assisted laparoscopic pyeloplasty. Laparoscopic pyeloplasty has been shown to have a success rate comparable to that of the open surgical approach. However, the steep learning curve has hindered its acceptance into mainstream urologic practice. The introduction of robotic assistance provides advantages that have the potential to facilitate precise dissection and intracorporeal suturing. Methods: A total of 50 patients underwent robotic-assisted laparoscopic dismembered pyeloplasty. A four-trocar technique was used. Most patients were discharged home on day 1, with stent removal at 3 weeks. Patency of the ureteropelvic junction was assessed in all patients with mercaptotriglycylglycine Lasix renograms at 1, 3, 6, 9, and 12 months, then every 6 months for 1 year, and then yearly. Results: Each patient underwent a successful procedure without open conversion or transfusion. The average estimated blood loss was 40 ml. The operative time averaged 122 minutes (range 60 to 330) overall. Crossing vessels were present in 30% of the patients and were preserved in all cases. The time for the anastomosis averaged 20 minutes (range 10 to 100). Intraoperatively, no complications occurred. Postoperatively, the average hospital stay was 1.1 days. The stents were removed at an average of 20 days (range 14 to 28) postoperatively. The average follow-up was 11.7 months; at the last follow-up visit, each patient was doing well. Of the 50 patients, 48 underwent one or more renograms, demonstrating stable renal function, improved drainage, and no evidence of recurrent obstruction. Conclusions: Robotic-assisted laparoscopic pyeloplasty is a feasible technique for ureteropelvic junction reconstruction. The procedure provides a minimally invasive alternative with good short-term results.

  7. A 1-Year Study on the Detection of Human Enteric Viruses in New Caledonia.

    PubMed

    Kaas, Laetitia; Gourinat, Ann-Claire; Urbès, Florence; Langlet, Jérémie

    2016-03-01

    Human enteric viruses occur in high concentrations in wastewater and can contaminate receiving environmental waters. Due to the lack of data on the prevalence of enteric viruses in New Caledonia, the presence and the concentrations of enteric viruses in wastewater and seawater were determined. Untreated wastewater and seawater samples were collected monthly for 1 year from a wastewater treatment plant (WWTP) and from the WWTP's outlet, located directly on a popular recreational beach. Samples were tested for norovirus genogroups I and II (NoV GI and GII), astroviruses (AsV), sapoviruses (SaV), enteroviruses (EV), hepatitis A viruses (HAV), rotaviruses (RoV), human adenoviruses (HAdV) and human polyomaviruses (HPyV). To support these data, faecal samples from cases of gastroenteritis were tested for the first time for NoV and detected in the population. NoV GI, NoV GII, EV, SaV, HAdV and HPyV were detected in all wastewaters, RoV in 75% and AsV in 67%. HAV were not detected in wastewater. Overall, 92% of seawater samples were positive for at least one virus. HPyV were detected most frequently in 92% of samples and at concentrations up to 7.7 × 10(3) genome copies/L. NoV GI, NoV GII, EV, SaV, RoV and HAdV were found in 33, 66, 41, 33, 16 and 66% of seawater samples, respectively. AsV were not detected in seawater. This study reports for the first time the presence of NoV and other enteric viruses in New Caledonia and highlights the year-round presence of enteric viruses in the seawater of a popular beach. PMID:26670603

  8. Fate and Speciation of Gasoline-Derived Lead in Organic Horizons of the Northeastern USA

    SciTech Connect

    Kaste,J.; Bostick, B.; Friedland, A.; Schroth, A.; Siccama, T.

    2006-01-01

    Although legislation in the late 1970s significantly reduced atmospheric lead (Pb) inputs to ecosystems in North America, organic (O) horizons in forests of the northeastern USA still contain up to 30 kg of gasoline-derived Pb ha{sup -1}. The residence time, geochemical behavior, and fate of this contaminant Pb in soils is poorly understood. Here we use forest floor time series data and synchrotron-based X-ray techniques to examine the mobility and speciation of Pb in O horizons collected from remote sites across the northeastern USA. At high elevation (>800 m) sites in Vermont and New York, samples collected from similar locations in 1980, 1990, and early 2000 had indistinguishable Pb contents, ranging ({+-}1{sigma}) from 11 to 29 kg Pb ha{sup -1}. However, at lower elevation and lower latitude sites with mixed vegetation, significant decreases in Pb amount were observed during the two-decade study period. Lower elevation sites ranged from 10 to 20 kg Pb ha{sup -1} in 1980, and from 2 to 10 kg Pb ha{sup -1} 20 yr later. Lead-enriched soil grains were determined to be amorphous with microfocused X-ray diffraction, and Pb concentrations correlated well with Fe on maps generated via microfocused X-ray fluorescence. Bulk Pb L{sub III}-edge X-ray absorption spectroscopy of coniferous O horizon samples indicate that Pb is binding to iron-rich soil particles by inner-sphere complexes, most likely to amorphous Fe oxides. Based on our paired regional and microscopic observations, we conclude that Pb is strongly retained in well-drained O horizons, and mobility is governed by decomposition and colloidal transport.

  9. Time?

    NASA Astrophysics Data System (ADS)

    Amoroso, Richard L.

    2013-09-01

    The concept of time in the `clockwork' Newtonian world was irrelevant; and has generally been ignored until recently by several generations of physicists since the implementation of quantum mechanics. We will set aside the utility of time as a property relating to physical calculations of events relating to a metrics line element or as an aspect of the transformation of a particles motion/interaction in a coordinate system or in relation to thermodynamics etc., i.e. we will discard all the usual uses of time as a concept used to circularly define physical parameters in terms of other physical parameters; concentrating instead on time as an aspect of the fundamental cosmic topology of our virtual reality especially as it inseparably relates to the nature and role of the observer in natural science.

  10. Cognitive functions over the course of 1 year in multiple sclerosis patients treated with disease modifying therapies

    PubMed Central

    Utz, Kathrin S.; Lee, De-Hyung; Lämmer, Alexandra; Waschbisch, Anne; Linker, Ralf A.; Schenk, Thomas

    2016-01-01

    Objectives: Disease-modifying therapies (DMTs) are applied to delay or prevent disease progression in multiple sclerosis (MS). While this has mostly been proven for physical symptoms, available studies regarding long-term effects of DMTs on cognitive functions are rare and sometimes inconsistent due to methodological shortcomings. Particularly in the case of fingolimod, comprehensive data on cognitive functions are not yet available. Therefore, we set out to reliably assess cognitive functions in patients with relapsing–remitting MS (RRMS) treated with DMTs over 1 year. Methods: Cognitive functions were assessed with eight tests at three timepoints: baseline, 6-month follow up and 12-month follow up. First, we investigated whether the stability of cognitive functions (i.e. not falling below the 5% cut-off in more than one test) over 1 year in RRMS patients (n = 41) corresponds to the stability in healthy individuals (n = 40) of a previous study. Second, we compared the percentage of declined and improved patients in the different tests. Third, we compared patients treated with fingolimod (n = 22) with patients treated with natalizumab (n = 11) with regard to cognitive stability. Fourth, based on the patient data, the Reliable Change Index was applied to compute cut-offs for reliable cognitive change. Results: Approximately 75% of RRMS patients treated with DMTs remained stable over the course of 1 year. The Paced Auditory Serial Addition Test (PASAT) and the Spatial Recall Test (SPART), produced improvements in 12.5% and 30.6%, respectively, probably due to practice effects. Patients treated with fingolimod did not differ from patients treated with natalizumab with regard to cognitive stability. Conclusions: Cognitive functions remain relatively stable under DMT treatment over 1 year, irrespective of the type of medication. Furthermore, the tests PASAT and SPART should be interpreted cautiously in studies examining performance changes over time. The provided RCI

  11. Intrinsic geometry of a tidally deformed Kerr horizon

    NASA Astrophysics Data System (ADS)

    Poisson, Eric

    2013-04-01

    The intrinsic metric of a tidally deformed black-hole horizon can be presented in a coordinate system adapted to the horizon's null generators, with one coordinate acting as a running parameter along each generator, and two coordinates acting as constant generator labels. The metric is invariant under reparametrizations of the generators, and as such the horizon's intrinsic geometry is known to be gauge invariant. We consider a Kerr black hole deformed by a slowly-evolving external tidal field, and describe the intrinsic geometry of its event horizon in terms of the electric and magnetic tidal moments that characterize the tidal environment. When the black hole is slowly rotating, the horizon's geometry can be described in terms of a deviation from an otherwise spherical surface, and the deformation can be characterized by gauge invariant Love numbers. Some aspects of this tidal deformation have direct analogues in Newtonian physics. Some do not, and I will describe the similarities and differences between the tidal deformation of rotating black holes in general relativity and rotating fluid bodies in Newtonian physics.

  12. Quantization of Horizon Entropy and the Thermodynamics of Spacetime

    NASA Astrophysics Data System (ADS)

    Skákala, Jozef

    2014-06-01

    This is a review of my work published in the papers of Skakala (JHEP 1201:144, 2012; JHEP 1206:094, 2012) and Chirenti et al. (Phys. Rev. D 86:124008, 2012; Phys. Rev. D 87:044034, 2013). It offers a more detailed discussion of the results than the accounts in those papers, and it links my results to some conclusions recently reached by other authors. It also offers some new arguments supporting the conclusions in the cited articles. The fundamental idea of this work is that the semiclassical quantization of the black hole entropy, as suggested by Bekenstein (Phys. Rev. D 7:2333-2346, 1973), holds (at least) generically for the spacetime horizons. We support this conclusion by two separate arguments: (1) we generalize Bekenstein's lower bound on the horizon area transition to a much wider class of horizons than only the black-hole horizon, and (2) we obtain the same entropy spectra via the asymptotic quasi-normal frequencies of some particular spherically symmetric multi-horizon spacetimes (in the way proposed by Maggiore (Phys. Rev. Lett. 100:141301, 2008)). The main result of this paper supports the conclusions derived by Kothawalla et al. (Phys. Rev. D 78:104018, 2008) and Kwon and Nam (Class. Quant. Grav. 28:035007, 2011), on the basis of different arguments.

  13. Dynamical horizon entropy and equilibrium thermodynamics of generalized gravity theories

    SciTech Connect

    Wu Shaofeng; Ge Xianhui; Yang Guohong; Zhang Pengming

    2010-02-15

    We study the relation between the thermodynamics and field equations of generalized gravity theories on the dynamical trapping horizon with sphere symmetry. We assume the entropy of a dynamical horizon as the Noether charge associated with the Kodama vector and point out that it satisfies the second law when a Gibbs equation holds. We generalize two kinds of Gibbs equations to Gauss-Bonnet gravity on any trapping horizon. Based on the quasilocal gravitational energy found recently for f(R) gravity and scalar-tensor gravity in some special cases, we also build up the Gibbs equations, where the nonequilibrium entropy production, which is usually invoked to balance the energy conservation, is just absorbed into the modified Wald entropy in the Friedmann-Robertson-Walker spacetime with slowly varying horizon. Moreover, the equilibrium thermodynamic identity remains valid for f(R) gravity in a static spacetime. Our work provides an alternative treatment to reinterpret the nonequilibrium correction and supports the idea that the horizon thermodynamics is universal for generalized gravity theories.

  14. Restoration of the Ellipsoid Zone and Visual Prognosis at 1 Year after Surgical Macular Hole Closure

    PubMed Central

    Hasebe, Hiruma; Matsuoka, Naoki; Terashima, Hiroko; Sasaki, Ryo; Ueda, Eriko; Fukuchi, Takeo

    2016-01-01

    Purpose. To evaluate the restoration of the ellipsoid zone (EZ) and its influence on visual prognosis 1 year after surgical macular hole (MH) closure. Method. Subjects were patients with stage 2, 3, or 4 idiopathic MH who underwent primary vitrectomy that resulted in successful hole closure. Nineteen eyes with both EZ disruption with foveal detachment and a continuous external limiting membrane on optical coherence tomography during the early postoperative period were included in this study. Result. EZ disruption was restored in 10 eyes (53%, Group A) and remained in 9 eyes (47%, Group B) at 1 year after surgery. In Group B, the diameter of the residual EZ disruption was 54.7 ± 33.1 μm. LogMAR visual acuity (VA) 1 year after surgery was significantly better than preoperative VA in each group (Group A: −0.007 ± 0.102; P < 0.001; Group B: 0.051 ± 0.148; P < 0.001), but there was no significant difference between the 2 groups (P = 0.332). There was no significant correlation between logMAR VA and EZ disruption diameter at 1 year after surgery. Conclusion. EZ was restored in 53% of eyes at 1 year after surgical closure of idiopathic MH. Mean residual EZ disruption diameter was 54.7 ± 33.1 μm. Neither resolved nor residual EZ disruption influenced postoperative VA. PMID:26941999

  15. Representation to the accident and emergency department within 1-year of a fractured neck of femur

    PubMed Central

    2011-01-01

    Background The fractured neck of femur (NOF) is a leading cause of morbidity and mortality. The mortality attendant upon such fractures is 10% at 1 month and 30% at one year with a cost to the NHS of £1.4 billion annually. This retrospective study sought to examine rates and prevailing trends in representation to A&E in the year following a NOF fracture in an attempt to identify the leading causes behind the morbidity and mortality associated with this fracture. Methods 1108 patients who suffered a fractured NOF between 1 January 2002 and 31 December 2007 were identified from a University Hospital A&E database. This database was then used to identify those patients who represented within 1-year following the initial fracture. The presenting complaint, provisional diagnosis and the outcome of this presentation were identified at this time. Results 234 patients (21%) returned to A&E on 368 occasions in the year following a hip fracture. 77% (284/368) of these presentations necessitated admission. Falls, infection and fracture were the leading causes of representation. Falls accounted for 20% (57/284) of admissions; 20.7% of patients were admitted because of a fracture, while 56.6% of admissions were for medical ailments of which infection was the chief precipitant (28% (45/161)). Discussion The causes for representation are varied and multifactorial. The results of this study suggest that some of those events or ailments necessitating readmission may be obviated and potentially reduced by interventions that can be instituted during the primary admission and continued following discharge. PMID:22189063

  16. Effectiveness of counselling over 1 year on changes in lifestyle and coronary heart disease risk factors.

    PubMed

    Nisbeth, O; Klausen, K; Andersen, L B

    2000-05-01

    Many have studied the effects of different lifestyles on disease, mortality or risk factors for a disease, but little is known about how behaviour is changed in the population. We studied the need for counselling and its effect on willingness and ability to change lifestyle, and subsequent changes in CHD risk factors. All 152 male employees in a computer company, 25-45 years of age, were invited to participate. Subjects were randomized into an intervention group (I-group) and a control group. The I-group was divided into subgroups based on baseline behaviour and risk factor status. Changes were evaluated after 1 year. After an initial health examination, participants from the I-group were counselled at baseline and after 5 months. Eighty-five (56%) males participated. Twenty-nine were assigned to a control group and 56 to an intervention group (I-group) (dropout = 8). An exercise group (E-group) was advised to exercise aerobically three times/week, a diet group to reduce the intake of saturated fat and increase fish products, and smokers to quit smoking. Forty subjects were recommended one or more behavioural changes and eight had no need. Thirty-four were willing to make behavioural changes. Compared to the control group, the fitness level increased (P < 0.01) and body weight decreased in the I-group (P < 0.05). It may be concluded that individual counselling promotes regular exercise with subsequent improvements in CHD risk factors. The diet- and smoking counselling models were less successful in terms of adherence. PMID:10771366

  17. Radio Occultation Measurements of Pluto’s Atmosphere with New Horizons

    NASA Astrophysics Data System (ADS)

    Hinson, David P.; Linscott, Ivan; Tyler, Len; Bird, Mike; Paetzold, Martin; Strobel, Darrell; Summers, Mike; Woods, Will; Stern, Alan; Weaver, Hal; Olkin, Cathy; Young, Leslie; Ennico, Kimberly; Gladstone, Randy; Greathouse, Tommy; Kammer, Josh; Parker, Alex; Parker, Joel; Retherford, Kurt; Schindhelm, Eric; Singer, Kelsi; Steffl, Andrew; Tsang, Con; Versteeg, Maarten

    2015-11-01

    The reconnaissance of the Pluto System by New Horizons included radio occultations at both Pluto and Charon. This talk will present the latest results from the Pluto occultation. The REX instrument onboard New Horizons received and recorded uplink signals from two 70-m antennas and two 34-m antennas of the NASA Deep Space Network - each transmitting 20 kW at 4.2-cm wavelength - during a diametric occultation by Pluto. At the time this was written only a short segment of data at occultation entry (193°E, 17°S) was available for analysis. The REX measurements extend unequivocally to the surface, providing the first direct measure of the surface pressure and the temperature structure in Pluto’s lower atmosphere. Data from occultation exit (16°E, 15°N) are scheduled to arrive on the ground in late August 2015. Those observations will yield an improved estimate of the surface pressure, a second temperature profile, and a measure of the diameter of Pluto with a precision of a few hundred meters. This work is supported by the NASA New Horizons Mission.

