Science.gov

Sample records for 100-year time horizon

  1. Opening the 100-Year Window for Time-Domain Astronomy

    NASA Astrophysics Data System (ADS)

    Grindlay, Jonathan; Tang, Sumin; Los, Edward; Servillat, Mathieu

    2012-04-01

    The large-scale surveys such as PTF, CRTS and Pan-STARRS-1 that have emerged within the past 5 years or so employ digital databases and modern analysis tools to accentuate research into Time Domain Astronomy (TDA). Preparations are underway for LSST which, in another 6 years, will usher in the second decade of modern TDA. By that time the Digital Access to a Sky Century @ Harvard (DASCH) project will have made available to the community the full sky Historical TDA database and digitized images for a century (1890-1990) of coverage. We describe the current DASCH development and some initial results, and outline plans for the ``production scanning'' phase and data distribution which is to begin in 2012. That will open a 100-year window into temporal astrophysics, revealing rare transients and (especially) astrophysical phenomena that vary on time-scales of a decade. It will also provide context and archival comparisons for the deeper modern surveys.

  2. 100 years of relativity. Space-time structure: Einstein and beyond

    NASA Astrophysics Data System (ADS)

    Ashtekar, Abhay

    2005-11-01

    Thanks to Einstein's relativity theories, our notions of space and time underwent profound revisions about a 100 years ago. The resulting interplay between geometry and physics has dominated all of fundamental physics since then. This volume contains contributions from leading researchers, worldwide, who have thought deeply about the nature and consequences of this interplay. The articles take a long-range view of the subject and distill the most important advances in broad terms, making them easily accessible to non-specialists. The first part is devoted to a summary of how relativity theories were born (J. Stachel). The second part discusses the most dramatic ramifications of general relativity, such as black holes (P. Chrusciel and R. Price), space-time singularities (H. Nicolai and A. Rendall), gravitational waves (P. Laguna and P. Saulson), the large scale structure of the cosmos (T. Padmanabhan); experimental status of this theory (C. Will) as well as its practical application to the GPS system (N. Ashby). The last part looks beyond Einstein and provides glimpses into what is in store for us in the 21st century. Contributions here include summaries of radical changes in the notions of space and time that are emerging from quantum field theory in curved space-times (Ford), string theory (T. Banks), loop quantum gravity (A. Ashtekar), quantum cosmology (M. Bojowald), discrete approaches (Dowker, Gambini and Pullin) and twistor theory (R Penrose).

  3. Inner and outer horizons of time experience.

    PubMed

    Wackermann, Jirí

    2007-05-01

    Human experience of temporal durations exhibits a multi-regional structure, with more or less distinct boundaries, or horizons, on the scale of physical duration. The inner horizons are imposed by perceptual thresholds for simultaneity (approximately equal to 3 ms) and temporal order (approximatly equal to 30 ms), and are determined by the dynamical properties of the neural substrate integrating sensory information. Related to the inner horizon of experienced time are perceptual or cognitive "moments." Comparative data on autokinetic times suggest that these moments may be relatively invariant (approximately equal to 10(2) ms) across a wide range of species. Extension of the "sensible present" (approximately equal to 3 s) defines an intermediate horizon, beyond which the generic experience of duration develops. The domain of immediate duration experience is delimited by the ultimate outer horizon at about = 10(2) s, as evidenced by analysis of duration reproduction experiments (reproducibility horizon), probably determined by relaxation times of "neural accumulators." Beyond these phenomenal horizons, time is merely cognitively (re)constructed, not actually experienced or "perceived," a fact that is frequently ignored by contemporary time perception research. The nyocentric organization of time experience shows an interesting analogy with the egocentric organization of space, suggesting that structures of subjective space and time are derived from active motion as a common experiential basis.

  4. 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

  5. NETL: The First 100 Years

    ScienceCinema

    None

    2016-07-12

    The National Energy Technology Laboratory celebrates 100 years of innovative energy technology development. NETL has been a leader in energy technology development. This video takes a look back at the many accomplishments over the past 100 years. These advances benefit the American people, enhance our nation's energy security and protect our natural resources.

  6. NETL: The First 100 Years

    SciTech Connect

    2015-07-21

    The National Energy Technology Laboratory celebrates 100 years of innovative energy technology development. NETL has been a leader in energy technology development. This video takes a look back at the many accomplishments over the past 100 years. These advances benefit the American people, enhance our nation's energy security and protect our natural resources.

  7. 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.

  8. 100 Years of ACCU Leadership.

    ERIC Educational Resources Information Center

    Simmons, Andrew N.

    1999-01-01

    Chronicles the administrative organization and governance of the Association of Catholic Colleges and Universities over its 100-year history, especially the membership and role of the executive committee and major organizational changes. A chart and timeline lists leaders since 1899. (MSE)

  9. Fractal markets: Liquidity and investors on different time horizons

    NASA Astrophysics Data System (ADS)

    Li, Da-Ye; Nishimura, Yusaku; Men, Ming

    2014-08-01

    In this paper, we propose a new agent-based model to study the source of liquidity and the “emergent” phenomenon in financial market with fractal structure. The model rests on fractal market hypothesis and agents with different time horizons of investments. What is interesting is that though the agent-based model reveals that the interaction between these heterogeneous agents affects the stability and liquidity of the financial market the real world market lacks detailed data to bring it to light since it is difficult to identify and distinguish the investors with different time horizons in the empirical approach. results show that in a relatively short period of time fractal market provides liquidity from investors with different horizons and the market gains stability when the market structure changes from uniformity to diversification. In the real world the fractal structure with the finite of horizons can only stabilize the market within limits. With the finite maximum horizons, the greater diversity of the investors and the fractal structure will not necessarily bring more stability to the market which might come with greater fluctuation in large time scale.

  10. 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.

  11. 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…

  12. The AAS: Its Next 100 Years

    NASA Astrophysics Data System (ADS)

    Wolff, S.

    1999-05-01

    The AAS: Its Next Hundred Years "We are probably nearing the limit of all we can know about astronomy."-- Simon Newcomb, 1888. The best way to celebrate the centennial of the AAS is to look forward, not backward, and to begin planning for the next 100 years. However, predicting the future is even more difficult than it was in Newcomb's time. We live in an era characterized by an unprecedented rate of change in the kinds of scientific questions we ask, the tools we use to answer them, and the way we communicate our results. This talk will highlight some of the issues that we will face as a community during the next 10--but not the next 100!--years and suggests that the AAS has a fundamental role to play in shaping the community response to these issues.

  13. 100 years of Philips Research

    NASA Astrophysics Data System (ADS)

    van Delft, Dirk

    2014-03-01

    On Thursday 23 October 1913, a Dutch newspaper published the following advertisement: Hiring: A capable young scientist with a doctorate in physics. Must be a good experimenter. Letters containing information on age, life history and references may be submitted to Philips in Eindhoven. Two days later, a candidate applied: Gilles Holst. At that time, Holst was working in Leiden as an assistant to Heike Kamerlingh Onnes, a recent Nobel Prize winner.

  14. Generalized Robertson-Walker Space-Time Admitting Evolving Null Horizons Related to a Black Hole Event Horizon.

    PubMed

    Duggal, K L

    2016-01-01

    A new technique is used to study a family of time-dependent null horizons, called "Evolving Null Horizons" (ENHs), of generalized Robertson-Walker (GRW) space-time [Formula: see text] such that the metric [Formula: see text] satisfies a kinematic condition. This work is different from our early papers on the same issue where we used (1 + n)-splitting space-time but only some special subcases of GRW space-time have this formalism. Also, in contrast to previous work, we have proved that each member of ENHs is totally umbilical in [Formula: see text]. Finally, we show that there exists an ENH which is always a null horizon evolving into a black hole event horizon and suggest some open problems.

  15. Generalized Robertson-Walker Space-Time Admitting Evolving Null Horizons Related to a Black Hole Event Horizon

    PubMed Central

    2016-01-01

    A new technique is used to study a family of time-dependent null horizons, called “Evolving Null Horizons” (ENHs), of generalized Robertson-Walker (GRW) space-time (M¯,g¯) such that the metric g¯ satisfies a kinematic condition. This work is different from our early papers on the same issue where we used (1 + n)-splitting space-time but only some special subcases of GRW space-time have this formalism. Also, in contrast to previous work, we have proved that each member of ENHs is totally umbilical in (M¯,g¯). Finally, we show that there exists an ENH which is always a null horizon evolving into a black hole event horizon and suggest some open problems. PMID:27722202

  16. 100 Years of the Physics of Diodes

    NASA Astrophysics Data System (ADS)

    Luginsland, John

    2013-10-01

    The Child-Langmuir Law (CL), discovered 100 years ago, gives the maximum current that can be transported across a planar diode in the steady state. As a quintessential example of the impact of space-charge shielding near a charged surface, it is central to the studies of high current diodes, such as high power microwave sources, vacuum microelectronics, electron and ion sources, and high current drivers used in high-energy density physics experiments. CL remains a touchstone of fundamental sheath physics, including contemporary studies of nano-scale quantum diodes and plasmonic devices. Its solid state analog is the Mott-Gurney law, governing the maximum charge injection in solids, such as organic materials and other dielectrics, which is important to energy devices, such as solar cells and light-emitting diodes. This paper reviews the important advances in the physics of diodes since the discovery of CL, including virtual cathode formation and extension of CL to multiple dimensions, to the quantum regime, and to ultrafast processes. We will review the influence of magnetic fields, multiple species in bipolar flow, electromagnetic and time dependent effects in both short pulse and high frequency THz limits, and single electron regimes. Transitions from various emission mechanisms (thermionic, field, and photo-emission) to the space charge limited state (CL) will be addressed, especially highlighting important simulation and experimental developments in selected contemporary areas of study. This talk will stress the fundamental physical links between the physics of beams to limiting currents in other areas, such as low temperature plasmas, laser plasmas, and space propulsion. Also emphasized is the role of non-equilibrium phenomena associated with materials and plasmas in close contact. Work supported by the Air Force Office of Scientific Research.

  17. Convergence: Human Intelligence The Next 100 Years

    ERIC Educational Resources Information Center

    Fluellen, Jerry E., Jr.

    2005-01-01

    How might human intelligence evolve over the next 100 years? This issue paper explores that idea. First, the paper summarizes five emerging perspectives about human intelligence: Howard Gardner's multiple intelligences theory, Robert Sternberg's triarchic theory of intelligence, Ellen Langer's mindfulness theory, David Perkins' learnable…

  18. 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

  19. Gas turbines fire up after 100 years

    SciTech Connect

    Zink, J.C.

    1996-06-01

    It`s a familiar story. The ancient Greeks, Romans or Egyptians discovered a major physical principle and demonstrated it in a device that can be regarded as the forerunner of some modern technology. Then, as the industrial age dawned, various tinkerers constructed machines using these basic principles but found serious problems that couldn`t be solved with the technology then available. Finally, a ``cost is no object`` program fostered by military needs brings the device to life and, ultimately, gives it a form that is commercially suitable. This article describes how gas turbines have progressed from the theoretical to the commonplace in 100 years.

  20. Remembering Robert Goddard's vision 100 years later

    NASA Astrophysics Data System (ADS)

    Stern, David P.

    “Life, liberty, and the pursuit of happiness” —such are the goals of most of us.Yet a few always exist who feel called by a higher purpose. Society often owes them a great deal.Robert Hutchins Goddard, whose work made spaceflight possible, found his vision 100 years ago this October as a youth of 17. His family was staying on the farm of a relative, when he was asked to trim the branches of a cherry tree behind the barn.

  1. Adolescent medicine with a 100 year perspective.

    PubMed

    Hardoff, Daniel; Eisenstein, Evelyn

    2004-01-01

    Adolescent medicine was born out of scientific advances from a wide variety of disciplines, changes in societal mores and the explosion of technology that occurred during the 20th century. The past 100 years of clinical practice and research have provided a wealth of information that has improved our understanding of the biologic and physical development of adolescents as well as the epidemiology of high-risk adolescent behaviors. The present challenge for all providers of health care to adolescents is to continue to examine the effect of these high-risk behaviors and develop mechanisms to address and limit the impact of these behaviors, just as the scientists and practitioners of the 20th century made great strides in treatment and cure of medical illnesses. With a broad base of scientific knowledge, formalization into an academic field and strong government and organizational support adolescent medicine are energized by these factors and can only envision continued growth in this important field of medicine.

  2. Geiger-Marsden experiments: 100 years on

    NASA Astrophysics Data System (ADS)

    Rowley, Neil

    2012-09-01

    The perceptive analysis of Rutherford, celebrated at this conference, turned the experiments of Geiger and Marsden into a measurement of the radius of the object that became known as the atomic "nucleus". We now know that the nucleus can have a range of radii that depend on its static and dynamical deformations. These deformations give rise to the distributions of reaction barriers that have been extensively studied over recent years. While fusion reactions are most often used for such studies, there are cases where, for physical or practical reasons, the scattering channels must be exploited. Despite the major advantages gained from modern experimental techniques, the resulting experiments are in spirit essentially the same as those performed over 100 years ago by Rutherford and his colleagues.

  3. The Psychoanalytic Review: 100 years of history.

    PubMed

    Barnett, Alan J

    2013-02-01

    This paper is written in celebration of the centenary of The Psychoanalytic Review and aims to bring to life its entire history-100 years of publication. Almost as old as psychoanalysis itself, established by Jelliffe and White as a nonorthodox journal, and guided by all its subsequent editors, the Review has maintained its original mission: to serve as an open venue for all psychoanalytic perspectives, "a free forum for all." But the history of the Review is not without controversy. Freud made no original contributions to the Review. The paper unveils the Review's, rich history by looking briefly into the lives of some of its editors, the circumstances surrounding the creation of the Review (including pertinent correspondence between Freud and Brill and between Freud and Jelliffe), the years (with their engrossing politics) that followed the establishment of the Review until its merger with the journal Psychoanalysis (the official journal of NPAP), and the years that followed the merger to the present, including some of the important events that reshaped psychoanalysis. The role of the Review in promoting and reflecting almost the entire evolution of psychoanalysis is illustrated throughout.

  4. 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...

  5. The AOCS publications: a 100 year history

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The growth of societies and its associated publications is an indicator of how chemistry, a society such as AOCS, and the fats and oils industry have grown over time. During the late 18th century a shift from monographs to chemical periodicals occurred. Since then journals have been the preferred ...

  6. The 100 year DASCH Transient Search

    NASA Astrophysics Data System (ADS)

    Miller, George F.; Grindlay, J. E.; Tang, S.; Los, E.

    2014-01-01

    The Digital Access to a Sky Century at Harvard (DASCH) project is currently digitizing the roughly 500,000 photographic plates maintained by the Harvard College Observatory. The Harvard plate collection covers each point of the sky roughly 500 to 3000 times from 1885 to 1992, with limiting magnitudes ranging from B=14-18 mag and photometric accuracy within ±0.1 mag. Production scanning (up to 400 plates/day) is proceeding in Galactic coordinates from the North Galactic Pole and is currently at roughly 50 degrees galactic latitude. The vastness of these data makes the DASCH project ideal to search for transient behavior. In particular, the large time base of the DASCH collection gives an unprecedented advantage when searching for outbursting systems with recurrence rates of decades or longer. These include recurrent novae, rare WZ Sge Cataclysmic Variables, blazars, X-Ray binaries, and supernovae in the Virgo Supercluster. We report here the discovery of previously unidentified stellar-like objects that underwent abnormally large (Δm=5-9) outbursts discovered with DASCH. We also report the discovery of outbursts from previously quiet AM CVn stars, as well as attempt to characterize their recurrence rates.

  7. Uniqueness theorem for black hole space-times with multiple disconnected horizons

    NASA Astrophysics Data System (ADS)

    Armas, Jay; Harmark, Troels

    2010-05-01

    We show uniqueness of stationary and asymptotically flat black hole spacetimes with multiple disconnected horizons and with two rotational Killing vector fields in the context of five-dimensional minimal supergravity (Einstein-Maxwell-Chern-Simons gravity). The novelty in this work is the introduction in the uniqueness theorem of intrinsic local charges measured near each horizon as well as the measurement of local fluxes besides the asymptotic charges that characterize a particular solution. A systematic method of defining the boundary conditions on the fields that specify a black hole space-time is given based on the study of its rod structure (domain structure). Also, an analysis of known solutions with disconnected horizons is carried out as an example of an application of this theorem. ”But the perfect scientist is also a gardener: he believes that beauty is knowledge.” Gonçalo M. Tavares in Brief Notes on Science

  8. Nuclear and Radiochemistry: the First 100 Years

    NASA Astrophysics Data System (ADS)

    Friedlander, G.; Herrmann, G.

    This chapter gives a brief overview of the development of nuclear and radiochemistry from Mme. Curie's chemical isolation of radium toward the end of the twentieth century. The first four sections deal with fairly distinct time periods: (1) the pioneering years when the only radioactive materials available were the naturally occurring ones; (2) the decade of rapid growth and expansion of both the fundamental science and its applications following the discoveries of the neutron and artificial radioactivity; (3) the World War II period characterized by the intense exploration of nuclear fission and its ramifications; (4) what can be called the “golden era” - the 3 to 4 decades following World War II when nuclear science was generously supported and therefore flourished. In the final section, research trends pursued near the end of the century are briefly touched upon.

  9. 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

    ...; 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... discharge of crude oil into the Gulf of Mexico, which was thereafter declared a ``Spill of...

  10. 100 years of the physics of diodes

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Valfells, Ágúst; Ang, L. K.; Luginsland, J. W.; Lau, Y. Y.

    2017-03-01

    The Child-Langmuir Law (CL), discovered a century ago, gives the maximum current that can be transported across a planar diode in the steady state. As a quintessential example of the impact of space charge shielding near a charged surface, it is central to the studies of high current diodes, such as high power microwave sources, vacuum microelectronics, electron and ion sources, and high current drivers used in high energy density physics experiments. CL remains a touchstone of fundamental sheath physics, including contemporary studies of nanoscale quantum diodes and nano gap based plasmonic devices. Its solid state analog is the Mott-Gurney law, governing the maximum charge injection in solids, such as organic materials and other dielectrics, which is important to energy devices, such as solar cells and light emitting diodes. This paper reviews the important advances in the physics of diodes since the discovery of CL, including virtual cathode formation and extension of CL to multiple dimensions, to the quantum regime, and to ultrafast processes. We review the influence of magnetic fields, multiple species in bipolar flow, electromagnetic and time dependent effects in both short pulse and high frequency THz limits, and single electron regimes. Transitions from various emission mechanisms (thermionic-, field-, and photoemission) to the space charge limited state (CL) will be addressed, especially highlighting the important simulation and experimental developments in selected contemporary areas of study. We stress the fundamental physical links between the physics of beams to limiting currents in other areas, such as low temperature plasmas, laser plasmas, and space propulsion.

  11. 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.

  12. 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.

  13. The Horizon-AGN simulation: evolution of galaxy properties over cosmic time

    NASA Astrophysics Data System (ADS)

    Kaviraj, S.; Laigle, C.; Kimm, T.; Devriendt, J. E. G.; Dubois, Y.; Pichon, C.; Slyz, A.; Chisari, E.; Peirani, S.

    2017-01-01

    We compare the predictions of Horizon-AGN, a hydro-dynamical cosmological simulation that uses an adaptive mesh refinement code, to observational data in the redshift range 0 < z < 6. We study the reproduction, by the simulation, of quantities that trace the aggregate stellar-mass growth of galaxies over cosmic time: luminosity and stellar-mass functions, the star formation main sequence, rest-frame UV-optical-near infrared colours and the cosmic star-formation history. We show that Horizon-AGN, which is not tuned to reproduce the local Universe, produces good overall agreement with these quantities, from the present day to the epoch when the Universe was 5% of its current age. By comparison to Horizon-noAGN, a twin simulation without AGN feedback, we quantify how feedback from black holes is likely to help shape galaxy stellar-mass growth in the redshift range 0 < z < 6, particularly in the most massive galaxies. Our results demonstrate that Horizon-AGN successfully captures the evolutionary trends of observed galaxies over the lifetime of the Universe, making it an excellent tool for studying the processes that drive galaxy evolution and making predictions for the next generation of galaxy surveys.

  14. 100 years of sedimentation study by the USGS

    USGS Publications Warehouse

    Glysson, G. Douglas

    1989-01-01

    On January 15, 1889, the U.S. Geological Survey began collecting sediment data on the Rio Grande at Embudo, New Mexico. During the past 100 years the U.S. Geological Survey's Water Resources Division (WRD) has collected daily sediment data at more than 1,200 sites. Projects have addressed the problems associated with reservoir construction, agricultural irrigation projects, energy production, and transport and deposition of pollutants sorbed to sediments. The Survey has been active as a charter member of the Federal Interagency Sediment Project and currently has three full-time hydrologists working on the project. The WRD's sediment-research projects have covered a wide variety of subjects from the fundamental theories of resistance to flow and sediment transport in alluvial channels to lunar erosion mechanisms.

  15. Nonstationary discrete-time deterministic and stochastic control systems with infinite horizon

    NASA Astrophysics Data System (ADS)

    Guo, Xianping; Hernández-del-Valle, Adrián; Hernández-Lerma, Onésimo

    2010-09-01

    This article is about nonstationary nonlinear discrete-time deterministic and stochastic control systems with Borel state and control spaces, possibly noncompact control constraint sets, and unbounded costs. The control problem is to minimise an infinite-horizon total cost performance index. Using dynamic programming arguments we show that, under suitable assumptions, the optimal cost functions satisfy optimality equations, which in turn give a procedure to find optimal control policies.

  16. Bayesian Techniques for Comparing Time-dependent GRMHD Simulations to Variable Event Horizon Telescope Observations

    NASA Astrophysics Data System (ADS)

    Kim, Junhan; Marrone, Daniel P.; Chan, Chi-Kwan; Medeiros, Lia; Özel, Feryal; Psaltis, Dimitrios

    2016-12-01

    The Event Horizon Telescope (EHT) is a millimeter-wavelength, very-long-baseline interferometry (VLBI) experiment that is capable of observing black holes with horizon-scale resolution. Early observations have revealed variable horizon-scale emission in the Galactic Center black hole, Sagittarius A* (Sgr A*). Comparing such observations to time-dependent general relativistic magnetohydrodynamic (GRMHD) simulations requires statistical tools that explicitly consider the variability in both the data and the models. We develop here a Bayesian method to compare time-resolved simulation images to variable VLBI data, in order to infer model parameters and perform model comparisons. We use mock EHT data based on GRMHD simulations to explore the robustness of this Bayesian method and contrast it to approaches that do not consider the effects of variability. We find that time-independent models lead to offset values of the inferred parameters with artificially reduced uncertainties. Moreover, neglecting the variability in the data and the models often leads to erroneous model selections. We finally apply our method to the early EHT data on Sgr A*.

  17. Real-time moving horizon estimation for a vibrating active cantilever

    NASA Astrophysics Data System (ADS)

    Abdollahpouri, Mohammad; Takács, Gergely; Rohaľ-Ilkiv, Boris

    2017-03-01

    Vibrating structures may be subject to changes throughout their operating lifetime due to a range of environmental and technical factors. These variations can be considered as parameter changes in the dynamic model of the structure, while their online estimates can be utilized in adaptive control strategies, or in structural health monitoring. This paper implements the moving horizon estimation (MHE) algorithm on a low-cost embedded computing device that is jointly observing the dynamic states and parameter variations of an active cantilever beam in real time. The practical behavior of this algorithm has been investigated in various experimental scenarios. It has been found, that for the given field of application, moving horizon estimation converges faster than the extended Kalman filter; moreover, it handles atypical measurement noise, sensor errors or other extreme changes, reliably. Despite its improved performance, the experiments demonstrate that the disadvantage of solving the nonlinear optimization problem in MHE is that it naturally leads to an increase in computational effort.

  18. Chert horizons as time-stratigraphic markers in Ordovician and Silurian of eastern Great Basin

    SciTech Connect

    Cameron, G.J.

    1986-08-01

    Data from numerous measured sections show that distinct chert horizons occur at or near the same stratigraphic intervals in a number of Ordovician and Silurian dolomite sequences in the eastern Great basin of Nevada and Utah. In many cases a shallow-water origin for the chert is inferred because of silicified shelfal fauna and lack of deeper water indicators. The cherty intervals appear to transgress across environmentally controlled lithologic boundaries. This fact, coupled with the regional extent of the chert, suggests that these intervals can be used as time-stratigraphic marker horizons. This concept is useful in assessing the degree of stratigraphic thinning of Upper Silurian strata along a regional unconformity. Although chert is almost ubiquitously present in certain stratigraphic intervals, the abundance of chert-bearing horizons within an individual section varies. By contouring the abundance of chert-bearing intervals within the Silurian system, a well-defined pattern is documented that increases in abundance to the northeast toward the northwestern corner of Utah. The ratio of chert to dolomite within the intervals increases correspondingly. It is suggested that the chert is the result of silica supersaturation from the settling of wind-blow volcanic ash on the Silurian epicontinental sea. The distribution of the chert was largely a function of paleowind currents from an easterly or northerly active volcanic source area.

  19. 100-Year Flood-It's All About Chance

    USGS Publications Warehouse

    Holmes, Jr., Robert R.; Dinicola, Karen

    2010-01-01

    In the 1960's, the United States government decided to use the 1-percent annual exceedance probability (AEP) flood as the basis for the National Flood Insurance Program. The 1-percent AEP flood was thought to be a fair balance between protecting the public and overly stringent regulation. Because the 1-percent AEP flood has a 1 in 100 chance of being equaled or exceeded in any 1 year, and it has an average recurrence interval of 100 years, it often is referred to as the '100-year flood'. The term '100-year flood' is part of the national lexicon, but is often a source of confusion by those not familiar with flood science and statistics. This poster is an attempt to explain the concept, probabilistic nature, and inherent uncertainties of the '100-year flood' to the layman.

  20. [Sheehan's syndrome--a forgotten disease with 100 years' history].

    PubMed

    Krysiak, Robert; Okopień, Bogusław

    2015-01-01

    Although named after Harold Sheehan, postpartum ischemic pituitary necrosis was reported for the first time 100 years ago in Przeglad Lekarski by Leon Konrad Gliński. In the majority of cases, the syndrome is a consequence of severe postpartum bleeding episode resulting in severe hypotension or hemorrhagic shock. The frequency of Sheehan's syndrome has decreased in developed countries as a result of improved obstetrical care, but this clinical entity remains a common cause of hypopituitarism in developing countries. The syndrome is characterized by varying degrees of anterior pituitary dysfunction resulting from the deficiency of multiple pituitary hormones. The order of frequency of hormone loss has generally been found to be growth hormone and prolactin, gonadotropins, ACTH and thyrotropin. Women with Sheehan's syndrome exhibit a variety of signs and symptoms including failure to lactate or resume menses, loss of genital and axillary hair, and often occurring long after delivery clinical manifestations of central hypothyroidism and secondary adrenal insufficiency. Diagnosis is based on laboratory studies, including hormone levels and hormone stimulation tests. Treatment of Sheehan's syndrome involves hormone replacement therapy. The aim of this study is to review current knowledge on clinically relevant aspects of this clinical entity and to provide the reader with recommendations concerning its diagnosis and treatment.

  1. [The 20th century: 100 years of misfortune and splendor].

    PubMed

    Urdaneta-Carruyo, Eliéxer

    2005-01-01

    The 20th century has been one of the most intense and convulsive periods in the History of humanity. A century of paradoxes and contrasts, it began with optimism, it witnessed the apocalypse of two world wars, and finished with unimaginable scientific progress that gave us a new civilization that we cannot yet grasp. In this century, significant events happened that shaped our time and projected their results toward an immediate future. Some of these were providential in understanding man's life, fighting against illnesses and prolonging life, and others were of undeniable social importance for humanity. Some knowledge was based on the work of others. Philosophy was embedded in mathematics, as was science in philosophy, while politics and the economy exercised so decisive an influence in our way of feeling and living that culture and society were affected to the core. Within that century the biggest technological revolution of all the time was also created, as transcendent as it was unimaginable, which put mankind on the road to the stars with the moon landing and in the process created the information society whose signature symbol, the internet, emerged as a new demiurge. However, the 20th century, with all its misfortune and splendor, paradoxes and contrasts, creation and destruction, was the most transcendent in the whole of history and it bequeaths to the future a promising horizon in the search for a renovated meaning of life and a yearning for peaceful coexistence for the whole humanity.

  2. 100 Years of Commitment to Children: Change and Continuity.

    ERIC Educational Resources Information Center

    Shore, Rima

    The Foundation for Child Development (FCD) is the oldest philanthropy in the nation focused on improving the life prospects of children. This booklet, produced for FCD's centennial, describes the organization's origins and changes during the past 100 years. The booklet's sections, which include photographs, quotes, and a timeline, are: (1)…

  3. Centennial Calendar- 100 Years of the American Phytopathological Society

    Technology Transfer Automated Retrieval System (TEKTRAN)

    I edited a 40-page publication (calendar) that covered 18 chapters written by members of our society. This covered pioneering researchers, departments, and epidemics of the last 100 years of plant pathology in the U. S. This was given to all members of the American Phytopathological Society who att...

  4. Spring wheat gliadins: Have they changed in 100 years?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There have been many hard red spring (HRS) wheat cultivars released in North Dakota during the last 100 years. These cultivars have been improved for various characteristics such as, adaptation to weather conditions, high yield, and good milling and baking quality. The objectives of this study wer...

  5. Women in July Fourth Cartoons: A 100-Year Look.

    ERIC Educational Resources Information Center

    Meyer, Katherine; And Others

    1980-01-01

    Analyzes the dominance, appearance, and role of women as depicted in newspaper Independence Day political cartoons over a 100-year period. Concludes that woman's place has gradually broadened to include activities beyond wife and mother. Indicates a resistance to changing norms and difficulty in coping with emerging ones. (JMF)

  6. 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.

  7. 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.

  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. NASA Administrator Dan Goldin greets 100-year-old VIP.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Among the VIPs attending the launch of STS-99 is Captain Ralph Charles (left), standing next to NASA Administrator Dan Goldin. Charles hopes to have his wish fulfilled of watching a Shuttle launch in person. The 100-year-old aviator has experienced nearly a century of flight history, from the Wright Brothers to the Space Program. He took flying lessons from one of the first fliers trained by Orville Wright, first repaired then built airplanes, went barnstorming, operated a charter service in the Caribbean, and worked as a test pilot for the Curtiss Wright Airplane Co. Charles is the oldest licensed pilot in the United States, and is still flying.

  10. Palama Settlement: 100 years of serving a neighborhood's needs.

    PubMed

    Rath, P

    1995-11-01

    The founding of Palama Settlement brought to those who might not be able to afford it public health nurses for maternal care and nutrition, well-baby clinics, tuberculosis clinics, medical and dental clinics, and eventually major support of medical needs during and after the attack on Pearl Harbor. Palama Settlement celebrates its centennial year with many of its early functions assumed by state and private organizations, but it is prepared to enter the next 100 years of service to the community. Palama was founded by James Arthur Rath with the purpose of serving the community; many people today remember their childhood and Palama Settlement.

  11. Progress of Cometary Science in the Past 100 Years

    NASA Technical Reports Server (NTRS)

    Sekanina, Zdenek

    1999-01-01

    Enormous strides made by cometary science during the 20th century defy any meaningful comparison of its state 100 years ago and now. The great majority of the subfields enjoying much attention nowadays did not exist in the year 1900. Dramatic developments, especially in the past 30-50 years, have equally affected observational and theoretical studies of comets. The profound diversification of observing techniques has been documented by the ever widening limits on the electromagnetic spectrum covered. While the time around 1900 marked an early period of slow and painful experimentation with photographic methods in cometary studies, observations of comets from the x-ray region to the radio waves have by now become routine. Many of the new techniques, and all those involved with the wavelengths shorter than about 300 nm, were made possible by another major breakthrough of this century - observing from space. Experiments on dedicated Earth-orbiting satellites as well as several deep-space probes have provided fascinating new information on the nature and makeup of comets. In broader terms, much of the progress has been achieved thanks to fundamental discoveries and major advances in electronics, whose applications resulted in qualitatively new instruments (e.g. radiotelescopes) and sensors or detectors (e.g. CCD arrays). The most universal effect on the entire cometary science, from observing to data handling to quantitative interpretations, has been, as in any other branch of science, due to the introduction of electronic computers, with their processing capabilities not only unheard of, but literally unimaginable, in the age of classical desk calculators. As if all this should not be enough, the today's generations of comet scientists have, in addition, been blessed with nature's highly appreciated cooperation. Indeed, in the span of a dozen years, between 1985 and 1997, we were privileged to witness four remarkable cometary events: (i) a return of Halley

  12. A Tale of 3 P's--Penmanship, Product, and Process: 100 Years of Elementary Writing Instruction

    ERIC Educational Resources Information Center

    Hawkins, Lisa K.; Razali, Abu Bakar

    2012-01-01

    From penmanship, to product, to process...this article recounts 100 years of instructional practice in the US elementary writing classroom through the voices of past teaching manuals and curriculum guides. This particular tale begins at the turn of the 20th century--a time when the elementary school was firmly established in the country, and…

  13. FUSE Observations of Jovian Aurora at the Time of the New Horizons Flyby

    NASA Astrophysics Data System (ADS)

    Feldman, P. D.; Weaver, H. A.; Retherford, K. D.; Gladstone, G. R.; Strobel, D. F.; Stern, S. A.

    2008-12-01

    At the time of the New Horizons flyby of Jupiter on 28 February 2007, there was a five-day window of opportunity during which the Far Ultraviolet Spectroscopic Explorer (FUSE), despite the loss of three of its four reaction wheels, could be stably pointed at Jupiter's position on the sky. FUSE was an orbiting spectroscopic observatory capable of spectral resolution better than 0.4~Å for extended sources in the wavelength range 905--1187~Å, together with very high sensitivity to weak emissions. Three orbits of observations were obtained in a point-and-stare mode beginning at 16:50 UT on 02 March 2007 of which for the first two the FUSE 30" × 30" aperture was centered on the north polar aurora. During each orbit the count rate was constant with time indicating that the target remained fully in the aperture during the entire exposure. These spectra will be compared with those obtained by FUSE in October 2000, December 2000, and January 2001, in terms of FUV luminosity and derived H2 vibrational population. We will also place these data in the context of the ultraviolet images obtained by the Hubble Space Telescope one Jovian rotation before and one after the FUSE observations.

  14. ''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.

  15. NASA Administrator Dan Goldin greets 100-year-old VIP.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Astronaut Andy Thomas (left) greets 100-year-old Captain Ralph Charles, one of the VIPs attending the launch of STS-99. Charles also met NASA Administrator Dan Goldin. An aviator who has the distinction of being the oldest licensed pilot in the United States, Charles is still flying. He has experienced nearly a century of flight history, from the Wright Brothers to the Space Program. He took flying lessons from one of the first fliers trained by Orville Wright, first repaired then built airplanes, went barnstorming, operated a charter service in the Caribbean, and worked as a test pilot for the Curtiss Wright Airplane Co. Charles watches all the Shuttle launches from his home in Ohio and his greatest wish is to be able to watch one in person from KSC.

  16. 100 years after Smoluchowski: stochastic processes in cell biology

    NASA Astrophysics Data System (ADS)

    Holcman, D.; Schuss, Z.

    2017-03-01

    100 years after Smoluchowski introduced his approach to stochastic processes, they are now at the basis of mathematical and physical modeling in cellular biology: they are used for example to analyse and to extract features from a large number (tens of thousands) of single molecular trajectories or to study the diffusive motion of molecules, proteins or receptors. Stochastic modeling is a new step in large data analysis that serves extracting cell biology concepts. We review here Smoluchowski’s approach to stochastic processes and provide several applications for coarse-graining diffusion, studying polymer models for understanding nuclear organization and finally, we discuss the stochastic jump dynamics of telomeres across cell division and stochastic gene regulation.

  17. 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.

  18. Time horizon dependent characterization factors for acidification in life-cycle assessment based on forest plant species occurrence in Europe

    SciTech Connect

    Rosalie van Zelm; Mark A.J. Huijbregts; Hans A. van Jaarsveld; Gert Jan Reinds; Dick de Zwart; Jaap Struijs; Dik van de Meent

    2007-02-15

    This paper describes a new approach in life-cycle impact assessment to derive characterization factors for acidification in European forests. Time horizon dependent characterization factors for acidification were calculated, whereas before only steady-state factors were available. The characterization factors indicate the change in the potential occurrence of plant species due to a change in emission, and they consist of a fate and an effect factor. The fate factor combines the results of an atmospheric deposition model and a dynamic soil acidification model. The change in base saturation in soil due to an atmospheric emission change was derived for 20, 50, 100, and 500 year time horizons. The effect factor was based on a dose-response curve of the potential occurrence of plant species, derived from multiple regression equations per plant species. The results showed that characterization factors for acidification increase up to a factor of 13 from a 20 years to a 500 years time horizon. Characterization factors for ammonia are 4.0-4.3 times greater than those for nitrogen oxides (NOx), and characterization factors for sulfur dioxide are 1.4-2.0 times greater than those for NOx. Aggregation of damage due to acidification with other impact categories on the European scale becomes feasible with the applied approach. 45 refs., 3 figs., 1 tab.

  19. Time horizon dependent characterization factors for acidification in life-cycle assessment based on forest plant species occurrence in Europe.

    PubMed

    Van Zelm, Rosalie; Huijbregts, Mark A J; van Jaarsveld, Hans A; Reinds, Gert Jan; de Zwart, Dick; Struijs, Jaap; van de Meent, Dik

    2007-02-01

    This paper describes a new approach in life-cycle impact assessment to derive characterization factors for acidification in European forests. Time horizon dependent characterization factors for acidification were calculated, whereas before only steady-state factors were available. The characterization factors indicate the change in the potential occurrence of plant species due to a change in emission, and they consist of a fate and an effect factor. The fate factor combines the results of an atmospheric deposition model and a dynamic soil acidification model. The change in base saturation in soil due to an atmospheric emission change was derived for 20, 50, 100, and 500 year time horizons. The effect factor was based on a dose-response curve of the potential occurrence of plant species, derived from multiple regression equations per plant species. The results showed that characterization factors for acidification increase up to a factor of 13 from a 20 years to a 500 years time horizon. Characterization factors for ammonia are 4.0-4.3 times greater than those for nitrogen oxides (NO(x)), and characterization factors for sulfur dioxide are 1.4-2.0 times greater than those for NO(x). Aggregation of damage due to acidification with other impact categories on the European scale becomes feasible with the applied approach.

  20. Slope restoration for a 100-year old canal

    SciTech Connect

    Skaggs, R.L.; Lewis, S.W.; Liebersbach, D.C.

    1995-12-31

    Turlock Irrigation District (TID) is located in the northern portion of the fertile San Joaquin Valley of California. TID`s primary water supply is conveyed from the 100-year-old LaGrange Diversion Dam via their historic Upper Main Canal. The original canal was constructed by excavating into slate bedrock for the uphill (cut) bank, and constructing unmortared rock walls and rock fill for the downhill (fill) embankment; the excavation was then lined with concrete. Soil fill raises of the downhill embankment over the last 30 years have reduced the slope stability to unacceptable levels in the steepest embankment areas. In March of 1994, two surficial slides prompted investigation of the long term embankment stability in the Warehouse Slide Area. Based on results of analysis for various stabilization scenarios, TID chose a stabilization method which included: (1) excavation of an access bench below the existing canal, (2) installation of steel pipe piles through the existing rock fill and into the bedrock, (3) construction of a mechanically stabilized earth (MSE) retaining wall and (4) construction of a soil-cement canal roadway pavement. The design was chosen by the owner because of cost competitiveness compared to other design alternatives and because the construction sequence allowed uninterrupted use of the canal. By using local river cobble for the MSE wall facing material, TID met the desired 50-year design life of the repair while maintaining the area`s historic visual features.

  1. Colloquium: 100 years of mass spectrometry: Perspectives and future trends

    NASA Astrophysics Data System (ADS)

    Maher, Simon; Jjunju, Fred P. M.; Taylor, Stephen

    2015-01-01

    Mass spectrometry (MS) is widely regarded as the most sensitive and specific general purpose analytical technique. More than a century has passed for MS since the ground-breaking work of Nobel laureate Sir Joseph John Thomson in 1913. This Colloquium aims to (1) give an historical overview of the major instrumentation achievements that have driven mass spectrometry forward in the past century, including those leading up to the initial work of Thomson, (2) provide the nonspecialist with an introduction to MS, and (3) highlight some key applications of MS and explore the current and future trends. Because of the vastness of the subject area and quality of the manifold research efforts that have been undertaken over the last 100 years, which have contributed to the foundations and subsequent advances in mass spectrometry, it should be understood that not all of the key contributions may have been included in this Colloquium. Mass spectrometry has embraced a multitude of scientific disciplines and to recognize all of the achievements is an impossible task, such has been the diverse impact of this invaluable technique. Scientific progress is usually made via the cumulative effort of a large number of researchers; the achievements reported herein are only a representation of that effort.

  2. Pedernales oilfield, eastern Venezuela: The first 100 years

    SciTech Connect

    Gluyas, J.; Oliver, J.; Wilson, W.

    1996-08-01

    Petroleum seeps and surface tar mats attracted oil explorers to Pedernales in eastern Venezuela 100 years ago. Commercial production from the Pedernales Field was established by Creole in 1933. In three production periods, broken by WWII and the end of the Creole-Texaco refining contract, Creole and Lagoven produced about 60 MMSTB from about 60 wells in about 60 years. Peak production was in the late 1950s, when the field delivered 12,000 BOPD. Production was stopped in 1986. In March 1993, BP Venezuela acquired the license to reactivate Pedernales on behalf of Lagoven, and BP`s first well in the field was drilled in August 1994. A second was completed in early 1995. The production from each well was sufficiently encouraging for commerciality to be declared in March 1995. Phase 1 of the field reactivation demanded a production rate of 11,500 BOPD. As of now (September, 1995) six wells, including one gas disposal well, have been completed. Wells have been placed using a combination of old well data and mapping based on a close spaced 2D seismic survey shot in early 1994. Results from these first few wells indicate that the required production rate will be achieved despite severely depleted reservoir pressures. This paper tells the story of reactivation and re-evaluation of one of eastern Venezuela`s oldest oilfields.

