Geographical origin: meaningful reference or marketing tool?
DEFF Research Database (Denmark)
Hedegaard, Liselotte
2015-01-01
dimensions of local culture. The French label served as inspiration for the European PDO/PGI-labels, but even if these labels are known in Denmark only five products are PDO-branded The data-collection in Denmark indicated little trust in increased sales through PDO-labelling. This was contrary to data...... of production can be positioned on a map, but there is no precise standard for the rootedness of the product in this place. Origin means to be from a place in the sense that natural factors, cultural practices and historical links contribute to the understanding of the link between food and place...... origin was the result of a crisis in French wine-production in the early 20th century. Labelling was intended to protect the reputation of a product in terms of quality and taste by referring to parcels of land where specific traditions are maintained and the resulting products embedded in collective...
Benchmarking road safety performance: Identifying a meaningful reference (best-in-class).
Chen, Faan; Wu, Jiaorong; Chen, Xiaohong; Wang, Jianjun; Wang, Di
2016-01-01
For road safety improvement, comparing and benchmarking performance are widely advocated as the emerging and preferred approaches. However, there is currently no universally agreed upon approach for the process of road safety benchmarking, and performing the practice successfully is by no means easy. This is especially true for the two core activities of which: (1) developing a set of road safety performance indicators (SPIs) and combining them into a composite index; and (2) identifying a meaningful reference (best-in-class), one which has already obtained outstanding road safety practices. To this end, a scientific technique that can combine the multi-dimensional safety performance indicators (SPIs) into an overall index, and subsequently can identify the 'best-in-class' is urgently required. In this paper, the Entropy-embedded RSR (Rank-sum ratio), an innovative, scientific and systematic methodology is investigated with the aim of conducting the above two core tasks in an integrative and concise procedure, more specifically in a 'one-stop' way. Using a combination of results from other methods (e.g. the SUNflower approach) and other measures (e.g. Human Development Index) as a relevant reference, a given set of European countries are robustly ranked and grouped into several classes based on the composite Road Safety Index. Within each class the 'best-in-class' is then identified. By benchmarking road safety performance, the results serve to promote best practice, encourage the adoption of successful road safety strategies and measures and, more importantly, inspire the kind of political leadership needed to create a road transport system that maximizes safety. Copyright © 2015 Elsevier Ltd. All rights reserved.
Isolated Horizon, Killing Horizon and Event Horizon
Date, G.
2001-01-01
We consider space-times which in addition to admitting an isolated horizon also admit Killing horizons with or without an event horizon. We show that an isolated horizon is a Killing horizon provided either (1) it admits a stationary neighbourhood or (2) it admits a neighbourhood with two independent, commuting Killing vectors. A Killing horizon is always an isolated horizon. For the case when an event horizon is definable, all conceivable relative locations of isolated horizon and event hori...
International Nuclear Information System (INIS)
Hanni, R.S.
1975-01-01
The concept of the plasma horizon, defined as the boundary of the region in which an infinitely thin plasma can be supported against Coulomb attraction by a magnetic field, shows that the argument of selective accretion does not rule out the existence of charged black holes embedded in a conducting plasma. A detailed account of the covariant definition of plasma horizon is given and some examples of plasma horizons are presented. 7 references
Zhang, Eugene
2016-11-28
In this paper we seek to answer the following question: where do contour lines and visible contour lines (silhouette) tend to occur in a 3D surface. Our study leads to two novel shape descriptors, the horizon measure and the visible horizon measure, which we apply to the visualization of 3D shapes including archeological artifacts. In addition to introducing the shape descriptors, we also provide a closed-form formula for the horizon measure based on classical spherical geometry. To compute the visible horizon measure, which depends on the exact computation of the surface visibility function, we instead of provide an image-based approach which can process a model with high complexity within a few minutes.
Biederman, Joseph; Fitzgerald, Maura; Faraone, Stephen V.; Fried, Ronna; Woodworth, K. Yvonne; Saunders, Alexandra; Conroy, Kristina; Joshi, Gagan
2015-01-01
We previously described the high prevalence and burden of significant autistic traits (ATs) in youth with attention-deficit/hyperactivity disorder (ADHD). These traits are associated with significantly greater impairment in psychopathological, interpersonal, educational, and neuropsychological functioning. Because the sample consisted of referred ADHD youth, uncertainty remained regarding whether these findings are generalizable to non-referred populations of youths with and without ADHD.The ...
Energy Technology Data Exchange (ETDEWEB)
Giveon, Amit [Racah Institute of Physics, The Hebrew University,Jerusalem 91904 (Israel); Itzhaki, Nissan [Physics Department, Tel-Aviv University,Ramat-Aviv, 69978 (Israel); Kutasov, David [EFI and Department of Physics, University of Chicago,5640 S. Ellis Av., Chicago, IL 60637 (United States)
2015-06-11
We argue that classical (α{sup ′}) effects qualitatively modify the structure of Euclidean black hole horizons in string theory. While low energy modes experience the geometry familiar from general relativity, high energy ones see a rather different geometry, in which the Euclidean horizon can be penetrated by an amount that grows with the radial momentum of the probe. We discuss this in the exactly solvable SL(2,ℝ)/U(1) black hole, where it is a manifestation of the black hole/Sine-Liouville duality.
Energy Technology Data Exchange (ETDEWEB)
Larry G. Stolarczyk
2003-03-18
With the aid of a DOE grant (No. DE-FC26-01NT41050), Stolar Research Corporation (Stolar) developed the Horizon Sensor (HS) to distinguish between the different layers of a coal seam. Mounted on mining machine cutter drums, HS units can detect or sense the horizon between the coal seam and the roof and floor rock, providing the opportunity to accurately mine the section of the seam most desired. HS also enables accurate cutting of minimum height if that is the operator's objective. Often when cutting is done out-of-seam, the head-positioning function facilitates a fixed mining height to minimize dilution. With this technology, miners can still be at a remote location, yet cut only the clean coal, resulting in a much more efficient overall process. The objectives of this project were to demonstrate the feasibility of horizon sensing on mining machines and demonstrate that Horizon Sensing can allow coal to be cut cleaner and more efficiently. Stolar's primary goal was to develop the Horizon Sensor (HS) into an enabling technology for full or partial automation or ''agile mining''. This technical innovation (R&D 100 Award Winner) is quickly demonstrating improvements in productivity and miner safety at several prominent coal mines in the United States. In addition, the HS system can enable the cutting of cleaner coal. Stolar has driven the HS program on the philosophy that cutting cleaner coal means burning cleaner coal. The sensor, located inches from the cutting bits, is based upon the physics principles of a Resonant Microstrip Patch Antenna (RMPA). When it is in proximity of the rock-coal interface, the RMPA impedance varies depending on the thickness of uncut coal. The impedance is measured by the computer-controlled electronics and then sent by radio waves to the mining machine. The worker at the machine can read the data via a Graphical User Interface, displaying a color-coded image of the coal being cut, and direct the machine
Simonsen, I.; Jensen, M. H.; Johansen, A.
2002-06-01
In stochastic finance, one traditionally considers the return as a competitive measure of an asset, i.e., the profit generated by that asset after some fixed time span Δt, say one week or one year. This measures how well (or how bad) the asset performs over that given period of time. It has been established that the distribution of returns exhibits ``fat tails'' indicating that large returns occur more frequently than what is expected from standard Gaussian stochastic processes [1-3]. Instead of estimating this ``fat tail'' distribution of returns, we propose here an alternative approach, which is outlined by addressing the following question: What is the smallest time interval needed for an asset to cross a fixed return level of say 10%? For a particular asset, we refer to this time as the investment horizon and the corresponding distribution as the investment horizon distribution. This latter distribution complements that of returns and provides new and possibly crucial information for portfolio design and risk-management, as well as for pricing of more exotic options. By considering historical financial data, exemplified by the Dow Jones Industrial Average, we obtain a novel set of probability distributions for the investment horizons which can be used to estimate the optimal investment horizon for a stock or a future contract.
Siino, Masaru
1997-01-01
The topologies of event horizons are investigated. Considering the existence of the endpoint of the event horizon, it cannot be differentiable. Then there are the new possibilities of the topology of the event horizon though they are excluded in smooth event horizons. The relation between the topology of the event horizon and the endpoint of it is revealed. A torus event horizon is caused by two-dimensional endpoints. One-dimensional endpoints provide the coalescence of spherical event horizo...
Meaningful and Purposeful Practice
Clementi, Donna
2014-01-01
This article describes a graphic, designed by Clementi and Terrill, the authors of "Keys to Planning for Learning" (2013), visually representing the components that contribute to meaningful and purposeful practice in learning a world language, practice that leads to greater proficiency. The entire graphic is centered around the letter…
Heintzelman, Samantha J; King, Laura A
2014-09-01
The human experience of meaning in life is widely viewed as a cornerstone of well-being and a central human motivation. Self-reports of meaning in life relate to a host of important functional outcomes. Psychologists have portrayed meaning in life as simultaneously chronically lacking in human life as well as playing an important role in survival. Examining the growing literature on meaning in life, we address the question "How meaningful is life, in general?" We review possible answers from various psychological sources, some of which anticipate that meaning in life should be low and others that it should be high. Summaries of epidemiological data and research using two self-report measures of meaning in life suggest that life is pretty meaningful. Diverse samples rate themselves significantly above the midpoint on self-reports of meaning in life. We suggest that if meaning in life plays a role in adaptation, it must be commonplace, as our analysis suggests. (c) 2014 APA, all rights reserved.
Poignancy: Mixed Emotional Experience in the Face of Meaningful Endings
Ersner-Hershfield, Hal; Mikels, Joseph A.; Sullivan, Sarah J.; Carstensen, Laura L.
2009-01-01
The experience of mixed emotions increases with age. Socioemotional selectivity theory suggests that mixed emotions are associated with shifting time horizons. Theoretically, perceived constraints on future time increase appreciation for life, which, in turn, elicits positive emotions such as happiness. Yet, the very same temporal constraints heighten awareness that these positive experiences come to an end, thus yielding mixed emotional states. In 2 studies, the authors examined the link between the awareness of anticipated endings and mixed emotional experience. In Study 1, participants repeatedly imagined being in a meaningful location. Participants in the experimental condition imagined being in the meaningful location for the final time. Only participants who imagined “last times” at meaningful locations experienced more mixed emotions. In Study 2, college seniors reported their emotions on graduation day. Mixed emotions were higher when participants were reminded of the ending that they were experiencing. Findings suggest that poignancy is an emotional experience associated with meaningful endings. PMID:18179325
Mechanics of apparent horizons
International Nuclear Information System (INIS)
Collins, W.
1992-01-01
An equation for the variation in the surface area of an apparent horizon is derived which has the same form as the thermodynamic relation TdS=dQ. For a stationary vacuum black hole, the expression corresponding to a temperature equals the temperature of the event horizon. Also, if the black hole is perturbed infinitesimally by weak matter and gravitational fields, the area variation of the apparent horizon asymptotically approaches the Hartle-Hawking result for the event horizon. These results support the idea that a local version of black-hole thermodynamics in nonstationary systems can be constructed for apparent horizons
Beyond meaningful use: getting meaningful value from IT.
Fortin, Jason; Zywiak, Walt
2010-02-01
The HITECH provisions of ARRA include financial incentives for providers to demonstrate meaningful use of certified EHR technology. However, to maximize the value of IT under new payment models, provider organizations will need to go beyond meaningful use criteria in three key areas: Delivering high-quality care. Ensuring coordinated care. Integrating financial systems.
Smooth horizons and quantum ripples
International Nuclear Information System (INIS)
Golovnev, Alexey
2015-01-01
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. (orig.)
Smooth horizons and quantum ripples
Energy Technology Data Exchange (ETDEWEB)
Golovnev, Alexey [Saint Petersburg State University, High Energy Physics Department, Saint-Petersburg (Russian Federation)
2015-05-15
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. (orig.)
VMware horizon view essentials
von Oven, Peter
2014-01-01
If you are a desktop administrator or an end user of a computing project team looking to speed up to the latest VMware Horizon View solution, then this book is perfect for you. It is your ideal companion to deploy a solution to centrally manage and virtualize your desktop estate using Horizon View 6.0.
Optical geometry across the horizon
International Nuclear Information System (INIS)
Jonsson, Rickard
2006-01-01
In a recent paper (Jonsson and Westman 2006 Class. Quantum Grav. 23 61), a generalization of optical geometry, assuming a non-shearing reference congruence, is discussed. Here we illustrate that this formalism can be applied to (a finite four-volume) of any spherically symmetric spacetime. In particular we apply the formalism, using a non-static reference congruence, to do optical geometry across the horizon of a static black hole. While the resulting geometry in principle is time dependent, we can choose the reference congruence in such a manner that an embedding of the geometry always looks the same. Relative to the embedded geometry the reference points are then moving. We discuss the motion of photons, inertial forces and gyroscope precession in this framework
Proton surface charge determination in Spodosol horizons with organically bound aluminum
Skyllberg, Ulf; Borggaard, Ole K.
1998-05-01
Net proton surface charge densities were determined in O, E, Bh, and Bs horizons of a sandy till, Spodosol from Denmark, by means of acid-base titration combined with ion adsorption in 0.005 M Ca(NO 3) 2 and independent permanent charge determination. The release of organic anions exceeded the adsorption of NO 3-, resulting in a desorption of anions in all horizons. Data were found to obey the law of balance between surface charges and adsorbed ions only when charges pertaining to Al and organic anions released during the titration experiments were accounted for, in addition to charges pertaining the potential determining ions (PDI) H + and OH - and the index ions Ca 2+ and NO 3-. It was furthermore shown that the point of zero net proton charge (PZNPC) in soils highly depends on the concentration of organically bound Al. Approaches previously used in soils, in which adsorbed Al n+ has been ignored (i.e., considered equivalent to nH + as a PDI), resulted in a PZNPC of 4.1 in the Bs horizon. If instead organically bound Al was accounted for as a counter-ion similar to 3/2Ca 2+, a PZNPC of 2.9 was obtained for the same Bs horizon. Based on PZNPC values estimated by the latter approach, combined with a weak-acid analog, it was shown that organic proton surface charges buffered pH with a similar intensity in the O, E, Bh, and Bs horizons of this study. Because the acidity of Al adsorbed to conjugate bases of soil organic acids is substantially weaker than the acidity of the corresponding protonated form of the organic acids, the point of zero net proton charge (PZNPC) will increase if the concentration of organically adsorbed Al increases at the expense of adsorbed H. This means that PZNPC values determined for soils with unknown concentrations of organically adsorbed Al are highly operational and not very meaningful as references.
Revisiting event horizon finders
International Nuclear Information System (INIS)
Cohen, Michael I; Pfeiffer, Harald P; Scheel, Mark A
2009-01-01
Event horizons are the defining physical features of black hole spacetimes, and are of considerable interest in studying black hole dynamics. Here, we reconsider three techniques to find event horizons in numerical spacetimes: integrating geodesics, integrating a surface, and integrating a level-set of surfaces over a volume. We implement the first two techniques and find that straightforward integration of geodesics backward in time is most robust. We find that the exponential rate of approach of a null surface towards the event horizon of a spinning black hole equals the surface gravity of the black hole. In head-on mergers we are able to track quasi-normal ringing of the merged black hole through seven oscillations, covering a dynamic range of about 10 5 . Both at late times (when the final black hole has settled down) and at early times (before the merger), the apparent horizon is found to be an excellent approximation of the event horizon. In the head-on binary black hole merger, only some of the future null generators of the horizon are found to start from past null infinity; the others approach the event horizons of the individual black holes at times far before merger.
Parity horizons in shape dynamics
International Nuclear Information System (INIS)
Herczeg, Gabriel
2016-01-01
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. (paper)
Deepwater Horizon - Baseline Dataset
National Oceanic and Atmospheric Administration, Department of Commerce — In 2010, the Deepwater Horizon oil spill occurred in the Gulf of Mexico and the Natural Resources Damage Assessment (NRDA) was initiated to determine the extent of...
Psychological context of work meaningfulness
Directory of Open Access Journals (Sweden)
Karel Paulík
2014-12-01
Full Text Available There is a significant shift of approach to the management of organizations and workers in recent decades. This shift in management philosophy is characterized by converting from traditional, conventional (rather bureaucratic management models to rather humanistic/existential oriented models. This transition comes partly from the understanding that human resources are the most promising and effective way for organization development, partly from a shift in the understanding of the role of organizations in society. The key point of these approaches has become a "meaning" or "meaningfulness" in relation to the work and organization. The importance of work meaningfulness is not only in its potential to increase the competitiveness of organizations, but especially in its major (mostly positive impacts on the employee himself and his work (and by that the organization and its performance. Work meaningfulness is strongly connected to the work engagement, which represents the active personal participation in the work process, manifested by vigor, active cooperation, willingness to contribute to the company's success and dedication to work. Work engagement seems to be next important factor affecting work attitudes and achievements of employees. The paper gives an overview of various approaches to work meaningfulness and work engagement, on the basis of which authors propose new model of work meaningfulness with overlap to work engagement. The work meaningfulness is not seen as one-dimensional variable, but consists of complex of interacting factors and processes that define an individual perceived meaning and importance of the work. Meaningful work is influenced by three areas. The first is the organizational culture. This is defined as a specific pattern of values, norms, beliefs, attitudes and assumptions that are often not clearly expressed, but affect the way individuals behave in an organization and how things are done. The second area is the work
VMware Horizon Workspace essentials
von Oven, Peter; Lindberg, Joel
2014-01-01
This book uses a step-by-step approach to teach you how to design, deploy, and manage a Horizon Workspace based on real world experience. Written in an easy-to-follow style, this book explains the terminology in a clear and concise manner. Each feature is explained starting at a high level and then drilling down into the technical detail, using diagrams and screenshots.This book is perfect for IT administrators who want to deploy a solution to centrally manage access to corporate applications, data, and virtual desktops using Horizon Workspace. You need to have some experience in delivering BY
Oven, Peter von
2015-01-01
If you are working as a desktop admin, part of a EUC team, an architect, or a consultant on a desktop virtualization project and you are looking to use VMware's Horizon solution, this book is for you. This book will demonstrate the new capabilities of Horizon 6. You should have experience in desktop management using Windows and Microsoft Office, and be familiar with Active Directory, SQL, Windows Remote Desktop Session Hosting, and VMware vSphere infrastructure (ESXi and vCenter Server) technology.
Bootstrap, universality and horizons
Energy Technology Data Exchange (ETDEWEB)
Chang, Chi-Ming [Center for Theoretical Physics and Department of Physics,University of California, Berkeley, CA 94704 (United States); Lin, Ying-Hsuan [Jefferson Physical Laboratory, Harvard University,Cambridge, MA 02138 (United States)
2016-10-13
We present a closed form expression for the semiclassical OPE coefficients that are universal for all 2D CFTs with a “weak” light spectrum, by taking the semiclassical limit of the fusion kernel. We match this with a properly regularized and normalized bulk action evaluated on a geometry with three conical defects, analytically continued in the deficit angles beyond the range for which a metric with positive signature exists. The analytically continued geometry has a codimension-one coordinate singularity surrounding the heaviest conical defect. This singularity becomes a horizon after Wick rotating to Lorentzian signature, suggesting a connection between universality and the existence of a horizon.
Sediment Sampling Data for BP Spill/Deepwater Horizon
U.S. Environmental Protection Agency — 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...
Air Sampling Data for BP Spill/Deepwater Horizon
U.S. Environmental Protection Agency — 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...
Waste Sampling Data for BP Spill/Deepwater Horizon
U.S. Environmental Protection Agency — 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...
Air Monitoring Data for BP Spill/Deepwater Horizon
U.S. Environmental Protection Agency — 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...
Surface Water Sampling Data for BP Spill/Deepwater Horizon
U.S. Environmental Protection Agency — 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...
Water Sampling Data for BP Spill/Deepwater Horizon
U.S. Environmental Protection Agency — 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 spatial relation between the event horizon and trapping horizon
International Nuclear Information System (INIS)
Nielsen, Alex B
2010-01-01
The relation between event horizons and trapping horizons is investigated in a number of different situations with emphasis on their role in thermodynamics. A notion of constant change is introduced that in certain situations allows the location of the event horizon to be found locally. When the black hole is accreting matter the difference in area between the two different horizons can be many orders of magnitude larger than the Planck area. When the black hole is evaporating, the difference is small on the Planck scale. A model is introduced that shows how trapping horizons can be expected to appear outside the event horizon before the black hole starts to evaporate. Finally, a modified definition is introduced to invariantly define the location of the trapping horizon under a conformal transformation. In this case the trapping horizon is not always a marginally outer trapped surface.
Instability of enclosed horizons
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.
Spacetimes containing slowly evolving horizons
International Nuclear Information System (INIS)
Kavanagh, William; Booth, Ivan
2006-01-01
Slowly evolving horizons are trapping horizons that are ''almost'' isolated horizons. This paper reviews their definition and discusses several spacetimes containing such structures. These include certain Vaidya and Tolman-Bondi solutions as well as (perturbatively) tidally distorted black holes. Taking into account the mass scales and orders of magnitude that arise in these calculations, we conjecture that slowly evolving horizons are the norm rather than the exception in astrophysical processes that involve stellar-scale black holes
Energy Technology Data Exchange (ETDEWEB)
Gao, Fei; Qin, Si-Xue; Roberts, Craig D.; Rodríguez-Quintero, Jose
2018-02-01
We explore whether a tree-level expression for the gluon two-point function, supposed to express effects of an horizon term introduced to eliminate the Gribov ambiguity, is consistent with the propagator obtained in simulations of lattice-regularised quantum chromodynamics (QCD). In doing so, we insist that the gluon two-point function obey constraints that ensure a minimal level of consistency with parton-like behaviour at ultraviolet momenta. In consequence, we are led to a position which supports a conjecture that the gluon mass and horizon scale are equivalent emergent massscales, each with a value of roughly 0.5 GeV; and wherefrom it appears plausible that the dynamical generation of a running gluon mass may alone be sufficient to remove the Gribov ambiguity.
Horizon Scanning for Pharmaceuticals
DEFF Research Database (Denmark)
Lepage-Nefkens, Isabelle; Douw, Karla; Mantjes, GertJan
for a joint horizon scanning system (HSS). We propose to create a central “horizon scanning unit” to perform the joint HS activities (a newly established unit, an existing HS unit, or a third party commissioned and financed by the collaborating countries). The unit will be responsible for the identification...... and filtration of new and emerging pharmaceutical products. It will maintain and update the HS database, organise company pipeline meetings, and disseminate the HSS’s outputs. The HS unit works closely together with the designated national HS experts in each collaborating country. The national HS experts...... will collect country-specific information, liaise between the central HS unit and country-specific clinical and other experts, coordinate the national prioritization process (to select products for early assessment), and communicate the output of the HSS to national decision makers. The outputs of the joint...
Gao, Fei; Qin, Si-Xue; Roberts, Craig D.; Rodríguez-Quintero, Jose
2018-02-01
We explore whether a tree-level expression for the gluon two-point function, supposed to express effects of an horizon term introduced to eliminate the Gribov ambiguity, is consistent with the propagator obtained in simulations of lattice-regularized quantum chromodynamics (QCD). In doing so, we insist that the gluon two-point function obey constraints that ensure a minimal level of consistency with parton-like behavior on the ultraviolet domain. In consequence, we are led to a position which supports a conjecture that the gluon mass and horizon scale are equivalent emergent mass-scales, each with a value of roughly 0.5 GeV; and wherefrom it appears plausible that the dynamical generation of a running gluon mass may alone be sufficient to remove the Gribov ambiguity.
Joannah Caborn Wengler
2012-01-01
Every tenth member of the CERN personnel participates in an EU-funded project – a strong indication of CERN’s successful relations with the European Commission (EC), coordinated by the CERN EU projects office. The EC director in charge of preparing “Horizon 2020”, the new EU funding programme for research and innovation (2014-2020), will be giving a presentation at CERN on 8 May. He will reveal more about what the new programme has in store. “It’s a very interesting time in the development of Horizon 2020, which is focusing the attention of all research communities in Europe,” explains Svetlomir Stavrev, head of the EU projects office. “After a long public consultation and drafting process, the Horizon 2020 proposal documents are now being reviewed by the European Parliament and Council.” CERN already participated in the consultation, making good use of the opportunity to contribute to the shaping of wh...
Infinite-horizon optimal control problems in economics
Energy Technology Data Exchange (ETDEWEB)
Aseev, Sergei M; Besov, Konstantin O; Kryazhimskii, Arkadii V
2012-04-30
This paper extends optimal control theory to a class of infinite-horizon problems that arise in studying models of optimal dynamic allocation of economic resources. In a typical problem of this sort the initial state is fixed, no constraints are imposed on the behaviour of the admissible trajectories at large times, and the objective functional is given by a discounted improper integral. We develop the method of finite-horizon approximations in a broad context and use it to derive complete versions of the Pontryagin maximum principle for such problems. We provide sufficient conditions for the normality of infinite-horizon optimal control problems and for the validity of the 'standard' limit transversality conditions with time going to infinity. As a meaningful example, we consider a new two-sector model of optimal economic growth subject to a random jump in prices. Bibliography: 53 titles.
Infinite-horizon optimal control problems in economics
International Nuclear Information System (INIS)
Aseev, Sergei M; Besov, Konstantin O; Kryazhimskii, Arkadii V
2012-01-01
This paper extends optimal control theory to a class of infinite-horizon problems that arise in studying models of optimal dynamic allocation of economic resources. In a typical problem of this sort the initial state is fixed, no constraints are imposed on the behaviour of the admissible trajectories at large times, and the objective functional is given by a discounted improper integral. We develop the method of finite-horizon approximations in a broad context and use it to derive complete versions of the Pontryagin maximum principle for such problems. We provide sufficient conditions for the normality of infinite-horizon optimal control problems and for the validity of the 'standard' limit transversality conditions with time going to infinity. As a meaningful example, we consider a new two-sector model of optimal economic growth subject to a random jump in prices. Bibliography: 53 titles.
Building Bridges Through Meaningful Occupation
Directory of Open Access Journals (Sweden)
Jennifer Fortuna
2017-07-01
Full Text Available Mary Block, MS, OTR/L, an occupational therapist and artist based in Illinois, provided the cover art for the Summer 2017 issue of The Open Journal of Occupational Therapy (OJOT. Generations is a sculpture made from concrete that measures 240 x100 in. (6.096 x 2.54 m. The piece was commissioned by Mary’s home town, the Village of Deerfield, IL. Mary always knew she wanted to be an artist. When competing paradigms altered Mary’s career path, the field of occupational therapy helped her to shape a new worldview. In uncertain times, meaningful occupation empowered Mary to start over again where she originally began
Spacetimes foliated by Killing horizons
International Nuclear Information System (INIS)
Pawlowski, Tomasz; Lewandowski, Jerzy; Jezierski, Jacek
2004-01-01
It seems to be expected that a horizon of a quasi-local type, such as a Killing or an isolated horizon, by analogy with a globally defined event horizon, should be unique in some open neighbourhood in the spacetime, provided the vacuum Einstein or the Einstein-Maxwell equations are satisfied. The aim of our paper is to verify whether that intuition is correct. If one can extend a so-called Kundt metric, in such a way that its null, shear-free surfaces have spherical spacetime sections, the resulting spacetime is foliated by so-called non-expanding horizons. The obstacle is Kundt's constraint induced at the surfaces by the Einstein or the Einstein-Maxwell equations, and the requirement that a solution be globally defined on the sphere. We derived a transformation (reflection) that creates a solution to Kundt's constraint out of data defining an extremal isolated horizon. Using that transformation, we derived a class of exact solutions to the Einstein or Einstein-Maxwell equations of very special properties. Each spacetime we construct is foliated by a family of the Killing horizons. Moreover, it admits another, transversal Killing horizon. The intrinsic and extrinsic geometries of the transversal Killing horizon coincide with the one defined on the event horizon of the extremal Kerr-Newman solution. However, the Killing horizon in our example admits yet another Killing vector tangent to and null at it. The geometries of the leaves are given by the reflection
VMware Horizon Mirage essentials
Von Oven, Peter
2013-01-01
This book provides a practical, step-by-step approach to teach you how to build a successful infrastructure.This book is perfect for desktop administrators who want to deploy a solution to centrally manage their endpoint images across their entire estate using VMware Horizon Mirage. You need to have some experience in desktop image management using Microsoft Windows operating systems and Windows applications, as well as be familiar with Active Directory, SQL, IIS, and general server infrastructure relating to supporting end users.