  18. Interacting entropy-corrected holographic dark energy with apparent horizon as an infrared cutoff

    NASA Astrophysics Data System (ADS)

    Khodam-Mohammadi, A.; Malekjani, M.

    2012-05-01

    In this work we consider the entropy-corrected version of interacting holographic dark energy (HDE), in the non-flat universe enclosed by apparent horizon. Two corrections of entropy so-called logarithmic `LEC' and power-law `PLEC' in HDE model with apparent horizon as an IR-cutoff are studied. The ratio of dark matter to dark energy densities u, equation of state parameter w D and deceleration parameter q are obtained. We show that the cosmic coincidence problem is solved for interacting models. By studying the effect of interaction in EoS parameter of both models, we see that the phantom divide may be crossed and also understand that the interacting models can drive an acceleration expansion at the present and future, while in non-interacting case, this expansion can happen only at the early time. The graphs of deceleration parameter for interacting models, show that the present acceleration expansion is preceded by a sufficiently long period deceleration at past. Moreover, the thermodynamical interpretation of interaction between LECHDE and dark matter is described. We obtain a relation between the interaction term of dark components and thermal fluctuation in a non-flat universe, bounded by the apparent horizon. In limiting case, for ordinary HDE, the relation of interaction term versus thermal fluctuation is also calculated.

  19. Atmospheric transport of neutrons and gamma rays from near-horizon nuclear detonations

    SciTech Connect

    Byrd, R.C.; Heerema, B.D.

    1996-03-01

    This report continues a study of the transport of neutrons and rays from nuclear detonations at high altitudes to a set of detectors, with an emphasis on the limiting case of sources even beyond the horizon. To improve the calculational efficiency, the standard arrangement of a single source with multiple detectors is transformed to an equivalent one with a single detector and sources at multiple locations. Particular attention is paid to the critical problem of transport at near-horizon angles in an atmosphere whose density decreases exponentially with altitude. As a check, calculations for this region are made using both analytical and Monte Carlo approaches. For sources approaching the horizon, the fluence of gamma rays and neutrons reaching the detector drops gradually as the increasing column density attenuates the direct, unscattered fluence. Near the grazing angle, the direct fluence plummets, but the scattered component continues to decrease slowly and remains observable. Over this range, the timedependent flux of direct-plus-scattered gamma rays changes dramatically in both shape and magnitude, but it probably remains distinct from typical natural backgrounds. The neutron time-of-flight spectrum is dominated by scattering and reflects only the most important aspects of the original source spectrum; its most obvious features are a prominent low-energy tail and the resonance structure produced by nuclear interactions in the atmosphere. In some cases, the fluence of secondary gamma rays produced by these interactions may be larger than that from the source itself.

  20. The late Barremian Halimedides horizon of the Dolomites (Southern Alps, Italy)

    PubMed Central

    Lukeneder, Alexander; Uchman, Alfred; Gaillard, Christian; Olivero, Davide

    2012-01-01

    A new trace fossil marker level, the Halimedides horizon, is proposed for the Lower Cretaceous pelagic to hemipelagic succession of the Puez area (Southern Alps, Italy). The horizon occurs in the middle part of the late Barremian Gerhardtia sartousiana Zone (Gerhardtia sartousiana Subzone). It is approximately 20 cm thick and restricted to the uppermost part of the Puez Limestone Member (marly limestones; Hauterivian–Barremian; Puez Formation). It is fixed to the top 20 cm of bed P1/204. The grey–whitish limestone bed of the G. sartousiana Zone is penetrated by Aptian red marls–siltstones of the Redbed Member. The horizon is documented for the first time from the Southern Alps, including the Dolomites, and can be correlated with other Mediterranean localities. The trace fossil assemblage of this marker bed with the co-occurrence of Halimedides, Spongeliomorpha and Zoophycos sheds light on the Lower Cretaceous sedimentological history and current system of the Puez area within the Dolomites. It also highlights the palaeoenvironmental evolution of basins and plateaus and provides insights into the late Barremian interval. PMID:27087717

  1. Stationary holographic plasma quenches and numerical methods for non-killing horizons.

    PubMed

    Figueras, Pau; Wiseman, Toby

    2013-04-26

    We explore use of the harmonic Einstein equations to numerically find stationary black holes where the problem is posed on an ingoing slice that extends into the interior of the black hole. Requiring no boundary conditions at the horizon beyond smoothness of the metric, this method may be applied for horizons that are not Killing. As a nontrivial illustration we find black holes which, via AdS-CFT, describe a time-independent CFT plasma flowing through a static spacetime which asymptotes to Minkowski in the flow's past and future, with a varying spatial geometry in between. These are the first nonperturbative examples of stationary black holes which do not have Killing horizons. When the CFT spacetime slowly varies, the CFT stress tensor derived from gravity is well described by viscous hydrodynamics. For fast variation it is not, and the solutions are stationary analogs of dynamical quenches, with the plasma being suddenly driven out of equilibrium. We find evidence these flows become unstable for sufficiently strong quenches, and speculate the instability may be turbulent. PMID:23679705

  2. Multiple microtektite horizons in upper eocene marine sediments: no evidence for mass extinctions.

    PubMed

    Keller, G; D'Hondt, S; Vallier, T L

    1983-07-01

    Microtektites have been recovered from three horizons in eight middle Eocene to middle Oligocene marine sediment sequences. Five of these occurrences are coeval and of latest Eocene age (37.5 to 38.0 million years ago); three are coeval and of early late Eocene age (38.5 to 39.5 million years ago); and three are of middle Oligocene age (31 to 32 million years ago). In addition, rare probable microtektites have been found in sediments with ages of about 36.0 to 36.5 million years. The microtektite horizon at 37.5 to 38.0 million years can be correlated with the North American tektite-strewn field, which has a fission track age (minimum) of 34 to 35 million years and a paleomagnetic age of 37.5 to 38.0 million years. There is no evidence for mass faunal extinctions at any of the microtektite horizons. Many of the distinct faunal changes that occurred in the middle Eocene to middle Oligocene can be related to the formation of the Antarctic ice sheet and the associated cooling phenomena and intensification of bottom currents that led to large-scale dissolution of calcium carbonate and erosion, which created areally extensive hiatuses in the deep-sea sediment records. The occurrence of microtektite horizons of several ages and the lack of evidence for faunal extinctions suggest that the effects of extraterrestrial bolide impacts may be unimportant in the biologic realm during middle Eocene to middle Oligocene time. PMID:17769212

  3. A disconnect between O horizon and mineral soil carbon - Implications for soil C sequestration

    SciTech Connect

    Garten Jr, Charles T

    2009-01-01

    Changing inputs of carbon to soil is one means of potentially increasing carbon sequestration in soils for the purpose of mitigating projected increases in atmospheric CO{sub 2} concentrations. The effect of manipulations of aboveground carbon input on soil carbon storage was tested in a temperate, deciduous forest in east Tennessee, USA. A 4.5-year experiment included exclusion of aboveground litterfall and supplemental litter additions (three times ambient) in an upland and a valley that differed in soil nitrogen availability. The estimated decomposition rate of the carbon stock in the O horizon was greater in the valley than in the upland due to higher litter quality (i.e., lower C/N ratios). Short-term litter exclusion or addition had no effect on carbon stock in the mineral soil, measured to a depth of 30 cm, or the partitioning of carbon in the mineral soil between particulate- and mineral-associated organic matter. A two-compartment model was used to interpret results from the field experiments. Field data and a sensitivity analysis of the model were consistent with little carbon transfer between the O horizon and the mineral soil. Increasing aboveground carbon input does not appear to be an effective means of promoting carbon sequestration in forest soil at the location of the present study because a disconnect exists in carbon dynamics between O horizon and mineral soil. Factors that directly increase inputs to belowground soil carbon, via roots, or reduce decomposition rates of organic matter are more likely to benefit efforts to increase carbon sequestration in forests where carbon dynamics in the O horizon are uncoupled from the mineral soil.

  4. A disconnect between O horizon and mineral soil carbon - Implications for soil C sequestration

    NASA Astrophysics Data System (ADS)

    Garten, Charles T., Jr.

    2009-03-01

    Changing inputs of carbon to soil is one means of potentially increasing carbon sequestration in soils for the purpose of mitigating projected increases in atmospheric CO 2 concentrations. The effect of manipulations of aboveground carbon input on soil carbon storage was tested in a temperate, deciduous forest in east Tennessee, USA. A 4.5-year experiment included exclusion of aboveground litterfall and supplemental litter additions (three times ambient) in an upland and a valley that differed in soil nitrogen availability. The estimated decomposition rate of the carbon stock in the O horizon was greater in the valley than in the upland due to higher litter quality (i.e., lower C/N ratios). Short-term litter exclusion or addition had no effect on carbon stock in the mineral soil, measured to a depth of 30 cm, or the partitioning of carbon in the mineral soil between particulate- and mineral-associated organic matter. A two-compartment model was used to interpret results from the field experiments. Field data and a sensitivity analysis of the model were consistent with little carbon transfer between the O horizon and the mineral soil. Increasing aboveground carbon input does not appear to be an effective means of promoting carbon sequestration in forest soil at the location of the present study because a disconnect exists in carbon dynamics between O horizon and mineral soil. Factors that directly increase inputs to belowground soil carbon, via roots, or reduce decomposition rates of organic matter are more likely to benefit efforts to increase carbon sequestration in forests where carbon dynamics in the O horizon are uncoupled from the mineral soil.

  5. Asymptotically Lifshitz spacetimes with universal horizons in (1 +2 ) dimensions

    NASA Astrophysics Data System (ADS)

    Basu, Sayandeb; Bhattacharyya, Jishnu; Mattingly, David; Roberson, Matthew

    2016-03-01

    Hořava gravity theory possesses global Lifshitz space as a solution and has been conjectured to provide a natural framework for Lifshitz holography. We derive the conditions on the two-derivative Hořava gravity Lagrangian that are necessary for static, asymptotically Lifshitz spacetimes with flat transverse dimensions to contain a universal horizon, which plays a similar thermodynamic role as the Killing horizon in general relativity. Specializing to z =2 in 1 +2 dimensions, we then numerically construct such regular solutions over the whole spacetime. We calculate the mass for these solutions and show that, unlike the asymptotically anti-de Sitter case, the first law applied to the universal horizon is straightforwardly compatible with a thermodynamic interpretation.

  6. Thermodynamics of event horizons in (2+1)-dimensional gravity

    SciTech Connect

    Reznik, B. )

    1992-03-15

    Although gravity in 2+1 dimensions is very different in nature from gravity in 3+1 dimensions, it is shown that the laws of thermodynamics for event horizons can be manifested also for (2+1)-dimensional gravity. The validity of the classical laws of horizon mechanics is verified in general and exemplified for the (2+1)-dimensional analogues of Reissner-Nordstroem and Schwarzschild--de Sitter spacetimes. We find that the entropy is given by 1/4{ital L}, where {ital L} is the length of the horizon. A consequence of having consistent thermodynamics is that the second law fixes the sign of Newton's constant to be positive.

  7. Black hole thermodynamics from near-horizon conformal quantum mechanics

    SciTech Connect

    Camblong, Horacio E.; Ordonez, Carlos R.

    2005-05-15

    The thermodynamics of black holes is shown to be directly induced by their near-horizon conformal invariance. This behavior is exhibited using a scalar field as a probe of the black hole gravitational background, for a general class of metrics in D spacetime dimensions (with D{>=}4). The ensuing analysis is based on conformal quantum mechanics, within a hierarchical near-horizon expansion. In particular, the leading conformal behavior provides the correct quantum statistical properties for the Bekenstein-Hawking entropy, with the near-horizon physics governing the thermodynamics from the outset. Most importantly: (i) this treatment reveals the emergence of holographic properties; (ii) the conformal coupling parameter is shown to be related to the Hawking temperature; and (iii) Schwarzschild-like coordinates, despite their 'coordinate singularity', can be used self-consistently to describe the thermodynamics of black holes.

  8. Deepwater Horizon oil spill monitoring using airborne multispectral infrared imagery

    NASA Astrophysics Data System (ADS)

    Shen, Sylvia S.; Lewis, Paul E.

    2011-06-01

    On April 28, 2010, the Environmental Protection Agency's (EPA) Airborne Spectral Photometric Environmental Collection Technology (ASPECT) aircraft was deployed to Gulfport, Mississippi to provide airborne remotely sensed air monitoring and situational awareness data and products in response to the Deepwater Horizon oil spill disaster. The ASPECT aircraft was released from service on August 9, 2010 after having flown over 85 missions that included over 325 hours of flight operation. This paper describes several advanced analysis capabilities specifically developed for the Deepwater Horizon mission to correctly locate, identify, characterize, and quantify surface oil using ASPECT's multispectral infrared data. The data products produced using these advanced analysis capabilities provided the Deepwater Horizon Incident Command with a capability that significantly increased the effectiveness of skimmer vessel oil recovery efforts directed by the U.S. Coast Guard, and were considered by the Incident Command as key situational awareness information.

  9. FOAM: Expanding the horizons of climate modeling

    SciTech Connect

    Tobis, M.; Foster, I.T.; Schafer, C.M.

    1997-10-01

    We report here on a project that expands the applicability of dynamic climate modeling to very long time scales. The Fast Ocean Atmosphere Model (FOAM) is a coupled ocean atmosphere model that incorporates physics of interest in understanding decade to century time scale variability. It addresses the high computational cost of this endeavor with a combination of improved ocean model formulation, low atmosphere resolution, and efficient coupling. It also uses message passing parallel processing techniques, allowing for the use of cost effective distributed memory platforms. The resulting model runs over 6000 times faster than real time with good fidelity, and has yielded significant results.

  10. Electrodynamics with a Future Conformal Horizon

    SciTech Connect

    Ibison, Michael

    2010-12-22

    We investigate the impact of singularities occurring at future times in the Friedmann equations expressed in conformal coordinates to determine the consequences of extending the time coordinate through the singularity for the physics of matter and radiation occupying just one side. Mostly this involves investigation of the relationship between the metric with line element ds{sup 2} a{sup 2}(t)(dt{sup 2}-dx{sup 2}) and time reversal symmetry within electrodynamics. It turns out compatibility between these two is possible only if there is a singular physical event at the time of the singularity or if the topology is not trivial. In both cases the singularity takes on the appearance of a time-like mirror. We are able to demonstrate a relationship between the broken time symmetry in electrodynamics characterized by retarded radiation and radiation reaction and the absolute conformal time relative to the time of the singularity, i.e. between the Electromagnetic and Cosmological arrows of time. It is determined that the Wheeler-Feynman reasoning but with the future absorber replaced by the Cosmological mirror leads to a conflict with observation unless matter is strongly bound electromagnetically to the environment.

  11. Evaluation of the management of Hr-HPV+/PapTest- women: results at 1-year recall

    PubMed Central

    Chiappetta, Caterina; Puggioni, Chiara; Lendaro, Eugenio; Cacciotti, Jessica; Zaralli, Roberto; Migliore, Giovanna; Bellardini, Paola; Petrozza, Vincenzo; Della Rocca, Carlo; Di Cristofano, Claudio

    2015-01-01

    With cervical cancer screening the choice of 1-year as a period of follow-up in positive high-risk HPV women without cytological lesions is still under discussion. We evaluated the management of these women and the role of HPV genotyping test. We did a cervical cancer screening study of women aged 35-64 with primary high-risk HPV test. Women positive for high-risk HPV with negative cytology were followed-up after 1 year. In this study we selected women with high-risk HPV+/PapTest- resulted high-risk HPV+ at recall and performed the PapTest and HPV genotyping test. The detection rate of squamous high grade (CIN2+) relative to the total screened cohort was 2.1‰, and it was 0.2‰ at the 1-year recall. The colposcopy performed in women referred at the 1-year recall accounted for 48.8% of the total (baseline + 1-year recall), and 84.3% of these women had no cytological lesions. The most frequent hr-HPV genotype detected was HPV16 and 66.7% of co-infections were due to HPV16 and HPV18. 54.5% of women presented a persistent infection at 1-year recall with the same HPV subtype, 50% of persistent infections was due to HPV16 and 16.7% of these were determined to be CIN2+ histological lesions. Our data show that it may be useful to extend the period of follow-up for women hr-HPV+/PapTest- so as to reduce the number of unnecessary colposcopies due to the transitory infections and that the genotyping test could help to identify the persistent infections in which HPV16 is involved. PMID:26884886

  12. First experiences with the direct anterior approach in lateral decubitus position: learning curve and 1 year complication rate.