  3. Decision Modeling in Sleep Apnea: The Critical Roles of Pretest Probability, Cost of Untreated Obstructive Sleep Apnea, and Time Horizon

    PubMed Central

    Moro, Marilyn; Westover, M. Brandon; Kelly, Jessica; Bianchi, Matt T.

    2016-01-01

    Study Objectives: Obstructive sleep apnea (OSA) is associated with increased morbidity and mortality, and treatment with positive airway pressure (PAP) is cost-effective. However, the optimal diagnostic strategy remains a subject of debate. Prior modeling studies have not consistently supported the widely held assumption that home sleep testing (HST) is cost-effective. Methods: We modeled four strategies: (1) treat no one; (2) treat everyone empirically; (3) treat those testing positive during in-laboratory polysomnography (PSG) via in-laboratory titration; and (4) treat those testing positive during HST with auto-PAP. The population was assumed to lack independent reasons for in-laboratory PSG (such as insomnia, periodic limb movements in sleep, complex apnea). We considered the third-party payer perspective, via both standard (quality-adjusted) and pure cost methods. Results: The preferred strategy depended on three key factors: pretest probability of OSA, cost of untreated OSA, and time horizon. At low prevalence and low cost of untreated OSA, the treat no one strategy was favored, whereas empiric treatment was favored for high prevalence and high cost of untreated OSA. In-laboratory backup for failures in the at-home strategy increased the preference for the at-home strategy. Without laboratory backup in the at-home arm, the in-laboratory strategy was increasingly preferred at longer time horizons. Conclusion: Using a model framework that captures a broad range of clinical possibilities, the optimal diagnostic approach to uncomplicated OSA depends on pretest probability, cost of untreated OSA, and time horizon. Estimating each of these critical factors remains a challenge warranting further investigation. Citation: Moro M, Westover MB, Kelly J, Bianchi MT. Decision modeling in sleep apnea: the critical roles of pretest probability, cost of untreated obstructive sleep apnea, and time horizon. J Clin Sleep Med 2016;12(3):409–418. PMID:26518699

  4. Virasoro algebra with central charge c=1 on the horizon of a two-dimensional-Rindler space-time

    NASA Astrophysics Data System (ADS)

    Moretti, Valter; Pinamonti, Nicola

    2004-01-01

    Using the holographic machinery built up in a previous work, we show that the hidden SL(2,R) symmetry of a scalar quantum field propagating in a Rindler space-time admits an enlargement in terms of a unitary positive-energy representation of Virasoro algebra defined in the Fock representation. That representation has central charge c=1. The Virasoro algebra of operators gets a manifest geometrical meaning if referring to the holographically associated quantum field theory on the horizon: It is nothing but a representation of the algebra of vector fields defined on the horizon equipped with a point at infinity. All that happens provided the Virasoro ground energy h≔μ2/2 vanishes and, in that case, the Rindler Hamiltonian is associated with a certain Virasoro generator. If a suitable regularization procedure is employed, for h=1/2, the ground state of that generator seems to correspond to a thermal state when examined in the Rindler wedge, taking the expectation value with respect to Rindler time. Finally, under Wick rotation in Rindler time, the pair of quantum field theories which are built up on the future and past horizon defines a proper two-dimensional conformal quantum field theory on a cylinder.

  5. 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.

  6. 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

  7. 100 Years of Radiation Research in the Footsteps of Failla.

    PubMed

    Hall, Eric J

    2017-01-31

    Gioacchino Failla was initially appointed to operate the radon plant at Memorial Hospital in 1916. What to most people would have been a part-time temporary position was to him a career. He was not satisfied to simply fabricate radon seeds, he wanted to understand the physics and biology of the radiation emitted by the progeny of radium. His was not the first medical physics group in the United States, though it was one of the earliest, but it was the first to put such emphasis on the biological effects. After more than 28 years at Memorial Hospital, Failla moved his research group to Columbia University Medical Center and his pioneering work, blending physics and biology, has continued to date at Columbia by those that he trained or inspired, under three directors that followed him.

  8. Detection of runaway electrons - a journey 100 years long

    NASA Astrophysics Data System (ADS)

    Chilingarian, Ashot

    2013-04-01

    of the scintillators allow detect CES on Aragats and for the first time prove existence of RREA phenomena.

  9. Nigeria Anopheles Vector Database: An Overview of 100 Years' Research

    PubMed Central

    Okorie, Patricia Nkem; McKenzie, F. Ellis; Ademowo, Olusegun George; Bockarie, Moses; Kelly-Hope, Louise

    2011-01-01

    Anopheles mosquitoes are important vectors of malaria and lymphatic filariasis (LF), which are major public health diseases in Nigeria. Malaria is caused by infection with a protozoan parasite of the genus Plasmodium and LF by the parasitic worm Wuchereria bancrofti. Updating our knowledge of the Anopheles species is vital in planning and implementing evidence based vector control programs. To present a comprehensive report on the spatial distribution and composition of these vectors, all published data available were collated into a database. Details recorded for each source were the locality, latitude/longitude, time/period of study, species, abundance, sampling/collection methods, morphological and molecular species identification methods, insecticide resistance status, including evidence of the kdr allele, and P. falciparum sporozoite rate and W. bancrofti microfilaria prevalence. This collation resulted in a total of 110 publications, encompassing 484,747 Anopheles mosquitoes in 632 spatially unique descriptions at 142 georeferenced locations being identified across Nigeria from 1900 to 2010. Overall, the highest number of vector species reported included An. gambiae complex (65.2%), An. funestus complex (17.3%), An. gambiae s.s. (6.5%). An. arabiensis (5.0%) and An. funestus s.s. (2.5%), with the molecular forms An. gambiae M and S identified at 120 locations. A variety of sampling/collection and species identification methods were used with an increase in molecular techniques in recent decades. Insecticide resistance to pyrethroids and organochlorines was found in the main Anopheles species across 45 locations. Presence of P. falciparum and W. bancrofti varied between species with the highest sporozoite rates found in An. gambiae s.s, An. funestus s.s. and An. moucheti, and the highest microfilaria prevalence in An. gambiae s.l., An. arabiensis, and An. gambiae s.s. This comprehensive geo-referenced database provides an essential baseline on Anopheles

  10. 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.

  11. Global change and water resources in the next 100 years

    NASA Astrophysics Data System (ADS)

    Larsen, M. C.; Hirsch, R. M.

    2010-03-01

    We are in the midst of a continental-scale, multi-year experiment in the United States, in which we have not defined our testable hypotheses or set the duration and scope of the experiment, which poses major water-resources challenges for the 21st century. What are we doing? We are expanding population at three times the national growth rate in our most water-scarce region, the southwestern United States, where water stress is already great and modeling predicts decreased streamflow by the middle of this century. We are expanding irrigated agriculture from the west into the east, particularly to the southeastern states, where increased competition for ground and surface water has urban, agricultural, and environmental interests at odds, and increasingly, in court. We are expanding our consumption of pharmaceutical and personal care products to historic high levels and disposing them in surface and groundwater, through sewage treatment plants and individual septic systems. These substances are now detectable at very low concentrations and we have documented significant effects on aquatic species, particularly on fish reproduction function. We don’t yet know what effects on human health may emerge, nor do we know if we need to make large investments in water treatment systems, which were not designed to remove these substances. These are a few examples of our national-scale experiment. In addition to these water resources challenges, over which we have some control, climate change models indicate that precipitation and streamflow patterns will change in coming decades, with western mid-latitude North America generally drier. We have already documented trends in more rain and less snow in western mountains. This has large implications for water supply and storage, and groundwater recharge. We have documented earlier snowmelt peak spring runoff in northeastern and northwestern States, and western montane regions. Peak runoff is now about two weeks earlier than it was

  12. Morphological response of songbirds to 100 years of landscape change in North America.

    PubMed

    Desrochers, A

    2010-06-01

    Major landscape changes caused by humans may create strong selection pressures and induce rapid evolution in natural populations. In the last 100 years, eastern North America has experienced extensive clear-cutting in boreal areas, while afforestation has occurred in most temperate areas. Based on museum specimens, I show that wings of several boreal forest songbirds and temperate songbirds of non-forest habitats have become more pointed over the last 100 years. In contrast, wings of most temperate forest and early-successional boreal forests species have become less pointed over the same period. In contrast to wing shape, the bill length of most species did not change significantly through time. These results are consistent with the "habitat isolation hypothesis", i.e., songbirds evolved in response to recent changes in the amount of available habitat and associated implications for mobility. Rapid morphological evolution may mitigate, without necessarily preventing, negative consequences of habitat loss caused by humans through direct exploitation or climate change.

  13. Solving the Supreme Problem: 100 years of selection and recruitment at the Journal of Applied Psychology.

    PubMed

    Ployhart, Robert E; Schmitt, Neal; Tippins, Nancy T

    2017-03-01

    This article reviews 100 years of research on recruitment and selection published in the Journal of Applied Psychology. Recruitment and selection research has been present in the Journal from the very first issue, where Hall (1917) suggested that the challenge of recruitment and selection was the Supreme Problem facing the field of applied psychology. As this article shows, the various topics related to recruitment and selection have ebbed and flowed over the years in response to business, legal, and societal changes, but this Supreme Problem has captivated the attention of scientist-practitioners for a century. Our review starts by identifying the practical challenges and macro forces that shaped the sciences of recruitment and selection and helped to define the research questions the field has addressed. We then describe the evolution of recruitment and selection research and the ways the resulting scientific advancements have contributed to staffing practices. We conclude with speculations on how recruitment and selection research may proceed in the future. Supplemental material posted online provides additional depth by including a summary of practice challenges and scientific advancements that affected the direction of selection and recruitment research and an outline of seminal articles published in the Journal and corresponding time line. The 100-year anniversary of the Journal of Applied Psychology is very much the celebration of recruitment and selection research, although predictions about the future suggest there is still much exciting work to be done. (PsycINFO Database Record

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

    SciTech Connect

    Ganguly, Auroop R.; Ganguli, Poulomi; Kumar, Devashish

    2014-09-01

    Thermoelectric power production at risk, owing to current and projected water scarcity and rising stream temperatures, is assessed for the contiguous United States 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 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 risk 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. Our analyses showed that in the near term, more than 200 counties are likely to be exposed to water scarcity in the next three decades. Further, we noticed that stream gauges in more than five counties in the 2030s and ten counties in the 2040s showed a significant increase in water temperature, which exceeded the power plant effluent temperature threshold set by the EPA. Power plants in South Carolina, Louisiana, and Texas are likely to be vulnerable owing to climate driven water stresses. In all, our analysis suggests that under various combinations of plausible climate

  15. High-Resolution Over-the-Horizon Radar Using Time Reversal

    DTIC Science & Technology

    2009-12-07

    successfully demonstrated in acoustics [3-7]. However, the implementation of time reversal in the microwave domain has been impeded by the lack of...of imaging method has been known using time reversal. Most of the time reversal methods proposed to date are mainly intended for retro-directive...beam focusing on a target for tracking. Although several decomposition methods have been developed for some imaging applications, they normally require

  16. 100 years of applied psychology research on individual careers: From career management to retirement.

    PubMed

    Wang, Mo; Wanberg, Connie R

    2017-03-01

    This article surveys 100 years of research on career management and retirement, with a primary focus on work published in the Journal of Applied Psychology. Research on career management took off in the 1920s, with most attention devoted to the development and validation of career interest inventories. Over time, research expanded to attend to broader issues such as the predictors and outcomes of career interests and choice; the nature of career success and who achieves it; career transitions and adaptability to change; retirement decision making and adjustment; and bridge employment. In this article, we provide a timeline for the evolution of the career management and retirement literature, review major theoretical perspectives and findings on career management and retirement, and discuss important future research directions. (PsycINFO Database Record

  17. From Anzac to Afghanistan: have 100 years taught us nothing about the devastation of war?

    PubMed

    Carragee, Eugene J

    2015-12-01

    Commentary On: Atkinson Brigadier (Ret'd) RN, Fraser RD. 100 years-Anzac, Vietnam to now. Spine J 2015:15:2454-6 (in this issue). Robertson PA. Gallipoli 100 years on: a New Zealand perspective. Spine J 2015:15:2457-8 (in this issue).

  18. 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.

  19. 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.

  20. 100+ years of instrumental seismology: the example of the ISC-GEM Global Earthquake Instrumental Catalogue

    NASA Astrophysics Data System (ADS)

    Storchak, Dmitry; Di Giacomo, Domenico

    2015-04-01

    Systematic seismological observations of earthquakes using seismic instruments on a global scale began more than 100 years ago. Since then seismologists made many discoveries about the Earth interior and the physics of the earthquakes, also thanks to major developments in the seismic instrumentation deployed around the world. Besides, since the establishment of the first global networks (Milne and Jesuit networks), seismologists around the world stored and exchanged the results of routine observations (e.g., picking of arrival times, amplitude-period measurements, etc.) or more sophisticated analyses (e.g., moment tensor inversion) in seismological bulletins/catalogues. With a project funded by the GEM Foundation (www.globalquakemodel.org), the ISC and the Team of International Experts released a new global earthquake catalogue, the ISC-GEM Global Instrumental Earthquake Catalogue (1900 2009) (www.isc.ac.uk/iscgem/index.php), which, differently from previous global seismic catalogues, has the unique feature of covering the entire period of instrumental seismology with locations and magnitude re-assessed using modern approaches for the global earthquakes selected for processing (in the current version approximately 21,000). During the 110 years covered by the ISC-GEM catalogue many seismological developments occurred in terms of instrumentation, seismological practice and knowledge of the physics of the earthquakes. In this contribution we give a brief overview of the major milestones characterizing the last 100+ years of instrumental seismology that were relevant for the production of the ISC-GEM catalogue and the major challenges we faced to obtain a catalogue as homogenous as possible.

  1. 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.

  2. 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*.

  3. 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.

  4. 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.

  5. 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.

  6. Investigation of horizon Beta.

    PubMed

    Windisch, C C; Leyden, R J; Worzel, J L; Saito, T; Ewing, J

    1968-12-27

    Horizon beta is a subbottom reflector in the North Atlantic deep ocean sediments that extends over a large portion of the North America basin. Cores from an outcrop of beta contained shallow-water Aptian-Albian sediments and deep-water Cenomanian sediments. A core near an outcrop of a deeper horizon, horizon B, contained shallow-water Lower Cretaceous (Barremian-Hauterivian) sediments. These cores can be interpreted to support extensive subsidence of the eastern portion of the basin in early Cretaceous time. It is equally likely that the shallow-water deposits are a result of sediments slumping into an already deep basin. A reconciliation of these interpretations depends upon the JOIDES project.

  7. 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.

  8. Base (100-year) flood elevations for selected sites in Livingston County, Missouri

    USGS Publications Warehouse

    Southard, Rodney E.; Richards, Joseph M.

    2002-01-01

    The primary criteria for community participation in the National Flood Insurance Program is the adoption and enforcement of floodplain management requirements that minimize the potential for flood damages to existing and proposed development in flood-hazard areas. This report provides base flood elevations (BFE) for a 100-year recurrence-interval flood for use in the management and regulation of 18 flood-hazard areas designated by the Federal Emergency Management Agency as approximate Zone A areas in Livingston County, Missouri. The one-dimensional surface-water flow models HEC-RAS and Water-Surface PROfile (WSPRO) were used to compute base (100-year) flood elevations for 18 Zone A sites. The HEC-RAS model was used at BFE sites 1 to 6, 9, 10, and 15 to 18. The WSPRO model was used at BFE sites 7, 8, and 11 to 14. The 18 sites are all located in Livingston County, Missouri, at U.S., State, or County road crossings, and the base flood elevation was determined at the upstream side of each crossing. The base (100-year) flood elevations for BFE 1, 2, and 3 on Shoal Creek at Dawn and Shoal Creek Drainage Ditch near Dawn are 701.0, 701.0, and 696.5 feet, respectively. The base (100-year) flood elevations for BFE 4 and 5 on Indian Branch near Sampsel and a tributary to Indian Branch near Sampsel are 711.7 and 755.4 feet, respectively. Site BFE 6 is located on Honey Creek near Farmersville and the base (100-year) flood elevation for this site is 730.8 feet. One site (BFE 7) is located on No Creek near Farmersville. The base (100-year) flood elevation for this site is 731.3 feet. Site BFE 8 is located on Crooked Creek near Chillicothe and the base (100-year) elevation is 716.4 feet. One site (BFE 9) is located on a tributary to Coon Creek at Chillicothe. The base (100-year) flood elevation for this site is 734.9 feet. Two sites (BFE 10 and 11) are located on Blackwell Branch at Chillicothe. The base (100-year) flood elevation for BFE 10 is 738.9 feet and for BFE 11 is 701

  9. Dynamic optimization over infinite-time horizon: web-building strategy in an orb-weaving spider as a case study.

    PubMed

    Venner, Samuel; Chadès, Iadine; Bel-Venner, Marie-Claude; Pasquet, Alain; Charpillet, François; Leborgne, Raymond

    2006-08-21

    Dynamic state-dependent models have been widely developed since 1990s for solving questions in evolutionary ecology. Up to now, these models were mainly run over finite-time horizon. However, for many biological questions an infinite-time horizon perspective could be more appropriate, especially when the end of the modeled period is state- rather than time-dependent. Despite this approach is widely used in the field of economics and operational research, thus far no work has been providing biologists with a general method to solve infinite-time horizon problems. Here we present such a method, through the exhaustive description of an algorithm that we implement to determine the strategy an organism should follow to reach a particular state as fast as possible while limiting mortality risk. To illustrate that method we explored web-building behavior in an orb-weaving spider. How are adult females predicted to build their successive webs to gain energy, grow, and lay their first clutch as fast as possible, without suffering from either predation or starvation? From this example, we first show how an optimal strategy over infinite-time horizon can be processed and selected. Second, we analyse variations of the optimal web-building strategy along with the spider's body weight and predation risk during web building. Our model yields two main predictions: (1) spiders reduce their web size as they are gaining weight due to body-mass-dependent cost of web-building behavior, and (2) this reduction in web size starts at lower weight under higher predation risk.

  10. 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

  11. Base (100-year) flood elevations for selected sites in Marion County, Missouri

    USGS Publications Warehouse

    Southard, Rodney E.; Wilson, Gary L.

    1998-01-01

    The primary requirement for community participation in the National Flood Insurance Program is the adoption and enforcement of floodplain management requirements that minimize the potential for flood damages to new construction and avoid aggravating existing flooding conditions. This report provides base flood elevations (BFE) for a 100-year recurrence flood for use in the management and regulation of 14 flood-hazard areas designated by the Federal Emergency Management Agency as approximate Zone A areas in Marion County, Missouri. The one-dimensional surface-water flow model, HEC-RAS, was used to compute the base (100-year) flood elevations for the 14 Zone A sites. The 14 sites were located at U.S., State, or County road crossings and the base flood elevation was determined at the upstream side of each crossing. The base (100-year) flood elevations for BFE 1, 2, and 3 on the South Fork North River near Monroe City, Missouri, are 627.7, 579.2, and 545.9 feet above sea level. The base (100-year) flood elevations for BFE 4, 5, 6, and 7 on the main stem of the North River near or at Philadelphia and Palmyra, Missouri, are 560.5, 539.7, 504.2, and 494.4 feet above sea level. BFE 8 is located on Big Branch near Philadelphia, a tributary to the North River, and the base (100-year) flood elevation at this site is 530.5 feet above sea level. One site (BFE 9) is located on the South River near Monroe City, Missouri. The base (100-year) flood elevation at this site is 619.1 feet above sea level. Site BFE 10 is located on Bear Creek near Hannibal, Missouri, and the base (100-year) elevation is 565.5 feet above sea level. The four remaining sites (BFE 11, 12, 13, and 14) are located on the South Fabius River near Philadelphia and Palmyra, Missouri. The base (100-year) flood elevations for BFE 11, 12, 13, and 14 are 591.2, 578.4, 538.7, and 506.9 feet above sea level.

  12. Discharge, gage height, and elevation of 100-year floods in the Hudson River basin, New York

    USGS Publications Warehouse

    Archer, Roger J.

    1978-01-01

    The flood discharge that may be expected to be equaled or exceeded on the average of once in 100 years (100-year flood) was computed by the log-Pearson Type-III frequency relation for 72 stations in the Hudson River basin. These discharges and, where available, their corresponding gage height and elevation above mean sea level are presented in tabular form. A short explanation of computation methods is included. The data are to be used as part of a federally funded study of the water resources and related land resources of the Hudson River basin. (Woodard-USGS)

  13. 100 years of California’s water rights system: patterns, trends and uncertainty

    NASA Astrophysics Data System (ADS)

    Grantham, Theodore E.; Viers, Joshua H.

    2014-08-01

    For 100 years, California’s State Water Resources Control Board and its predecessors have been responsible for allocating available water supplies to beneficial uses, but inaccurate and incomplete accounting of water rights has made the state ill-equipped to satisfy growing societal demands for water supply reliability and healthy ecosystems. Here, we present the first comprehensive evaluation of appropriative water rights to identify where, and to what extent, water has been dedicated to human uses relative to natural supplies. The results show that water right allocations total 400 billion cubic meters, approximately five times the state’s mean annual runoff. In the state’s major river basins, water rights account for up to 1000% of natural surface water supplies, with the greatest degree of appropriation observed in tributaries to the Sacramento and San Joaquin Rivers and in coastal streams in southern California. Comparisons with water supplies and estimates of actual use indicate substantial uncertainty in how water rights are exercised. In arid regions such as California, over-allocation of surface water coupled with trends of decreasing supply suggest that new water demands will be met by re-allocation from existing uses. Without improvements to the water rights system, growing human and environmental demands portend an intensification of regional water scarcity and social conflict. California’s legal framework for managing its water resources is largely compatible with needed reforms, but additional public investment is required to enhance the capacity of the state’s water management institutions to effectively track and regulate water rights.

  14. The Archives of the Department of Terrestrial Magnetism: Documenting 100 Years of Carnegie Science

    NASA Astrophysics Data System (ADS)

    Hardy, S. J.

    2005-12-01

    The archives of the Department of Terrestrial Magnetism (DTM) of the Carnegie Institution of Washington document more than a century of geophysical and astronomical investigations. Primary source materials available for historical research include field and laboratory notebooks, equipment designs, plans for observatories and research vessels, scientists' correspondence, and thousands of expedition and instrument photographs. Yet despite its history, DTM long lacked a systematic approach to managing its documentary heritage. A preliminary records survey conducted in 2001 identified more than 1,000 linear feet of historically-valuable records languishing in dusty, poorly-accessible storerooms. Intellectual control at that time was minimal. With support from the National Historical Publications and Records Commission, the "Carnegie Legacy Project" was initiated in 2003 to preserve, organize, and facilitate access to DTM's archival records, as well as those of the Carnegie Institution's administrative headquarters and Geophysical Laboratory. Professional archivists were hired to process the 100-year backlog of records. Policies and procedures were established to ensure that all work conformed to national archival standards. Records were appraised, organized, and rehoused in acid-free containers, and finding aids were created for the project web site. Standardized descriptions of each collection were contributed to the WorldCat bibliographic database and the AIP International Catalog of Sources for History of Physics. Historic photographs and documents were digitized for online exhibitions to raise awareness of the archives among researchers and the general public. The success of the Legacy Project depended on collaboration between archivists, librarians, historians, data specialists, and scientists. This presentation will discuss key aspects (funding, staffing, preservation, access, outreach) of the Legacy Project and is aimed at personnel in observatories, research

  15. What Would You Look Like If You Were 100 Years Old?

    ERIC Educational Resources Information Center

    Petersen, Hugh

    1998-01-01

    Describes a project inspired by the 100th day of school in which first-grade students created a self-portrait of themselves at 100 years old and wrote an accompanying essay. States that the students drew wrinkles on the faces, age-appropriate clothing, gray or white hair, and even glasses as a finishing touch. (CMK)

  16. Assessment Gaze, Refraction, and Blur: The Course of Achievement Testing in the Past 100 Years

    ERIC Educational Resources Information Center

    Baker, Eva L.; Chung, Gregory K. W. K.; Cai, Li

    2016-01-01

    This chapter addresses assessment (testing) with an emphasis on the 100-year period since the American Education Research Association was formed. The authors start with definitions and explanations of contemporary tests. They then look backward into the 19th century to significant work by Horace Mann and Herbert Spencer, who engendered two…

  17. Behind the geon horizon

    NASA Astrophysics Data System (ADS)

    Guica, Monica; Ross, Simon F.

    2015-03-01

    We explore the Papadodimas-Raju prescription for reconstructing the region behind the horizon of one-sided black holes in AdS/CFT in the case of the {R}{{P}2} geon—a simple, analytic example of a single-sided, asymptotically AdS3 black hole, which corresponds to a pure CFT state that thermalizes at late times. We show that in this specific example, the mirror operators involved in the reconstruction of the interior have a particularly simple form: the mirror of a single trace operator at late times is just the corresponding single trace operator at early times. We use some explicit examples to explore how changes in the state modify the geometry inside the horizon.

  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. Ice core evidence for significant 100-year regional warming on the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Thomas, E. R.; Dennis, P. F.; Bracegirdle, T. J.; Franzke, C.

    2009-10-01

    We present a new 150-year, high-resolution, stable isotope record (δ 18O) from the Gomez ice core, drilled on the data sparse south western Antarctic Peninsula, revealing a ˜2.7°C rise in surface temperatures since the 1950s. The record is highly correlated with satellite-derived temperature reconstructions and instrumental records from Faraday station on the north west coast, thus making it a robust proxy for local and regional temperatures since the 1850s. We conclude that the exceptional 50-year warming, previously only observed in the northern Peninsula, is not just a local phenomena but part of a statistically significant 100-year regional warming trend that began around 1900. A suite of coupled climate models are employed to demonstrate that the 50 and 100 year temperature trends are outside of the expected range of variability from pre-industrial control runs, indicating that the warming is likely the result of external climate forcing.

  20. Areas subject to inundation by the 100-year flood in Avra Valley, Pima County, Arizona

    USGS Publications Warehouse

    Roeske, R.H.

    1978-01-01

    Avra Valley in Pima County, Arizona, is sparsely populated and is used mainly for agriculture and cattle grazing; however, its proximity to Tucson makes it desirable for urban development. Administrators and planners concerned with future land development may use the map report to determine the approximate areas that are subject to inundation by the 100-year flood. Avra Valley is drained mainly by Brawley Wash; Blanco Wash drains the west side of the valley. Most of the natural drainage system consists of small braided channels bordered by narrow bands of dense vegetation, which cause floodwater to spread over wide areas of shallow depths. During the 100-year flood, the areas inundated by Brawley and Blanco Washes may join in several places. (Woodard-USGS)

  1. Creating Long Term Income Streams for the 100 Year Starship Study Initiative

    NASA Astrophysics Data System (ADS)

    Sylvester, A. J.

    Development and execution of long term research projects are very dependent on a consistent application of funding to maximize the potential for success. The business structure for the 100 Year Starship Study project should allow for multiple income streams to cover the expenses of the research objectives. The following examples illustrate the range of potential avenues: 1) affiliation with a charitable foundation for creating a donation program to fund a long term endowment for research, 2) application for grants to fund initial research projects and establish the core expertise of the research entity, 3) development of intellectual property which can then be licensed for additional revenue, 4) creation of spinout companies with equity positions retained by the lab for funding the endowment, and 5) funded research which is dual use for the technology goals of the interstellar flight research objectives. With the establishment of a diversified stream of funding options, then the endowment can be funded at a level to permit dedicated research on the interstellar flight topics. This paper will focus on the strategy of creating spinout companies to create income streams which would fund the endowment of the 100 Year Starship Study effort. This technique is widely used by universities seeking to commercially develop and market technologies developed by university researchers. An approach will be outlined for applying this technique to potentially marketable technologies generated as a part of the 100 Year Starship Study effort.

  2. The Hunterian Neurosurgical Laboratory: the first 100 years of neurosurgical research.

    PubMed

    Sampath, P; Long, D M; Brem, H

    2000-01-01

    Modern neurosurgery has long had a strong laboratory foundation, and much of this tradition can be traced to the Hunterian Neurosurgical Laboratory of the Johns Hopkins Hospital. Founded with the basic goals of investigating the causes and symptoms of disease and establishing the crucial role that surgeons may play in the treatment of disease, the Hunterian laboratory has adhered to these tenets, despite the dramatic changes in neurosurgery that have occurred in the last 100 years. Named for the famous English surgeon John Hunter (1728-1793), the Hunterian laboratory was conceived by William Welch and William Halsted as a special laboratory for experimental work in surgery and pathology. In 1904, Harvey Cushing was appointed by Halsted to direct the laboratory. With the three primary goals of student education, veterinary surgery that stressed surgical techniques, and meticulous surgical and laboratory record-keeping, the laboratory was quite productive, introducing the use of physiological saline solutions, describing the anatomic features and function of the pituitary gland, and establishing the field of endocrinology. In addition, the original development of hanging drop tissue culture, fundamental investigations into cerebrospinal fluid, and countless contributions to otolaryngology by Samuel Crowe all occurred during this "crucible" period. In 1912, Cushing was succeeded by Walter Dandy, whose work on experimental hydrocephalus and cerebrospinal fluid circulation led to the development of pneumoencephalography. The early days of neurosurgery evolved with close ties to general surgery, and so did the Hunterian laboratory. After Dandy began devoting his time to clinical work, general surgeons (first Jay McLean and then, in 1922, Ferdinand Lee) became the directors of the laboratory. Between 1928 and 1942, more than 150 original articles were issued from the Hunterian laboratory; these articles described significant advances in surgery, including pioneering

  3. Spatio-temporal analysis of rainfall trends over a maritime state (Kerala) of India during the last 100 years

    NASA Astrophysics Data System (ADS)

    Nair, Archana; Ajith Joseph, K.; Nair, K. S.

    2014-05-01

    Kerala, a maritime state of India is bestowed with abundant rainfall which is about three times the national average. This study is conducted to have a better understanding of rainfall variability and trend at regional level for this state during the last 100 years. It is found that the rainfall variation in northern and southern regions of Kerala is large and the deviation is on different timescales. There is a shifting of rainfall mean and variability during the seasons. The trend analysis on rainfall data over the last 100 years reveals that there is a significant (99%) decreasing trend in most of the regions of Kerala especially in the month of January, July and November. The annual and seasonal trends of rainfall in most regions of Kerala are also found to be decreasing significantly. This decreasing trend may be related to global anomalies as a result of anthropogenic green house gas (GHG) emissions due to increased fossil fuel use, land-use change due to urbanisation and deforestation, proliferation in transportation associated atmospheric pollutants. We have also conducted a study of the seasonality index (SI) and found that only one district in the northern region (Kasaragod) has seasonality index of more than 1 and that the distribution of monthly rainfall in this district is mostly attributed to 1 or 2 months. In rest of the districts, the rainfall is markedly seasonal. The trend in SI reveals that the rainfall distribution in these districts has become asymmetric with changes in rainfall distribution.

  4. Observed climate variations during the last 100 years in Lapland, northern Finland

    NASA Astrophysics Data System (ADS)

    Lee, Susan E.; Press, M. C.; Lee, J. A.

    2000-03-01

    Many general circulation models (GCMs) predict that high latitude environments will experience substantial warming over the next 100 years, which will be particularly pronounced during the winter months. Precipitation is also expected to increase but there is uncertainty as to the amount and spatial variation.The flora and fauna of the arctic and subarctic regions, together with indigenous people, such as the Saami, are particularly vunerable to rising temperatures and changing precipitation. Mean monthly temperature and precipitation data were examined for the last 100 years for northern Finland. These data were further analysed for the first and second half of the 20th century.There was no discernible warming trend between 1876 and 1993, but a significant annual warming (r=0.344, <0.05) occurred in the period 1901-1945, together with a significant summer warming (r=0.381, ρ<0.05). Warming has occurred consistently in May and June over the last 100 years and there appears to be a current (i.e. post 1990) annual trend, mostly due to winter warming. The greatest temperature anomaly increase for the period 1901-1945 was in the winter months (+0.72°C). The degree of temperature variation in the winter is greater than in the summer and has risen from 3.98°C for December in the period 1901-1945 to 4.37°C in the period 1946-1990. This is attributed to the recent high variability in the North Atlantic Oscillation (NAO) Index. Annual precipitation has increased significantly during the period 1880-1993. The period 1946-1990 was wetter than 1901-1945, with greater variability particularly in the summer months, which contribute most to the annual precipitation in Lapland.

  5. 100 years of Epilepsia: landmark papers and their influence in neuropsychology and neuropsychiatry.

    PubMed

    Hermann, Bruce

    2010-07-01

    As part of the 2009 International League Against Epilepsy (ILAE) Centenary Celebration, a special symposium was dedicated to Epilepsia (100 Years of Epilepsia: Landmark Papers and Their Influence). The Associate Editors were asked to identify a particularly salient and meaningful paper in their areas of expertise. From the content areas of neuropsychology and neuropsychiatry two very interesting papers were identified using quite different ascertainment techniques. One paper addressed the problem of psychosis in temporal lobe epilepsy, whereas the other represents the first paper to appear in Epilepsia presenting quantitative assessment of cognitive status in epilepsy. These two papers are reviewed in detail and placed in historical context.

  6. Fascia Research Congress evidence from the 100 year perspective of Andrew Taylor Still.

    PubMed

    Findley, Thomas W; Shalwala, Mona

    2013-07-01

    More than 100 years ago A.T. Still MD founded osteopathic medicine, and specifically described fascia as a covering, with common origins of layers of the fascial system despite diverse names for individual parts. Fascia assists gliding and fluid flow and is highly innervated. Fascia is intimately involved with respiration and with nourishment of all cells of the body, including those of disease and cancer. This paper reviews information presented at the first three International Fascia Research Congresses in 2007, 2009 and 2012 from the perspective of Dr Still, that fascia is vital for organism's growth and support, and it is where disease is sown.

  7. 100 years since the discovery of cosmic rays. A brief history

    NASA Astrophysics Data System (ADS)

    Chiavassa, Andrea

    2012-11-01

    With the words "Cosmic Rays" we mean particles impinging on the earth atmosphere. The existence of these particles was discovered in 1912, i.e. exactly 100 years ago, by the Austrian physicist Victor Hesss. In this contribution I will describe the steps that lead to such a discovery: from the electroscope measurements, showing their spontaneous discharge, to the correct explanation of this results with the existence of charged particles arriving from outside of the atmosphere. Then I will discuss the first steps of experimental particle physics, obtained with experiments performed detecting cosmic rays, that allowed important discoveries as the detection of antimatter and of new subatominc particles as muons and pions.

  8. 100 years of mapping the Holocene Rhine-Meuse delta plain: combining research and teaching

    NASA Astrophysics Data System (ADS)

    Cohen, K. M.; Stouthamer, E.; Hoek, W. Z.; Middelkoop, H.

    2012-04-01

    The history of modern soil, geomorphological and shallow geological mapping in the Holocene Rhine-Meuse delta plain goes back about 100 years. The delta plain is of very heterogeneous build up, with clayey and peaty flood basins, dissected by sandy fluvial distributary channel belts with fine textured levees grading into tidal-influenced rivers and estuaries. Several generations of precursor rivers occur as alluvial ridges and buried ribbon sands. They form an intricate network originating from repeated avulsions, back to 8000 years ago. Present rivers have been embanked since ca. 1250 AD and the delta plain (~ 3000 km2) has been reclaimed for agriculture. Soils are young and subject to oxidation and compaction. The first detailed field map of channel belts and floodbasins was made in 1926 by Vink, a geography teacher from Amsterdam. Soil mapping and Holocene geology gained interest after WW-II, with Wageningen soil scientists Edelman, Hoeksema and Pons taking lead. Utrecht University started teaching and research on the subject in 1959, launching an undergraduate mapping field course based on hand augering and field observation. An archive of borehole logs and local maps started to build up. Initially focused on soil mapping, from 1973 the course shifted to a geomorphological-geological focus. Berendsen took over supervision, introduced standard description protocols and legends and increased coring depth. This resulted in 1982 in his influential PhD thesis on the Rhine delta's genesis. New coring and sampling methods came and extensive 14C dating campaigns began. With steadily increasing numbers of students, accumulation of data speeded up, and increasingly larger parts of the delta were mapped. The academic mapping ran in parallel with soil survey and geological survey mapping campaigns. The computer was introduced in the field course and digital data archiving began in 1989. A series of PhD studies on thematic aspects of delta evolution and an increasing number

  9. Solar wind variations in the 60-100 year period range: A review

    NASA Technical Reports Server (NTRS)

    Feynman, J.

    1983-01-01

    The evidence for and against the reality of a solar wind variation in the period range of 60-100 years is reexamined. Six data sets are reviewed; sunspot numbers, geomagnetic variations, two auroral data sets and two (14)C data sets. These data are proxies for several different aspects of the solar wind and the presence or absence of 60-100 year cyclic behavior in a particular data set does not necessarily imply the presence or absence of this variation in other sets. It was concluded that two different analyses of proxy data for a particular characteristic of the heliospheric solar wind yielded conflicting results. This conflict can be resolved only by future research. It is also definitely confirmed that proxy data for the solar wind in the ecliptic at 1 A.U. undergo a periodic variation with a period of approximately 87 years. The average amplitude and phase of this variation as seen in eleven cycles of proxy data are presented.

  10. 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.

  11. Horizon dynamics of distorted rotating black holes

    SciTech Connect

    Chu, Tony; Cohen, Michael I.; Pfeiffer, Harald P.

    2011-05-15

    We present numerical simulations of a rotating black hole distorted by a pulse of ingoing gravitational radiation. For strong pulses, we find up to five concentric marginally outer trapped surfaces. These trapped surfaces appear and disappear in pairs, so that the total number of such surfaces at any given time is odd. The world tubes traced out by the marginally outer trapped surfaces are found to be spacelike during the highly dynamical regime, approaching a null hypersurface at early and late times. We analyze the structure of these marginally trapped tubes in the context of the dynamical horizon formalism, computing the expansion of outgoing and incoming null geodesics, as well as evaluating the dynamical horizon flux law and the angular momentum flux law. Finally, we compute the event horizon. The event horizon is well-behaved and approaches the apparent horizon before and after the highly dynamical regime. No new generators enter the event horizon during the simulation.

  12. 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.

  13. Sedimentary records of eutrophication and hypoxia in the Changjiang Estuary over the last 100 years

    NASA Astrophysics Data System (ADS)

    Xuwen, F.; Hongliang, L.; Zhao, M.; Xuefa, S.

    2012-12-01

    We selected two cores in the Changjiang Estuary, one located in the Changjiang Estuary mud area (CEMA) within the region of seasonal hypoxia, the other located in the Cheju Island mud area (SCIMA) and outside the hypoxia region. The grain size, total organic carbon (TOC), stable carbon isotopic ratios (δ13 Corg), biomarkers (the sum of brassicasterol, dinosterol and alkenone) and some redox sensitive elements (RSEs) were determined on the 210Pb-dated sediment cores to study potential hundrend-years eutrophication and hypoxia. The sediment record in CEMA showed that an increase in TOC (21%), biomarkers (141%) and δ13 Corg (1.6‰PDB ) occurred since 1950s and a marked increase since 1970s. These distributions indicated the enhanced productivity and establshed the history of eutrophication in the Changjiang Estuary during the past 100 years. Some RSEs have been enriched significantly since the late 1960s to 1970s, the rates of Mo/Al, Cd/Al and As/Al increased about 83%, 73% and 50% respectively. These data may indicate the onset of hypoxia in the Changjiang Estuary during the last 100 years. The increasing of marine organic matter and RSEs accumulation was corresponding with the fertilizer consumption and high nutrient inputs from the Changjiang River. The riverine runoff of fertilizers and nutrients stimulated the algae (e g. brassicasterol, dinosterol) blooming. Enhanced primary production resulted in an enrichment of organic matter and hypoxia invoked organic matter preserved in the sediment. For the core sediment in SCIMA, the geochemical indicators (TOC, biomarkers and δ13Corg ) increased in difference degrees before 1950s~1970s and then were almost the constant. Productivity in the SCIMA have been mainly influenced by climate ocean circulation changes over the last 100 years. The RSEs were controlled by "grain size effects" which indicated no hypoxia occurred. This study concluded that δ13 Corg, RSEs and biomarkers in sediment could be used to trace or

  14. 100-year DASCH Light Curves of Kepler Planet-Candidate Host Stars

    NASA Astrophysics Data System (ADS)

    Tang, Sumin; Sasselov, Dimitar; Grindlay, Jonathan; Los, Edward; Servillat, Mathieu

    2013-07-01

    We present 100 year light curves of Kepler planet-candidate host stars from the Digital Access to a Sky Century at Harvard (DASCH) project. 261 out of 997 host stars have at least 10 good measurements on DASCH scans of the Harvard plates. 109 of them have at least 100 good measurements, including 70% (73 out of 104) of all host stars with g ≤ 13 mag, and 44% (100 out of 228) of all host stars with g ≤ 14 mag. Our typical photometric uncertainty is ∼0.1–0.15 mag. No variation is found at 3σ level for these host stars, including 21 confirmed or candidate hot Jupiter systems which might be expected to show enhanced flares from magnetic interactions between dwarf primaries and their close and relatively massive planet companions.

  15. 100 years of Pb deposition and transport in soils in Champaign, Illinois, U.S.A

    USGS Publications Warehouse

    Zhang, Y.

    2003-01-01

    In Illinois, atmospheric deposition is one major source of heavy metal inputs to agricultural land. The atmospheric Pb deposition and transport record in agricultural soils in Champaign, Illinois, was established by studying surface and subsurface soil samples collected during the past 100 years from the Morrow Plots on the campus of the University of Illinois at Urbana-Champaign. The Pb content in the soil samples was measured and the Ph deposition fluxes were calculated. The Pb content in surface soils increased sharply in the first half of the 20th century, and stayed invariant since. The maximum Pb flux from the atmosphere was estimated to be 27 (??14) ??g cm-2 yr-1 around 1940. The major pollution source for this increase probably was residential coal burning. It was estimated that in 50 yr, more than 50% of the Pb input had been lost from the surface soils.