Silk, Joseph
2011-01-01
Horizons of Cosmology: Exploring Worlds Seen and Unseen is the fourth title published in the Templeton Science and Religion Series, in which scientists from a wide range of fields distill their experience and knowledge into brief tours of their respective specialties. In this volume, highly esteemed astrophysicist Joseph Silk explores the vast mysteries and speculations of the field of cosmology in a way that balances an accessible style for the general reader and enough technical detail for advanced students and professionals. Indeed, while the p
Kaltenhauser, Kristin
2015-01-01
Expanding your horizons is a bi-annual “Science Day” for girls aged 11 to 14, held at the University of Geneva on 14 November. The girls had the opportunity to take part in hands-on workshops held by local professional women in the field of science, mathematics, engineering and technology. For the fourth time, CERN was part of this event, offering three workshops as well as a booth at the Discovery Fair, including Higgnite, an interactive visualization of the Higgs Field.
Energy Technology Data Exchange (ETDEWEB)
Giveon, Amit [Racah Institute of Physics, The Hebrew University,Jerusalem 91904 (Israel); Itzhaki, Nissan [Physics Department, Tel-Aviv University,Ramat-Aviv, 69978 (Israel); Kutasov, David [EFI and Department of Physics, University of Chicago,5640 S. Ellis Av., Chicago, IL 60637 (United States)
2016-10-28
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.
Near horizon structure of extremal vanishing horizon black holes
Directory of Open Access Journals (Sweden)
S. Sadeghian
2015-11-01
Full Text Available We study the near horizon structure of Extremal Vanishing Horizon (EVH black holes, extremal black holes with vanishing horizon area with a vanishing one-cycle on the horizon. We construct the most general near horizon EVH and near-EVH ansatz for the metric and other fields, like dilaton and gauge fields which may be present in the theory. We prove that (1 the near horizon EVH geometry for generic gravity theory in generic dimension has a three dimensional maximally symmetric subspace; (2 if the matter fields of the theory satisfy strong energy condition either this 3d part is AdS3, or the solution is a direct product of a locally 3d flat space and a d−3 dimensional part; (3 these results extend to the near horizon geometry of near-EVH black holes, for which the AdS3 part is replaced with BTZ geometry. We present some specific near horizon EVH geometries in 3, 4 and 5 dimensions for which there is a classification. We also briefly discuss implications of these generic results for generic (gauged supergravity theories and also for the thermodynamics of near-EVH black holes and the EVH/CFT proposal.
Cauchy horizons in Gowdy spacetimes
International Nuclear Information System (INIS)
Chrusciel, Piotr T; Lake, Kayll
2004-01-01
We analyse exhaustively the structure of non-degenerate Cauchy horizons in Gowdy spacetimes, and we establish existence of a large class of non-polarized Gowdy spacetimes with such horizons. Our results here, together with the deep new results of Ringstroem, establish strong cosmic censorship in (toroidal) Gowdy spacetimes
Concept maps and the meaningful learning of science
Directory of Open Access Journals (Sweden)
José Antonio C. S. Valadares
2013-03-01
Full Text Available The foundations of the Meaningful Learning Theory (MLT were laid by David Ausubel. The MLT was highly valued by the contributions of Joseph Novak and D. B. Gowin. Unlike other learning theories, the MLT has an operational component, since there are some instruments based on it and with the meaningful learning facilitation as aim. These tools were designated graphic organizers by John Trowbridge and James Wandersee (2000, pp. 100-129. One of them is the concept map created by Novak to extract meanings from an amalgam of information, having currently many applications. The other one is the Vee diagram or knowledge Vee, also called epistemological Vee or heuristic Vee. It was created by Gowin, and is an excellent organizer, for example to unpack and make transparent the unclear information from an information source. Both instruments help us in processing and becoming conceptually transparent the information, to facilitate the cognitive process of new meanings construction. In this work, after a brief introduction, it will be developed the epistemological and psychological grounds of MLT, followed by a reference to constructivist learning environments facilitators of the meaningful learning, the characterization of concept maps and exemplification of its use in various applications that have proved to be very effective from the standpoint of meaningful learning.
Three theorems on near horizon extremal vanishing horizon geometries
Directory of Open Access Journals (Sweden)
S. Sadeghian
2016-02-01
Full Text Available EVH black holes are Extremal black holes with Vanishing Horizon area, where vanishing of horizon area is a result of having a vanishing one-cycle on the horizon. We prove three theorems regarding near horizon geometry of EVH black hole solutions to generic Einstein gravity theories in diverse dimensions. These generic gravity theories are Einstein–Maxwell-dilaton-Λ theories, and gauged or ungauged supergravity theories with U(1 Maxwell fields. Our three theorems are: (1 The near horizon geometry of any EVH black hole has a three dimensional maximally symmetric subspace. (2 If the energy momentum tensor of the theory satisfies strong energy condition either this 3d part is an AdS3, or the solution is a direct product of a locally 3d flat space and a d−3 dimensional part. (3 These results extend to the near horizon geometry of near-EVH black holes, for which the AdS3 part is replaced with BTZ geometry.
Killing Horizons as Equipotential Hypersurfaces
Smolić, Ivica
2012-01-01
In this note we present a new proof that Killing horizons are equipotential hypersurfaces for the electric and the magnetic scalar potential, that makes no use of gravitational field equations or the assumption about the existence of bifurcation surface.
Reflections on Meaningfulness and its Social Relevance
Directory of Open Access Journals (Sweden)
Nicole Note
2010-06-01
Full Text Available Philosophers who write about the meaning of life are few nowadays. Thesubject has lost its attractiveness. Perceived from a viewpoint of logical positivism or language philosophy, the whole issue of meaningfulness seems rather pointless. It is often considered to be related to metaphysics, making it less suitable for philosophical inquiry. The topic of meaningfulness seems too intangible. Indeed, the few philosophers that have embarked on examining meaningfulness have proven to be well aware of the challenges this poses. At times they acknowledge that the more they concentrate on the subject, the more it seems to fall apart into unintelligible pieces about whichnothing of philosophical value can be said.
A meaningful workplace: Framework, space and context ...
African Journals Online (AJOL)
A meaningful workplace: Framework, space and context. ... PL Steenkamp, JS Basson ... The organisation experiences a loss of productivity, quality, innovation, et cetera ... This is what this article is about: to conceptualise the workplace as ...
Making Social Studies Meaningful to Elementary Students.
Klein, Susan
1982-01-01
Describes a unit on Ancient Greece designed to make social studies meaningful to fourth and fifth graders. Individual projects and group activities helped students learn about ancient Greek culture. (AM)
Meaningful work, work engagement and organisational commitment
Directory of Open Access Journals (Sweden)
Madelyn Geldenhuys
2014-03-01
Research purpose: The aim of the study was to investigate the relationships amongst psychological meaningfulness, work engagement and organisational commitment and to test for a possible mediation effect of work engagement on the relationship between psychological meaningfulness and organisational commitment. Motivation for the study: Managers have to rethink ways of improving productivity and performance at work, due to the diverse, and in some instances escalating, needs of employees (e.g. financial support to uphold their interest in and enjoyment of working. Research approach, design and method: A quantitative approach was employed to gather the data for the study, utilising a cross-sectional survey design. The sample (n = 415 consisted of working employees from various companies and positions in Gauteng, South Africa. Main findings: The results confirmed a positive relationship between psychological meaningfulness, work engagement and organisational commitment. Further, psychological meaningfulness predicts work engagement, whilst psychological meaningfulness and work engagement predict organisational commitment. Practical/managerial implications: Employers identifying their employees’ commitment patterns and mapping out strategies for enhancing those that are relevant to organisational goals will yield positive work outcomes (e.g. employees who are creative, seek growth or challenges for themselves. Contribution/value-add: This study contributes to the literature through highlighting the impact that meaningful work has on sustaining employee commitment to the organisation.
Electrodynamics of the event horizon
International Nuclear Information System (INIS)
Punsly, B.; Coroniti, F.V.
1989-01-01
This paper is an investigation of the electrodynamics of the event horizon of a Kerr black hole. It is demonstrated that the event horizon behaves quite generally as an asymptotic vacuum infinity for axisymmetric, charge-neutral, accreting electromagnetic sources. This is in contrast with the general notion that the event horizon can be treated as an imperfect conductive membrane with a surface impedance of 4π/c. The conductive-membrane model has been incorporated into the more sophisticated membrane paradigm of Thorne, Price, and Macdonald by supplementing the model with the full equations of general relativity. In certain situations (in particular those of astrophysical interest), the conductive-membrane interpretation forms the appropriate set of pictures and images in the membrane paradigm. In this paper we reevaluate the specific gedanken experiments that were originally used to motivate the paradigm. We find that great care must be exercised if the detailed interaction of a black hole's external gravitational field with a magnetized plasma is modeled by the electrodynamics of the conductive horizon membrane. For ingoing flows of plasma or electromagnetic waves (when the hole is passively accepting information), the interpretation of the horizon as a vacuum infinity is equivalent to an imperfect conductor with a surface impedance of 4π/c (the impedance of the vacuum). In situations when an imperfect conductor should radiate information (such as a Faraday wheel) the event horizon cannot, since it is an infinity. The event horizon does not behave quite generally as an imperfect conductor, but has electrodynamic properties unique to itself
Moving Horizon Estimation and Control
DEFF Research Database (Denmark)
Jørgensen, John Bagterp
successful and applied methodology beyond PID-control for control of industrial processes. The main contribution of this thesis is introduction and definition of the extended linear quadratic optimal control problem for solution of numerical problems arising in moving horizon estimation and control...... problems. Chapter 1 motivates moving horizon estimation and control as a paradigm for control of industrial processes. It introduces the extended linear quadratic control problem and discusses its central role in moving horizon estimation and control. Introduction, application and efficient solution....... It provides an algorithm for computation of the maximal output admissible set for linear model predictive control. Appendix D provides results concerning linear regression. Appendix E discuss prediction error methods for identification of linear models tailored for model predictive control....
Plasmonic Horizon in Gold Nanosponges.
Vidal, Cynthia; Sivun, Dmitry; Ziegler, Johannes; Wang, Dong; Schaaf, Peter; Hrelescu, Calin; Klar, Thomas A
2018-02-14
An electromagnetic wave impinging on a gold nanosponge coherently excites many electromagnetic hot-spots inside the nanosponge, yielding a polarization-dependent scattering spectrum. In contrast, a hole, recombining with an electron, can locally excite plasmonic hot-spots only within a horizon given by the lifetime of localized plasmons and the speed carrying the information that a plasmon has been created. This horizon is about 57 nm, decreasing with increasing size of the nanosponge. Consequently, photoluminescence from large gold nanosponges appears unpolarized.
A theory of planning horizons (1: market design in a post-neoclassical world
Directory of Open Access Journals (Sweden)
Frederic B. Jennings, Jr.
2012-05-01
Full Text Available The neoclassical case supporting competitive frames and market solutions has failed to promote stable world-wide economic development. Other approaches in economics incorporate social culture, increasing returns, market power, ecological limits and complementarity, yielding broader applications for development theory. In this paper a theory of planning horizons is introduced to raise some meaningful questions about the traditional view with respect to its substitution, decreasing returns and independence assumptions. Suppositions of complementarity, increasing returns and interdependence suggest that competition is inefficient by upholding a myopic culture resistant to learning. Growth – though long believed to rise from markets and competitive values – may not derive from these sources. Instead, as civilizations advance, shifting from material wants to higher-order intangible output, they evolve from market tradeoffs (substitution and scarcity into realms of common need (complementarity and abundance. The policy implications of horizonal theory are explored, with respect to regulatory aims and economic concerns. Such an approach emphasizes strict constraints against entry barriers, ecological harm, market power abuse and ethical lapses. Social cohesion – not competition – is sought as a means to extend horizons and thereby increase efficiency, equity and ecological health. The overriding importance of horizon effects for regulatory assessment dominates other orthodox standards in economics and law. Reframing economics along horizonal lines suggests some meaningful insight on the proper design of economic systems.
Black holes or firewalls: A theory of horizons
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.
Neighborhoods of isolated horizons and their stationarity
International Nuclear Information System (INIS)
Lewandowski, Jerzy; Pawłowski, Tomasz
2014-01-01
A distinguished (invariant) Bondi-like coordinate system is defined in the spacetime neighborhood of a non-expanding horizon of arbitrary dimension via geometry invariants of the horizon. With its use, the radial expansion of a spacetime metric about the horizon is provided and the free data needed to specify it up to a given order are determined in spacetime dimension 4. For the case of an electro-vacuum horizon in four-dimensional spacetime, the necessary and sufficient conditions for the existence of a Killing field at its neighborhood are identified as differential conditions for the horizon data and data for the null surface transversal to the horizon. (paper)
Meaningful Interaction in a Local Context
DEFF Research Database (Denmark)
Holck, Ulla
2006-01-01
This keynote is based on a Ph.D. thesis on development of socially meaningful interaction in music therapy with children with very poor communication skills (Holck 2002). The aim was to identify some of the conditions, whereby actions can be understood as meaningful - that is, whereby the child......’ Samspil i Musikterapi [Eng.: ’Commusical’ Interplay in Music Therapy. Qualitative Video Analyses of Musical and Gestural Interactions with Children with Severe Functional Limitations, including Children with Autism]. Unpubl. PhD thesis, Aalborg Universitet. Holck, U. (2004) Interaction Themes in Music...
Cavallo, Ann Liberatore
This 1-week study explored the extent to which high school students (n=140) acquired meaningful understanding of selected biological topics (meiosis and the Punnett square method) and the relationship between these topics. This study: (1) examined "mental modeling" as a technique for measuring students' meaningful understanding of the…
Event horizon and scalar potential
International Nuclear Information System (INIS)
Duruisseau, J.P.; Tonnelat, M.A.
1977-01-01
The introduction of a scalar potential with a more general scheme than General Relativity eliminates the event horizon. Among possible solutions, the Schwarzschild one represents a singular case. A study of the geodesic properties of the matching with an approximated interior solution are given. A new definition of the gravitational mass and chi function is deduced. (author)
New Horizons in Education, 2000.
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…
Killing horizons as equipotential hypersurfaces
International Nuclear Information System (INIS)
Smolić, Ivica
2012-01-01
In this note we present a new proof that Killing horizons are equipotential hypersurfaces for the electric and the magnetic scalar potential, which makes no use of gravitational field equations or the assumption about the existence of a bifurcation surface. (note)
Protestant ethic: Contributing towards a meaningful workplace ...
African Journals Online (AJOL)
The article also indicates that the Protestant ethic can indeed contribute towards a meaningful experience whilst performing work-related tasks in workspace. The Protestant work ethic is more than a cultural norm that places a positive moral value on doing a good job. Based on a belief that work has intrinsic value for its own ...
Remedial principles and meaningful engagement in education ...
African Journals Online (AJOL)
This article evaluates the meaningful engagement doctrine in the education rights jurisprudence of the Constitutional Court in the light of a set of normative principles developed by Susan Sturm for evaluating participatory public law remedies. It commences by identifying four principles for evaluating participatory remedies ...
Meaningful Learning in the Cooperative Classroom
Sharan, Yael
2015-01-01
Meaningful learning is based on more than what teachers transmit; it promotes the construction of knowledge out of learners' experience, feelings and exchanges with other learners. This educational view is based on the constructivist approach to learning and the co-operative learning approach. Researchers and practitioners in various…
Meaningful Use of School Health Data
Johnson, Kathleen Hoy; Bergren, Martha Dewey
2011-01-01
Meaningful use (MU) of Electronic Health Records (EHRs) is an important development in the safety and security of health care delivery in the United States. Advancement in the use of EHRs occurred with the passage of the American Recovery and Reinvestment Act of 2009, which provides incentives for providers to support adoption and use of EHRs.…
Wonderful Life : Exploring Wonder in Meaningful Moments
van de Goor, Marie Jacqueline; Sools, Anna Maria; Westerhof, Gerben Johan; Bohlmeijer, Ernst Thomas
In this article, we bring the study of meaning together with the emerging field of study focusing on the emotions of wonder: wonder, enchantment, awe, and being moved. It is in meaningful moments that these two meet, and in our empirical study, we used the emotions of wonder as a lens to investigate
Assessing Assessment: In Pursuit of Meaningful Learning
Rootman-le Grange, Ilse; Blackie, Margaret A. L.
2018-01-01
The challenge of supporting the development of meaningful learning is prevalent in chemistry education research. One of the core activities used in the learning process is assessments. The aim of this paper is to illustrate how the semantics dimension of Legitimation Code Theory can be a helpful tool to critique the quality of assessments and…
Fishing for meaningful units in connected speech
DEFF Research Database (Denmark)
Henrichsen, Peter Juel; Christiansen, Thomas Ulrich
2009-01-01
In many branches of spoken language analysis including ASR, the set of smallest meaningful units of speech is taken to coincide with the set of phones or phonemes. However, fishing for phones is difficult, error-prone, and computationally expensive. We present an experiment, based on machine...
Gamlin, Peter J.
1971-01-01
Examines the effects of short term memory (STM) capacity, meaningfulness of stimuli, and age upon listeners' structuring of sentences. Results show that the interaction between STM capacity and meaningfulness (1) approached significance when data were collapsed over both age levels, and (2) was significant for one age level. Tables and references.…
Cosmological and black hole apparent horizons
Faraoni, Valerio
2015-01-01
This book overviews the extensive literature on apparent cosmological and black hole horizons. In theoretical gravity, dynamical situations such as gravitational collapse, black hole evaporation, and black holes interacting with non-trivial environments, as well as the attempts to model gravitational waves occurring in highly dynamical astrophysical processes, require that the concept of event horizon be generalized. Inequivalent notions of horizon abound in the technical literature and are discussed in this manuscript. The book begins with a quick review of basic material in the first one and a half chapters, establishing a unified notation. Chapter 2 reminds the reader of the basic tools used in the analysis of horizons and reviews the various definitions of horizons appearing in the literature. Cosmological horizons are the playground in which one should take baby steps in understanding horizon physics. Chapter 3 analyzes cosmological horizons, their proposed thermodynamics, and several coordinate systems....
Entropy of black holes with multiple horizons
He, Yun; Ma, Meng-Sen; Zhao, Ren
2018-05-01
We examine the entropy of black holes in de Sitter space and black holes surrounded by quintessence. These black holes have multiple horizons, including at least the black hole event horizon and a horizon outside it (cosmological horizon for de Sitter black holes and "quintessence horizon" for the black holes surrounded by quintessence). Based on the consideration that the two horizons are not independent each other, we conjecture that the total entropy of these black holes should not be simply the sum of entropies of the two horizons, but should have an extra term coming from the correlations between the two horizons. Different from our previous works, in this paper we consider the cosmological constant as the variable and employ an effective method to derive the explicit form of the entropy. We also try to discuss the thermodynamic stabilities of these black holes according to the entropy and the effective temperature.
Hawking radiation from quasilocal dynamical horizons
Indian Academy of Sciences (India)
2016-01-06
Jan 6, 2016 ... Abstract. In completely local settings, we establish that a dynamically evolving spherically symmetric black hole horizon can be assigned a Hawking temperature and with the emission of flux, radius of the horizon shrinks.
Pricing Liquidity Risk with Heterogeneous Investment Horizons
Beber, Alessandro; Driessen, Joost; Neuberger, A.; Tuijp, P
We develop an asset pricing model with stochastic transaction costs and investors with heterogeneous horizons. Depending on their horizon, investors hold different sets of assets in equilibrium. This generates segmentation and spillover effects for expected returns, where the liquidity (risk)
Event horizon image within black hole shadow
Dokuchaev, V. I.; Nazarova, N. O.
2018-01-01
The external border of the black hole shadow is washed out by radiation from matter plunging into black hole and approaching the event horizon. This effect will crucially influence the results of future observations by the Event Horizon Telescope. We show that gravitational lensing of the luminous matter plunging into black hole provides the event horizon visualization within black hole shadow. The lensed image of the event horizon is formed by the last highly red-shifted photons emitted by t...
Ennis, Kim; Priebe, Carly; Sharipova, Mayya; West, Kim
2012-01-01
Revealing the core of a teaching philosophy is the key to a concise and meaningful philosophy statement, but it can be an elusive goal. This paper offers a visual, kinesthetic, and holistic process for expanding the horizons of self-reflection, self-analysis, and self-knowledge. Mystery montage, a variation of visual mapping, storyboarding, and…
Horizon Detection In The Visible Spectrum
2016-09-01
processing units, to the software-based models in [7] and [8]. B. DEFINING THE HORIZON The horizon, according to the Oxford English Dictionary , is “the...Ed. Dordrecht, Holland: D. Reidel Publishing Company, 1978. [10] “horizon,” Oxford English Dictionary Online, 2016.[Online]. Available: http
78 FR 54298 - Horizons ETFs Management (USA) LLC and Horizons ETF Trust; Notice of Application
2013-09-03
... ETFs Management (USA) LLC and Horizons ETF Trust; Notice of Application August 27, 2013. AGENCY... Management (USA) LLC (``Horizons'') and Horizons ETF Trust (the ``Trust''). Summary of Application... of the Trust will be the Horizons Active Global Dividend ETF (the ``Initial Fund''), which will seek...
Cosmological horizons and reconstruction of quantum field theories
International Nuclear Information System (INIS)
Dappiaggi, C.; Pinamonti, N.
2007-12-01
As a starting point for this manuscript, we remark how the cosmological horizon of a certain class of Friedmann-Robertson-Walker backgrounds shares some non trivial geometric properties with null infinity in an asymptotically flat spacetime. Such a feature is generalized to a larger class of expanding spacetimes M admitting a geodesically complete cosmological horizon J - common to all co-moving observers. This property is later exploited in order to recast, in a cosmological background, some recent results for a linear scalar quantum field theory in spacetimes asymptotically flat at null infinity. Under suitable hypotheses on M - valid for de Sitter spacetime and some other FRW spacetimes obtained by perturbing deSitter space - the algebra of observables for a Klein-Gordon field is mapped into a subalgebra of the algebra of observables W(J - ) constructed on the cosmological horizon. There is exactly one pure quasifree state λ on W(J - ) which fulfills a suitable energy positivity condition with respect to a generator related with the cosmological time displacements. Furthermore λ induces a preferred physically meaningful quantum state λ M for the quantum theory in the bulk. If M admits a timelike Killing generator preserving J - , then the associated self-adjoint generator in the GNS representation of λ M has positive spectrum (i.e. energy). Moreover λ M turns out to be invariant under every symmetry of the bulk metric which preserves the cosmological horizon. In the case of an expanding de Sitter spacetime, λ M coincides with the Euclidean (Bunch-Davies) vacuum state, hence being Hadamard in this case. Remarks on the validity of the Hadamard property for λ M in more general spacetimes are presented. (orig.)
Cosmological horizons and reconstruction of quantum field theories
Energy Technology Data Exchange (ETDEWEB)
Dappiaggi, C.; Pinamonti, N. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik]|[Trento Univ., Povo (Italy). Istituto Nazionale di Alta Matematica ' ' F. Severi' ' - GNFM; Moretti, V. [Trento Univ. (Italy). Dipt. di Matematica]|[Istituto Nazionale di Fisica Nucleare - Gruppo Collegato di Trento, Povo (Italy)
2007-12-15
As a starting point for this manuscript, we remark how the cosmological horizon of a certain class of Friedmann-Robertson-Walker backgrounds shares some non trivial geometric properties with null infinity in an asymptotically flat spacetime. Such a feature is generalized to a larger class of expanding spacetimes M admitting a geodesically complete cosmological horizon J{sup -} common to all co-moving observers. This property is later exploited in order to recast, in a cosmological background, some recent results for a linear scalar quantum field theory in spacetimes asymptotically flat at null infinity. Under suitable hypotheses on M - valid for de Sitter spacetime and some other FRW spacetimes obtained by perturbing deSitter space - the algebra of observables for a Klein-Gordon field is mapped into a subalgebra of the algebra of observables W(J{sup -}) constructed on the cosmological horizon. There is exactly one pure quasifree state {lambda} on W(J{sup -}) which fulfills a suitable energy positivity condition with respect to a generator related with the cosmological time displacements. Furthermore {lambda} induces a preferred physically meaningful quantum state {lambda}{sub M} for the quantum theory in the bulk. If M admits a timelike Killing generator preserving J{sup -}, then the associated self-adjoint generator in the GNS representation of {lambda}{sub M} has positive spectrum (i.e. energy). Moreover {lambda}{sub M} turns out to be invariant under every symmetry of the bulk metric which preserves the cosmological horizon. In the case of an expanding de Sitter spacetime, {lambda}{sub M} coincides with the Euclidean (Bunch-Davies) vacuum state, hence being Hadamard in this case. Remarks on the validity of the Hadamard property for {lambda}{sub M} in more general spacetimes are presented. (orig.)
Tunneling from the past horizon
Kang, Subeom; Yeom, Dong-han
2018-04-01
We investigate a tunneling and emission process of a thin-shell from a Schwarzschild black hole, where the shell was initially located beyond the Einstein-Rosen bridge and finally appears at the right side of the Penrose diagram. In order to obtain such a solution, we should assume that the areal radius of the black hole horizon increases after the tunneling. Hence, there is a parameter range such that the tunneling rate is exponentially enhanced, rather than suppressed. We may have two interpretations regarding this. First, such a tunneling process from the past horizon is improbable by physical reasons; second, such a tunneling is possible in principle, but in order to obtain a stable Einstein-Rosen bridge, one needs to restrict the parameter spaces. If such a process is allowed, this can be a nonperturbative contribution to Einstein-Rosen bridges as well as eternal black holes.
Genesis of petroduric and petrocalcic horizons in Latinamerica volcanic soils
Quantin, Paul
2010-05-01
-arid climate. A complex soil profile of petrocalcic Phaeozem, derived from 4 pyroclastic layers, shows among its successive horizons: in layer 3 the 'upper cangahua' with petrocalcic features and in layer 4 the 'lower cangahua' with hard fragipan properties. The features of the petrocalcic cangahua differ from a Mexican fragipan (Hidalgo & al 1997) by: a hard calcrete, higher alkalinity, stability in water after HCl and NaOH treatment, 2-4% of 'free silica'. The macro and micro-morphology shows: the laminar calcite crust, at the top of cangahua, with alternate micrite-sparite layers; downwards, microcalcite infillings in the voids of a prismatic structure, invading the groundmass by epigenesis of clay sheets, together whith microcrystalline opal. From these data this scenario is inferred: after a former weathering of volcanic glass to form a clayey matrix, as well amorphous silica and microcalcite coatings and infillings, then a second process, perhaps due to drier climate, produced the laminar crust formation, by invasion of microcalcite in the matrix. Conclusion. The petrocalcic horizon in Ecuador was produced by two processes: from a former phase of weathering giving a fragic horizon to a second producing the accumulation of calcite and some opal over and inside the matrix, due to climate change. The petroduric horizon in Mexico, is the product of a very complex soil transformation, from a former clayey Nitisol, through four successive processes: clay eluviation-illuviation, alternate redoximorphy, clay degradation, finally a progressive silicification over and inside the groundmass, probably due to pedoclimate change. References F. Elsass, D. Dubroeucq & M. Thiry. 2000. Clay Minerals, 35, 477-489. C. Hidalgo, P. Quantin & F. Elsass. 1997. Memorias del III Simposio Internacional sobre Suelos volcanicos endurecidos (Quito 1996), p. 65-72. - P. Quantin & C. Zebrowski. 1997. idem, p. 29-47.- J.P. Rossignol & P. Quantin. 1997. idem, p. 73-82.
Losing Information Outside the Horizon
Directory of Open Access Journals (Sweden)
Samir D. Mathur
2015-06-01
Full Text Available Suppose we allow a system to fall freely from infinity to a point near (but not beyond the horizon of a black hole. We note that in a sense the information in the system is already lost to an observer at infinity. Once the system is too close to the horizon it does not have enough energy to send its information back because the information carrying quanta would get redshifted to a point where they get confused with Hawking radiation. If one attempts to turn the infalling system around and bring it back to infinity for observation then it will experience Unruh radiation from the required acceleration. This radiation can excite the bits in the system carrying the information, thus reducing the fidelity of this information. We find the radius where the information is essentially lost in this way, noting that this radius depends on the energy gap (and coupling of the system. We look for some universality by using the highly degenerate BPS ground states of a quantum gravity theory (string theory as our information storage device. For such systems one finds that the critical distance to the horizon set by Unruh radiation is the geometric mean of the black hole radius and the radius of the extremal hole with quantum numbers of the BPS bound state. Overall, the results suggest that information in gravity theories should be regarded not as a quantity contained in a system, but in terms of how much of this information is accessible to another observer.