    PubMed

    Melman, Wietse P R; Mollen, Bas P; Kollen, Boudewijn J; Verheyen, Cees C P M

    2015-01-01

    The direct anterior approach (DAA) in supine position for hip arthroplasty has been reported to suffer from high complication rates initially. The DAA with the patient in lateral decubitus position is believed to provide better visibility and especially femoral accessibility with potential fewer complications.The first cohort of total hip prostheses, which were implanted by a single surgeon using DAA in lateral decubitus position more than 1 year ago, was analysed retrospectively.In total 182 hip prostheses (172 patients) were analysed. Three consecutive time periods based on equal number of surgical procedures were compared. The technical complication rate and operating time improved significantly between the 3 consecutive groups. The 1 year infection rate was 0.5% and survival rate of 98.9%.This is the first series of patients that were subjected to a hip replacement based on the direct anterior approach in a lateral decubitus position in which decreasing complication rates suggest the presence of a learning curve in surgeons conducting this type of surgery. Initial complication rate was high but decreased significantly in time and was acceptable certainly in the third group of our cohort. An unacceptable complication rate with the straight uncemented stem forced us to discontinue this configuration after only 7 surgical procedures. Complication, infection and revision rates were acceptable for the all cemented hip replacements using a curved anatomical stem. PMID:25684251

  13. Trajectories of Depressive Symptomatology in Rural Memory Clinic Patients between Baseline Diagnosis and 1-Year Follow-Up

    PubMed Central

    Kosteniuk, Julie G.; Morgan, Debra G.; O'Connell, Megan E.; Kirk, Andrew; Crossley, Margaret; Stewart, Norma J.; Karunanayake, Chandima P.

    2016-01-01

    Background/Aims To investigate the prevalence and trajectories of depressive symptomatology at 1-year follow-up, and the severity of depressive symptoms, by dementia diagnostic group, as well as to determine the predictors of depressive symptomatology at 1-year follow-up. Methods In rural and remote patients of an interdisciplinary memory clinic between 2004 and 2014, 144 patients diagnosed with no cognitive impairment (NCI), mild cognitive impairment, dementia due to Alzheimer's disease (AD), or non-AD dementia completed the Center for Epidemiologic Studies of Depression Scale to assess depressive symptomatology at both time points. Results Among patients with data at both time points, persistence of depressive symptomatology at follow-up occurred in 22.2%, remission in 17.4%, incidence in 13.2%, and absence in 47.2%. The prevalence of depressive symptomatology at baseline and persistence at follow-up were significantly greater in the NCI group than in the other diagnostic groups, but there were no differences in severity. Depressive symptomatology at follow-up was independently associated with depressive symptomatology, lower independence in activities of daily living, and lower self-rating of memory at baseline, as well as with decreased independence in activities of daily living between time points. Conclusion Future studies should further examine short-term postdiagnostic trajectories in depressive symptomatology in multiple dementia diagnostic groups to inform prognoses and treatment decisions. PMID:27350776

  14. A Horizon Scan of Global Conservation Issues for 2016.

    PubMed

    Sutherland, William J; Broad, Steven; Caine, Jacqueline; Clout, Mick; Dicks, Lynn V; Doran, Helen; Entwistle, Abigail C; Fleishman, Erica; Gibbons, David W; Keim, Brandon; LeAnstey, Becky; Lickorish, Fiona A; Markillie, Paul; Monk, Kathryn A; Mortimer, Diana; Ockendon, Nancy; Pearce-Higgins, James W; Peck, Lloyd S; Pretty, Jules; Rockström, Johan; Spalding, Mark D; Tonneijck, Femke H; Wintle, Bonnie C; Wright, Katherine E

    2016-01-01

    This paper presents the results of our seventh annual horizon scan, in which we aimed to identify issues that could have substantial effects on global biological diversity in the future, but are not currently widely well known or understood within the conservation community. Fifteen issues were identified by a team that included researchers, practitioners, professional horizon scanners, and journalists. The topics include use of managed bees as transporters of biological control agents, artificial superintelligence, electric pulse trawling, testosterone in the aquatic environment, building artificial oceanic islands, and the incorporation of ecological civilization principles into government policies in China. PMID:26688445

  15. Near-horizon solution for Dvali-Gabadadze-Porrati perturbations

    SciTech Connect

    Sawicki, Ignacy; Song, Yong-Seon; Hu, Wayne

    2007-03-15

    We develop a scaling ansatz for the master equation in Dvali, Gabadadze, Porrati cosmologies, which allows us to solve the equations of motion for perturbations off the brane during periods when the on-brane evolution is scale free. This allows us to understand the behavior of the gravitational potentials outside the horizon at high redshifts and close to the horizon today. We confirm that the results of Koyama and Maartens are valid at scales relevant for observations such as galaxy-ISW correlations. At larger scales, there is an additional suppression of the potential which reduces the growth rate even further and would strengthen the integrated Sachs-Wolf effect.

  16. Earth, Meet Pluto: The New Horizons Education and Communications Partnership

    NASA Astrophysics Data System (ADS)

    Buckley, M.

    2015-12-01

    The unique partnership between the NASA New Horizons education/communications and public affairs programs tapped into the excitement of visiting an unexplored planet in a new region of the solar system - resulting in unprecedented public participation in and coverage of a planetary mission. With a range of hands-on learning experiences, Web materials and online , the program provided opportunities for students, educators, museums, science centers, the media, Web surfers and other members of the public to ride along on the first mission to Pluto and the Kuiper Belt. The programs leveraged resources, materials and expertise to address a wide range of traditional and nontraditional audiences while providing consistent messages and information on this historic NASA endeavor. The E/C program included a variety of formal lesson plans and learning materials — based on New Horizons science and engineering goals, and aligned with National Research Council's National Science Education Standards — that continue to help students in grades K-12 learn more about science, technology, engineering and mathematics. College students designed and built an actual flight instrument on New Horizons and held internships with the spacecraft integration and test team. New Horizons E/C programs went well beyond the classroom, from a chance for people to send their names to Pluto on board the New Horizons spacecraft before launch, to opportunities for the public to access milestone events and the first-ever close-up views of Pluto in places such as museums, science centers and libraries, TV and the Web — as well as thousands who attended interactive "Plutopalooza" road shows across the country. Teamed with E/C was the public affairs strategy to communicate New Horizons news and messages to media, mission stakeholders, the scientific community and the public. These messages include various aspects of New Horizons, including the progress of the mission and key milestones and achievements

  17. A horizon scan of global conservation issues for 2014.

    PubMed

    Sutherland, William J; Aveling, Rosalind; Brooks, Thomas M; Clout, Mick; Dicks, Lynn V; Fellman, Liz; Fleishman, Erica; Gibbons, David W; Keim, Brandon; Lickorish, Fiona; Monk, Kathryn A; Mortimer, Diana; Peck, Lloyd S; Pretty, Jules; Rockström, Johan; Rodríguez, Jon Paul; Smith, Rebecca K; Spalding, Mark D; Tonneijck, Femke H; Watkinson, Andrew R

    2014-01-01

    This paper presents the output of our fifth annual horizon-scanning exercise, which aims to identify topics that increasingly may affect conservation of biological diversity, but have yet to be widely considered. A team of professional horizon scanners, researchers, practitioners, and a journalist identified 15 topics which were identified via an iterative, Delphi-like process. The 15 topics include a carbon market induced financial crash, rapid geographic expansion of macroalgal cultivation, genetic control of invasive species, probiotic therapy for amphibians, and an emerging snake fungal disease. PMID:24332318

  18. A horizon scan of global conservation issues for 2014

    PubMed Central

    Sutherland, William J.; Aveling, Rosalind; Brooks, Thomas M.; Clout, Mick; Dicks, Lynn V.; Fellman, Liz; Fleishman, Erica; Gibbons, David W.; Keim, Brandon; Lickorish, Fiona; Monk, Kathryn A.; Mortimer, Diana; Peck, Lloyd S.; Pretty, Jules; Rockström, Johan; Rodríguez, Jon Paul; Smith, Rebecca K.; Spalding, Mark D.; Tonneijck, Femke H.; Watkinson, Andrew R.

    2014-01-01

    This paper presents the output of our fifth annual horizon-scanning exercise, which aims to identify topics that increasingly may affect conservation of biological diversity, but have yet to be widely considered. A team of professional horizon scanners, researchers, practitioners, and a journalist identified 15 topics which were identified via an iterative, Delphi-like process. The 15 topics include a carbon market induced financial crash, rapid geographic expansion of macroalgal cultivation, genetic control of invasive species, probiotic therapy for amphibians, and an emerging snake fungal disease. PMID:24332318

  19. Robust Consumption-Investment Problem on Infinite Horizon

    SciTech Connect

    Zawisza, Dariusz

    2015-12-15

    In our paper we consider an infinite horizon consumption-investment problem under a model misspecification in a general stochastic factor model. We formulate the problem as a stochastic game and finally characterize the saddle point and the value function of that game using an ODE of semilinear type, for which we provide a proof of an existence and uniqueness theorem for its solution. Such equation is interested on its own right, since it generalizes many other equations arising in various infinite horizon optimization problems.

  20. The New Horizons Mission to Pluto and Flyby of Jupiter

    NASA Technical Reports Server (NTRS)

    Stern, Alan; Weaver, Hal; Young, Leslie; Bagenal, Fran; Binzel, Richard; Buratti, Bonnie; Cheng, andy; Cruikshank, Dale; Gladstone, Randy; Grundy, Will; Hinson, David; Horanyi, Mihaly; Jennings, Don; Linscott, Ivan; McComas, Dave; McKinnon, William; McNutt, Ralph; Moore, Jeffrey; Murchie, Scott; Olkin, Cathy; Porco, Carolyn; Reitsema, Harold; Reuter, Dennis; Slater, Dave; Spencer, John

    2008-01-01

    New Horizons (NH) is NASA's mission to provide the first in situ reconnaissance of Pluto and its moons Charon, Nix, and Hydra. The NH spacecraft will reach Pluto in July 2015 and will then, if approved for an extended mission phase, continue on to a flyby encounter with one or more Kuiper belt objects (KBOs). NH was launched on 19 January 2006 and received a gravity assist during a flyby encounter with Jupiter (with closest approach at -32 RJ on 28 February 2007) that reduced its flight time to Pluto by 3 years. During the Jupiter flyby, NH collected a trove of multi-wavelength imaging and fields-and-particles measurements. Among the many science results at Jupiter were a detection of planet-wide mesoscale waves, eruptions of atmospheric ammonia clouds, unprecedented views of Io's volcanic plumes and Jupiter's tenuous ring system, a first close-up of the Little Red Spot (LRS), first sightings of polar lightning, and a trip down the tail of the magnetosphere. In 2015, NH will conduct a seven-month investigation of the Pluto system culminating in a closest approach some 12,500 km from Pluto's surface. Planning is presently underway for the Pluto encounter with special emphasis on longidentified science goals of studying the terrain, geology, and composition of the surfaces of Pluto and Charon, examining the composition and structure of Pluto's atmosphere, searching for an atmosphere on Charon, and characterizing Pluto's ionosphere and solar wind interaction. Detailed inspections will also be performed of the newly discovered satellites Nix and Hydra. Additionally, NH will characterize energetic particles in Pluto's environment, refine the bulk properties of Pluto and Charon, and search for additional satellites and rings.

  1. A Review of Seafood Safety after the Deepwater Horizon Blowout

    PubMed Central

    Doke, Dzigbodi; Tipre, Meghan; Leader, Mark; Fitzgerald, Timothy

    2011-01-01

    Background: The Deepwater Horizon (DH) blowout resulted in fisheries closings across the Gulf of Mexico. Federal agencies, in collaboration with impacted Gulf states, developed a protocol to determine when it is safe to reopen fisheries based on sensory and chemical analyses of seafood. All federal waters have been reopened, yet concerns have been raised regarding the robustness of the protocol to identify all potential harmful exposures and protect the most sensitive populations. Objectives: We aimed to assess this protocol based on comparisons with previous oil spills, published testing results, and current knowledge regarding chemicals released during the DH oil spill. Methods: We performed a comprehensive review of relevant scientific journal articles and government documents concerning seafood contamination and oil spills and consulted with academic and government experts. Results: Protocols to evaluate seafood safety before reopening fisheries have relied on risk assessment of health impacts from polycyclic aromatic hydrocarbon (PAH) exposures, but metal contamination may also be a concern. Assumptions used to determine levels of concern (LOCs) after oil spills have not been consistent across risk assessments performed after oil spills. Chemical testing results after the DH oil spill suggest PAH levels are at or below levels reported after previous oil spills, and well below LOCs, even when more conservative parameters are used to estimate risk. Conclusions: We recommend use of a range of plausible risk parameters to set bounds around LOCs, comparisons of post-spill measurements with baseline levels, and the development and implementation of long-term monitoring strategies for metals as well as PAHs and dispersant components. In addition, the methods, results, and uncertainties associated with estimating seafood safety after oil spills should be communicated in a transparent and timely manner, and stakeholders should be actively involved in developing a long

  2. 1-year retention rates and performance ratings: comparing associate degree, baccalaureate, and accelerated baccalaureate degree nurses.

    PubMed

    Weathers, Suzanne M; Raleigh, Edith D Hunt

    2013-09-01

    The purpose of this study was to examine 1-year retention and managerial performance ratings of newly licensed RNs (NLRNs) according to nursing education program types (associate degree, traditional baccalaureate, and accelerated 2nd degree baccalaureate). Findings revealed retention and performance differences, suggesting the possibility of tradeoffs related to educational program type when selecting NLRNs for open positions. PMID:23958525

  3. Randomized Trial of a Gatekeeper Program for Suicide Prevention: 1-Year Impact on Secondary School Staff

    ERIC Educational Resources Information Center

    Wyman, Peter A.; Brown, C. Hendricks; Inman, Jeff; Cross, Wendi; Schmeelk-Cone, Karen; Guo, Jing; Pena, Juan B.

    2008-01-01

    Gatekeeper-training programs, designed to increase identification and referral of suicidal individuals, are widespread but largely untested. A group-based randomized trial with 32 schools examined impact of Question, Persuade, Refer (QPR) training on a stratified random sample of 249 staff with 1-year average follow-up. To test QPR impact, the…

  4. Thai Adolescent Survivors 1 Year after the 2004 Tsunami: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Tuicomepee, Arunya; Romano, John L.

    2008-01-01

    This study examined the impact of the 2004 Asian tsunami on 400 Thai adolescents 1 year after the disaster. Quantitative analyses showed that youth behavior problems were positively associated with tsunami experiences and negatively associated with positive family functioning. Tsunami exposure, school connectedness, religious beliefs and…

  5. The Stability and Structure of Career Decision-Making Profiles: A 1-Year Follow-Up

    ERIC Educational Resources Information Center

    Gati, Itamar; Levin, Nimrod

    2012-01-01

    The Career Decision-Making Profile (CDMP) questionnaire is a multidimensional measure of the way individuals make career decisions, developed as an alternative to the single, most-dominant trait approach. Using a sample of freshmen students, the 2-week reliability (N = 273) and 1-year stability (N = 182) of the CDMP was tested for each of the 12…

  6. An Analysis of 1-Year Impacts of Youth Transition Demonstration Projects

    ERIC Educational Resources Information Center

    Fraker, Thomas M.; Luecking, Richard G.; Mamun, Arif A.; Martinez, John M.; Reed, Deborah S.; Wittenburg, David C.

    2016-01-01

    This article examines the impacts of the Youth Transition Demonstration, an initiative of the Social Security Administration (SSA) to improve employment outcomes for youth with disabilities. Based on a random assignment design, the analysis uses data from a 1-year follow-up survey and SSA administrative records for 5,203 youth in six research…

  7. A rare case of peripheral T-cell lymphoma in 1-year-old child

    PubMed Central

    Kandakumar, Vignesh; Ganesan, Prasanth; Bajpai, Peush; Rajendranath, Rejiv; Tenali, Sagar; Majhi, Urmila; Sivaprakasam, Ponni

    2011-01-01

    Peripheral T-cell lymphoma (PTCL) represents approximately 12% of lymphoid neoplasms. They are even rarer in children and represent only 1% of Non-Hodgkin's lymphoma in this age group. We report a case of PTCL in a 1-year-old female child for its rarity. PMID:22563159

  8. Dialectical Behavior Therapy for Adolescents with Bipolar Disorder: A 1-Year Open Trial

    ERIC Educational Resources Information Center

    Goldstein, Tina R.; Axelson, David A.; Birmaher, Boris; Brent, David A.