  16. The Reissner Canard: The first all-metal airplane 100 years ago

    NASA Astrophysics Data System (ADS)

    Krause, Egon

    2012-10-01

    In 1912 Professor Hans Reissner of the Technical University Aachen built a canard-type aeroplane, the world-wide first completely out of metal: although the Reissner Canard initiated a new technology with the Junkers J1 the first to follow in 1915 and 1000 more until now, little is known about the very first steps way back in Aachen. This paper tries to recapture some details of the developments 100 years ago with the aid of early publications and photographs and shed some light on the first wing fabricated out of a corrugated aluminum sheet mounted at the tail of the braced-steel-pipe fuselage to earn its airworthiness in Berlin Johannisthal in 1912.

  17. Sustainable Foods and Medicines Support Vitality, Sex and Longevity for a 100-Year Starship Expedition

    NASA Astrophysics Data System (ADS)

    Edwards, M. R.

    Extended space flight requires foods and medicines that sustain crew health and vitality. The health and therapeutic needs for the entire crew and their children for a 100-year space flight must be sustainable. The starship cannot depend on resupply or carry a large cargo of pharmaceuticals. Everything in the starship must be completely recyclable and reconstructable, including food, feed, textiles, building materials, pharmaceuticals, vaccines, and medicines. Smart microfarms will produce functional foods with superior nutrition and sensory attributes. These foods provide high-quality protein and nutralence (nutrient density), that avoids obesity, diabetes, and other Western diseases. The combination of functional foods, lifestyle actions, and medicines will support crew immunity, energy, vitality, sustained strong health, and longevity. Smart microfarms enable the production of fresh medicines in hours or days, eliminating the need for a large dispensary, which eliminates concern over drug shelf life. Smart microfarms are adaptable to the extreme growing area, resource, and environmental constraints associated with an extended starship expedition.

  18. Secular changes in growth among Japanese children over 100 years (1900-2000).

    PubMed

    Kagawa, Masaharu; Tahara, Yasuaki; Moji, Kazuhiko; Nakao, Rieko; Aoyagi, Kiyoshi; Hills, Andrew P

    2011-01-01

    Human growth is associated with complex interactions between genetic and environmental factors. While research has reported increased body size and body mass index (BMI) of Japanese children, few studies have compared the magnitude of increments in growth before and after World War II (WW II) and also considered other social and economical events that may have influenced the growth of children. The current study assessed the secular change in growth in Japanese children and adolescents aged between 6 and 17 years using data from the School Health Statistics Survey conducted between 1900 and 2000 with consideration of key social changes during the 20th Century. Over the 100-year period, Japanese boys had height and weight increments of 1.0-2.0 cm per decade and 0.4-1.7 kg per decade whereas girls had rates of 1.1-1.9 cm and 0.4-1.5 kg per decade, respectively. The rates of height increment were significantly (p<0.05) different between pre-, during and post-WW II periods. While Japanese children were considerably larger in 2000 compared to 1900, increments between 1950 and 1960 reflected catch-up growth to restore physical size seen in children prior to WW II. The increments in body size continued after 1960 with greatest changes seen across the pubertal years. While increments in BMI were evident in most age groups, the BMI of 17-year-old girls was consistent over the 100 years. Results clarified secular changes in growth in Japanese school children across the 20th Century and possible factors contributing to these changes.

  19. 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…

  20. 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/

  1. Stringy horizons II

    NASA Astrophysics Data System (ADS)

    Giveon, Amit; Itzhaki, Nissan; Kutasov, David

    2016-10-01

    We show that the spectrum of normalizable states on a Euclidean SL(2, R)/U(1) black hole exhibits a duality between oscillator states and wound strings. This duality generalizes the identification between a normalizable mode of dilaton gravity on the cigar and a mode of the tachyon with winding number one around the Euclidean time circle, which plays an important role in the FZZ correspondence. It implies that normalizable states on a large Euclidean black hole have support at widely separated scales. In particular, localized states that are extended over the cap of the cigar (the Euclidian analog of the black hole atmosphere) have a component that is localized near the tip of the cigar (the analog of the stretched horizon). As a consequence of this duality, the states exhibit a transition as a function of radial excitation level. From the perspective of a low energy probe, low lying states are naturally thought of as oscillator states in the black hole atmosphere, while at large excitation level they are naturally described as wound strings. As the excitation level increases, the size of the states first decreases and then increases. This behavior is expected to be a general feature of black hole horizons in string theory.

  2. Stages of the pathologic process in Alzheimer disease: age categories from 1 to 100 years.

    PubMed

    Braak, Heiko; Thal, Dietmar R; Ghebremedhin, Estifanos; Del Tredici, Kelly

    2011-11-01

    Two thousand three hundred and thirty two nonselected brains from 1- to 100-year-old individuals were examined using immunocytochemistry (AT8) and Gallyas silver staining for abnormal tau; immunocytochemistry (4G8) and Campbell-Switzer staining were used for the detection ofβ-amyloid. A total of 342 cases was negative in the Gallyas stain but when restaged for AT8 only 10 were immunonegative. Fifty-eight cases had subcortical tau predominantly in the locus coeruleus, but there was no abnormal cortical tau (subcortical Stages a-c). Cortical involvement (abnormal tau in neurites) was identified first in the transentorhinal region (Stage 1a, 38 cases). Transentorhinal pyramidal cells displayed pretangle material (Stage 1b, 236 cases). Pretangles gradually became argyrophilic neurofibrillary tangles (NFTs) that progressed in parallel with NFT Stages I to VI. Pretangles restricted to subcortical sites were seen chiefly at younger ages. Of the total cases, 1,031 (44.2%) had β-amyloid plaques. The first plaques occurred in the neocortex after the onset of tauopathy in the brainstem. Plaques generally developed in the 40s in 4% of all cases, culminating in their tenth decade (75%). β-amyloid plaques and NFTs were significantly correlated (p < 0.0001). These data suggest that tauopathy associated with sporadic Alzheimer disease may begin earlier than previously thought and possibly in the lower brainstem rather than in the transentorhinal region.

  3. Physiological and morphological acclimation to height in cupressoid leaves of 100-year-old Chamaecyparis obtusa.

    PubMed

    Shiraki, Ayumi; Azuma, Wakana; Kuroda, Keiko; Ishii, H Roaki

    2016-10-15

    Cupressoid (scale-like) leaves are morphologically and functionally intermediate between stems and leaves. While past studies on height acclimation of cupressoid leaves have focused on acclimation to the vertical light gradient, the relationship between morphology and hydraulic function remains unexplored. Here, we compared physiological and morphological characteristics between treetop and lower-crown leaves of 100-year-old Chamaecyparis obtusa Endl. trees (~27 m tall) to investigate whether height-acclimation compensates for hydraulic constraints. We found that physiological acclimation of leaves was determined by light, which drove the vertical gradient of evaporative demand, while leaf morphology and anatomy were determined by height. Compared with lower-crown leaves, treetop leaves were physiologically acclimated to water stress. Leaf hydraulic conductance was not affected by height, and this contributed to higher photosynthetic rates of treetop leaves. Treetop leaves had higher leaf area density and greater leaf mass per area, which increase light interception but could also decrease hydraulic efficiency. We inferred that transfusion tissue flanking the leaf vein, which was more developed in the treetop leaves, contributes to water-stress acclimation and maintenance of leaf hydraulic conductance by facilitating osmotic adjustment of leaf water potential and efficient water transport from xylem to mesophyll. Our findings may represent anatomical adaptation that compensates for hydraulic constraints on physiological function with increasing height.

  4. [Nutrient dynamics over the past 100 years and its restoration baseline in Dianshan Lake].

    PubMed

    Li, Xiao-Ping; Chen, Xiao-Hua; Dong, Xu-Hui; Dong, Zhi; Sun, Dun-Ping

    2012-10-01

    The restoration of eutrophic lakes requires a good knowledge on the history and baseline of nutrients in the lakes. This work conducted an analysis on 210Pb/137Cs, water content, loss-on-ignition, sedimentary total phosphorus (TP), total nitrogen (TN), total organic carbon (TOC) and diatoms in the four sediment cores from Dianshan Lake (near Shanghai City). Good coherence in palaeoproxies between the cores indicates a relatively stable sedimentary environment. With increasing human impact, diatom communities shifted from oligo-trophic species Cyclotella bodanica, C. ocelata, Achnanthes minutissima, Cocconeis placentula var lineate, Cymbella sp. , Fragilaria pintata, F. brevistrata, F. construens var venter to recent eutrophic species including Cyclostephanos dubias, C. atomus, Stephanodiscus minitulus, S. hantzschi, Aulacoseria alpigena. The epilimnetic TP over the past 100 years reconstructed using an established diatom-TP transfer function matches well with the monitoring TP where exists. Based on the sedimentary nutrient characteristics and diatom-reconstructed nutrient dynamics, we proposed that the nutrient baseline for Dianshan Lake is 50-60 microg x L(-1), 500 mg x kg(-1) and 550 mg x kg(-1) for water TP concentration, sedimentary TP and TN, respectively.

  5. Revisiting extreme storms of the past 100 years for future safety of large water management infrastructures

    NASA Astrophysics Data System (ADS)

    Chen, Xiaodong; Hossain, Faisal

    2016-07-01

    Historical extreme storm events are widely used to make Probable Maximum Precipitation (PMP) estimates, which form the cornerstone of large water management infrastructure safety. Past studies suggest that extreme precipitation processes can be sensitive to land surface feedback and the planetary warming trend, which makes the future safety of large infrastructures questionable given the projected changes in land cover and temperature in the coming decades. In this study, a numerical modeling framework was employed to reconstruct 10 extreme storms over CONUS that occurred during the past 100 years, which are used by the engineering profession for PMP estimation for large infrastructures such as dams. Results show that the correlation in daily rainfall for such reconstruction can range between 0.4 and 0.7, while the correlation for maximum 3-day accumulation (a standard period used in infrastructure design) is always above 0.5 for post-1948 storms. This suggests that current numerical modeling and reanalysis data allow us to reconstruct big storms after 1948 with acceptable accuracy. For storms prior to 1948, however, reconstruction of storms shows inconsistency with observations. Our study indicates that numerical modeling and data may not have advanced to a sufficient level to understand how such old storms (pre-1948) may behave in future warming and land cover conditions. However, the infrastructure community can certainly rely on the use of model reconstructed extreme storms of the 1948-present period to reassess safety of our large water infrastructures under assumed changes in temperature and land cover.

  6. Under Connecticut Skies: Exploring 100 Years of Astronomy at Van Vleck Observatory in Middletown, Connecticut

    NASA Astrophysics Data System (ADS)

    Kilgard, Roy E.; Williams, Amrys; Erickson, Paul; Herbst, William; Redfield, Seth

    2017-01-01

    Under Connecticut Skies examines the history of astronomy at Van Vleck Observatory, located on the campus of Wesleyan University in Middletown, Connecticut. Since its dedication in June of 1916, Van Vleck has been an important site of astronomical research, teaching, and public outreach. Over a thousand visitors pass through the observatory each year, and regular public observing nights happen year-round in cooperation with the Astronomical Society of Greater Hartford. Our project explores the place-based nature of astronomical research, the scientific instruments, labor, and individuals that have connected places around the world in networks of observation, and the broader history of how observational astronomy has linked local people, amateur observers, professional astronomers, and the tools and objects that have facilitated their work under Connecticut’s skies over the past 100 years. Our research team has produced a historical exhibition to help commemorate the observatory’s centennial that opened to the public in May of 2016. Our work included collecting, documenting, and interpretting this history through objects, archival documents, oral histories, photographs, and more. The result is both a museum and a working history "laboratory" for use by student and professional researchers. In addition to the exhibit itself, we have engaged in new interpretive programs to help bring the history of astronomy to life. Future work will include digitization of documents and teaching slides, further collection of oral histories, and expanding the collection to the web for use by off-site researches.

  7. PREFACE: Celebrating 100 years of superconductivity: special issue on the iron-based superconductors Celebrating 100 years of superconductivity: special issue on the iron-based superconductors

    NASA Astrophysics Data System (ADS)

    Crabtree, George; Greene, Laura; Johnson, Peter

    2011-12-01

    In honor of this year's 100th anniversary of the discovery of superconductivity, this special issue of Reports on Progress in Physics is a dedicated issue to the 'iron-based superconductors'—a new class of high-temperature superconductors that were discovered in 2008. This is the first time the journal has generated a 'theme issue', and we provide this to the community to provide a 'snapshot' of the present status, both for researchers working in this fast-paced field, and for the general physics community. Reports on Progress in Physics publishes three classes of articles—comprehensive full Review Articles, Key Issues Reviews and, most recently, Reports on Progress articles that recount the current status of a rapidly evolving field, befitting of the articles in this special issue. It has been an exciting year for superconductivity—there have been numerous celebrations for this centenary recounting the fascinating history of this field, from seven Nobel prizes to life-saving discoveries that brought us medically useful magnetic resonance imaging. The discovery of a completely new class of high-temperature superconductors, whose mechanism remains as elusive as the cuprates discovered in 1986, has injected a new vitality into this field, and this year those new to the field were provided with the opportunity of interacting with those who have enjoyed a long history in superconductivity. Furthermore, as high-density current carriers with little or no power loss, high-temperature superconductors offer unique solutions to fundamental grid challenges of the 21st century and hold great promise in addressing our global energy challenges. The complexity and promise of these materials has caused our community to more freely share our ideas and results than ever before, and it is gratifying to see how we have grown into an enthusiastic global network to advance the field. This invited collection is true to this agenda and we are delighted to have received contributions

  8. An epidemiological review of changes in meningococcal biology during the last 100 years

    PubMed Central

    Abio, Anne; Neal, Keith R; Beck, Charles R

    2013-01-01

    Aim The aim of this study was to assess changes in trends of meningococcal disease and strain diversity of Neisseria meningitidis in Europe, South America, and Africa over the last 100 years. Methods Healthcare databases and sources of grey literature were searched in 2012 and records were screened against the protocol eligibility criteria using a three-stage sifting process. Studies included in the review were subject to data extraction. Results were summarised using a narrative approach. Results Serogroup A was the dominant cause of invasive meningococcal disease in Europe before and during World Wars I and II. Whilst serogroup B has been dominant from the 1970s in Europe and the 1980s in South America, outbreaks have emerged associated with serogroups W135 and Y in the twenty-first century. There has been a shift in the age groups affected by invasive meningococcal disease with an increase in incidence among the elderly associated with serogroup Y and a decline in serogroup C among adolescent populations. Recent outbreaks of serogroup W135 have occurred in some countries in South America. The epidemiological trend of invasive meningococcal disease has remained largely static across Africa and dominated by serogroup A although recently serogroups X and W135 have accounted for a large proportion of morbidity and mortality. Conclusion The epidemiology of N. meningitidis has been dynamic in Europe and South America especially over the last 30 years. Routine vaccination with serogroup C vaccines has led to reduced carriage and incidence of invasive meningococcal disease and herd immunity. PMID:24392681

  9. Caspian tern reproduction in the Saginaw Bay ecosystem following a 100-year flood event

    USGS Publications Warehouse

    Ludwig, James P.; Auman, Heidi J.; Kurita, Hiroko; Ludwig, Matthew E.; Campbell, Loraine M.; Giesy, John P.; Tillitt, Donald E.; Jones, Paul; Yamashita, Nobu; Tanabe, Shinsuke; Tatsukawa, Ryo

    1993-01-01

    In the 2 years that followed the 100-year flood incident of September 1986 in the Saginaw River/Bay ecosystem, the reproduction of Caspian terns collapsed and then slowly recovered. Egg viability and fledging rates of hatched chicks were drastically depressed in 1987 and 1988. Eggs from clutches laid later in the year were less viable and chicks hatched from these eggs displayed wasting syndromes and deformities. The post-flood rate of deformities in hatched chicks in 1987–1989 was 163-fold greater than background rates for this population in 1962–1967. Embryonic abnormalities and deformities were found in many embryos recovered from dead eggs. Recently published data on planar toxic chemicals from samples of forage fish, tern eggs, and chicks from water birds nesting in the bay implicate planar dioxin-like PCBs 77 and 126 as the sources of these severe bioeffects. The planar PCB congeners accounted for >98% of TCDD-EQ toxicity in the tern eggs, and several were present at levels near or at the LD95 levels each for chicken eggs. Actual TCDD was about 1% of the TCDD-EQ toxicity. Very rapid buildup rates of PCBs were measured in tern eggs. The calculated toxic potency of PCB recovered from tern eggs was about 15-fold greater than parent aroclor 1242 PCB. Smaller tern species were projected to be much more at risk than the larger Caspian tern due to greater standard metabolic rates. The study supports the view that sediment disturbance and sediment banks of toxic chemicals are major threats to upper trophic level fish-eating species.

  10. To Humbly Go: Guarding Against Perpetuating Models of Colonization in the 100-Year Starship Study

    NASA Astrophysics Data System (ADS)

    Kramer, W. R.

    Past patterns of exploration, colonization and exploitation on Earth continue to provide the predominant paradigms that guide many space programs. Any project of crewed space exploration, especially of the magnitude envisioned by the 100-Year Starship Study, must guard against the hubris that may emerge among planners, crew, and others associated with the project, including those industries and bureaucracies that will emerge from the effort. Maintaining a non-exploitative approach may be difficult in consideration of the century of preparatory research and development and the likely multigenerational nature of the voyage itself. Starting now with mission dreamers and planners, the purpose of the voyage must be cast as one of respectful learning and humble discovery, not of conquest (either actual or metaphorical) or other inappropriate models, including military. At a minimum, the Study must actively build non-violence into the voyaging culture it is beginning to create today. References to exploitive colonization, conquest, destiny and other terms from especially American frontier mythology, while tempting in their propagandizing power, should be avoided as they limit creative thinking about alternative possible futures. Future voyagers must strive to adapt to new environments wherever possible and be assimilated by new worlds both biologically and behaviorally rather than to rely on attempts to recreate the Earth they have left. Adaptation should be strongly considered over terraforming. This paper provides an overview of previous work linking the language of colonization to space programs and challenges the extension of the myth of the American frontier to the Starship Study. It argues that such metaphors would be counter-productive at best and have the potential to doom long-term success and survival by planting seeds of social decay and self-destruction. Cautions and recommendations are suggested.

  11. 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.

  12. Climatic and Hydrological Changes of Past 100 Years in Asian Arid Zone

    NASA Astrophysics Data System (ADS)

    Feng, Zhaodong; Salnikov, Vitaliy; Xu, Changchun

    2014-05-01

    The Asian Arid Zone (AAZ) is here defined to include the following regions: northwestern China, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. Generally speaking, the AAZ has experienced a temperature rising during the past 100 years that was significantly faster than the global average (0.14 ºC per decade). Specifically, the rate was 0.39 ºC per decade in northwestern China (1950-2010), 0.26 ºC per decade in Kazakhstan (1936-2005), 0.22 ºC per decade in Mongolia (1940-2010), 0.29 ºC per decade in Uzbekistan (1950-2005), 0.18 ºC per decade in Turkmenistan (1961-1995). It should be noted that the mountainous parts of AAZ seems to have experienced a slower rate of temperature rising. For example, the rate was 0.10 ºC per decade in Tajikistan (1940-2005) and was 0.08 ºC per decade in Kyrgyzstan (1890-2005). Precipitation has a slight increasing trend in northwestern China, but it has fluctuated along a near-constant line in the rest of the AAZ. Hydrological data from high-elevation basin show that the runoff has been increasing primarily as a result of rising temperature that caused increases in ice melting. A natural decreasing trend of surface runoff in low-elevation basins is undeniable and the decreasing trend is attributable to intensified evaporation under warming conditions. It is true that the total amount of runoff in the Tianshan Mountains and the associated basins has been increased primarily as a result of temperature rising-resulted increases in ice melting. But, approaching to the turning point of glacier-melting supplies to runoff will pose a great threat to socio-economic sustainability and to ecological security. The turning point refers to the transition from increasing runoff to decreasing runoff within ice melting supplied watersheds under a warming climate.

  13. Combining Neural Networks with Existing Methods to Estimate 1 in 100-Year Flood Event Magnitudes

    NASA Astrophysics Data System (ADS)

    Newson, A.; See, L.

    2005-12-01

    Over the last fifteen years artificial neural networks (ANN) have been shown to be advantageous for the solution of many hydrological modelling problems. The use of ANNs for flood magnitude estimation in ungauged catchments, however, is a relatively new and under researched area. In this paper ANNs are used to make estimates of the magnitude of the 100-year flood event (Q100) for a number of ungauged catchments. The data used in this study were provided by the Centre for Ecology and Hydrology's Flood Estimation Handbook (FEH), which contains information on catchments across the UK. Sixteen catchment descriptors for 719 catchments were used to train an ANN, which was split into a training, validation and test data set. The goodness-of-fit statistics on the test data set indicated good model performance, with an r-squared value of 0.8 and a coefficient of efficiency of 79 percent. Data for twelve ungauged catchments were then put through the trained ANN to produce estimates of Q100. Two other accepted methodologies were also employed: the FEH statistical method and the FSR (Flood Studies Report) design storm technique, both of which are used to produce flood frequency estimates. The advantage of developing an ANN model is that it provides a third figure to aid a hydrologist in making an accurate estimate. For six of the twelve catchments, there was a relatively low spread between estimates. In these instances, an estimate of Q100 could be made with a fair degree of certainty. Of the remaining six catchments, three had areas greater than 1000km2, which means the FSR design storm estimate cannot be used. Armed with the ANN model and the FEH statistical method the hydrologist still has two possible estimates to consider. For these three catchments, the estimates were also fairly similar, providing additional confidence to the estimation. In summary, the findings of this study have shown that an accurate estimation of Q100 can be made using the catchment descriptors of

  14. Infrared survey of 50 buildings constructed during 100 years: thermal performances and damage conditions

    NASA Astrophysics Data System (ADS)

    Ljungberg, Sven-Ake

    1995-03-01

    Different building constructions and craftsmanship give rise to different thermal performance and damage conditions. The building stock of most industrial countries consists of buildings of various age, and constructions, from old historic buildings with heavy stone or wooden construction, to new buildings with heavy or light concrete construction, or modern steel or wooden construction. In this paper the result from a detailed infrared survey of 50 buildings from six Swedish military camps is presented. The presentation is limited to a comparison of thermal performance and damage conditions of buildings of various ages, functions, and constructions, of a building period of more than 100 years. The result is expected to be relevant even to civilian buildings. Infrared surveys were performed during 1992-1993, with airborne, and mobile short- and longwave infrared systems, out- and indoor thermography. Interpretation and analysis of infrared data was performed with interactive image and analyzing systems. Field inspections were carried out with fiber optics system, and by ocular inspections. Air-exchange rate was measured in order to quantify air leakages through the building envelope, indicated in thermograms. The objects studied were single-family houses, barracks, office-, service-, school- and exercise buildings, military hotels and restaurants, aircraft hangars, and ship factory buildings. The main conclusions from this study are that most buildings from 1880 - 1940 have a solid construction with a high quality of craftsmanship, relatively good thermal performance, due to extremely thick walls, and adding insulation at the attic floor. From about 1940 - 1960 the quality of construction, thermal performance and craftsmanship seem to vary a lot. Buildings constructed during the period of 1960 - 1990 have in general the best thermal performance due to a better insulation capacity, however, also one finds here the greatest variety of problems. The result from this

  15. 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…

  16. 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…

  17. Anomaly corrected heterotic horizons

    NASA Astrophysics Data System (ADS)

    Fontanella, A.; Gutowski, J. B.; Papadopoulos, G.

    2016-10-01

    We consider supersymmetric near-horizon geometries in heterotic supergravity up to two loop order in sigma model perturbation theory. We identify the conditions for the horizons to admit enhancement of supersymmetry. We show that solutions which undergo supersymmetry enhancement exhibit an {s}{l}(2,{R}) symmetry, and we describe the geometry of their horizon sections. We also prove a modified Lichnerowicz type theorem, incorporating α' corrections, which relates Killing spinors to zero modes of near-horizon Dirac operators. Furthermore, we demonstrate that there are no AdS2 solutions in heterotic supergravity up to second order in α' for which the fields are smooth and the internal space is smooth and compact without boundary. We investigate a class of nearly supersymmetric horizons, for which the gravitino Killing spinor equation is satisfied on the spatial cross sections but not the dilatino one, and present a description of their geometry.

  18. 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.

  19. Parity horizons in shape dynamics

    NASA Astrophysics Data System (ADS)

    Herczeg, Gabriel

    2016-11-01

    I introduce the notion of a parity horizon, and show that many simple solutions of shape dynamics possess them. I show that the event horizons of the known asymptotically flat black hole solutions of shape dynamics are parity horizons and that this notion of parity implies that these horizons possess a notion of CPT invariance that can in some cases be extended to the solution as a whole. I present three new solutions of shape dynamics with parity horizons and find that not only do event horizons become parity horizons in shape dynamics, but observer-dependent horizons and Cauchy horizons do as well. The fact that Cauchy horizons become (singular) parity horizons suggests a general chronology protection mechanism in shape dynamics that prevents the formation of closed timelike curves.

  20. 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.

  1. Russian pioneers of therapeutic hemapheresis and extracorporeal hemocorrection: 100-year anniversary of the world's first successful plasmapheresis.

    PubMed

    Sokolov, Alexey A; Solovyev, Andrey G

    2014-04-01

    On 15 February 2013 (2 February on the Julian Calendar) we celebrated the 100-year anniversary of the world's first successful experimental plasmapheresis. Scientific research projects in this field were carried out by the Department of Infectious Disease, Russian Imperial Medical Surgical Academy located in Saint-Petersburg. Doctor of Medical Sciences and Professor Vadim A. Yurevich was a Principal Investigator for this research, which in 1913 resulted in the discovery of a new way of treatment. The results were published in Russki Vratch (Russian Physician) Journal no. 18 (1914) - V.A. Yurevich and N.K. Rosenberg "For the Question Regarding Washing of Blood Outside of the Body and the Vitality of Red Blood Cells". There was no terminology offered for this medical innovation at that time. Plasma removal was performed not solely, but in combination with washing of blood cells returned to the patient. Nowadays this combination is still considered to be more effective than separate plasmapheresis. According to the published experimental protocols this new treatment was done on 15 February (2 February on the Julian Calendar or "old style"). One year later in 1914 a famous researcher, John Abel and coauthors, repeated a separate plasma removal treatment with retransfusion of the blood cells and suggested the term "plasmapheresis", which is now official. The article entitled "Plasma Removal With Return of Corpuscles (Plasmapheresis)", written by Abel was published 3 months later than the article by Professor Yurevich. In 1924, Dr Ivan P. Mikhailovskiy repeated experiments by Yurevich and Rosenberg in vivo on a dog model, confirmed the clinical efficiency and developed the methodology in his article "Washing of Blood In Vivo, the Methodology, Problems, and Importance for the Treatment of Toxic Conditions."

  2. Looking toward the Future: New Research Helps Black Sororities and Fraternities Consider New Governing Structures for the Next 100 Years

    ERIC Educational Resources Information Center

    Ruffins, Paul

    2004-01-01

    From a historical perspective, it's interesting to note that at their 100-year mark Black fraternities and sororities are facing some of the very same political criticisms encountered half a century ago. The Black Greeks' ability to be a greater force for social change is also constrained by the basic internal structures of the organizations…

  3. The Bee Disease Diagnostic Service - 100 Years and Growing at the USDA Bee Research laboratory, Beltsville, MD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article discusses the history of honey bee research in the Washington, D.C. area including the 100 year old bee disease diagnostic service available for beekeepers and apiary inspectors. This service provides the Bee Research Laboratory with first-hand knowledge of the problems facing the beek...

  4. Flood boundaries and water-surface profile for the computed 100-year flood, Swift Creek at Afton, Wyoming, 1986

    USGS Publications Warehouse

    Rankl, James G.; Wallace, Joe C.

    1989-01-01

    Flood flows on Swift Creek near Afton, Wyoming, were analyzed. Peak discharge with an average recurrence interval of 100 years was computed and used to determine the flood boundaries and water surface profile in the study reach. The study was done in cooperation with Lincoln County and the Town of Afton to determine the extent of flooding in the Town of Afton from a 100-year flood on Swift Creek. The reach of Swift Creek considered in the analysis extends upstream from the culvert at Allred County Road No. 12-135 to the US Geological Survey streamflow-gaging station located in the Bridger National Forest , a distance of 3.2 miles. Boundaries of the 100-year flood are delineated on a map using the computed elevation of the flood at each cross section, survey data, and a 1983 aerial photograph. The computed water surface elevation for the 100-year flood was plotted at each cross section, then the lateral extent of the flood was transferred to the flood map. Boundaries between cross sections were sketched using information taken from the aerial photograph. Areas that are inundated, but not part of the active flow, are designated on the cross sections. (Lantz-PTT)

  5. The story of the Hawaiian Volcano Observatory -- A remarkable first 100 years of tracking eruptions and earthquakes

    USGS Publications Warehouse

    Babb, Janet L.; Kauahikaua, James P.; Tilling, Robert I.

    2011-01-01

    The year 2012 marks the centennial of the Hawaiian Volcano Observatory (HVO). With the support and cooperation of visionaries, financiers, scientists, and other individuals and organizations, HVO has successfully achieved 100 years of continuous monitoring of Hawaiian volcanoes. As we celebrate this milestone anniversary, we express our sincere mahalo—thanks—to the people who have contributed to and participated in HVO’s mission during this past century. First and foremost, we owe a debt of gratitude to the late Thomas A. Jaggar, Jr., the geologist whose vision and efforts led to the founding of HVO. We also acknowledge the pioneering contributions of the late Frank A. Perret, who began the continuous monitoring of Kīlauea in 1911, setting the stage for Jaggar, who took over the work in 1912. Initial support for HVO was provided by the Massachusetts Institute of Technology (MIT) and the Carnegie Geophysical Laboratory, which financed the initial cache of volcano monitoring instruments and Perret’s work in 1911. The Hawaiian Volcano Research Association, a group of Honolulu businessmen organized by Lorrin A. Thurston, also provided essential funding for HVO’s daily operations starting in mid-1912 and continuing for several decades. Since HVO’s beginning, the University of Hawaiʻi (UH), called the College of Hawaii until 1920, has been an advocate of HVO’s scientific studies. We have benefited from collaborations with UH scientists at both the Hilo and Mänoa campuses and look forward to future cooperative efforts to better understand how Hawaiian volcanoes work. The U.S. Geological Survey (USGS) has operated HVO continuously since 1947. Before then, HVO was under the administration of various Federal agencies—the U.S. Weather Bureau, at the time part of the Department of Agriculture, from 1919 to 1924; the USGS, which first managed HVO from 1924 to 1935; and the National Park Service from 1935 to 1947. For 76 of its first 100 years, HVO has been

  6. A Centennial Milestone (1910-2010): 100 Years of Youth Suicide Prevention

    ERIC Educational Resources Information Center

    Miller, David N.

    2010-01-01

    Anniversaries are appropriate times for reflecting on the past and planning for the future, and in this 100th anniversary year of Sigmund Freud's famous group meeting--a meeting among a large group of prominent mental health professionals that provides a useful marker and arguable "starting point" for contemporary youth suicide prevention efforts,…

  7. The Pfannenstiel or so called "bikini cut": still effective more than 100 years after first description.

    PubMed

    Kisielinski, K; Conze, J; Murken, A H; Lenzen, N N; Klinge, U; Schumpelick, V

    2004-08-01

    The original Pfannenstiel incision is discussed including the technique, history, current indications, advantages, and disadvantages. Excellent cosmetic results, principles of less traumatic surgery, and a rare incisional hernia complication rate of about 0-2%, as well as long-time use characterise this access path to the pelvic organs first described by the German gynaecologist in 1900. Complications of nerve damage, however, should be recognised, especially when extending the incision too far laterally.

  8. 100 years of virology: from vitalism via molecular biology to genetic engineering.

    PubMed

    Bos, L

    2000-02-01

    The identification of the causative agent of tobacco mosaic disease as a novel pathogen by the Dutch microbiologist Beijerinck is now acknowledged as being the foundation of virology as a discipline distinct from bacteriology. However, as this was contrary to the prevailing theories of the time, it took many years for virology to become firmly established as a separate discipline. The history of virology illustrates how accepted concepts in science evolve by trial and error and the need for a balanced approach when manipulating natural systems.

  9. Accuracy assessment of the ERP prediction method based on analysis of 100-year ERP series

    NASA Astrophysics Data System (ADS)

    Malkin, Z.; Tissen, V. M.

    2012-12-01

    A new method has been developed at the Siberian Research Institute of Metrology (SNIIM) for highly accurate prediction of UT1 and Pole motion (PM). In this study, a detailed comparison was made of real-time UT1 predictions made in 2006-2011 and PMpredictions made in 2009-2011making use of the SNIIM method with simultaneous predictions computed at the International Earth Rotation and Reference Systems Service (IERS), USNO. Obtained results have shown that proposed method provides better accuracy at different prediction lengths.

  10. The Pan American Health Organization's first 100 years: reflections of the Director.

    PubMed

    Alleyne, George A O

    2002-12-01

    The Pan American Health Organization (PAHO) has responded to changing political times and different health challenges and has played a significant role in some of the recent achievements in health in the region of the Americas. Some of the more remarkable health gains of the past 8 years owe their success to the broad principles of equity and Pan-Americanism that guide PAHO's work. The production and use of scientific-technical information is the fundamental underpinning of the technical cooperation that has facilitated the health work of countries. The future is bright for PAHO's next century.

  11. The Pan American Health Organization’s First 100 Years: Reflections of the Director

    PubMed Central

    Alleyne, George A. O.

    2002-01-01

    The Pan American Health Organization (PAHO) has responded to changing political times and different health challenges and has played a significant role in some of the recent achievements in health in the region of the Americas. Some of the more remarkable health gains of the past 8 years owe their success to the broad principles of equity and Pan-Americanism that guide PAHO’s work. The production and use of scientific–technical information is the fundamental underpinning of the technical cooperation that has facilitated the health work of countries. The future is bright for PAHO’s next century. PMID:12453802

  12. Nonlinear optics of fibre event horizons.

    PubMed

    Webb, Karen E; Erkintalo, Miro; Xu, Yiqing; Broderick, Neil G R; Dudley, John M; Genty, Goëry; Murdoch, Stuart G

    2014-09-17

    The nonlinear interaction of light in an optical fibre can mimic the physics at an event horizon. This analogue arises when a weak probe wave is unable to pass through an intense soliton, despite propagating at a different velocity. To date, these dynamics have been described in the time domain in terms of a soliton-induced refractive index barrier that modifies the velocity of the probe. Here we complete the physical description of fibre-optic event horizons by presenting a full frequency-domain description in terms of cascaded four-wave mixing between discrete single-frequency fields, and experimentally demonstrate signature frequency shifts using continuous wave lasers. Our description is confirmed by the remarkable agreement with experiments performed in the continuum limit, reached using ultrafast lasers. We anticipate that clarifying the description of fibre event horizons will significantly impact on the description of horizon dynamics and soliton interactions in photonics and other systems.

  13. Exploring 100+ Year Variability with DASCH: Statistical Methods and Recent Results.

    NASA Astrophysics Data System (ADS)

    Miller, George Franklin; Grindlay, Jonathan E.; Los, Edward

    2014-06-01

    The Digital Access to a Sky Century at Harvard (DASCH) project is currently digitizing the roughly 500,000 photographic plates maintained by the Harvard College Observatory. The Harvard plate collection covers each point of the sky roughly 500 to 3000 times from 1885 to 1992, with limiting magnitudes ranging from B=14-18 mag and photometric accuracy within ±0.1 mag. Production scanning (roughly 400 plates/day) is proceeding in Galactic coordinates from the North Galactic Pole and is currently at roughly 40 degrees galactic latitude. The vastness of these data makes DASCH unique in its ability to systematically study variability on decade-long time scales across the entire sky. We are developing new statistical mining techniques to predictively identify the many classes of stellar variability and explore their long-term behavior, as well as discover new unusual cases/classes of variability. Most recently, we are working to implement wavelet-based algorithms into our mining routines, better allowing us to analyze localized non-periodic signals. Here we report on the progress of our mining and machine learning routines, as well as share several of the exciting new discoveries that are being made with DASCH. We gratefully acknowledge support from NSF grants AST-0407380, AST-0909073 and AST-1313370.

  14. How over 100 years of climate variability may affect estimates of potential evaporation

    NASA Astrophysics Data System (ADS)

    Bartholomeus, R. P.; Stagge, J. H.; Tallaksen, L. M.; Witte, J. P. M.

    2014-09-01

    Hydrological modeling frameworks require an accurate representation of evaporation fluxes for appropriate quantification of e.g. the soil moisture budget, droughts, recharge and groundwater processes. Many frameworks have used the concept of potential evaporation, often estimated for different vegetation classes by multiplying the evaporation from a reference surface ("reference evaporation") with crop specific scaling factors ("crop factors"). Though this two-step potential evaporation approach undoubtedly has practical advantages, the empirical nature of both reference evaporation methods and crop factors limits its usability in extrapolations and non-stationary climatic conditions. In this paper we assess the sensitivity of potential evaporation estimates for different vegetation classes using the two-step approach when calibrated using a non-stationary climate. We used the past century's time series of observed climate, containing non-stationary signals of multi-decadal atmospheric oscillations, global warming, and global dimming/brightening, to evaluate the sensitivity of potential evaporation estimates to the choice and length of the calibration period. We show that using empirical coefficients outside their calibration range may lead to systematic differences between process-based and empirical reference evaporation methods, and systematic errors in estimated potential evaporation components. Such extrapolations of time-variant model parameters are not only relevant for the calculation of potential evaporation, but also for hydrological modeling in general, and they may limit the temporal robustness of hydrological models.

  15. Gravitational memory charges of supertranslation and superrotation on Rindler horizons

    NASA Astrophysics Data System (ADS)

    Hotta, Masahiro; Trevison, Jose; Yamaguchi, Koji

    2016-10-01

    In a Rindler-type coordinate system spanned in a region outside of a black hole horizon, we have nonvanishing classical holographic charges as soft hairs on the horizon for stationary black holes. Taking a large black hole mass limit, the spacetimes with the charges are described by asymptotic Rindler metrics. We construct a general theory of gravitational holographic charges for a (1 +3 )-dimensional linearized gravity field in the Minkowski background with Rindler horizons. Although matter crossing a Rindler horizon causes horizon deformation and a time-dependent coordinate shift—that is, gravitational memory—the supertranslation and superrotation charges on the horizon can be defined during and after its passage through the horizon. It is generally proven that holographic states on the horizon cannot store any information about absorbed perturbative gravitational waves. However, matter crossing the horizon really excites holographic states. By using gravitational memory operators, which consist of the holographic charge operators, we suggest a resolution of the no-cloning paradox of quantum information between matter falling into the horizon and holographic charges on the horizon from the viewpoint of the contextuality of quantum measurement.

  16. Reconstruction of Arctic surface temperature in past 100 years using DINEOF

    NASA Astrophysics Data System (ADS)

    Zhang, Qiyi; Huang, Jianbin; Luo, Yong

    2015-04-01

    Global annual mean surface temperature has not risen apparently since 1998, which is described as global warming hiatus in recent years. However, measuring of temperature variability in Arctic is difficult because of large gaps in coverage of Arctic region in most observed gridded datasets. Since Arctic has experienced a rapid temperature change in recent years that called polar amplification, and temperature risen in Arctic is faster than global mean, the unobserved temperature in central Arctic will result in cold bias in both global and Arctic temperature measurement compared with model simulations and reanalysis datasets. Moreover, some datasets that have complete coverage in Arctic but short temporal scale cannot show Arctic temperature variability for long time. Data Interpolating Empirical Orthogonal Function (DINEOF) were applied to fill the coverage gap of NASA's Goddard Institute for Space Studies Surface Temperature Analysis (GISTEMP 250km smooth) product in Arctic with IABP dataset which covers entire Arctic region between 1979 and 1998, and to reconstruct Arctic temperature in 1900-2012. This method provided temperature reconstruction in central Arctic and precise estimation of both global and Arctic temperature variability with a long temporal scale. Results have been verified by extra independent station records in Arctic by statistical analysis, such as variance and standard deviation. The result of reconstruction shows significant warming trend in Arctic in recent 30 years, as the temperature trend in Arctic since 1997 is 0.76°C per decade, compared with 0.48°C and 0.67°C per decade from 250km smooth and 1200km smooth of GISTEMP. And global temperature trend is two times greater after using DINEOF. The discrepancies above stress the importance of fully consideration of temperature variance in Arctic because gaps of coverage in Arctic cause apparent cold bias in temperature estimation. The result of global surface temperature also proves that

  17. How Earth works 100 years after Wegener's continental drift theory and IGCP 648

    NASA Astrophysics Data System (ADS)

    Li, Z. X.; Evans, D. A.; Zhong, S.; Eglington, B. M.