Entropy of black holes with multiple horizons
Directory of Open Access Journals (Sweden)
Yun He
2018-05-01
Full Text Available We examine the entropy of black holes in de Sitter space and black holes surrounded by quintessence. These black holes have multiple horizons, including at least the black hole event horizon and a horizon outside it (cosmological horizon for de Sitter black holes and “quintessence horizon” for the black holes surrounded by quintessence. Based on the consideration that the two horizons are not independent each other, we conjecture that the total entropy of these black holes should not be simply the sum of entropies of the two horizons, but should have an extra term coming from the correlations between the two horizons. Different from our previous works, in this paper we consider the cosmological constant as the variable and employ an effective method to derive the explicit form of the entropy. We also try to discuss the thermodynamic stabilities of these black holes according to the entropy and the effective temperature.
Conformal Killing horizons and their thermodynamics
Nielsen, Alex B.; Shoom, Andrey A.
2018-05-01
Certain dynamical black hole solutions can be mapped to static spacetimes by conformal metric transformations. This mapping provides a physical link between the conformal Killing horizon of the dynamical black hole and the Killing horizon of the static spacetime. Using the Vaidya spacetime as an example, we show how this conformal relation can be used to derive thermodynamic properties of such dynamical black holes. Although these horizons are defined quasi-locally and can be located by local experiments, they are distinct from other popular notions of quasi-local horizons such as apparent horizons. Thus in the dynamical Vaidya spacetime describing constant accretion of null dust, the conformal Killing horizon, which is null by construction, is the natural horizon to describe the black hole.
Black Hole Horizons and Thermodynamics: A Quantum Approach
Directory of Open Access Journals (Sweden)
Nicola Pinamonti
2010-07-01
Full Text Available We focus on quantization of the metric of a black hole restricted to the Killing horizon with universal radius r0. After imposing spherical symmetry and after restriction to the Killing horizon, the metric is quantized employing the chiral currents formalism. Two "components of the metric" are indeed quantized: The former behaves as an affine scalar field under changes of coordinates, the latter is instead a proper scalar field. The action of the symplectic group on both fields is realized in terms of certain horizon diffeomorphisms. Depending on the choice of the vacuum state, such a representation is unitary. If the reference state of the scalar field is a coherent state rather than a vacuum, spontaneous breaking of conformal symmetry arises and the state contains a Bose-Einstein condensate. In this case the order parameter fixes the actual size of the black hole with respect to r0. Both the constructed state together with the one associated with the affine scalar are thermal states (KMS with respect to Schwarzschild Killing time when restricted to half horizon. The value of the order parameter fixes the temperature at the Hawking value as well. As a result, it is found that the quantum energy and entropy densities coincide with the black hole mass and entropy, provided the universal parameter r0 is suitably chosen, not depending on the size of the actual black hole in particular.
On black hole horizon fluctuations
International Nuclear Information System (INIS)
Tuchin, K.L.
1999-01-01
A study of the high angular momentum particles 'atmosphere' near the Schwarzschild black hole horizon suggested that strong gravitational interactions occur at invariant distance of the order of 3 √M [2]. We present a generalization of this result to the Kerr-Newman black hole case. It is shown that the larger charge and angular momentum black hole bears, the larger invariant distance at which strong gravitational interactions occur becomes. This invariant distance is of order 3 √((r + 2 )/((r + - r - ))). This implies that the Planckian structure of the Hawking radiation of extreme black holes is completely broken
End user programming with personally meaningful objects
CSIR Research Space (South Africa)
Smith, Andrew C
2016-09-01
Full Text Available (Kimchi et al., 2003). Perceptual organisation is a neuro-cognitive process that dictates how we perceive objects in physical space and how we interpret some objects as being distinct from others and yet other objects as part of a whole (Helm, 2014... called the designer-cum-user. Using this approach, the user creates a personally meaningful artefact that represents the target product. Although not confirmed, we anticipate that this approach reduces the initial cognitive load on the user when he uses...
Variable horizon in a peridynamic medium.
Energy Technology Data Exchange (ETDEWEB)
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.
Holography beyond the horizon and cosmic censorship
International Nuclear Information System (INIS)
Levi, Thomas S.; Ross, Simon F.
2003-01-01
We investigate the description of the region behind the event horizon in rotating black holes in the AdS conformal field theory correspondence, using the rotating Banados-Teitelboim-Zanelli black hole as a concrete example. We extend a technique introduced by Kraus, Ooguri, and Shenker, based on analytically continuing amplitudes defined in a Euclidean space, to include rotation. In the rotating case, boundary amplitudes again have two different bulk descriptions, involving either integration only over the regions outside the black holes' event horizon, or integration over this region and the region between the event horizon and the Cauchy horizon (inner horizon). We argue that generally, the holographic map will relate the field theory to the region bounded by the Cauchy horizons in spacetime. We also argue that these results suggest that the holographic description of black holes will satisfy strong cosmic censorship
Black hole versus cosmological horizon entropy
International Nuclear Information System (INIS)
Davis, Tamara M; Davies, P C W; Lineweaver, Charles H
2003-01-01
The generalized second law of thermodynamics states that entropy always increases when all event horizons are attributed with an entropy proportional to their area. We test the generalized second law by investigating the change in entropy when dust, radiation and black holes cross a cosmological event horizon. We generalize for flat, open and closed Friedmann-Robertson-Walker universes by using numerical calculations to determine the cosmological horizon evolution. In most cases, the loss of entropy from within the cosmological horizon is more than balanced by an increase in cosmological event horizon entropy, maintaining the validity of the generalized second law of thermodynamics. However, an intriguing set of open universe models shows an apparent entropy decrease when black holes disappear over the cosmological event horizon. We anticipate that this apparent violation of the generalized second law will disappear when solutions are available for black holes embedded in arbitrary backgrounds
Meaningful radiation worker training for temporary craftsmen
International Nuclear Information System (INIS)
Williams, S.L.
1976-01-01
The carefully organized Radiation Worker Training Program presented to permanently assigned personnel at a power reactor facility too often falls by the wayside when temporary craftsmen are brought in for an outage. Even though these temporary workers will frequently be assigned to outage jobs with high radiation and/or contamination exposures, their Radiation Worker Training is often squeezed into an already busy schedule, thus reducing its effectiveness. As an aid for evaluating the effectiveness of an existing Radiation Worker Training Program for temporary craftsmen or for setting up a new program, the following guides are presented and discussed in this paper: the training environment; the interest and meaningfulness of the presentation; the method or methods used for presentation of the training information; the use of demonstrations; trainee participation; and, measuring the amount and type of information retained by a trainee. Meaningful Radiation Worker Training for temporary craftsmen can pay big dividends. Craftsmen can be expected to make fewer mistakes, thus reducing radiation exposure and lessening the chance for the spread of contamination. The craftsmen will also benefit by being able to work longer and utility management will benefit by having lower outage costs
Cartan invariants and event horizon detection
Brooks, D.; Chavy-Waddy, P. C.; Coley, A. A.; Forget, A.; Gregoris, D.; MacCallum, M. A. H.; McNutt, D. D.
2018-04-01
We show that it is possible to locate the event horizon of a black hole (in arbitrary dimensions) by the zeros of certain Cartan invariants. This approach accounts for the recent results on the detection of stationary horizons using scalar polynomial curvature invariants, and improves upon them since the proposed method is computationally less expensive. As an application, we produce Cartan invariants that locate the event horizons for various exact four-dimensional and five-dimensional stationary, asymptotically flat (or (anti) de Sitter), black hole solutions and compare the Cartan invariants with the corresponding scalar curvature invariants that detect the event horizon.
The Retention of Meaningful Understanding of Meiosis and Genetics.
Cavallo, Ann Liberatore
This study investigated the retention of meaningful understanding of the biological topics of meiosis, the Punnett square method and the relations between these two topics. This study also explored the predictive influence of students' general tendency to learn meaningfully or by rote (meaningful learning orientation), prior knowledge of meiosis,…
Towards a mathematical theory of meaningful communication
Corominas-Murtra, Bernat; Fortuny, Jordi; Solé, Ricard V.
2014-04-01
Meaning has been left outside most theoretical approaches to information in biology. Functional responses based on an appropriate interpretation of signals have been replaced by a probabilistic description of correlations between emitted and received symbols. This assumption leads to potential paradoxes, such as the presence of a maximum information associated to a channel that creates completely wrong interpretations of the signals. Game-theoretic models of language evolution and other studies considering embodied communicating agents show that the correct (meaningful) match resulting from agent-agent exchanges is always achieved and natural systems obviously solve the problem correctly. Inspired by the concept of duality of the communicative sign stated by the swiss linguist Ferdinand de Saussure, here we present a complete description of the minimal system necessary to measure the amount of information that is consistently decoded. Several consequences of our developments are investigated, such as the uselessness of a certain amount of information properly transmitted for communication among autonomous agents.
The challenge of a meaningful job
DEFF Research Database (Denmark)
Jepsen, Ingrid
and the feeling of doing high quality care generate job satisfaction. The obligation and pressure to perform well and the disadvantages on the midwives’ private lives is counterbalanced by the feeling of doing a meaningful and important job. Working in caseload midwifery creates a feeling of working in a self....... The methodology was inspired by ethnography, and applied methods were field observations followed by interviews. Participants: Thirteen out of eighteen midwives working in caseloads were observed during one or two days in the antenatal clinic and interviewed at a later occasion. Findings: The recognition......-governing model within the public hospital, without losing the technological benefits of a modern birth unit. For pregnant women with a challenging personality or attitude towards others, Caseload midwifery may provide an extra opportunity to feel recognized and respected. Key conclusions: Caseload midwifery...
Creating Visual Design and Meaningful Audience Experiences
DEFF Research Database (Denmark)
Steijn, Arthur; Ion Wille, Jakob
2014-01-01
The main purpose of the EU Interreg funded Classical Composition Music and Experience Design project, was to rethink audience experiences and develop knowledge of applied technologies connected to classical music and live concerts. The project and its main objectives was motivated by at least thee...... conditions. The most important being 1) the development in new technology creating new expectations in audiences attending cultural events, including classical concerts, 2) resent decline in audiences attending classical music and 3) a will to strengthen relations between cultural institutions, creative...... businesses and educational institutions in the Øresund region (including the city and surroundings of Malmø and Copenhagen). Therefore the project Classical Composition Music and Experience Design focused on developing new and meaningful audience experiences where live classical music meets new digital...
Meaningful Academic Work as Praxis in Emergence
Directory of Open Access Journals (Sweden)
Keijo Räsänen
2008-01-01
Full Text Available The managerial form of university governance has changed the conditions of academic work in many countries. While some academics consider this a welcome development, others experience it as a threat to their autonomy and to the meaningfulness of their work. This essay suggests a stance in response to the current conditions that should serve especially the latter group of academics. The claim is that by approaching academic work as a potential praxis in emergence, it is possible to appreciate local, autonomous activity in renewing academic work. Even if such efforts remain difficult, dispersed in space, discontinuous in time, and incomplete, they may provide a sense of direction and keep up hope. The conception of praxis is a way of articulating the mission of such efforts; simultaneously, it is also a way of defining an epistemic object for research on academic work.
WHATSAPP CONTRIBUTIONS IN SPANISH TEACHING: A PERSPECTIVE OF MEANINGFUL AND COLLABORATIVE LEARNING
Directory of Open Access Journals (Sweden)
Iandra Maria Weirich da Silva Coelho
2017-08-01
Full Text Available This article describes a didactic proposal, mediated by the use of WhatsApp as a potential tool for the teaching of Spanish as an additional language. Activities are drawn from collaborative and meaningful practice with authentic situations of the language usage, taking by reference the theoretical construct of the Theory of Meaningful Learning (AUSUBEL, 2003 and Collaborative Practice of Writing. The results identify positive contributions about the increased interest and motivation of students, promotion of discursive competence, interactivity, autonomy, about actions involving the authorship and collaborative construction in information network for knowledge sharing.
Competition, Time Horizon and Corporate Social Performance
Graafland, J.J.; Smid, H.
2013-01-01
Abstract: This paper develops and tests a conceptual framework on the relationships between competition, time horizon and corporate social performance (CSP). We hypothesize that more intense competition discourages CSP by lowering the time horizon of companies. We test the hypothesis on a sample of
The NMC Horizon Report: 2015 Museum Edition
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…
Maximal indecomposable past sets and event horizons
International Nuclear Information System (INIS)
Krolak, A.
1984-01-01
The existence of maximal indecomposable past sets MIPs is demonstrated using the Kuratowski-Zorn lemma. A criterion for the existence of an absolute event horizon in space-time is given in terms of MIPs and a relation to black hole event horizon is shown. (author)
Novak, Joseph D.
2002-07-01
The construction and reconstruction of meanings by learners requires that they actively seek to integrate new knowledge with knowledge already in their cognitive structure. Ausubel's assimilation theory of cognitive learning has been shown to be effective in guiding research and instructional design to facilitate meaningful learning (Ausubel, The psychology of meaningful verbal learning, New York: Grune and Stratton, 1963; Educational psychology: A cognitive view, New York: Holt, Rinehart and Winston, 1968; The acquisition and retention of knowledge, Dordrecht: Kluwer, 2000). Gowin's Vee heuristic has been employed effectively to aid teachers and students in understanding the constructed nature of knowledge (Gowin, Educating, Ithaca, NY: Cornell University Press, 1981). Situated learning occurs when learning is by rote or at a lower level of meaningful learning. Concept mapping has been used effectively to aid meaningful learning with resulting modification of student's knowledge structures. When these knowledge structures are limited or faulty in some way, they may be referred to as Limited or Inappropriate Propositional Hierarchies (LIPH's). Conceptual change, or more accurately conceptual reconstrution, requires meaningful learning to modify LIPH's. Collaborative group learning facilitates meaningful learning and new knowledge construction. World-wide economic changes are forcing major changes in business and industry placing a premium on the power and value of knowledge and new knowledge production. These changes require changes in school and university education that centers on the nature and power of meaningful learning. New computer tools are available to facilitate teaching activities targeted at modifying LIPH's, and aiding meaningful learning in general.
Thermodynamics of the Apparent Horizon in FRW Universe with Massive Gravity
International Nuclear Information System (INIS)
Li Hui; Zhang Yi
2013-01-01
Applying Clausius relation with energy-supply defined by the unified first law of thermodynamics formalism to the apparent horizon of a massive gravity model in cosmology proposed lately, the corrected entropic formula of the apparent horizon is obtained with the help of the modified Friedmann equations. This entropy-area relation, together with the identified Misner-Sharp internal energy, verifies the first law of thermodynamics for the apparent horizon with a volume change term for consistency. On the other hand, by means of the corrected entropy-area formula and the Clausius relation δQ = T d S, where the heat Bow δQ is the energy-supply of pure matter projecting on the vector ξ tangent to the apparent horizon and should be looked on as the amount of energy crossing the apparent horizon during the time interval dt and the temperature of the apparent horizon for energy crossing during the same interval is 1/(2πr A ), the modified Friedmann equations governing the dynamical evolution of the universe are reproduced with the known energy density and pressure of massive graviton. The integration constant is found to correspond to a cosmological term which could be absorbed into the energy density of matter. Having established the correspondence of massive cosmology with the unified first law of thermodynamics on the apparent horizon, the validity of the generalized second law of thermodynamics is also discussed by assuming the thermal equilibrium between the apparent horizon and the matter field bounded by the apparent horizon. It is found that, in the limit H c → 0, which recovers the Minkowski reference metric solution in the fiat case, the generalized second law of thermodynamics holds if α 3 + 4α 4 3 = α 4 = 0, the generalized second law of thermodynamics could be violated. (general)
Motivational reading on education, meaningful reading realisation
Directory of Open Access Journals (Sweden)
Adriana Qafa
2017-07-01
Full Text Available In this study I will present some ideas on today’s educational practice for motivation, the realization of the meaningful reading. There is a special place for the methodical ranking of the reading process, starting in school. Main requests of this reading, consist of the deep meaning of the subject, exploration of the idea, and other elements of the subject, implementation of the technique’s rules of the expressive reading, such as breathing, voice, diction, intonation, spelling, stoppages, logical emphasizes, emotional expressions, temper, timber, gesticulations, and mimic. There is also highlighted the fact that the used method comes from the pupils’ results and depends on the capability and level of the teacher, from the programming’s scale, the tools that are put into disposition, the age and the level of the pupils, and from the environment that the teacher creates during courses. At the end there are some practical guidelines for the realization of the expressive reading in the literature subject.
Symmetries of cosmological Cauchy horizons
International Nuclear Information System (INIS)
Moncrief, V.; Isenberg, J.
1983-01-01
We consider analytic vacuum and electrovacuum spacetimes which contain a compact null hypersurface ruled by closed null generators. We prove that each such spacetime has a non-trivial Killing symmetry. We distinguish two classes of null surfaces, degenerate and non-degenerate ones, characterized by the zero or non-zero value of a constant analogous to the ''surface gravity'' of stationary black holes. We show that the non-degenerate null surfaces are always Cauchy heizons across which the Killing fields change from spacelike (in the globally hyperbolic regions) to timelike (in the acausal, analytic extensions). For the special case of a null surface diffeomorphic to T 3 we characterize the degenerate vacuum solutions completely. These consists of an infinite dimensional family of ''plane wave'' spacetimes which are entirely foliated by compact null surfaces. Previous work by one of us has shown that, when one dimensional Killing symmetries are allowed, then infinite dimensional families of non-degenerate, vacuum solutions exist. We recall these results for the case of Cauchy horizons diffeomorphic to T 3 and prove the generality of the previously constructed non-degenerate solutions. We briefly discuss the possibility of removing the assumptions of closed generators and analyticity and proving an appropriate generalization of our main results. Such a generalization would provide strong support for the cosmic censorship conjecture by showing that causality violating, cosmological solutions of Einstein's equations are essentially an artefact of symmetry. (orig.)
Dynamical symmetry enhancement near IIA horizons
International Nuclear Information System (INIS)
Gran, University; Gutowski, J.; Kayani, University; Papadopoulos, G.
2015-01-01
We show that smooth type IIA Killing horizons with compact spatial sections preserve an even number of supersymmetries, and that the symmetry algebra of horizons with non-trivial fluxes includes an sl(2,ℝ) subalgebra. This confirms the conjecture of http://dx.doi.org/10.1007/JHEP11(2013)104 for type IIA horizons. As an intermediate step in the proof, we also demonstrate new Lichnerowicz type theorems for spin bundle connections whose holonomy is contained in a general linear group.
Across-horizon scattering and information transfer
Emelyanov, V. A.; Klinkhamer, F. R.
2018-06-01
We address the question whether or not two electrically charged elementary particles can Coulomb scatter if one of these particles is inside the Schwarzschild black-hole horizon and the other outside. It can be shown that the quantum process is consistent with the local energy–momentum conservation law. This result implies that across-horizon scattering is a physical effect, relevant to astrophysical black holes. We propose a Gedankenexperiment which uses the quantum scattering process to transfer information from inside the black-hole horizon to outside.
Horizon quantum mechanics of rotating black holes
Energy Technology Data Exchange (ETDEWEB)
Casadio, Roberto [Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (Italy); I.N.F.N., Sezione di Bologna, I.S. FLAG, Bologna (Italy); Giugno, Andrea [Ludwig-Maximilians-Universitaet, Arnold Sommerfeld Center, Munich (Germany); Giusti, Andrea [Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (Italy); I.N.F.N., Sezione di Bologna, I.S. FLAG, Bologna (Italy); Ludwig-Maximilians-Universitaet, Arnold Sommerfeld Center, Munich (Germany); Micu, Octavian [Institute of Space Science, Bucharest, P.O. Box MG-23, Bucharest-Magurele (Romania)
2017-05-15
The horizon quantum mechanics is an approach that was previously introduced in order to analyze the gravitational radius of spherically symmetric systems and compute the probability that a given quantum state is a black hole. In this work, we first extend the formalism to general space-times with asymptotic (ADM) mass and angular momentum. We then apply the extended horizon quantum mechanics to a harmonic model of rotating corpuscular black holes. We find that simple configurations of this model naturally suppress the appearance of the inner horizon and seem to disfavor extremal (macroscopic) geometries. (orig.)
Black hole entropy, universality, and horizon constraints
International Nuclear Information System (INIS)
Carlip, Steven
2006-01-01
To ask a question about a black hole in quantum gravity, one must restrict initial or boundary data to ensure that a black hole is actually present. For two-dimensional dilaton gravity, and probably a much wider class of theories, I show that the imposition of a 'stretched horizon' constraint modifies the algebra of symmetries at the horizon, allowing the use of conformal field theory techniques to determine the asymptotic density of states. The result reproduces the Bekenstein-Hawking entropy without any need for detailed assumptions about the microscopic theory. Horizon symmetries may thus offer an answer to the problem of universality of black hole entropy
Black hole entropy, universality, and horizon constraints
Energy Technology Data Exchange (ETDEWEB)
Carlip, Steven [Department of Physics, University of California, Davis, CA 95616 (United States)
2006-03-01
To ask a question about a black hole in quantum gravity, one must restrict initial or boundary data to ensure that a black hole is actually present. For two-dimensional dilaton gravity, and probably a much wider class of theories, I show that the imposition of a 'stretched horizon' constraint modifies the algebra of symmetries at the horizon, allowing the use of conformal field theory techniques to determine the asymptotic density of states. The result reproduces the Bekenstein-Hawking entropy without any need for detailed assumptions about the microscopic theory. Horizon symmetries may thus offer an answer to the problem of universality of black hole entropy.
Tropospheric radiowave propagation beyond the horizon
Du Castel, François
1966-01-01
Tropospheric Radiowave Propagation Beyond the Horizon deals with developments concerning the tropospheric propagation of ultra-short radio waves beyond the horizon, with emphasis on the relationship between the theoretical and the experimental. Topics covered include the general conditions of propagation in the troposphere; general characteristics of propagation beyond the horizon; and attenuation in propagation. This volume is comprised of six chapters and begins with a brief historical look at the various stages that have brought the technique of transhorizon links to its state of developmen
Stretched horizons, quasiparticles, and quasinormal modes
International Nuclear Information System (INIS)
Iizuka, Norihiro; Kabat, Daniel; Lifschytz, Gilad; Lowe, David A.
2003-01-01
We propose that stretched horizons can be described in terms of a gas of noninteracting quasiparticles. The quasiparticles are unstable, with a lifetime set by the imaginary part of the lowest quasinormal mode frequency. If the horizon arises from an AdS-CFT style duality the quasiparticles are also the effective low-energy degrees of freedom of the finite-temperature CFT. We analyze a large class of models including Schwarzschild black holes, nonextremal Dp-branes, the rotating BTZ black hole and de Sitter space, and we comment on degenerate horizons. The quasiparticle description makes manifest the relationship between entropy and area
Implementing VMware Horizon View 5.2
Ventresco, Jason
2013-01-01
A step-by-step tutorial covering all components of the View Horizon suite in detail, to ensure that you can utilize all features of the platform, and discover all of the possible ways that it can be used within your own environment.If you are a newcomer in system administration, and you wish to implement a small to midsized Horizon View environment, then this book is for you. It will also benefit individuals who wish to administrate and manage Horizon View more efficiently or are studying for the VCP5-DT.
Directory of Open Access Journals (Sweden)
Martin Sedlár
2014-01-01
satisfaction with life. Correlation coeficients of these relations showed that flow experience is relatively equally associated with life meaningfulness and subjective well–being. It suggests that flow experience is partly hedonic and also eudaimonic concept. Next, all dimensions of life meaningfulness correlate positively with positive affectivity and satisfaction with life, and negatively with negative affectivity. Multiple regression analysis revealed that life meaningfulness significantly contributes to all components of subjective well–being, and experiencing flow significantly predicts only negative affectivity. Thus, life meaningfulness brings good feeling and creates in one‘smind order just like flow does it on its own way and in shorter time period. Flow experience rather prevents experiencing unpleasant affects. Considering specific research sample, generalizations of the results are limited. This is quantitative research which does not enable to examine phenomenological nuances of flow experience that are usually examined. Qualitative research, but also personality characteristics, age of musicians and length of musical practise would give another view on examined relations. Despite some limitations, our results confirm theoretical assumptions and research studies. They refer to the function of flow experience in musical activity and especially to life meaningfulness as important factor of subjective well–being.
Reference costs of electricity
International Nuclear Information System (INIS)
Terraz, N.
1997-01-01
The calculation of electric power production reference costs is used in France, even in the present case of over-capacity, for comparing the relative interest of the various means of power generation (nuclear plants, coal plants, hydroelectricity, gas combined cycles, etc.) and as an aid for future investment decisions. Reference costs show a sharp decrease between 1993 and 1997 due to advancements in nuclear plant operating ability and fossil fuel price decrease. Actuarial rates, plant service life, fuel costs and exchange rates are important parameters. The various costs from the research stage to the waste processing stages are discussed and the reference costs of the various power generation systems are presented and compared together with their competitiveness; the future of wind energy and cogeneration and the prospective of the renewal of nuclear plants at the 2010 horizon are also addressed
Gifted-Child Pedagogy: Meaningful Chimera?
Coleman, Laurence J.
2003-01-01
This article explores the concept of gifted-child pedagogy (GCP) and consequences of adopting a GCP model. It argues that use of the term GCP can create a faux reality that GCP exists and that teachers who do not have this particular pedagogy cannot help gifted children. (Contains 7 references.) (CR)
Meaningful Professional Development: A Personal Journey
Shore, Rebecca Ann
2012-01-01
This article shares a personal story of the evolution of professional development in practice in K-12 schools from three states over a 30 year period. The article begins with reference to general subject area life awarded teaching credentials and concludes with the addition of language addressing prekindergarten, specifically the inclusion of…
A meaningful MESS (Medical Education Scholarship Support
Directory of Open Access Journals (Sweden)
Shari A. Whicker
2016-07-01
Full Text Available Background: Graduate medical education faculty bear the responsibility of demonstrating active research and scholarship; however, faculty who choose education-focused careers may face unique obstacles related to the lack of promotion tracks, funding, career options, and research opportunities. Our objective was to address education research and scholarship barriers by providing a collaborative peer-mentoring environment and improve the production of research and scholarly outputs. Methods: We describe a Medical Education Scholarship Support (MESS group created in 2013. MESS is an interprofessional, multidisciplinary peer-mentoring education research community that now spans multiple institutions. This group meets monthly to address education research and scholarship challenges. Through this process, we develop new knowledge, research, and scholarly products, in addition to meaningful collaborations. Results: MESS originated with eight founding members, all of whom still actively participate. MESS has proven to be a sustainable unfunded local community of practice, encouraging faculty to pursue health professions education (HPE careers and fostering scholarship. We have met our original objectives that involved maintaining 100% participant retention; developing increased knowledge in at least seven content areas; and contributing to the development of 13 peer-reviewed publications, eight professional presentations, one Masters of Education project, and one educational curriculum. Discussion: The number of individuals engaged in HPE research continues to rise. The MESS model could be adapted for use at other institutions, thereby reducing barriers HPE researchers face, providing an effective framework for trainees interested in education-focused careers, and having a broader impact on the education research landscape.
« To see beyond the horizon of mere selfishness » : l’horizon moral dans les romans de George Eliot
Toussaint, Benjamine
2015-01-01
In spite of her apostasy, George Eliot still believed in the moral and spiritual values of Christianity and it is hardly surprising she should have used the metaphor of the horizon to refer to this ideal notion of the essence of Christianity since the horizon is both unreachable and yet always visible, showing the direction one ought to follow. Her characters’ moral odyssey is about learning to see beyond the limits of their own self-centered experience; however, as Lydgate underlines in Midd...
Horizon Entropy from Quantum Gravity Condensates.
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.
Nonlinear optics of fibre event horizons.
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.