    2007-01-01

    Objective: To describe an adapted version of dialectical behavior therapy for adolescents with bipolar disorder. Method: The dialectical behavior therapy intervention is delivered over 1 year and consists of two modalities: family skills training (conducted with individual family units) and individual therapy. The acute treatment period (6 months)…

  9. Levels of Phonological Awareness in Korean and English: A 1-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Cho, Jeung-Ryeul; McBride-Chang, Catherine

    2005-01-01

    The present study examined associations of levels of phonological awareness to word recognition in Korean and English in a 1-year longitudinal study of 91 children from Masan, Korea. With performances on tasks of speeded naming, vocabulary, and Korean Hangul in 2nd grade statistically controlled, only Korean syllable deletion predicted unique…

  10. Verbal Labels Modulate Perceptual Object Processing in 1-Year-Old Children

    ERIC Educational Resources Information Center

    Gliga, Teodora; Volein, Agnes; Csibra, Gergely

    2010-01-01

    Whether verbal labels help infants visually process and categorize objects is a contentious issue. Using electroencephalography, we investigated whether possessing familiar or novel labels for objects directly enhances 1-year-old children's neural processes underlying the perception of those objects. We found enhanced gamma-band (20-60 Hz)…

  11. Latent Classes of Adolescent Posttraumatic Stress Disorder Predict Functioning and Disorder after 1 Year

    ERIC Educational Resources Information Center

    Ayer, Lynsay; Danielson, Carla Kmett; Amstadter, Ananda B.; Ruggiero, Ken; Saunders, Ben; Kilpatrick, Dean

    2011-01-01

    Objective: To identify latent classes of posttraumatic stress disorder (PTSD) symptoms in a national sample of adolescents, and to test their associations with PTSD and functional impairment 1 year later. Method: A total of 1,119 trauma-exposed youth aged 12 through 17 years (mean = 14.99 years, 51% female and 49% male) participating in the…

  12. Predicting 1-Year Mortality Rate for Patients Admitted With an Acute Exacerbation of Chronic Obstructive Pulmonary Disease to an Intensive Care Unit: An Opportunity for Palliative Care

    PubMed Central

    Batzlaff, Cassandra M.; Karpman, Craig; Afessa, Bekele; Benzo, Roberto P.

    2015-01-01

    The objective of this study was to develop a model to aid clinicians in better predicting 1-year mortality rate for patients with an acute exacerbation of chronic obstructive pulmonary disease admitted to the medical intensive care unit (ICU) with the goal of earlier initiation of palliative care and end-of-life communications in this patient population. This retrospective cohort study included patients from a medical ICU from April 1, 1995, to November 30, 2009. Data collected from the Acute Physiology and Chronic Health Evaluation III database included demographic characteristics; severity of illness scores; noninvasive and invasive mechanical ventilation time; ICU and hospital length of stay; and ICU, hospital, and 1-year mortality. Statistically significant univariate variables for 1-year mortality were entered into a multivariate model, and the independent variables were used to generate a scoring system to predict 1-year mortality rate. At 1-year follow-up, 295 of 591 patients died (50%). Age and hospital length of stay were identified as independent determinants of mortality at 1 year by using multivariate analysis, and the predictive model developed had an area under the operating curve of 0.68. Bootstrap analysis with 1000 iterations validated the model, age, and hospital length of stay, entered the model 100% of the time (area under the operating curve=0.687; 95% CI, 0.686–0.688). A simple model using age and hospital length of stay may be informative for providers willing to identify patients with chronic obstructive pulmonary disease with high 1-year mortality rate who may benefit from end-of-life communications and from palliative care. PMID:24656805

  13. Endoscopic sleeve gastroplasty with 1-year follow-up: factors predictive of success

    PubMed Central

    Lopez-Nava, G.; Galvao, M.; Bautista-Castaño, I.; Fernandez-Corbelle, J. P.; Trell, M.

    2016-01-01

    Background and study aims: Bariatric endoscopy has emerged as an aid in the nonsurgical treatment of obesity. The objective of this study is to critically provide the results and follow-up of endoscopic sleeve gastroplasty 1 year after the procedure. Patients and methods: Prospective single-center follow-up study of 25 patients (5 men, 20 women) who underwent flexible endoscopic suturing for endoluminal gastric volume reduction. A multidisciplinary team provided post-procedure care. Patient outcomes were recorded at 1 year after the procedure. Linear regression analysis was done to evaluate the variables associated with best results at 1 year of follow-up. Results: Mean body mass index (BMI) was 38.5 ± 4.6 kg/m2 (range 30 – 47) and mean age 44.5 ± 8.2 years (range 29 – 60). At 1 year, 22 patients continued with the follow-up (2 dropped out at 6 months and 1 at 3 months). There were no major intra-procedural, early, or delayed adverse events. Mean BMI loss was 7.3 ± 4.2 kg/m2, and mean percentage of total body weight loss was 18.7 ± 10.7 at 1 year. In the linear regression analysis, adjusted by initial BMI, variables associated with %TBWL involved the frequency of nutritional (β = 0.563, P = 0.014) and psychological contacts (β = 0.727, P = 0.025). The number of nutritional and psychological contacts were predictive of good weight loss results. Conclusions: Endoscopic sleeve gastroplasty is a feasible, reproducible, and effective procedure to treat obesity. Nutritional and psychological interaction are predictive of success. PMID:26878054

  14. Subclinical Rejection Phenotypes at 1 Year Post-Transplant and Outcome of Kidney Allografts.

    PubMed

    Loupy, Alexandre; Vernerey, Dewi; Tinel, Claire; Aubert, Olivier; Duong van Huyen, Jean-Paul; Rabant, Marion; Verine, Jérôme; Nochy, Dominique; Empana, Jean-Philippe; Martinez, Frank; Glotz, Denis; Jouven, Xavier; Legendre, Christophe; Lefaucheur, Carmen

    2015-07-01

    Kidney allograft rejection can occur in clinically stable patients, but long-term significance is unknown. We determined whether early recognition of subclinical rejection has long-term consequences for kidney allograft survival in an observational prospective cohort study of 1307 consecutive nonselected patients who underwent ABO-compatible, complement-dependent cytotoxicity-negative crossmatch kidney transplantation in Paris (2000-2010). Participants underwent prospective screening biopsies at 1 year post-transplant, with concurrent evaluations of graft complement deposition and circulating anti-HLA antibodies. The main analysis included 1001 patients. Three distinct groups of patients were identified at the 1-year screening: 727 (73%) patients without rejection, 132 (13%) patients with subclinical T cell-mediated rejection (TCMR), and 142 (14%) patients with subclinical antibody-mediated rejection (ABMR). Patients with subclinical ABMR had the poorest graft survival at 8 years post-transplant (56%) compared with subclinical TCMR (88%) and nonrejection (90%) groups (P<0.001). In a multivariate Cox model, subclinical ABMR at 1 year was independently associated with a 3.5-fold increase in graft loss (95% confidence interval, 2.1 to 5.7) along with eGFR and proteinuria (P<0.001). Subclinical ABMR was associated with more rapid progression to transplant glomerulopathy. Of patients with subclinical TCMR at 1 year, only those who further developed de novo donor-specific antibodies and transplant glomerulopathy showed higher risk of graft loss compared with patients without rejection. Our findings suggest that subclinical TCMR and subclinical ABMR have distinct effects on long-term graft loss. Subclinical ABMR detected at the 1-year screening biopsy carries a prognostic value independent of initial donor-specific antibody status, previous immunologic events, current eGFR, and proteinuria. PMID:25556173

  15. Higher Horizons: An Evaluation of an Expanded Team Program.

    ERIC Educational Resources Information Center

    Hartford Public Schools, CT.

    The original Higher Horizons Program or HH 100, was established in 1965 as a ninth grade compensatory model which could be used to demonstrate that some of the more salient ravages of educational deprivation could be corrected effectively, and at the high school level. So as to demonstrate that secondary school compensatory education could…

  16. Knowledge Concerning the Mathematical Horizon: A Close View

    ERIC Educational Resources Information Center

    Guberman, Raisa; Gorev, Dvora

    2015-01-01

    The main objective of this study is to identify components of teachers' mathematical knowledge for teaching, associated with the knowledge of mathematical horizon (KMH) in order to describe this type of knowledge from the viewpoint of elementary school mathematics teachers. The research population of this study consisted of 118 elementary school…

  17. Solution to the cosmological horizon problem proposed by Zee

    SciTech Connect

    Pollock, M.D.

    1981-08-15

    Applying a theory of gravity with broken symmetry, Zee has suggested a solution to the cosmological horizon problem. His idea has been criticized on two independent grounds by Linde and by Sato. In this paper, we suggest answers to both these criticisms.

  18. New Horizons: An Empowerment Program for Egyptian Adolescent Girls.

    ERIC Educational Resources Information Center

    Swanson, Julie Hanson

    New Horizons is a nonschool program that demystifies and communicates essential information on basic life skills and reproductive health to Egyptian girls and young women aged 9-20. The program consists of 100 hour-long sessions, each including an introduction to a specific topic, review of group knowledge level, discussion around key points…

  19. Community Colleges Broadening Horizons through Service Learning, 2006-2009

    ERIC Educational Resources Information Center

    Robinson, Gail

    2007-01-01

    This brief introduces "Community Colleges Broadening Horizons through Service Learning," the American Association of Community Colleges' (AACC's) fifth national Learn and Serve America grant project and describes its grantee college programs. The goals of this grant project are to build on established foundations to integrate service learning…

  20. Breaking an Abelian gauge symmetry near a black hole horizon

    SciTech Connect

    Gubser, Steven S.

    2008-09-15

    I argue that coupling the Abelian Higgs model to gravity plus a negative cosmological constant leads to black holes which spontaneously break the gauge invariance via a charged scalar condensate slightly outside their horizon. This suggests that black holes can superconduct.

  1. Colorful Horizons with Charge in Anti-de Sitter Space

    SciTech Connect

    Gubser, Steven S.

    2008-11-07

    An Abelian gauge symmetry can be spontaneously broken near a black hole horizon in anti-de Sitter space using a condensate of non-Abelian gauge fields. A second order phase transition is shown to separate Reissner-Nordstroem-anti-de Sitter solutions from a family of symmetry-breaking solutions which preserve a diagonal combination of gauge invariance and spatial rotational invariance.

  2. New Horizons for Learning: An Interview with Dee Dickinson

    ERIC Educational Resources Information Center

    Windham, Scott; Dickinson, Dee

    2005-01-01

    This article presents an interview with Dee Dickinson, founder and chief learning officer of New Horizons for Learning, a nonprofit international education network whose mission is to identify, communicate, and help implement effective teaching and learning strategies. Founded in 1980 and now operating largely through its Web site, New Horizons…

  3. Apparent horizons in D-dimensional Robinson-Trautman spacetime

    SciTech Connect

    Svitek, Otakar

    2009-05-01

    We derive the higher dimensional generalization of Penrose-Tod equation describing apparent horizons in Robinson-Trautman spacetimes. New results concerning the existence and uniqueness of its solutions in four dimensions are proven. Namely, previous results of Tod [1] are generalized to nonvanishing cosmological constant.

  4. 7. PHOTOGRAPHIC COPY OF ORIGINAL CONSTRUCTION DRAWING, DATED 1918, HORIZONAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. PHOTOGRAPHIC COPY OF ORIGINAL CONSTRUCTION DRAWING, DATED 1918, HORIZONAL SLIDING WINDOW DETAIL, WAR DEPARTMENT, MANUAL OF THE CONSTRUCTION DIVISION OF THE ARMY, WAR EMERGENCY CONSTRUCTION, SECTION C, ENGINEERING DIVISION, PLATE 5, CONSOLIDATED SUPPLY COMPANY PRINTERS, WASHINGTON - Fort Bliss, 7th Cavalry Buildings, U.S. Army Air Defence Artillery Center & Fort Bliss, El Paso, El Paso County, TX

  5. SOLUBLE ALUMINUM IN ACIDIFIED ORGANIC HORIZONS OF FOREST SOILS

    EPA Science Inventory

    Concentrations of labile and total Al in soil extracts were measured as a function of equilibrium solution pH in six forest soil organic horizons acidified with HNO, (0-20 cmol H+.kg-1) under controlled conditions of ionic strength (0.05 M NaNO3), temperature (23 C), and solution...

  6. The high water-holding capacity of petrocalcic horizons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Petrocalcic soil horizons occur in most arid and semi-arid ecosystems around the world, often within the plant rooting zone. Little is known, however, about the water holding characteristic of soils indurated with calcium carbonate. We conducted a replicated experiment to define the soil-water relea...

  7. Star/horizon simulator used to test space guidance system

    NASA Technical Reports Server (NTRS)

    Schmidt, W. C.

    1967-01-01

    Star/horizon simulator is used for alignment and optical plus photoelectric tests of the sextant for the Apollo guidance and navigation system optical unit assembly. The unit is basically a refractive collimator with a two inch objective lens system and a twenty-four inch focal length.

  8. Black Hole Physics with the Event Horizon Telescope

    NASA Astrophysics Data System (ADS)

    Ozel, Feryal

    2016-01-01

    The Event Horizon Telescope is an experiment that is being performed on a large and ever-increasing array of radio telescopes that span the Earth from Hawaii to Chile and from the South Pole to Arizona. When data will be taken with the full array, it will image the event horizons of the supermassive black hole at the center of our Galaxy, Sagittarius A*, and the black hole at the center of M87, with an unprecedented 10 microarcssecond resolution. This will allow us to take the first ever pictures of black holes at 1.3 and 0.85 mm wavelengths and look for the shadow that is a direct evidence for a black hole predicted by the theory of General Relativity. In addition, the Event Horizon Telescope will also enable us to study the process by which black holes accrete matter and grow in mass. I will discuss the theoretical developments in simulating the properties of the black hole accretion flows and their expected images using state-of-the-art algorithms and high performance computing. Interpreting the upcoming observations within this theoretical framework will open new horizons in black hole astrophysics.

  9. Ecological Impacts of the Deepwater Horizon Oil Spill (Bogota, Columbia)

    EPA Science Inventory

    The Deepwater Horizon oil spill (DWH) was the largest environmental disaster and response effort in US History, with nearly 800 million liters spilled. Vast areas of the Gulf of Mexico were contaminated with oil, including deep ocean communities, protected species, over 1600 km o...

  10. Survey of New Horizons International Music Association Musicians

    ERIC Educational Resources Information Center

    Coffman, Don

    2009-01-01

    This study analysed survey responses from 1652 New Horizons International Music Association (NHIMA) musicians in the United States and Canada to better understand older adults' experiences in making music. The purpose of this study was threefold: (a) ascertain the extent of NHIMA musicians' musical backgrounds and their current involvement in…

  11. Ecological impacts of the Deepwater Horizon oil spill

    EPA Science Inventory

    The Deepwater Horizon oil spill (DWH) was the largest environmental disaster and response effort in United States history, with nearly 800 million liters of crude oil spilled. Vast areas of the Gulf of Mexico were contaminated with oil, including deep ocean communities and over 1...

  12. Ecological Impacts during the Deepwater Horizon Oil Spill

    EPA Science Inventory

    The Deepwater Horizon (DWH) oil spill was the largest spill and response effort in United States history. Nearly 800 million L of oil was spilled in the Gulf of Mexico, and nearly 7 million L of chemical dispersants were applied in at the ocean surface and subsea1. The DWH spill ...

  13. How Big Is the Earth? A Calculation beyond Your Horizon

    ERIC Educational Resources Information Center

    Kibble, Bob

    2011-01-01

    A consequence of the curvature of the Earth is that distant ships apparently disappear over the horizon. This article shows how you can use a simple photograph to help students obtain a reasonable estimate of the size of the Earth using little more than the mathematics of Pythagoras. (Contains 5 figures.)

  14. The Horizon Project Call to Scholarship: 2007-8

    ERIC Educational Resources Information Center

    New Media Consortium, 2007

    2007-01-01

    With the release of the fourth edition in the annual "Horizon Report, the New Media Consortium (NMC) has undertaken a concerted, international effort to describe a research agenda and call to scholarship based on the six practices and technologies featured in the report. The community was invited to participate in this process, contribute to the…

  15. CFT/gravity correspondence on the isolated horizon

    NASA Astrophysics Data System (ADS)

    Ghosh, Amit; Pranzetti, Daniele

    2014-12-01

    A quantum isolated horizon can be modelled by an SU (2) Chern-Simons theory on a punctured 2-sphere. We show how a local 2-dimensional conformal symmetry arises at each puncture inducing an infinite set of new observables localised at the horizon which satisfy a Kac-Moody algebra. By means of the isolated horizon boundary conditions, we represent the gravitational flux degrees of freedom in terms of the zero modes of the Kac-Moody algebra defined on the boundary of a punctured disk. In this way, our construction encodes a precise notion of CFT/gravity correspondence. The higher modes in the algebra represent new nongeometric charges which can be represented in terms of free matter field degrees of freedom. When computing the CFT partition function of the system, these new states induce an extra degeneracy factor, representing the density of horizon states at a given energy level, which reproduces the Bekenstein's holographic bound for an imaginary Immirzi parameter. This allows us to recover the Bekenstein-Hawking entropy formula without the large quantum gravity corrections associated with the number of punctures.