    2015-12-01

    It took half a century for Wegener's continental drift theory to be accepted as a fundamental element of the plate tectonic theory. Another half a century on, we are still unsure of the driving mechanism for plate tectonics: is it dominated by thermal convection, gravitational forces, or by a combination of mechanisms? Nonetheless, breakthroughs in the past decades put us in a position to make a major stride in answering this question. These include: (1) widely accepted cyclic occurrences of supercontinent assembly and break-up (whereas random occurrence of supercontinents was an equal possibility in the 1990s); (2) the discovery of two equatorial and antipodal large low seismic velocity provinces (LLSVPs) that dominate the lower mantle and appear to have been the base for almost all mantle plumes since at the Mesozoic, and of subduction of oceanic slabs all the way to the core-mantle boundary, which together suggesting whole-mantle convection; (3) the recognition of true polar wander (TPW) as an important process in Earth history, likely reflecting Earth's major internal mass redistribution events; and (4) rapidly enhancing computer modelling power enabling us to simulate all aspect of Earth's dynamic inner working. Many new yet often controversial ideas have been proposed, such a possible coupling in time (with an offset) and space between supercontinent cycle and superplume (LLSVP) events which oppose to the idea of static and long-lived LLSVPs, and the orthoversion v.s. introversion or extroversion models for supercontinent transition. To fully utilise these advances as well as the rapidly expanding global geoscience databases to address the question of how Earth works, an UNESCO-IUGS sponsored IGCP project No. 648 was formed to coordinate a global cross-disciplinary effort. We aim to achieve a better understanding of the supercontinent cycle, and examine the relationship between supercontinent cycle and global plume events. We will establish a series of global

  18. Sensitivity of potential evaporation estimates to 100 years of climate variability

    NASA Astrophysics Data System (ADS)

    Bartholomeus, Ruud; Stagge, James; Tallaksen, Lena; Witte, Jan-Philip

    2015-04-01

    Evaporation from the vegetated surface is the largest loss term in many, if not the most, water balance studies on earth. As a consequence, an accurate representation of evaporation fluxes is required for appropriate quantification of surface runoff, the soil moisture budget, transpiration, recharge and groundwater processes. However, despite being a key component of the water balance, evaporation figures are usually associated with large uncertainties, as this term is difficult to measure or estimate by modeling. Many modeling frameworks have used the concept of potential evaporation, often estimated for different vegetation classes by multiplying the evaporation from a reference surface ('reference evaporation') with crop specific scaling factors ('crop factors'). Though this two-step potential evaporation approach undoubtedly has practical advantages, the empirical nature of both reference evaporation methods and crop factors limits its usability in extrapolations under non-stationary climatic conditions. We quantified the sensitivity of potential evaporation estimates for different vegetation classes using the two-step approach when calibrated using a non-stationary climate. We used the past century's time series of observed climate, containing non-stationary signals of multi-decadal atmospheric oscillations, global warming, and global dimming/brightening, to evaluate the sensitivity of potential evaporation estimates to the choice and length of the calibration period. We show that using empirical coefficients outside their calibration range may lead to systematic differences between process-based and empirical reference evaporation methods, and systematic errors in estimated potential evaporation components. Our hydrological models are to varying extent regression models, which limits their general applicability, and the estimation of potential evaporation is closely linked to climate variability. With our analysis, we want to raise awareness and to provide a

  19. [100 years of drinking water regulation. Retrospective review, current situation and prospects].

    PubMed

    Rakhmanin, Yu A; Krasovsky, G N; Egorova, N A; Mikhailova, R I

    2014-01-01

    There is considered the history of the development of legislative requirements to the regulation of the quality of drinking water in different countries and international organizations during the period from 1912 to the present time. In terms of comparative analysis there is analyzed the current state of regulatory frameworks of the Russian Federation, WHO, EU, Finland, the UK, Singapore, Australia, Japan, China, Nigeria, the United States and Canada in the field of providing favorable conditions of population drinking water use. There has been noted the significant progress in standardization of the content of the biogenic elements and chemical pollution of drinking water in the absence of uniform requirements to the composition and properties of drinking water globally, that is bound to the need to take into account the national peculiarities of drinking water supply within the separate countries. As promising directions for improving regulation of drinking water quality there are noted: the development of new standards for prioritized water pollution, periodic review ofstandards after appearance of the new scientific data on the biological action of substances, the use of the concept of risk, the harmonization of the normative values and the assessment of the possibility of introduction into the practice the one more criterion of profitableness of population water use--the bioenergetic state of the water.

  20. 100 years of training and development research: What we know and where we should go.

    PubMed

    Bell, Bradford S; Tannenbaum, Scott I; Ford, J Kevin; Noe, Raymond A; Kraiger, Kurt

    2017-03-01

    Training and development research has a long tradition within applied psychology dating back to the early 1900s. Over the years, not only has interest in the topic grown but there have been dramatic changes in both the science and practice of training and development. In the current article, we examine the evolution of training and development research using articles published in the Journal of Applied Psychology (JAP) as a primary lens to analyze what we have learned and to identify where future research is needed. We begin by reviewing the timeline of training and development research in JAP from 1918 to the present in order to elucidate the critical trends and advances that define each decade. These trends include the emergence of more theory-driven training research, greater consideration of the role of the trainee and training context, examination of learning that occurs outside the classroom, and understanding training's impact across different levels of analysis. We then examine in greater detail the evolution of 4 key research themes: training criteria, trainee characteristics, training design and delivery, and the training context. In each area, we describe how the focus of research has shifted over time and highlight important developments. We conclude by offering several ideas for future training and development research. (PsycINFO Database Record

  1. Sensitivity of potential evaporation estimates to 100 years of climate variability

    NASA Astrophysics Data System (ADS)

    Bartholomeus, R. P.; Stagge, J. H.; Tallaksen, L. M.; Witte, J. P. M.

    2015-02-01

    Hydrological modeling frameworks require an accurate representation of evaporation fluxes for appropriate quantification of, e.g., the water balance, soil moisture budget, recharge and groundwater processes. Many frameworks have used the concept of potential evaporation, often estimated for different vegetation classes by multiplying the evaporation from a reference surface ("reference evaporation") by crop-specific scaling factors ("crop factors"). Though this two-step potential evaporation approach undoubtedly has practical advantages, the empirical nature of both reference evaporation methods and crop factors limits its usability in extrapolations under non-stationary climatic conditions. In this paper, rather than simply warning about the dangers of extrapolation, we quantify the sensitivity of potential evaporation estimates for different vegetation classes using the two-step approach when calibrated using a non-stationary climate. We used the past century's time series of observed climate, containing non-stationary signals of multi-decadal atmospheric oscillations, global warming, and global dimming/brightening, to evaluate the sensitivity of potential evaporation estimates to the choice and length of the calibration period. We show that using empirical coefficients outside their calibration range may lead to systematic differences between process-based and empirical reference evaporation methods, and systematic errors in estimated potential evaporation components. Quantification of errors provides a possibility to correct potential evaporation calculations and to rate them for their suitability to model climate conditions that differ significantly from the historical record, so-called no-analog climate conditions.

  2. Turnover of Species and Guilds in Shrub Spider Communities in a 100-Year Postlogging Forest Chronosequence.

    PubMed

    Haraguchi, Takashi F; Tayasu, Ichiro

    2016-02-01

    Disturbance of forests by logging and subsequent forest succession causes marked changes in arthropod communities. Although vegetation cover provides important habitat for arthropods, studies of the changes in their community structure associated with forest succession have been conducted mostly at ground level. To evaluate how forests of different ages contribute to arthropod biodiversity in shrub habitat, spiders were collected from shrubs in 12 forests ranging in age from 1 to 107 yr after logging. We found marked changes in spider community structure about 10 yr after logging: the number of species and individuals declined rapidly after this time. These changes were likely caused by a decrease in shrub cover in association with forest succession. Changes in spider species composition associated with stand age were small in forests at least 11 yr old and were not clustered by forest age. After the exclusion of species of which we sampled only one or two individuals incidentally, just 0.9 ± 0.5 (mean ± SD) species were unique to these older forests. The other 41.2 ± 4.3 species found in these forests were common to both older and young forests, although some of these species in common were found mainly in forests at least 11 yr old. These results suggest that preservation of old-growth forests contributes to the abundance of these common species, although old-growth forests contribute little to species diversity.

  3. Cesare Lombroso and epilepsy 100 years later: an unabridged report of his original transactions.

    PubMed

    Monaco, Francesco; Mula, Marco

    2011-04-01

    Cesare Lombroso (1835-1909) still represents one of the most famous and, at the same time, controversial figures of neuropsychiatry. His idea of the "atavist" criminal, prisoner of his/her biologic inheritance, became extremely popular in Western countries. Unfortunately, Lombroso's theory of a strict connection between epilepsy and the criminal personality exerted a long-lasting negative influence on both medical and public opinion, and strongly contributed to the stigmatization of patients with epilepsy. In this report, we aim to present the complete and unabridged series of passages of Cesare Lombroso's works, published only in the Italian language, discussing the issue of epilepsy and crime. All original Italian quotations are offered and an English translation is provided. Although we believe that the medical profession must be well aware of the "evil" distortions generated by Lombrosian theories, which clearly emerge from his original transactions, any comment is deliberately avoided because, in our opinion, people and their ideas must be judged in accordance with the historical period to which they belonged.

  4. [100 years roentgen rays--a discovery conquers the medical world].

    PubMed

    Freybott, A

    1995-11-01

    In the second half of the nineteenth century the prerequisites for research on the discharge of electricity in gases and the related phenomena were fulfilled. The first gas discharge tubes are associated with names like GeiBler, Hittorf, Crookes, Goldstein, Lenard and Hertz. These researchers studied the electrons escaping from the cathode, magnetic and electrical influence, chemical results, loss of energy and heating up of the anode. Lenard and Jackson were the first to describe phenomena outside the tube, but related the effects to electrons. It was W.C. Roentgen who discovered the ¿unknown rays¿; he systematically measured their penetrating properties and described them a short time thereafter. The scientific world was ready for this discovery, and the new of Roentgen's findings spread across the world in a matter of days, followed by intensive development of this innovation. The first and most important 35 years of development of the different types of X-rays tubes are described.

  5. 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).

  6. Accumulation of Pharmaceuticals, Enterococcus, and Resistance Genes in Soils Irrigated with Wastewater for Zero to 100 Years in Central Mexico

    PubMed Central

    Siebe, Christina; Willaschek, Elisha; Sakinc, Tuerkan; Huebner, Johannes; Amelung, Wulf; Grohmann, Elisabeth; Siemens, Jan

    2012-01-01

    Irrigation with wastewater releases pharmaceuticals, pathogenic bacteria, and resistance genes, but little is known about the accumulation of these contaminants in the environment when wastewater is applied for decades. We sampled a chronosequence of soils that were variously irrigated with wastewater from zero up to 100 years in the Mezquital Valley, Mexico, and investigated the accumulation of ciprofloxacin, enrofloxacin, sulfamethoxazole, trimethoprim, clarithromycin, carbamazepine, bezafibrate, naproxen, diclofenac, as well as the occurrence of Enterococcus spp., and sul and qnr resistance genes. Total concentrations of ciprofloxacin, sulfamethoxazole, and carbamazepine increased with irrigation duration reaching 95% of their upper limit of 1.4 µg/kg (ciprofloxacin), 4.3 µg/kg (sulfamethoxazole), and 5.4 µg/kg (carbamazepine) in soils irrigated for 19–28 years. Accumulation was soil-type-specific, with largest accumulation rates in Leptosols and no time-trend in Vertisols. Acidic pharmaceuticals (diclofenac, naproxen, bezafibrate) were not retained and thus did not accumulate in soils. We did not detect qnrA genes, but qnrS and qnrB genes were found in two of the irrigated soils. Relative concentrations of sul1 genes in irrigated soils were two orders of magnitude larger (3.15×10−3±0.22×10−3 copies/16S rDNA) than in non-irrigated soils (4.35×10−5±1.00×10−5 copies/16S rDNA), while those of sul2 exceeded the ones in non-irrigated soils still by a factor of 22 (6.61×10–4±0.59×10−4 versus 2.99×10−5±0.26×10−5 copies/16S rDNA). Absolute numbers of sul genes continued to increase with prolonging irrigation together with Enterococcus spp. 23S rDNA and total 16S rDNA contents. Increasing total concentrations of antibiotics in soil are not accompanied by increasing relative abundances of resistance genes. Nevertheless, wastewater irrigation enlarges the absolute concentration of resistance genes in soils due to a long-term increase in

  7. Accumulation of pharmaceuticals, Enterococcus, and resistance genes in soils irrigated with wastewater for zero to 100 years in central Mexico.

    PubMed

    Dalkmann, Philipp; Broszat, Melanie; Siebe, Christina; Willaschek, Elisha; Sakinc, Tuerkan; Huebner, Johannes; Amelung, Wulf; Grohmann, Elisabeth; Siemens, Jan

    2012-01-01

    Irrigation with wastewater releases pharmaceuticals, pathogenic bacteria, and resistance genes, but little is known about the accumulation of these contaminants in the environment when wastewater is applied for decades. We sampled a chronosequence of soils that were variously irrigated with wastewater from zero up to 100 years in the Mezquital Valley, Mexico, and investigated the accumulation of ciprofloxacin, enrofloxacin, sulfamethoxazole, trimethoprim, clarithromycin, carbamazepine, bezafibrate, naproxen, diclofenac, as well as the occurrence of Enterococcus spp., and sul and qnr resistance genes. Total concentrations of ciprofloxacin, sulfamethoxazole, and carbamazepine increased with irrigation duration reaching 95% of their upper limit of 1.4 µg/kg (ciprofloxacin), 4.3 µg/kg (sulfamethoxazole), and 5.4 µg/kg (carbamazepine) in soils irrigated for 19-28 years. Accumulation was soil-type-specific, with largest accumulation rates in Leptosols and no time-trend in Vertisols. Acidic pharmaceuticals (diclofenac, naproxen, bezafibrate) were not retained and thus did not accumulate in soils. We did not detect qnrA genes, but qnrS and qnrB genes were found in two of the irrigated soils. Relative concentrations of sul1 genes in irrigated soils were two orders of magnitude larger (3.15 × 10(-3) ± 0.22 × 10(-3) copies/16S rDNA) than in non-irrigated soils (4.35 × 10(-5)± 1.00 × 10(-5) copies/16S rDNA), while those of sul2 exceeded the ones in non-irrigated soils still by a factor of 22 (6.61 × 10(-4) ± 0.59 × 10(-4) versus 2.99 × 10(-5) ± 0.26 × 10(-5) copies/16S rDNA). Absolute numbers of sul genes continued to increase with prolonging irrigation together with Enterococcus spp. 23S rDNA and total 16S rDNA contents. Increasing total concentrations of antibiotics in soil are not accompanied by increasing relative abundances of resistance genes. Nevertheless, wastewater irrigation enlarges the absolute concentration of resistance genes in soils due to a long

  8. 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

  9. Novel Cauchy-horizon instability

    SciTech Connect

    Maeda, Hideki; Torii, Takashi; Harada, Tomohiro

    2005-03-15

    The evolution of weak discontinuity is investigated on horizons in the n-dimensional static solutions in the Einstein-Maxwell-scalar-{lambda} system, including the Reissner-Nordstroem-(anti) de Sitter black hole. The analysis is essentially local and nonlinear. We find that the Cauchy horizon is unstable, whereas both the black hole event horizon and the cosmological event horizon are stable. This new instability, the so-called kink instability, of the Cauchy horizon is completely different from the well-known 'infinite-blueshift' instability. The kink instability makes the analytic continuation beyond the Cauchy horizon unstable.

  10. 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.

  11. Horizon as critical phenomenon

    NASA Astrophysics Data System (ADS)

    Lee, Sung-Sik

    2016-09-01

    We show that renormalization group flow can be viewed as a gradual wave function collapse, where a quantum state associated with the action of field theory evolves toward a final state that describes an IR fixed point. The process of collapse is described by the radial evolution in the dual holographic theory. If the theory is in the same phase as the assumed IR fixed point, the initial state is smoothly projected to the final state. If in a different phase, the initial state undergoes a phase transition which in turn gives rise to a horizon in the bulk geometry. We demonstrate the connection between critical behavior and horizon in an example, by deriving the bulk metrics that emerge in various phases of the U( N ) vector model in the large N limit based on the holographic dual constructed from quantum renormalization group. The gapped phase exhibits a geometry that smoothly ends at a finite proper distance in the radial direction. The geometric distance in the radial direction measures a complexity: the depth of renormalization group transformation that is needed to project the generally entangled UV state to a direct product state in the IR. For gapless states, entanglement persistently spreads out to larger length scales, and the initial state can not be projected to the direct product state. The obstruction to smooth projection at charge neutral point manifests itself as the long throat in the anti-de Sitter space. The Poincare horizon at infinity marks the critical point which exhibits a divergent length scale in the spread of entanglement. For the gapless states with non-zero chemical potential, the bulk space becomes the Lifshitz geometry with the dynamical critical exponent two. The identification of horizon as critical point may provide an explanation for the universality of horizon. We also discuss the structure of the bulk tensor network that emerges from the quantum renormalization group.

  12. Towards a robust calving and melt-history for Helheim Glacier, SE Greenland, for the last 100 years

    NASA Astrophysics Data System (ADS)

    Andersen, T. J.; Ellegaard, M.; Markussen, T. N.

    2013-12-01

    Observations of increased ice-discharge from tidewater glaciers in Greenland in the early and mid 2000s has led to concern about a possible rapid loss of ice from the ice sheet in a scenario with increasing air and ocean water temperatures. In order to evaluate the strength and uniqueness of the observed increase a robust data-set on the temporal variation of calving and melt is strongly needed. The only reliable data prior to the period of aerial photographs and instrumental observations is the archive preserved at the seabed in the fjords and coastal waters off the ice sheet. Establishment of core-chronology is central in studies of these archives and is based on Pb-210 dating which will reach approx. 100 years back in time. Establishment of a detailed and accurate core-chronology by means of Pb-210 dating and Cs-137 peaks is by no means a trivial task in environments influenced by episodic deposition of ice-rafted debris (IRD). The deposition will have a relatively large component of random variability which could be mistaken for actual changes in sedimentation rate, especially so if only one or a few cores are analyzed. To increase the reliability of the calving reconstruction, a total of 13 cores have been sampled in this study in Sermilik Fjord in August 2012 at depths between approximately 700 to 900 m. Eleven of the cores are from within the central basin north of 66 degrees North and two are from the outer part of the fjord south of that line. CTD-profiles and measurements of floc size in situ indicate that the sedimentation is significantly influenced by deposition of IRD and temporal changes in sediment accumulation rates will therefore be examined for all the cores. The cores are also being analyzed for their content of dinoflagellate cysts and diatoms in order to examine possible temporal changes in ocean water temperature in the fjord. So far (August 2013) six cores have been studied and the total average accumulation rate for each year since 1925 has

  13. A model to evaluate 100-year energy mix scenarios to facilitate deep decarbonization in the southeastern United States

    SciTech Connect

    Adkisson, Mary A.; Qualls, A. L.

    2016-08-01

    The Southeast United States consumes approximately one billion megawatt-hours of electricity annually; roughly two-thirds from carbon dioxide (CO2) emitting sources. The balance is produced by non-CO2 emitting sources: nuclear power, hydroelectric power, and other renewables. Approximately 40% of the total CO2 emissions come from the electric grid. The CO2 emitting sources, coal, natural gas, and petroleum, produce approximately 372 million metric tons of CO2 annually. The rest is divided between the transportation sector (36%), the industrial sector (20%), the residential sector (3%), and the commercial sector (2%). An Energy Mix Modeling Analysis (EMMA) tool was developed to evaluate 100-year energy mix strategies to reduce CO2 emissions in the southeast. Current energy sector data was gathered and used to establish a 2016 reference baseline. The spreadsheet-based calculation runs 100-year scenarios based on current nuclear plant expiration dates, assumed electrical demand changes from the grid, assumed renewable power increases and efficiency gains, and assumed rates of reducing coal generation and deployment of new nuclear reactors. Within the model, natural gas electrical generation is calculated to meet any demand not met by other sources. Thus, natural gas is viewed as a transitional energy source that produces less CO2 than coal until non-CO2 emitting sources can be brought online. The annual production of CO2 and spent nuclear fuel and the natural gas consumed are calculated and summed. A progression of eight preliminary scenarios show that nuclear power can substantially reduce or eliminate demand for natural gas within 100 years if it is added at a rate of only 1000 MWe per year. Any increases in renewable energy or efficiency gains can offset the need for nuclear power. However, using nuclear power to reduce CO2 will result in significantly more

  14. Estimated 100-year peak flows and flow volumes in the Big Lost River and Birch Creek at the Idaho National Engineering Laboratory, Idaho

    SciTech Connect

    Kjelstrom, L.C.; Berenbrock, C.

    1996-12-31

    The purpose of this report is to provide estimates of the 100-year peak flows and flow volumes that could enter the INEL area from the Big Lost River and Brich Creek are needed as input data for models that will be used to delineate the extent of the 100-year flood plain at the INEL. The methods, procedures and assumptions used to estimate the 100-year peak flows and flow volumes are described in this report.

  15. A 100 year sedimentary record of heavy metal pollution in a shallow eutrophic lake, Lake Chaohu, China.

    PubMed

    Zan, Fengyu; Huo, Shouliang; Xi, Beidou; Su, Jing; Li, Xiang; Zhang, Jingtian; Yeager, Kevin M

    2011-10-01

    This study has worked on the evaluation of the temporal and spatial evolution of heavy metal contamination in sediment taken from a shallow eutrophic lake, Lake Chaohu, China, over the last 100 years, and thereby used (137)Cs and (210)Pb dating, a PIRLA procedure, statistical analysis, geochemical normalization and a enrichment factor calculation (EF). Concentrations of 5174, 29 325, 10.7, 36.4, 20.4, 386.0, 21.1 and 38.4 mg kg(-1) for Ti, Fe, Co, Cr, Cu, Mn, Pb and Zn, respectively, are proposed as natural background values for the Lake Chaohu based on a PIRLA procedure. The contamination history from the last 100 years can be divided into two periods. Before the 1960s, heavy metal contamination did not occur and there was no spatial difference for heavy metal distribution. Since the 1960s, heavy metal enrichment and contamination has occurred, and the west half of the lake region showed a higher degree of contamination than the east half to various intensified anthropogenic activities. In the east half of the lake region, the anthropogenic source of heavy metals mainly originated from agricultural intensification, whereas in the west half of the lake it originated from city runoff and industry as well as agriculture. In all anthropogenic heavy metals, Co is only from industry.

  16. The need for environmental horizon scanning.

    PubMed

    Sutherland, William J; Woodroof, Harry J

    2009-10-01

    Policymakers and practitioners in most fields, including conservation and the environment, often make decisions based on insufficient evidence. One reason for this is that issues appear unexpectedly, when with hindsight, many of them were foreseeable. A solution to the problem of being insufficiently prepared is routine horizon scanning, which we describe as the systematic search for potential threats and opportunities that are currently poorly recognized. Researchers can then decide which issues might be most worthwhile to study. Practitioners can also use horizon scanning to ensure timely policy development and research procurement. Here, we suggest that horizon scanning is an underused tool that should become a standard element of environmental and conservation practice. We make recommendations for its incorporation into research, policy and practice. We argue that, as an ecological and conservation community, we are failing to provide timely advice owing to a weakness in identifying forthcoming issues. We outline possible horizon-scanning methods, and also make recommendations as to how horizon scanning could have a more central role in environmental and conservation practice.

  17. Isolated and dynamical horizons from a common perspective

    SciTech Connect

    Korzynski, Mikolaj

    2006-11-15

    A framework is developed in which one can write down the constraint equations on a three-dimensional hypersurface of arbitrary signature. It is then applied to isolated and dynamical horizons. The derived equations can be used to extract physically relevant quantities describing the horizon irrespective to whether it is isolated (null) or dynamical at a given instant of time. Furthermore, a small perturbation of isolated horizons are considered, and finally a family of an axially symmetric exact solution of the constraint equations on a dynamical horizon is presented.

  18. Horizons of cybernetical physics

    NASA Astrophysics Data System (ADS)

    Fradkov, Alexander L.

    2017-03-01

    The subject and main areas of a new research field-cybernetical physics-are discussed. A brief history of cybernetical physics is outlined. The main areas of activity in cybernetical physics are briefly surveyed, such as control of oscillatory and chaotic behaviour, control of resonance and synchronization, control in thermodynamics, control of distributed systems and networks, quantum control. This article is part of the themed issue 'Horizons of cybernetical physics'.

  19. Horizons of cybernetical physics

    PubMed Central

    2017-01-01

    The subject and main areas of a new research field—cybernetical physics—are discussed. A brief history of cybernetical physics is outlined. The main areas of activity in cybernetical physics are briefly surveyed, such as control of oscillatory and chaotic behaviour, control of resonance and synchronization, control in thermodynamics, control of distributed systems and networks, quantum control. This article is part of the themed issue ‘Horizons of cybernetical physics’. PMID:28115620

  20. 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.

  1. Effects of 100 years wastewater irrigation on resistance genes, class 1 integrons and IncP-1 plasmids in Mexican soil

    PubMed Central

    Jechalke, Sven; Broszat, Melanie; Lang, Friederike; Siebe, Christina; Smalla, Kornelia; Grohmann, Elisabeth

    2015-01-01

    Long-term irrigation with untreated wastewater can lead to an accumulation of antibiotic substances and antibiotic resistance genes in soil. However, little is known so far about effects of wastewater, applied for decades, on the abundance of IncP-1 plasmids and class 1 integrons which may contribute to the accumulation and spread of resistance genes in the environment, and their correlation with heavy metal concentrations. Therefore, a chronosequence of soils that were irrigated with wastewater from 0 to 100 years was sampled in the Mezquital Valley in Mexico in the dry season. The total community DNA was extracted and the absolute and relative abundance (relative to 16S rRNA genes) of antibiotic resistance genes (tet(W), tet(Q), aadA), class 1 integrons (intI1), quaternary ammonium compound resistance genes (qacE+qacEΔ1) and IncP-1 plasmids (korB) were quantified by real-time PCR. Except for intI1 and qacE+qacEΔ1 the abundances of selected genes were below the detection limit in non-irrigated soil. Confirming the results of a previous study, the absolute abundance of 16S rRNA genes in the samples increased significantly over time (linear regression model, p < 0.05) suggesting an increase in bacterial biomass due to repeated irrigation with wastewater. Correspondingly, all tested antibiotic resistance genes as well as intI1 and korB significantly increased in abundance over the period of 100 years of irrigation. In parallel, concentrations of the heavy metals Zn, Cu, Pb, Ni, and Cr significantly increased. However, no significant positive correlations were observed between the relative abundance of selected genes and years of irrigation, indicating no enrichment in the soil bacterial community due to repeated wastewater irrigation or due to a potential co-selection by increasing concentrations of heavy metals. PMID:25784901

  2. Effects of 100 years wastewater irrigation on resistance genes, class 1 integrons and IncP-1 plasmids in Mexican soil.

    PubMed

    Jechalke, Sven; Broszat, Melanie; Lang, Friederike; Siebe, Christina; Smalla, Kornelia; Grohmann, Elisabeth

    2015-01-01

    Long-term irrigation with untreated wastewater can lead to an accumulation of antibiotic substances and antibiotic resistance genes in soil. However, little is known so far about effects of wastewater, applied for decades, on the abundance of IncP-1 plasmids and class 1 integrons which may contribute to the accumulation and spread of resistance genes in the environment, and their correlation with heavy metal concentrations. Therefore, a chronosequence of soils that were irrigated with wastewater from 0 to 100 years was sampled in the Mezquital Valley in Mexico in the dry season. The total community DNA was extracted and the absolute and relative abundance (relative to 16S rRNA genes) of antibiotic resistance genes (tet(W), tet(Q), aadA), class 1 integrons (intI1), quaternary ammonium compound resistance genes (qacE+qacEΔ1) and IncP-1 plasmids (korB) were quantified by real-time PCR. Except for intI1 and qacE+qacEΔ1 the abundances of selected genes were below the detection limit in non-irrigated soil. Confirming the results of a previous study, the absolute abundance of 16S rRNA genes in the samples increased significantly over time (linear regression model, p < 0.05) suggesting an increase in bacterial biomass due to repeated irrigation with wastewater. Correspondingly, all tested antibiotic resistance genes as well as intI1 and korB significantly increased in abundance over the period of 100 years of irrigation. In parallel, concentrations of the heavy metals Zn, Cu, Pb, Ni, and Cr significantly increased. However, no significant positive correlations were observed between the relative abundance of selected genes and years of irrigation, indicating no enrichment in the soil bacterial community due to repeated wastewater irrigation or due to a potential co-selection by increasing concentrations of heavy metals.

  3. The History of Parenting Practices: An Overview! Events, Policies and Theories That Have Influenced Parenting Practices over the Last 100 Years. [Videotape and Worksheets].

    ERIC Educational Resources Information Center

    1999

    Noting that parenting is a learned experience and that the source of information on parenting has changed considerably over the last 100 years, this videotape examines the history of parent education over the past 100 years, highlighting events influencing family life, policies and legislation to assist families, and parenting theories for each…

  4. 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…

  5. Clouds Move Across Mars Horizon

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This sequence combines 32 images of clouds moving eastward across a Martian horizon. The Surface Stereo Imager on NASA's Phoenix Mars Lander took this set of images on Sept. 18, 2008, during early afternoon hours of the 113th Martian day of the mission.

    The view is toward the north. The actual elapsed time between the first image and the last image is nearly half an hour. The numbers inset at lower left are the elapsed time, in seconds, after the first image of the sequence. The particles in the clouds are water-ice, as in cirrus clouds on Earth.

    Phoenix landed in the northern region of Mars on May 25, 2008. The mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  6. Flow and sediment processes in a cutoff meander of the Danube Delta during 100-year recurrent flood

    NASA Astrophysics Data System (ADS)

    Jugaru Tiron, L.; Le Coz, J.; Provansal, M.; Dutu, F.

    2009-04-01

    River training operations, such as meander cutoff, initiated for navigational purposes often lead to dramatic changes in the streamwise profiles (Hooke, 1986, Kesel, 2003; Kiss et al., 2007). Meander correction affects both the hydraulic and morphodynamical behavior of the modified branches that sedimentation occurs in time, while newly built canals usually experience degradation (Jugaru et. al, 2006). This study reports and analyzes new data on the hydrological and sedimentary processes at work during a morphogenic flood in a large modified meander (the Mahmudia meander) of the St. George branch, the southern branch of the Danube Delta. The 100-year recurrent flood that occurred in 2006 offered an exceptional opportunity for scanning different cross sections of the Mahmudia meander system by means of the emerging Doppler profiler (aDcp) technology in order to analyze the impact on sedimentation and dynamic processes in the study area. The Mahmudia study site corresponds to a vast natural meander which was cut off in 1984-1988 by an artificial canal opened to shipping. The meander correction accelerated fluxes through the artificial canal and dramatically enhanced deposition in the former meander. After his formation, the cutoff meander acted as sediment storage locations, essentially removing channel and point bar sediments from the active sediment budget of the main channel (Popa, 1997). During the one-hundred-year recurrent flood in April 2006, bathymetry, flow velocity and discharge data were acquired across several sections of both natural and artificial channels with an acoustic Doppler current profiler (aDcp Workhorse Sentinel 600 kHz, Teledyne RDI) in order to investigate the distribution of the flow and sediment and his impact on sedimentation in a channelized reach and its adjacent cutoff. The contrasting hydro-sedimentary processes at work in both channels and bifurcation/confluence nodal points are analyzed from the measured flux distribution

  7. 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.

  8. What Happens at the Horizon?

    NASA Astrophysics Data System (ADS)

    Mathur, Samir D.

    2013-07-01

    The Schwarzschild metric has an apparent singularity at the horizon r = 2M. What really happens there? If physics at the horizon is "normal" laboratory physics, then we run into Hawking's information paradox. If we want nontrivial structure at the horizon, then we need a mechanism to generate this structure that evades the "no hair" conjectures of the past. Further, if we have such structure, then what would be the role of the traditional black hole metric which continues smoothly past the horizon? Recent work has provided an answer to these questions, and in the process revealed a beautiful tie-up between gravity, string theory and thermodynamics.

  9. 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.

  10. Aboveground and belowground legacies of native Sami land use on boreal forest in northern Sweden 100 years after abandonment.

    PubMed

    Freschet, Grégoire T; Ostlund, Lars; Kichenin, Emilie; Wardle, David A

    2014-04-01

    Human activities that involve land-use change often cause major transformations to community and ecosystem properties both aboveground and belowground, and when land use is abandoned, these modifications can persist for extended periods. However, the mechanisms responsible for rapid recovery vs. long-term maintenance of ecosystem changes following abandonment remain poorly understood. Here, we examined the long-term ecological effects of two remote former settlements, regularly visited for -300 years by reindeer-herding Sami and abandoned -100 years ago, within an old-growth boreal forest that is considered one of the most pristine regions in northern Scandinavia. These human legacies were assessed through measurements of abiotic and biotic soil properties and vegetation characteristics at the settlement sites and at varying distances from them. Low-intensity land use by Sami is characterized by the transfer of organic matter towards the settlements by humans and reindeer herds, compaction of soil through trampling, disappearance of understory vegetation, and selective cutting of pine trees for fuel and construction. As a consequence, we found a shift towards early successional plant species and a threefold increase in soil microbial activity and nutrient availability close to the settlements relative to away from them. These changes in soil fertility and vegetation contributed to 83% greater total vegetation productivity, 35% greater plant biomass, and 23% and 16% greater concentrations of foliar N and P nearer the settlements, leading to a greater quantity and quality of litter inputs. Because decomposer activity was also 40% greater towards the settlements, soil organic matter cycling and nutrient availability were further increased, leading to likely positive feedbacks between the aboveground and belowground components resulting from historic land use. Although not all of the activities typical of Sami have left visible residual traces on the ecosystem after

  11. Empirical correction for earth sensor horizon radiance variation

    NASA Technical Reports Server (NTRS)

    Hashmall, Joseph A.; Sedlak, Joseph; Andrews, Daniel; Luquette, Richard

    1998-01-01

    A major limitation on the use of infrared horizon sensors for attitude determination is the variability of the height of the infrared Earth horizon. This variation includes a climatological component and a stochastic component of approximately equal importance. The climatological component shows regular variation with season and latitude. Models based on historical measurements have been used to compensate for these systematic changes. The stochastic component is analogous to tropospheric weather. It can cause extreme, localized changes that for a period of days, overwhelm the climatological variation. An algorithm has been developed to compensate partially for the climatological variation of horizon height and at least to mitigate the stochastic variation. This method uses attitude and horizon sensor data from spacecraft to update a horizon height history as a function of latitude. For spacecraft that depend on horizon sensors for their attitudes (such as the Total Ozone Mapping Spectrometer-Earth Probe-TOMS-EP) a batch least squares attitude determination system is used. It is assumed that minimizing the average sensor residual throughout a full orbit of data results in attitudes that are nearly independent of local horizon height variations. The method depends on the additional assumption that the mean horizon height over all latitudes is approximately independent of season. Using these assumptions, the method yields the latitude dependent portion of local horizon height variations. This paper describes the algorithm used to generate an empirical horizon height. Ideally, an international horizon height database could be established that would rapidly merge data from various spacecraft to provide timely corrections that could be used by all.

  12. 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…

  13. A 100-year sedimentary record of natural and anthropogenic impacts on a shallow eutrophic lake, Lake Chaohu, China.

    PubMed

    Zan, Fengyu; Huo, Shouliang; Xi, Beidou; Zhu, Chaowei; Liao, Haiqing; Zhang, Jingtian; Yeager, Kevin M

    2012-03-01

    In this study, the sediment profiles of total organic carbon, total nitrogen, C/N ratios, total phosphorus, N/P ratios, C/P ratios, particle sizes, and stable carbon and nitrogen isotopes (δ(13)C and δ(15)N) were used to investigate natural and anthropogenic impacts on Lake Chaohu over the past 100 years. Before 1960, Lake Chaohu experienced low productivity and a relatively steady and low nutrient input. The increasing concentration and fluxes of total organic carbon, total nitrogen, total phosphorus, together with changes in the δ(13)C and δ(15)N of organic material in the sediment cores, suggested that the anthropogenic effects on trophic status first started because of an increase in nutrient input caused by a population increase in the drainage area. With the construction of the Chaohu Dam, an increase in the utilization of fertilizer and the population growth which occurred since 1960, stable depositional conditions and increasing nutrient input resulted in a dominantly algae-derived organic matter source and high productivity. Nutrient input increased most significantly around 1980 following the rapidly growing population, with concomitant urbanization, industrial and agricultural development. This study also revealed that the concentration and distribution of nutrients varied between different areas of sediment within Lake Chaohu because of the influence of different drainage basins and pollution sources.

  14. Regime Shifts in Shallow Lakes: Responses of Cyanobacterial Blooms to Watershed Agricultural Phosphorus Loading Over the Last ~100 Years.

    NASA Astrophysics Data System (ADS)

    Vermaire, J. C.; Taranu, Z. E.; MacDonald, G. K.; Velghe, K.; Bennett, E.; Gregory-Eaves, I.

    2015-12-01

    Rapid changes in ecosystem states have occurred naturally throughout Earth's history. However, environmental changes that have taken place since the start of the Anthropocene may be destabilizing ecosystems and increasing the frequency of regime shifts in response to abrupt changes in external drivers or local intrinsic dynamics. To evaluate the relative influence of these forcers and improve our understanding of the impact of future change, we examined the effects of historical catchment phosphorus loading associated with agricultural land use on lake ecosystems, and whether this caused a shift from a stable, clear-water, regime to a turbid, cyanobacteria-dominated, state. The sedimentary pigments, diatom, and zooplankton (Cladocera) records from a currently clear-water shallow lake (Roxton Pond) and a turbid-water shallow lake (Petit lac Saint-François; PSF) were examined to determine if a cyanobacteria associated pigment (i.e. echinenone) showed an abrupt non-linear response to continued historical phosphorus load index (determined by phosphorus budget) over the last ~100 years. While PSF lake is presently in the turbid-water state, pigment and diatom analyses indicated that both lakes were once in the clear-water state, and that non-linear increases in catchment phosphorus balance resulted in an abrupt transition to cyanobacteria dominated states in each record. These results show that phosphorus loading has resulted in state shifts in shallow lake ecosystems that has been recorded across multiple paleolimnological indicators preserved in the sedimentary record.

  15. DNA from a 100-year-old holotype confirms the validity of a potentially extinct hummingbird species.

    PubMed

    Kirchman, Jeremy J; Witt, Christopher C; McGuire, Jimmy A; Graves, Gary R

    2010-02-23

    We used mtDNA sequence data to confirm that the controversial 100-year-old holotype of the Bogotá sunangel (Heliangelus zusii) represents a valid species. We demonstrate that H. zusii is genetically well differentiated from taxa previously hypothesized to have given rise to the specimen via hybridization. Phylogenetic analyses place H. zusii as sister to a clade of mid- to high-elevation Andean species currently placed in the genera Taphrolesbia and Aglaiocercus. Heliangelus zusii, presumed extinct, has never been observed in nature by biologists. We infer that the species occupied a restricted distribution between the upper tropical and temperate zones of the northern Andes and that it was most probably driven to extinction by deforestation that accompanied human population growth during the nineteenth and early twentieth centuries. We demonstrate the feasibility of obtaining DNA from nearly microscopic tissue samples from old hummingbird specimens and suggest that these methods could be used to resolve the taxonomy of dozens of avian taxa known only from type specimens.

  16. CoSMoS Southern California v3.0 Phase 1 (100-year storm) storm hazard projections

    USGS Publications Warehouse

    Barnard, Patrick; Erikson, Li; Foxgrover, Amy; O'Neill, Andrea; Herdman, Liv

    2016-01-01

    The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of kilometers) of storm-induced coastal flooding and erosion for both current and future sea-level rise (SLR) scenarios. CoSMoS v3.0 for Southern California shows projections for future climate scenarios (sea-level rise and storms) to provide emergency responders and coastal planners with critical storm-hazards information that can be used to increase public safety, mitigate physical damages, and more effectively manage and allocate resources within complex coastal settings. Phase I data for Southern California include flood-hazard information for the coast from the Mexican Border to Pt. Conception for a 100-year storm scenario and sea-level rise 0 - 2 m. Changes from previous data releases may be reflected in some areas. Data are complete for the information presented but are considered preliminary; changes may be reflected in the full data release (Phase II) in summer 2016.

  17. On the Influence of the NAO on Outlet Glacier Stability in SE Greenland during the Past 100 Years

    NASA Astrophysics Data System (ADS)

    Andresen, C. S.

    2014-12-01

    The Greenland Ice sheet has gained massive attention in recent years due to a sudden increase in mass loss at the onset of this century. A significant part of this mass loss has been attributed to increased ice discharge at the margin through iceberg calving from marine-terminating outlet glaciers. However, due to the lack of instrumental data beyond the past 20-30 years it is difficult to evaluate if this was an outstanding event or if it was part of a recurring phenomenon acting on inter-annual, inter-decadal or centennial timescales. In order to improve understanding of the timescales involved in glacier changes and on the influence of ocean and atmosphere variability we investigate sediment archives from fjords with marine terminating glaciers. Near the glacier margin the sedimentation rates are relatively high due to glacial flour input and rafting of iceberg debris. Our studies of several sediment cores obtained from Sermilik Fjord by Helheim Glacier in Southeast Greenland has allowed us to reconstruct glacier calving, shelf temperature and fjord water renewal rate for the past 100 years. These studies show that dominant modes of climate variability, i.e. the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation, affect ocean properties near the glacier and that the recorded variability concurs with reconstructed outlet glacier changes. This presentation provides an overview these studies.

  18. 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.

  19. 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.

  20. 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…

  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. 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…

  3. 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…

  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. 78 FR 70976 - Horizons ETFs Management (USA) LLC and Horizons ETF Trust; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-27

    ... COMMISSION Horizons ETFs Management (USA) LLC and Horizons ETF Trust; Notice of Application November 21, 2013... Shares. Applicants: Horizons ETFs Management (USA) LLC (``Horizons'') and Horizons ETF Trust (``Trust... Commission, 100 F Street NE., Washington, DC 20549-1090; Applicants: Horizons ETFs Management (USA) LLC,...

  6. Acidophilic denitrifiers dominate the N2O production in a 100-year-old tea orchard soil.

    PubMed

    Huang, Ying; Long, Xi-En; Chapman, Stephen J; Yao, Huaiying

    2015-03-01

    Aerobic denitrification is the main process for high N2O production in acid tea field soil. However, the biological mechanisms for the high emission are not fully understood. In this study, we examined N2O emission and denitrifier communities in 100-year-old tea soils with four pH levels (3.71, 5.11, 6.19, and 7.41) and four nitrate concentration (0, 50, 200, and 1000 mg kg(-1) of NO3 (-)-N) addition. Results showed the highest N2O emission (10.1 mg kg(-1) over 21 days) from the soil at pH 3.71 with 1000 mg kg(-1) NO3 (-) addition. The N2O reduction and denitrification enzyme activity in the acid soils (pH <7.0) were significantly higher than that of soils at pH 7.41. Moreover, TRF 78 of nirS and TRF 187 of nosZ dominated in soils of pH 3.71, suggesting an important role of acidophilic denitrifiers in N2O production and reduction. CCA analysis also showed a negative correlation between the dominant denitrifier ecotypes (nirS TRF 78, nosZ TRF 187) and soil pH. The representative sequences were identical to those of cultivated denitrifiers from acidic soils via phylogenetic tree analysis. Our results showed that the acidophilic denitrifier adaptation to the acid environment results in high N2O emission in this highly acidic tea soil.