Deepwater Horizon Seafood Safety Oracle Database (2010)
National Oceanic and Atmospheric Administration, Department of Commerce — In 2010, the Deepwater Horizon oil spill occurred in the Gulf of Mexico. In response to this spill, the National Marine Fisheries Service initiated a data collection...
Deep Water Horizon (HB1006, EK60)
National Oceanic and Atmospheric Administration, Department of Commerce — Monitor and measure the biological, chemical, and physical environment in the area of the oil spill from the deep water horizon oil rig in the Gulf of Mexico. A wide...
Subjective Life Horizon and Portfolio Choice
Spaenjers , Christophe; Spira, Sven Michael
2013-01-01
Using data from a U.S. household survey, we examine the empirical relation between subjective life horizon (i.e., the self-reported expectation of remaining life span) and portfolio choice. We find that equity portfolio shares are higher for investors with longer horizons, ceteris paribus, in line with theoretical predictions. This result is robust to controlling for optimism and health status, accounting for the endogeneity of equity market participation, or instrumenting subjective life hor...
VMware Horizon View 6 desktop virtualization cookbook
Ventresco, Jason
2014-01-01
If you want a more detailed explanation concerning the implementation of several different core features of VMware Horizon View, this is the book for you. Whether you are new to VMware Horizon View or an existing user, this book will provide you with the knowledge you need to successfully deploy several core features and get introduced to the latest features of version 6.0 as well.
Are students ready for meaningful use?
Directory of Open Access Journals (Sweden)
Gary S. Ferenchick
2013-11-01
Full Text Available Background: The meaningful use (MU of electronic medical records (EMRs is being implemented in three stages. Key objectives of stage one include electronic analysis of data entered into structured fields, using decision-support tools (e.g., checking drug–drug interactions [DDI] and electronic information exchange. Objective: The authors assessed the performance of medical students on 10 stage-one MU tasks and measured the correlation between students’ MU performance and subsequent end-of-clerkship professionalism assessments and their grades on an end-of-year objective structured clinical examination. Participants: Two-hundred and twenty-two third-year medical students on the internal medicine (IM clerkship. Design/main measures: From July 2010 to February 2012, all students viewed 15 online tutorials covering MU competencies. The authors measured student MU documentation and performance in the chart of a virtual patient using a fully functional training EMR. Specific MU measurements included, adding: a new problem, a new medication, an advanced directive, smoking status, the results of screening tests; and performing a DDI (in which a major interaction was probable, and communicating a plan for this interaction. Key results: A total of 130 MU errors were identified. Sixty-eight (30.6% students had at least one error, and 30 (13.5% had more than one (range 2–6. Of the 130 errors, 90 (69.2% were errors in structured data entry. Errors occurred in medication dosing and instructions (18%, DDI identification (12%, documenting smoking status (15%, and colonoscopy results (23%. Students with MU errors demonstrated poorer performance on end-of-clerkship professionalism assessments (r=−0.112, p=0.048 and lower observed structured clinical examination (OSCE history-taking skills (r=−0.165, p=0.008 and communication scores (r=− 0.173, p=0.006. Conclusions: MU errors among medical students are common and correlate with subsequent poor
Cosmological event horizons, thermodynamics, and particle creation
International Nuclear Information System (INIS)
Gibbons, G.W.; Hawking, S.W.
1977-01-01
It is shown that the close connection between event horizons and thermodynamics which has been found in the case of black holes can be extended to cosmological models with a repulsive cosmological constant. An observer in these models will have an event horizon whose area can be interpreted as the entropy or lack of information of the observer about the regions which he cannot see. Associated with the event horizon is a surface gravity kappa which enters a classical ''first law of event horizons'' in a manner similar to that in which temperature occurs in the first law of thermodynamics. It is shown that this similarity is more than an analogy: An observer with a particle detector will indeed observe a background of thermal radiation coming apparently from the cosmological event horizon. If the observer absorbs some of this radiation, he will gain energy and entropy at the expense of the region beyond his ken and the event horizon will shrink. The derivation of these results involves abandoning the idea that particles should be defined in an observer-independent manner. They also suggest that one has to use something like the Everett-Wheeler interpretation of quantum mechanics because the back reaction and hence the spacetime metric itself appear to be observer-dependent, if one assumes, as seems reasonable, that the detection of a particle is accompanied by a change in the gravitational field
Horizons of hermeneutics: Intercultural hermeneutics in a globalizing world
J. de Mul (Jos)
2011-01-01
textabstractStarting from the often-used metaphor of the "horizon of experience" this article discusses three different types of intercultural hermeneutics, which respectively conceive hermeneutic interpretation as a widening of horizons, a fusion of horizons, and a dissemination of horizons. It is
Meaningfulness of Service and Marital Satisfaction in Army Couples
Bergmann, Jeffrey S.; Renshaw, Keith D.; Allen, Elizabeth S.; Markman, Howard J.; Stanley, Scott M.
2015-01-01
The vast numbers of military service members who have been deployed since 2001 highlights the need to better understand relationships of military couples. A unique consideration in military couples is the concept of meaningfulness of service, or the value service members and their partners place on military service in spite of the sacrifices it requires. In a sample of 606 Army couples, we used path analysis to examine how male service members’ and female spouses’ perceived meaningfulness of service added to the prediction of marital satisfaction in both members of the couple, when accounting for service members’ PTSD symptoms. Spouses’ perceived meaningfulness of service was linked with higher marital satisfaction in spouses, regardless of service member’s perceived meaningfulness of service. Service members’ perceived meaningfulness of service was also associated with increased marital satisfaction in service members, but only when their spouses also perceived higher meaningfulness. There were no significant interactions between service members’ PTSD and either partner’s perceived meaningfulness. Implications for enhanced attention to spousal perceptions of meaningfulness of service are discussed. PMID:25046347
Intrinsic Value and a Meaningful Life | Audi | Philosophical Papers
African Journals Online (AJOL)
I distinguish various ways in which human life may be thought to be meaningful and present an account of what might be called existential meaningfulness. The account is neutral with respect to both theism and naturalism, but each is addressed in several places and the paper's main points are harmonious with certain ...
Meaningfulness of service and marital satisfaction in Army couples.
Bergmann, Jeffrey S; Renshaw, Keith D; Allen, Elizabeth S; Markman, Howard J; Stanley, Scott M
2014-10-01
The vast numbers of military service members who have been deployed since 2001 highlights the need to better understand relationships of military couples. A unique consideration in military couples is the concept of meaningfulness of service, or the value service members and their partners place on military service in spite of the sacrifices it requires. In a sample of 606 Army couples, the authors used path analysis to examine how male service members' and female spouses' perceived meaningfulness of service added to the prediction of marital satisfaction in both members of the couple, when accounting for service members' PTSD symptoms. Spouses' perceived meaningfulness of service was linked with higher marital satisfaction in spouses, regardless of service member's perceived meaningfulness of service. Service members' perceived meaningfulness of service was also associated with increased marital satisfaction in service members, but only when their spouses also perceived higher meaningfulness. There were no significant interactions between service members' PTSD and either partner's perceived meaningfulness. Implications for enhanced attention to spousal perceptions of meaningfulness of service are discussed. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
Meaningful Use of Health Information Technology by Rural Hospitals
McCullough, Jeffrey; Casey, Michelle; Moscovice, Ira; Burlew, Michele
2011-01-01
Purpose: This study examines the current status of meaningful use of health information technology (IT) in Critical Access Hospitals (CAHs), other rural, and urban US hospitals, and it discusses the potential role of Medicare payment incentives and disincentives in encouraging CAHs and other rural hospitals to achieve meaningful use. Methods: Data…
Characteristics of meaningful chemistry education - The case of water quality
Westbroek, Hanna Barbara
2005-01-01
This thesis addresses the question of how to involve students in meaningful chemistry education by a proper implementation of three characteristics of meaningful: a context, a need-to-know approach and attention for student input. The characteristics were adopted as solution strategies for
Relationship between meaningful work and job performance in nurses.
Tong, Ling
2018-04-01
The present study was designed to determine the relationship between meaningful work and job performance, and the impact of meaningful work on nursing care quality. Meaningful work has been suggested as a significant factor affecting job performance, but the relationship has never been studied in nurses in China. A descriptive correlational study was designed to assess the level of meaningful work, tasks, and contextual performance as well as their relationships. We used a stratified random-sampling approach to enrol nurses from hospitals. Multivariate regression analysis was applied to determine the relationship between meaningful work and their demographic data. There were significant, positive relationships between meaningful work and task performance and contextual performance. Education level, work unit, and employment type influenced meaningful work. The work motivation score of the nurses was lower than that of the other 2 dimensions, and a negative work motivation score negatively influenced job performance. Improving meaningful work and providing more support and assistance could improve nurse performance, thereby improving the quality of nursing care. © 2018 John Wiley & Sons Australia, Ltd.
Self-Determination and Meaningful Work: Exploring Socioeconomic Constraints
Directory of Open Access Journals (Sweden)
Blake A Allan
2016-02-01
Full Text Available This study examined a model of meaningful work among a diverse sample of working adults. From the perspectives of Self-Determination Theory and the Psychology of Working Framework, we tested a structural model with social class and work volition predicting SDT motivation variables, which in turn predicted meaningful work. Partially supporting hypotheses, work volition was positively related to internal regulation and negatively related to amotivation, whereas social class was positively related to external regulation and amotivation. In turn, internal regulation was positively related to meaningful work, whereas external regulation and amotivation were negatively related to meaningful work. Indirect effects from work volition to meaningful work via internal regulation and amotivation were significant, and indirect effects from social class to meaningful work via external regulation and amotivaiton were significant. This study highlights the important relations between SDT motivation variables and meaningful work, especially the large positive relation between internal regulation and meaningful work. However, results also reveal that work volition and social class may play critical roles in predicting internal regulation, external regulation, and amotivation.
Self-Determination and Meaningful Work: Exploring Socioeconomic Constraints.
Allan, Blake A; Autin, Kelsey L; Duffy, Ryan D
2016-01-01
This study examined a model of meaningful work among a diverse sample of working adults. From the perspectives of Self-Determination Theory and the Psychology of Working Framework, we tested a structural model with social class and work volition predicting SDT motivation variables, which in turn predicted meaningful work. Partially supporting hypotheses, work volition was positively related to internal regulation and negatively related to amotivation, whereas social class was positively related to external regulation and amotivation. In turn, internal regulation was positively related to meaningful work, whereas external regulation and amotivation were negatively related to meaningful work. Indirect effects from work volition to meaningful work via internal regulation and amotivation were significant, and indirect effects from social class to meaningful work via external regulation and amotivation were significant. This study highlights the important relations between SDT motivation variables and meaningful work, especially the large positive relation between internal regulation and meaningful work. However, results also reveal that work volition and social class may play critical roles in predicting internal regulation, external regulation, and amotivation.
Meaningful work and secondary school teachers' intention to leave ...
African Journals Online (AJOL)
The following measuring instruments were used: Work-role Fit Scale, Job Enrichment Scale, Co-worker and Supervisor Relationships Scales, Psychological Meaningfulness Scale and Turnover Intention Scale. Work-role fit and job enrichment both had direct positive effect on experiences of psychological meaningfulness at ...
Between order and chaos: The quest for meaningful information
Adriaans, P.
2009-01-01
The notion of meaningful information seems to be associated with the sweet spot between order and chaos. This form of meaningfulness of information, which is primarily what science is interested in, is not captured by both Shannon information and Kolmogorov complexity. In this paper I develop a
Meaningful spatial and temporal sequences of activities in dwelling
Hematalikeikha, M.A.; Coolen, H.C.C.H.; Pourdeihimi, S.
2014-01-01
Human activities based on human needs are affected by affordances and meanings that occur in the dwelling. Activities over time and space have meaningful sequences. The meaningfulness of activities in the cultural framework is conditioned by its special temporality and spatiality. Also, temporal or
Meaningful work and secondary school teachers' intention to leave
Directory of Open Access Journals (Sweden)
M. Janik
2015-05-01
Full Text Available The study investigates the relations between secondary school teachers' work-role fit, job enrichment, supervisor relationships, co-worker relationships, psychological meaningfulness of work and intention to leave. A cross-sectional survey was used. The participants were 502 secondary school teachers in Namibia. The following measuring instruments were used: Work-role Fit Scale, Job Enrichment Scale, Co-worker and Supervisor Relationships Scales, Psychological Meaningfulness Scale and Turnover Intention Scale. Work-role fit and job enrichment both had direct positive effect on experiences of psychological meaningfulness at work, while poor work-role fit and low psychological meaningfulness both had a direct effect on teachers' intentions to leave. An analysis of the indirect effects showed that poor work-role fit and poor job enrichment affected intention to leave due to the concomitant experience of low psychological meaningfulness. These findings have implications for the retention of teachers in secondary schools.
ON THE DERIVATIVE OF SMOOTH MEANINGFUL FUNCTIONS
Directory of Open Access Journals (Sweden)
Sanjo Zlobec
2011-02-01
Full Text Available The derivative of a function f in n variables at a point x* is one of the most important tools in mathematical modelling. If this object exists, it is represented by the row n-tuple f(x* = [∂f/∂xi(x*] called the gradient of f at x*, abbreviated: “the gradient”. The evaluation of f(x* is usually done in two stages, first by calculating the n partials and then their values at x = x*. In this talk we give an alternative approach. We show that one can characterize the gradient without differentiation! The idea is to fix an arbitrary row n-tuple G and answer the following question: What is a necessary and sufficient condition such that G is the gradient of a given f at a given x*? The answer is given after adjusting the quadratic envelope property introduced in [3]. We work with smooth, i.e., continuously differentiable, functions with a Lipschitz derivative on a compact convex set with a non-empty interior. Working with this class of functions is not a serious restriction. In fact, loosely speaking, “almost all” smooth meaningful functions used in modelling of real life situations are expected to have a bounded “acceleration” hence they belong to this class. In particular, the class contains all twice differentiable functions [1]. An important property of the functions from this class is that every f can be represented as the difference of some convex function and a convex quadratic function. This decomposition was used in [3] to characterize the zero derivative points. There we obtained reformulations and augmentations of some well known classic results on optimality such as Fermats extreme value theorem (known from high school and the Lagrange multiplier theorem from calculus [2, 3]. In this talk we extend the results on zero derivative points to characterize the relation G = f(x*, where G is an arbitrary n-tuple. Some special cases: If G = O, we recover the results on zero derivative points. For functions of a single
Sacrifice: an ethical dimension of caring that makes suffering meaningful.
Helin, Kaija; Lindström, Unni A
2003-07-01
This article is intended to raise the question of whether sacrifice can be regarded stituting a deep ethical structure in the relationship between patient and carer. The significance of sacrifice in a patient-carer relationship cannot, however, be fully understood from the standpoint of the consistently utilitarian ethic that characterizes today's ethical discourse. Deontological ethics, with its universal principles, also does not provide a suitable point of departure. Ethical recommendations and codices are important and serve as general sources of knowledge when making decisions, but they should be supplemented by an ethic that takes into consideration contextual and situational factors that make every encounter between patient and carer unique. Caring science research literature presents, on the whole, general agreement on the importance of responsibility and devotian with regard to sense of duty, warmth and genuine engagement in caring. That sacrifice may also constitute an important ethical element in the patient-carer relationship is, however, a contradictory and little considered theme. Caring literature that deals with sacrifice/self-sacrifice indicates contradictory import. It is nevertheless interesting to notice that both the negative and the positive aspects bring out importance of the concept for the professional character of caring. The tradition of ideas in medieval Christian mysticism with reference to Lévinas' ethic of responsibility offers a deeper perspective in which the meaningfulness of sacrifice in the caring relationship can be sought. The theme of sacrifice is not of interest merely as a carer's ethical outlook, but sacrifice can also be understood as a potential process of transformation health. The instinctive or conscious experience of sacrifice on the part of the individual patient can, on a symbolic level, be regarded as analogous to the cultic or religious sacrifice aiming at atonement. Sacrifice appears to the patient as an act of
Deepwater Horizon Accident Investigation Report
International Nuclear Information System (INIS)
2010-09-01
On the evening of April 20, 2010, a well control event allowed hydrocarbons to escape from the Macondo well onto Transocean's Deepwater Horizon, resulting in explosions and fire on the rig. Eleven people lost their lives, and 17 others were injured. The fire, which was fed by hydrocarbons from the well, continued for 36 hours until the rig sank. Hydrocarbons continued to flow from the reservoir through the wellbore and the blowout preventer (BOP) for 87 days, causing a spill of national significance. BP Exploration and Production Inc. was the lease operator of Mississippi Canyon Block 252, which contains the Macondo well. BP formed an investigation team that was charged with gathering the facts surrounding the accident, analyzing available information to identify possible causes and making recommendations to enable prevention of similar accidents in the future. The BP investigation team began its work immediately in the aftermath of the accident, working independently from other BP spill response activities and organizations. The ability to gather information was limited by a scarcity of physical evidence and restricted access to potentially relevant witnesses. The team had access to partial real-time data from the rig, documents from various aspects of the Macondo well's development and construction, witness interviews and testimony from public hearings. The team used the information that was made available by other companies, including Transocean, Halliburton and Cameron. Over the course of the investigation, the team involved over 50 internal and external specialists from a variety of fields: safety, operations, subsea, drilling, well control, cementing, well flow dynamic modeling, BOP systems and process hazard analysis. This report presents an analysis of the events leading up to the accident, eight key findings related to the causal chain of events and recommendations to enable the prevention of a similar accident. The investigation team worked separately
Deepwater Horizon Accident Investigation Report
Energy Technology Data Exchange (ETDEWEB)
NONE
2010-09-15
On the evening of April 20, 2010, a well control event allowed hydrocarbons to escape from the Macondo well onto Transocean's Deepwater Horizon, resulting in explosions and fire on the rig. Eleven people lost their lives, and 17 others were injured. The fire, which was fed by hydrocarbons from the well, continued for 36 hours until the rig sank. Hydrocarbons continued to flow from the reservoir through the wellbore and the blowout preventer (BOP) for 87 days, causing a spill of national significance. BP Exploration and Production Inc. was the lease operator of Mississippi Canyon Block 252, which contains the Macondo well. BP formed an investigation team that was charged with gathering the facts surrounding the accident, analyzing available information to identify possible causes and making recommendations to enable prevention of similar accidents in the future. The BP investigation team began its work immediately in the aftermath of the accident, working independently from other BP spill response activities and organizations. The ability to gather information was limited by a scarcity of physical evidence and restricted access to potentially relevant witnesses. The team had access to partial real-time data from the rig, documents from various aspects of the Macondo well's development and construction, witness interviews and testimony from public hearings. The team used the information that was made available by other companies, including Transocean, Halliburton and Cameron. Over the course of the investigation, the team involved over 50 internal and external specialists from a variety of fields: safety, operations, subsea, drilling, well control, cementing, well flow dynamic modeling, BOP systems and process hazard analysis. This report presents an analysis of the events leading up to the accident, eight key findings related to the causal chain of events and recommendations to enable the prevention of a similar accident. The investigation team worked
Super-horizon primordial black holes
International Nuclear Information System (INIS)
Harada, Tomohiro; Carr, B.J.
2005-01-01
We discuss a new class of solutions to the Einstein equations which describe a primordial black hole (PBH) in a flat Friedmann background. Such solutions arise if a Schwarzschild black hole is patched onto a Friedmann background via a transition region. They are possible providing the black hole event horizon is larger than the cosmological apparent horizon. Such solutions have a number of strange features. In particular, one has to define the black hole and cosmological horizons carefully and one then finds that the mass contained within the black hole event horizon decreases when the black hole is larger than the Friedmann cosmological apparent horizon, although its area always increases. These solutions involve two distinct future null infinities and are interpreted as the conversion of a white hole into a black hole. Although such solutions may not form from gravitational collapse in the same way as standard PBHs, there is nothing unphysical about them, since all energy and causality conditions are satisfied. Their conformal diagram is a natural amalgamation of the Kruskal diagram for the extended Schwarzschild solution and the conformal diagram for a black hole in a flat Friedmann background. In this paper, such solutions are obtained numerically for a spherically symmetric universe containing a massless scalar field, but it is likely that they exist for more general matter fields and less symmetric systems
Antecedents and outcomes of meaningful work among school teachers
Directory of Open Access Journals (Sweden)
Elmari Fouché
2017-03-01
Research purpose: The aim of this study was to investigate antecedents and outcomes of meaningful work among school teachers. Motivation for the study: Meaningful work underpins people’s motivation and affects their well-being and job satisfaction. Furthermore, it is a significant pathway to healthy and authentic organisations. However, a research gap exists regarding the effects of different antecedents and outcomes of meaningful work. Research approach, design and method: A cross-sectional survey was used with a convenience sample of 513 teachers. The Work-Life Questionnaire, Revised Job Diagnostic Survey, Co-worker Relations Scale, Work and Meaning Inventory, Personal Resources Scale, Work Engagement Scale, Turnover Intention Scale and a measure of self-rated performance were administered. Main findings: A calling orientation, job design and co-worker relations were associated with meaningful work. A low calling orientation and poor co-worker relationships predicted burnout. A calling orientation, a well-designed job, good co-worker relationships and meaningful work predicted work engagement. Job design was moderately associated with self-ratings of performance. The absence of a calling orientation predicted teachers’ intention to leave the organisation. Practical/managerial implications: Educational managers should consider implementing interventions to affect teachers’ calling orientation (through job crafting, perceptions of the nature of their jobs (by allowing autonomy and co-worker relations (through teambuilding to promote perceptions of meaningful work. Promoting perceptions of meaningful work might contribute to lower burnout, higher work engagement, better self-ratings of performance and retention of teachers. Contribution/value-add: This study contributes to scientific knowledge regarding the effects of three antecedents, namely a calling orientation, job design and co-worker relationships on meaningful work. It also contributed to knowledge
Quantum-corrected geometry of horizon vicinity
Energy Technology Data Exchange (ETDEWEB)
Park, I.Y. [Department of Applied Mathematics, Philander Smith College, Little Rock, AR (United States)
2017-12-15
We study the deformation of the horizon-vicinity geometry caused by quantum gravitational effects. Departure from the semi-classical picture is noted, and the fact that the matter part of the action comes at a higher order in Newton's constant than does the Einstein-Hilbert term is crucial for the departure. The analysis leads to a Firewall-type energy measured by an infalling observer for which quantum generation of the cosmological constant is critical. The analysis seems to suggest that the Firewall should be a part of such deformation and that the information be stored both in the horizon-vicinity and asymptotic boundary region. We also examine the behavior near the cosmological horizon. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
A global string with an event horizon
International Nuclear Information System (INIS)
Harari, D.; Polychronakos, A.P.
1990-01-01
An idealized infinite straight global string in flat space-time has a logarithmically divergent energy per unit length. With gravity included, the standard field theoretical model for a straight global string has been shown to give rise to a repulsive gravitational field, and to develop a curvature singularity at a finite proper distance off the string core. Here we point out that alternative (although probably unrealistic) equations of state for the core of the global string produce a non-singular cylindrically symmetric metric with an event horizon at a finite proper distance off the core, such that timelike observers beyond the horizon are bound to move away from the string. The same geometric structure applies to the standard field theoretical model for a vortex in (2+1)-dimensional gravity. Thermal effects in a quantum field theory around the string due to the presence of the horizon are also calculated. (orig.)
Quantum-corrected geometry of horizon vicinity
International Nuclear Information System (INIS)
Park, I.Y.
2017-01-01
We study the deformation of the horizon-vicinity geometry caused by quantum gravitational effects. Departure from the semi-classical picture is noted, and the fact that the matter part of the action comes at a higher order in Newton's constant than does the Einstein-Hilbert term is crucial for the departure. The analysis leads to a Firewall-type energy measured by an infalling observer for which quantum generation of the cosmological constant is critical. The analysis seems to suggest that the Firewall should be a part of such deformation and that the information be stored both in the horizon-vicinity and asymptotic boundary region. We also examine the behavior near the cosmological horizon. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Horizon thermodynamics in fourth-order gravity
Directory of Open Access Journals (Sweden)
Meng-Sen Ma
2017-03-01
Full Text Available 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.
On Long Memory Origins and Forecast Horizons
DEFF Research Database (Denmark)
Vera-Valdés, J. Eduardo
Most long memory forecasting studies assume that the memory is generated by the fractional difference operator. We argue that the most cited theoretical arguments for the presence of long memory do not imply the fractional difference operator, and assess the performance of the autoregressive...... fractionally integrated moving average (ARFIMA) model when forecasting series with long memory generated by nonfractional processes. We find that high-order autoregressive (AR) models produce similar or superior forecast performance than ARFIMA models at short horizons. Nonetheless, as the forecast horizon...... increases, the ARFIMA models tend to dominate in forecast performance. Hence, ARFIMA models are well suited for forecasts of long memory processes regardless of the long memory generating mechanism, particularly for medium and long forecast horizons. Additionally, we analyse the forecasting performance...
Hair-brane ideas on the horizon
International Nuclear Information System (INIS)
Martinec, Emil J.; Niehoff, Ben E.
2015-01-01
We continue an examination of the microstate geometries program begun in arXiv:1409.6017, focussing on the role of branes that wrap the cycles which degenerate when a throat in the geometry deepens and a horizon forms. An associated quiver quantum mechanical model of minimally wrapped branes exhibits a non-negligible fraction of the gravitational entropy, which scales correctly as a function of the charges. The results suggest a picture of AdS_3/CFT_2 duality wherein the long string that accounts for BTZ black hole entropy in the CFT description, can also be seen to inhabit the horizon of BPS black holes on the gravity side.
Callings, work role fit, psychological meaningfulness and work ...
African Journals Online (AJOL)
meaningful work experiences, which also impact individuals' work .... group 25 to 29 years. .... significant chi-squared difference tests, after these path deletions, indicated that .... Counseling Psychology, 59:479-485. doi: 10.1037/a0028949.
Readiness for Meaningful Use of Health Information Tech...
U.S. Department of Health & Human Services — According to findings reported in Readiness for Meaningful Use of Health Information Technology and Patient Centered Medical Home Recognition Survey Results,...
Meaningful work and secondary school teachers' intention to leave
Janik, M.; Rothmann, S.
2015-01-01
The study investigates the relations between secondary school teachers' work-role fit, job enrichment, supervisor relationships, co-worker relationships, psychological meaningfulness of work and intention to leave. A cross-sectional survey was used. The participants were 502 secondary school teachers in Namibia. The following measuring instruments were used: Work-role Fit Scale, Job Enrichment Scale, Co-worker and Supervisor Relationships Scales, Psychological Meaningfulness Scale and Turnove...
Design democratization with communities: Drawing toward locally meaningful design
DEFF Research Database (Denmark)
Winschiers-Goagoses, Naska; Winschiers-Theophilus, Heike; Rodil, Kasper
2012-01-01
The authors present community drawing as meaningful representations to inform locally valid technology design. They investigate recognition within and across cultural borders, thereby exposing variances of localities. The study contributes to the still scarce body of empirical work on culturally...... meaningful development of visual representations and recognition, as part of a longitudinal research project in which we co-design a 3D visualization for a specific Namibian pilot site....
PROMOTING MEANINGFUL LEARNING THROUGH CREATE-SHARE-COLLABORATE
Sailin, Siti Nazuar; Mahmor, Noor Aida
2017-01-01
Students in this 21st century are required to acquire these 4C skills: Critical thinking, Communication, Collaboration and Creativity. These skills can be integrated in the teaching and learning through innovative teaching that promotes active and meaningful learning. One way of integrating these skills is through collaborative knowledge creation and sharing. This paper providesan example of meaningful teaching and learning activities designed within the Create-Share-Collaborate instructional...
Self-Determination and Meaningful Work: Exploring Socioeconomic Constraints
Allan, Blake A.; Autin, Kelsey L.; Duffy, Ryan D.
2016-01-01
This study examined a model of meaningful work among a diverse sample of working adults. From the perspectives of Self-Determination Theory and the Psychology of Working Framework, we tested a structural model with social class and work volition predicting SDT motivation variables, which in turn predicted meaningful work. Partially supporting hypotheses, work volition was positively related to internal regulation and negatively related to amotivation, whereas social class was positively relat...