  16. Rethinking Classroom Management: A New Perspective, a New Horizon

    ERIC Educational Resources Information Center

    Toprakci, Erdal

    2012-01-01

    The purpose of this study is to suggest a new perspective and a new horizon by analyzing the concept of classroom management in the literature of traditional classroom management from a scientific and dictionary view. It may be said that there are serious problems regarding the settlement of the meaning of "classroom management" in the educational…

  17. Physics from the News: The Deepwater Horizon Disaster

    NASA Astrophysics Data System (ADS)

    Bartlett, Albert

    2010-10-01

    A surprising (at least to me) phenomenon from hydrostatics may have played a role in initiating the blowout and fire (April 20, 2010) that burned for two days before sinking the drilling ship the Deepwater Horizon, resulting in a large and environmentally destructive oil spill in the Gulf of Mexico.

  18. Ecological Impacts During the Deepwater Horizon Oil Spill Response

    EPA Science Inventory

    The Deepwater Horizon (DWH) oil spill was the largest environmental disaster and response effort in U.S. history, with nearly 800 million liters of crude oil spilled. Vast areas of the Gulf of Mexico were contaminated with oil, including deep-ocean communities and over 1,600 kilo...

  19. New Horizons in Education, No. 39.

    ERIC Educational Resources Information Center

    Ho, Kwok Keung, Ed.

    1998-01-01

    The annual issue of the journal of the Hong Kong Teachers Association includes these articles: "The Time Management Issue of Tertiary Students: An Investigation of Tuition Conductors in Singapore" (Tai Chee Wong, Jessie Yuk Yong Wong); "The Analysis of the Phenomena of Parkinson in Course of School Management" (Ying Xiu Yang) (in Chinese); "Zero…

  20. Volcanic resurfacing of Io between Galileo and New Horizons Observations

    NASA Astrophysics Data System (ADS)

    Coman, E.; Phillips, C. B.

    2011-12-01

    Io is the most geologically active object in our solar system. Due to its tumultuous volcanism, determining Io's resurfacing rate will allow better characterization of the subsurface structure, thermal state, and history of tidal heating of this small moon. Numerous active volcanic centers were documented during the Galileo mission in the late 1990's and early 2000's, and the opportunity to discover more of these centers was presented with the flyby of New Horizons in 2007. Previous authors (i.e. Spencer et al. 2007) have compared Galileo SSI and New Horizons LORRI images with similar viewing geometry, and have found multiple new potential features such as dark lava flows and bright plume deposits emplaced between the two flybys. The purpose of this study was to measure the extent of these changes on Io. Because an ISIS camera model does not yet exist for LORRI, a direct ratio image for comparison with the Galileo SSI images could not be created. By changing the stretch of the Galileo SSI images to match those of New Horizons as closely as possible, we were able to create a rough ratio image for the active center locations. We used these ratio images to measure the areal extent of the new deposits, taking careful precautions to measure more changes in shape than brightness, as brightness variations can be caused by certain surface materials being viewed at different phase angles between the Galileo and New Horizons flybys. This presentation will report our measurement findings. We then are able to use our measurements of the total area covered by new volcanic features to make estimates of the resurfacing rate of Io. Spencer, J.R. et al. (2007), Io Volcanism Seen by New Horizons: A Major Eruption of the Tvashtar Volcano, Science, 318, 240, DOI:10.1126/science.1147621.

  1. BDNF and NGF Signalling in Early Phases of Psychosis: Relationship With Inflammation and Response to Antipsychotics After 1 Year.

    PubMed

    Martinez-Cengotitabengoa, M; MacDowell, K S; Alberich, S; Diaz, F J; Garcia-Bueno, B; Rodriguez-Jimenez, R; Bioque, M; Berrocoso, E; Parellada, M; Lobo, A; Saiz, P A; Matute, C; Bernardo, M; Gonzalez-Pinto, A; Leza, J C

    2016-01-01

    Previous studies have indicated systemic deregulation of the proinflammatory or anti-inflammatory balance in individuals with first-episode psychosis (FEP) that persists 12 months later. To identify potential risk/protective factors and associations with symptom severity, we assessed possible changes in plasma levels of neurotrophins (brain-derived neurotrophic factor [BDNF] and nerve growth factor [NGF]) and their receptors in peripheral blood mononuclear cells (PBMCs). Expression of the 2 forms of BDNF receptors (active TrkB-FL and inactiveTrkB-T1) in PBMCs of FEP patients changed over time, TrkB-FL expression increasing by 1 year after diagnosis, while TrkB-T1 expression decreased. The TrkB-FL/TrkB-T1 ratio (hereafter FL/T1 ratio) increased during follow-up in the nonaffective psychosis group only, suggesting different underlying pathophysiological mechanisms in subgroups of FEP patients. Further, the expression of the main NGF receptor, TrkA, generally increased in patients at follow-up. After adjusting for potential confounders, baseline levels of inducible isoforms of nitric oxide synthase, cyclooxygenase, and nuclear transcription factor were significantly associated with the FL/T1 ratio, suggesting that more inflammation is associated with higher values of this ratio. Interestingly, the FL/T1 ratio might have a role as a predictor of functioning, a regression model of functioning at 1 year suggesting that the effect of the FL/T1 ratio at baseline on functioning at 1 year depended on whether patients were treated with antipsychotics. These findings may have translational relevance; specifically, it might be useful to assess the expression of TrkB receptor isoforms before initiating antipsychotic treatment in FEPs. PMID:26130821

  2. BDNF and NGF Signalling in Early Phases of Psychosis: Relationship With Inflammation and Response to Antipsychotics After 1 Year

    PubMed Central

    Martinez-Cengotitabengoa, M.; MacDowell, K.S.; Alberich, S.; Diaz, F.J.; Garcia-Bueno, B.; Rodriguez-Jimenez, R.; Bioque, M.; Berrocoso, E.; Parellada, M.; Lobo, A.; Saiz, P.A.; Matute, C.; Bernardo, M.; Gonzalez-Pinto, A.; Leza, J.C.

    2016-01-01

    Previous studies have indicated systemic deregulation of the proinflammatory or anti-inflammatory balance in individuals with first-episode psychosis (FEP) that persists 12 months later. To identify potential risk/protective factors and associations with symptom severity, we assessed possible changes in plasma levels of neurotrophins (brain-derived neurotrophic factor [BDNF] and nerve growth factor [NGF]) and their receptors in peripheral blood mononuclear cells (PBMCs). Expression of the 2 forms of BDNF receptors (active TrkB-FL and inactiveTrkB-T1) in PBMCs of FEP patients changed over time, TrkB-FL expression increasing by 1 year after diagnosis, while TrkB-T1 expression decreased. The TrkB-FL/TrkB-T1 ratio (hereafter FL/T1 ratio) increased during follow-up in the nonaffective psychosis group only, suggesting different underlying pathophysiological mechanisms in subgroups of FEP patients. Further, the expression of the main NGF receptor, TrkA, generally increased in patients at follow-up. After adjusting for potential confounders, baseline levels of inducible isoforms of nitric oxide synthase, cyclooxygenase, and nuclear transcription factor were significantly associated with the FL/T1 ratio, suggesting that more inflammation is associated with higher values of this ratio. Interestingly, the FL/T1 ratio might have a role as a predictor of functioning, a regression model of functioning at 1 year suggesting that the effect of the FL/T1 ratio at baseline on functioning at 1 year depended on whether patients were treated with antipsychotics. These findings may have translational relevance; specifically, it might be useful to assess the expression of TrkB receptor isoforms before initiating antipsychotic treatment in FEPs. PMID:26130821

  3. Clouds and rainbows on the HIPAA horizon.

    PubMed

    Tennant, R M

    1999-01-01

    In the planning phase for several years, the administrative simplification provisions of the Health Insurance Portability and Accountability Act of 1996 (HIPAA) finally appear ready for implementation. The Health Care Financing Administration (HCFA) expects that the major HIPAA measures will be released in late 1999. For group practices, it is expected that implementation of these provisions will be complicated and consume significant amounts of time and money. Still, the end result should justify the effort. PMID:10788078

  4. Solar Wind Observations from 10 to 30 AU Measured With The New Horizons Solar Wind Around Pluto (SWAP) Instrument

    NASA Astrophysics Data System (ADS)

    Elliott, H. A.; McComas, D. J.; Valek, P. W.; Nicolaou, G.; Bagenal, F.; Delamere, P. A.; Livadiotis, G.

    2014-12-01

    Beginning in 2012 the New Horizons mission to Pluto began collecting solar wind observations during the spacecraft hibernation greatly increasing the solar wind coverage. We have extensively analyzed both the laboratory and flight calibration measurements for the Solar Wind Around Pluto (SWAP) instrument to produce a data set of solar wind observations at times when the New Horizons spacecraft is spinning. This full data set spans from 10 to 30 AU, and the improved coverage portion spans from 20- 30 AU. Coincidently, in 2012 and 2013 the ACE, STEREO A, and STEREO B were well separated in longitude. We compare the New Horizons speeds with propagated 1 AU speed measurements, and find many of the largest scale structures persist beyond 20 AU. The New Horizons solar wind coverage between 20 and 30 AU is now extensive enough to examine the temperature-speed relationship and compare that to the relationship found in the inner heliosphere and to that in the Voyager 2 observations. Upon initial examination we also find a temperature-speed relationship that persists in the 20-30 AU distance range.

  5. Composition and structure of aggregates from compacted soil horizons in the southern steppe zone of European Russia

    NASA Astrophysics Data System (ADS)

    Sorokin, A. S.; Abrosimov, K. N.; Lebedeva, M. P.; Kust, G. S.

    2016-03-01

    The composition and structure of aggregates from different agrogenic soils in the southern steppe zone of European Russia have been studied. It is shown that the multi-level study (from the macro- to microlevel) of these horizons makes it possible to identify soil compaction caused by different elementary soil processes: solonetz-forming, vertisol-forming, and mechanical (wheel) compaction in the rainfed and irrigated soils. The understanding of the genesis of the compaction of soil horizons (natural or anthropogenic) is important for the economic evaluation of soil degradation. It should enable us to make more exact predictions of the rates of degradation processes and undertake adequate mitigation measures. The combined tomographic and micromorphological studies of aggregates of 1-2 and 3-5 mm in diameter from compacted horizons of different soils have been performed for the first time. Additional diagnostic features of negative solonetz- forming processes (low open porosity of aggregates seen on tomograms and filling of a considerable part of the intraped pores with mobile substance) and the vertisol-forming processes (large amount of fine intraaggregate pores seen on tomograms and a virtual absence of humus-clay plasma in the intraped zone)—have been identified. It is shown that the combination of microtomographic and micromorphological methods is helpful for studying the pore space of compacted horizons in cultivated soils.

  6. Early Neuropsychological Tests as Correlates of Productivity 1 Year after Traumatic Brain Injury: A Preliminary Matched Case-Control Study

    ERIC Educational Resources Information Center

    Ryu, Won Hyung A.; Cullen, Nora K.; Bayley, Mark T.

    2010-01-01

    This study explored the relative strength of five neuropsychological tests in correlating with productivity 1 year after traumatic brain injury (TBI). Six moderate-to-severe TBI patients who returned to work at 1-year post-injury were matched with six controls who were unemployed after 1 year based on age, severity of injury, and Functional…

  7. A practical receding horizon control framework for path planning and control of autonomous vtol vehicles

    NASA Astrophysics Data System (ADS)

    Liu, C.; Chen, W.-H.

    2013-12-01

    This paper describes an integrated path planning and tracking control framework for autonomous vertical-take-off-and-landing (VTOL) vehicles, particularly quadrotors. The path planning adopts a receding horizon strategy to repeatedly plan a local trajectory that satisfies both the vehicle dynamics and obstacle-free requirement. A tracking controller is then designed to track the planned path. The differential flatness property of the quadrotor is exploited in both path planner and tracking controller designs. The proposed framework is verified by real-time simulations incorporating online optimization.

  8. High-frequency sound waves to eliminate a horizon in the mixmaster universe.

    NASA Technical Reports Server (NTRS)

    Chitre, D. M.

    1972-01-01

    From the linear wave equation for small-amplitude sound waves in a curved space-time, there is derived a geodesiclike differential equation for sound rays to describe the motion of wave packets. These equations are applied in the generic, nonrotating, homogeneous closed-model universe (the 'mixmaster universe,' Bianchi type IX). As for light rays described by Doroshkevich and Novikov (DN), these sound rays can circumnavigate the universe near the singularity to remove particle horizons only for a small class of these models and in special directions. Although these results parallel those of DN, different Hamiltonian methods are used for treating the Einstein equations.

  9. Can galaxies exist within our particle horizon with Hubble recessional velocities greater than c?

    NASA Astrophysics Data System (ADS)

    Stuckey, W. M.

    1992-02-01

    A simple, global picture of photon exchange in the flat, matter-dominated universe is presented using relativistic cosmology. Equations for the photon's recessional velocity and position relative to the receiver are derived. The results are discussed in the context of the ``raisin bread universe.'' Contrary to intuition, it is shown that the Hubble recessional velocity of the emitter can exceed the speed of light for sources within the particle horizon of the receiver. The model used to obtain these results can be used by introductory astronomy students to obtain the proper distance and the time-of-flight distance to sources with large redshifts.

  10. Less is still more: maintenance of the very brief exposure effect 1 year later.

    PubMed

    Siegel, Paul; Warren, Richard

    2013-04-01

    This study tested the hypothesis that an immediate effect of exposure to masked phobic stimuli on avoidance of the corresponding feared object would be maintained 1 year later. Fifty-three spider-phobic participants were identified with a questionnaire and a Behavioral Avoidance Test (BAT) with a live tarantula. One week later, they were administered 1 of 3 types of exposure: very brief (25-ms, masked) or clearly visible (125-ms, unmasked) images of spiders, or very brief images of flowers. They engaged in the BAT again immediately thereafter. One year later, they returned for a follow-up BAT. The immediate effect of exposure to very brief spiders on reducing avoidance of the tarantula was still evident 1 year later. Endurance of an effect by masked stimuli of this duration has not been reported before. Potential theoretical implications are discussed. PMID:23527506

  11. Fathers' Depression Related to Positive and Negative Parenting Behaviors With 1-Year-Old Children

    PubMed Central

    Davis, Matthew M.; Freed, Gary L.; Clark, Sarah J.