  7. Falling through the black hole horizon

    NASA Astrophysics Data System (ADS)

    Brustein, Ram; Medved, A. J. M.

    2015-06-01

    We consider the fate of a small classical object, a "stick", as it falls through the horizon of a large black hole (BH). Classically, the equivalence principle dictates that the stick is affected by small tidal forces, and Hawking's quantum-mechanical model of BH evaporation makes essentially the same prediction. If, on the other hand, the BH horizon is surrounded by a "firewall", the stick will be consumed as it falls through. We have recently extended Hawking's model by taking into account the quantum fluctuations of the geometry and the classical back-reaction of the emitted particles. Here, we calculate the train exerted on the falling stick for our model. The strain depends on the near-horizon state of the Hawking pairs. We find that, after the Page time when the state of the pairs deviates significantly from maximal entanglement (as required by unitarity), the induced strain in our semiclassical model is still parametrically small. This is because the number of the disentangled pairs is parametrically smaller than the BH entropy. A firewall does, however, appear if the number of disentangled pairs near the horizon is of order of the BH entropy, as implicitly assumed in previous discussions in the literature.

  8. 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

  9. Asymptotic symmetries on Killing horizons

    NASA Astrophysics Data System (ADS)

    Koga, Jun-Ichirou

    2001-12-01

    We investigate asymptotic symmetries regularly defined on spherically symmetric Killing horizons in Einstein theory with or without the cosmological constant. These asymptotic symmetries are described by asymptotic Killing vectors, along which the Lie derivatives of perturbed metrics vanish on a Killing horizon. We derive the general form of the asymptotic Killing vectors and find that the group of asymptotic symmetries consists of rigid O(3) rotations of a horizon two-sphere and supertranslations along the null direction on the horizon, which depend arbitrarily on the null coordinate as well as the angular coordinates. By introducing the notion of asymptotic Killing horizons, we also show that local properties of Killing horizons are preserved not only under diffeomorphisms but also under nontrivial transformations generated by the asymptotic symmetry group. Although the asymptotic symmetry group contains the Diff(S1) subgroup, which results from supertranslations dependent only on the null coordinate, it is shown that the Poisson brackets algebra of the conserved charges conjugate to asymptotic Killing vectors does not acquire nontrivial central charges. Finally, by considering extended symmetries, we discuss the fact that unnatural reduction of the symmetry group is necessary in order to obtain the Virasoro algebra with nontrivial central charges, which is not justified when we respect the spherical symmetry of Killing horizons.

  10. 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.

  11. 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

  12. 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.

  13. Microbe-mediated transformations of marine dissolved organic matter during 2,100 years of natural incubation in the cold, oxic crust of the Mid-Atlantic Ridge.

    NASA Astrophysics Data System (ADS)

    Shah Walter, S. R.; Jaekel, U.; Huber, J. A.; Dittmar, T.; Girguis, P. R.

    2015-12-01

    On the western flank of the Mid-Atlantic Ridge, oxic seawater from the deep ocean is downwelled into the basaltic crust, supplying the crustal aquifer with an initial inoculum of organic matter and electron acceptors. Studies have shown that fluids circulating within the crust are minimally altered from original seawater, making this subsurface environment a unique natural experiment in which the fate of marine organic matter and the limitations of microbial adaptability in the context of reduced carbon supply can be examined. To make the subsurface crustal aquifer accessible, two CORK (Circulation Obviation Retrofit Kit) observatories have been installed at North Pond, a sediment-filled depression beneath the oligotrophic Sargasso Sea. Radiocarbon analysis of dissolved inorganic (DIC) and organic carbon (DOC) in samples recovered from these observatories show uncoupled aging between DOC and DIC with Δ14C values of DOC as low as -933‰ despite isolation from the open ocean for, at most, 2,100 years. This extreme value is part of a general trend of decreasing DOC δ13C and Δ14C values with increasing incubation time within the aquifer. Combined with reduced concentrations of DOC, our results argue for selective microbial oxidation of the youngest, most 13C-enriched components of downwelled DOC, possibly identifying these as characteristics of the more bioavailable fractions of deep-ocean dissolved organic matter. They also suggest that microbial oxidation during low-temperature hydrothermal circulation could be an important sink for aged marine dissolved organic matter.

  14. Quantum correlations across the black hole horizon

    SciTech Connect

    Schuetzhold, Ralf; Unruh, William G.

    2010-06-15

    Inspired by the condensed-matter analogues of black holes, we study the quantum correlations across the event horizon reflecting the entanglement between the outgoing particles of the Hawking radiation and their in-falling partners. For a perfectly covariant theory, the total correlation is conserved in time and piles up arbitrary close to the horizon in the past, where it merges into the singularity of the vacuum two-point function at the light cone. After modifying the dispersion relation (i.e., breaking Lorentz invariance) for large k, on the other hand, the light cone is smeared out and the entanglement is not conserved but actually created in a given rate per unit time.

  15. 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.

  16. Determination of the 100-year flood plain on Upper Three Runs and selected tributaries, and the Savannah River at the Savannah River site, South Carolina, 1995

    USGS Publications Warehouse

    Lanier, T.H.

    1996-01-01

    The 100-year flood plain was determined for Upper Three Runs, its tributaries, and the part of the Savannah River that borders the Savannah River Site. The results are provided in tabular and graphical formats. The 100-year flood-plain maps and flood profiles provide water-resource managers of the Savannah River Site with a technical basis for making flood-plain management decisions that could minimize future flood problems and provide a basis for designing and constructing drainage structures along roadways. A hydrologic analysis was made to estimate the 100-year recurrence- interval flow for Upper Three Runs and its tributaries. The analysis showed that the well-drained, sandy soils in the head waters of Upper Three Runs reduce the high flows in the stream; therefore, the South Carolina upper Coastal Plain regional-rural-regression equation does not apply for Upper Three Runs. Conse- quently, a relation was established for 100-year recurrence-interval flow and drainage area using streamflow data from U.S. Geological Survey gaging stations on Upper Three Runs. This relation was used to compute 100-year recurrence-interval flows at selected points along the stream. The regional regression equations were applicable for the tributaries to Upper Three Runs, because the soil types in the drainage basins of the tributaries resemble those normally occurring in upper Coastal Plain basins. This was verified by analysis of the flood-frequency data collected from U.S. Geological Survey gaging station 02197342 on Fourmile Branch. Cross sections were surveyed throughout each reach, and other pertinent data such as flow resistance and land-use were col- lected. The surveyed cross sections and computed 100-year recurrence-interval flows were used in a step-backwater model to compute the 100-year flood profile for Upper Three Runs and its tributaries. The profiles were used to delineate the 100-year flood plain on topographic maps. The Savannah River forms the southwestern border

  17. Simulations of the Greenland ice sheet 100 years into the future with the full Stokes model Elmer/Ice

    NASA Astrophysics Data System (ADS)

    Seddik, H.; Greve, R.; Zwinger, T.; Gillet-Chaulet, F.; Gagliardini, O.

    2011-12-01

    the surface precipitation and temperature and the set S (three experiments) applies an amplification factor to change the basal sliding velocity. The experiments are compared to a constant climate control run beginning at present (epoch 2004-1-1 0:0:0) and running up to 100 years holding the climate constant to its present state. The experiments with the amplification factor (Set S) show high sensitivities. Relative to the control run, the scenario with an amplification factor of 3x applied to the sliding velocity produces a Greenland contribution to sea level rise of ~25 cm. An amplification factor of 2.5x produces a contribution of ~16 cm and an amplification factor 2x produces a contribution of ~9 cm. The experiments with the changes to the surface precipitation and temperature (set C) show a contribution to sea level rise of ~4 cm when a factor 1x is applied to the temperature and precipitation anomalies. A factor 1.5x produces a sea level rise of ~8 cm and a factor 2x produces a sea level rise of ~12 cm.

  18. 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

  19. 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.

  20. Water-surface profile and flood boundaries for the computed 100-year flood, Lame Deer Creek, Northern Cheyenne Indian Reservation, Montana

    USGS Publications Warehouse

    Omang, R.J.

    1994-01-01

    Hydrologic and hydraulic evaluations of Lame Deer Creek were made to determine the magnitude of the 100-year flood and the extent of flooding that would occur as the result of this flood. SixtY-six cross sections were Surveyed and 25 cross sections were synthesized along a 9.5-mile reach of Lame Deer Creek. Data from the surveys were used to calculate the water-surface elevation at each cross section using a computer program (WSPRO) developed by the U.S. Geological Survey. The water-surface profile of the computed 100-year flood elevations was then drawn. The profile shows the streambed elevation and the location of the bridge, culverts, and cross sections. The computed 100-year flood elevation at each cross section was used to delineate the width of the flood plain at that section. Flood boundaries between cross sections were interpolated using contour lines on topographic maps.

  1. Dynamical AdS strings across horizons

    SciTech Connect

    Ishii, Takaaki; Murata, Keiju

    2016-03-01

    We examine the nonlinear classical dynamics of a fundamental string in anti-deSitter 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 Poincare´ 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. Lastly, the condition for this transition to occur is that energy injection exceeds the static energy between the quark-antiquark pair.

  2. Dynamical AdS strings across horizons

    DOE PAGES

    Ishii, Takaaki; Murata, Keiju

    2016-03-01

    We examine the nonlinear classical dynamics of a fundamental string in anti-deSitter 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 Poincare´ 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 vanishmore » with a power law whose slope depends on the perturbations. Lastly, the condition for this transition to occur is that energy injection exceeds the static energy between the quark-antiquark pair.« less

  3. 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

  4. 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.

  5. 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.

  6. [100 years ago: Oskar Kreis, a pioneer in spinal obstetric analgesia at the University Women's Clinic of Basel].

    PubMed

    Schneider, M C; Holzgreve, W

    2001-07-01

    In 1900, Oskar Kreis (1872-1958), a gynecologist and obstetrician who received his training at the Basle University Women's Hospital, pioneered the use of spinal anaesthesia in six parturients for labour pain relief. Cocaine was used as a local anaesthetic, which had previously been shown to be effective for spinal anaesthesia by August Bier in 1898. This important advance in anaesthetic care was not widely acknowledged for a long period of time and it has only been during the past few decades that spinal anaesthesia was rediscovered as an important technique available for obstetric anaesthesia.

  7. New 100 + Year Road RALE System With T-Beam Foundation Saves Energy and Increases Safety by Reducing Work Zones

    NASA Astrophysics Data System (ADS)

    Pressler, David

    2007-05-01

    Traffic crashes represents a loss of 2.2 percent of the U.S. Gross Domestic Product a year. By reducing congestion and the number of dangerous construction zones it is possible to increase user safety with fewer accidents. This new system once implemented eliminates many major national road preservation projects, which include replacing or reconstructing the highway pavements over the long period. Other included costs like those of lost time and lost fuel incurred by passenger and freight transportation on the section being reconstructed amount to well over 100 billion dollars a year. All other things being equal, thicker concrete highway pavements will last longer, however, thicker pavement costs more. By utilizing the physics of the T-Beam or the ``floor-joist,'' concept where the upper deck of the highway is supported and reinforced by longitude beams or rails that protrude into the soil, there is a great improvement in the strength of the pavement system. The pavement structure configuration of rails supports and carries vehicle loads, which is transferred ``down-the-road.'' Much like a snowshoe or like a rail bridge this device spreads out the applied stresses over a much larger area and the high strength pavement resists flexing of the concrete. Stress reduction reduces concrete fatigue and this allows the highway to last three to four times as long without major road reconstruction. To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.OSS07.P1.2

  8. NIF featured on BBC "Horizon"

    ScienceCinema

    Brian Cox

    2016-07-12

    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. 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.

  10. 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…

  11. Introduction to the special section on cognitive abilities: 100 years after Spearman's (1904) "'General intelligence,' objectively determined and measured".

    PubMed

    Lubinski, David

    2004-01-01

    The study of individual differences in cognitive abilities is one of the few branches of psychological science to amass a coherent body of empirical knowledge withstanding the test of time. There is wide consensus that cognitive abilities are organized hierarchically, and C. Spearman's (1904) general intelligence occupies the vertex of this hierarchy. In addition, specific abilities beyond general intelligence refine longitudinal forecasts of important social phenomena and paint a rich portrait of this important domain of psychological diversity. This opening article identifies and then reviews 5 major areas concerning the personological significance of cognitive abilities and the methods used to study them. In models of human behavior and important life outcomes, cognitive abilities are critical in more ways than social scientists realize.

  12. 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.

  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. Earth on the Horizon

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This is the first image ever taken of Earth from the surface of a planet beyond the Moon. It was taken by the Mars Exploration Rover Spirit one hour before sunrise on the 63rd martian day, or sol, of its mission. Earth is the tiny white dot in the center. The image is a mosaic of images taken by the rover's navigation camera showing a broad view of the sky, and an image taken by the rover's panoramic camera of Earth. The contrast in the panoramic camera image was increased two times to make Earth easier to see.

  15. Black holes or firewalls: A theory of horizons

    NASA Astrophysics Data System (ADS)

    Nomura, Yasunori; Varela, Jaime; Weinberg, Sean J.

    2013-10-01

    We present a quantum theory of black hole (and other) horizons, in which the standard assumptions of complementarity are preserved without contradicting information theoretic considerations. After the scrambling time, the quantum mechanical structure of a black hole becomes that of an eternal black hole at the microscopic level. In particular, the stretched horizon degrees of freedom and the states entangled with them can be mapped into the near-horizon modes in the two exterior regions of an eternal black hole, whose mass is taken to be that of the evolving black hole at each moment. Salient features arising from this picture include (i) the number of degrees of freedom needed to describe a black hole is eA/2lP2, where A is the area of the horizon; (ii) black hole states having smooth horizons, however, span only an eA/4lP2-dimensional subspace of the relevant eA/2lP2-dimensional Hilbert space; (iii) internal dynamics of the horizon is such that an infalling observer finds a smooth horizon with a probability of 1 if a state stays in this subspace. We identify the structure of local operators responsible for describing semiclassical physics in the exterior and interior spacetime regions and show that this structure avoids the arguments for firewalls—the horizon can keep being smooth throughout the evolution. We discuss the fate of infalling observers under various circumstances, especially when the observers manipulate degrees of freedom before entering the horizon, and we find that an observer can never see a firewall by making a measurement on early Hawking radiation. We also consider the presented framework from the viewpoint of an infalling reference frame and argue that Minkowski-like vacua are not unique. In particular, the number of true Minkowski vacua is infinite, although the label discriminating these vacua cannot be accessed in usual nongravitational quantum field theory. An application of the framework to de Sitter horizons is also discussed.

  16. 100 years of radionuclide metrology.

    PubMed

    Judge, S M; Arnold, D; Chauvenet, B; Collé, R; De Felice, P; García-Toraño, E; Wätjen, U

    2014-05-01

    The discipline of radionuclide metrology at national standards institutes started in 1913 with the certification by Curie, Rutherford and Meyer of the first primary standards of radium. In early years, radium was a valuable commodity and the aim of the standards was largely to facilitate trade. The focus later changed to providing standards for the new wide range of radionuclides, so that radioactivity could be used for healthcare and industrial applications while minimising the risk to patients, workers and the environment. National measurement institutes responded to the changing demands by developing new techniques for realising primary standards of radioactivity. Looking ahead, there are likely to be demands for standards for new radionuclides used in nuclear medicine, an expansion of the scope of the field into quantitative imaging to facilitate accurate patient dosimetry for nuclear medicine, and an increasing need for accurate standards for radioactive waste management and nuclear forensics.

  17. Celebrating 100 Years of Flight.

    ERIC Educational Resources Information Center

    Reese, Susan

    2003-01-01

    In honor of the Wright brothers' first flight, the article profiles aviation and aerospace technology programs that are training workers in aviation safety and explorations. Looks at programs from Eastern New Mexico University-Roswell, Pima Community College, and Olathe Northwest High School. (JOW)

  18. 100 Years of Reality Learning

    ERIC Educational Resources Information Center

    Zimpher, Nancy L.; Wright Ron, D.

    2006-01-01

    One may have heard of reality TV, but what about reality learning? The latter is probably a term one hasn't seen much, although it is in many ways a clearer and more concise name for a concept that in 2006 marks its 100th anniversary: cooperative education, or "co-op." Co-op, a break-through idea pioneered at the University of Cincinnati by Herman…

  19. Pair production close to black hole horizon

    NASA Astrophysics Data System (ADS)

    Laurent, Philippe; Titarchuk, Lev

    2012-07-01

    Accreting stellar-mass black holes in Galactic binaries exhibit a ``bi-modal" spectral behavior - namely the so called high-soft and low-hard spectral states. An increase in the soft blackbody luminosity component leads to the appearance of an extended power law. An important observational fact is that this effect is seen as a persistent phenomenon only in BH candidates, and thus it is apparently a unique black hole signature. Although similar power law components are detected in the intermediate stages in neutron star systems, they are of a transient nature, i.e. disappearing with increasing luminosity. It thus seems a reasonable assumption that the unique spectral signature of the soft state of BH binaries is directly tied to the black hole event horizon. This is the primary motivation for the Bulk Motion Comptonization Model, introduced in several previous papers, and recently applied with striking success to a substantial body of observational data. We argued that the BH X-ray spectrum in the high-soft state is formed in the relatively cold accretion flow with a subrelativistic bulk velocity close to c and a temperature of a few keV. In such a flow the effect of the bulk Comptonization is indeed much stronger than the effect of the thermal ones. Another property of these accreted flow, that we will explore during this talk, is that, very close to horizon, X-ray photons may be upscattered by bulk electrons to MeV energy. Most of these photons fall down then in the black hole, but some of them anyway have time to interact with another X-ray photon by the photon-photon process to make an electron-positron pairs. We will then explore in details the consequences of this pair creation process close to horizon and what can be the observational evidences of this effect.

  20. 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.

  1. Toroidal horizons in binary black hole mergers

    NASA Astrophysics Data System (ADS)

    Bohn, Andy; Kidder, Lawrence E.; Teukolsky, Saul A.

    2016-09-01

    We find the first binary black hole event horizon with a toroidal topology. It has been predicted that generically the event horizons of merging black holes should briefly have a toroidal topology. However, such a phase has never been seen in numerical simulations. Instead, in all previous simulations, the topology of the event horizon transitions directly from two spheres during the inspiral to a single sphere as the black holes merge. We find a coordinate transformation to a foliation of spacelike hypersurfaces that "cut a hole" through the event horizon surface, resulting in a toroidal event horizon, thus reconciling the numerical work with theoretical expectations. The demonstration requires extremely high numerical precision, which is made possible by a new event horizon code described in a companion paper. A torus could potentially provide a mechanism for violating topological censorship. However, these toroidal event horizons satisfy topological censorship by construction, because we can always trivially apply the inverse coordinate transformation to remove the topological feature.

  2. Simulation of water-surface elevations for a hypothetical 100-year peak flow in Birch Creek at the Idaho National Engineering and Environmental Laboratory, Idaho

    SciTech Connect

    Berenbrock, C.; Kjelstrom, L.C.

    1997-10-01

    Delineation of areas at the Idaho National Engineering and Environmental Laboratory that would be inundated by a 100-year peak flow in Birch Creek is needed by the US Department of Energy to fulfill flood-plain regulatory requirements. Birch Creek flows southward about 40 miles through an alluvium-filled valley onto the northern part of the Idaho National Engineering and Environmental laboratory site on the eastern Snake River Plain. The lower 10-mile reach of Birch Creek that ends in Birch Creek Playa near several Idaho National Engineering and Environmental Laboratory facilities is of particular concern. Twenty-six channel cross sections were surveyed to develop and apply a hydraulic model to simulate water-surface elevations for a hypothetical 100-year peak flow in Birch Creek. Model simulation of the 100-year peak flow (700 cubic feet per second) in reaches upstream from State Highway 22 indicated that flow was confined within channels even when all flow was routed to one channel. Where the highway crosses Birch Creek, about 315 cubic feet per second of water was estimated to move downstream--115 cubic feet per second through a culvert and 200 cubic feet per second over the highway. Simulated water-surface elevation at this crossing was 0.8 foot higher than the elevation of the highway. The remaining 385 cubic feet per second flowed southwestward in a trench along the north side of the highway. Flow also was simulated with the culvert removed. The exact location of flood boundaries on Birch Creek could not be determined because of the highly braided channel and the many anthropogenic features (such as the trench, highway, and diversion channels) in the study area that affect flood hydraulics and flow. Because flood boundaries could not be located exactly, only a generalized flood-prone map was developed.

  3. 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.

  4. Beyond the veil: Inner horizon instability and holography

    NASA Astrophysics Data System (ADS)

    Balasubramanian, Vijay; Levi, Thomas S.

    2004-11-01

    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.

  5. Modeling of the development of humus horizons in soils of Crimea

    NASA Astrophysics Data System (ADS)

    Ergina, E. I.

    2017-01-01

    Current approaches to the simulation of pedogenesis processes in time are considered. Models for the formation of humus horizon on parent rocks of different genesis in Crimea are presented. Formation rates of humus horizons have been determined, which allows developing the remediation strategies for mining dumps of mineral deposits in Crimea.

  6. Oil sheen weathering post Deepwater Horizon

    NASA Astrophysics Data System (ADS)

    Kellermann, M. Y.; Redmond, M. C.; Reddy, C. M.; Aeppli, C.; Nelson, R. K.; Valentine, D. L.

    2013-12-01

    A recently published study identified the source of the reoccurred oil sheens close to the Deepwater Horizon (DWH) disaster site as a finite contamination most likely derived from tanks and pits on the DWH wreckage itself. Here we use geochemical fingerprinting and microbial community analysis to better understand the fate and weathering processes affecting these surface oils. Both, alkanes and polycyclic aromatic hydrocarbons (PAHs) are shown to reflect a linear decrease of hydrocarbon compounds with increasing distance to the DWH wreckage site (equivalent to exposure time on the sea surface). These results indicate that in the early stage of weathering the combined effects of dissolution and evaporation dominate the degradation of these surface oils. Sheen microbial communities were dominated by Cyanobacteria, Planctomycetes, Verrucomicrobia, Flavobacteria, Alphaproteobacteria, and Deltaproteobacteria, with low relative abundances of Gammaproteobacteria likely to be hydrocarbon degraders (no more than 15% of sequences in each sample). However, some of these Gammaproteobacteria were closely related to putative hydrocarbon degraders observed in abundance in deep water plumes during the primary Deepwater Horizon spill, suggesting that very low levels of biodegradation may be also occurring. This in situ weathering experiment provides new insights in hydrocarbon weathering dynamics and shows how chemical and biological changes can potentially be masked by large evaporative losses of compounds smaller than C18 n-alkanes.

  7. [Effects of Slope Position and Soil Horizon on Soil Microbial Biomass and Abundance in Karst Primary Forest of Southwest China].

    PubMed

    Feng, Shu-zhen; Su, Yi-rong; Zhang, Wei; Chen, Xiang-bi; He, Xun-yang

    2015-10-01

    To explore the effects of slope position and soil horizon on soil microbial biomass and abundance, chloroform fumigation extraction methods and real-time fluorescence-based quantitative PCR (Real-time PCR) were adopted to quantify the changes of soil microbial biomass C, N and abundance of bacteria and fungi, respectively. Soil samples were harvested from three horizons along profile, i. e., leaching horizon (A, 0-10 cm), transitional horizon (AB, 30-50 cm) and alluvial horizon (B, 70-100 cm), which were collected from the upper, middle and lower slope positions of a karst primary forest ecosystem. The results showed that slope position, soil horizon and their interaction significantly influenced the soil microbial biomass and abundance (P < 0.05). Different from A horizon, where SMBC was greater in lower than in upper slope position (P < 0.05), SMBC in AB and B horizons were highest in middle slope position. Similarly, SMBN was greater in lower than in upper slope position for A, AB and B horizons. Besides soil bacterial abundance in B horizon and fungal abundance in AB layer, the middle slope position had the highest value for all the three soil horizons (P < 0.05). Stepwise regression analysis showed that soil organic carbon, available nitrogen and pH were the key factors responsible for SMBC and SMBN variation, respectively, while the important factors responsible for the variation of bacteria abundance were available nitrogen and available phosphorus, and that for fungi abundance variation were available potassium.

  8. Over 100 years of environmental change recorded by foraminifers and sediments in a large Gulf of Mexico estuary, Mobile Bay, AL, USA

    USGS Publications Warehouse

    Osterman, Lisa E.; Smith, Christopher G.

    2012-01-01

    The marine microfauna of Mobile Bay has been profoundly influenced by the development and expansion of the primary shipping channel over the last ˜100 years. Foraminifers and sediments from seven box cores with excess lead-210 chronology document that channel dredging and spoil disposal have altered circulation, reduced estuarine mixing, changed sedimentation patterns, and caused a faunal turnover within the bay. Beginning in the late 1800s, changes in estuarine mixing allowed for greater low-pH freshwater influence in the bay, and ultimately began environmental changes that resulted in the loss of calcareous foraminifers. By the early 1900s, box cores throughout Mobile Bay record a ˜ 100-year trend of increasing calcareous test dissolution that continues to the present. Since the completion of the current shipping channel in the 1950s, restricted tidal flushing and increased terrestrial organic matter, documented by carbon-to-nitrogen ratios, stimulated an increase in agglutinated foraminiferal densities. However, in deeper areas of the bay, hypoxic water has negatively impacted the marine microfauna. Comparisons of the present-day foraminiferal assemblage with foraminifers collected in the early 1970s indicate that the continued biologic loss of calcareous foraminifers in the bay has allowed the introduction of a new agglutinated foraminiferal species into the bay.

  9. Variable horizon in a peridynamic medium

    DOE PAGES

    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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. Noncommutativity in near horizon symmetries in gravity

    NASA Astrophysics Data System (ADS)

    Majhi, Bibhas Ranjan

    2017-02-01

    We have a new observation that near horizon symmetry generators, corresponding to diffeomorphisms which leave the horizon structure invariant, satisfy noncommutative Heisenberg algebra. The results are valid for any null surfaces (which have Rindler structure in the near null surface limit) and in any spacetime dimensions. Using the Sugawara construction technique the central charge is identified. It is shown that the horizon entropy is consistent with the standard form of the Cardy formula. Therefore we feel that the noncommutative algebra might lead to quantum mechanics of horizon and also can probe into the microscopic description of entropy.

  16. Horizons of semiclassical black holes are cold

    NASA Astrophysics Data System (ADS)

    Brustein, Ram; Medved, A. J. M.

    2014-06-01

    We calculate, using our recently proposed semiclassical framework, the quantum state of the Hawking pairs that are produced during the evaporation of a black hole (BH). Our framework adheres to the standard rules of quantum mechanics and incorporates the quantum fluctuations of the collapsing shell spacetime in Hawking's original calculation, while accounting for back-reaction effects. We argue that the negative-energy Hawking modes need to be regularly integrated out; and so these are effectively subsumed by the BH and, as a result, the number of coherent negative-energy modes N coh at any given time is parametrically smaller than the total number of the Hawking particles N total emitted during the lifetime of the BH. We find that N coh is determined by the width of the BH wavefunction and scales as the square root of the BH entropy. We also find that the coherent negative-energy modes are strongly entangled with their positive-energy partners. Previously, we have found that N coh is also the number of coherent outgoing particles and that information can be continually transferred to the outgoing radiation at a rate set by N coh . Our current results show that, while the BH is semiclassical, information can be released without jeopardizing the nearly maximal inside-out entanglement and imply that the state of matter near the horizon is approximately the vacuum. The BH firewall proposal, on the other hand, is that the state of matter near the horizon deviates substantially from the vacuum, starting at the Page time. We find that, under the usual assumptions for justifying the formation of a firewall, one does indeed form at the Page time. However, the possible loophole lies in the implicit assumption that the number of strongly entangled pairs can be of the same order of N total .

  17. A geochemical record of environmental changes in sediments from Sishili Bay, northern Yellow Sea, China: anthropogenic influence on organic matter sources and composition over the last 100 years.

    PubMed

    Wang, Yujue; Liu, Dongyan; Richard, Pierre; Li, Xin

    2013-12-15

    Total organic carbon (TOC), total nitrogen (TN), δ(13)C and δ(15)N were measured in sediment cores at three sites in Sishili Bay, China, to track the impacts of anthropogenic activities on the coastal environment over the last 100 years. The increased TOC and TN in the upper section of sediment cores indicated a eutrophic process since 1975. In comparison, the TOC and TN in the sediment core near to a scallop aquaculture area displayed a much slower increase, indicating the contribution of scallop aquaculture in mitigating eutrophication. Combined information from δ(13)C, δ(15)N and TOC:TN indicated an increased terrestrial signal, although organic matter sources in Sishili Bay featured a mixture of terrestrial and marine sources, with phytoplankton being dominant. Increased fertilizer use since 1970s contributed to the eutrophic process in Sishili Bay since 1975, and increased sewage discharge from 1990s has added to this process.

  18. [100 years after Kienböck's description: review of the etiology of Kienböck's disease from a historical perspective].

    PubMed

    Stahl, S; Lotter, O; Santos Stahl, A; Meisner, C; Luz, O; Pfau, M; Schaller, H-E

    2012-01-01

    Kienböck's disease (KD) leads to collapse of the lunate bone with severe consequences for the wrist function which for some patients may result in occupational invalidity. The many synonyms of KD (aseptic necrosis or avascular necrosis) insinuate that the true etiopathology remains poorly understood. This reviews aims at exploring the level of evidence which brought forward the different hypotheses on the origin of KD. The widespread theories about the origin were formed about 100 years ago but a specific therapy is still not within reach. Although the cause of the disease remains essentially unknown it is officially recognized as an occupational disease in Germany. Empirical attempts to explain the etiopathology are based on compression of the lunate, impaired vascularity through vibration exposition, fracture and dislocation of the lunate from the radiolunate fossa. The level of evidence urges a cautious interpretation of currently discussed hypotheses on the etiology of KD.

  19. CoSMoS Southern California v3.0 Phase 1 (100-year storm) flood hazard projections: Los Angeles, San Diego and Orange counties

    USGS Publications Warehouse

    Barnard, Patrick; Erikson, Li; Foxgrover, Amy; O'Neill, Andrea; Herdman, Liv

    2015-01-01

    The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of kilometers) of storm-induced coastal flooding and erosion for both current and future sea-level rise (SLR) scenarios. CoSMoS v3.0 for Southern California shows projections for future climate scenarios (sea-level rise and storms) to provide emergency responders and coastal planners with critical storm-hazards information that can be used to increase public safety, mitigate physical damages, and more effectively manage and allocate resources within complex coastal settings. Phase I data for Southern California include flood-hazard information for the coast from the Mexican Border to Pt. Conception for a 100-year storm scenario. Data are complete for the information presented but are considered preliminary; changes may be reflected in the full data release (Phase II) in summer 2016.

  20. History of views on the relative positions of Antarctica and South America: A 100-year tango between Patagonia and the Antarctic Peninsula

    USGS Publications Warehouse

    Miller, H.

    2007-01-01

    Discussion of continental drift around Antarctica began nearly 100 years ago. While the Gondwana connections of Antarctica to Africa and Australia have been well defined for decades, the relative pre-drift positions of the Antarctic Peninsula and Patagonia continue to be subjects of controversy. Certainly older figures, which showed a paleo-position of the Peninsula crossing over continental crust of the Falkland Plateau or even South Africa or Patagonia, are out of consideration now. But contradictory opinions remain over the relative paleo-position of the Peninsula as a more or less straight prolongation of the Patagonian Andes, versus a position parallel to Patagonia along the Pacific coast. Geological reasons are found for both opinions, but geophysical observations on the adjacent ocean floors, particularly the evolution of the Weddell Sea crust, speak for the last-mentioned reconstruction.

  1. [Medical research travel 100 years ago: the 14th German Medical Study Trip to North America and Canada in the year 1912].

    PubMed

    Neid, T; Helm, J

    2012-12-01

    Already before the First World War the North American medicine had developed within less years so far that it had an excellent reputation and that famous scientists and medicines from Europe came in the country for extensive study trips and congressional visits. Exactly 100 years ago the delegation biggest till then of German doctors visited in the course of the 14th German Medical Study Trip the United States of America. The very amicable relation between the doctors of both nations made easier the scientific exchange during this study trip and allowed a deep insight into the medicine of the USA to the participants. Even though the German doctors were very impressed with the developement in the USA and reported partly in their native country in detail about that, it didn't succeed in keeping pace with the rapid developement of the USA into the leading research nation in the following decades.

  2. Changes in C37 alkenones flux on the eastern continental shelf of the Bering Sea: the record of Emiliania huxleyi bloom over the past 100 years

    NASA Astrophysics Data System (ADS)

    Harada, N.; Sato, M.; Okazaki, Y.; Oguri, K.; Tadai, O.; Saito, S.; Konno, S.; Jordan, R. W.; Katsuki, K.; Shin, K.; Narita, H.

    2008-12-01

    Flourishes of coccolithophores can be detected by ocean color imagery with data from the satellite-borne Sea-viewing Wide Field-of-view sensor SeaWiFs that was launched in 1997. Thus, temporally and spatially large-scale blooms of Emiliania huxleyi (E. huxleyi) have been distinguished annually in the eastern continental shelf of the Bering Sea since 1997. In 1997, a combination of atmospheric mechanisms produced summer weather anomalies such as calm winds, clear skies, and warm air temperature over the Bering Sea and the weather anomalies caused depletion of the subpycnocline nutrient reservoir (Napp and Hunt, 2001). After depletion of nitrate and silicate, a sustained (more than 4-month-long) bloom of E. huxleyi was observed (Stockwell et al., 2001). Because of the speed and magnitude with which parts of the Bering Sea ecosystem responded to changes in atmospheric factors (Napp and Hunt, 2001) and because a bloom of the coccolithophorid, Coccolithus pelagicus has also been detected in the northeastern Atlantic Ocean off Iceland every year since 1997 (Ostermann, 2001), the appearance of an E. huxleyi bloom in the Bering Sea could be related to atmospherically forced decadal oscillations or global factors. We have investigated spatial expansion and temporal development of E. huxleyi bloom on the continental shelf in the Bering Sea by using a biomarker of E. huxleyi, C37 alkenones flux recorded in the sediments during the past 100 years. As a result, the E. huxleyi bloom had been prominent since 1970"fs at latest during the last 100 years. In this presentation, we will discuss the relationship between E. huxleyi bloom and activity of Aleutian low, and also changes in diatom assemblages. References Napp and Hunt, 2001, Fish Oceanogr., 10, 61-68. Ostermann, 2001, WHOI annual report, pp.17-18. Stockwell et al., 2001, Fish Oceanogr., 10, 99-116.

  3. Digital depth horizon compilations of the Alaskan North Slope and adjacent Arctic regions

    USGS Publications Warehouse

    Saltus, Richard W.; Bird, Kenneth J.

    2003-01-01

    Data have been digitized and combined to create four detailed depth horizon grids spanning the Alaskan North Slope and adjacent offshore areas. These map horizon compilations were created to aid in petroleum system modeling and related studies. Topography/bathymetry is extracted from a recent Arctic compilation of global onshore DEM and satellite altimetry and ship soundings offshore. The Lower Cretaceous Unconformity (LCU), the top of the Triassic Shublik Formation, and the pre-Carboniferous acoustic basement horizon grids are created from numerous seismic studies, drill hole information, and interpolation. These horizons were selected because they mark critical times in the geologic evolution of the region as it relates to petroleum. The various horizons clearly show the major tectonic elements of this region including the Brooks Range, Colville Trough, Barrow Arch, Hanna Trough, Chukchi Platform, Nuwuk Basin, Kaktovik Basin, and Canada Basin. The gridded data are available in a variety of data formats for use in regional studies.

  4. 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…

  5. 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…

  6. 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…

  7. 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.

  8. Stabilizing State-Feedback Design via the Moving Horizon Method.

    DTIC Science & Technology

    1982-01-01

    aide if necessary and identify by block number) Stabilizing control design; linear time varying systems; fixed depth horizon; index optimization methods...dual system. 20. ABSTRACT (Continue an reverse side If necessary and Identify by block number) Li _ A stabilizing control design for general linear...Apprvyed for pb~ ~~* 14 ~dl Stri but ion uni imit Oe, ABSTRACT A stabilizing control design for general linear time vary- invariant systems through

  9. Planning horizon affects prophylactic decision-making and epidemic dynamics

    PubMed Central

    Ridenhour, Benjamin J.; Krone, Stephen M.

    2016-01-01

    The spread of infectious diseases can be impacted by human behavior, and behavioral decisions often depend implicitly on a planning horizon—the time in the future over which options are weighed. We investigate the effects of planning horizons on epidemic dynamics. We developed an epidemiological agent-based model (along with an ODE analog) to explore the decision-making of self-interested individuals on adopting prophylactic behavior. The decision-making process incorporates prophylaxis efficacy and disease prevalence with the individuals’ payoffs and planning horizon. Our results show that for short and long planning horizons individuals do not consider engaging in prophylactic behavior. In contrast, individuals adopt prophylactic behavior when considering intermediate planning horizons. Such adoption, however, is not always monotonically associated with the prevalence of the disease, depending on the perceived protection efficacy and the disease parameters. Adoption of prophylactic behavior reduces the epidemic peak size while prolonging the epidemic and potentially generates secondary waves of infection. These effects can be made stronger by increasing the behavioral decision frequency or distorting an individual’s perceived risk of infection. PMID:27843714

  10. 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.

  11. A 100-Year Retrospective Landscape-Level Carbon Budget for the Sooke Lake Watershed, British Columbia: Constraining Estimates of Terrestrial to Aquatic DOC Transfers.

    NASA Astrophysics Data System (ADS)

    Trofymow, J. A.; Smiley, B. P. K.

    2014-12-01

    To address how natural disturbance, forest harvest, and deforestation from reservoir creation affect landscape-level carbon (C) budgets, a retrospective C budget for the 8500 ha Sooke watershed from 1911 - 2012 was developed using historic spatial inventory and disturbance data. Data was input to a spatially-explicit version of the Carbon Budget Model-Canadian Forest Sector (CBM-CFS3), an inventory-based C budget model used to simulate forest C dynamics at multiple scales. In 1911 the watershed was dominated by mature/old Douglas-fir forests with aboveground biomass C (ABC) of 262 Mg C/ha and net ecosystem production (NEP) of 0.63 Mg C/ha/yr. Land was cleared around Sooke Lake, a dam built and lake expanded from 370 to 450 ha in 1915, 610 ha in 1970, 670 ha in 1980 and 810 ha in 2002. Along with deforestation, fires and localized harvest occurred from 1920 - 1940, reducing ABC to 189 Mg C/ha, with NEP varying from -1.63 to 0.13 Mg C/ha/yr. Distributed harvest occurred 1954 - 1998, with a minimum ABC of 148 Mg C/ha in 1991. By 2012 ABC (177 Mg C/ha) and NEP (2.29 Mg C/ha/yr) had increased. Over 100 years, 2430 ha forest was cut and replanted and 640 ha deforested. CBM-CFS3 includes transfers of dissolved organic C (DOC) to aquatic systems, however data has not been available to parameterize DOC flux. DOC fluxes are modelled as a fraction of decay loss from humified soil C with a default of 100% of losses to CO2 and 0% to DOC. Stream flow and [DOC] data from 1996 - 2012 for 3 watershed catchments, Rithet, Judge and Council were used to estimate annual DOC fluxes. Rithet, Judge and Council differed both in area % disturbed (logging or fire) over 100 years (39%, 93%, 91%) and in area % mature/old forest (>80yrs in 2012) (67%, 56%, 21%). DOC flux for Rithet and Judge ranged from 0.037 - 0.057 Mg C/ha/yr, Council averaged 0.017 Mg C/ha/yr. Low DOC fluxes were likely due to influences of a small lake in the catchment. Constraining CBM-CFS3 to observed DOC fluxes, required

  12. 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...

  13. Intraspecific variation in fine root respiration and morphology in response to in situ soil nitrogen fertility in a 100-year-old Chamaecyparis obtusa forest.

    PubMed

    Makita, Naoki; Hirano, Yasuhiro; Sugimoto, Takanobu; Tanikawa, Toko; Ishii, Hiroaki

    2015-12-01

    Soil N fertility has an effect on belowground C allocation, but the physiological and morphological responses of individual fine root segments to variations in N availability under field conditions are still unclear. In this study, the direction and magnitude of the physiological and morphological function of fine roots in response to variable in situ soil N fertility in a forest site were determined. We measured the specific root respiration (Rr) rate, N concentration and morphology of fine root segments with 1-3 branching orders in a 100-year-old coniferous forest of Chamaecyparis obtusa. Higher soil N fertility induced higher Rr rates, root N concentration, and specific root length (SRL), and lower root tissue density (RTD). In all fertility levels, the Rr rates were significantly correlated positively with root N and SRL and negatively with RTD. The regression slopes of respiration with root N and RTD were significantly higher along the soil N fertility gradient. Although no differences in the slopes of Rr and SRL relationship were found across the levels, there were significant shifts in the intercept along the common slope. These results suggest that a contrasting pattern in intraspecific relationships between specific Rr and N, RTD, and SRL exists among soils with different N fertility. Consequently, substantial increases in soil N fertility would exert positive effects on organ-scale root performance by covarying the Rr, root N, and morphology for their potential nutrient and water uptake.

  14. Organochlorine pesticides (OCPs) in wetland soils under different land uses along a 100-year chronosequence of reclamation in a Chinese estuary

    NASA Astrophysics Data System (ADS)

    Bai, Junhong; Lu, Qiongqiong; Zhao, Qingqing; Wang, Junjing; Gao, Zhaoqin; Zhang, Guangliang

    2015-12-01

    Soil profiles were collected at a depth of 30 cm in ditch wetlands (DWs), riverine wetlands (RiWs) and reclaimed wetlands (ReWs) along a 100-year chronosequence of reclamation in the Pearl River Delta. In total, 16 OCPs were measured to investigate the effects of wetland reclamation and reclamation history on OCP levels. Our results showed that average ∑DDTs, HCB, MXC, and ∑OCPs were higher in surface soils of DWs compared to RiWs and ReWs. Both D30 and D20 soils contained the highest ∑OCP levels, followed by D40 and D100 soils; lower ∑OCP levels occurred in D10 soils. Higher ∑OCP levels were observed in the younger RiWs than in the older ones, and surface soils exhibited higher ∑OCP concentrations in the older ReWs compared with younger ReWs. The predominant percentages of γ-HCH in ∑HCHs (>42%) and aldrin in ∑DRINs (>46%) in most samples reflected the recent use of lindane and aldrin. The presence of dominant DDT isomers (p,p’-DDE and p,p’-DDD) indicated the historical input of DDT and significant aerobic degradation of the compound. Generally, DW soils had a higher ecotoxicological risk of OCPs than RiW and ReW soils, and the top 30 cm soils had higher ecotoxicological risks of HCHs than of DDTs.