New view about black holes. [Tachyon--bradyon transformation at horizon
Energy Technology Data Exchange (ETDEWEB)
De Sabbata, V; Pavsic, M; Recami, E
1977-01-01
For a Schwarzschild black-hole, as reference frame is chosen the frame sigma at rest with respect to the Schwarzschild metric. In this locally non-inertial frame, a freely falling body is shown to reach the speed of light on the horizon and then to travel faster than light inside the horizon. The usual Szekeres--Kruskal (SK) coordinates represent themselves frames that (with respect to the frames sigma) travel at subluminal speed outside, at luminal speed on, and at superluminal speed inside the horizon (so that SK frames always describe any free falling body as a standard, slower-than-light object). Finally, black-holes are shown to be possible sources of tachyons.
Classification of Near-Horizon Geometries of Extremal Black Holes.
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.
The co-creation of meaningful action: bridging enaction and interactional sociology
Peräkylä, Anssi; Stevanovic, Melisa
2016-01-01
What makes possible the co-creation of meaningful action? In this paper, we go in search of an answer to this question by combining insights from interactional sociology and enaction. Both research schools investigate social interactions as such, and conceptualize their organization in terms of autonomy. We ask what it could mean for an interaction to be autonomous, and discuss the structures and processes that contribute to and are maintained in the so-called interaction order. We also discuss the role played by individual vulnerability as well as the vulnerability of social interaction processes in the co-creation of meaningful action. Finally, we outline some implications of this interdisciplinary fraternization for the empirical study of social understanding, in particular in social neuroscience and psychology, pointing out the need for studies based on dynamic systems approaches on origins and references of coordination, and experimental designs to help understand human co-presence. PMID:27069055
The co-creation of meaningful action: bridging enaction and interactional sociology.
De Jaegher, Hanne; Peräkylä, Anssi; Stevanovic, Melisa
2016-05-05
What makes possible the co-creation of meaningful action? In this paper, we go in search of an answer to this question by combining insights from interactional sociology and enaction. Both research schools investigate social interactions as such, and conceptualize their organization in terms of autonomy. We ask what it could mean for an interaction to be autonomous, and discuss the structures and processes that contribute to and are maintained in the so-called interaction order. We also discuss the role played by individual vulnerability as well as the vulnerability of social interaction processes in the co-creation of meaningful action. Finally, we outline some implications of this interdisciplinary fraternization for the empirical study of social understanding, in particular in social neuroscience and psychology, pointing out the need for studies based on dynamic systems approaches on origins and references of coordination, and experimental designs to help understand human co-presence. © 2016 The Authors.
The effect of occupational meaningfulness on occupational commitment
Directory of Open Access Journals (Sweden)
Itai Ivtzan
2014-11-01
Full Text Available Existing research lacks a scholarly consensus on how to define and validly measure ‘meaningful work’ (e.g., Rosso, Dekas & Wrzesniewski, 2010. The following correlational study highlights the value of investigating meaningfulness in the context of occupational commitment. The study hypothesizes that occupational commitment is positively correlated with occupational meaningfulness, where meaningfulness is defined as the extent to which people’s occupations contribute to personal meaning in life. One-hundred and fifty-six full-time office based UK workers completed an online questionnaire including 18 questions measuring levels of occupational commitment (Meyer, Allen & Smith, 1993, in addition to six novel items measuring occupational meaningfulness. The results supported the hypothesis and also showed that the affective sub-type of occupational commitment had the highest correlation with occupational meaningfulness. Such results exhibit the importance of finding meaning at work, as well as the relevance of this to one’s level of commitment to his or her job. This paper argues that individuals should consider OM before choosing to take a specific role, whereas organizations ought to consider the OM of their potential candidates before recruiting them into a role. Possible directions for future research directions are also discussed.
Helping others increases meaningful work: Evidence from three experiments.
Allan, Blake A; Duffy, Ryan D; Collisson, Brian
2018-03-01
The aim of the current research was to examine whether manipulating task significance increased the meaningfulness of work among students (Study 1), an online sample of working adults (Study 2), and public university employees (Study 3). In Study 1, students completed a typing task for the benefit of themselves, a charity, or someone they knew would directly benefit from their work. People who worked to benefit someone else, rather than themselves, reported greater task meaningfulness. In Study 2, a representative, online sample of employees reflected on a time when they worked to benefit themselves or someone else at work. Results revealed that people who reflected on working to benefit someone else, rather than themselves, reported greater work meaningfulness. In Study 3, public university employees participated in a community intervention by working as they normally would, finding new ways to help people each day, or finding several new ways to help others on a single day. People who helped others many times in a single day experienced greater gains in work meaningfulness over time. Across 3 experimental studies, we found that people who perceived their work as helping others experienced more meaningfulness in their work. This highlights the potential mechanisms practitioners, employers, and other parties can use to increase the meaningfulness of work, which has implications for workers' well-being and productivity. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Meaningful work and mental health: job satisfaction as a moderator.
Allan, Blake A; Dexter, Chelsea; Kinsey, Rebecca; Parker, Shelby
2018-02-01
Depression, anxiety and stress are common problems for modern workers. Although having meaningful work, or work that is significant, facilitates personal growth, and contributes to the greater good, has been linked to better mental health, people's work might also need to be satisfying or enjoyable to improve outcomes. The purpose of the present study was to examine meaningful work's relation to mental health (i.e. depression, anxiety and stress) and investigate job satisfaction as a moderator of this relation. The study hypotheses were tested with a large, diverse sample recruited from an online source. Partially supporting hypotheses, when controlling for job satisfaction, meaningful work negatively correlated with depression but did not have a significant relation with anxiety and stress. Similarly, job satisfaction negatively predicted depression and stress. Furthermore, the relations between meaningful work and both anxiety and stress were moderated by job satisfaction. Specifically, only people perceiving their work as meaningful and satisfying reported less anxiety and stress. Although continued research is needed, employers and employees may have to target both the meaningfulness and job satisfaction to address the issues of stress and anxiety among working adults.
Sighting Horizons of Teaching in Higher Education
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…
Falling through the black hole horizon
International Nuclear Information System (INIS)
Brustein, Ram; Medved, A.J.M.
2015-01-01
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 strain 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.
The Horizon Is An Imaginary Line
DEFF Research Database (Denmark)
Gill, Bani; Mahendru, Radha
The Horizon Is An Imaginary Line (THIAI) is a semi-fictional illustrated account of a young Somali woman's encounters as a refugee in India. Through Maryam, we reflect on the lived experiences of alienation and marginalization as an 'outsider' on the fringes of an increasingly bordered world...
Expanding Your Horizons Conference in Geneva
Chromek-Burckhart, Doris
2011-01-01
CERN and its experiments participated in Expanding Your Horizons (EYH) in Science and Mathematics conference in Geneva on 12th November. EYH nurture girls' interest in science and math courses to encourage them to consider careers in science, technology, engineering, and math.
Agriculture’s Ethical Horizon, book review
Roughly 6.5 billion people inhabit the earth, but over 1 billion people regularly go hungry. This food shortfall poses an ethical dilemma for agriculture, and Agriculture's Ethical Horizon grapples with this dilemma. It argues that agricultural productivity has been the quintessential value of agr...
The NMC Horizon Report: 2013 Museum Edition
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…
Pricing Liquidity Risk with Heterogeneous Investment Horizons
Beber, A.; Driessen, J.; Tuijp, P.F.A.
2012-01-01
We develop a new asset pricing model with stochastic transaction costs and investors with heterogenous horizons. Short-term investors hold only liquid assets in equilibrium. This generates segmentation effects in the pricing of liquid versus illiquid assets. Specifically, the liquidity (risk) premia
Casimir effect and thermodynamics of horizon instabilities
International Nuclear Information System (INIS)
Hartnoll, Sean A.
2004-01-01
We propose a dual thermodynamic description of a classical instability of generalized black hole spacetimes. From a thermodynamic perspective, the instability is due to negative compressibility in regions where the Casimir pressure is large. The argument indicates how the correspondence between thermodynamic and classical instability for horizons may be extended to cases without translational invariance
Valuing modular nuclear power plants in finite time decision horizon
International Nuclear Information System (INIS)
Jain, Shashi; Roelofs, Ferry; Oosterlee, Cornelis W.
2013-01-01
Small and medium sized reactors, SMRs, (according to IAEA, ‘small’ refers to reactors with power less than 300 MWe, and ‘medium’ with power less than 700 MWe) are considered as an attractive option for investment in nuclear power plants. SMRs may benefit from flexibility of investment, reduced upfront expenditure, enhanced safety, and easy integration with small sized grids. Large reactors on the other hand have been an attractive option due to the economy of scale. In this paper we focus on the economic impact of flexibility due to modular construction of SMRs. We demonstrate, using real option analysis, the value of sequential modular SMRs. Numerical results under different considerations of decision time, uncertainty in electricity prices, and constraints on the construction of units, are reported for a single large unit and for modular SMRs. - Highlights: ► Real option value of modular construction in finite time decision horizon. ► Stochastic grid method is used to value the real option. ► Decisions in finite time can differ significantly from infinite decision time. ► Decisions depend on length of decision horizon and price volatilities
Structure of diagnostics horizons and humus classification
Directory of Open Access Journals (Sweden)
Zanella A
2008-03-01
Full Text Available The classification of the main humus forms is generally based on the morpho-genetic characters of the A and OH diagnostic horizons. This is the case in the new European key of classification presented in Freiburg on September 2004 (Eurosoil Congress. Among the morpho-genetic characters, the soil structure covers a very important role. In this work, the structure of the diagnostic A and OH horizons has been analysed in terms of aggregation force, diameter and composition of the soil lumps (peds. In order to study the aggregation force, two disaggregating tools have been conceived and used. The diameter of the lumps has been measured by sieving the soil samples with standardised webs. Observing the samples thanks to a binocular magnifying 10X and 50X, the organic or/and mineral composition of the soil aggregates has been determined, data being investigated with ANOVA and Factorial Analysis. The article examines the argument from two points of view: crashing tools for estimating the soil structure (part 1 and the dimensions of the peds given in European key of humus forms classification (part 2. The categories of soil peds diameter and composition seem to be linked to the main humus forms. For instance, aggregates having a diamater larger than 1 mm and well amalgamate organo-mineral composition are more present in the A horizons of the Mull forms than in which of the other forms; contrary to the OH horizon of the Moder or Mor, the OH horizon of the Amphi forms shows an important percent of small organic lumps. Some propositions have been given in order to improve the European key of humus forms classification.
What happens at the horizon(s) of an extreme black hole?
International Nuclear Information System (INIS)
Murata, Keiju; Reall, Harvey S; Tanahashi, Norihiro
2013-01-01
A massless scalar field exhibits an instability at the event horizon of an extreme black hole. We study numerically the nonlinear evolution of this instability for spherically symmetric perturbations of an extreme Reissner–Nordstrom (RN) black hole. We find that generically the endpoint of the instability is a non-extreme RN solution. However, there exist fine-tuned initial perturbations for which the instability never decays. In this case, the perturbed spacetime describes a time-dependent extreme black hole. Such solutions settle down to extreme RN outside, but not on, the event horizon. The event horizon remains smooth but certain observers who cross it at late time experience large gradients there. Our results indicate that these dynamical extreme black holes admit a C 1 extension across an inner (Cauchy) horizon. (paper)
Deepwater Horizon Seafood Safety Response - Deepwater Horizon Oil Spill Seafood Safety Response
National Oceanic and Atmospheric Administration, Department of Commerce — In the aftermath of the Deepwater Horizon oil spill in 2010, there was concern about the risk to human health through consumption of contaminated seafood from the...
Reflection, radiation, and interference near the black hole horizon
International Nuclear Information System (INIS)
Kuchiev, M.Yu.
2004-01-01
The event horizon of black holes is capable of reflection: there is a finite probability for any particle that approaches the horizon to bounce back. The albedo of the horizon depends on the black hole temperature and the energy of the incoming particle. The reflection shares its physical origins with the Hawking process of radiation; both of them arise as consequences of the mixing of the incoming and outgoing waves that takes place due to quantum processes on the event horizon
Hydrological classification of orthic A horizons in Weatherley, South ...
African Journals Online (AJOL)
Orthic A horizons carry little interpretive, especially hydrological, value. This paper aims to elucidate the hydrological interpretation of orthic A horizons. Measured water contents in the orthic A horizons of 28 profiles in the Weatherley catchment of South Africa were used to classify the topsoils into wetness classes. The very ...
Writing More Informative Letters of Reference
Wright, Scott M; Ziegelstein, Roy C
2004-01-01
Writing a meaningful and valuable letter of reference is not an easy task. Several factors influence the quality of any letter of reference. First, the accuracy and reliability of the writer's impressions and judgment depend on how well he knows the individual being described. Second, the writer's frame of reference, which is determined by the number of persons at the same level that he has worked with, will impact the context and significance of his beliefs and estimations. Third, the letter...
Hair-brane ideas on the horizon
Energy Technology Data Exchange (ETDEWEB)
Martinec, Emil J. [Enrico Fermi Institute and Department of Physics, University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637-1433 (United States); Niehoff, Ben E. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge,Centre for Mathematical Sciences,Wilberforce Rd., Cambridge, CB3 0WA (United Kingdom)
2015-11-27
We continue an examination of the microstate geometries program begun in arXiv:1409.6017, focussing on the role of branes that wrap the cycles which degenerate when a throat in the geometry deepens and a horizon forms. An associated quiver quantum mechanical model of minimally wrapped branes exhibits a non-negligible fraction of the gravitational entropy, which scales correctly as a function of the charges. The results suggest a picture of AdS{sub 3}/CFT{sub 2} duality wherein the long string that accounts for BTZ black hole entropy in the CFT description, can also be seen to inhabit the horizon of BPS black holes on the gravity side.
Rogue events in the group velocity horizon.
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.
Buuren, S. van
2007-01-01
A growth reference describes the variation of an anthropometric measurement within a group of individuals. A reference is a tool for grouping and analyzing data and provides a common basis for comparing populations.1 A well known type of reference is the age-conditional growth diagram. The
VMware Horizon 6 desktop virtualization solutions
Cartwright, Ryan; Langone, Jason; Leibovici, Andre
2014-01-01
If you are a desktop architect, solution provider, end-user consultant, virtualization engineer, or anyone who wants to learn how to plan and design the implementation of a virtual desktop solution based on Horizon 6, then this book is for you. An understanding of VMware vSphere fundamentals coupled with experience in the installation or administration of a VMware environment would be a plus during reading.
New Horizons Pluto Flyby Guest Operations
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.
Designing Meaningful Game Experiences for Rehabilitation and Sustainable Mobility Settings
Directory of Open Access Journals (Sweden)
Silvia Gabrielli
2014-03-01
Full Text Available This paper presents the approach followed in two ongoing research projects aimed to designing meaningful game-based experiences to support home rehabilitation, eco-sustainable mobility goals and more in general better daily lifestyles. We first introduce the need for designing meaningful game-based experiences that are well-connected to the relevant non-game settings and can be customized by/for users, then, we show examples of how this approach can be realized in the rehabilitation and sustainable mobility contexts.
Fiber-optical analog of the event horizon.
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.
Turnpike phenomenon and infinite horizon optimal control
Zaslavski, Alexander J
2014-01-01
This book is devoted to the study of the turnpike phenomenon and describes the existence of solutions for a large variety of infinite horizon optimal control classes of problems. Chapter 1 provides introductory material on turnpike properties. Chapter 2 studies the turnpike phenomenon for discrete-time optimal control problems. The turnpike properties of autonomous problems with extended-value intergrands are studied in Chapter 3. Chapter 4 focuses on large classes of infinite horizon optimal control problems without convexity (concavity) assumptions. In Chapter 5, the turnpike results for a class of dynamic discrete-time two-player zero-sum game are proven. This thorough exposition will be very useful for mathematicians working in the fields of optimal control, the calculus of variations, applied functional analysis, and infinite horizon optimization. It may also be used as a primary text in a graduate course in optimal control or as supplementary text for a variety of courses in other disciplines. Resea...
Isolated and Dynamical Horizons and Their Applications
Directory of Open Access Journals (Sweden)
Ashtekar Abhay
2004-12-01
Full Text Available Over the past three decades, black holes have played an important role in quantum gravity, mathematical physics, numerical relativity and gravitational wave phenomenology. However, conceptual settings and mathematical models used to discuss them have varied considerably from one area to another. Over the last five years a new, quasi-local framework was introduced to analyze diverse facets of black holes in a unified manner. In this framework, evolving black holes are modelled by dynamical horizons and black holes in equilibrium by isolated horizons. We review basic properties of these horizons and summarize applications to mathematical physics, numerical relativity, and quantum gravity. This paradigm has led to significant generalizations of several results in black hole physics. Specifically, it has introduced a more physical setting for black hole thermodynamics and for black hole entropy calculations in quantum gravity, suggested a phenomenological model for hairy black holes, provided novel techniques to extract physics from numerical simulations, and led to new laws governing the dynamics of black holes in exact general relativity.
Meaningful Work and Secondary School Teachers' Intention to Leave
Janik, M.; Rothmann, S.
2015-01-01
The study investigates the relations between secondary school teachers' work-role fit, job enrichment, supervisor relationships, co-worker relationships, psychological meaningfulness of work and intention to leave. A cross-sectional survey was used. The participants were 502 secondary school teachers in Namibia. The following measuring instruments…
Meaningful community involvement in protected area issues: a dialogue session
Laurie Yung
2000-01-01
The current effort to rethink public involvement in decision-making processes for federal lands is gaining momentum. Advocates of alternative decision-making processes seek to involve communities in more meaningful ways than traditional NEPA-style public participation. These new processes take the form of citizen monitoring, partnerships, and most often, collaboration...
Pedagogical Principles of Learning to Teach Meaningful Physical Education
Ní Chróinín, Déirdre; Fletcher, Tim; O'Sullivan, Mary
2018-01-01
Background: Concerns that current forms of physical education teacher education (PETE) are not adequately providing teachers with the tools necessary for working with the realities and challenges of teaching physical education in contemporary schools has led some scholars to advocate for an approach that prioritises meaningfulness in physical…
Callings, work role fit, psychological meaningfulness and work ...
African Journals Online (AJOL)
Our aim in this study was to investigate the relationships among a calling orientation, work role fit, psychological meaningfulness and work engagement of teachers in Zambia. A quantitative approach was followed and a cross-sectional survey was used. The sample (n = 150) included 75 basic and 75 secondary school ...
Morality and a Meaningful Life | Thomas | Philosophical Papers
African Journals Online (AJOL)
... healthy dovetail with respect to leading a meaningful life. With this argument regarding psychological health I draw upon, and extend, P. F. Strawson's seminal essay “Freedom and Resentment”. Also in this regard, I extend Wittgenstein's argument against the possibility of a private language to social behavior generally.
Water Habitat Study: Prediction Makes It More Meaningful.
Glasgow, Dennis R.
1982-01-01
Suggests a teaching strategy for water habitat studies to help students make a meaningful connection between physiochemical data (dissolved oxygen content, pH, and water temperature) and biological specimens they collect. Involves constructing a poster and using it to make predictions. Provides sample poster. (DC)
Cultural study in design : In search of a meaningful approach
van Boeijen, A.G.C.
2014-01-01
Does the Circuit of Culture help design students to do a cultural study that is meaningful for their design project? Indeed, it provides a good view on the phenomenon culture, its complexity and how contemporary cultures can be studied, providing an overview and structure of the processes that
Meaningful Gamification in an Industrial/Organizational Psychology Course
Stansbury, Jessica A.; Earnest, David R.
2017-01-01
Motivation and game research continue to demonstrate that the implementation of game design characteristics in the classroom can be engaging and intrinsically motivating. The present study assessed the extent to which an industrial organizational psychology course designed learning environment created with meaningful gamification elements can…
Using Meaningful Contexts to Promote Understanding of Pronumerals
Linsell, Chris; Cavanagh, Michael; Tahir, Salma
2013-01-01
Developing a conceptual understanding of elementary algebra has been the focus of a number of recent articles in this journal. Baroudi (2006) advocated problem solving to assist students' transition from arithmetic to algebra, and Shield (2008) described the use of meaningful contexts for developing the concept of function. Samson (2011, 2012)…
Comprehension for What? Preparing Students for Their Meaningful Future
Conley, Mark W.; Wise, Antoinette
2011-01-01
Researchers, policymakers, and educators face a daunting task these days concerning literacy education for the here and now and literacy for the future. Even though one clings to the romantic notion that education provides the building blocks in a straight line to a meaningful future, the reality is that mixed goals and instructional messages…
Operating Room Delays: Meaningful Use in Electronic Health Record.
Van Winkle, Rachelle A; Champagne, Mary T; Gilman-Mays, Meri; Aucoin, Julia
2016-06-01
Perioperative areas are the most costly to operate and account for more than 40% of expenses. The high costs prompted one organization to analyze surgical delays through a retrospective review of their new electronic health record. Electronic health records have made it easier to access and aggregate clinical data; 2123 operating room cases were analyzed. Implementing a new electronic health record system is complex; inaccurate data and poor implementation can introduce new problems. Validating the electronic health record development processes determines the ease of use and the user interface, specifically related to user compliance with the intent of the electronic health record development. The revalidation process after implementation determines if the intent of the design was fulfilled and data can be meaningfully used. In this organization, the data fields completed through automation provided quantifiable, meaningful data. However, data fields completed by staff that required subjective decision making resulted in incomplete data nearly 24% of the time. The ease of use was further complicated by 490 permutations (combinations of delay types and reasons) that were built into the electronic health record. Operating room delay themes emerged notwithstanding the significant complexity of the electronic health record build; however, improved accuracy could improve meaningful data collection and a more accurate root cause analysis of operating room delays. Accurate and meaningful use of data affords a more reliable approach in quality, safety, and cost-effective initiatives.
Synonyms, Antonyms, and Retroactive Inhibition with Meaningful Material
Weisshed, Ethel
1973-01-01
The determination of the extent to which generalizations derived from studies of rote verbal learning, particularly paired-associate learning applied to highly meaningful materials, was the focus of this study. It was found that discriminating tags to synonyms and antonyms permitting the application of appropriate transfer rules may be attached.…
Types of Meaningfulness of Life and Values of Future Teachers
Salikhova, Nailia R.
2016-01-01
The leading role of meaning of life in regulation of human's activity of all types provides the relevance of the research. The goal of the paper is to identify and describe types of meaningfulness of life in future teachers, and to reveal the specificity of values hierarchy indicative of each type. The leading approach applied in the research was…
How Do Novice Art Teachers Define and Implement Meaningful Curriculum?
Bain, Christina; Newton, Connie; Kuster, Deborah; Milbrandt, Melody
2010-01-01
Four researchers collaborated on this qualitative case study that examined 11 first-year novice art teachers' understanding and implementation of meaningful curriculum. Participants were selected through a criterion method sampling strategy; the subjects were employed in rural, urban, and suburban public school districts. In order to conduct a…
Authentic Leadership and Altruism: The Mediating Role of Meaningfulness
Sagnak, Mesut; Kuruöz, Mehmet
2017-01-01
The purpose of this study was to investigate the mediating effects of meaningfulness on the relationship between authentic leadership and altruistic behavior. The participants consisted of 356 teachers randomly selected from 14 primary and secondary schools in Nigde. Three different instruments were used in this study. The scales were translated…
Modeling Meaningful Learning in Chemistry Using Structural Equation Modeling
Brandriet, Alexandra R.; Ward, Rose Marie; Bretz, Stacey Lowery
2013-01-01
Ausubel and Novak's construct of "meaningful learning" stipulates that substantive connections between new knowledge and what is already known requires the integration of thinking, feeling, and performance (Novak J. D., (2010), "Learning, creating, and using knowledge: concept maps as facilitative tools in schools and…
Work engagement and meaningful work across generational cohorts
Directory of Open Access Journals (Sweden)
Crystal Hoole
2015-08-01
Full Text Available Orientation: Engaging employees and providing employees with a sense of meaning at work is not a one-size-fits-all approach. Although research has shown that differences between work engagement and meaningful work amongst generational cohorts exist, results are still inconclusive. With age becoming increasingly more important as a diversity factor, a better understanding of the dynamics between work engagement and meaningful work across different generational cohorts is necessary to design the right strategy for each organisation’s unique parameters. Research purpose: The aim of this study was to determine whether there is a relationship between work engagement and meaningful work and whether there are significant variances between the levels of work engagement and meaningful work between different generational cohorts. Motivation for study: Work engagement has consistently been highlighted by researchers and human resources experts as a recommended solution to provide companies with the upper hand when it comes to creating a competitive edge. Yet, levels of work engagement are far from ideal, requiring intensified efforts to identify solutions towards raising overall engagement levels. In recent years, much of the focus in terms of generating engagement has been aimed in the direction of financial rewards and other benefits; some organisational experts are of the opinion that a shift is occurring towards meaningful work instead of monetary rewards as the driver of engagement. The changing nature of the work landscape also suggests that generational cohorts experience work engagement and meaningful work differently. Understanding these complexities is mandatory in creating solutions towards improving levels of engagement and meaningful work. Research approach, design and method: A cross-sectional quantitative research approach has been followed. The Utrecht Work Engagement Scale (UWES and Psychological Meaningful Scale (PMS were administered
Brkić, Silvija
2013-01-01
Scientific and professional papers represent the information basis for scientific research and professional work. References important for the paper should be cited within the text, and listed at the end of the paper. This paper deals with different styles of reference citation. Special emphasis was placed on the Vancouver Style for reference citation in biomedical journals established by the International Committee of Medical Journal Editors. It includes original samples for citing various types of articles, both printed and electronic, as well as recommendations related to reference citation in accordance with the methodology and ethics of scientific research and guidelines for preparing manuscripts for publication.
Bivens-Tatum, Wayne
2006-01-01
This article presents interesting articles that explore several different areas of reference assessment, including practical case studies and theoretical articles that address a range of issues such as librarian behavior, patron satisfaction, virtual reference, or evaluation design. They include: (1) "Evaluating the Quality of a Chat Service"…
Quantum chaos and the black hole horizon
CERN. Geneva
2016-01-01
Thanks to AdS/CFT, the analogy between black holes and thermal systems has become a practical tool, shedding light on thermalization, transport, and entanglement dynamics. Continuing in this vein, recent work has shown how chaos in the boundary CFT can be analyzed in terms of high energy scattering right on the horizon of the dual black hole. The analysis revolves around certain out-of-time-order correlation functions, which are simple diagnostics of the butterfly effect. We will review this work, along with a general bound on these functions that implies black holes are the most chaotic systems in quantum mechanics. (NB Room Change to Main Auditorium)
What's on the horizon for macroecology?
DEFF Research Database (Denmark)
Beck, Jan; Ballesteros-Mejia, Liliana; Buchmann, Carsten M.
2012-01-01
employed as a main approach, but new developments are due to be utilized. Scanning the horizon of macroecology, we identified four challenges that will probably play a major role in the future. We support our claims by examples and bibliographic analyses. 1) Integrating the past into macroecological...... to be tapped and new, small-grain large-extent data need to be collected. 4) Although macroecology already lead to mainstreaming cutting-edge statistical analysis techniques, we find that more sophisticated methods are needed to account for the biases inherent to sampling at large scale. Bayesian methods may...
The horizon of the lightest black hole
Energy Technology Data Exchange (ETDEWEB)
Calmet, Xavier [University of Sussex, Physics and Astronomy, Falmer, Brighton (United Kingdom); Casadio, Roberto [Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (Italy); I.N.F.N., Sezione di Bologna, Bologna (Italy)
2015-09-15
We study the properties of the poles of the resummed graviton propagator obtained by resumming bubble matter diagrams which correct the classical graviton propagator. These poles have been previously interpreted as black holes precursors. Here, we show using the horizon wave-function formalism that these poles indeed have properties which make them compatible with being black hole precursors. In particular, when modeled with a Breit-Wigner distribution, they have a well-defined gravitational radius. The probability that the resonance is inside its own gravitational radius, and thus that it is a black hole, is about one half. Our results confirm the interpretation of these poles as black hole precursors. (orig.)
Stringy horizons and UV/IR mixing
Energy Technology Data Exchange (ETDEWEB)
Ben-Israel, Roy [Physics Department, Tel-Aviv University Israel,Ramat-Aviv, 69978 (Israel); Giveon, Amit [Racah Institute of Physics, The Hebrew University,Jerusalem, 91904 (Israel); Itzhaki, Nissan; Liram, Lior [Physics Department, Tel-Aviv University Israel,Ramat-Aviv, 69978 (Israel)
2015-11-24
The target-space interpretation of the exact (in α{sup ′}) reflection coefficient for scattering from Euclidean black-hole horizons in classical string theory is studied. For concreteness, we focus on the solvable SL(2,ℝ){sub k}/U(1) black hole. It is shown that it exhibits a fascinating UV/IR mixing, dramatically modifying the late-time behavior of general relativity. We speculate that this might play an important role in the black-hole information puzzle, as well as in clarifying features related with the non-locality of Little String Theory.