    2011-01-01

    OBJECTIVE: To examine the associations between depression in fathers of 1-year-old children and specific positive and negative parenting behaviors discussed by pediatric providers at well-child visits. METHODS: We performed a cross-sectional secondary analysis by using interview data from 1746 fathers of 1-year-old children in the Fragile Families and Child Wellbeing Study. Positive parenting behaviors included fathers' reports of playing games, singing songs, and reading stories to their children ≥3 days in a typical week. Negative parenting behavior included fathers' reports of spanking their 1-year-old children in the previous month. Depression was assessed by using the World Health Organization Composite International Diagnostic Interview Short Form. Weighted bivariate and multivariate analyses of parenting behaviors were performed while controlling for demographics and paternal substance abuse. RESULTS: Overall, 7% of fathers had depression. In bivariate analyses, depressed fathers were more likely than nondepressed fathers to report spanking their 1-year-old children in the previous month (41% compared with 13%; P < .01). In multivariate analyses, depressed fathers were less likely to report reading to their children ≥3 days in a typical week (adjusted odds ratio: 0.38 [95% confidence interval: 0.15–0.98]) and much more likely to report spanking (adjusted odds ratio: 3.92 [95% confidence interval: 1.23–12.5]). Seventy-seven percent of depressed fathers reported talking to their children's doctor in the previous year. CONCLUSIONS: Paternal depression is associated with parenting behaviors relevant to well-child visits. Pediatric providers should consider screening fathers for depression, discussing specific parenting behaviors (eg, reading to children and appropriate discipline), and referring for treatment if appropriate. PMID:21402627

  12. Increased 1-year survival and discharge to independent living in overweight hip fracture patients.

    PubMed

    Flodin, Lena; Laurin, Agnes; Lökk, Johan; Cederholm, Tommy; Hedström, Margareta

    2016-04-01

    Background and purpose - Hip fracture patients usually have low body mass index (BMI), and suffer further postoperative catabolism. How BMI relates to outcome in relatively healthy hip fracture patients is not well investigated. We investigated the association between BMI, survival, and independent living 1 year postoperatively. Patients and methods - This prospective multicenter study involved 843 patients with a hip fracture (mean age 82 (SD 7) years, 73% women), without severe cognitive impairment and living independently before admission. We investigated the relationship between BMI and both 1-year mortality and ability to return to independent living. Results - Patients with BMI > 26 had a lower mortality rate than those with BMI < 22 and those with BMI 22-26 (6%, 16%, and 18% respectively; p = 0.006). The odds ratio (OR) for 1-year survival in the group with BMI > 26 was 2.6 (95% CI: 1.2-5.5) after adjustment for age, sex, and physical status. Patients with BMI > 26 were also more likely to return to independent living after the hip fracture (OR = 2.6, 95% CI: 1.4-5.0). Patients with BMI < 22 had similar mortality and a similar likelihood of independent living to those with BMI 22-26. Interpretation - In this selected group of patients with hip fracture, the overweight and obese patients (BMI > 26) had a higher survival rate at 1 year, and returned to independent living to a higher degree than those of normal (healthy) weight. The obesity paradox and the recommendations for optimal BMI need further consideration in patients with hip fracture. PMID:26986549

  13. A Simple Tool to Predict ESRD Within 1 Year in Elderly Patients with Advanced CKD

    PubMed Central

    Drawz, Paul E.; Goswami, Puja; Azem, Reem; Babineau, Denise C.; Rahman, Mahboob

    2013-01-01

    BACKGROUND/OBJECTIVES Chronic kidney disease (CKD) is common in older patients; currently, no tools are available to predict the risk of end-stage renal disease (ESRD) within 1 year. The goal of this study was to develop and validate a model to predict the 1 year risk for ESRD in elderly subjects with advanced CKD. DESIGN Retrospective study SETTING Veterans Affairs Medical Center PARTICIPANTS Patients over 65 years of age with CKD with an estimated (eGFR) less than 30mL/min/1.73m2. MEASUREMENTS The outcome was ESRD within 1 year of the index eGFR. Cox regression was used to develop a predictive model (VA risk score) which was validated in a separate cohort. RESULTS Of the 1,866 patients in the developmental cohort, 77 developed ESRD. Risk factors for ESRD in the final model were age, congestive heart failure, systolic blood pressure, eGFR, potassium, and albumin. In the validation cohort, the C index for the VA risk score was 0.823. The risk for developing ESRD at 1 year from lowest to highest tertile was 0.08%, 2.7%, and 11.3% (P<0.001). The C-index for the recently published Tangri model in the validation cohort was 0.780. CONCLUSION A new model using commonly available clinical measures shows excellent ability to predict the onset of ESRD within the next year in elderly subjects. Additionally, the Tangri model had very good predictive ability. Patients and physicians can use these risk models to inform decisions regarding preparation for renal replacement therapy in patients with advanced CKD. PMID:23617782

  14. Increased 1-year survival and discharge to independent living in overweight hip fracture patients

    PubMed Central

    Flodin, Lena; Laurin, Agnes; Lökk, Johan; Cederholm, Tommy; Hedström, Margareta

    2016-01-01

    Background and purpose — Hip fracture patients usually have low body mass index (BMI), and suffer further postoperative catabolism. How BMI relates to outcome in relatively healthy hip fracture patients is not well investigated. We investigated the association between BMI, survival, and independent living 1 year postoperatively. Patients and methods — This prospective multicenter study involved 843 patients with a hip fracture (mean age 82 (SD 7) years, 73% women), without severe cognitive impairment and living independently before admission. We investigated the relationship between BMI and both 1-year mortality and ability to return to independent living. Results — Patients with BMI > 26 had a lower mortality rate than those with BMI < 22 and those with BMI 22–26 (6%, 16%, and 18% respectively; p = 0.006). The odds ratio (OR) for 1-year survival in the group with BMI > 26 was 2.6 (95% CI: 1.2–5.5) after adjustment for age, sex, and physical status. Patients with BMI > 26 were also more likely to return to independent living after the hip fracture (OR = 2.6, 95% CI: 1.4–5.0). Patients with BMI < 22 had similar mortality and a similar likelihood of independent living to those with BMI 22–26. Interpretation — In this selected group of patients with hip fracture, the overweight and obese patients (BMI > 26) had a higher survival rate at 1 year, and returned to independent living to a higher degree than those of normal (healthy) weight. The obesity paradox and the recommendations for optimal BMI need further consideration in patients with hip fracture. PMID:26986549

  15. Pretreatment standards: categorical regulations on the horizon.

    PubMed

    Casaday, J E

    1991-10-01

    As Congress writes aggressive wastewater laws and EPA tightens its regulatory grip, the question of whether to fight or compromise becomes even more pressing for the textile rental industry. As Congress moves forward on the reauthorization of the Clean Water Act, EPA's authority to issue pretreatment standards could be greatly strengthened. Categorical pretreatment standards would set national limits on the concentrations of various pollutants that are being discharged to publicly owned treatment works (POTWs). As EPA lays out its recommendations to Congress, perhaps it's time for the textile rental industry to reevaluate its position on categorical standards. PMID:10115028

  16. Impact of Renal Sympathetic Denervation on Left Ventricular Structure and Function at 1-Year Follow-Up

    PubMed Central

    de Sousa Almeida, Manuel; de Araújo Gonçalves, Pedro; Branco, Patricia; Mesquita, João; Carvalho, Maria Salomé; Dores, Helder; Silva Sousa, Henrique; Gaspar, Augusta; Horta, Eduarda; Aleixo, Ana; Neuparth, Nuno; Mendes, Miguel; Andrade, Maria João

    2016-01-01

    Background Catheter-based sympathetic renal denervation (RDN) is a recent therapeutic option for patients with resistant hypertension. However, the impact of RDN in left ventricular (LV) mass and function is not completely established. Our aim was to evaluate the effects of RDN on LV structure and function (systolic and diastolic) in patients with resistant hypertension (HTN). Methods and Results From a single centre prospective registry including 65 consecutive patients with resistant HTN submitted to RDN between July-2011 and April-2015, 31 patients with baseline and 1-year follow-up echocardiogram were included in this analysis. Mean age was 65±7 years, 48% were males, 71% had type 2 diabetes. Most had hypertension lasting for more than 10 years (90%), and were being treated with a median number of 6 anti-hypertensive drugs, including 74% on spironolactone. At 1-year, there was a significant decrease both on office SBP (176±24 to 149±13mmHg, p<0.001) and DBP (90±14 to 79±11mmHg, p<0.001), and also in 24h ABPM SBP (150±20 to 132±14mmhg, p<0.001) and DBP (83±10 to 74±9mmHg, p<0.001). There was also a significant decrease in LV mass from 152±32 to 136±34g/m2 (p<0.001), an increase in LV end diastolic volume (93±18 to 111±27 mL, p = 0.004), an increase in LV ejection fraction (65±9 to 68±9%, p = 0.001) and mitral valve E deceleration time (225±49 to 247±51ms, p = 0.015) at 1-year follow up. There were no significant changes in left atrium volume index or in the distribution of patients among the different left ventricle geometric patterns and diastolic function subgroups. Conclusions In this single centre registry of patients with resistant hypertension, renal denervation was associated with significant reduction in both office and ABPM blood pressure and a significant decrease in left ventricle mass evaluated by transthoracic echocardiogram at 1 year follow-up. PMID:26934735

  17. Early Dust Storm Season Thermal State of the Martian Atmosphere - Latest Results from the Horizon Science Experiment

    NASA Astrophysics Data System (ADS)

    Martin, T. Z.; Murphy, J. R.

    1999-09-01

    The Horizon Science Experiment (HORSE) uses the Mars Horizon Sensor Assembly on the MGS orbiter to measure 15 micrometer band thermal emission from the middle Martian atmosphere. Since mapping began in March 1999, data acquisition has been continuous, with 12 orbits/day providing rapid longitudinal coverage. The instrument's four quadrants aligned orthogonally on the Martian limb provide important coverage in local time; two quadrants fore and aft give redundant sampling of the ground track, while the other two sample +/- 1.4 hrs in local time at the equator. Equator crossing is nominally at 3 AM and 3 PM. This coverage of six local times per day for most of the planet means that the MHSA is well suited to detect diurnal temperature variations, including the semidiurnal tidal mode, which is particularly sensitive to the presence of atmospheric dust. We report recent results on the global thermal state; specific dust events; diurnal behavior; and other wavelike phenomena.

  18. Percutaneous coronary intervention in the elderly: procedural success and 1-year outcomes.

    PubMed

    Eckart, Robert E; Shry, Eric A; Simpson, Daniel E; Stajduhar, Karl C

    2003-01-01

    Clinical trials have found increased morbidity in elderly persons presenting for percutaneous coronary intervention for chronic stable angina. Long-term follow-up is limited for the elderly following percutaneous coronary intervention. The authors reviewed all coronary interventions performed from January 1998 to August 2001. One year following the procedure, subjects were screened for death, need for revascularization, and myocardial infarction. There were 401 subjects aged >/=65 years (mean 73.4+/-6.0 years) and 479 subjects aged <65 years (mean 55.6+/-6.7 years). Although there was no difference in 1-year rate of subsequent myocardial infarction or in revascularization, the elderly were more likely to die during hospitalization (4.7% vs. 1.0%, p<0.01), and at 1 year (10.2% vs. 4.0%, p<0.01). When controlled for ejection fraction, age was no longer significant in either predischarge mortality or in 1-year mortality. Excess postpercutaneous coronary intervention mortality in the elderly may be due to underlying comorbidities and not due to subsequent myocardial infarction or revascularization. PMID:14610387

  19. Infants under 1 year of age have a significant risk of burn injury.

    PubMed

    Nguyen, Dai Q A; Tobin, Sean; Dickson, William A; Potokar, Tom S

    2008-09-01

    A wealth of data exists concerning paediatric burn epidemiology in general, but very little exists specifically in infants under 1 year of age, a special group in which mobility begins to develop. A retrospective study of all burn admissions of infants under 1 year old to The Welsh Centre for Burns from January 2003 to January 2006 was performed. During the 3-year period there were 104 new burns cases identified which represents 11.8% of all paediatric admissions. 63.5% (66) were treated as inpatients and 36.5% (38) treated as out-patients. Burns increased in frequency with increasing age and occurred mainly in the home. Scalds were the commonest type of burn in 65% (68) whilst the second most common was contact burns which accounted for 30% (31). The most common source of scald was from cups containing hot drinks (39%) and the most common source of contact burn was radiators/hot water pipes (30%). The mean TBSA was 2.3%, (range 0.5-38%). The frequency of burns in the under 1 year old population highlights a need for emphasis of burn prevention directed to this group. Special attention is needed to look at the specific aetiology of these burns. Starting points for prevention should address the number of burns surrounding hot drinks and bottle warming practices in the case of scalds and the dangers of household radiators and hot water pipes in the case of contact burns. PMID:18378092

  20. Association of Postpartum Depression With Weight Retention 1 Year After Childbirth

    PubMed Central

    Herring, Sharon J.; Rich-Edwards, Janet W.; Oken, Emily; Rifas-Shiman, Sheryl L.; Kleinman, Ken P.; Gillman, Matthew W.

    2009-01-01

    Objective To examine the extent to which early postpartum depression is associated with weight retention 1 year after childbirth. Methods and Procedures In a prospective cohort study of 850 women enrolled in Project Viva, mothers reported depressive symptoms on the Edinburgh Postnatal Depression Scale (EPDS) at midpregnancy and 6 months postpartum. A score >12 indicated probable depression. We assessed associations of antenatal and postpartum depression with risk of substantial weight retention (at least 5 kg) 1 year after childbirth. Results Seven-hundred thirty-six women (87%) were not depressed during or after pregnancy, 55 (6%) experienced antenatal depression only, 22 (3%) experienced both antenatal and postpartum depression, and 37 (4%) experienced postpartum depression only. At 1 year, participants retained a mean of 0.6 kg (range −16.4 to 25.5), and 12% retained at least 5 kg. In multivariate logistic regression analyses, after adjustment for weight-related covariates, maternal sociodemographics, and parity, new-onset postpartum depression was associated with more than a doubling of risk of retaining at least 5 kg (odds ratio (OR): 2.54, 95% confidence interval (CI): 1.06, 6.09). Antenatal depression, either alone or in combination with postpartum depression, was not associated with substantial weight retention. Discussion New-onset postpartum depression was associated with substantial weight retention in the first postpartum year. Interventions to manage depressive symptoms may help reduce excess weight retained postpartum and aid in the prevention of obesity among women. PMID:18369338

  1. On further generalization of the rigidity theorem for spacetimes with a stationary event horizon or a compact Cauchy horizon

    NASA Astrophysics Data System (ADS)

    Rácz, István

    2000-01-01

    A rigidity theorem that applies to smooth electrovacuum spacetimes which represent either (A) an asymptotically flat stationary black hole or (B) a cosmological spacetime with a compact Cauchy horizon ruled by closed null geodesics was given in a recent paper by Friedrich et al (1999 Commun. Math. Phys. 204 691-707). Here we enlarge the framework of the corresponding investigations by allowing the presence of other types of matter fields. In the first part the matter fields are involved merely implicitly via the assumption that the dominant energy condition is satisfied. In the second part Einstein-Klein-Gordon (EKG), Einstein-[non-Abelian]-Higgs (E[nA]H), Einstein-[Maxwell]-Yang-Mills-dilaton (E[M]YMd) and Einstein-Yang-Mills-Higgs (EYMH) systems are studied. The black hole event horizon or, respectively, the compact Cauchy horizon of the considered spacetimes is assumed to be a smooth non-degenerate null hypersurface. It is proved that there exists a Killing vector field in a one-sided neighbourhood of the horizon in EKG, E[nA]H, E[M]YMd and EYMH spacetimes. This Killing vector field is normal to the horizon, moreover, the associated matter fields are also shown to be invariant with respect to it. The presented results provide generalizations of the rigidity theorems of Hawking (for case A) and of Moncrief and Isenberg (for case B) and, in turn, they strengthen the validity of both the black hole rigidity scenario and the strong cosmic censor conjecture of classical general relativity.

  2. Bone Mineral Density at Diagnosis of Celiac Disease and after 1 Year of Gluten-Free Diet

    PubMed Central

    Pantaleoni, Stefano; Luchino, Massimo; Adriani, Alessandro; Pellicano, Rinaldo; Stradella, Davide; Ribaldone, Davide Giuseppe; Sapone, Nicoletta; Isaia, Gian Carlo; Di Stefano, Marco; Astegiano, Marco

    2014-01-01

    Atypical or silent celiac disease may go undiagnosed for many years and can frequently lead to loss of bone mineral density, with evolution to osteopenia or osteoporosis. The prevalence of the latter conditions, in case of new diagnosis of celiac disease, has been evaluated in many studies but, due to the variability of epidemiologic data and patient features, the results are contradictory. The aim of this study was to evaluate bone mineral density by dual-energy X-ray absorptiometry in 175 consecutive celiac patients at time of diagnosis (169 per-protocol, 23 males, 146 females; average age 38.9 years). Dual-energy X-ray absorptiometry was repeated after 1 year of gluten-free diet in those with T-score value <−1 at diagnosis. Stratification of patients according to sex and age showed a higher prevalence of low bone mineral density in men older than 30 years and in women of all ages. A 1-year gluten-free diet led to a significant improvement in lumbar spine and femoral neck mean T-score value. We propose that dual-energy X-ray absorptiometry should be performed at diagnosis of celiac disease in all women and in male aged >30 years, taking into account each risk factor in single patients. PMID:25379519

  3. Bone mineral density at diagnosis of celiac disease and after 1 year of gluten-free diet.

    PubMed

    Pantaleoni, Stefano; Luchino, Massimo; Adriani, Alessandro; Pellicano, Rinaldo; Stradella, Davide; Ribaldone, Davide Giuseppe; Sapone, Nicoletta; Isaia, Gian Carlo; Di Stefano, Marco; Astegiano, Marco

    2014-01-01

    Atypical or silent celiac disease may go undiagnosed for many years and can frequently lead to loss of bone mineral density, with evolution to osteopenia or osteoporosis. The prevalence of the latter conditions, in case of new diagnosis of celiac disease, has been evaluated in many studies but, due to the variability of epidemiologic data and patient features, the results are contradictory. The aim of this study was to evaluate bone mineral density by dual-energy X-ray absorptiometry in 175 consecutive celiac patients at time of diagnosis (169 per-protocol, 23 males, 146 females; average age 38.9 years). Dual-energy X-ray absorptiometry was repeated after 1 year of gluten-free diet in those with T-score value <-1 at diagnosis. Stratification of patients according to sex and age showed a higher prevalence of low bone mineral density in men older than 30 years and in women of all ages. A 1-year gluten-free diet led to a significant improvement in lumbar spine and femoral neck mean T-score value. We propose that dual-energy X-ray absorptiometry should be performed at diagnosis of celiac disease in all women and in male aged >30 years, taking into account each risk factor in single patients. PMID:25379519

  4. Reconciling Change in Oi-Horizon 14C With Mass Loss for an Oak Forest

    SciTech Connect

    Hanson, P J; Swanston, C W; Garten, Jr., C T; Todd, D E; Trumbore, S E

    2005-06-27

    First-year litter decomposition was estimated for an upland-oak forest ecosystem using enrichment or dilution of the {sup 14}C-signature of the Oi-horizon. These isotopically-based mass-loss estimates were contrasted with measured mass-loss rates from past litterbag studies. Mass-loss derived from changes in the {sup 14}C-signature of the Oi-horizon suggested mean mass loss over 9 months of 45% which was higher than the corresponding 9-month rate extrapolated from litterbag studies ({approx}35%). Greater mass loss was expected from the isotopic approach because litterbags are known to limit mass loss processes driven by soil macrofauna (e.g., fragmentation and comminution). Although the {sup 14}C-isotope approach offers the advantage of being a non-invasive method, it exhibited high variability that undermined its utility as an alternative to routine litterbag mass loss methods. However, the {sup 14}C approach measures the residence time of C in the leaf litter, rather than the time it takes for leaves to disappear; hence radiocarbon measures are subject to C immobilization and recycling in the microbial pool, and do not necessarily reflect results from litterbag mass loss. The commonly applied two-compartment isotopic mixing model was appropriate for estimating decomposition from isotopic enrichment of near-background soils, but it produced divergent results for isotopic dilution of a multi-layered system with litter cohorts having independent {sup 14}C-signatures. This discrepancy suggests that cohort-based models are needed to adequately capture the complex processes involved in carbon transport associated with litter mass-loss. Such models will be crucial for predicting intra- and interannual differences in organic horizon decomposition driven by scenarios of climatic change.