  15. Evolution of US maize (Zea mays L.) root architectural and anatomical phenes over the past 100 years corresponds to increased tolerance of nitrogen stress

    PubMed Central

    York, Larry M.; Galindo-Castañeda, Tania; Schussler, Jeffrey R.; Lynch, Jonathan P.

    2015-01-01

    Increasing the nitrogen use efficiency of maize is an important goal for food security and agricultural sustainability. In the past 100 years, maize breeding has focused on yield and above-ground phenes. Over this period, maize cultivation has changed from low fertilizer inputs and low population densities to intensive fertilization and dense populations. The authors hypothesized that through indirect selection the maize root system has evolved phenotypes suited to more intense competition for nitrogen. Sixteen maize varieties representing commercially successful lines over the past century were planted at two nitrogen levels and three planting densities. Root systems of the most recent material were 7 º more shallow, had one less nodal root per whorl, had double the distance from nodal root emergence to lateral branching, and had 14% more metaxylem vessels, but total mextaxylem vessel area remained unchanged because individual metaxylem vessels had 12% less area. Plasticity was also observed in cortical phenes such as aerenchyma, which increased at greater population densities. Simulation modelling with SimRoot demonstrated that even these relatively small changes in root architecture and anatomy could increase maize shoot growth by 16% in a high density and high nitrogen environment. The authors concluded that evolution of maize root phenotypes over the past century is consistent with increasing nitrogen use efficiency. Introgression of more contrasting root phene states into the germplasm of elite maize and determination of the functional utility of these phene states in multiple agronomic conditions could contribute to future yield gains. PMID:25795737

  16. Quantification of uncertainties in the 100-year flow at an ungaged site near a gaged station and its application in Georgia

    NASA Astrophysics Data System (ADS)

    Cho, Huidae; Bones, Emma

    2016-08-01

    The Federal Emergency Management Agency has introduced the concept of the "1-percent plus" flow to incorporate various uncertainties in estimation of the 100-year or 1-percent flow. However, to the best of the authors' knowledge, no clear directions for calculating the 1-percent plus flow have been defined in the literature. Although information about standard errors of estimation and prediction is provided along with the regression equations that are often used to estimate the 1-percent flow at ungaged sites, uncertainty estimation becomes more complicated when there is a nearby gaged station because regression flows and the peak flow estimate from a gage analysis should be weighted to compute the weighted estimate of the 1-percent flow. In this study, an equation for calculating the 1-percent plus flow at an ungaged site near a gaged station is analytically derived. Also, a detailed process is introduced for calculating the 1-percent plus flow for an ungaged site near a gaged station in Georgia as an example and a case study is performed. This study provides engineers and practitioners with a method that helps them better assess flood risks and develop mitigation plans accordingly.

  17. Organochlorine pesticides (OCPs) in wetland soils under different land uses along a 100-year chronosequence of reclamation in a Chinese estuary

    PubMed Central

    Bai, Junhong; Lu, Qiongqiong; Zhao, Qingqing; Wang, Junjing; Gao, Zhaoqin; Zhang, Guangliang

    2015-01-01

    Soil profiles were collected at a depth of 30 cm in ditch wetlands (DWs), riverine wetlands (RiWs) and reclaimed wetlands (ReWs) along a 100-year chronosequence of reclamation in the Pearl River Delta. In total, 16 OCPs were measured to investigate the effects of wetland reclamation and reclamation history on OCP levels. Our results showed that average ∑DDTs, HCB, MXC, and ∑OCPs were higher in surface soils of DWs compared to RiWs and ReWs. Both D30 and D20 soils contained the highest ∑OCP levels, followed by D40 and D100 soils; lower ∑OCP levels occurred in D10 soils. Higher ∑OCP levels were observed in the younger RiWs than in the older ones, and surface soils exhibited higher ∑OCP concentrations in the older ReWs compared with younger ReWs. The predominant percentages of γ-HCH in ∑HCHs (>42%) and aldrin in ∑DRINs (>46%) in most samples reflected the recent use of lindane and aldrin. The presence of dominant DDT isomers (p,p’-DDE and p,p’-DDD) indicated the historical input of DDT and significant aerobic degradation of the compound. Generally, DW soils had a higher ecotoxicological risk of OCPs than RiW and ReW soils, and the top 30 cm soils had higher ecotoxicological risks of HCHs than of DDTs. PMID:26633149

  18. Seasonal solar wind speeds for the last 100 years: Unique coronal hole structures during the peak and demise of the Grand Modern Maximum

    NASA Astrophysics Data System (ADS)

    Mursula, K.; Holappa, L.; Lukianova, R.

    2017-01-01

    Solar coronal holes are sources of high-speed solar wind streams, which cause persistent geomagnetic activity especially at high latitudes. Here we estimate seasonal solar wind speeds at 1 AU for the last 100 years using high-latitude geomagnetic measurements and show that they give information on the long-term evolution of important structures of the solar large-scale magnetic field, such as persistent coronal holes. We find that the centennial evolution of solar wind speed at 1 AU is different for equinoxes and solstices, reflecting differences in the evolution of polar coronal hole extensions and isolated low-latitude coronal holes. Equinoctial solar wind speeds had their centennial maximum in 1952, during the declining phase of solar cycle 18, verifying that polar coronal holes had exceptionally persistent extensions just before the peak of the Grand Modern Maximum of solar activity. On the other hand, solstice speeds had their centennial maximum during the declining phase of solar cycle 23 due to large low-latitude coronal holes. A similar configuration of seasonal speeds as in cycle 23 was not found earlier, not even during the less active cycles of early 20th century. Therefore, the exceptional occurrence of persistent, isolated low-latitude coronal holes in cycle 23 is not related to the absolute level of sunspot activity but, most likely, to the demise of the Grand Modern Maximum.

  19. 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.

  20. 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

  1. 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.

  2. Friedmann equations and thermodynamics of apparent horizons.

    PubMed

    Gong, Yungui; Wang, Anzhong

    2007-11-23

    With the help of a masslike function which has a dimension of energy and is equal to the Misner-Sharp mass at the apparent horizon, we show that the first law of thermodynamics of the apparent horizon dE=T(A)dS(A) can be derived from the Friedmann equation in various theories of gravity, including the Einstein, Lovelock, nonlinear, and scalar-tensor theories. This result strongly suggests that the relationship between the first law of thermodynamics of the apparent horizon and the Friedmann equation is not just a simple coincidence, but rather a more profound physical connection.

  3. Considerations on the thermal equilibrium between matter and the cosmic horizon

    NASA Astrophysics Data System (ADS)

    Mimoso, José Pedro; Pavón, Diego

    2016-11-01

    A common feature in the thermodynamic analysis of homogeneous and isotropic world models is the assumption that the temperature of the fluids inside the cosmic horizon (including dark energy) coincides with the temperature of the latter, whether it be either the event or the apparent horizon. We examine up to what extent this assumption may be justified, given that these temperatures evolve under different time-temperature laws. We argue that while radiation cannot reach thermal equilibrium with the horizon, nonrelativistic matter may, and dark energy might though only approximately.

  4. Innate threat-sensitive foraging: black-tailed deer remain more fearful of wolf than of the less dangerous black bear even after 100 years of wolf absence.

    PubMed

    Chamaillé-Jammes, Simon; Malcuit, Hélène; Le Saout, Soizic; Martin, Jean-Louis

    2014-04-01

    Anti-predator behaviors often entail foraging costs, and thus prey response to predator cues should be adjusted to the level of risk (threat-sensitive foraging). Simultaneously dangerous predators (with high hunting success) should engender the evolution of innate predator recognition and appropriate anti-predator behaviors that are effective even upon the first encounter with the predator. The above leads to the prediction that prey might respond more strongly to cues of dangerous predators that are absent, than to cues of less dangerous predators that are actually present. In an applied context this would predict an immediate and stronger response of ungulates to the return of top predators such as wolves (Canis lupus) in many parts of Europe and North America than to current, less threatening, mesopredators. We investigated the existence of innate threat-sensitive foraging in black-tailed deer. We took advantage of a quasi-experimental situation where deer had not experienced wolf predation for ca. 100 years, and were only potentially exposed to black bears (Ursus americanus). We tested the response of deer to the urine of wolf (dangerous) and black bear (less dangerous). Our results support the hypothesis of innate threat-sensitive foraging with clear increased passive avoidance and olfactory investigation of cues from wolf, and surprisingly none to black bear. Prey which have previously evolved under high risk of predation by wolves may react strongly to the return of wolf cues in their environments thanks to innate responses retained during the period of predator absence, and this could be the source of far stronger non-consumptive effects of the predator guild than currently observed.

  5. Polychlorinated biphenyls (PCBs) in sediments/soils of different wetlands along 100-year coastal reclamation chronosequence in the Pearl River Estuary, China.

    PubMed

    Zhao, Qingqing; Bai, Junhong; Lu, Qiongqiong; Gao, Zhaoqin; Jia, Jia; Cui, Baoshan; Liu, Xinhui

    2016-06-01

    PCBs (polychlorinated biphenyls) were determined in sediment/soil profiles to a depth of 30 cm from three different wetlands (i.e., ditch wetlands, riparian wetlands and reclaimed wetlands) of the Pearl River Estuary to elucidate their levels, distribution and toxic risks along a 100-year chronosequence of reclamation. All detected PCB congeners and the total 15 PCBs (∑15 PCBs) decreased with depth along sediment/soil profiles in these three wetlands. The ∑15 PCBs concentrations ranged from 17.68 to 169.26 ng/g in surface sediments/soils. Generally, old wetlands tended to have higher PCB concentrations than younger ones. The dominant PCB congeners at all sampling sites were light PCB homologues (i.e., tetra-CBs and tri-CBs). According to the sediment quality guideline, the average PCB concentrations exceeded the threshold effects level (TEL, 21.6 ng/g) at most of the sampling sites, exhibiting possible adverse biological effects, which were dominantly caused by light PCB congeners. The total toxic equivalent (TEQ) concentrations of 10 dioxin-like PCBs (DL-PCBs) detected at all sampling sites ranged from 0.04 to 852.7 (10(-3) ng/g), mainly affected by PCB126. Only DL-PCB concentrations in ditch and riparian wetland sediments with 40-year reclamation histories (i.e., D40 and Ri40) exhibited moderate adverse biological effects according to SQGQ values. Principal component analysis indicated that PCBs in three wetland sediments/soils mainly originated from Aroclor 1016, 1242, and 1248. Correlation analysis showed that sediment/soil organic carbon content had a significant correlation with the concentrations of several PCB congeners (P < 0.05), whereas no significant correlations were observed between any PCBs congeners and grain size or aggregate content (P > 0.05).

  6. Changes in stable isotopes, lignin-derived phenols, and fossil pigments in sediments of Lake Biwa, Japan: implications for anthropogenic effects over the last 100 years.

    PubMed

    Hyodo, Fujio; Tsugeki, Narumi; Azuma, Jun-Ichi; Urabe, Jotaro; Nakanishi, Masami; Wada, Eitaro

    2008-09-15

    We measured stable nitrogen (N) and carbon (C) isotope ratios, lignin-derived phenols, and fossil pigments in sediments of known ages to elucidate the historical changes in the ecosystem status of Lake Biwa, Japan, over the last 100 years. Stable N isotope ratios and algal pigments in the sediments increased rapidly from the early 1960s to the 1980s, and then remained relatively constant, indicating that eutrophication occurred in the early 1960s but ceased in the 1980s. Stable C isotope ratios of the sediment increased from the 1960s, but decreased after the 1980s to the present. This decrease in stable C isotope ratios after the 1980s could not be explained by annual changes in either terrestrial input or algal production. However, when the C isotope ratios were corrected for the Suess effect, the shift to more negative isotopic value in atmospheric CO(2) by fossil fuel burning, the isotopic value showed a trend, which is consistent with the other biomarkers and the monitoring data. The trend was also mirrored by the relative abundance of lignin-derived phenols, a unique organic tracer of material that originated from terrestrial plants, which decreased in the early 1960s and recovered to some degree in the 1980s. We detected no notable difference in the composition of lignin phenols, suggesting that the terrestrial plant composition did not change markedly. However, we found that lignin accumulation rate increased around the 1980s. These results suggest that although eutrophication has stabilized since the 1980s, allochthonous organic matter input has changed in Lake Biwa over the past 25 years.

  7. Climatic selection on genes and traits after a 100 year-old invasion: a critical look at the temperate-tropical clines in Drosophila melanogaster from eastern Australia.

    PubMed

    Hoffmann, Ary A; Weeks, Andrew R

    2007-02-01

    Drosophila melanogaster invaded Australia around 100 years ago, most likely through a northern invasion. The wide range of climatic conditions in eastern Australia across which D. melanogaster is now found provides an opportunity for researchers to identify traits and genes that are associated with climatic adaptation. Allozyme studies indicate clinal patterns for at least four loci including a strong linear cline in Adh and a non-linear cline in alpha-Gpdh. Inversion clines were initially established from cytological studies but have now been validated with larger sample sizes using molecular markers for breakpoints. Recent collections indicate that some genetic markers (Adh and In(3R)Payne) have changed over the last 20 years reflecting continuing evolution. Heritable clines have been established for quantitative traits including wing length/area, thorax length and cold and heat resistance. A cline in egg size independent of body size and a weak cline in competitive ability have also been established. Postulated clinal patterns for resistance to desiccation and starvation have not been supported by extensive sampling. Experiments under laboratory and semi-natural conditions have suggested selective factors generating clinal patterns, particularly for reproductive patterns over winter. Attempts are being made to link clinal variation in traits to specific genes using QTL analysis and the candidate locus approach, and to identify the genetic architecture of trait variation along the cline. This is proving difficult because of inversion polymorphisms that generate disequilibrium among genes. Substantial gaps still remain in linking clines to field selection and understanding the genetic and physiological basis of the adaptive shifts. However D. melanogaster populations in eastern Australia remain an excellent resource for understanding past and future evolutionary responses to climate change.

  8. Central control of information transmission through the intraspinal arborizations of sensory fibers examined 100 years after Ramón y Cajal.

    PubMed

    Rudomin, Pablo

    2002-01-01

    About 100 years ago, Santiago Ramón y Cajal reported that sensory fibers entering the spinal cord have ascending and descending branches, and that each of them sends collaterals to the gray matter where they have profuse ramifications. To him this was a fundamental discovery and proposed that the intraspinal branches of the sensory fibers were "centripetal conductors by which sensory excitation is propagated to the various neurons in the gray matter". In addition, he assumed that "conduction of excitation within the intraspinal arborizations of the afferent fibers would be proportional to the diameters of the conductors", and that excitation would preferentially flow through the coarsest branches. The invariability of some elementary reflexes such as the knee jerk would be the result of a long history of plastic adaptations and natural selection of the safest neuronal organizations. There is now evidence suggesting that in the adult cat, the intraspinal branches of sensory fibers are not hard wired routes that diverge excitation to spinal neurons in an invariable manner, but rather dynamic pathways where excitation flow can be centrally addressed to reach specific neuronal targets. This central control of information flow is achieved by means of specific sets of GABAergic interneurons that produce primary afferent depolarization (PAD) via axo-axonic synapses and reduce transmitter release (presynaptic inhibition). The PAD produced by single, or by small groups of GABAergic interneurons in group I muscle afferents, can remain confined to some sets of intraspinal arborizations of the afferent fibers and not spread to nearby collaterals. In muscle spindle afferents this local character of PAD allows cutaneous and descending inputs to differentially inhibit the PAD in segmental and ascending collaterals of individual fibers, which may be an effective way to decouple the information flow arising from common sensory inputs. This feature appears to play an important role

  9. Fractionation, transfer, and ecological risks of heavy metals in riparian and ditch wetlands across a 100-year chronosequence of reclamation in an estuary of China.

    PubMed

    Xiao, Rong; Bai, Junhong; Lu, Qiongqiong; Zhao, Qingqing; Gao, Zhaoqin; Wen, Xiaojun; Liu, Xinhui

    2015-06-01

    The effect of reclamation on heavy metal concentrations and the ecological risks in ditch wetlands (DWs) and riparian wetlands (RWs) across a 100-year chronosequence in the Pearl River Estuary of China was investigated. Concentrations of 4 heavy metals (Cd, Cu, Pb, and Zn) in soil and plant samples, and sequential extracts of soil samples were determined, using inductively coupled plasma atomic absorption spectrometry. Results showed that heavy metal concentrations were higher in older DW soils than in the younger ones, and that the younger RW soils contained higher heavy metal concentrations compared to the older ones. Although the increasing tendency of heavy metal concentrations in soil was obvious after wetland reclamation, the metals Cu, Pb, and Zn exhibited low or no risks to the environment based on the risk assessment code (RAC). Cd, on the other hand, posed a medium or high risk. Cd, Pb, and Zn were mainly bound to Fe-Mn oxide, whereas most of Cu remained in the residual phase in both ditch and riparian wetland soils, and the residual proportions generally increased with depth. Bioconcentration and translocation factors for most of these four heavy metals significantly decreased in the DWs with older age (p<0.05), whereas they increased in the RWs with younger age (p<0.05). The DW soils contained higher concentrations of heavy metals in the organic fractions, whereas there were more carbonate and residual fractions in the RW soils. The non-bioavailable fractions of Cu and Zn, and the organic-bound Cd and Pb significantly inhibited plant growth.

  10. 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.

  11. Spontaneously broken asymptotic symmetries and an effective action for horizon dynamics

    NASA Astrophysics Data System (ADS)

    Eling, Christopher

    2017-02-01

    Asymptotic spacetime symmetries have been conjectured to play an important role in quantum gravity. In this paper we study the breaking of asymptotic symmetries associated with a null horizon boundary. In two-dimensions, these symmetries are reparametrizations of the time parameter on the horizon. We show how this horizon reparametrization symmetry is explicitly and spontaneously broken in dilaton gravity and construct an effective action for these pseudo-Goldstone modes using the on-shell gravitational action for a null boundary. The variation of this action yields the horizon constraint equation. This action is invariant under a 2 parameter subgroup of SL(2) transformations, whose Noether charges we interpret via the membrane paradigm. We place these results in the context of recent work on the near AdS2/ near CFT1 correspondence. In this setting the horizon action characterizes the infrared regime near the horizon and has a hydrodynamical sigma model form. We also discuss our construction in General Relativity. In the three-dimensional case there is a natural generalization of our results. However, in higher dimensions, the variation of the effective action only yields the Raychaudhuri equation for small perturbations of the horizon.

  12. 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.

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. An Optimal Moving Horizon Estimation for Aerial Vehicular Navigation Application

    NASA Astrophysics Data System (ADS)

    Ubaid Gul, Haris; Kai, Yang Dong

    2017-03-01

    In this article, an optimal state is estimated using the moving horizon estimation technique (MHE), based on the minimizing the deterministic cost function defined for moving window with a finite number of samples at specific time interval. The optimal moving horizon observer was designed and implemented for the non-linear dynamic problem of aerial vehicle integrated navigation. The low grade commercial inertial measuring instrument (IMU) equipped with accelerometers and gyros sensors instrumented on-board in the strapdown configuration, is employed for collection of the real time experimental data. The data fusion algorithm of moving horizon estimation is realized and the results are collected from the offline algorithm testing on the Matlab software platform. Essential data processing and cleaning of data processing was conducted before algorithm application i.e. solving the multi rate sensors data synching and removing high frequency unwanted contents. Finally, the aerial vehicle dead reckoning integrated navigation was performed with recursive observer using IMU/GPS avionics. Contrary to the widely practiced extended Kalman filter results, recursive observer of MHE exhibited performance enhancement in the response and precision aspect, regardless of environmental noise and failure scenarios.

  18. Weakly Isolated horizons: first order actions and gauge symmetries

    NASA Astrophysics Data System (ADS)

    Corichi, Alejandro; Reyes, Juan D.; Vukašinac, Tatjana

    2017-04-01

    The notion of Isolated Horizons has played an important role in gravitational physics, being useful from the characterization of the endpoint of black hole mergers to (quantum) black hole entropy. With an eye towards a canonical formulation we consider general relativity in terms of connection and vierbein variables and their corresponding first order actions. We focus on two main issues: (i) The role of the internal gauge freedom that exists, in the consistent formulations of the action principle, and (ii) the role that a 3  +  1 canonical decomposition has in the allowed internal gauge freedom. More concretely, we clarify in detail how the requirement of having well posed variational principles compatible with general weakly isolated horizons (WIHs) as internal boundaries does lead to a partial gauge fixing in the first order descriptions used previously in the literature. We consider the standard Hilbert–Palatini action together with the Holst extension (needed for a consistent 3  +  1 decomposition), with and without boundary terms at the horizon. We show in detail that, for the complete configuration space—with no gauge fixing—, while the Palatini action is differentiable without additional surface terms at the inner WIH boundary, the more general Holst action is not. The introduction of a surface term at the horizon—that renders the action for asymptotically flat configurations differentiable—does make the Holst action differentiable, but only if one restricts the configuration space and partially reduces the internal Lorentz gauge. For the second issue at hand, we show that upon performing a 3  +  1 decomposition and imposing the time gauge, there is a further gauge reduction of the Hamiltonian theory in terms of Ashtekar–Barbero variables to a U(1)-gauge theory on the horizon. We also extend our analysis to the more restricted boundary conditions of (strongly) isolated horizons as inner boundary. We show that even when

  19. New geometries for black hole horizons

    NASA Astrophysics Data System (ADS)

    Armas, Jay; Blau, Matthias

    2015-07-01

    We construct several classes of worldvolume effective actions for black holes by integrating out spatial sections of the worldvolume geometry of asymptotically flat black branes. This provides a generalisation of the blackfold approach for higher-dimensional black holes and yields a map between different effective theories, which we exploit by obtaining new hydrodynamic and elastic transport coefficients via simple integrations. Using Euclidean minimal surfaces in order to decouple the fluid dynamics on different sections of the worldvolume, we obtain local effective theories for ultraspinning Myers-Perry branes and helicoidal black branes, described in terms of a stress-energy tensor, particle currents and non-trivial boost vectors. We then study in detail and present novel compact and non-compact geometries for black hole horizons in higher-dimensional asymptotically flat space-time. These include doubly-spinning black rings, black helicoids and helicoidal p-branes as well as helicoidal black rings and helicoidal black tori in D ≥ 6.

  20. New Developments with the Event Horizon Telescope

    NASA Astrophysics Data System (ADS)

    Fish, Vincent L.; Doeleman, S.; Krichbaum, T.; Zensus, A.; Event Horizon Telescope Collaboration

    2014-01-01

    The Event Horizon Telescope is an international collaboration to observe nearby supermassive black holes with millimeter-wavelength very long baseline interferometry in order to probe the region of the black hole shadow. Previous observations have placed strong constraints on the morphology of the emitting region around Sagittarius A* and the supermassive black hole in the center of M87, resulting in greater insight into the processes of accretion and outflow around black holes. Substantial advances in data quality have been made in the most recent March 2013 observations. Linear polarization has been clearly detected toward a variety of sources on angular scales of tens to hundreds of microarcseconds. Interhemispheric fringes, both North-South and East-West, were obtained, providing the best EHT baseline coverage to date. Technical progress on other stations that may participate in the 1.3 mm VLBI array, including a successful 3 mm VLBI experiment with the Large Millimeter Telescope and continued development of the ALMA beamformer, will soon increase the array sensitivity and baseline coverage, permitting imaging of black holes for the first time.

  1. 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.

  2. Io’s active volcanoes during the New Horizons era: Insights from New Horizons imaging

    NASA Astrophysics Data System (ADS)

    Rathbun, J. A.; Spencer, J. R.; Lopes, R. M.; Howell, R. R.

    2014-03-01

    In February 2007, the New Horizons spacecraft flew by the Jupiter system, obtaining images of Io, the most volcanically active body in the Solar System. The Multicolor Visible Imaging Camera (MVIC), a four-color (visible to near infrared) camera, obtained 17 sets of images. The Long-Range Reconnaissance Imager (LORRI), a high-resolution panchromatic camera, obtained 190 images, including many of Io eclipsed by Jupiter. We present a complete view of the discrete point-like emission sources in all images obtained by these two instruments. We located 54 emission sources and determined their brightnesses. These observations, the first that observed individual Ionian volcanoes on short timescales of seconds to minutes, demonstrate that the volcanoes have stable brightnesses on these timescales. The active volcanoes Tvashtar (63N, 124W) and E. Girru (22N, 245W) were observed by both LORRI and MVIC, both in the near-infrared (NIR) and methane (CH4) filters. Tvashtar was additionally observed in the red filter, which allowed us to calculate a color temperature of approximately 1200 K. We found that, with some exceptions, most of the volcanoes frequently active during the Galileo era continued to be active during the New Horizons flyby. We found that none of the seven volcanoes observed by New Horizons multiple times over short timescales showed substantial changes on the order of seconds and only one, E. Girru exhibited substantial variation over minutes to days, increasing by 25% in just over an hour and decreasing by a factor of 4 over 6 days. Observations of Tvashtar are consistent with a current eruption similar to previously observed eruptions and are more consistent with the thermal emission of a lava flow than the fire fountains inferred from the November 1999 observations. These data also present new puzzles regarding Ionian volcanism. Since there is no associated surface change or low albedo feature that could be identified nearby, the source of the emission from

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Does horizon entropy satisfy a quantum null energy conjecture?

    NASA Astrophysics Data System (ADS)

    Fu, Zicao; Marolf, Donald

    2016-12-01

    A modern version of the idea that the area of event horizons gives 4G times an entropy is the Hubeny-Rangamani causal holographic information (CHI) proposal for holographic field theories. Given a region R of a holographic QFTs, CHI computes A/4G on a certain cut of an event horizon in the gravitational dual. The result is naturally interpreted as a coarse-grained entropy for the QFT. CHI is known to be finitely greater than the fine-grained Hubeny-Rangamani-Takayanagi (HRT) entropy when \\partial R lies on a Killing horizon of the QFT spacetime, and in this context satisfies other non-trivial properties expected of an entropy. Here we present evidence that it also satisfies the quantum null energy condition (QNEC), which bounds the second derivative of the entropy of a quantum field theory on one side of a non-expanding null surface by the flux of stress-energy across the surface. In particular, we show CHI to satisfy the QNEC in 1  +  1 holographic CFTs when evaluated in states dual to conical defects in AdS3. This surprising result further supports the idea that CHI defines a useful notion of coarse-grained holographic entropy, and suggests unprecedented bounds on the rate at which bulk horizon generators emerge from a caustic. To supplement our motivation, we include an appendix deriving a corresponding coarse-grained generalized second law for 1  +  1 holographic CFTs perturbatively coupled to dilaton gravity.

  8. Horizon thermodynamics in fourth-order gravity

    NASA Astrophysics Data System (ADS)

    Ma, Meng-Sen

    2017-03-01

    In the framework of horizon thermodynamics, the field equations of Einstein gravity and some other second-order gravities can be rewritten as the thermodynamic identity: dE = TdS - PdV. However, in order to construct the horizon thermodynamics in higher-order gravity, we have to simplify the field equations firstly. In this paper, we study the fourth-order gravity and convert it to second-order gravity via a so-called ;Legendre transformation; at the cost of introducing two other fields besides the metric field. With this simplified theory, we implement the conventional procedure in the construction of the horizon thermodynamics in 3 and 4 dimensional spacetime. We find that the field equations in the fourth-order gravity can also be written as the thermodynamic identity. Moreover, we can use this approach to derive the same black hole mass as that by other methods.

  9. 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.

  10. Global and local horizon quantum mechanics

    NASA Astrophysics Data System (ADS)

    Casadio, Roberto; Giugno, Andrea; Giusti, Andrea

    2017-02-01

    Horizons are classical causal structures that arise in systems with sharply defined energy and corresponding gravitational radius. A global gravitational radius operator can be introduced for a static and spherically symmetric quantum mechanical matter state by lifting the classical "Hamiltonian" constraint that relates the gravitational radius to the ADM mass, thus giving rise to a "horizon wave-function". This minisuperspace-like formalism is shown here to be able to consistently describe also the local gravitational radius related to the Misner-Sharp mass function of the quantum source, provided its energy spectrum is determined by spatially localised modes.

  11. Horizon detection and higher dimensional black rings

    NASA Astrophysics Data System (ADS)

    Coley, A. A.; McNutt, D. D.

    2017-02-01

    In this paper we study the stationary horizons of the rotating black ring and the supersymmetric black ring spacetimes in five dimensions. In the case of the rotating black ring we use Weyl aligned null directions to algebraically classify the Weyl tensor, and utilize an adapted Cartan algorithm in order to produce Cartan invariants. For the supersymmetric black ring we employ the discriminant approach and repeat the adapted Cartan algorithm. For both of these metrics we are able to construct Cartan invariants that detect the horizon alone, and which are easier to compute and analyse than scalar polynomial curvature invariants.

  12. 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.

  13. Classification of Near-Horizon Geometries of Extremal Black Holes.

    PubMed

    Kunduri, Hari K; Lucietti, James

    2013-01-01

    Any spacetime containing a degenerate Killing horizon, such as an extremal black hole, possesses a well-defined notion of a near-horizon geometry. We review such near-horizon geometry solutions in a variety of dimensions and theories in a unified manner. We discuss various general results including horizon topology and near-horizon symmetry enhancement. We also discuss the status of the classification of near-horizon geometries in theories ranging from vacuum gravity to Einstein-Maxwell theory and supergravity theories. Finally, we discuss applications to the classification of extremal black holes and various related topics. Several new results are presented and open problems are highlighted throughout.

  14. Find Your College's Strategic Horizon

    ERIC Educational Resources Information Center

    Alfred, Richard L.

    2004-01-01

    Community colleges are experiencing tough times. As leaders watch the economy jump back to life and recognize this as a time of opportunity, they also realize that recovery in the public sector lags behind. Community colleges expecting to emerge from reduction stronger and better positioned will need to operate outside of a conventional business…

  15. Do Forest Age and Soil Depth Affect Carbon and Nitrogen Adsorption in Mineral Horizons?

    NASA Astrophysics Data System (ADS)

    Spina, P. G.; Lovett, G. M.; Fuss, C. B.; Goodale, C. L.; Lang, A.; Fahey, T.

    2015-12-01

    Mineral soils retain large amounts of organic matter through sorption on the surfaces of mineral soils, the largest pools of carbon (C) and nitrogen (N) in the forests of the northeastern U.S. In addition to determining organic matter storage, adsorption and desorption processes are important controllers of runoff chemistry. We are studying adsorption dynamics of mineral soils collected from a chronosequence of hardwood forest sites in the White Mountains, NH to determine how soils vary in their DOM adsorption capacities as a function of effective C and N saturation. We hypothesize that forest age determines proximity to saturation because young forests may need to mine soil organic matter (SOM) in mineral soils to obtain nitrogen to meet growth demands, while the soils of older forests have had time to reaccumulate SOM, eventually reaching C and N saturation. Consequently, we expect adsorption capacities to first increase with forest age in young forests, as the trees mine C and N from mineral surfaces. They will then decrease with forest age in older forests as mining slows and C and N begin to re-accumulate. Batch experiments were conducted with mineral soil samples and dilutions of forest floor leachate. However, preliminary results from a mature forest site (about 100 years old), which we predicted to be a low point of C and N saturation from decades of mining, contradict expectations. Dissolved organic carbon (DOC) adsorption in its shallow mineral soil layers (0-3 cm below E or A horizons) are lower than younger sites ranging from 20 to about 40 years old. In addition to forest age, soil depths also affect N retention dynamics in forest soils. We hypothesized that deeper mineral soils might have greater adsorption capacities due to the fact that they are exposed to less DOC and DON leaching from organic layers and therefore less saturated. Results from the same mature forest site confirm this. Soils from 3-10 cm depth have more potential to adsorb DOC and

  16. 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…

  17. Senior Adult Bands: Music's New Horizon.

    ERIC Educational Resources Information Center

    Coffman, Don D.; Levy, Katherine M.

    1997-01-01

    Discusses the success of Iowa City's (Iowa) New Horizons Band that consists of 55 senior adult beginners and former instrumentalists. Describes the organization of the band program, the senior's performance skills and commitment, and the ongoing challenges. Gives a selected listing of the music the band plays at concerts and other events. (CMK)

  18. Teachers' Beliefs about Mathematical Horizon Content Knowledge

    ERIC Educational Resources Information Center

    Mosvold, Reidar; Fauskanger, Janne

    2014-01-01

    In this article, we present and discuss an example of how teachers' discussions of mathematical knowledge for teaching (MKT) items elicited their beliefs about the knowledge needed to teach mathematics. One category of MKT is "horizon content knowledge," and this can be described as mathematical knowledge not directly deployed in…

  19. HIGHER HORIZONS, A PROGRAM FOR YOUR CHILD.

    ERIC Educational Resources Information Center

    New York City Board of Education, Brooklyn, NY.

    PARENTS ARE TOLD THAT HIGHER HORIZONS WILL HELP DEVELOP THE CAPACITIES OF EVERY CHILD, INCREASE HIS SELF CONFIDENCE, AND HELP HIM COMPLETE HIGH SCHOOL. RESULTS OF TESTS AND INTERVIEWS TO DISCOVER A CHILD'S ABILITIES, INTERESTS, AND NEEDS ARE DISCUSSED IN PARENT-TEACHER CONFERENCES. INSTRUCTION IS AIMED AT DEVELOPING ABILITIES. THE CHILD IS…

  20. 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.

  1. 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…

  2. Finite Horizon H Infinity with Parameter Variations

    DTIC Science & Technology

    1992-05-01

    International Journal of Robust and Nonlinear Control, to appear. SUBRAHMANYAM, M. B., 1992d, Worst-case optimal control over a finite horizon, Journal of Mathematical Analysis and Applications , to...in linear systems, Journal of Mathematical Analysis and Applications , 164, 130-150. SUBRAHMANYAM, M. B., 1991, H, 0 optimal control theory over a

  3. Sighting Horizons of Teaching in Higher Education

    ERIC Educational Resources Information Center

    Barnett, Ronald; Guzmán-Valenzuela, Carolina

    2017-01-01

    This conceptual paper tackles the matter of teaching in higher education and proposes a concept of "horizons of teaching." It firstly offers an overview of the considerable empirical literature around teaching--especially conceptions of teaching, approaches to teaching and teaching practices--and goes on to pose some philosophical and…

  4. 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…

  5. Soft hairs on isolated horizon implanted by electromagnetic fields

    NASA Astrophysics Data System (ADS)

    Mao, Pujian; Wu, Xiaoning; Zhang, Hongbao

    2017-03-01

    Inspired by the recent proposal of soft hair on black holes in Hawking et al (2016 Phys. Rev. Lett. 116 231301), we have shown that an isolated horizon carries soft hairs implanted by electromagnetic fields. The solution space and the asymptotic symmetries of Einstein–Maxwell theory have been worked out explicitly near the isolated horizon. The conserved current has been computed and an infinite number of near horizon charges have been introduced from the electromagnetic fields associated with the asymptotic U(1) symmetry near the horizon, which indicates the fact that the isolated horizon carries a large amount of soft electric hairs. The soft electric hairs, i.e. asymptotic U(1) charges, are shown to be equivalent to the electric multipole moments of isolated horizons. It is further argued that the isolated horizon supertranslation is from the ambiguity of its foliation and an analogue of memory effect on horizon can be expected.

  6. 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...

  7. 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 ...

  8. 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.

  9. 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…

  10. Multi-Bandwidth GPR Profiles of Granite in New Hampshire: Attributes of Fracture Horizons and Wavelets

    NASA Astrophysics Data System (ADS)

    Arcone, S. A.; Campbell, S. W.

    2012-12-01

    Sheet and tectonic fractures transport water and facilitate erosion on geologic time scales. We discuss ground-penetrating radar profiles of fractures recorded with 150, 350, 600 and 1000 MHz pulse dominant frequencies, and quantitative data obtained from their horizons and pulse wavelet attributes. We recorded the profiles along dirt roads and bare rock transects, beneath which include the mid Ordovician Oliverian granodiorite and binary granite of western New Hampshire and just north of the Presidential Range, respectively, and the late Devonian biotite granite just west of the Presidential Range. The overriding till is characterized by numerous diffractions, and from 0 to about 5 m thick. We use a known relative dielectric permittivity of 6.6 for granodiorite and assume the same for the other types to calibrate depth from the reflection time scale. Dielectric permittivity values for the till range from about 13-21. The sheet fracture responses are up to 25 m deep while the deepest tectonic fracture horizon extends to at least 35 m depth. Some horizons are associated with numerous diffractions originating along their length, while others have very few. The less clear horizons recorded in seasonal profiles of the binary granite suggest grusification, a possible factor to help explain the greater height of the more durable metamorphic Presidential Range. Sheet fracture spacing can be closer than one meter, with horizons comprised of thin layer responses because the wavelets, even at 1000 MHz, are similar to the transmitted wavelet. Therefore, the fractures are likely less than a few cm thick, as is apparent from quarry wall exposures, and from models that predict that even one mm fractures are detectable. The wavelet phase structure generally indicates a higher dielectric medium, which could mean calcite, and more likely water, but this structure is not consistent along individual horizons. The higher frequency profiles reveal a complex fracture network that

  11. Destination pluto: New horizons performance during the approach phase

    NASA Astrophysics Data System (ADS)

    Flanigan, Sarah H.; Rogers, Gabe D.; Guo, Yanping; Kirk, Madeline N.; Weaver, Harold A.; Owen, William M.; Jackman, Coralie D.; Bauman, Jeremy; Pelletier, Frederic; Nelson, Derek; Stanbridge, Dale; Dumont, Phillip J.; Williams, Bobby; Stern, S. Alan; Olkin, Cathy B.; Young, Leslie A.; Ennico, Kimberly

    2016-11-01

    The New Horizons spacecraft began its journey to the Pluto-Charon system on January 19, 2006 on-board an Atlas V rocket from Cape Canaveral, Florida. As the first mission in NASA's New Frontiers program, the objective of the New Horizons mission is to perform the first exploration of ice dwarfs in the Kuiper Belt, extending knowledge of the solar system to include the icy "third zone" for the first time. Arriving at the correct time and correct position relative to Pluto on July 14, 2015 depended on the successful execution of a carefully choreographed sequence of events. The Core command sequence, which was developed and optimized over multiple years and included the highest-priority science observations during the closest approach period, was contingent on precise navigation to the Pluto-Charon system and nominal performance of the guidance and control (G&C) subsystem. The flyby and gravity assist of Jupiter on February 28, 2007 was critical in placing New Horizons on the path to Pluto. Once past Jupiter, trajectory correction maneuvers (TCMs) became the sole source of trajectory control since the spacecraft did not encounter any other planetary bodies along its flight path prior to Pluto. During the Pluto approach phase, which formally began on January 15, 2015, optical navigation images were captured primarily with the Long Range Reconnaissance Imager to refine spacecraft and Pluto-Charon system trajectory knowledge, which in turn was used to design TCMs. Orbit determination solutions were also used to update the spacecraft's on-board trajectory knowledge throughout the approach phase. Nominal performance of the G&C subsystem, accurate TCM designs, and high-quality orbit determination solutions resulted in final Pluto-relative B-plane arrival conditions that facilitated a successful first reconnaissance of the Pluto-Charon system.

  12. The Thermodynamic Evolution of the Cosmological Event Horizon

    NASA Astrophysics Data System (ADS)

    Funkhouser, Scott

    2012-04-01

    By manipulating the integral expression for the proper radius R e of the cosmological event horizon (CEH) in a Friedmann-Robertson-Walker (FRW) universe we obtain an analytical expression for the change δR e in response to a uniform fluctuation δρ in the average cosmic background density ρ. We stipulate that the fluctuation arises within a vanishing interval of proper time, during which the CEH is approximately stationary, and evolves subsequently such that δρ/ ρ is constant. The respective variations 2 πR e δR e and δE e in the horizon entropy S e and enclosed energy E e should be therefore related through the cosmological Clausius relation. In that manner we find that the temperature T e of the CEH at an arbitrary time in a flat FRW universe is E e / S e , which recovers asymptotically the usual static de Sitter temperature. Furthermore it is proven that during radiation-dominance and in late times the CEH conforms to the fully dynamical First Law T e d S e = Pd V e -d E e , where V e is the enclosed volume and P is the average cosmic pressure.

  13. 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

  14. 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.

  15. The problem of the maximum volumes and particle horizon in the Friedmann universe model

    NASA Astrophysics Data System (ADS)

    Gong, S. M.

    1989-08-01

    The maximum volume of the closed Friedmann universe is further investigated and is shown to be 2 x pi squared x R cubed (t), instead of pi squared x R cubed (t) as found previously. This discrepancy comes from the incomplete use of the volume formula of 3-dimensional spherical space in the astronomical literature. Mathematically, the maximum volume exists at any cosmic time t in a 3-dimensional spherical case. However, the Friedmann closed universe in expansion reaches its maximum volume only at the time of the maximum scale factor. The particle horizon has no limitation for the farthest objects in the closed Friedmann universe if the proper distance of objects is compared with the particle horizon as is should be. This leads to absurdity if the luminosity distance of objects is compared with the proper distance of the particle horizon.

  16. Fiber-optical analog of the event horizon.

    PubMed

    Philbin, Thomas G; Kuklewicz, Chris; Robertson, Scott; Hill, Stephen; König, Friedrich; Leonhardt, Ulf

    2008-03-07

    The physics at the event horizon resembles the behavior of waves in moving media. Horizons are formed where the local speed of the medium exceeds the wave velocity. We used ultrashort pulses in microstructured optical fibers to demonstrate the formation of an artificial event horizon in optics. We observed a classical optical effect: the blue-shifting of light at a white-hole horizon. We also showed by theoretical calculations that such a system is capable of probing the quantum effects of horizons, in particular Hawking radiation.

  17. 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

  18. Rogue events in the group velocity horizon.

    PubMed

    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.