New horizons in biomagnetics and bioimaging
International Nuclear Information System (INIS)
Ueno, Shogo; Sekino, Masaki
2006-01-01
This paper reviews recently developed techniques in biomagnetics and bioimaging such as transcranial magnetic stimulation (TMS), magnetic resonance imaging (MRI), and cancer therapy based on magnetic stimulation. The technique of localized and vectorial TMS has made it possible to obtain non-invasive functional mapping of the human brain, and the development of new bioimaging technologies such as current distribution MRI and conductivity MRI may make it possible to understand the dynamics of brain functions, which include millisecond-level changes in functional regions and dynamic relations between brain neuronal networks. These techniques are leading medicine and biology toward new horizons through novel applications of magnetism. (author)
An uneventful horizon in two dimensions
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.
An uneventful horizon in two dimensions
International Nuclear Information System (INIS)
Almheiri, Ahmed; Sully, James
2014-01-01
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
Aligning European OA policies with Horizon 2020
Picarra, Mafalda; Angelaki, Marina; Dogan, Guleda; Guy, Marieke; Artusio, Claudio
2015-01-01
This article considers that the Horizon 2020 (H2020) Open Access (OA) policy can be adopted as a policy model in European Research Area (ERA) countries for the development and increasing alignment of OA policies. Accordingly, the OA policy landscape in five ERA countries – Greece, Italy, the Netherlands, Turkey and the UK – is assessed and the extent of alignment or divergence of those policies with the H2020 OA policy is examined. The article concludes by considering some of the impacts that...
Meaningful Human Control over Autonomous Systems: A Philosophical Account
Directory of Open Access Journals (Sweden)
Filippo Santoni de Sio
2018-02-01
Full Text Available Debates on lethal autonomous weapon systems have proliferated in the past 5 years. Ethical concerns have been voiced about a possible raise in the number of wrongs and crimes in military operations and about the creation of a “responsibility gap” for harms caused by these systems. To address these concerns, the principle of “meaningful human control” has been introduced in the legal–political debate; according to this principle, humans not computers and their algorithms should ultimately remain in control of, and thus morally responsible for, relevant decisions about (lethal military operations. However, policy-makers and technical designers lack a detailed theory of what “meaningful human control” exactly means. In this paper, we lay the foundation of a philosophical account of meaningful human control, based on the concept of “guidance control” as elaborated in the philosophical debate on free will and moral responsibility. Following the ideals of “Responsible Innovation” and “Value-sensitive Design,” our account of meaningful human control is cast in the form of design requirements. We identify two general necessary conditions to be satisfied for an autonomous system to remain under meaningful human control: first, a “tracking” condition, according to which the system should be able to respond to both the relevant moral reasons of the humans designing and deploying the system and the relevant facts in the environment in which the system operates; second, a “tracing” condition, according to which the system should be designed in such a way as to grant the possibility to always trace back the outcome of its operations to at least one human along the chain of design and operation. As we think that meaningful human control can be one of the central notions in ethics of robotics and AI, in the last part of the paper, we start exploring the implications of our account for the design and use of non
TU-C-HORIZONS-01: The Expanding Horizons Travel Grant Program: ePosters and Discussion
Energy Technology Data Exchange (ETDEWEB)
Siewerdsen, J [Johns Hopkins University, Baltimore, MD (United States); Jeraj, R [University of Wisconsin, Madison, WI (United States)
2016-06-15
The Expanding Horizons travel grant program provides opportunity for students and trainees to broaden the scope of scientific meetings they attend and gain insight from research outside traditional domains of medical physics. Through participation in such conferences, early-career researchers are introduced to new topics with relevance to medical physics research as a means to expand the scientific horizons of our discipline. This year, 21 Expanding Horizons travel grants were awarded, granting travel to 17 conferences, including: Radiomics, the World Molecular Imaging Society (WMIS), the 3D Printing Conference and Expo, the GPU Technology Conference, the SIAM Imaging Science Conference, the Human Brain Mapping Conference, the OSA Conference on Clinical and Translational Biophotonics, the Society for Neuroscience, the AACR Conference on Tumor Microenvironment, and the Conference on Knowledge Discovery and Data Mining. The Expanding Horizons electronic poster session gives a venue for AAPM conference attendees to meet and discuss with awardees, learn the hot topics and emerging research areas presented at these conferences, and understand the relevance to future medical physics research.
TU-C-HORIZONS-01: The Expanding Horizons Travel Grant Program: ePosters and Discussion
International Nuclear Information System (INIS)
Siewerdsen, J; Jeraj, R
2016-01-01
The Expanding Horizons travel grant program provides opportunity for students and trainees to broaden the scope of scientific meetings they attend and gain insight from research outside traditional domains of medical physics. Through participation in such conferences, early-career researchers are introduced to new topics with relevance to medical physics research as a means to expand the scientific horizons of our discipline. This year, 21 Expanding Horizons travel grants were awarded, granting travel to 17 conferences, including: Radiomics, the World Molecular Imaging Society (WMIS), the 3D Printing Conference and Expo, the GPU Technology Conference, the SIAM Imaging Science Conference, the Human Brain Mapping Conference, the OSA Conference on Clinical and Translational Biophotonics, the Society for Neuroscience, the AACR Conference on Tumor Microenvironment, and the Conference on Knowledge Discovery and Data Mining. The Expanding Horizons electronic poster session gives a venue for AAPM conference attendees to meet and discuss with awardees, learn the hot topics and emerging research areas presented at these conferences, and understand the relevance to future medical physics research.
Hawking radiation of an apparent horizon in a FRW universe
International Nuclear Information System (INIS)
Cai Ronggen; Cao Liming; Hu Yapeng
2009-01-01
Hawking radiation is an important quantum phenomenon of a black hole, which is closely related to the existence of an event horizon of a black hole. The cosmological event horizon of de Sitter space is also of Hawking radiation with a thermal spectrum. By use of the tunneling approach, we show that there is indeed a Hawking radiation with temperature, T=1/(2πr-tilde A , for a locally defined apparent horizon of a Friedmann-Robertson-Walker universe with any spatial curvature, where r-tilde A is the apparent horizon radius. Thus we fill in the gap existing in the literature investigating the relation between the first law of thermodynamics and Friedmann equations; there the apparent horizon is assumed to have such a temperature without any proof. In addition, we stress the implication of the Hawking temperature associated with the apparent horizon.
Hawking radiation from the cosmological horizon in a FRW universe
International Nuclear Information System (INIS)
Hu Yapeng
2011-01-01
It is well known that there is a Hawking radiation from the cosmological horizon of the de Sitter spacetime, and the de Sitter spacetime can be a special case of a FRW universe. Therefore, there may be a corresponding Hawking radiation in a FRW universe. Indeed, there have been several clues showing that there is a Hawking radiation from the apparent horizon of a FRW universe. In our Letter, however, we find that the Hawking radiation may come from the cosmological horizon. Moreover, we also find that the Hawking radiation from the apparent horizon of a FRW universe in some previous works can be a special case in our result, and the condition is that the variation rate of cosmological horizon r . H is zero. Note that, this condition is also consistent with the underlying integrable condition in these works from the apparent horizon.
Redshift of a photon emitted along the black hole horizon
Energy Technology Data Exchange (ETDEWEB)
Toporensky, A.V. [Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow (Russian Federation); Kazan Federal University, Kazan (Russian Federation); Zaslavskii, O.B. [Kazan Federal University, Kazan (Russian Federation); Kharkov V.N. Karazin National University, Department of Physics and Technology, Kharkov (Ukraine)
2017-03-15
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-Nordstroem 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. (orig.)
Classification of Near-Horizon Geometries of Extremal Black Holes
Directory of Open Access Journals (Sweden)
Hari K. Kunduri
2013-09-01
Full Text Available 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.
In search of meaningfulness: nostalgia as an antidote to boredom.
van Tilburg, Wijnand A P; Igou, Eric R; Sedikides, Constantine
2013-06-01
We formulated, tested, and supported, in 6 studies, a theoretical model according to which individuals use nostalgia as a way to reinject meaningfulness in their lives when they experience boredom. Studies 1-3 established that induced boredom causes increases in nostalgia when participants have the opportunity to revert to their past. Studies 4 and 5 examined search for meaning as a mediator of the effect of boredom on nostalgia. Specifically, Study 4 showed that search for meaning mediates the effect of state boredom on nostalgic memory content, whereas Study 5 demonstrated that search for meaning mediates the effect of dispositional boredom on dispositional nostalgia. Finally, Study 6 examined the meaning reestablishment potential of nostalgia during boredom: Nostalgia mediates the effect of boredom on sense of meaningfulness and presence of meaning in one's life. Nostalgia counteracts the meaninglessness that individuals experience when they are bored.
Concept Mapping Using Cmap Tools to Enhance Meaningful Learning
Cañas, Alberto J.; Novak, Joseph D.
Concept maps are graphical tools that have been used in all facets of education and training for organizing and representing knowledge. When learners build concept maps, meaningful learning is facilitated. Computer-based concept mapping software such as CmapTools have further extended the use of concept mapping and greatly enhanced the potential of the tool, facilitating the implementation of a concept map-centered learning environment. In this chapter, we briefly present concept mapping and its theoretical foundation, and illustrate how it can lead to an improved learning environment when it is combined with CmapTools and the Internet. We present the nationwide “Proyecto Conéctate al Conocimiento” in Panama as an example of how concept mapping, together with technology, can be adopted by hundreds of schools as a means to enhance meaningful learning.
International Nuclear Information System (INIS)
Ramavataram, S.
1991-01-01
In support of a continuing program of systematic evaluation of nuclear structure data, the National Nuclear Data Center maintains a complete computer file of references to the nuclear physics literature. Each reference is tagged by a keyword string, which indicates the kinds of data contained in the article. This master file of Nuclear Structure References (NSR) contains complete keyword indexes to literature published since 1969, with partial indexing of older references. Any reader who finds errors in the keyword descriptions is urged to report them to the National Nuclear Data Center so that the master NSR file can be corrected. In 1966, the first collection of Recent References was published as a separate issue of Nuclear Data Sheets. Every four months since 1970, a similar indexed bibliography to new nuclear experiments has been prepared from additions to the NSR file and published. Beginning in 1978, Recent References was cumulated annually, with the third issue completely superseding the two issues previously published during a given year. Due to publication policy changes, cumulation of Recent Reference was discontinued in 1986. The volume and issue number of all the cumulative issues published to date are given. NNDC will continue to respond to individual requests for special bibliographies on nuclear physics topics, in addition to those easily obtained from Recent References. If the required information is available from the keyword string, a reference list can be prepared automatically from the computer files. This service can be provided on request, in exchange for the timely communication of new nuclear physics results (e.g., preprints). A current copy of the NSR file may also be obtained in a standard format on magnetic tape from NNDC. Requests for special searches of the NSR file may also be directed to the National Nuclear Data Center
Early- versus Late-Onset Dysthymia: A Meaningful Clinical Distinction?
Sansone, Randy A.; Sansone, Lori A.
2009-01-01
In the current Diagnostic and Statistical Manual of Mental Disorders, dysthymic disorder is categorized as either early-onset or late-onset, based upon the emergence of symptoms before or after the age of 21, respectively. Does this diagnostic distinction have any meaningful clinical implications? In this edition of The Interface, we present empirical studies that have, within a single study, compared individuals with early-versus late-onset dysthymia. In this review, we found that, compared ...
Cool horizons lead to information loss
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.
Near-horizon brane-scan revived
International Nuclear Information System (INIS)
Duff, M.J.
2009-01-01
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 p+2 xS D-p-2 . 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
THE EVENT HORIZON OF SAGITTARIUS A*
International Nuclear Information System (INIS)
Broderick, Avery E.; Loeb, Abraham; Narayan, Ramesh
2009-01-01
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.
THE EVENT HORIZON OF SAGITTARIUS A*
Energy Technology Data Exchange (ETDEWEB)
Broderick, Avery E [Canadian Institute for Theoretical Astrophysics, 60 St. George St., Toronto, ON M5S 3H8 (Canada); Loeb, Abraham; Narayan, Ramesh [Institute for Theory and Computation, Harvard University, Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)
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.
Energy and information near black hole horizons
International Nuclear Information System (INIS)
Freivogel, Ben
2014-01-01
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
Gribov's horizon and the ghost dressing function
International Nuclear Information System (INIS)
Boucaud, Ph.; Leroy, J. P.; Le Yaouanc, A.; Micheli, J.; Pene, O.; Rodriguez-Quintero, J.
2009-01-01
We study a relation recently derived by K. Kondo at zero momentum between the Zwanziger's horizon function, the ghost dressing function and Kugo's functions u and w. We agree with this result as far as bare quantities are considered. However, assuming the validity of the horizon gap equation, we argue that the solution w(0)=0 is not acceptable since it would lead to a vanishing renormalized ghost dressing function. On the contrary, when the cutoff goes to infinity, u(0)→∞, w(0)→-∞ such that u(0)+w(0)→-1. Furthermore w and u are not multiplicatively renormalizable. Relaxing the gap equation allows w(0)=0 with u(0)→-1. In both cases the bare ghost dressing function, F(0,Λ), goes logarithmically to infinity at infinite cutoff. We show that, although the lattice results provide bare results not so different from the F(0,Λ)=3 solution, this is an accident due to the fact that the lattice cutoffs lie in the range 1-3 GeV -1 . We show that the renormalized ghost dressing function should be finite and nonzero at zero momentum and can be reliably estimated on the lattice up to powers of the lattice spacing; from published data on a 80 4 lattice at β=5.7 we obtain F R (0,μ=1.5 GeV)≅2.2.
Radiation from quantum weakly dynamical horizons in loop quantum gravity.
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.
Meaningful Use of a Confidential Adolescent Patient Portal.
Thompson, Lindsay A; Martinko, Thomas; Budd, Pamela; Mercado, Rebeccah; Schentrup, Anzeela M
2016-02-01
To design and evaluate the usage of an adolescent patient portal specifically adapted for adolescent health care needs that also satisfied institutional meaningful use guidelines regarding electronic health records. Key stakeholders at one academic health care center adopted an online portal and opted to designate a patient portal specifically for adolescents to maximize confidentiality in compliance with state privacy laws. This study analyzed aggregate electronic health record data of adolescents' (ages 12-17.9 years) uptake, usage, and functionality of this portal and compared it to parent portal usage for younger children (ages 0-11 years). Differences in means were calculated using paired t tests. The portal was used similarly between parents of young children and adolescents, with almost 1,000 enrollees in each group from September 1, 2012 to March 31, 2015. There were no gender differences in enrollment. Adolescents were less likely than parents of younger children to review appointments (73% vs. 85%), laboratory tests (67% vs. 79%), problem lists (40% vs. 78%), or allergies (45% vs. 77%, all p values adolescents sent 1,397 confidential messages. Institutional decisions for implementing meaningful use requirements can align with goals of adolescent health. Patient portals can enhance adolescent health care quality and adolescents readily use a confidential portal. Implementation of meaningful use requirements should be checked against adolescent health care needs to maximize confidentiality and promote health communication. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.
New Worlds, New Horizons in Astronomy and Astrophysics
National Research Council Canada - National Science Library
2010-01-01
.... Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysic...
QFT holography near the horizon of Schwarzschild-like spacetimes
Moretti, Valter; Pinamonti, Nicola
2003-01-01
It is argued that free QFT can be defined on the event horizon of a Schwarzschild-like spacetime and that this theory is unitarily and algebraically equivalent to QFT in the bulk (near the horizon). Under that unitary equivalence the bulk hidden SL(2,R) symmetry found in a previous work becomes manifest on the event horizon, it being induced by a group of horizon diffeomorphisms. The class of generators of that group can be enlarged to include a full Virasoro algebra of fields which are defin...
Event boundaries and anaphoric reference.
Thompson, Alexis N; Radvansky, Gabriel A
2016-06-01
The current study explored the finding that parsing a narrative into separate events impairs anaphor resolution. According to the Event Horizon Model, when a narrative event boundary is encountered, a new event model is created. Information associated with the prior event model is removed from working memory. So long as the event model containing the anaphor referent is currently being processed, this information should still be available when there is no narrative event boundary, even if reading has been disrupted by a working-memory-clearing distractor task. In those cases, readers may reactivate their prior event model, and anaphor resolution would not be affected. Alternatively, comprehension may not be as event oriented as this account suggests. Instead, any disruption of the contents of working memory during comprehension, event related or not, may be sufficient to disrupt anaphor resolution. In this case, reading comprehension would be more strongly guided by other, more basic language processing mechanisms and the event structure of the described events would play a more minor role. In the current experiments, participants were given stories to read in which we included, between the anaphor and its referent, either the presence of a narrative event boundary (Experiment 1) or a narrative event boundary along with a working-memory-clearing distractor task (Experiment 2). The results showed that anaphor resolution was affected by narrative event boundaries but not by a working-memory-clearing distractor task. This is interpreted as being consistent with the Event Horizon Model of event cognition.
Directory of Open Access Journals (Sweden)
Dimitrios Dadakas
2016-12-01
Full Text Available The stock beta coefficient literature extensively discusses the proper methods for the estimation of beta as well as its use in asset valuation. However, there are fewer references with respect to the appropriate time horizon that investors should utilize when evaluating the risk-return relationship of a stock. We examine the appropriate time horizon for beta estimation, differentiating our results by sector according to the Industry Classification Benchmark. We employ data from the NYSE and estimate varying lengths of beta employing data from 30 to 250 trading days. The constructed beta series is then examined for the presence of breaks using the endogenous structural break literature. Results show evidence against the use of betas that employ more than 90 trading days of data provisional to the sector under study.
Quantum field theory, horizons and thermodynamics
International Nuclear Information System (INIS)
Sciama, D.W.; Candelas, P.; Deutsch, D.
1981-01-01
The aim of the article is to obtain an intuitive understanding of the recently explored deep connections between thermal physics, quantum field theory and general relativity. A special case in which a detector moves with constant acceleration through a quantum vacuum is examined to clarify the fact that such a detector becomes thermally excited, with a temperature proportional to its acceleration. An elementary physical explanation of this fundamental result is provided. The uniformly accelerated observer finds his space-time manifold bounded by an event horizon and so realizes a 'model' black hole. Real black holes also have thermal properties when quantum effects are taken into account; these are described and the correspondences with the accelerated case are pointed out. In particular, an elementary account is given of the thermal Hawking radiation emitted by the black holes formed by collapsed stars. (author)
CERN encourages girls to "expand their horizons"
François Briard
2015-01-01
On 14 November, CERN took part for the fourth time in "Élargis tes horizons" (see here), a conference organised every two years at Geneva University for girls from the local region aged 11 to 14 aiming to encourage them to take up studies and careers in the scientific and technical domains. Claude Sanz (left), a fellow in the EN Department, explaining to three girls how to build a particle accelerator in a salad bowl. This year, young physicists and engineers from ATLAS and CMS ran three workshops: "Seeing the invisible using a cloud chamber", "Great cold fun and treats with liquid nitrogen" and "Build your own accelerator in a salad bowl!" CERN was also represented at the Forum de Découverte, represented by the Diversity Office and the Medialab team, presenting the "Higgnite" interactive experiment, which illustrates the principle of the Higgs field. More...
Lovelock black holes with maximally symmetric horizons
Energy Technology Data Exchange (ETDEWEB)
Maeda, Hideki; Willison, Steven; Ray, Sourya, E-mail: hideki@cecs.cl, E-mail: willison@cecs.cl, E-mail: ray@cecs.cl [Centro de Estudios CientIficos (CECs), Casilla 1469, Valdivia (Chile)
2011-08-21
We investigate some properties of n( {>=} 4)-dimensional spacetimes having symmetries corresponding to the isometries of an (n - 2)-dimensional maximally symmetric space in Lovelock gravity under the null or dominant energy condition. The well-posedness of the generalized Misner-Sharp quasi-local mass proposed in the past study is shown. Using this quasi-local mass, we clarify the basic properties of the dynamical black holes defined by a future outer trapping horizon under certain assumptions on the Lovelock coupling constants. The C{sup 2} vacuum solutions are classified into four types: (i) Schwarzschild-Tangherlini-type solution; (ii) Nariai-type solution; (iii) special degenerate vacuum solution; and (iv) exceptional vacuum solution. The conditions for the realization of the last two solutions are clarified. The Schwarzschild-Tangherlini-type solution is studied in detail. We prove the first law of black-hole thermodynamics and present the expressions for the heat capacity and the free energy.
Horizons of semiclassical black holes are cold
International Nuclear Information System (INIS)
Brustein, Ram; Medved, A.J.M.
2014-01-01
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_c_o_h at any given time is parametrically smaller than the total number of the Hawking particles N_t_o_t_a_l emitted during the lifetime of the BH. We find that N_c_o_h 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_c_o_h 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_c_o_h. 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_t_o_t_a_l
THERMAL CONDUCTIVITY OF THE POTENTIAL REPOSITORY HORIZON
Energy Technology Data Exchange (ETDEWEB)
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.
Horizons of semiclassical black holes are cold
Energy Technology Data Exchange (ETDEWEB)
Brustein, Ram [Department of Physics, Ben-Gurion University,Beer-Sheva 84105 (Israel); CAS, Ludwig-Maximilians-Universität München,80333 München (Germany); Medved, A.J.M. [Department of Physics & Electronics, Rhodes University,Grahamstown 6140 (South Africa)
2014-06-10
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{sub coh} at any given time is parametrically smaller than the total number of the Hawking particles N{sub total} emitted during the lifetime of the BH. We find that N{sub 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{sub 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{sub 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{sub total}.
Are there meaningful individual differences in temporal inconsistency in self-reported personality?
Soubelet, Andrea; Salthouse, Timothy A; Oishi, Shigehiro
2014-11-01
The current project had three goals. The first was to examine whether it is meaningful to refer to across-time variability in self-reported personality as an individual differences characteristic. The second was to investigate whether negative affect was associated with variability in self-reported personality, while controlling for mean levels, and correcting for measurement errors. The third goal was to examine whether variability in self-reported personality would be larger among young adults than among older adults, and whether the relation of variability with negative affect would be stronger at older ages than at younger ages. Two moderately large samples of participants completed the International Item Pool Personality questionnaire assessing the Big Five personality dimensions either twice or thrice, in addition to several measures of negative affect. Results were consistent with the hypothesis that within-person variability in self-reported personality is a meaningful individual difference characteristic. Some people exhibited greater across-time variability than others after removing measurement error, and people who showed temporal instability in one trait also exhibited temporal instability across the other four traits. However, temporal variability was not related to negative affect, and there was no evidence that either temporal variability or its association with negative affect varied with age.
Association between clinically meaningful behavior problems and overweight in children.
Lumeng, Julie C; Gannon, Kate; Cabral, Howard J; Frank, Deborah A; Zuckerman, Barry
2003-11-01
To determine whether there is a relationship between clinically meaningful behavior problems and concurrent and future overweight in 8- to 11-year-old children. 1998 National Longitudinal Survey of Youth interview data for 8- to 11-year-old children and their mothers were analyzed. A Behavior Problems Index score >90th percentile was considered clinically meaningful. Child overweight was defined as a body mass index (BMI) >or=95th percentile for age and sex. Multiple logistic regression was used to control for potential confounders (selected a priori): child's sex, race, use of behavior-modifying medication, history of academic retention, and hours of television per day; maternal obesity, smoking status, marital status, education, and depressive symptoms; family poverty status; and Home Observation for Measurement of the Environment-Short Form (HOME-SF) cognitive stimulation score. In an attempt to elucidate temporal sequence, a second analysis was conducted with a subsample of normal-weight children who became overweight between 1996 and 1998 while controlling for BMI z score in 1996. The sample included 755 mother-child pairs. Of the potential confounding variables, race, maternal obesity, academic grade retention, maternal education, poverty status, and HOME-SF cognitive stimulation score acted as joint confounders, altering the relationship between behavior problems and overweight in the multiple logistic regression model. With these covariates in the final model, behavior problems were independently associated with concurrent child overweight (adjusted odds ratio: 2.95; 95% confidence interval: 1.34-6.49). The relationship was strengthened in the subsample of previously normal-weight children, with race, maternal obesity, HOME-SF cognitive stimulation score, and 1996 BMI z score acting as confounders (adjusted odds ratio: 5.23; 95% confidence interval: 1.37-19.9). Clinically meaningful behavior problems in 8- to 11-year-old children were independently
Conference Offers Girls Opportunity to Expand Career Horizons
Offers Girls Opportunity to Expand Career Horizons For more information contact: e:mail: Public Affairs Golden, Colo., Feb. 11, 1997 -- Expanding Your Horizons, a conference for girls grades 6 - 9 and Employed Women, Girls Incorporated of Metro Denver, King Soopers, McDonalds, the TCI Adult Program and the
Thermal and nonthermal particle production without event horizons
International Nuclear Information System (INIS)
Sanchez, N.
1979-01-01
Usually, particle production in accelerated frames is discussed in connection with the presence of event horizons and with a planckian spectrum. Accelerated frames without event horizons, where particle production takes place with thermal as well as nonthermal distributions, are constructed. (Auth.)
Nearly extremal apparent horizons in simulations of merging black holes
Lovelace, Geoffrey; Scheel, Mark; Owen, Robert; Giesler, Matthew; Katebi, Reza; Szilagyi, Bela; Chu, Tony; Demos, Nicholas; Hemberger, Daniel; Kidder, Lawrence; Pfeiffer, Harald; Afshari, Nousha; SXS Collaboration
2015-04-01
The spin S of a Kerr black hole is bounded by the surface area A of its apparent horizon: 8 πS A and e0 > 1 , but these surfaces are always surrounded by apparent horizons with 8 πS < A and e0 < 1 .
Measuring meaningful learning in the undergraduate chemistry laboratory
Galloway, Kelli R.
The undergraduate chemistry laboratory has been an essential component in chemistry education for over a century. The literature includes reports on investigations of singular aspects laboratory learning and attempts to measure the efficacy of reformed laboratory curriculum as well as faculty goals for laboratory learning which found common goals among instructors for students to learn laboratory skills, techniques, experimental design, and to develop critical thinking skills. These findings are important for improving teaching and learning in the undergraduate chemistry laboratory, but research is needed to connect the faculty goals to student perceptions. This study was designed to explore students' ideas about learning in the undergraduate chemistry laboratory. Novak's Theory of Meaningful Learning was used as a guide for the data collection and analysis choices for this research. Novak's theory states that in order for meaningful learning to occur the cognitive, affective, and psychomotor domains must be integrated. The psychomotor domain is inherent in the chemistry laboratory, but the extent to which the cognitive and affective domains are integrated is unknown. For meaningful learning to occur in the laboratory, students must actively integrate both the cognitive domain and the affective domains into the "doing" of their laboratory work. The Meaningful Learning in the Laboratory Instrument (MLLI) was designed to measure students' cognitive and affective expectations and experiences within the context of conducting experiments in the undergraduate chemistry laboratory. Evidence for the validity and reliability of the data generated by the MLLI were collected from multiple quantitative studies: a one semester study at one university, a one semester study at 15 colleges and universities across the United States, and a longitudinal study where the MLLI was administered 6 times during two years of general and organic chemistry laboratory courses. Results from
Wider horizons, wiser choices: horizon scanning for public health protection and improvement.