  5. Reconciling Change in Oi-Horizon Carbon-14 with Mass Loss for an Oak Forest

    SciTech Connect

    Hanson, Paul J; Swanston, Christopher W.; Garten Jr, Charles T; Todd Jr, Donald E; Trumbore, Susan E.

    2005-01-01

    First-year litter decomposition was estimated for an upland-oak forest ecosystem using enrichment or dilution of the 14C-signature of the Oi-horizon. These isotopically-based mass-loss estimates were contrasted with measured mass-loss rates from past litterbag studies. Mass-loss derived from changes in the 14C-signature of the Oi-horizon suggested mean mass loss over 9 months of 45% which was higher than the corresponding 9-month rate extrapolated from litterbag studies (~35%). Greater mass loss was expected from the isotopic approach because litterbags are known to limit mass loss processes driven by soil macrofauna (e.g., fragmentation and comminution). Although the 14C-isotope approach offers the advantage of being a non-invasive method, it exhibited high variability that undermined its utility as an alternative to routine litterbag mass loss methods. However, the 14C approach measures the residence time of C in the leaf litter, rather than the time it takes for leaves to disappear; hence radiocarbon measures reflect C immobilization and recycling in the microbial pool, and do not necessarily replicate results from litterbag mass loss. The commonly applied two-compartment isotopic mixing model was appropriate for estimating decomposition from isotopic enrichment of near-background soils, but it produced divergent results for isotopic dilution of a multi-layered system with litter cohorts having independent 14C-signatures. This discrepancy suggests that cohort-based models are needed to adequately capture the complex processes involved in carbon transport associated with litter mass-loss. Such models will be crucial for predicting intra- and interannual differences in organic horizon decomposition driven by scenarios of climatic change.

  6. New horizons for public health in Kazakhstan.

    PubMed

    Aringazina, Altyn; Macdonald, Gordon

    2006-01-01

    This paper, the first ever to review and critique public health developments in Kazakhstan, suggests ways in which public health can be improved strategically. The paper outlines the main threats to health in a dynamic economically developing country, but argues that with a health care reform agenda in place, and the Governments apparent support of public health policy initiatives, the time is right for new opportunities in the promotion of health. The paper utilises the Ottawa Charter, but suggests novel, more appropriate headings for Kazakhstan, to galvanise policy makers and professionals into tackling the growing burden of disease. It concludes by calling for greater transparency in relation to Government policy initiatives, and the need for greater national and international collaboration. PMID:17294711

  7. Fish Eye View of Horizon and Lander

    NASA Technical Reports Server (NTRS)

    2008-01-01

    North is up (12 o'clock position) in this seam-corrected 360 degree polar projection using downsampled images from sols 1 and 3. Seam boundaries show different times of day, e.g. 9 o'clock (west) position shows scoop of RA, 7 o'clock view shows the MET mast with telltale (mast contains three temperature sensors).

    Note: hummocky terrain with troughs, typical of Earth polar terrain where we would see permafrost and ice beneath surface.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. 78 FR 33431 - Deepwater Horizon Oil Spill; Notice of Intent To Prepare a Programmatic Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ... Deepwater Horizon Oil Spill; Notice of Intent To Prepare a Programmatic Environmental Impact Statement for a... state natural resource trustees for the Deepwater Horizon oil spill (Trustees) intend to prepare a PEIS... discharges from the rig and from the wellhead on the seabed. The Deepwater Horizon oil spill is the...

  9. 33 CFR 147.T08-849 - DEEPWATER HORIZON Mobile Offshore Drilling Unit Safety Zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false DEEPWATER HORIZON Mobile Offshore... DEEPWATER HORIZON Mobile Offshore Drilling Unit Safety Zone. (a) Location. All areas within 500 meters (1640... area surrounds the DEEPWATER HORIZON, a Mobile Offshore Drilling Unit (MODU), that sank in...

  10. 78 FR 8184 - DEEPWATER HORIZON Oil Spill; Final Phase II Early Restoration Plan and Environmental Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ... DEEPWATER HORIZON Oil Spill; Final Phase II Early Restoration Plan and Environmental Review AGENCY: Interior... Addressing Injuries Resulting from the DEEPWATER HORIZON Oil Spill (Framework Agreement), notice is hereby... services injured or lost as a result of the DEEPWATER HORIZON oil spill, which occurred on or about...

  11. 77 FR 23741 - DEEPWATER HORIZON Oil Spill; Final Phase I Early Restoration Plan and Environmental Assessment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-20

    ... Fish and Wildlife Service DEEPWATER HORIZON Oil Spill; Final Phase I Early Restoration Plan and... DEEPWATER HORIZON Oil Spill (Framework Agreement), notice is hereby given that ] the Federal and State... the DEEPWATER HORIZON oil spill, which occurred on or about April 20, 2010, in the Gulf of Mexico....

  12. 50 CFR 622.14 - Area closures related to the Deepwater Horizon oil spill.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Horizon oil spill. 622.14 Section 622.14 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT... spill. (a) Caribbean EEZ area closure related to Deepwater Horizon oil spill. Effective May 11, 2010... Web site: http://sero.nmfs.noaa.gov/deepwater_horizon_oil_spill.htm. (b) Gulf EEZ area closure...

  13. 76 FR 78016 - Deepwater Horizon Oil Spill; Draft Phase I Early Restoration Plan and Environmental Assessment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-15

    ....S. Fish and Wildlife Service, Interior Deepwater Horizon Oil Spill; Draft Phase I Early Restoration... from the Deepwater Horizon Oil Spill, the Federal and State natural resource trustee agencies (Trustees... resources and services injured or lost as a result of the Deepwater Horizon oil spill, which occurred on...

  14. 78 FR 26319 - Deepwater Horizon Oil Spill; Proposal of Future Early Restoration Projects and Environmental Reviews

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-06

    ... National Oceanic and Atmospheric Administration Deepwater Horizon Oil Spill; Proposal of Future Early... Horizon oil spill (Trustees) intend to propose the additional early restoration projects described below... services, and human use services injured or lost as a result of the Deepwater Horizon oil spill...

  15. Improvement to Airport Throughput Using Intelligent Arrival Scheduling and an Expanded Planning Horizon

    NASA Technical Reports Server (NTRS)

    Glaab, Patricia C.

    2012-01-01

    The first phase of this study investigated the amount of time a flight can be delayed or expedited within the Terminal Airspace using only speed changes. The Arrival Capacity Calculator analysis tool was used to predict the time adjustment envelope for standard descent arrivals and then for CDA arrivals. Results ranged from 0.77 to 5.38 minutes. STAR routes were configured for the ACES simulation, and a validation of the ACC results was conducted comparing the maximum predicted time adjustments to those seen in ACES. The final phase investigated full runway-to-runway trajectories using ACES. The radial distance used by the arrival scheduler was incrementally increased from 50 to 150 nautical miles (nmi). The increased Planning Horizon radii allowed the arrival scheduler to arrange, path stretch, and speed-adjust flights to more fully load the arrival stream. The average throughput for the high volume portion of the day increased from 30 aircraft per runway for the 50 nmi radius to 40 aircraft per runway for the 150 nmi radius for a traffic set representative of high volume 2018. The recommended radius for the arrival scheduler s Planning Horizon was found to be 130 nmi, which allowed more than 95% loading of the arrival stream.

  16. Decentralized receding horizon control of large scale dynamically decoupled systems

    NASA Astrophysics Data System (ADS)

    Keviczky, Tamas

    Decentralized control techniques today can be found in a broad spectrum of applications ranging from robotics and formation flight to civil engineering. Their importance for dynamically decoupled systems arises from the abundance of networks of independently actuated systems and the necessity of avoiding centralized design when this becomes computationally prohibitive or would require unrealistic expectations regarding information exchange. A decentralized optimal control framework using distributed Receding Horizon Control (RHC) schemes is proposed to address this problem, which helps overcome drawbacks of currently available methods. Stability of the proposed scheme is analyzed in detail and a number of methodologies are enlisted to address the problem of feasibility. In particular, a feasible decentralized RHC scheme based on hierarchical decomposition and feasible set projection is developed. Another approach for guaranteed constraint fulfillment is described as well using invariant sets of emergency controllers and switching. A hybrid decentralized RHC framework is also introduced based on coordinating functions and logic rules. The proposed framework makes use of algorithms that rely on results from computational geometry, mathematical programming solvers, constrained optimal control, invariant set computation and hybrid systems. These techniques allow the formulation of constrained optimal control problems and the computation of their equivalent look-up tables which are easily implementable in real-time. A summary of relevant background material related to these underlying techniques is provided in this thesis as well. Applicability of the proposed framework is explored using the formation control problem of multiple Unmanned Air Vehicles (UAVs) as a motivating example. This particular application problem has a wide range of envisioned applications including distributed sensing and monitoring, which appear to be the most promising ones. The challenge in UAV

  17. Absolute Thermal SST Measurements over the Deepwater Horizon Oil Spill

    NASA Astrophysics Data System (ADS)

    Good, W. S.; Warden, R.; Kaptchen, P. F.; Finch, T.; Emery, W. J.

    2010-12-01

    Climate monitoring and natural disaster rapid assessment require baseline measurements that can be tracked over time to distinguish anthropogenic versus natural changes to the Earth system. Disasters like the Deepwater Horizon Oil Spill require constant monitoring to assess the potential environmental and economic impacts. Absolute calibration and validation of Earth-observing sensors is needed to allow for comparison of temporally separated data sets and provide accurate information to policy makers. The Ball Experimental Sea Surface Temperature (BESST) radiometer was designed and built by Ball Aerospace to provide a well calibrated measure of sea surface temperature (SST) from an unmanned aerial system (UAS). Currently, emissive skin SST observed by satellite infrared radiometers is validated by shipborne instruments that are expensive to deploy and can only take a few data samples along the ship track to overlap within a single satellite pixel. Implementation on a UAS will allow BESST to map the full footprint of a satellite pixel and perform averaging to remove any local variability due to the difference in footprint size of the instruments. It also enables the capability to study this sub-pixel variability to determine if smaller scale effects need to be accounted for in models to improve forecasting of ocean events. In addition to satellite sensor validation, BESST can distinguish meter scale variations in SST which could be used to remotely monitor and assess thermal pollution in rivers and coastal areas as well as study diurnal and seasonal changes to bodies of water that impact the ocean ecosystem. BESST was recently deployed on a conventional Twin Otter airplane for measurements over the Gulf of Mexico to access the thermal properties of the ocean surface being affected by the oil spill. Results of these measurements will be presented along with ancillary sensor data used to eliminate false signals including UV and Synthetic Aperture Radar (SAR

  18. The Exploration of the Pluto System by New Horizons

    NASA Astrophysics Data System (ADS)

    Stern, S. Alan; NASA New Horizons Team

    2016-01-01

    The Pluto system was recently explored by NASA's New Horizons spacecraft, making closest approach on 14 July 2015. Pluto's surface displays diverse landforms, terrain ages, albedos, colors, and composition gradients. Evidence is found for a water-ice crust, geologically young surface units, surface ice convection, wind streaks, volatile transport, and glacial flow. Pluto's atmosphere is highly extended, with trace hydrocarbons, a global haze layer, and a surface pressure near 10 microbars. Pluto's diverse surface geology and long term activity raise fundamental questions about how small planets remain active many billions of years (Gyr) after formation. Pluto's large moon Charon displays tectonics and evidence for a heterogeneous crustal composition; its North Pole displays puzzling dark terrain. Small satellites Hydra and Nix have higher albedos than expected. In this talk I will summarize the objectives of the New Horizons mission, its scientific payload, and survey key results obtained to date about Pluto and its system of moons.

  19. A horizon scan of global conservation issues for 2012.

    PubMed

    Sutherland, William J; Aveling, Ros; Bennun, Leon; Chapman, Eleanor; Clout, Mick; Côté, Isabelle M; Depledge, Michael H; Dicks, Lynn V; Dobson, Andrew P; Fellman, Liz; Fleishman, Erica; Gibbons, David W; Keim, Brandon; Lickorish, Fiona; Lindenmayer, David B; Monk, Kathryn A; Norris, Kenneth; Peck, Lloyd S; Prior, Stephanie V; Scharlemann, Jörn P W; Spalding, Mark; Watkinson, Andrew R

    2012-01-01

    Our aim in conducting annual horizon scans is to identify issues that, although currently receiving little attention, may be of increasing importance to the conservation of biological diversity in the future. The 15 issues presented here were identified by a diverse team of 22 experts in horizon scanning, and conservation science and its application. Methods for identifying and refining issues were the same as in two previous annual scans and are widely transferable to other disciplines. The issues highlight potential changes in climate, technology and human behaviour. Examples include warming of the deep sea, increased cultivation of perennial grains, burning of Arctic tundra, and the development of nuclear batteries and hydrokinetic in-stream turbines. PMID:22133790

  20. Deepwater Horizon oil spill impacts on Alabama beaches

    NASA Astrophysics Data System (ADS)

    Hayworth, J. S.; Clement, T. P.; Valentine, J. F.

    2011-12-01

    From mid June 2010 to early August 2010, the white sandy beaches along Alabama's Gulf coast were inundated with crude oil discharged from the Deepwater Horizon well. The long-term consequences of this environmental catastrophe are still unfolding. Although BP has attempted to clean up some of these beaches, there still exist many unanswered questions regarding the physical, chemical, and ecological state of the oil contaminated beach system. In this paper, we present our understanding of what is known and known to be unknown with regard to the current state of Alabama's beaches in the aftermath of the Deepwater Horizon disaster. Motivated by our observations of the evolving distribution of oil in Alabama's beaches and BP's clean-up activities, we offer our thoughts on the lessons learned from this oil spill disaster.

  1. Deepwater Horizon oil spill impacts on Alabama beaches

    NASA Astrophysics Data System (ADS)

    Hayworth, J. S.; Clement, T. P.; Valentine, J. F.

    2011-07-01

    From mid June 2010 to early August 2010, the white sandy beaches along Alabama's Gulf coast were inundated with crude oil discharged from the Deepwater Horizon well. The long-term consequences of this environmental catastrophe are still unfolding. Although BP has attempted to clean up some of these beaches, there still exist many unanswered questions regarding the physical, chemical, and ecological state of the oil contaminated beach system. In this paper, we present our understanding of what is known and known to be unknown with regard to the current state of Alabama's beaches in the aftermath of the Deepwater Horizon disaster. Motivated by our observations of the evolving distribution of oil in Alabama's beaches and BP's clean-up activities, we offer our thoughts on the lessons learned from this oil spill disaster.

  2. A horizon scan for species conservation by zoos and aquariums.

    PubMed

    Gusset, Markus; Fa, John E; Sutherland, William J

    2014-01-01

    We conducted the first horizon scan for zoos and aquariums to identify the 10 most important emerging issues for species conservation. This involved input from more than 100 experts from both the wider conservation community and the world zoo and aquarium community. Some of the issues are globally important: diseases, zoonoses, and biosecurity issues; new (communication) technologies; global water shortage and food insecurity; developing economies and markets for wildlife consumption; changes in wildlife population dynamics; and political instability and conflicts. Other issues are more specific to zoos and aquariums: need for extractive reserves; space shortage in zoos and aquariums; need for metapopulation management; and demand for caring of more species in zoos and aquariums. We also identified some broad approaches to these issues. Addressing the emerging issues identified in our horizon scan will further increase the contribution of the world zoo and aquarium community to global biodiversity conservation. PMID:25065560

  3. New perspectives for European climate services: HORIZON2020

    NASA Astrophysics Data System (ADS)

    Bruning, Claus; Tilche, Andrea

    2014-05-01

    The developing of new end-to-end climate services was one of the core priorities of 7th Framework for Research and Technological Development of the European Commission and will become one of the key strategic priorities of Societal Challenge 5 of HORIZON2020 (the new EU Framework Programme for Research and Innovation 2014-2020). Results should increase the competitiveness of European businesses, and the ability of regional and national authorities to make effective decisions in climate-sensitive sectors. In parallel, the production of new tailored climate information should strengthen the resilience of the European society to climate change. In this perspective the strategy to support and foster the underpinning science for climate services in HORIZON2020 will be presented.