  19. 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.

  20. Polarimetry with the Event Horizon Telescope

    NASA Astrophysics Data System (ADS)

    Johnson, Michael; Doeleman, Sheperd; Fish, Vincent L.; Plambeck, Richard L.; Marrone, Daniel P.; Kosowsky, Michael; Wardle, John F. C.; Lu, Rusen

    2014-06-01

    The Event Horizon Telescope (EHT) is an effort to develop millimeter and submillimeter VLBI to image nearby black holes at resolutions comparable to their event horizons. Past work with the EHT has measured compact emission on such scales for Sgr A* and M87, and has also measured sub-parsec structure in more distant quasars. Polarimetry with the EHT enables a powerful extension of this work, mapping magnetic field structures via the highly polarized synchrotron emission. Polarization is also an excellent probe of rapid variability, especially for Sgr A*, and can convey rich astrometric information even with incomplete imaging. We report on results from our 2013 campaign, which demonstrate a sharp increase in the linear polarization fraction and variability with increasing baseline, and we demonstrate that current EHT data can potentially achieve microarcsecond relative astrometry of flaring regions on timescales of minutes.

  1. Cosmo-geo-anthropo-logical history and political and deep future events in climate and life evolution conveyed by a physical/virtual installation at a scale of 1 mm per 100 years across Denmark during the COP15 climate summit meeting.

    NASA Astrophysics Data System (ADS)

    Holm Jacobsen, Bo

    2010-05-01

    During the COP15 climate summit meeting a physical and virtual installation of time was performed at a linear scale of 1 mm per 100 years. The "track of time" was carefully anchored geographically so that highlights in time history coincided with landmarks of historical and cultural significance to both tourists and the local Danish population; with Big Bang at the site of early royal settlements from the Viking age (13.7 billion years ~ 137 km from now), Earth origin at Kronborg in Elsinore (4.6 bil. Years ~ 46 km), and fish go on land at The Little Mermaid (390 mil. Years ~ 3900 m). The venue of the COP15 meeting coincided with the position of severe global warming, driven by the steady solar constant increase, to be expected 600 million years into the future. Nested in this grand track of time were the Quaternary ice-ages (2.6 mil. years ~ 26 m), human origin as species (100,000 years ~ 1 m), human history (< 10,000 years ~ 100 mm), personal life and the scope of political consequences of voting action (100 years ~ 1 mm). This installation of time involved several media. Highlights in time history and future were installed as a kml-file so that the convenient user interface of Google Earth could be utilized to provide both overview of time and understanding of details and proportions events antropo-geo-cosmo-history. Each Google Earth marker-balloon gave short explanations and linked to "on location" video-narratives. A classical printed text-folder was prepared as a tour guide for those who wanted to actually walk the Phanerozoic (~5 km). Credit-card-shaped graphs of temperature, CO2 and sealevel development and scenarios were prepared to scale for the period 4000 BP to 1000 years into the future. Along the time line from "Fish on land" to the present 3900 chalk marks were placed on the street surface, one for every metre = time span of Man as a species so far. A "NowGate" marking the present was implemented physically as a door frame, where citizens could meet

  2. "I want to be 100 years old, but I smoke too much": Exploring the gap between positive aging goals and reported preparatory actions in different social circumstances.

    PubMed

    Craciun, Catrinel; Flick, Uwe

    2015-12-01

    Preparing for positive aging is shaped by the social context a person lives in. The present qualitative study explores and compares representations about preparatory actions in precarious workers (i.e., with temporary job contracts and insecure pension plans) and individuals with secure pension plans living in Germany. It also examines, the discrepancy between what middle-aged persons think they should be doing in preparation and what they report doing for aging well. Findings from the analysis of the semi-structured interviews conducted here show that people who have insecure pension plans tend to see themselves as social networkers and optimists, while those with secure pension plans see themselves as social activists and careful planners of old age. All participants value an active, healthy body but manage to do little in order to attain it due to lacking time and discipline. In accordance with the socioemotional selectivity theory, perceiving a short-time perspective makes precarious individuals focus on emotional goals, while financially secure individuals value social goals. Implications for practice and policy change are discussed.

  3. Quantum amplification effect in a horizon fluctuation

    SciTech Connect

    Ansari, Mohammad H.

    2010-05-15

    The appearance of a few unevenly spaced bright flashes of light on top of Hawking radiation is the sign of the amplification effect in black hole horizon fluctuations. Previous studies on this problem suffer from the lack of considering all emitted photons in the theoretical spectroscopy of these fluctuations. In this paper, we include all of the physical transition weights and present a consistent intensity formula. This modifies a black hole radiation pattern.

  4. Gribov horizon beyond the Landau gauge

    NASA Astrophysics Data System (ADS)

    Lavrov, Peter M.; Lechtenfeld, Olaf

    2013-10-01

    Gribov and Zwanziger proposed a modification of Yang-Mills theory in order to cure the Gribov copy problem. We employ field-dependent BRST transformations to generalize the Gribov-Zwanziger model from the Landau gauge to general Rξ gauges. The Gribov horizon functional is presented in explicit form, in both the non-local and local variants. Finally, we show how to reach any given gauge from the Landau one.

  5. New horizons in ambulatory electroencephalography.

    PubMed

    Waterhouse, Elizabeth

    2003-01-01

    Since its inception 30 years ago, AEEG has continued to evolve--from four-channel tape recorders to 32-channel digital recorders with sophisticated automatic spike and seizure detection algorithms. AEEG remains an important tool in epilepsy evaluation. In the near future, smaller, faster, and more sophisticated AEEGs will be developed. Seizure detection/anticipation systems will allow the wearer to be forewarned of a seizure so that appropriate safety measures can be taken. With further refinement in our understanding of nonlinear dynamic analysis to define the pre-ictal state, AEEG will be coupled with an accurate seizure anticipation device in a closed-loop system, providing a time window during which therapeutic intervention can occur, to prevent a seizure. The therapeutic intervention will most likely involve vagus nerve or deep brain stimulation. An alternative is that the patient may learn to recognize early symptoms of the pre-ictal state and use behavioral biofeedback interventions to avoid a clinical seizure. In order to achieve convenient ambulatory recording and seizure detection that could realistically improve the lives of patients with refractory epilepsy, the process of miniaturization of such a device to a convenient size must be accomplished. One of the aspects of epilepsy that patients find most frustrating, and that most limits activities, is the vulnerability to sudden unexpected incapacitation due to the occurrence of a seizure. With miniaturization of AEEG and seizure anticipation technology, and advancements in our ability to identify the transition from pre-ictal to ictal state, there is realistic hope that patients with refractory epilepsy may gain control over their seizures and enjoy significantly improved quality of life.

  6. 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.

  7. Towards Assessing the Human Trajectory Planning Horizon

    PubMed Central

    Nitsch, Verena; Meinzer, Dominik; Wollherr, Dirk

    2016-01-01

    Mobile robots are envisioned to cooperate closely with humans and to integrate seamlessly into a shared environment. For locomotion, these environments resemble traversable areas which are shared between multiple agents like humans and robots. The seamless integration of mobile robots into these environments requires accurate predictions of human locomotion. This work considers optimal control and model predictive control approaches for accurate trajectory prediction and proposes to integrate aspects of human behavior to improve their performance. Recently developed models are not able to reproduce accurately trajectories that result from sudden avoidance maneuvers. Particularly, the human locomotion behavior when handling disturbances from other agents poses a problem. The goal of this work is to investigate whether humans alter their trajectory planning horizon, in order to resolve abruptly emerging collision situations. By modeling humans as model predictive controllers, the influence of the planning horizon is investigated in simulations. Based on these results, an experiment is designed to identify, whether humans initiate a change in their locomotion planning behavior while moving in a complex environment. The results support the hypothesis, that humans employ a shorter planning horizon to avoid collisions that are triggered by unexpected disturbances. Observations presented in this work are expected to further improve the generalizability and accuracy of prediction methods based on dynamic models. PMID:27936015

  8. New Horizons Imaging of Jupiter's Main Ring

    NASA Astrophysics Data System (ADS)

    Throop, Henry B.; Showalter, Mark Robert; Dones, Henry C. Luke; Hamilton, D. P.; Weaver, Harold A.; Cheng, Andrew F.; Stern, S. Alan; Young, Leslie; Olkin, Catherine B.; New Horizons Science Team

    2016-10-01

    New Horizons took roughly 520 visible-light images of Jupiter's ring system during its 2007 flyby, using the spacecraft's Long-Range Reconnaissance Imager (LORRI). These observations were taken over nine days surrounding Jupiter close-approach. They span a range in distance of 30 - 100 RJ, and a phase angle range of 20 - 174 degrees. The highest resolution images -- more than 200 frames -- were taken at a resolution approaching 20 km/pix.We will present an analysis of this dataset, much of which has not been studied in detail before. Our results include New Horizons' first quantitative measurements of the ring's intrinsic brightness and variability. We will also present results on the ring's azimuthal and radial structure. Our measurements of the ring's phase curve will be used to infer properties of the ring's dust grains.Our results build on the only previous analysis of the New Horizons Jupiter ring data set, presented in Showalter et al (2007, Science 318, 232-234), which detected ring clumps and placed a lower limit on the population of undetected ring-moons.This work was supported by NASA's OPR program.

  9. The Event Horizon of M87

    NASA Astrophysics Data System (ADS)

    Broderick, Avery E.; Narayan, Ramesh; Kormendy, John; Perlman, Eric S.; Rieke, Marcia J.; Doeleman, Sheperd S.

    2015-06-01

    The 6× {{10}9} {{M}⊙ } supermassive black hole at the center of the giant elliptical galaxy M87 powers a relativistic jet. Observations at millimeter wavelengths with the Event Horizon Telescope have localized the emission from the base of this jet to angular scales comparable to the putative black hole horizon. The jet might be powered directly by an accretion disk or by electromagnetic extraction of the rotational energy of the black hole. However, even the latter mechanism requires a confining thick accretion disk to maintain the required magnetic flux near the black hole. Therefore, regardless of the jet mechanism, the observed jet power in M87 implies a certain minimum mass accretion rate. If the central compact object in M87 were not a black hole but had a surface, this accretion would result in considerable thermal near-infrared and optical emission from the surface. Current flux limits on the nucleus of M87 strongly constrain any such surface emission. This rules out the presence of a surface and thereby provides indirect evidence for an event horizon.

  10. 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

  11. Miklós Konkoly Thege (1842-1916). 100 Years of Observational Astronomy and Astrophysics - A collection of papers on the history of Observational Astrophysics.

    NASA Astrophysics Data System (ADS)

    Sterken, C.; Hearnshaw, J. B.

    2001-10-01

    This book results from presentations and discussions by a group of astronomers and historians during a three-day workshop held at Tihany (Hungary), on 13-15 August 1999. This meeting - the second forum dedicated to the rise of observational astrophysics in the nineteenth and early twentieth century - coincided with the centenary of Hungary's national observatory. The basic principle of this series of meetings is to reflect on the work and personality of a single individual or of a group of persons, at the same time avoiding the really dominant figures that typify the age. The series focuses on key people who epitomize a way of thinking and working, that has in turn formed many of the ideas by which we do astrophysical research today. Hence the evocation of the scientific spirit of the era under consideration is attempted. Such a leading key person undoubtedly was Miklós Konkoly Thege. A superb instrumentalist and observer, Konkoly became the founding father of Hungarian astronomy through the establishment of his private observatory that later became the Royal Hungarian Ógyalla Observatory, the precursor of the modern Konkoly Observatory. The workshop was organized at the occasion of the centennial anniversary of Konkoly Observatory. The book outlines five major themes. The first part describes the birth of observational astrophysics in Hungary and focuses on historical aspects of 19th century Hungarian astronomy from three different viewpoints: the historical narrative based on historical facts, the perspective as seen by an expert in historical instrumentation, and a discussion of the socio-political consequences of nineteenth-century developments for our present times. The second part analyses the birth of observational astrophysics in countries with which Konkoly and his collaborators had close contacts: Japan, South Africa and France. The third part of the book discusses the establishment of the discipline of photometry worldwide. An important aspect of 19th

  12. Temporal and Spatial Variations in Volcanic Accretion Over the Past Few 100 Years on the EPR Axis at Superfast Spreading rates at 17 to 18 deg S

    NASA Astrophysics Data System (ADS)

    Rubin, K. H.; Sinton, J. M.; Bergmanis, E. C.

    2008-12-01

    cuts the axis of a broadly inflated ridge segment. The contrast in across-axis profile of these two segments indicates that magma supply can vary locally over short time periods, even at these very high spreading rates. Data on lava flow volumes and ages indicate that time integrated magma accumulation rates and eruption recurrence intervals are broadly similar to those at other ridges where repeat eruptions have been mapped and sampled (N-EPR and the Juan de Fuca Ridge), although data are sparse at all of these locales. There are clear long-term differences in magma supply to these regions, implying that recent volcanic production rates measured at a particular site may exceed or fall short of long- term magma supply rates there.

  13. 100 years of occupational safety research: From basic protections and work analysis to a multilevel view of workplace safety and risk.

    PubMed

    Hofmann, David A; Burke, Michael J; Zohar, Dov

    2017-03-01

    Starting with initiatives dating back to the mid-1800s, we provide a high-level review of the key trends and developments in the application of applied psychology to the field of occupational safety. Factory laws, basic worker compensation, and research on accident proneness comprised much of the early work. Thus, early research and practice very much focused on the individual worker, the design of their work, and their basic protection. Gradually and over time, the focus began to navigate further into the organizational context. One of the early efforts to broaden beyond the individual worker was a significant focus on safety-related training during the middle of the 20th century. Toward the latter years of the 20th century and continuing the move from the individual worker to the broader organizational context, there was a significant increase in leadership and organizational climate (safety climate) research. Ultimately, this resulted in the development of a multilevel model of safety culture/climate. After discussing these trends, we identify key conclusions and opportunities for future research. (PsycINFO Database Record

  14. 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

  15. 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.

  16. Loop quantum cosmology: The horizon problem and the probability of inflation

    NASA Astrophysics Data System (ADS)

    Chen, Long; Zhu, Jian-Yang

    2015-10-01

    Anomaly-free perturbations of loop quantum cosmology reveal a deformed space-time structure, in which the signature changes when the energy density is ρ =ρc/2 . Furthermore, in loop quantum cosmology, one can obtain an effective causal structure only for a low density region (ρ ≤ρc/2 ), which gives a natural initial condition to consider the horizon problem. Choosing the initial value at ρ (0 )=ρc/2 in this paper, we investigate the horizon problem and the probability of inflation in the framework of loop quantum cosmology. Two models are considered: the quadratic inflation and the natural inflation. We use the Liouville measure to calculate the probability of inflation which solves the horizon problem, and find that, for the quadratic inflation model, the probability is very close to unity, while for the natural inflation model, the probability is about 35%.

  17. 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.

  18. Inner boundary conditions for black hole initial data derived from isolated horizons

    NASA Astrophysics Data System (ADS)

    Jaramillo, José Luis; Gourgoulhon, Eric; Marugán, Guillermo A.

    2004-12-01

    We present a set of boundary conditions for solving the elliptic equations in the initial data problem for space-times containing a black hole, together with a number of constraints to be satisfied by the otherwise freely specifiable standard parameters of the conformal thin sandwich formulation. These conditions altogether are sufficient for the construction of a horizon that is instantaneously in equilibrium in the sense of the isolated horizons formalism. We then investigate the application of these conditions to the initial data problem of binary black holes and discuss the relation of our analysis with other proposals that exist in the literature.

  19. 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

  20. 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.

  1. Long-Range Reconnaissance Imager on New Horizons

    NASA Astrophysics Data System (ADS)

    Cheng, A. F.; Weaver, H. A.; Conard, S. J.; Morgan, M. F.; Barnouin-Jha, O.; Boldt, J. D.; Cooper, K. A.; Darlington, E. H.; Grey, M. P.; Hayes, J. R.; Kosakowski, K. E.; Magee, T.; Rossano, E.; Sampath, D.; Schlemm, C.; Taylor, H. W.

    2008-10-01

    The LOng-Range Reconnaissance Imager (LORRI) is the high-resolution imaging instrument for the New Horizons mission to Pluto, its giant satellite Charon, its small moons Nix and Hydra, and the Kuiper Belt, which is the vast region of icy bodies extending roughly from Neptune’s orbit out to 50 astronomical units (AU). New Horizons launched on January 19, 2006, as the inaugural mission in NASA’s New Frontiers program. LORRI is a narrow-angle (field of view=0.29°), high-resolution (4.95 μrad pixels), Ritchey-Chrétien telescope with a 20.8-cm diameter primary mirror, a focal length of 263 cm, and a three-lens, field-flattening assembly. A 1,024×1,024 pixel (optically active region), thinned, backside-illuminated charge-coupled device (CCD) detector is used in the focal plane unit and is operated in frame-transfer mode. LORRI provides panchromatic imaging over a bandpass that extends approximately from 350 nm to 850 nm. LORRI operates in an extreme thermal environment, situated inside the warm spacecraft with a large, open aperture viewing cold space. LORRI has a silicon carbide optical system, designed to maintain focus over the operating temperature range without a focus adjustment mechanism. Moreover, the spacecraft is thruster-stabilized without reaction wheels, placing stringent limits on the available exposure time and the optical throughput needed to satisfy the measurement requirements.

  2. Can semi-classical wormholes solve the cosmological horizon problem

    SciTech Connect

    Hochberg, D.; Kephart, T.W. )

    1994-02-01

    Measurements of the cosmic microwave background (CMB) radiation provide the strongest evidence for the isotropy of the observable universe on the largest scales. However, the CMB is received from regions which were not in casual contact at the time of last scattering. This is the horizon problem and the generally accepted solution is to invoke an inflationary period in the early universe. The authors consider the possibility that the universe did not necessarily inflate, but was filled with a network of evolving wormholes connecting otherwise casually disjoint regions. These wormholes emerged naturally from the Planck epoch and need only have stayed open for a very brief time ([delta]t < 10[sup [minus]34] sec) in order to have thermalized the early universe. 13 refs.

  3. 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.…

  4. Native Education: The Next 100 Years.

    ERIC Educational Resources Information Center

    Atleo, E. R.

    This paper discusses the history and trauma of Native education in Canada and stresses the importance of integrating the best of the Native culture with the best of the Western culture in future Native education. The paper is organized in three parts. The first section acknowledges the trauma inflicted on the indigenous peoples by means of early…

  5. 100 Years Werner Heisenberg: Works and Impact

    NASA Astrophysics Data System (ADS)

    Papenfuß, Dietrich; Lüst, Dieter; Schleich, Wolfgang P.

    2003-09-01

    Over 40 renowned scientists from all around the world discuss the work and influence of Werner Heisenberg. The papers result from the symposium held by the Alexander von Humboldt-Stiftung on the occasion of the 100th anniversary of Heisenberg's birth, one of the most important physicists of the 20th century and cofounder of modern-day quantum mechanics. Taking atomic and laser physics as their starting point, the scientists illustrate the impact of Heisenberg's theories on astroparticle physics, high-energy physics and string theory right up to processing quantum information.

  6. The Nightingale pledge: 100 years later.

    PubMed

    McBurney, B H; Filoromo, T

    1994-02-01

    Written in 1893, the Nightingale Pledge reflected the opinion of a small group of nurses, physicians and lay women about the required characteristics of American nursing. This Pledge serves as a professional mission statement, one that truly reflects the deep-seated vision and values of nursing. A modern analysis of this classic work creates a frame of reference to measure nursing practice.

  7. Analysis of 100 Years of Curriculum Designs

    ERIC Educational Resources Information Center

    Kelting-Gibson, Lynn

    2013-01-01

    Fifteen historical and contemporary curriculum designs were analyzed for elements of assessment that support student learning and inform instructional decisions. Educational researchers are purposely paying attention to the role assessment plays in a well-designed planning and teaching process. Assessment is a vital component to educational…

  8. Dairy innovations over the past 100 Years.

    PubMed

    Tunick, Michael H

    2009-09-23

    The dairy industry in the United States has undergone many changes over the past century. Adulteration and contamination of milk were rampant before the passage and enforcement of the Pure Food and Drug Act of 1906, and the introduction and eventual acceptance of certified and pasteurized milk have provided consumers with a consistently safe product. Homogenization and advances in the packaging and transport of milk gradually took hold, improving the milk supply. Other developments included the concentration of milk and whey, lactose-reduced milk, and the popularization of yogurt. Consumers have benefited from advances in butter packaging, low-fat ice cream, cheese manufacture, and yogurt technology, which has helped create the large demand for dairy products in the United States. Current trends and issues, including the increasing popularity of organic and artisanal products and the use of rBST, will shape the future of the dairy industry.

  9. Mendelism in human genetics: 100 years on.

    PubMed

    Majumdar, Sisir K

    2003-01-01

    Genetics (Greek word--'genes' = born) is a science without an objective past. But the genre of genetics was always roaming in the corridors of human psyche since antiquity. The account of heritable deformities in human often appears in myths and legends. Ancient Hindu Caste system was based on the assumption that both desirable and undesirable traits are passed from generation to generation. In Babylonia 60 birth defects were listed on Clay tablets written around 5,000 year ago. The Jewish Talmud contains accurate description of the inheritance of haemophilia--a human genetic disorder. The Upanisads vedant--800--200 BC provides instructions for the choice of a wife emphasizing that no heritable illness should be present and that the family should show evidence of good character for several preceding generations. These examples indicate that heritable human traits played a significant role in social customs are presented in this article.

  10. Spinoff 2003: 100 Years of Powered Flight

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Today, NASA continues to reach milestones in space exploration with the Hubble Telescope, Earth-observing systems, the Space Shuttle, the Stardust spacecraft, the Chandra X-Ray Observatory, the International Space Station, the Mars rovers, and experimental research aircraft these are only a few of the many initiatives that have grown out of NASA engineering know-how to drive the Agency s missions. The technical expertise gained from these programs has transferred into partnerships with academia, industry, and other Federal agencies, ensuring America stays capable and competitive. With Spinoff 2003, we once again highlight the many partnerships with U.S. companies that are fulfilling the 1958 Space Act stipulation that NASA s vast body of scientific and technical knowledge also benefit mankind. This year's issue showcases innovations such as the cochlear implant in health and medicine, a cockpit weather system in transportation, and a smoke mask benefiting public safety; many other products are featured in these disciplines, as well as in the additional fields of consumer/home/recreation, environment and resources management, computer technology, and industrial productivity/ manufactacturing technology. Also in this issue, we devote an entire section to NASA s history in the field of flight and showcase NASA s newest enterprise dedicated to education. The Education Enterprise will provide unique teaching and learning experiences for students and teachers at all levels in science, technology, engineering, and mathematics. The Agency also is committed, as never before, to engaging parents and families through NASA s educational resources, content, and opportunities. NASA s catalyst to intensify its focus on teaching and learning springs from our mission statement: to inspire the next generation of explorers as only NASA can.

  11. Heparin: 100 years of pleiotropic effects.

    PubMed

    Paschoa, Adilson Ferraz

    2016-05-01

    Heparin is a glycosaminoglycan with anticoagulant properties and antiinflammatory effects. The discovery of heparin approaches its 100th year and its antiinflammatory properties still draws much attention and anticipation to new possibilities of use and the likelihood of developing heparin-like drugs that lacked the anticoagulation effects. It is known that heparins limit the embolization and the extension of the thrombus, although they do not promote its complete lysis in most cases. The complexity and pleiotropic characteristics of these glycosaminoglycans still challenge science, to the point in which approaches hitherto unusual appear repeatedly in the literature. New indications, accompanied by longtime consecrated others, dismantle the idea of an outdated medication and create high expectations for the near future. The objective of this review is to analyze the pleiotropic effects of heparin and its use in several diseases, highlighting its safety and effectiveness.

  12. 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.

  13. 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.

  14. New horizons mapping of Europa and Ganymede.

    PubMed

    Grundy, W M; Buratti, B J; Cheng, A F; Emery, J P; Lunsford, A; McKinnon, W B; Moore, J M; Newman, S F; Olkin, C B; Reuter, D C; Schenk, P M; Spencer, J R; Stern, S A; Throop, H B; Weaver, H A

    2007-10-12

    The New Horizons spacecraft observed Jupiter's icy satellites Europa and Ganymede during its flyby in February and March 2007 at visible and infrared wavelengths. Infrared spectral images map H2O ice absorption and hydrated contaminants, bolstering the case for an exogenous source of Europa's "non-ice" surface material and filling large gaps in compositional maps of Ganymede's Jupiter-facing hemisphere. Visual wavelength images of Europa extend knowledge of its global pattern of arcuate troughs and show that its surface scatters light more isotropically than other icy satellites.

  15. An uneventful horizon in two dimensions

    NASA Astrophysics Data System (ADS)

    Almheiri, Ahmed; Sully, James

    2014-02-01

    We investigate the possibility of firewalls in the Einstein-dilaton gravity model of CGHS. We use the results of the numerical simulation carried out by Ashtekar et al. to demonstrate that firewalls are absent and the horizon is drama free. We show that the lack of a firewall is consistent because the model does not satisfy one of the postulates of black hole complementarity. In particular, we elaborate on previous work showing that the Hawking radiation is not pure, and is completely entangled with a long-lived remnant beyond the last ray.

  16. Redshift of a photon emitted along the black hole horizon

    NASA Astrophysics Data System (ADS)

    Toporensky, A. V.; Zaslavskii, O. B.

    2017-03-01

    In this work we derive some general features of the redshift measured by radially moving observers in the black hole background. Let observer 1 cross the black hole horizon emitting a photon, while observer 2 crossing the same horizon later receives it. We show that if (i) the horizon is the outer one (event horizon) and (ii) it is nonextremal, the received frequency is redshifted. This generalizes recent results in the literature. For the inner horizon (like in the Reissner-Nordström metric) the frequency is blueshifted. If the horizon is extremal, the frequency does not change. We derive explicit formulas describing the frequency shift in generalized Kruskal- and Lemaitre-like coordinates.

  17. New Horizons. A National Workplace Literacy Program. Final Report. "New Horizons" External Evaluation Impact Study.

    ERIC Educational Resources Information Center

    Hudson, Patt; Gretes, John A.

    The New Horizons project was a workplace literacy partnership during which 454 employees (53%) of Georgetown Steel attended classes provided by Horry-Georgetown Technical College in Conway, South Carolina. Of the 454 participants, 294 were white, 159 were black, 71 were female, 383 were male, 133 had been with the company for 5 years or less, and…

  18. 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.

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

    PubMed

    Pranzetti, Daniele

    2012-07-06

    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.

  20. 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.

  1. New Horizons in Time Domain Astronomy (IAU S285)

    NASA Astrophysics Data System (ADS)

    Griffin, Elizabeth; Hanisch, Robert; Seaman, Rob

    2012-05-01

    Introduction; Foreword; 1. Can our data meet the challenges?; 2. Explosive or irreversible changes; 3. Things that tick; 4. Irregular and aperiodic changes; 5. Preparing for the future; Workshop reports; Poster papers; Author index.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Numerical examination of an evolving black string horizon

    NASA Astrophysics Data System (ADS)

    Garfinkle, David; Lehner, Luis; Pretorius, Frans

    2005-03-01

    We use the numerical solution describing the evolution of a perturbed black string presented by M. Choptuik, L. Lehner, I. Olabarrieta, R. Petryk, F. Pretorius, and H. Villegas [Phys. Rev. D 68, 044001 (2003)] to elucidate the intrinsic behavior of the horizon. It is found that by the end of the simulation, the affine parameter on the horizon has become very large and the expansion and shear of the horizon in turn very small. This suggests the possibility that the horizon might pinch off in infinite affine parameter.

  7. 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.

  8. THE EVENT HORIZON OF SAGITTARIUS A*

    SciTech Connect

    Broderick, Avery E.; Loeb, Abraham; Narayan, Ramesh

    2009-08-20

    Black hole event horizons, causally separating the external universe from compact regions of spacetime, are one of the most exotic predictions of general relativity. Until recently, their compact size has prevented efforts to study them directly. Here we show that recent millimeter and infrared observations of Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, all but require the existence of a horizon. Specifically, we show that these observations limit the luminosity of any putative visible compact emitting region to below 0.4% of Sgr A*'s accretion luminosity. Equivalently, this requires the efficiency of converting the gravitational binding energy liberated during accretion into radiation and kinetic outflows to be greater than 99.6%, considerably larger than those implicated in Sgr A*, and therefore inconsistent with the existence of such a visible region. Finally, since we are able to frame this argument entirely in terms of observable quantities, our results apply to all geometric theories of gravity that admit stationary solutions, including the commonly discussed f(R) class of theories.

  9. Near-horizon brane-scan revived

    NASA Astrophysics Data System (ADS)

    Duff, M. J.

    2009-03-01

    In 1987 two versions of the brane-scan of D-dimensional super p-branes were put forward. The first pinpointed those (p,D) slots consistent with kappa-symmetric Green-Schwarz type actions; the second generalized the membrane at the end of the universe idea to all those superconformal groups describing p-branes on the boundary of AdS×S. Although the second version predicted D3- and M5-branes in addition to those of the first, it came unstuck because the 1/2 BPS solitonic branes failed to exhibit the required symmetry enhancement in the near-horizon limit, except in the non-dilatonic cases (p=2,D=11), (p=3,D=10) and (p=5,D=11). Just recently, however, it has been argued that the fundamental D=10 heterotic string does indeed display a near-horizon enhancement to OSp(8|2) as predicted by the brane-scan, provided α corrections are taken into account. If this logic could be extended to the other strings and branes, it would resolve this 21-year-old paradox and provide a wealth of new AdS/CFT dualities, which we tabulate.

  10. 50 Years of Soil Survey Horizons

    NASA Astrophysics Data System (ADS)

    Brevik, E. C.

    2012-04-01

    Soil Survey Horizons (SSH) started in 1960 as the newsletter of the North Central Soil Survey, United States, with an editorial board consisting of Francis D. Hole, O.C. Rogers, and Donald F. Post. SSH was started to provide an outlet for field observations of soils because the founders of SSH felt that other outlets for such communications were disappearing. Francis Hole's office at the University of Wisconsin served as the point of publication for SSH through its first 15 years, but in 1975 the Soil Science Society of America (SSSA) began handling its publication. Initially SSSA published SSH but did not assume ownership or editorial control of the publication until 2005. Over the years there has been a steady increase in the amount of material published in each volume of SSH. Significant improvements to Soil Survey Horizons over the years have included a move to full 8.5" x 11" pages and publication in color. Future improvements will include online publication and expansion to an international audience, including recruitement of international members for the editorial board.

  11. Status of the Event Horizon Telescope

    NASA Astrophysics Data System (ADS)

    Fish, Vincent L.; Doeleman, S. S.; Event Horizon Telescope Collaboration

    2011-05-01

    The goal of the Event Horizon Telescope (EHT) project is to understand the physical and astrophysical processes of supermassive black holes though extremely high angular resolution observations. The EHT consists of existing millimeter-wavelength telescopes that participate in very long baseline interferometry (VLBI) observations of Sagittarius A*, M87, and active galactic nuclei. For the nearest sources, the EHT is uniquely capable of providing a resolution of a few Schwarzschild radii. Prior EHT observations have demonstrated very compact structure in Sgr A* and have been used to constrain the orientation of the black hole spin vector, strengthen the case for the existence of an event horizon, and examine the spatial characteristics of the variable millimeter emission. The sensitivity and angular resolution of the array are increasing due to the inclusion of new telescopes and several technical developments currently underway. We will summarize the most recent observations as well as the outlook for further enhancements of the capabilities of the EHT in the near future. This work is funded by grants from the National Science Foundation.

  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. Energy and information near black hole horizons

    NASA Astrophysics Data System (ADS)

    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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Gribov horizon and Gribov copies effect in lattice Coulomb gauge

    NASA Astrophysics Data System (ADS)

    Burgio, Giuseppe; Quandt, Markus; Reinhardt, Hugo; Vogt, Hannes

    2017-01-01

    Following a recent proposal by Cooper and Zwanziger, we investigate via S U (2 ) lattice simulations the effect on the Coulomb gauge propagators and on the Gribov-Zwanziger confinement mechanism of selecting the Gribov copy with the smallest nontrivial eigenvalue of the Faddeev-Popov operator, i.e., the one closest to the Gribov horizon. Although such choice of gauge drives the ghost propagator towards the prediction of continuum calculations, we find that it actually overshoots the goal. With increasing computer time, we observe that Gribov copies with arbitrarily small eigenvalues can be found. For such a method to work, one would therefore need further restrictions on the gauge condition to isolate the physically relevant copies, since, for example, the Coulomb potential VC defined through the Faddeev-Popov operator becomes otherwise physically meaningless. Interestingly, the Coulomb potential alternatively defined through temporal link correlators is only marginally affected by the smallness of the eigenvalues.

  20. Detailed ocean current maps may lie over the horizon

    NASA Astrophysics Data System (ADS)

    Carlowicz, Michael

    In another case of military swords being turned into scientific plowshares, two American researchers have used radar systems once designed to detect Soviet planes during the Cold War to map open-ocean currents instead.In the name of science, Thomas Georges and Jack Harlan of NOAA's Environmental Technology Laboratory borrowed some time last summer on the U.S. Navy's over-the-horizon (OTH) radar systems in both Virginia and Texas. Training the radars on the waters off of the southern coast of Florida, the researchers gathered enough data to deduce the surface motion of two 70,000 km2 swatches of the Caribbean Sea and Gulf of Mexico. By bouncing 5-28 MHz radio waves off the ionosphere down to the sea surface and back, the researchers were able to derive the characteristics of the ocean surface from Bragg backscatter resonance.

  1. Acceleration of organic matter decomposition after the input of available substrate in subsoil horizons

    NASA Astrophysics Data System (ADS)

    Blagodatskaya, Evgenia; Zhuravleva, Anna; Blagodatsky, Sergey; Yakimov, Artem; Demkin, Vitaly; Kuzyakov, Yakov

    2010-05-01

    Input of available substrates to soil can alter microbial activity resulting in accelerated turnover of native soil organic matter (SOM), i.e. cause priming effects (PE). Following to Fountaine et al. (2007) we hypothesized that the stability of SOM in deep soil horizons is due to the lack of input of fresh organic substrates. We also hypothesized greater PE in mineral versus organic soil horizons. These hypotheses were checked by the comparison of priming effects induced by 14C-glucose in organic and mineral horizons of modern as well as of paleo-soils (podzol sandy soil Yamalo-Nenezky region, Tumen). The following variables were determined in 50-days incubation experiment: 1) dynamics of CO2 evolution; 2) 14CO2 originated from the added glucose; 3) microbial biomass C by substrate-induced respiration; 4) activities of extracellular enzymes (β-glucosidase, chitinase, cellobiogidrolase and xylanase) with fluorogenically labeled substrates. Maximal intensity of SOM mineralization as well as of enzyme activities was observed at 2 -7 days after glucose application. The absolute values of PE were 10 times greater in modern as compared with buried horizons of paleo-soils. However, the relative increase in carbon mineralization (as compared with control soil without glucose amendment) was greater in buried than in modern soils, especially in mineral soil horizons. In organic horizons the PE amounted for 20 and 50 % of untreated control in modern and in paleo-soils, respectively. In mineral horizons the PE amount (in % of control) reached 60 % for modern and 250 % for paleo-soils. We conclude that the input of fresh organic matter in paleo-soils as well as in deep soil horizons can induce greater PE as compared with topsoil layers. This conclusion was further confirmed by the increased activity of hydrolytic enzymes during PE in modern and in buried soils. Reference: Fontaine S, Barot S, Barre P, Bdioui N, Mary B, Rumpel C (2007) Stability of organic carbon in deep soil

  2. Building a Seismic Sequence Stratigraphy Model Using HorizonCubes: A Jurassic Case Study in the Arabian Basin

    NASA Astrophysics Data System (ADS)

    AlYousuf, T. Y.

    2012-12-01

    Understanding the regional stratigraphic framework of the Middle and Upper Jurassic (Late Callovian-Oxfordian - Early Kimmeridgian) formations in the Arabian Basin is extremely important for unlocking the area's hydrocarbon potential. With recent advances in computing power and interpretation software, seismic sequence stratigraphy has become an important tool in reservoir characterization, and for reducing exploration risk. This paper provides a workflow that can be used to model seismic horizons using a dip steering volume. The workflow consists of data conditioning to produce a dip steering volume to generate a volume of densely spaced, automatically tracked seismic horizons, a "HorizonCube". The horizons are derived from the dip and azimuth information stored in the dip steered seismic volume model. In the Wheeler domain, the seismic volume is recomputed and flattened accordingly to match the Wheeler transformed HorizonCube. Based on the HorizonCube model, it is possible to identify stratigraphic carbonate buildups and depositional sequences. Isolating the horizon cube into smaller packages shows the dynamic variation in the deposition of sediments through time and space during the Jurassic period, starting from the top of Minjur sandstone to the Arab D limestone. The geologist is also able to identify system tracts with stratigraphic surfaces and estimate a stratigraphic base level curve. The approach is extended to integrate with the well correlation panel for better confidence in picking well tops. Visualizing system tract-interpretations together with the HorizonCube and overlaying the seismic and Wheeler-transformed domains helps to identify depositional features of interest that may form stratigraphic traps.

  3. The formation of frangipane horizons and their influence on physical-chemical properties of soils from glass houses

    NASA Astrophysics Data System (ADS)

    Filipov, F.; Bulgariu, D.; Avarvarei, I.

    2009-04-01

    reduction of the accessibility of these for cultivated vegetables, and have important consequences on the productivity and on the quality of obtained products. Under these conditions, in the same time with the formation of frangipane horizons, the fast degradation of physical-mechanical and chemical properties of antrosols occurs. The conditions for the frangipane horizons formation are not yet elucidated. Ours experimental results indicate that the formation of frangipane horizons in soils from glass houses is first determined by the intensive technologies used for vegetables cultivation, by the application of a supra-dimensional irrigation system, the maintaining of high and relatively constants humidity state and temperatures (in comparison with un-protected soils). The nature of parental material has also, an important influence on the physical-chemical and mineralogical properties of frangipane horizons and these control the formation and spatial extension rates of these horizons. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51045/07).

  4. Photodynamic therapy in dermatology: history and horizons.

    PubMed

    Taub, Amy Forman

    2004-01-01

    Photodynamic therapy (PDT) uses a photosensitizer, light, and molecular oxygen to selectively kill cells. When localized in the target tissue, the photosensitizer is activated by light to produce oxygen intermediates that destroy target tissue cells. The easy access of skin to light-based therapy has led dermatologists to apply PDT to cutaneous disorders. In dermatology, PDT has been most successful in treating actinic keratoses, basal cell carcinoma, and Bowen's disease. The introduction of aminolevulinic acid, which does not make patients susceptible to phototoxicity for extended periods, has reduced morbidity associated with PDT. This has led to new interest in PDT not only for nonmelanoma skin cancer and premalignant lesions but also in the treatment of acne and as an adjuvant to photorejuvenation procedures. This review examines the historical roots of PDT and the research evaluating different light and laser sources as well as reports on new horizons for PDT in dermatology.

  5. 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.

  6. 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*).

  7. 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…

  8. Submesoscale Dispersion in the Vicinity of the Deepwater Horizon Spill

    DTIC Science & Technology

    2014-09-02

    ecosystems, society, and the economy as evidenced by the Deepwater Horizon oil spill in the Gulf of Mexico in 2010 and the Fukushima nuclear plant...evidenced by the Deepwater Horizon oil spill in the Gulf of Mexico in 2010 and the Fukushima nuclear plant incident in the Pacific Ocean in 2011. Accurate

  9. 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

  10. Near-horizon conformal symmetry and black hole entropy.

    PubMed

    Carlip, S

    2002-06-17

    Near an event horizon, the action of general relativity acquires a new asymptotic conformal symmetry. For two-dimensional dilaton gravity, this symmetry results in a chiral Virasoro algebra, and Cardy's formula for the density of states reproduces the Bekenstein-Hawking entropy. This lends support to the notion that black hole entropy is controlled universally by conformal symmetry near the horizon.

  11. 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…

  12. Comparing Three Jet Rates with and without Hadronic Rindler Horizon

    NASA Astrophysics Data System (ADS)

    Ghaffary, Tooraj

    2017-03-01

    Recently, some researchers, (Sepehri and Shoorvazi Chin. Phys. Lett. 30(2), 021301, [2013]), have considered the effect of Rindler horizon on three jet rate. This paper confirms their results and by comparing usual models with this new model for different energies, shows that regarding Rindler horizon gives us the results which more close to experimental data respect to usual models.

  13. 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.

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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.

  19. 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.

  20. Receding horizon control of nonlinear systems: A control Lyapunov function approach

    NASA Astrophysics Data System (ADS)

    Jadbabaie, Ali

    With the advent of faster and cheaper computers, optimization based control methodologies have become a viable candidate for control of nonlinear systems. Over the past twenty years, a group of such control schemes have, been successfully used in the process control industry where the processes are either intrinsically stable or have very large time constants. The purpose of this thesis is to provide a theoretical framework for synthesis of a class of optimization based control schemes, known as receding horizon control techniques for nonlinear systems such as unmanned aerial vehicles. It is well known that unconstrained infinite horizon optimal control may be used to construct a stabilizing controller for a nonlinear system. In this thesis, we show that similar stabilization results may be achieved using unconstrained finite horizon optimal control. The key idea is to approximate the tail of the infinite horizon cost-to-go using, as terminal cost, an appropriate control Lyapunov function (CLF). A CLF can be thought of as generalization of the concept of a Lyapunov function to systems with inputs. Roughly speaking, the terminal CLF should provide an (incremental) upper bound on the cost. In this fashion, important stability characteristics may be retained without the use of terminal constraints such as those employed by a number of other researchers. The absence of constraints allows a significant speedup in computation. Furthermore, it is shown that in order to guarantee stability, it suffices to satisfy an improvement property, thereby, relaxing the requirement, that truly optimal trajectories be found. We provide a complete analysis of the stability and region of attraction/operation properties of receding horizon control strategies that utilize finite horizon approximations in the proposed class. It is shown that the guaranteed region of operation contains that of the CLF controller and may be made as large as desired by increasing the optimization horizon

  1. 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.)

  2. 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.

  3. 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.

  4. 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.

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

    PubMed

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

    1983-07-08

    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.