Urquhart, Graham J; Saunders, Patrick
2017-06-01
Systematic continuous thinking about the future helps organizations, professions and communities to both prepare for, and shape, the future. This becomes ever more critical given the accelerating rate at which new data emerge, and in some cases uncertainties around their reliability and interpretation. Businesses with the capability to filter and analyse vast volumes of data to create knowledge and insights requiring action have a competitive advantage. Similarly Government and the public sector, including public health can be more effective and efficient through the early identification of emerging issues (both threats and opportunities). Horizon scanning approaches, and the use of resulting intelligence related to health protection and improvement were reviewed. Public health horizon scanning systems have to date focussed on health technologies and infectious diseases. While these have been successful there is a major gap in terms of non-infectious hazards and health improvement. Any system to meet this need must recognize the changed environment for delivering front line public health services and the critical role of local authorities and the local democratic process. This presents opportunities and challenges and this paper explores those dynamics describing an existing environment and health horizon scanning system which could readily and rapidly be re-engineered to provide a national service. © The Author 2016. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Cosmological horizons as new examples of the membrane paradigm
International Nuclear Information System (INIS)
Wang, Tower
2015-01-01
In this paper we aim to provide new examples of the application and the generality of the membrane paradigm. The membrane paradigm is a formalism for studying the event horizon of black holes. After analyzing it with some technical details and realizing it in the Reissner–Nordström black hole, we apply the paradigm to cosmological horizons, first to the pure de Sitter horizon, and then to the trapping horizon of the Friedmann–Lemaître–Robertson–Walker Universe. In the latter case, the cosmological stretched horizon is oblique, thus the running of the renormalization parameter is nonzero in the timelike direction and gives a correction to the membrane pressure. In this paradigm, the cosmological equations come from continuity equations of the membrane fluid and the bulk fluid respectively. (paper)
An integrative approach to inferring biologically meaningful gene modules
Directory of Open Access Journals (Sweden)
Wang Kai
2011-07-01
Full Text Available Abstract Background The ability to construct biologically meaningful gene networks and modules is critical for contemporary systems biology. Though recent studies have demonstrated the power of using gene modules to shed light on the functioning of complex biological systems, most modules in these networks have shown little association with meaningful biological function. We have devised a method which directly incorporates gene ontology (GO annotation in construction of gene modules in order to gain better functional association. Results We have devised a method, Semantic Similarity-Integrated approach for Modularization (SSIM that integrates various gene-gene pairwise similarity values, including information obtained from gene expression, protein-protein interactions and GO annotations, in the construction of modules using affinity propagation clustering. We demonstrated the performance of the proposed method using data from two complex biological responses: 1. the osmotic shock response in Saccharomyces cerevisiae, and 2. the prion-induced pathogenic mouse model. In comparison with two previously reported algorithms, modules identified by SSIM showed significantly stronger association with biological functions. Conclusions The incorporation of semantic similarity based on GO annotation with gene expression and protein-protein interaction data can greatly enhance the functional relevance of inferred gene modules. In addition, the SSIM approach can also reveal the hierarchical structure of gene modules to gain a broader functional view of the biological system. Hence, the proposed method can facilitate comprehensive and in-depth analysis of high throughput experimental data at the gene network level.
Myasthenia Gravis Impairment Index: Responsiveness, meaningful change, and relative efficiency.
Barnett, Carolina; Bril, Vera; Kapral, Moira; Kulkarni, Abhaya V; Davis, Aileen M
2017-12-05
To study responsiveness and meaningful change of the Myasthenia Gravis Impairment Index (MGII) and its relative efficiency compared to other measures. We enrolled 95 patients receiving prednisone, IV immunoglobulin (IVIg), or plasma exchange (PLEX) and 54 controls. Patients were assessed with the MGII and other measures-including the Quantitative Myasthenia Gravis Score, Myasthenia Gravis Composite, and Myasthenia Gravis Activities of Daily Living-at baseline and 3-4 weeks after treatment. Statistical markers of responsiveness included between-groups and within-group differences, and we estimated the relative efficiency of the MGII compared to other measures. Patient-meaningful change was assessed with an anchor-based method, using the patient's impression of change. We determined the minimal detectable change (MDC) and the minimal important difference (MID) at the group and individual level. Treated patients had a higher change in MGII scores than controls (analysis of covariance p 1 favoring the MGII. The MGII demonstrated responsiveness to prednisone, IVIg, and PLEX in patients with myasthenia. There is a differential response in ocular and generalized symptoms to type of therapy. The MGII has higher relative efficiency than comparison measures and is viable for use in clinical trials. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.
Horizon shells and BMS-like soldering transformations
Energy Technology Data Exchange (ETDEWEB)
Blau, Matthias [Albert Einstein Center for Fundamental Physics,Institute for Theoretical Physics, University of Bern,Sidlerstrasse 5, 3012 Bern (Switzerland); O’Loughlin, Martin [University of Nova Gorica,Vipavska 13, 5000 Nova Gorica (Slovenia)
2016-03-07
We revisit the theory of null shells in general relativity, with a particular emphasis on null shells placed at horizons of black holes. We study in detail the considerable freedom that is available in the case that one solders two metrics together across null hypersurfaces (such as Killing horizons) for which the induced metric is invariant under translations along the null generators. In this case the group of soldering transformations turns out to be infinite dimensional, and these solderings create non-trivial horizon shells containing both massless matter and impulsive gravitational wave components. We also rephrase this result in the language of Carrollian symmetry groups. To illustrate this phenomenon we discuss in detail the example of shells on the horizon of the Schwarzschild black hole (with equal interior and exterior mass), uncovering a rich classical structure at the horizon and deriving an explicit expression for the general horizon shell energy-momentum tensor. In the special case of BMS-like soldering supertranslations we find a conserved shell-energy that is strikingly similar to the standard expression for asymptotic BMS supertranslation charges, suggesting a direct relation between the physical properties of these horizon shells and the recently proposed BMS supertranslation hair of a black hole.
Does the black hole shadow probe the event horizon geometry?
Cunha, Pedro V. P.; Herdeiro, Carlos A. R.; Rodriguez, Maria J.
2018-04-01
There is an exciting prospect of obtaining the shadow of astrophysical black holes (BHs) in the near future with the Event Horizon Telescope. As a matter of principle, this justifies asking how much one can learn about the BH horizon itself from such a measurement. Since the shadow is determined by a set of special photon orbits, rather than horizon properties, it is possible that different horizon geometries yield similar shadows. One may then ask how sensitive is the shadow to details of the horizon geometry? As a case study, we consider the double Schwarzschild BH and analyze the impact on the lensing and shadows of the conical singularity that holds the two BHs in equilibrium—herein taken to be a strut along the symmetry axis in between the two BHs. Whereas the conical singularity induces a discontinuity of the scattering angle of photons, clearly visible in the lensing patterns along the direction of the strut's location, it produces no observable effect on the shadows, whose edges remain everywhere smooth. The latter feature is illustrated by examples including both equal and unequal mass BHs. This smoothness contrasts with the intrinsic geometry of the (spatial sections of the) horizon of these BHs, which is not smooth, and provides a sharp example on how BH shadows are insensitive to some horizon geometry details. This observation, moreover, suggests that for the study of their shadows, this static double BH system may be an informative proxy for a dynamical binary.
Perturbative string thermodynamics near black hole horizons
International Nuclear Information System (INIS)
Mertens, Thomas G.; Verschelde, Henri; Zakharov, Valentin I.
2015-01-01
We provide further computations and ideas to the problem of near-Hagedorn string thermodynamics near (uncharged) black hole horizons, building upon our earlier work http://dx.doi.org/10.1007/JHEP03(2014)086. The relevance of long strings to one-loop black hole thermodynamics is emphasized. We then provide an argument in favor of the absence of α ′ -corrections for the (quadratic) heterotic thermal scalar action in Rindler space. We also compute the large k limit of the cigar orbifold partition functions (for both bosonic and type II superstrings) which allows a better comparison between the flat cones and the cigar cones. A discussion is made on the general McClain-Roth-O’Brien-Tan theorem and on the fact that different torus embeddings lead to different aspects of string thermodynamics. The black hole/string correspondence principle for the 2d black hole is discussed in terms of the thermal scalar. Finally, we present an argument to deal with arbitrary higher genus partition functions, suggesting the breakdown of string perturbation theory (in g s ) to compute thermodynamical quantities in black hole spacetimes.
New geometries for black hole horizons
Energy Technology Data Exchange (ETDEWEB)
Armas, Jay [Physique Théorique et Mathématique,Université Libre de Bruxelles and International Solvay Institutes, ULB-Campus Plaine CP231, B-1050 Brussels (Belgium); Blau, Matthias [Albert Einstein Center for Fundamental Physics, University of Bern,Sidlerstrasse 5, 3012 Bern (Switzerland)
2015-07-10
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.
Grids Today, Clouds on the Horizon
Shiers, J
2008-01-01
By the time of CCP 2008, the worldâs largest scientific machine â the Large Hadron Collider â should have been cooled down to its operational temperature of below 20K and injection tests should have started. Collisions of proton beams at 5 + 5 TeV are expected within one to two months of the initial tests, with data taking at design energy (7 + 7 TeV) now foreseen for 2009. In order to process the data from this world machine, we have put our âﾜHiggs in one basketâ â that of Grid computing. After many years of preparation, 2008 has seen a final âﾜCommon Computing Readiness Challengeâ (CCRCâ08) â aimed at demonstrating full readiness for 2008 data taking, processing and analysis. By definition, this relies on a worldâwide production Grid infrastructure. But change â as always â is on the horizon. The current funding model for Grids â which in Europe has been through 3 generations of EGEE projects, together with related projects in other part...
Grids Today, Clouds on the Horizon
Shiers, J
2008-01-01
By the time of CCP 2008, the largest scientific machine in the world -â the Large Hadron Collider -â had been cooled down as scheduled to its operational temperature of below 2 degrees Kelvin and injection tests were starting. Collisions of proton beams at 5 + 5 TeV were expected within one to two months of the initial tests, with data taking at design energy (7 + 7 TeV) foreseen for 2009. In order to process the data from this world machine, we have put our "Higgs in one basket" -â that of Grid computing. After many years of preparation, 2008 saw a final "Common Computing Readiness Challenge" (CCRCâ08) -â aimed at demonstrating full readiness for 2008 data taking, processing and analysis. By definition, this relied on a world-wide production Grid infrastructure. But change â as always â is on the horizon. The current funding model for Grids â which in Europe has been through 3 generations of EGEE projects, together with related projects in other parts of the world, inc...
Grid today, clouds on the horizon
Shiers, Jamie
2009-01-01
By the time of CCP 2008, the largest scientific machine in the world – the Large Hadron Collider – had been cooled down as scheduled to its operational temperature of below 2 degrees Kelvin and injection tests were starting. Collisions of proton beams at 5+5 TeV were expected within one to two months of the initial tests, with data taking at design energy (7+7 TeV) foreseen for 2009. In order to process the data from this world machine, we have put our “Higgs in one basket” – that of Grid computing [The Worldwide LHC Computing Grid (WLCG), in: Proceedings of the Conference on Computational Physics 2006 (CCP 2006), vol. 177, 2007, pp. 219–223]. After many years of preparation, 2008 saw a final “Common Computing Readiness Challenge” (CCRC'08) – aimed at demonstrating full readiness for 2008 data taking, processing and analysis. By definition, this relied on a world-wide production Grid infrastructure. But change – as always – is on the horizon. The current funding model for Grids – which...
Measuring Item Fill-Rate Performance in a Finite Horizon
Douglas J. Thomas
2005-01-01
The standard treatment of fill rate relies on stationary and serially independent demand over an infinite horizon. Even if demand is stationary, managers are held accountable for performance over a finite horizon. In a finite horizon, the fill rate is a random variable. Studying the distribution is relevant because a vendor may be subject to financial penalty if she fails to achieve her target fill rate over a specified finite period. It is known that for a zero lead time, base-stock model, t...
Thermodynamics of event horizons in (2+1)-dimensional gravity
International Nuclear Information System (INIS)
Reznik, B.
1992-01-01
Although gravity in 2+1 dimensions is very different in nature from gravity in 3+1 dimensions, it is shown that the laws of thermodynamics for event horizons can be manifested also for (2+1)-dimensional gravity. The validity of the classical laws of horizon mechanics is verified in general and exemplified for the (2+1)-dimensional analogues of Reissner-Nordstroem and Schwarzschild--de Sitter spacetimes. We find that the entropy is given by 1/4L, where L is the length of the horizon. A consequence of having consistent thermodynamics is that the second law fixes the sign of Newton's constant to be positive
Quantum black holes: the event horizon as a fuzzy sphere
International Nuclear Information System (INIS)
Dolan, Brian P.
2005-01-01
Modeling the event horizon of a black hole by a fuzzy sphere leads us to modify some suggestions in the literature concerning black hole mass spectra. We derive a formula for the mass spectrum of quantum black holes in terms of four integers which define the area, angular momentum, electric and magnetic charge of the black hole. Although the event horizon becomes a commutative sphere in the classical limit a vestige of the quantum theory still persists in that the event horizon stereographically projects onto the non-commutative plane. We also suggest how the classical bounds on extremal black holes might be modified in the quantum theory. (author)
Quantum correlations through event horizons: Fermionic versus bosonic entanglement
International Nuclear Information System (INIS)
Martin-Martinez, Eduardo; Leon, Juan
2010-01-01
We disclose the behavior of quantum and classical correlations among all the different spatial-temporal regions of a space-time with an event horizon, comparing fermionic with bosonic fields. We show the emergence of conservation laws for entanglement and classical correlations, pointing out the crucial role that statistics plays in the information exchange (and more specifically, the entanglement tradeoff) across horizons. The results obtained here could shed new light on the problem of information behavior in noninertial frames and in the presence of horizons, giving better insight into the black-hole information paradox.
Apparent violation of the principle of equivalence and Killing horizons
International Nuclear Information System (INIS)
Zimmerman, R.L.; Farhoosh, H.; Oregon Univ., Eugene
1980-01-01
By means of the principle of equivalence it is deduced that the qualitative behavior of the Schwarzschild horizon about a uniformly accelerating particle. This result is confirmed for an exact solution of a uniformly accelerating object in the limit of small accelerations. For large accelerations the Schwarzschild horizon appears to violate the qualitative behavior established via the principle of equivalence. When similar arguments are extended to an observable such as the red shift between two observers, there is no departure from the results expected from the principle of equivalence. The resolution of the paradox is brought about by a compensating effect due to the Rindler horizon. (author)
The measurement of water scarcity: Defining a meaningful indicator.
Damkjaer, Simon; Taylor, Richard
2017-09-01
Metrics of water scarcity and stress have evolved over the last three decades from simple threshold indicators to holistic measures characterising human environments and freshwater sustainability. Metrics commonly estimate renewable freshwater resources using mean annual river runoff, which masks hydrological variability, and quantify subjectively socio-economic conditions characterising adaptive capacity. There is a marked absence of research evaluating whether these metrics of water scarcity are meaningful. We argue that measurement of water scarcity (1) be redefined physically in terms of the freshwater storage required to address imbalances in intra- and inter-annual fluxes of freshwater supply and demand; (2) abandons subjective quantifications of human environments and (3) be used to inform participatory decision-making processes that explore a wide range of options for addressing freshwater storage requirements beyond dams that include use of renewable groundwater, soil water and trading in virtual water. Further, we outline a conceptual framework redefining water scarcity in terms of freshwater storage.
School nurse evaluations: making the process meaningful and motivational.
McDaniel, Kathryn H; Overman, Muriel; Guttu, Martha; Engelke, Martha Keehner
2013-02-01
The professional standards of school nursing practice provide a framework to help school nurses focus on their unique mission of promoting health and academic achievement for all students. Without the standards, the nurse's role can become task oriented and limited in scope. By using an evaluation tool that reflects the standards, nurses not only become aware and begin to understand the standards; they also become directly accountable for meeting them. In addition, developing an evaluation process based on the standards of school nurse practice increases the visibility of school nurses and helps school administrators understand the role of the school nurse. This article describes how one school district integrated the scope and standards of school nursing into the job description and performance evaluation of the nurse. The process which is used to complete the evaluation in a manner that is meaningful and motivational to the school nurse is described.
Writing more informative letters of reference.
Wright, Scott M; Ziegelstein, Roy C
2004-05-01
Writing a meaningful and valuable letter of reference is not an easy task. Several factors influence the quality of any letter of reference. First, the accuracy and reliability of the writer's impressions and judgment depend on how well he knows the individual being described. Second, the writer's frame of reference, which is determined by the number of persons at the same level that he has worked with, will impact the context and significance of his beliefs and estimations. Third, the letter-writing skills of the person composing the letter will naturally affect the letter. To support the other components of a candidate's application, a letter of reference should provide specific examples of how an individual's behavior or attitude compares to a reference group and should assess "intangibles" that are hard to glean from a curriculum vitae or from test scores. This report offers suggestions that should help physicians write more informative letters of reference.
A Cardy-like formula for rotating black holes with planar horizon
Energy Technology Data Exchange (ETDEWEB)
Gaete, Moisés Bravo [Facultad de Ciencias Básicas, Universidad Católica del Maule,Casilla 617, Talca (Chile); Guajardo, Luis; Hassaïne, Mokhtar [Instituto de Matemática y Fisica, Universidad de Talca,Casilla 747, Talca (Chile)
2017-04-18
We show that the semiclassical entropy of D−dimensional rotating (an)isotropic black holes with planar horizon can be successfully computed according to a Cardy-like formula. This formula does not refer to any central charges but instead involves the vacuum energy which is identified with a gravitational bulk soliton. The soliton is obtained from the non-rotating black hole solution by means of a double analytic continuation. The robustness of the Cardy-like formula is tested with numerous and varied examples, including AdS, Lifshitz and hyperscaling violation planar black holes.
Fermions tunneling from apparent horizon of FRW universe
International Nuclear Information System (INIS)
Li Ran; Ren Jirong; Shi Dunfu
2009-01-01
In the paper [R.-G. Cai, L.-M. Cao, Y.-P. Hu, (arXiv: 0809.1554)], the scalar particles' Hawking radiation from the apparent horizon of Friedmann-Robertson-Walker (FRW) universe was investigated by using the tunneling formalism. They obtained the Hawking temperature associated with the apparent horizon, which was extensively applied in investigating the relationship between the first law of thermodynamics and Friedmann equations. In this Letter, we calculate fermions' Hawking radiation from the apparent horizon of FRW universe via tunneling formalism. Applying WKB approximation to the general covariant Dirac equation in FRW spacetime background, the radiation spectrum and Hawking temperature of apparent horizon are correctly recovered, which supports the arguments presented in the paper [R.-G. Cai, L.-M. Cao, Y.-P. Hu, (arXiv: 0809.1554)
Dividend taxation in an infinite-horizon general equilibrium model
Pham, Ngoc-Sang
2017-01-01
We consider an infinite-horizon general equilibrium model with heterogeneous agents and financial market imperfections. We investigate the role of dividend taxation on economic growth and asset price. The optimal dividend taxation is also studied.
Research Ship New Horizon Underway Meteorological Data, Quality Controlled
National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship New Horizon Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...
Proposed cuts to Horizon 2020 are short-sighted
2015-01-01
When the latest incarnation of Europe’s framework programme for science funding, Horizon 2020, was announced, it was to great acclaim. Horizon 2020 builds on the already considerable success of its forerunners, which have made international research at the European level a reality and have contributed greatly to European competitiveness on the world stage. We at CERN have benefited considerably, through projects that have enabled us to build on CERN’s core competencies to develop science at the grass-roots level across the continent. Horizon 2020 is more ambitious and more streamlined than its predecessors, and, funded at the level of €70 billion over seven years, it is potentially transformative. All of which makes the Commission’s plan to raid the Horizon 2020 budget to the tune of €2.7 billion rather incomprehensible. Keen to stimulate Europe’s economies, Commission President Jean-Claude Juncker has proposed a €21 billio...
The absence of horizon in black-hole formation
Energy Technology Data Exchange (ETDEWEB)
Ho, Pei-Ming, E-mail: pmho@phys.ntu.edu.tw
2016-08-15
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.
The absence of horizon in black-hole formation
Directory of Open Access Journals (Sweden)
Pei-Ming Ho
2016-08-01
Full Text Available 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.
The absence of horizon in black-hole formation
International Nuclear Information System (INIS)
Ho, Pei-Ming
2016-01-01
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.
HORIZON 2020 - Project SITEX-II
International Nuclear Information System (INIS)
Nachmilner, L.
2016-01-01
In the mid of 2015 a coordination action SITEX-II was initiated within the EC programme Horizon 2020. It aims at implementing in practice activities along with the interaction models issued by the SITEX project (carried out within FP7 programme in 2012-13), in view of developing an Expertise function network. This network is expected to ensure sustainable capacity of developing and coordination joint and harmonised activities related to the independent technical expertise in the field of safety of deep geological disposal of radioactive waste. SITEX-II tasks include: • The definition of the Strategic Research Agenda (SRA) based on the common R orientations defined by SITEX, the definition of ToR for the implementation of specific topics of from the SRA, and the interaction with IGD-TP and other external entities mandated to implement research on radioactive waste disposal regarding the potential setting up of a respective European Joint Programming; • The production of a guidance on the technical review of the safety case at its different phases of development, fostering a common understanding on the interpretation and proper implementation of safety requirements for developing, operating and closing a geological repository and on then verification of compliance with these requirements; • The commitment of a Civil Society (CS) in the definition of the SRA mentioned above, considering the expectations and technical questions to be considered when developing R for the purpose of Expert function. Close interactions between experts conducting the review work and CS representatives will enhance establishing the safety culture and, more globally, proposing governance patterns with CS in the framework of geological disposal; • The preparation of the ‚administrative‘ framework for creating a sustainable network of Technical Safety Organisations from EU members states by addressing the legal organisational and management aspects. (author)
Grid today, clouds on the horizon
Shiers, Jamie
2009-04-01
By the time of CCP 2008, the largest scientific machine in the world - the Large Hadron Collider - had been cooled down as scheduled to its operational temperature of below 2 degrees Kelvin and injection tests were starting. Collisions of proton beams at 5+5 TeV were expected within one to two months of the initial tests, with data taking at design energy ( 7+7 TeV) foreseen for 2009. In order to process the data from this world machine, we have put our "Higgs in one basket" - that of Grid computing [The Worldwide LHC Computing Grid (WLCG), in: Proceedings of the Conference on Computational Physics 2006 (CCP 2006), vol. 177, 2007, pp. 219-223]. After many years of preparation, 2008 saw a final "Common Computing Readiness Challenge" (CCRC'08) - aimed at demonstrating full readiness for 2008 data taking, processing and analysis. By definition, this relied on a world-wide production Grid infrastructure. But change - as always - is on the horizon. The current funding model for Grids - which in Europe has been through 3 generations of EGEE projects, together with related projects in other parts of the world, including South America - is evolving towards a long-term, sustainable e-infrastructure, like the European Grid Initiative (EGI) [The European Grid Initiative Design Study, website at http://web.eu-egi.eu/]. At the same time, potentially new paradigms, such as that of "Cloud Computing" are emerging. This paper summarizes the results of CCRC'08 and discusses the potential impact of future Grid funding on both regional and international application communities. It contrasts Grid and Cloud computing models from both technical and sociological points of view. Finally, it discusses the requirements from production application communities, in terms of stability and continuity in the medium to long term.
Event and Apparent Horizon Finders for 3 + 1 Numerical Relativity.
Thornburg, Jonathan
2007-01-01
Event and apparent horizons are key diagnostics for the presence and properties of black holes. In this article I review numerical algorithms and codes for finding event and apparent horizons in numerically-computed spacetimes, focusing on calculations done using the 3 + 1 ADM formalism. The event horizon of an asymptotically-flat spacetime is the boundary between those events from which a future-pointing null geodesic can reach future null infinity and those events from which no such geodesic exists. The event horizon is a (continuous) null surface in spacetime. The event horizon is defined nonlocally in time : it is a global property of the entire spacetime and must be found in a separate post-processing phase after all (or at least the nonstationary part) of spacetime has been numerically computed. There are three basic algorithms for finding event horizons, based on integrating null geodesics forwards in time, integrating null geodesics backwards in time, and integrating null surfaces backwards in time. The last of these is generally the most efficient and accurate. In contrast to an event horizon, an apparent horizon is defined locally in time in a spacelike slice and depends only on data in that slice, so it can be (and usually is) found during the numerical computation of a spacetime. A marginally outer trapped surface (MOTS) in a slice is a smooth closed 2-surface whose future-pointing outgoing null geodesics have zero expansion Θ. An apparent horizon is then defined as a MOTS not contained in any other MOTS. The MOTS condition is a nonlinear elliptic partial differential equation (PDE) for the surface shape, containing the ADM 3-metric, its spatial derivatives, and the extrinsic curvature as coefficients. Most "apparent horizon" finders actually find MOTSs. There are a large number of apparent horizon finding algorithms, with differing trade-offs between speed, robustness, accuracy, and ease of programming. In axisymmetry, shooting algorithms work well
Joseph-Duran, Bernat; Ocampo-Martinez, Carlos; Cembrano, Gabriela
2015-10-01
An output-feedback control strategy for pollution mitigation in combined sewer networks is presented. The proposed strategy provides means to apply model-based predictive control to large-scale sewer networks, in-spite of the lack of measurements at most of the network sewers. In previous works, the authors presented a hybrid linear control-oriented model for sewer networks together with the formulation of Optimal Control Problems (OCP) and State Estimation Problems (SEP). By iteratively solving these problems, preliminary Receding Horizon Control with Moving Horizon Estimation (RHC/MHE) results, based on flow measurements, were also obtained. In this work, the RHC/MHE algorithm has been extended to take into account both flow and water level measurements and the resulting control loop has been extensively simulated to assess the system performance according different measurement availability scenarios and rain events. All simulations have been carried out using a detailed physically based model of a real case-study network as virtual reality.
Supertranslations and Superrotations at the Black Hole Horizon.
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.
Eocene volcanism and the origin of horizon A
Gibson, T.G.; Towe, K.M.
1971-01-01
A series of closely time-equivalent deposits that correlate with seismic reflector horizon A exists along the coast of eastern North America. These sediments of Late-Early to Early-Middle Eocene age contain an authigenic mineral suite indicative of the alteration of volcanic glass. A volcanic origin for these siliceous deposits onshore is consistent with a volcanic origin for the cherts of horizon A offshore.
Properties of global monopoles with an event horizon
Tamaki, T; Sakai, N
2004-01-01
We investigate the properties of global monopoles with an event horizon. We find that there is an unstable circular orbit even if a particle does not have an angular momentum when the core mass is negative. We also obtain the asymptotic form of solutions when the event horizon is much larger than the core radius of the monopole, and discuss if they could be a model of galactic halos.
Can the 'African household' be presented meaningfully in large ...
African Journals Online (AJOL)
ANBR
population groups (referring to the white, Indian, coloured and black racial categories in South Africa). .... varying, and sometimes conflicting, values in mind. Socioeconomic aspects .... amongst various European and North American countries.
Da Silva, F. M.; Furtado, W. W.
2012-10-01
The main purpose of this study was to analyze the contribution of using hypertext and pedagogic mediation in search of a Meaningful Learning Process in Sciences. We investigate the usage of hypertext in the teaching and learning methods of Astronomy modules. A survey was conducted with students from the 9th grade of Primary School of a public school in the city of Goiânia, Goiás in Brazil. We have analyzed the possibilities that hypermedia can offer in the teaching and learning process, using as reference David Ausubel's Theory of Meaningful Learning. The study was divided into four phases: application of an initial questionnaire on students, development of didactic material (hypertext), six classes held in a computer lab with the use of hypermedia and a final questionnaire applied in the lab after classes. This research indicated that the use of hypertext linked to pedagogical mediation processes is seen as a motivational tool and has potential to foster to Meaningful Learning.
Null infinity and extremal horizons in AdS-CFT
International Nuclear Information System (INIS)
Hickling, Andrew; Wiseman, Toby; Lucietti, James
2015-01-01
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’. (paper)
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.
Job enrichment: creating meaningful career development opportunities for nurses.
Duffield, Christine; Baldwin, Richard; Roche, Michael; Wise, Sarah
2014-09-01
This paper presents an evaluation of a career development policy in South Australia which increased the number of senior staff nurse positions and provided senior registered nurses with time away from clinical duties to undertake agreed projects. We use Kanter's model of structural power and commitment theory to understand the dimensions of this policy. Development strategies for experienced staff who wish to remain at the bedside are needed, especially in smaller health services with limited opportunities for horizontal or vertical mobility. Face-to-face semistructured interviews were conducted with 54 senior staff nurses who participated in the career structure arrangements. The policy enhanced the structure of opportunity in three ways: by increasing the number of senior staff nurse positions, the ladder steps were improved; undertaking strategic projects developed new skills; and the job enrichment approach facilitated time out from the immediate pressures of ward work and challenged nurses in a different way. Through job enrichment, South Australia has found a novel way of providing meaningful career development opportunities for experienced nurses. Methods of job enrichment need to be considered as part of career development policy, especially where movement between clinical facilities is limited and staff wish to remain at the bedside. © 2013 John Wiley & Sons Ltd.