  4. Large superconformal near-horizons from M-theory

    NASA Astrophysics Data System (ADS)

    Kelekci, Ö.; Lozano, Y.; Montero, J.; O'Colgáin, E.; Park, M.

    2016-04-01

    We report on a classification of supersymmetric solutions to 11D supergravity with S O (2 ,2 )×S O (3 ) isometry, which are AdS /CFT dual to 2D CFTs with N =(0 ,4 ) supersymmetry. We recover the Maldacena, Strominger, Witten near-horizon with small superconformal symmetry and identify a class of AdS3×S2×S2×C Y2 geometries with emergent large superconformal symmetry. This exhausts known compact geometries. Compactification of M-theory on C Y2 results in a vacuum of 7D supergravity with large superconformal symmetry, providing a candidate near-horizon for an extremal black hole and a potential new setting to address microstates.

  5. Failing a student nurse: a new horizon of moral courage.

    PubMed

    Black, Sharon; Curzio, Joan; Terry, Louise

    2014-03-01

    The factors preventing registered nurses from failing students in practice are multifaceted and have attracted much debate over recent years. However, writers rarely focus on what is needed to fail an incompetent pre-registration nursing student in their final placement. This hermeneutic study explored the mentor experience of failing a pre-registration nursing student in their final placement. A total of 19 mentors were recruited from 7 different healthcare organisations in both inner city and rural locations in the southeast of England. Participants took part in individual reflective interviews about their experience of failing a pre-registration nursing student in their final placement. These experiences were interpreted through a hermeneutic discovery of meaning. The new horizon of understanding which developed as a result of this research is framed within the context of moral stress, moral integrity and moral residue with the overall synthesis being that these mentors' stories presented a new horizon of moral courage. PMID:23989859

  6. Atmospheric Results from the MGS Horizon Science Experiment

    NASA Technical Reports Server (NTRS)

    Martin, T. Z.; Murphy, J. R.; Hollingsworth, J. L.

    1999-01-01

    The Horizon Science Experiment (HORSE) utilizes the Mars Horizon Sensor Assembly (MHSA) on the Mars Global Surveyor (MGS) orbiter to measure 15-micron band thermal emission from the Martian atmosphere. During the first two phases of aerobraking, from September 1997 to May 1998, and from September 1998 to March 1999, one of the four MGS quadrants was pointed well onto the planet consistently during the near-periapsis aerobraking passes, allowing the device to obtain data on the latitudinal variation of middle atmospheric temperature (0.2 - 2.0 mbar). Of particular interest during the first phase (L(sub s) = 182 - 300 deg) were the effects of a prominent dust storm at L(sub s) =224 deg, and wavelike behavior in the strong temperature gradient near the north polar cap. Additional information is contained in the original extended abstract.

  7. Hawking radiation and near horizon universality of chiral Virasoro algebra

    NASA Astrophysics Data System (ADS)

    Banerjee, Rabin; Gangopadhyay, Sunandan; Kulkarni, Shailesh

    2010-12-01

    We show that the diffeomorphism anomaly together with the trace anomaly reveal a chiral Virasoro algebra near the event horizon of a black hole. This algebra is the same irrespective of whether the anomaly is covariant or consistent, thereby manifesting its universal character and the fact that only the outgoing modes are relevant near the horizon. Our analysis therefore clarifies the role of the trace anomaly in the diffeomorphism anomaly approach [Robinson and Wilczek in Phys. Rev. Lett. 95:011303, 2005; Iso et al. in Phys. Rev. Lett. 96:151302, 2006; Banerjee and Kulkarni in Phys. Rev. D 77:024018, 2008; Gangopadhyay and Kulkarni in Phys. Rev. D 77:024038, 2008] to the Hawking radiation.

  8. Digital Signal Processing for the Event Horizon Telescope

    NASA Astrophysics Data System (ADS)

    Weintroub, Jonathan

    2015-08-01

    A broad international collaboration is building the Event Horizon Telescope (EHT). The aim is to test Einstein’s theory of General Relativity in one of the very few places it could break down: the strong gravity regime right at the edge of a black hole. The EHT is an earth-size VLBI array operating at the shortest radio wavelengths, that has achieved unprecedented angular resolution of a few tens of μarcseconds. For nearby super massive black holes (SMBH) this size scale is comparable to the Schwarzschild Radius, and emission in the immediate neighborhood of the event horizon can be directly observed. We give an introduction to the science behind the CASPER-enabled EHT, and outline technical developments, with emphasis on the secret sauce of high speed signal processing.

  9. Skyrme black holes in the isolated horizons formalism

    SciTech Connect

    Nielsen, Alex B.

    2006-08-15

    We study static, spherically symmetric, Skyrme black holes in the context of the assumption that they can be viewed as bound states between ordinary bare black holes and solitons. This assumption and results stemming from the isolated horizons formalism lead to several conjectures about the static black hole solutions. These conjectures are tested against the Skyrme black hole solutions. It is shown that, while there is in general good agreement with the conjectures, a crucial aspect seems to violate one of the conjectures.

  10. New Horizons Regional Education Center 1999 FIRST Robotics Competition

    NASA Technical Reports Server (NTRS)

    Purman, Richard I.

    1999-01-01

    The New Horizons Regional Education Center (NHREC) in Hampton, VA sought and received NASA funding to support its participation in the 1999 FIRST Robotics competition. FIRST, Inc. (For Inspiration and Recognition of Science and Technology) is an organization which encourages the application of creative science, math, and computer science principles to solve real-world engineering problems. The FIRST competition is an international engineering contest featuring high school, government, and business partnerships.

  11. New Horizons Regional Education Center 2001 FIRST Robotics Competition

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The New Horizons Regional Education Center (NHREC) in Hampton, VA sought and received NASA funding to support its participation in the 2001 FIRST Robotics competition. FIRST, Inc. (For Inspiration and Recognition of Science and Technology) is an organization which encourages the application of creative science, math, and computer science principles to solve real-world engineering problems. The FIRST competition is an international engineering contest featuring high school, government, and business partnerships.

  12. Typical event horizons in AdS/CFT

    NASA Astrophysics Data System (ADS)

    Avery, Steven G.; Lowe, David A.

    2016-01-01

    We consider the construction of local bulk operators in a black hole background dual to a pure state in conformal field theory. The properties of these operators in a microcanonical ensemble are studied. It has been argued in the literature that typical states in such an ensemble contain firewalls, or otherwise singular horizons. We argue this conclusion can be avoided with a proper definition of the interior operators.

  13. Neurodevelopment at 1 year of age in infants with congenital heart disease

    PubMed Central

    Dittrich, H; Bührer, C; Grimmer, I; Dittrich, S; Abdul-Khaliq, H; Lange, P E

    2003-01-01

    Objective: To assess psychomotor development and neurological sequelae in infants after surgery for congenital heart defects. Design and setting: Single institution prospective cohort study. Patients: 90 of 112 consecutive surviving infants of less than 1 year of age, without brain anomalies, conditions, or syndromes associated with delayed mental development, who underwent cardiac surgery during an 18 month period; 20 control infants with minor or no congenital heart defects. Main outcome measures: Griffiths developmental scales and standardised neurological examination at 1 year. Results: Mean (SD) developmental quotient (DQ) in index infants was 99 (10.6), compared with 106.7 (6.6) in controls (p < 0.001). DQ was lower in infants after palliative surgery (n = 16; 88 (12.2)) than after corrective surgery (n = 74; 101.4 (8.6)) (p < 0.001). Of the 90 index infants, 24 (27%) had a DQ below 93.5 (more than 2 SD below the mean of controls). Developmental delay (DQ < 93.5) was more common after palliative surgery (10/16, 63%) than after corrective surgery (14/74, 19%) (p < 0.001). Of the 90 index infants, 29 (32%) had neurological abnormalities, compared with only one of the 20 controls (5%) (p = 0.013). Neurological abnormalities were more frequent after palliative surgery (11/16, 69%) than after corrective surgery (18/74, 24%) (p < 0.001). Conclusions: There is a considerable rate of neurodevelopmental impairment at 1 year of age in infants after cardiac surgery. Psychomotor impairment and neurological sequelae are apparently more severe in infants in whom only palliative surgery is possible. PMID:12639876

  14. The value of pre-operative multicompartment pelvic floor ultrasonography: a 1-year prospective study

    PubMed Central

    Lone, F; Stankiewicz, A; Thakar, R

    2014-01-01

    Objective: Comprehensive assessment of the pelvic floor (PF) provides information and diagnoses of coexisting abnormalities that may affect operative decisions. Our aim was to establish if pre-operative PF ultrasonography (PFUS) in patients complaining of PF dysfunction can complement clinical findings and contribute to additional management strategies. Methods: Females were recruited from the urogynaecology/gynaecology clinics between July and October 2009 and underwent pelvic organ prolapse quantification (POPQ) by an independent examiner. PFUS was performed using two-dimensional (2D) transperineal ultrasound (TPUS), high-frequency 2D/three-dimensional (3D) endovaginal ultrasound (EVUS) using a biplane probe with linear and transverse arrays and a 360° rotational 3D-EVUS. The clinician performing PFUS was blinded to POPQ results. POPQ and PFUS were repeated at 1 year. Two clinicians analysed the scans independently. Results: 158 of 160 females had a POPQ and PFUS. 105 females had pelvic organ prolapse and/or incontinence and 53 asymptomatic females were controls. 26 additional ultrasound diagnoses were noted at baseline and 46 at 1 year using 2D-TPUS and EVUS. Only one female with additional diagnoses on PFUS needed surgical intervention for this condition. Conclusion: Multicompartment PFUS identifies additional conditions to that diagnosed on clinical assessment. However, it neither changes the initial surgical management nor the management at 1-year follow-up and therefore clinical assessment should not be substituted by PFUS. Advances in knowledge: PFUS can be helpful in providing additional information; however, it does not change the initial management of the patient and therefore should not replace clinical assessment. PMID:24959953

  15. Hawking spectrum for a fiber-optical analog of the event horizon

    NASA Astrophysics Data System (ADS)

    Bermudez, David; Leonhardt, Ulf

    2016-05-01

    Hawking radiation has been regarded as a more general phenomenon than in gravitational physics, in particular in laboratory analogs of the event horizon. Here we consider the fiber-optical analog of the event horizon, where intense light pulses in fibers establish horizons for probe light. Then, we calculate the Hawking spectrum in an experimentally realizable system. We found that the Hawking radiation is peaked around group-velocity horizons in which the speed of the pulse matches the group velocity of the probe light. The radiation nearly vanishes at the phase horizon where the speed of the pulse matches the phase velocity of light.

  16. Risk and protective factors for peer victimization: a 1-year follow-up study of urban American students.

    PubMed

    Karlsson, Elisabeth; Stickley, Andrew; Lindblad, Frank; Schwab-Stone, Mary; Ruchkin, Vladislav

    2014-09-01

    This study examined whether internalizing problems, parental warmth and teacher support were associated with adolescents' experience of future peer victimization in school. Data were drawn from two rounds of the longitudinal Social and Health Assessment (SAHA). Study subjects comprised 593 US urban adolescents (aged 13.8 ± 0.8 years; 56 % female). Results showed that there was a substantial degree of continuity in peer victimization over a 1-year period. The presence of internalizing (anxiety, depressive and somatic) symptoms at baseline was associated with an increased risk of peer victimization over time. Both parental warmth and teacher support were uniquely associated with a lower risk for peer victimization. Implications of these findings for prevention efforts are discussed. PMID:24346176

  17. High energy particle collisions and geometry of horizon

    NASA Astrophysics Data System (ADS)

    Zaslavskii, O. B.

    2016-06-01

    We consider collision of two geodesic particles near the lightlike surface (black hole horizon or naked singularity) of such an axially symmetric rotating or static metric that the coefficient gϕϕ → 0 on this surface. It is shown that the energy in the center of mass frame Ec.m. is indefinitely large even without fine-tuning of particles’ parameters. Kinematically, this is the collision between two rapid particles that approach the horizon almost with the speed of light but at different angles (or they align along the normal to the horizon too slowly). The latter is the reason why the relative velocity tends to that of light, hence to high Ec.m.. Our approach is model-independent. It relies on general properties of geometry and is insensitive to the details of material source that supports the geometries of the type under consideration. For several particular models (the stringy black hole, the Brans-Dicke analogue of the Schwarzschild metric and the Janis-Newman-Winicour one) we recover the results found in literature previously.

  18. Horizons and free-path distributions in quasiperiodic Lorentz gases.

    PubMed

    Kraemer, Atahualpa S; Schmiedeberg, Michael; Sanders, David P

    2015-11-01

    We study the structure of quasiperiodic Lorentz gases, i.e., particles bouncing elastically off fixed obstacles arranged in quasiperiodic lattices. By employing a construction to embed such structures into a higher-dimensional periodic hyperlattice, we give a simple and efficient algorithm for numerical simulation of the dynamics of these systems. This same construction shows that quasiperiodic Lorentz gases generically exhibit a regime with infinite horizon, that is, empty channels through which the particles move without colliding, when the obstacles are small enough; in this case, the distribution of free paths is asymptotically a power law with exponent -3, as expected from infinite-horizon periodic Lorentz gases. For the critical radius at which these channels disappear, however, a new regime with locally finite horizon arises, where this distribution has an unexpected exponent of -5, previously observed only in a Lorentz gas formed by superposing three incommensurable periodic lattices in the Boltzmann-Grad limit where the radius of the obstacles tends to zero. PMID:26651670

  19. Volatile Transport Implications from the New Horizons Flyby of Pluto

    NASA Astrophysics Data System (ADS)

    Young, Leslie; Grundy, William M.; Binzel, RIchard P.; Earle, Alissa M.; Linscott, Ivan R.; Hinson, David P.; Zangari, Amanda M.; McKinnon, William B.; Stern, S. Alan; Weaver, Harold A.; Olkin, Catherine B.; Ennico, Kimberly; Gladstone, G. Randall; Summers, Michael E.; Moore, Jeffrey M.; Spencer, John R.

    2015-11-01

    The New Horizons flyby of Pluto has revealed a striking range of terrains, from the very bright region informally named Sputnik Planum, to very dark regions such as the informally named Cthulhu Regio. Such a variety was beyond the scope of recent models of Pluto's seasonal volatile cycle (Young 2013, ApJL 766, L22; Hansen, Paige and Young 2015, Icarus 246, 183), which assumed globally uniform substrate albedos. The "Exchange with Pressure Plateau (EPP)" class of models in Young (2013) and the favored runs from Hansen et al (2015) had long periods of exchange of volatiles between northern and southern hemispheres. In these models, the equators were largely devoid of volatiles; even though the equatorial latitudes received less insolation than the poles over a Pluto year, they were never the coldest place on the icy world. New models that include a variety of substrate albedos can investigate questions such as whether Sputnik Planum has an albedo that is high enough to act as a local cold trap for much of Pluto's year. We will present the implications of this and other assumption-busting revelations from the New Horizons flyby. This work was supported by NASA’s New Horizons project.

  20. Accretion and origin of organic horizons in Mississippi delta

    SciTech Connect

    Kosters, E.C.; Chmura, G.L.; McBride, R.A.

    1986-05-01

    Barataria basin is a large-scale interdistributary basin of the Mississippi delta, measuring about 150 km from its apex to the Gulf of Mexico. The basin developed about 2500 years ago as a result of the interplay of different deltaic distributary systems. The data base consists of about one hundred 7.5-cm-diameter, 3 to 10-m-deep vibracores, and about fifty 15-cm-diameter, 50-cm-deep hand-held cores. Lithology, moisture/ash data, x-ray radiographs, pollen counts, and carbon isotope information are some of the parameters used to aid in the interpretation of the sedimentary and ecological origin of the different organic horizons. Organic facies are (incipient) organic-poor marsh (5-35% organic matter by dry weight), organic-rich marsh (35-75% organic matter), and true peat (75% organic matter). Organic facies occur as more or less distinct horizons; contacts between organic and detrital clastic strata are generally sharp. Each horizon of a certain quality range is thought to be the result of somewhat similar original conditions, such as botanical parent material, salinity regime, detrital clastic influx, and subsidence rates.