  6. 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...

  7. Spacetimes foliated by nonexpanding and Killing horizons: Higher dimension

    NASA Astrophysics Data System (ADS)

    Lewandowski, Jerzy; Szereszewski, Adam; Waluk, Piotr

    2016-09-01

    The theory of nonexpanding horizons (NEHs) geometry and the theory of near-horizon geometries (NHGs) are two mathematical relativity frameworks generalizing the black hole theory. From the point of view of the NEHs theory, a NHG is just a very special case of a spacetime containing a NEH of many extra symmetries. It can be obtained as the Horowitz limit of a neighborhood of an arbitrary extremal Killing horizon. An unexpected relation between the two of them was discovered in the study of spacetimes foliated by a family of NEHs. The class of four-dimensional NHG solutions (either vacuum or coupled to a Maxwell field) was found as a family of examples of spacetimes admitting a NEH foliation. In the current paper, we systematically investigate geometries of the NEHs foliating a spacetime for arbitrary matter content and in arbitrary spacetime dimensions. We find that each horizon belonging to the foliation satisfies a condition that may be interpreted as an invitation for a transversal NEH to exist and to admit the structure of an extremal isolated horizon. Assuming the existence of a transversal extremal isolated horizon, we derive all the spacetime metrics satisfying the vacuum Einstein's equations. In this case, the NEHs become bifurcated Killing horizons.

  8. 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.

  9. Ground-based Observations of Io In Support of The New Horizons Flyby

    NASA Astrophysics Data System (ADS)

    Rathbun, Julie A.; Spencer, J. R.

    2007-10-01

    Io is the most volcanically active body in the solar system and has been observed from ground-based telescopes for more than two decades. The frequency of observations increases dramatically when spacecraft are observing Io in order to complement the data returned by the spacecraft. The New Horizons spacecraft flew by Jupiter on February 28th, 2007 and observed Io with visible (0.4-1.0 microns) and near-infrared (1.2-2.5 microns) instruments. We observed Io from the Infrared Telescope Facility in Hawaii in order to complement the data being taken by New Horizons. Our observations were at longer wavelengths than New Horizons with some overlap (2.2, 3.5, and 4.8 microns). We were also able to observe Io over a longer period of time (August 2006 through June 2007) to put the New Horizons data into a broader temporal context. During nine partial nights we observed Io in eclipse (to avoid reflected sunlight) and during Jupiter occultations (to isolate individual volcanoes). From these observations, we were able to observe active volcanoes on the Jupiter facing hemisphere and measure the brightness of the largest volcano, Loki. We found that Loki was very faint during this entire period, though temporal variations were seen at other volcanoes. During seven partial nights, we observed Io's sunlit disk at 3.5 microns at a variety of longitudes for good coverage of volcanic activity at all longitudes. We took a series of short exposures and added together those with the best seeing in order to improve the spatial resolution. During five of the observations, starting on January 18th 2007, the volcano Tvashtar was visible, showing that the major eruption detected by New Horizons was active for over a month before the flyby. We will deconvolve these images in order to determine the brightness of Tvashtar (at 3.5 microns) between mid-January and early March.

  10. Closed universes with black holes but no event horizons as a solution to the black hole information problem

    NASA Astrophysics Data System (ADS)

    Tipler, Frank J.; Graber, Jessica; McGinley, Matthew; Nichols-Barrer, Joshua; Staecker, Christopher

    2007-08-01

    We show that it is possible for the information paradox in black hole evaporation to be resolved classically. Using standard junction conditions, we attach the general closed spherically symmetric dust metric to a space-time satisfying all standard energy conditions but with a single point future c-boundary. The resulting Omega Point space-time, which has NO event horizons, nevertheless has black hole type trapped surfaces and hence black holes. However, since there are no event horizons, information eventually escapes from the black holes. We show that a scalar quintessence field with an appropriate exponential potential near the final singularity would give rise to an Omega Point final singularity.

  11. 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.

  12. 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.

  13. Polarimetric VLBI with the Event Horizon Telescope

    NASA Astrophysics Data System (ADS)

    Fish, Vincent L.; Doeleman, S.; Marrone, D. P.; Lu, R.; Wardle, J. F.; EHT Collaboration

    2013-01-01

    The Event Horizon Telescope is a collaboration to observe the innermost accretion and outflow regions around supermassive black holes with an array of millimeter-wavelength telescopes. EHT observations have detected emission on scales of tens of microarcseconds around the black holes in the center of the Milky Way and M87. Non-polarimetric measurements have successfully been used to identify and model the Schwarzschild-radius-scale emission around these sources as well as to identify previously unresolvable structures in more distant AGNs and blazars, but new polarimetric data can provide additional information on the magnetic field strength and geometry in the jet launch and collimation region. Recent full-polarization VLBI observations with the EHT have detected polarized 1.3 mm emission arising on extremely small angular scales in a variety of extragalactic sources. We report on the results of these detections and detail the prospects for precision polarimetry thanks to the substantial EHT sensitivity improvements that will be realized over the next few years.

  14. Use of the Internet in Scanning the Horizon for New and Emerging Health Technologies: A Survey of Agencies Involved in Horizon Scanning

    PubMed Central

    Vondeling, Hindrik; Eskildsen, Drea; Simpson, Sue

    2003-01-01

    Background A number of countries worldwide have structured horizon scanning systems which provide timely information on the impact of new health technologies to decision makers in health care. In general, the agencies that are responsible for horizon scanning have limited resources in terms of budget and staff. In contrast, the number of new and emerging health technologies, i.e. pharmaceuticals, medical devices, and medical and surgical procedures, is growing rapidly. This requires the Horizon Scanning Systems (HSSs) to devise efficient procedures for identification of new health technologies. The role of the Internet for this purpose has as yet not been documented. Objective To describe and analyse how the Internet is used by horizon scanning systems to systematically identify new health technologies. Methods A questionnaire was developed and distributed among 10 agencies known to work within this specific area. The questionnaire specifically focussed on type of sites scanned, frequency of scanning, and importance of a site for the identification of a new health technology. Results A 100% response rate was obtained. Seven out of 10 agencies used the Internet to systematically identify new health technologies, of which 6 provided complete information. A total of 110 web sites were scanned by these 6 agencies. The number of sites scanned per agency ranged from 11 to 27. Most sites were scanned weekly (41%) or monthly (33%). Thirty-one percent (31%) of the total number of sites was considered as highly important. The agencies spent at least 2 hours a week and at most 8 hours per week scanning the Internet. Although each agency's remit differed somewhat in scope, on average the same types of sites were scanned. These include sites from regulatory agencies, sites with information on new drugs or new devices, and sites with news from newswires. However, within these types there was not much correlation between the individual sites that agencies judged important to scan

  15. Opaline sediments of the southeastern coastal plain and horizon a: biogenic origin.

    PubMed

    Weaver, F M; Wise, S W

    1974-05-24

    Scanning electron microscope techniques show that Eocene opaline claystones (fuller's earth and buhrstone) of the Atlantic and Gulf Coastal Plain, deposits long considered volcanic in origin, are actually highly altered diatomites formed as transgressive facies in normal marine continental shelf environmnents. These findings are in agreement with a biogenic origin for time-equivalent horizon A and A deep-sea cherts of the North Atlantic and Caribbean.

  16. HVPE InGaN for LEDs- State of the Art and Horizons

    DTIC Science & Technology

    2012-01-19

    The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing...Washington Headquarters Services, Directorate for Information Operations and Reports , 1215 Jefferson Davis Highway, Suite 1204, Arlington VA, 22202-4302... REPORT "HVPE InGaN for LEDs- State of the art and horizons." 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: We grew unintentionally doped n-type InGaN

  17. Beyond the event horizon or altogether without it?

    NASA Astrophysics Data System (ADS)

    Lobanov, Andrei

    2017-03-01

    Millimetre-wavelength interferometry and gravitational-wave detectors currently provide the most stringent tests for the existence of cosmic black holes. Complementary measurements of magnetic fields near their event horizon would be decisive.

  18. 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 ...

  19. Hints of quantum gravity from the horizon fluid

    NASA Astrophysics Data System (ADS)

    Cropp, Bethan; Bhattacharya, Swastik; Shankaranarayanan, S.

    2017-01-01

    For many years, researchers have tried to glean hints about quantum gravity from black hole thermodynamics. However, black hole thermodynamics suffers from the problem of universality—at leading order, several approaches with different microscopic degrees of freedom lead to Bekenstein-Hawking entropy. We attempt to bypass this issue by using a minimal statistical mechanical model for the horizon fluid based on the Damour-Navier-Stokes (DNS) equation. For stationary asymptotically flat black hole spacetimes in general relativity, we show explicitly that, at equilibrium, the entropy of the horizon fluid is the Bekenstein-Hawking entropy. Further, we show that, for the bulk viscosity of the fluctuations of the horizon fluid to be identical to Damour, a confinement scale exists for these fluctuations, implying quantization of the horizon area. The implications and possible mechanisms from the fluid point of view are discussed.

  20. Deepwater Horizon – BP Gulf of Mexico Oil Spill

    EPA Pesticide Factsheets

    This webpage provides information and materials on EPA’s enforcement response to the Deepwater Horizon Oil Spill, including settlements with some of the defendants, as well as links to other related websites for additional information.

  1. Einstein–Weyl spaces and near-horizon geometry

    NASA Astrophysics Data System (ADS)

    Dunajski, Maciej; Gutowski, Jan; Sabra, Wafic

    2017-02-01

    We show that a class of solutions of minimal supergravity in five dimensions is given by lifts of three-dimensional Einstein–Weyl structures of hyper-CR type. We characterise this class as most general near-horizon limits of supersymmetric solutions to the five-dimensional theory. In particular we deduce that a compact spatial section of a horizon can only be a Berger sphere, a product metric on {{S}1}× {{S}2} or a flat three-torus. We then consider the problem of reconstructing all supersymmetric solutions from a given near-horizon geometry. By exploiting the ellipticity of the linearised field equations we demonstrate that the moduli space of transverse infinitesimal deformations of a near-horizon geometry is finite-dimensional.

  2. Horizon Based Orientation Estimation for Planetary Surface Navigation

    NASA Technical Reports Server (NTRS)

    Bouyssounouse, X.; Nefian, A. V.; Deans, M.; Thomas, A.; Edwards, L.; Fong, T.

    2016-01-01

    Planetary rovers navigate in extreme environments for which a Global Positioning System (GPS) is unavailable, maps are restricted to relatively low resolution provided by orbital imagery, and compass information is often lacking due to weak or not existent magnetic fields. However, an accurate rover localization is particularly important to achieve the mission success by reaching the science targets, avoiding negative obstacles visible only in orbital maps, and maintaining good communication connections with ground. This paper describes a horizon solution for precise rover orientation estimation. The detected horizon in imagery provided by the on board navigation cameras is matched with the horizon rendered over the existing terrain model. The set of rotation parameters (roll, pitch yaw) that minimize the cost function between the two horizon curves corresponds to the rover estimated pose.

  3. 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.

  4. 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.

  5. "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.

  6. 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.

  7. Moving horizon observer with regularisation for detectable systems without persistence of excitation

    NASA Astrophysics Data System (ADS)

    Sui, Dan; Johansen, Tor A.

    2011-06-01

    A constrained moving horizon observer is developed for nonlinear discrete-time systems. The algorithm is proved to converge exponentially under a detectability assumption with the data being exciting at all times. However, in many practical estimation problems, such as combined state and parameter estimation, the data may not be exciting for every period of time. The algorithm therefore has regularisation mechanisms to ensure robustness and graceful degradation of performance in cases when the data are not exciting. This includes the use of a priori estimates in the moving horizon cost function, and the use of thresholded singular value decomposition to avoid ill-conditioned or ill-posed inversion of the associated nonlinear algebraic equations that define the moving horizon cost function. The latter regularisation relies on monitoring of the rank of an estimate of a Hessian-like matrix and conditions for uniform exponential convergence are given. The method is in particular useful with augmented state space models corresponding to mixed state and parameter estimation problems, or dynamics that are not asymptotically stable, as illustrated with two simulation examples.

  8. Supertranslations and Superrotations at the Black Hole Horizon.

    PubMed

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

    2016-03-04

    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.

  9. Evaporating dynamical horizon with the Hawking effect in Vaidya spacetime

    SciTech Connect

    Sawayama, Shintaro

    2006-03-15

    We consider how the mass of the black hole decreases due to the Hawking radiation in the Vaidya spacetime, using the concept of the dynamical horizon equation, proposed by Ashtekar and Krishnan. Using the formula for the change of the dynamical horizon, we derive an equation for the mass incorporating the Hawking radiation. It is shown that the final state is the Minkowski spacetime in our particular model.

  10. Waste Sampling Data for BP Spill/Deepwater Horizon

    EPA Pesticide Factsheets

    The Deepwater Horizon oil spill (also referred to as the BP oil spill) began on 20 April 2010 in the Gulf of Mexico on the BP-operated Macondo Prospect. Following the explosion and sinking of the Deepwater Horizon oil rig, a sea-floor oil gusher flowed for 87 days, until it was capped on 15 July 2010.In response to the BP oil spill, EPA sampled air, water, sediment, and waste generated by the cleanup operations.

  11. Air Sampling Data for BP Spill/Deepwater Horizon

    EPA Pesticide Factsheets

    The Deepwater Horizon oil spill (also referred to as the BP oil spill) began on 20 April 2010 in the Gulf of Mexico on the BP-operated Macondo Prospect. Following the explosion and sinking of the Deepwater Horizon oil rig, a sea-floor oil gusher flowed for 87 days, until it was capped on 15 July 2010.In response to the BP oil spill, EPA sampled air, water, sediment, and waste generated by the cleanup operations.

  12. Air Monitoring Data for BP Spill/Deepwater Horizon

    EPA Pesticide Factsheets

    The Deepwater Horizon oil spill (also referred to as the BP oil spill) began on 20 April 2010 in the Gulf of Mexico on the BP-operated Macondo Prospect. Following the explosion and sinking of the Deepwater Horizon oil rig, a sea-floor oil gusher flowed for 87 days, until it was capped on 15 July 2010.In response to the BP oil spill, EPA sampled air, water, sediment, and waste generated by the cleanup operations.

  13. Surface Water Sampling Data for BP Spill/Deepwater Horizon

    EPA Pesticide Factsheets

    The Deepwater Horizon oil spill (also referred to as the BP oil spill) began on 20 April 2010 in the Gulf of Mexico on the BP-operated Macondo Prospect. Following the explosion and sinking of the Deepwater Horizon oil rig, a sea-floor oil gusher flowed for 87 days, until it was capped on 15 July 2010.In response to the BP oil spill, EPA sampled air, water, sediment, and waste generated by the cleanup operations.

  14. Sediment Sampling Data for BP Spill/Deepwater Horizon

    EPA Pesticide Factsheets

    The Deepwater Horizon oil spill (also referred to as the BP oil spill) began on 20 April 2010 in the Gulf of Mexico on the BP-operated Macondo Prospect. Following the explosion and sinking of the Deepwater Horizon oil rig, a sea-floor oil gusher flowed for 87 days, until it was capped on 15 July 2010.In response to the BP oil spill, EPA sampled air, water, sediment, and waste generated by the cleanup operations.

  15. Water Sampling Data for BP Spill/Deepwater Horizon

    EPA Pesticide Factsheets

    The Deepwater Horizon oil spill (also referred to as the BP oil spill) began on 20 April 2010 in the Gulf of Mexico on the BP-operated Macondo Prospect. Following the explosion and sinking of the Deepwater Horizon oil rig, a sea-floor oil gusher flowed for 87 days, until it was capped on 15 July 2010.In response to the BP oil spill, EPA sampled air, water, sediment, and waste generated by the cleanup operations.

  16. A horizon scan of global conservation issues for 2010.

    PubMed

    Sutherland, William J; Clout, Mick; Côté, Isabelle M; Daszak, Peter; Depledge, Michael H; Fellman, Liz; Fleishman, Erica; Garthwaite, Rachel; Gibbons, David W; De Lurio, Jennifer; Impey, Andrew J; Lickorish, Fiona; Lindenmayer, David; Madgwick, Jane; Margerison, Ceri; Maynard, Trevor; Peck, Lloyd S; Pretty, Jules; Prior, Stephanie; Redford, Kent H; Scharlemann, Jörn P W; Spalding, Mark; Watkinson, Andrew R

    2010-01-01

    Horizon scanning identifies emerging issues in a given field sufficiently early to conduct research to inform policy and practice. Our group of horizon scanners, including academics and researchers, convened to identify fifteen nascent issues that could affect the conservation of biological diversity. These include the impacts of and potential human responses to climate change, novel biological and digital technologies, novel pollutants and invasive species. We expect to repeat this process and collation annually.

  17. 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.

  18. 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.

  19. Constrained field theories on spherically symmetric spacetimes with horizons

    NASA Astrophysics Data System (ADS)

    Fernandes, Karan; Lahiri, Amitabha; Ghosh, Suman

    2017-02-01

    We apply the Dirac-Bergmann algorithm for the analysis of constraints to gauge theories defined on spherically symmetric black hole backgrounds. We find that the constraints for a given theory are modified on such spacetimes through the presence of additional contributions from the horizon. As a concrete example, we consider the Maxwell field on a black hole background, and determine the role of the horizon contributions on the dynamics of the theory.

  20. 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.

  1. Black hole entropy from conformal symmetry on the horizon

    NASA Astrophysics Data System (ADS)

    Carlip, Steven

    2017-01-01

    The idea that black hole entropy might be governed by a conformal symmetry is an old one, but until now most efforts have focused on either asymptotic symmetries or symmetries on a ``stretched horizon. For two-dimensional dilaton gravity, I show the existence of a well-behaved conformal symmetry that is on the horizon, with a central charge that correctly determines the black hole entropy. Supported by Department of Energy grant DE-FG02-91ER40674.

  2. Reflection and transmission at the apparent horizon during gravitational collapse

    SciTech Connect

    Vaz, Cenalo; Wijewardhana, L. C. R.

    2010-10-15

    We examine the wave functionals describing the collapse of a self-gravitating dustball in an exact quantization of the gravity-dust system. We show that ingoing (collapsing) dust shell modes outside the apparent horizon must necessarily be accompanied by outgoing modes inside the apparent horizon, whose amplitude is suppressed by the square root of the Boltzmann factor at the Hawking temperature. Likewise, ingoing modes in the interior must be accompanied by outgoing modes in the exterior, again with an amplitude suppressed by the same factor. A suitable superposition of the two solutions is necessary to conserve the dust probability flux across the apparent horizon; thus, each region contains both ingoing and outgoing dust modes. If one restricts oneself to considering only the modes outside the apparent horizon then one should think of the apparent horizon as a partial reflector, the probability for a shell to reflect being given by the Boltzmann factor at the Hawking temperature determined by the mass contained within it. However, if one considers the entire wave function, the outgoing wave in the exterior is seen to be the transmission through the horizon of the interior outgoing wave that accompanies the collapsing shells. This transmission could allow information from the interior to be transferred to the exterior.

  3. Null infinity and extremal horizons in AdS-CFT

    NASA Astrophysics Data System (ADS)

    Hickling, Andrew; Lucietti, James; Wiseman, Toby

    2015-02-01

    We consider AdS gravity duals to CFT on background spacetimes with a null infinity. Null infinity on the conformal boundary may extend to an extremal horizon in the bulk. For example it does so for Poincaré-AdS, although does not for planar Schwarzschild-AdS. If null infinity does extend into an extremal horizon in the bulk, we show that the bulk near-horizon geometry is determined by the geometry of the boundary null infinity. Hence the ‘infra-red’ geometry of the bulk is fixed by the large scale behaviour of the CFT spacetime. In addition the boundary stress tensor must have a particular decay at null infinity. As an application, we argue that for CFT on asymptotically flat backgrounds, any static bulk dual containing an extremal horizon extending from the boundary null infinity, must have the near-horizon geometry of Poincaré-AdS. We also discuss a class of boundary null infinity that cannot extend to a bulk extremal horizon, although we give evidence that they can extend to an analogous null surface in the bulk which possesses an associated scale-invariant ‘near-geometry’.

  4. Rotating Killing horizons in generic F( R) gravity theories

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Sourav

    2016-10-01

    We discuss various properties of rotating Killing horizons in generic F( R) theories of gravity in dimension four for spacetimes endowed with two commuting Killing vector fields. Assuming there is no curvature singularity anywhere on or outside the horizon, we construct a suitable (3+1)-foliation. We show that similar to Einstein's gravity, we must have T_{ab}k^ak^b=0 on the Killing horizon, where k^a is a null geodesic tangent to the horizon. For axisymmetric spacetimes, the effective gravitational coupling ˜ F'^{-1}(R) should usually depend upon the polar coordinate and hence need not necessarily be a constant on the Killing horizon. We prove that the surface gravity of such a Killing horizon must be a constant, irrespective of whether F'(R) is a constant there or not. We next apply these results to investigate some further basic features. In particular, we show that any hairy solution for the real massive vector field in such theories is clearly ruled out, as long as the potential of the scalar field generated in the corresponding Einstein's frame is a positive definite quantity.

  5. Interferometric direction finding of over-horizon VHF transmitter signals and natural VHF radio emissions possibly associated with earthquakes

    NASA Astrophysics Data System (ADS)

    Yasuda, Y.; Ida, Y.; Goto, T.; Hayakawa, M.

    2009-04-01

    The over-horizon (out-of-sight) VHF transmitter signals are found to be received before an earthquake, and also natural VHF noises are known to be detected prior to an earthquake. In order to have a better understanding of these over-horizon VHF signals and noises, an interferometric direction-finding system has been, for the first time, introduced, and some preliminary observational results have been presented here. With FM Sendai as a target VHF transmitter (at 77.1 MHz), we have carried out the observation at Chofu (Tokyo). We can receive occasionally the over-horizon VHF transmission signals in possible association with earthquakes. We have analyzed a few earthquakes since the commencement of our observation, including a large one named the Niigata Chuetsu-oki earthquake. The azimuth distribution by means of the interferometer has enabled us to correlate any burst in the temporal evolution of electric field intensity to a certain earthquake. The over-horizon VHF transmitter signals are always well above the background noise, whose azimuth is found to be relatively close to the direction of Sendai (relatively away from the epicentral direction). Then, the VHF radio noises are always simultaneously detected as an enhancement of background noise, with their azimuths being relatively close to the epicenter of the quake. The mechanisms of seismoatmospheric perturbations as seen from the over-horizon VHF signal, as well as the natural VHF noise, are discussed.

  6. Bank erosion history of a mountain stream determined by means of anatomical changes in exposed tree roots over the last 100 years (Bílá Opava River — Czech Republic)

    NASA Astrophysics Data System (ADS)

    Malik, Ireneusz; Matyja, Marcin

    2008-06-01

    The date of exposure of spruce roots as a result of bank erosion was investigated on the Bílá Opava River in the northeastern Czech Republic. Following the exposure of roots, wood cells in the tree rings divide into early wood and late wood. Root cells within the tree rings also become smaller and more numerous. These processes permit dating of the erosion episodes in which roots were exposed. Sixty root samples were taken from seven sampling sites selected on two riverbed reaches. The results of root exposure dating were compared to historical data on hydrological flooding. Using the root exposure dating method, several erosion episodes were recorded for the last 100 years. The greatest bank erosion was recorded as consequence of an extraordinary flood in July 1997. In the upper, rocky part of the valley studied, bank erosion often took place during large floods that occurred in the early 20th century. In the lower, alluvial part of the valley, erosion in the exposed roots was recorded only in 1973 and has been intensive ever since. It is suggested that banks in the lower part are more frequently undercut, which leads to the falling of trees within whose roots older erosion episodes were recorded. Locally, bank erosion is often intensified by the position of 1- to 2-m boulders in the riverbed, which direct water into the parts of the banks where erosion occurs. Selective bank erosion could be intensified by debris dams and hillslope material supply to the riverbed.

  7. A Dynamic Scheduling Method of Earth-Observing Satellites by Employing Rolling Horizon Strategy

    PubMed Central

    Dishan, Qiu; Chuan, He; Jin, Liu; Manhao, Ma

    2013-01-01

    Focused on the dynamic scheduling problem for earth-observing satellites (EOS), an integer programming model is constructed after analyzing the main constraints. The rolling horizon (RH) strategy is proposed according to the independent arriving time and deadline of the imaging tasks. This strategy is designed with a mixed triggering mode composed of periodical triggering and event triggering, and the scheduling horizon is decomposed into a series of static scheduling intervals. By optimizing the scheduling schemes in each interval, the dynamic scheduling of EOS is realized. We also propose three dynamic scheduling algorithms by the combination of the RH strategy and various heuristic algorithms. Finally, the scheduling results of different algorithms are compared and the presented methods in this paper are demonstrated to be efficient by extensive experiments. PMID:23690742

  8. A dynamic scheduling method of Earth-observing satellites by employing rolling horizon strategy.

    PubMed

    Dishan, Qiu; Chuan, He; Jin, Liu; Manhao, Ma

    2013-01-01

    Focused on the dynamic scheduling problem for earth-observing satellites (EOS), an integer programming model is constructed after analyzing the main constraints. The rolling horizon (RH) strategy is proposed according to the independent arriving time and deadline of the imaging tasks. This strategy is designed with a mixed triggering mode composed of periodical triggering and event triggering, and the scheduling horizon is decomposed into a series of static scheduling intervals. By optimizing the scheduling schemes in each interval, the dynamic scheduling of EOS is realized. We also propose three dynamic scheduling algorithms by the combination of the RH strategy and various heuristic algorithms. Finally, the scheduling results of different algorithms are compared and the presented methods in this paper are demonstrated to be efficient by extensive experiments.

  9. 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.

  10. A laboratory analogue of the event horizon using slow light in an atomic medium.

    PubMed

    Leonhardt, Ulf

    2002-01-24

    Singularities underlie many optical phenomena. The rainbow, for example, involves a particular type of singularity-a ray catastrophe-in which light rays become infinitely intense. In practice, the wave nature of light resolves these infinities, producing interference patterns. At the event horizon of a black hole, time stands still and waves oscillate with infinitely small wavelengths. However, the quantum nature of light results in evasion of the catastrophe and the emission of Hawking radiation. Here I report a theoretical laboratory analogue of an event horizon: a parabolic profile of the group velocity of light brought to a standstill in an atomic medium can cause a wave singularity similar to that associated with black holes. In turn, the quantum vacuum is forced to create photon pairs with a characteristic spectrum, a phenomenon related to Hawking radiation. The idea may initiate a theory of 'quantum' catastrophes, extending classical catastrophe theory.

  11. Petroleum hydrocarbon persistence following the Deepwater Horizon oil spill as a function of shoreline energy.

    PubMed

    Evans, Meredith; Liu, Jiqing; Bacosa, Hernando; Rosenheim, Brad E; Liu, Zhanfei

    2017-02-15

    An important aspect of oil spill science is understanding how the compounds within spilled oil, especially toxic components, change with weathering. In this study we follow the evolution of petroleum hydrocarbons, including n-alkanes, polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs, on a Louisiana beach and salt marsh for three years following the Deepwater Horizon spill. Relative to source oil, we report overall depletion of low molecular weight n-alkanes and PAHs in all locations with time. The magnitude of depletion, however, depends on the sampling location, whereby sites with highest wave energy have highest compound depletion. Oiled sediment from an enclosed bay shows high enrichment of high molecular weight PAHs relative to 17α(H),21β(H)-hopane, suggesting the contribution from sources other than the Deepwater Horizon spill, such as fossil fuel burning. This insight into hydrocarbon persistence as a function of hydrography and hydrocarbon source can inform policy and response for future spills.

  12. 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

  13. 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.

  14. Genesis of petroduric and petrocalcic horizons in Latinamerica volcanic soils

    NASA Astrophysics Data System (ADS)

    Quantin, Paul

    2010-05-01

    Introduction. In Latinamerica, from Mexico to Chile, there are indurated volcanic soils horizons, named 'tepetate' in Mexico or cangahua in the Andes Mountains. Apart from original volcanic tuffs, these horizons were produced by pedogenesis: either through a former weathering of volcanic ash layers into fragic and later to petrocalcic horizons; or after a former soil formation through a second process of transformation from clayey volcanic soils to silicified petroduric horizons. This oral presentation will briefly deal with the formation of petroduric horizons in Mexico and petrocalcic horizon in Ecuador. Petroduric horizon genesis in Mexico. A soil climato-toposequence, near to Veracruz (Rossignol & Quantin, 1997), shows downwards an evolution from a ferralic Nitisol to a petroduric Durisol. A Durisol profile comports these successive horizons: at the top A and Eg, then columnar Btg-sim, laminar Bt-sim , prismatic Bsim, plinthite Cg, over andesite lava flow. Among its main features are especially recorded: clay mineralogy, microscopy and HRTEM. These data show: an increase in cristobalite at the expenses of 0.7 nm halloysite in Egsiltans, laminar Bt-sim, around or inside the columns or prisms of Btg-sim and Bsimhorizons. HRTEM (Elsass & al 2000) on ultra thin sections reveals an 'epigenesis' of clay sheets by amorphous silica, to form successively A-opal, Ct-opal and microcrystalline cristobalite. From these data and some groundwater chemical analyses, a scenario of duripan formation from a past clayey Nitisol is inferred: clay eluviation-illuviation process? alternate redoximorphy? clay degradation, Al leaching and Si accumulation, to form successively A-opal, Ct-opal and cristobalite. Petrocalcic horizon genesis in Ecuador. A soil climato-toposequence on pyroclastic flows, near to Bolivar in Ecuador (Quantin & Zebrowski, 1997), shows downwards the evolution from fragic-eutric-vitric Cambisols to petrocalcic-vitric Phaeozems, at the piedmont under semi

  15. Dark energy in thermal equilibrium with the cosmological horizon?

    NASA Astrophysics Data System (ADS)

    Poitras, Vincent

    2014-03-01

    According to a generalization of black hole thermodynamics to a cosmological framework, it is possible to define a temperature for the cosmological horizon. The hypothesis of thermal equilibrium between the dark energy and the horizon has been considered by many authors. We find the restrictions imposed by this hypothesis on the energy transfer rate (Qi) between the cosmological fluids, assuming that the temperature of the horizon has the form T =b/2πR, where R is the radius of the horizon. We more specifically consider two types of dark energy: Chaplygin gas (CG) and dark energy with a constant equation of state parameter (wDE). In each case, we show that for a given radius R, there is a unique term Qde that is consistent with thermal equilibrium. We also consider the situation where, in addition to dark energy, other fluids (cold matter, radiation) are in thermal equilibrium with the horizon. We find that the interaction terms required for this will generally violate energy conservation (∑iQi=0).

  16. Universality of P - V criticality in horizon thermodynamics

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

    We study P - V criticality of black holes in Lovelock gravities in the context of horizon thermodynamics. The corresponding first law of horizon thermodynamics emerges as one of the Einstein-Lovelock equations and assumes the universal (independent of matter content) form δ E = T δ S - P δ V , where P is identified with the total pressure of all matter in the spacetime (including a cosmological constant Λ if present). We compare this approach to recent advances in extended phase space thermodynamics of asymptotically AdS black holes where the `standard' first law of black hole thermodynamics is extended to include a pressure-volume term, where the pressure is entirely due to the (variable) cosmological constant. We show that both approaches are quite different in interpretation. Provided there is sufficient non-linearity in the gravitational sector, we find that horizon thermodynamics admits the same interesting black hole phase behaviour seen in the extended case, such as a Hawking-Page transition, Van der Waals like behaviour, and the presence of a triple point. We also formulate the Smarr formula in horizon thermodynamics and discuss the interpretation of the quantity E appearing in the horizon first law.

  17. New Horizons: Overview of Results From and Plans After the Exploration of The Pluto System

    NASA Astrophysics Data System (ADS)

    Stern, S. Alan; Weaver, Harold A.; Olkin, Catherine B.; Young, Leslie; Ennico, Kimberly; Moore, Jeffrey M.; Spencer, John R.; McKinnon, William B.; Grundy, Will; Gladstone, Randy; Cruikshank, Dale P.; Bagenal, Fran; Summers, Michael; New Horizons Team

    2016-10-01

    Essentially all of the data from the New Horizons Pluto system flyby that culminated in July 2015 is expected to be on Earth by the time of this meeting. As of mid-June 2016, about 75% of those data have been received. All near encounter observations downlinked so far have been examined and were determined to be successful; engineering data from the remaining observations yet to be downlinked indicates they were all successful as well. The first Planetary Data System (PDS) Pluto system delivery has been made; a second PDS delivery is planned for October, with still more deliveries leading to complete and final dataset archiving by late 2017. Numerous scientific results have been obtained, and over 40 scientific papers have been published or submitted by mid-June 2016. This invited review will examine the most interesting geological, compositional, atmospheric, and plasma results obtained about Pluto, Charon and their small moons, and will go on to explore the implications of key results for understanding dwarf planets in general and the origin of the Pluto system in specific. New Horizons is healthy and operating nominally. If its Kuiper Belt Extended Mission is approved, numerous KBO and heliospheric observations are planned for 2016 and beyond, including the very close flyby of the cold, classical KBO 2014 MU69 on 1 January 2019. We summarize these and other plans for New Horizons.

  18. 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

  19. 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.

  20. Rapid mineral differentiation among horizons of a meadow soil

    NASA Astrophysics Data System (ADS)

    Szalai, Zoltán; Ringer, Marianna; Kiss, Klaudia; Horváth Szabó, Kata; Németh, Tibor; Sipos, Péter; Madarász, Balázs; Jakab, Gergely

    2015-04-01

    Soil development under hydromorphic conditions may results intense mineral transformation and rapid vertical differentiation in the profile. Original papers refer more than hundreds of years for this kinds of mineral transformations. We suppose that this process could be more rapid. Present paper focuses on the profile development of a sandy meadow soil (calcic, gleyic Phaeozem ferric, arenic) from the soil mineralogical viewpoint. The main aim was to explore the degree of mineral phase alteration via soil formation during a half-century under hydromorphic conditions. The studied soil is located in a swampy area (near to Ceglédbercel, Hungary). The parent material deposited during an extremely heavy flood event in 1963. The reference (parent) material can be found near to the study site. We combined routine field tests (carbonate content, dipididil test) with laboratory measurements (selective extractions for the determination of amorphous and crystalline Fe, and Mn content; X-ray phase analysis; X-ray fluorescence spectroscopy; particle sizing by laser diffraction; NDIR and FT-IR and DRS spectrometry), whereas Eh and pH measured by field monitoring station. The most intense mineralogical transformations developed in the zone of the heaviest redox oscillation. Results show that well developed horizons have emerged during fifty years in the studied soil. This time was enough for bivalent and trivalent iron mineral crystallisation and smectite formation in this zone. The high proportion of amorphous and colloidal phases refers to very intensive recent processes. Soil formation under hydromorphic conditions proceeds at higher speeds contrariwise to the century time scale reported in sources (discussing non-waterlogged cases). Support of the Hungarian Research Fund OTKA under contracts K100180 (for Z. Szalai) and K100181 (for T Németh) are gratefully acknowledged.

  1. New Horizons at Pluto: Asking the right questions

    NASA Astrophysics Data System (ADS)

    Young, Leslie; Stern, S. Alan; Olkin, Catherine B.; Spencer, John R.; Cheng, Andrew F.; Weaver, Harold A.; Ennico, Kimberly; Moore, Jeffrey M.; Grundy, William M.; Bagenal, Fran; Gladstone, Randy; Lunine, Jonathan I.; New Horizons Science Team

    2016-10-01

    In the 1980's and 1990's, breakthroughs about Pluto and the outer solar system laid the groundwork for the Outer Planets Science Working Group (1992), the Pluto Kuiper Express mission Science Definition Team (1996), and the Announcement of Opportunity for the Pluto Kuiper-Belt mission in 2001. These included specific science goals that molded the mission design, instrument selection, and observing sequence. These goals held up amazingly well over the decades. This historical review of New Horizons will explain how ground-based and theoretical work prepared us for a successful investigation of Pluto, and speculate on some of the new questions raised by the New Horizons flyby of the Pluto system.This work was supported by NASA's New Horizons project.

  2. Optimal control of circular cylinder wakes using long control horizons

    NASA Astrophysics Data System (ADS)

    Flinois, Thibault L. B.; Colonius, Tim

    2015-08-01

    The classical problem of suppressing vortex shedding in the wake of a circular cylinder by using body rotation is revisited in an adjoint-based optimal control framework. The cylinder's unsteady and fully unconstrained rotation rate is optimized at Reynolds numbers between 75 and 200 and over horizons that are longer than in previous studies, where they are typically of the order of a vortex shedding period or shorter. In the best configuration, the drag is reduced by 19%, the vortex shedding is effectively suppressed, and this low drag state is maintained with minimal cylinder rotation after transients. Unlike open-loop control, the optimal control is shown to maintain a specific phase relationship between the actuation and the shedding in order to stabilize the wake. A comparison is also given between the performance of optimizations for different Reynolds numbers, cost functions, and horizon lengths. It is shown that the long horizons used are necessary in order to stabilize the vortex shedding efficiently.

  3. 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.

  4. Universality in chaos of particle motion near black hole horizon

    NASA Astrophysics Data System (ADS)

    Hashimoto, Koji; Tanahashi, Norihiro

    2017-01-01

    The motion of a particle near a horizon of a spherically symmetric static black hole is shown to possess a universal Lyapunov exponent of chaos bounded by its surface gravity. To probe the horizon, we introduce an electromagnetic or scalar force to the particle so that it does not fall into the horizon. There appears an unstable maximum of the total potential where the evaluated maximal Lyapunov exponent is found to be to the surface gravity of the black hole. This value is independent of the external forces, the particle mass and background geometry, and in this sense this Lyapunov exponent is universal. Unless there are other sources of chaos, the Lyapunov exponent is subject to an inequality λ ≤2 π TBH/ℏ, which is identical to the bound recently discovered by Maldacena, Shenker, and Stanford.

  5. 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.

  6. Finite-horizon optimal investment with transaction costs: A parabolic double obstacle problem

    NASA Astrophysics Data System (ADS)

    Dai, Min; Yi, Fahuai

    This paper concerns optimal investment problem of a CRRA investor who faces proportional transaction costs and finite time horizon. From the angle of stochastic control, it is a singular control problem, whose value function is governed by a time-dependent HJB equation with gradient constraints. We reveal that the problem is equivalent to a parabolic double obstacle problem involving two free boundaries that correspond to the optimal buying and selling policies. This enables us to make use of the well-developed theory of obstacle problem to attack the problem. The C regularity of the value function is proven and the behaviors of the free boundaries are completely characterized.

  7. New Horizons: Gas and Plasma in the Pluto System

    NASA Astrophysics Data System (ADS)

    Young, Leslie; Gladstone, Randy; Summers, Michael; Bagenal, Fran; Stern, S. Alan; Weaver, Harold A.; Olkin, Catherine B.; Ennico, Kimberly; Moore, Jeffrey M.; Grundy, William M.; New Horizons Atmospheres Science Theme Team, New Horizons Particles and Plasma Science Theme Team

    2016-10-01

    NASA's New Horizons mission gave us information about gas and plasma in the Pluto system from Pluto's surface up to a distance of ~200,000 km beyond Pluto. This review will give an overview of our current theories and observations of the near-surface atmospheric structure; the properties, production and settling of Pluto's ubiquitous haze; the minor atmospheric species and atmospheric chemistry; the energetics and high-altitude thermal structure; the escape rate and the pickup of methane ions; the effect of methane impacting Charon; and Pluto's heavy-ion tail. Details are given in other presentations at this conference.This work was supported by NASA's New Horizons project.

  8. 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.

  9. Spores, pollen, and microplankton from the horizon Beta outcrop.

    PubMed

    Habib, D

    1968-12-27

    Palynology was used for dating a pre-Pleistocene deep-sea organic lutite layer situated stratigraphically near seismic horizon beta, below horizon A. The spores and pollen are closely identified, quantitatively, with nonmarine and marine Middle Cretaceous assemblages (Albian-Cenomanian) on the continents, an age designation that is confirmed by the occurrence of dinoflagellate cysts, acritarchs, foraminifers, and coccoliths in the investigated cores. The abundance of these well-preserved, land-derived assemblages in an area far removed from a source suggests some tectonic displacement since their deposition.

  10. Foliation dependence of black hole apparent horizons in spherical symmetry

    NASA Astrophysics Data System (ADS)

    Faraoni, Valerio; Ellis, George F. R.; Firouzjaee, Javad T.; Helou, Alexis; Musco, Ilia

    2017-01-01

    Numerical studies of gravitational collapse to black holes make use of apparent horizons, which are intrinsically foliation dependent. We expose the problem and discuss possible solutions using the Hawking-Hayward quasilocal mass. In spherical symmetry, we present a physically sensible approach to the problem by restricting to spherically symmetric spacetime slicings. In spherical symmetry, the apparent horizons enjoy a restricted gauge independence in any spherically symmetric foliation, but physical quantities associated with them, such as surface gravity and temperature, are fully gauge dependent. The widely used comoving and Kodama foliations, which are of particular interest, are discussed in detail as examples.

  11. 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.

  12. 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

  13. Moving Toward Polarimetry with the Event Horizon Telescope

    NASA Astrophysics Data System (ADS)

    Kosowsky, Michael; Fish, V. L.; Doeleman, S.; Johnson, M.; Lu, R.; Marrone, D. P.; Moran, J. M.; Plambeck, R. L.; Wardle, J. F.; EHT Collaboration

    2014-01-01

    The Event Horizon Telescope (EHT) project aims to develop millimeter and submillimeter VLBI to achieve angular resolution of tens of microarcseconds, comparable to the event horizons of nearby supermassive black holes. A major challenge for polarimetry at these scales is instrumental cross-talk, which introduces spurious linear polarization that can easily overwhelm the intrinsic signal. We demonstrate a new method for correcting the instrumental response, based on Markov Chain Monte Carlo simulations and other non-linear fitting methods. We will present preliminary polarimetric results on several EHT targets. Future EHT observations will provide a new window into the rich magnetic structures of their innermost cores.

  14. 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

  15. 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.

  16. Electrodynamics with a Future Conformal Horizon

    NASA Astrophysics Data System (ADS)

    Ibison, Michael

    2010-12-01

    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 ds2 = a2(t)(dt2-dx2) 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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