Establishing meaningful cut points for online user ratings.
Hirschfeld, Gerrit; Thielsch, Meinald T
2015-01-01
Subjective perceptions of websites can be reliably measured with questionnaires. But it is unclear how such scores should be interpreted in practice, e.g. is an aesthetics score of 4 points on a seven-point-scale satisfactory? The current paper introduces a receiver-operating characteristic (ROC)-based methodology to establish meaningful cut points for the VisAWI (visual aesthetics of websites inventory) and its short form the VisAWI-S. In two studies we use users' global ratings (UGRs) and website rankings as anchors. A total of 972 participants took part in the studies which yielded similar results. First, one-item UGRs correlate highly with the VisAWI. Second, cut points on the VisAWI reliably differentiate between sites that are perceived as attractive versus unattractive. Third, these cut points are variable, but only within a certain range. Together the research presented here establishes a score of 4.5 on the VisAWI which is a reasonable goal for website designers and highlights the utility of the ROC methodology to derive relevant scores for rating scales.
Redefining meaningful age groups in the context of disease.
Geifman, Nophar; Cohen, Raphael; Rubin, Eitan
2013-12-01
Age is an important factor when considering phenotypic changes in health and disease. Currently, the use of age information in medicine is somewhat simplistic, with ages commonly being grouped into a small number of crude ranges reflecting the major stages of development and aging, such as childhood or adolescence. Here, we investigate the possibility of redefining age groups using the recently developed Age-Phenome Knowledge-base (APK) that holds over 35,000 literature-derived entries describing relationships between age and phenotype. Clustering of APK data suggests 13 new, partially overlapping, age groups. The diseases that define these groups suggest that the proposed divisions are biologically meaningful. We further show that the number of different age ranges that should be considered depends on the type of disease being evaluated. This finding was further strengthened by similar results obtained from clinical blood measurement data. The grouping of diseases that share a similar pattern of disease-related reports directly mirrors, in some cases, medical knowledge of disease-age relationships. In other cases, our results may be used to generate new and reasonable hypotheses regarding links between diseases.
Contributions of meaningful experiences gatherings to artistic education field
Directory of Open Access Journals (Sweden)
Bernardo Bustamante Cardona
2012-06-01
Full Text Available This article shows a theoretical approach to and a description of some contributions of a work of transformation of educational and sociocultural reality carried out by a group of people and institutions, among which are San Buenaventura University, Antioquia Museum, Ediarte Inc. and Antioquia University. Such intervention aims at contributing to the improvement of Artistic Education quality in Antioquia and the nation. In order to understand the significance of these Gatherings, a short historical framework is explained in which global and regional processes of academic activities having an impact on the structure of the Artistic Education field are pointed out. Likewise, some perspectives in the definition of artistic education are tackled and then a definition of Pierre Bourdieu´s concept of fieldis presented. Therefore, Meaningful Experiences Gatherings in Artistic Education (MEGAE are presented and the three first gatherings are described. Finally, it is shown the panorama of the contributions of the gatherings both in the theoretical formulation and relational structure of the field.
Do family physicians electronic health records support meaningful use?
Peterson, Lars E; Blackburn, Brenna; Ivins, Douglas; Mitchell, Jason; Matson, Christine; Phillips, Robert L
2015-03-01
Spurred by government incentives, the use of electronic health records (EHRs) in the United States has increased; however, whether these EHRs have the functionality necessary to meet meaningful use (MU) criteria remains unknown. Our objective was to characterize family physician access to MU functionality when using a MU-certified EHR. Data were obtained from a convenience survey of family physicians accessing their American Board of Family Medicine online portfolio in 2011. A brief survey queried MU functionality. We used descriptive statistics to characterize the responses and bivariate statistics to test associations between MU and patient communication functions by presence of a MU-certified EHR. Out of 3855 respondents, 60% reported having an EHR that supports MU. Physicians with MU-certified EHRs were more likely than physicians without MU-certified EHRs to report patient registry activities (49.7% vs. 32.3%, p-valuevs. 56.4%, p-valuecommunication abilities were low regardless of EHR capabilities. Family physicians with MU-certified EHRs are more likely to report MU functionality; however, a sizeable minority does not report MU functions. Many family physicians with MU-certified EHRs may not successfully meet the successively stringent MU criteria and may face significant upgrade costs to do so. Cross sectional survey. Copyright © 2014 Elsevier Inc. All rights reserved.
Measuring Patient Experiences: Is It Meaningful and Actionable?
Wong, Sabrina T; Johnston, Sharon; Burge, Fred; McGrail, Kim; Hogg, William
2017-10-01
Performance measurement must be meaningful to those being asked to contribute data and to the clinicians who are collecting the information. It must be actionable if performance measurement and reporting is to influence health system transformation. To date, measuring patient experiences in all parts of the healthcare system in Canada lags behind other countries. More attention needs to be paid to capturing patients with complex intersecting health and social problems that result from inequitable distribution of wealth and/or underlying structural inequities related to systemic issues such as racism and discrimination, colonialism and patriarchy. Efforts to better capture the experiences of patients who do not regularly access care and who speak English or French as a second language are also needed. Before investing heavily into collecting patient experience data as part of a performance measurement system the following ought to be considered: (1) ensuring value for and buy-in from clinicians who are being asked to collect the data and/or act on the results; (2) investment in the infrastructure to administer iterative, cost-effective patient/family experience data collection, analysis and reporting (e.g., automated software tools) and (3) incorporating practice support (e.g., facilitation) and health system opportunities to integrate the findings from patient experience surveys into policy and practice. Investment into the infrastructure of measuring, reporting and engaging clinicians in improving practice is needed for patient/caregiver experiences to be acted upon. © 2017 Longwoods Publishing.
Possibilities of creating meaningful encounters in anesthesia nursing
DEFF Research Database (Denmark)
Aagaard, Karin
Anesthesia nursing is performed in a highly technological environment with restricted time for interaction with patients. Patients are in a vulnerable position, which can be characterized by anxiety regarding the anesthetic and surgical procedure. The bedrock of effective nursing care is to facil......Anesthesia nursing is performed in a highly technological environment with restricted time for interaction with patients. Patients are in a vulnerable position, which can be characterized by anxiety regarding the anesthetic and surgical procedure. The bedrock of effective nursing care...... of nursing. In this dissertation, focused ethnography is used to explore the interactions between patients and nurse anesthetists before general anesthesia. Moreover, it will explore the professional identity of nurse anesthetists, in relation to the situation of preparing patients for general anesthesia....... A micro-substantive theory is developed regarding the opportunities for creating meaningful encounters between patients and nurse anesthetists. The theory is based on three dominant motivations for interaction in anesthesia nursing. The context of care is not committed and responsive to the core elements...
Expanding Horizons Teachers and Scientists Collabortaing
Teres, A.
2017-12-01
As a participant in PolarTrec, I joined the crew of NASA's Operation IceBridge in Greenland for the month of April 2017. As an active member of the team I learned the ins and outs of field research, and I learned about the work done by Operation IceBridge. As a result of participating in this project, I grew as a teacher and a scientist. I took my experiences and shared them with my classroom through stories, pictures, videos, and my lesson plans. By seeing the Artic through my experiences the class became enraptured by the subject matter. I was no longer talking about a distant or abstract place instead I was talking about an experience. This enabled my students to take an active part in the discussion and to feel like the cryosphere was part of their life too. Not only did I learn about the science but I leaned about logistics of field research. I reached out to my community and local communications outlets before and after my trip to Greenland to familiarize whomever I could connect with about my experience. I contacted a local news station and they did an interview with me about my trip. I emailed a local newspaper about my trip and was interviewed before I left and after I returned. Due to the newscast, I was contacted by my college sorority and was interviewed for the sorority's national newsletter which is distributed throughout the United States. Each connection helped to spread the word. I'm continuing to spread the word by volunteering to present my experience to schools throughout Broward County in Florida. I've already connected with teachers and schools to set up my presentation in the calendar. Having these types of experiences is critical for teachers to continue their growth within the scientific field and education. Effective teachers are those not constrained by the walls of their classroom. Having the opportunity to work with scientists and do research in the field has expanded my horizons. The people I met I am still in contact with and I am
Is the diagnostic threshold for bulimia nervosa clinically meaningful?
Chapa, Danielle A N; Bohrer, Brittany K; Forbush, Kelsie T
2018-01-01
The DSM-5 differentiates full- and sub-threshold bulimia nervosa (BN) according to average weekly frequencies of binge eating and inappropriate compensatory behaviors. This study was the first to evaluate the modified frequency criterion for BN published in the DSM-5. The purpose of this study was to test whether community-recruited adults (N=125; 83.2% women) with current full-threshold (n=77) or sub-threshold BN (n=48) differed in comorbid psychopathology and eating disorder (ED) illness duration, symptom severity, and clinical impairment. Participants completed the Clinical Impairment Assessment and participated in semi-structured clinical interviews of ED- and non-ED psychopathology. Differences between the sub- and full-threshold BN groups were assessed using MANOVA and Chi-square analyses. ED illness duration, age-of-onset, body mass index (BMI), alcohol and drug misuse, and the presence of current and lifetime mood or anxiety disorders did not differ between participants with sub- and full-threshold BN. Participants with full-threshold BN had higher levels of clinical impairment and weight concern than those with sub-threshold BN. However, minimal clinically important difference analyses suggested that statistically significant differences between participants with sub- and full-threshold BN on clinical impairment and weight concern were not clinically significant. In conclusion, sub-threshold BN did not differ from full-threshold BN in clinically meaningful ways. Future studies are needed to identify an improved frequency criterion for BN that better distinguishes individuals in ways that will more validly inform prognosis and effective treatment planning for BN. Copyright © 2017 Elsevier Ltd. All rights reserved.
Knowledge construction in the classroom: a meaningful pedagogical dialogue
Directory of Open Access Journals (Sweden)
Jesuína Lopes de Almeida Pacca
2015-12-01
Full Text Available Teacher’s performance at their real classroom was analyzed in regard to the applied pedagogical interaction. These teachers were participating in a long range continuous formation course that uses the strategy of analyzing pedagogical planning while it was being elaborated , applied and continuously evaluated by the teacher; the course aimed to the construction of professional competence with an adequate sight of the classroom interaction, within constructivist parameters. The teacher pedagogical planning was the study object: it was discussed continuously by the peers group and the coordinator who intended to point out to the explicit pedagogical content and to the content objectives that were declared for every class plan. The learning objectives and the procedures contained within it were confronted with the real evidence of learning. In these discussions learning concepts that were coherent with constructivism were invoked in addition to science contents and their nature. Dialogue was important in these discussions and stressed as a means for teaching and continuous evaluation. In this dynamical process, the teacher planning was being constantly redrafted, changing the adjustment of that classroom students to the planned knowledge acquisition. This course dynamics, led by the coordinator, intended to be reproduced by participants with their students, at least in part. We noticed surprising results in these teachers professional development besides those that were concretely planned: the transference of the course procedures to the classroom seems to happen in regard to the presence of dialogue but the most meaningful part was individual and particular progress that was included in the development of their classes and led to an improvement of abilities. We concluded that unexpected results can be converted into poles of professional performance growth and performance evolution . These results have led us to give special importance to the
Abbott-Deser-Tekin Charge of Dilaton Black Holes with Squashed Horizons
Institute of Scientific and Technical Information of China (English)
Jun-Jin Peng; Wen-Chang Xiang; Shao-Hong Cai
2016-01-01
We consider the conserved charge of static black holes with squashed horizons in the Einstein-Maxwell-dilaton theory via both the Abbott-Deser-Tekin (ADT) method and its off-shell generalization.We first make use of the original ADT method to compute the mass of the dilaton squashed black holes in terms of three different reference spacetimes,which are the asymptotic geometry,the fiat background and the spacetime of the KaluzaKlein monopole with boundary matched to the original metric,respectively.Each mass satisfies the first law of black hole thermodynamics,although the mass computed on the basis of the boundary matching the KaluzaKlein monopole is different from that of the other two reference spacetimes.Then the mass of the black holes is evaluated through the off-shell generalized ADT method.
Quantization of horizon entropy and the thermodynamics of spacetime
International Nuclear Information System (INIS)
Skakala, Jozef
2014-01-01
This is a review of my work published in the papers of Skakala (JHEP 1201:144, 2012; JHEP 1206:094, 2012) and Chirenti et al. (Phys. Rev. D 86:124008, 2012; Phys. Rev.D 87:044034, 2013). It offers a more detailed discussion of the results than the accounts in those papers, and it links my results to some conclusions recently reached by other authors. It also offers some new arguments supporting the conclusions in the cited articles. The fundamental idea of this work is that the semiclassical quantization of the black hole entropy, as suggested by Bekenstein (Phys. Rev. D 7:2333-2346, 1973), holds (at least) generically for the spacetime horizons. We support this conclusion by two separate arguments: (1) we generalize Bekenstein’s lower bound on the horizon area transition to a much wider class of horizons than only the black-hole horizon, and (2) we obtain the same entropy spectra via the asymptotic quasi-normal frequencies of some particular spherically symmetric multi horizon spacetimes (in the way proposed by Maggiore (Phys. Rev. Lett. 100:141301, 2008)). The main result of this paper supports the conclusions derived by Kothawalla et al. (Phys. Rev. D 78:104018, 2008) and Kwon and Nam (Class. Quant. Grav. 28:035007, 2011), on the basis of different arguments. (author)
How the change in horizon area drives black hole evaporation
International Nuclear Information System (INIS)
Massar, S.; Parentani, R.
2000-01-01
We rephrase the derivation of black hole radiation so as to take into account, at the level of transition amplitudes, the change of the geometry induced by the emission process. This enlarged description reveals that the dynamical variables which govern the emission are the horizon area and its conjugate time variable. Their conjugation is established through the boundary term at the horizon which must be added to the canonical action of general relativity in order to obtain a well defined action principle when the area varies. These coordinates have already been used by Teitelboim and collaborators to compute the partition function of a black hole. We use them to show that the probability to emit a particle is given by e -ΔA/4 , where ΔA is the decrease in horizon area induced by the emission. This expression improves Hawking result which is governed by a temperature (given by the surface gravity) in that the specific heat of the black hole is no longer neglected. The present derivation of quantum black hole radiation is based on the same principles which are used to derive the first law of classical black hole thermodynamics. Moreover, it also applies to quantum processes associated with cosmological or acceleration horizons. These two results indicate that not only black holes but all event horizons possess an entropy which governs processes according to quantum statistical thermodynamics
Beyond the veil: Inner horizon instability and holography
International Nuclear Information System (INIS)
Balasubramanian, Vijay; Levi, Thomas S.
2004-01-01
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
Signature for the absence of an event horizon
International Nuclear Information System (INIS)
Barbieri, James; Chapline, George
2012-01-01
One of the most celebrated predictions of general relativity is that compact astrophysical objects with masses greater than a few solar masses are surrounded by an event horizon where time stands still and communication from the interior to the exterior is cutoff. Despite profound theoretical reasons for doubting whether an event horizon is physically possible, no definitive test as to whether event horizons really exist has yet been proposed. In this Letter we propose an experimental signature for the non-existence of event horizons. In particular we point out that a sharp dip in the spectrum of π 0 decay gamma rays below 70 MeV coming from compact objects with masses exceeding a few solar masses would be definitive evidence that these objects have a physical surface and there is no event horizon. Observation of such gamma rays would also for the first time open an experimental window on physical processes at energies near to the Planck scale. The prospects for seeing the 70 MeV feature in the near future are briefly discussed.
Planning horizon affects prophylactic decision-making and epidemic dynamics.
Nardin, Luis G; Miller, Craig R; Ridenhour, Benjamin J; Krone, Stephen M; Joyce, Paul; Baumgaertner, Bert O
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.
Universality of P−V criticality in horizon thermodynamics
Energy Technology Data Exchange (ETDEWEB)
Hansen, Devin; Kubizňák, David [Perimeter Institute,31 Caroline St. N., Waterloo, Ontario, N2L 2Y5 (Canada); Department of Physics and Astronomy, University of Waterloo,Waterloo, Ontario, N2L 3G1 (Canada); Mann, Robert B. [Department of Physics and Astronomy, University of Waterloo,Waterloo, Ontario, N2L 3G1 (Canada)
2017-01-11
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 δE=TδS−PδV, 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.
Fractal markets: Liquidity and investors on different time horizons
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.
Receding Horizon H∞ Control for Input-Delayed Systems
Directory of Open Access Journals (Sweden)
Han Woong Yoo
2012-01-01
Full Text Available We propose the receding horizon H∞ control (RHHC for input-delayed systems. A new cost function for a finite horizon dynamic game problem is first introduced, which includes two terminal weighting terms parameterized by a positive definite matrix, called a terminal weighing matrix. Secondly, the RHHC is obtained from the solution to the finite dynamic game problem. Thirdly, we propose an LMI condition under which the saddle point value satisfies the nonincreasing monotonicity. Finally, we show the asymptotic stability and H∞ boundedness of the closed-loop system controlled by the proposed RHHC. The proposed RHHC has a guaranteed H∞ performance bound for nonzero external disturbances and the quadratic cost can be improved by adjusting the prediction horizon length for nonzero initial condition and zero disturbance, which is not the case for existing memoryless state-feedback controllers. It is shown through a numerical example that the proposed RHHC is stabilizing and satisfies the infinite horizon H∞ performance bound. Furthermore, the performance in terms of the quadratic cost is shown to be improved by adjusting the prediction horizon length when there exists no external disturbance with nonzero initial condition.
Universality of P−V criticality in horizon thermodynamics
International Nuclear Information System (INIS)
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 δE=TδS−PδV, 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.
Quantum horizon fluctuations of an evaporating black hole
International Nuclear Information System (INIS)
Roura, Albert
2007-01-01
The quantum fluctuations of a black hole spacetime are studied within a low-energy effective field theory approach to quantum gravity. Our approach accounts for both intrinsic metric fluctuations and those induced by matter fields interacting with the gravitational field. Here we will concentrate on spherically symmetric fluctuations of the black hole horizon. Our results suggest that for a sufficiently massive evaporating black hole, fluctuations can accumulate over time and become significant well before reaching Planckian scales. In addition, we provide the sketch of a proof that the symmetrized two-point function of the stress-tensor operator smeared over a null hypersurface is actually divergent and discuss the implications for the analysis of horizon fluctuations. Finally, a natural way to probe quantum metric fluctuations near the horizon is briefly described
Start of new Research and Innovation Programme, Horizon 2020
2013-01-01
The overall EU budget for 2014-2020 was approved on 20 November, with €79 billion allocated for the Horizon 2020 Research and Innovation programme. The first calls and final work programmes in Horizon 2020 will be published on 11 December 2013 and the programme will officially start on 1 January 2014. In preparation for the next major programme, the CERN EU Projects Office has launched a redesigned website to keep you informed and to alert you to opportunities in Horizon 2020: cerneu.web.cern.ch. Organised by Euresearch, the Swiss launch event will take place from 14 to 17 January 2014. This four-day conference will offer the possibility to discover the new European Framework Programme for Research and Innovation. The event is open for registration: www.launch-h2020.ch.
TIME HORIZON AND UNCOVERED INTEREST PARITY IN EMERGING ECONOMIES
Directory of Open Access Journals (Sweden)
Norlida Hanim Mohd Salleh
2011-07-01
Full Text Available The aim of this study is to re-examine the well-known empirical puzzle of uncovered interest parity (UIP for emerging market economies with different prediction time horizons. The empirical results obtained using dynamic panel and time series techniques for monthly data from January 1995 to December 2009 eventually show that the panel data estimates are more powerful than those obtained by applying individual time series estimations and the significant contribution of the exchange rate prediction horizons in determining the status of UIP. This finding reveals that at the longer time horizon, the model has better econometric specification and thus more predictive power for exchange rate movements compared to the shorter time period. The findings can also be a signalling of well-integrated currency markets and a reliable guide to international investors as well as for the orderly conduct of monetary authorities.
Seeking for toroidal event horizons from initially stationary BH configurations
International Nuclear Information System (INIS)
Ponce, Marcelo; Lousto, Carlos; Zlochower, Yosef
2011-01-01
We construct and evolve non-rotating vacuum initial data with a ring singularity, based on a simple extension of the standard Brill-Lindquist multiple BH initial data, and search for event horizons with spatial slices that are toroidal when the ring radius is sufficiently large. While evolutions of the ring singularity are not numerically feasible for large radii, we find some evidence, based on configurations of multiple BHs arranged in a ring, that this configuration leads to singular limit where the horizon width has zero size, possibly indicating the presence of a naked singularity, when the radius of the ring is sufficiently large. This is in agreement with previous studies that have found that there is no apparent horizon surrounding the ring singularity when the ring's radius is larger than about twice its mass.
Towards what Horizon is EU headed by 2020?
Directory of Open Access Journals (Sweden)
Maria Mirona Murea
2013-12-01
Full Text Available Horizon 2020, is a legislative package that succeeds the current FP7, with a proposed budget of EURO 70.9 billion and it has been seen as a response measure to the economic and financial crisis, by creatig the possibilities to invest in future jobs and growth, while addressing EU citizens about their safety, livelihoods and environment. Reliying on a three pillar structure, the funding model focuses on providing the participants similar funding rates according to the undertaken activities, while taking into consideration stakeholders’ preferences for reimbursement. Horizon 2020 is open to any project that is based on competitive initiatives; however, each country’s experience and economic development will influence its’ participation to the “Horizon 2020” funding program.
Near-horizon symmetries of extremal black holes
International Nuclear Information System (INIS)
Kunduri, Hari K; Lucietti, James; Reall, Harvey S
2007-01-01
Recent work has demonstrated an attractor mechanism for extremal rotating black holes subject to the assumption of a near-horizon SO(2, 1) symmetry. We prove the existence of this symmetry for any extremal black hole with the same number of rotational symmetries as known four- and five-dimensional solutions (including black rings). The result is valid for a general two-derivative theory of gravity coupled to Abelian vectors and uncharged scalars, allowing for a non-trivial scalar potential. We prove that it remains valid in the presence of higher-derivative corrections. We show that SO(2, 1)-symmetric near-horizon solutions can be analytically continued to give SU(2)-symmetric black hole solutions. For example, the near-horizon limit of an extremal 5D Myers-Perry black hole is related by analytic continuation to a non-extremal cohomogeneity-1 Myers-Perry solution
Horizons in Matter:. Black Hole Hair Versus Null Big Bang
Bronnikov, K. A.; Zaslavskii, Oleg B.
It is shown that only particular kinds of matter (in terms of the "radial" pressure-to-density ratio w) can coexist with Killing horizons in black hole or cosmological space-times. Thus, for arbitrary (not necessarily spherically symmetric) static black holes, admissible are vacuum matter (w = -1, i.e. the cosmological constant or its generalization with the same value of w) and matter with certain values of w between 0 and -1, in particular a gas of disordered cosmic strings (w = -1/3). If the cosmological evolution starts from a horizon (the so-called null big bang scenarios), this horizon can coexist with vacuum matter and certain kinds of phantom matter with w ≤ -3. It is concluded that normal matter in such scenarios is entirely created from vacuum.
Parametric Covariance Model for Horizon-Based Optical Navigation
Hikes, Jacob; Liounis, Andrew J.; Christian, John A.
2016-01-01
This Note presents an entirely parametric version of the covariance for horizon-based optical navigation measurements. The covariance can be written as a function of only the spacecraft position, two sensor design parameters, the illumination direction, the size of the observed planet, the size of the lit arc to be used, and the total number of observed horizon points. As a result, one may now more clearly understand the sensitivity of horizon-based optical navigation performance as a function of these key design parameters, which is insight that was obscured in previous (and nonparametric) versions of the covariance. Finally, the new parametric covariance is shown to agree with both the nonparametric analytic covariance and results from a Monte Carlo analysis.
Behavioral meaningful opioidergic stimulation activates kappa receptor gene expression
International Nuclear Information System (INIS)
Teodorov, E.; Ferrari, M.F.R.; Fior-Chadi, D.R.; Camarini, R.; Felício, L.F.
2012-01-01
The periaqueductal gray (PAG) has been reported to be a location for opioid regulation of pain and a potential site for behavioral selection in females. Opioid-mediated behavioral and physiological responses differ according to the activity of opioid receptor subtypes. The present study investigated the effects of the peripheral injection of the kappa-opioid receptor agonist U69593 into the dorsal subcutaneous region of animals on maternal behavior and on Oprk1 gene activity in the PAG of female rats. Female Wistar rats weighing 200-250 g at the beginning of the study were randomly divided into 2 groups for maternal behavior and gene expression experiments. On day 5, pups were removed at 7:00 am and placed in another home cage that was distant from their mother. Thirty minutes after removing the pups, the dams were treated with U69593 (0.15 mg/kg, sc) or 0.9% saline (up to 1 mL/kg) and after 30 min were evaluated in the maternal behavior test. Latencies in seconds for pup retrieval, grouping, crouching, and full maternal behavior were scored. The results showed that U69593 administration inhibited maternal behavior (P < 0.05) because a lower percentage of U69593 group dams showed retrieval of first pup, retrieving all pups, grouping, crouching and displaying full maternal behavior compared to the saline group. Opioid gene expression was evaluated using real-time reverse-transcription polymerase chain reaction (RT-PCR). A single injection of U69593 increased Oprk1 PAG expression in both virgin (P < 0.05) and lactating female rats (P < 0.01), with no significant effect on Oprm1 or Oprd1 gene activity. Thus, the expression of kappa-opioid receptors in the PAG may be modulated by single opioid receptor stimulation and behavioral meaningful opioidergic transmission in the adult female might occur simultaneously to specific changes in gene expression of kappa-opioid receptor subtype. This is yet another alert for the complex role of the opioid system in female
Behavioral meaningful opioidergic stimulation activates kappa receptor gene expression
Energy Technology Data Exchange (ETDEWEB)
Teodorov, E. [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, São Paulo, SP (Brazil); Ferrari, M.F.R. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Fior-Chadi, D.R. [Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Camarini, R. [Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP (Brazil); Felício, L.F. [Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP (Brazil)
2012-06-01
The periaqueductal gray (PAG) has been reported to be a location for opioid regulation of pain and a potential site for behavioral selection in females. Opioid-mediated behavioral and physiological responses differ according to the activity of opioid receptor subtypes. The present study investigated the effects of the peripheral injection of the kappa-opioid receptor agonist U69593 into the dorsal subcutaneous region of animals on maternal behavior and on Oprk1 gene activity in the PAG of female rats. Female Wistar rats weighing 200-250 g at the beginning of the study were randomly divided into 2 groups for maternal behavior and gene expression experiments. On day 5, pups were removed at 7:00 am and placed in another home cage that was distant from their mother. Thirty minutes after removing the pups, the dams were treated with U69593 (0.15 mg/kg, sc) or 0.9% saline (up to 1 mL/kg) and after 30 min were evaluated in the maternal behavior test. Latencies in seconds for pup retrieval, grouping, crouching, and full maternal behavior were scored. The results showed that U69593 administration inhibited maternal behavior (P < 0.05) because a lower percentage of U69593 group dams showed retrieval of first pup, retrieving all pups, grouping, crouching and displaying full maternal behavior compared to the saline group. Opioid gene expression was evaluated using real-time reverse-transcription polymerase chain reaction (RT-PCR). A single injection of U69593 increased Oprk1 PAG expression in both virgin (P < 0.05) and lactating female rats (P < 0.01), with no significant effect on Oprm1 or Oprd1 gene activity. Thus, the expression of kappa-opioid receptors in the PAG may be modulated by single opioid receptor stimulation and behavioral meaningful opioidergic transmission in the adult female might occur simultaneously to specific changes in gene expression of kappa-opioid receptor subtype. This is yet another alert for the complex role of the opioid system in female
Behavioral meaningful opioidergic stimulation activates kappa receptor gene expression
Directory of Open Access Journals (Sweden)
E. Teodorov
2012-10-01
Full Text Available The periaqueductal gray (PAG has been reported to be a location for opioid regulation of pain and a potential site for behavioral selection in females. Opioid-mediated behavioral and physiological responses differ according to the activity of opioid receptor subtypes. The present study investigated the effects of the peripheral injection of the kappa-opioid receptor agonist U69593 into the dorsal subcutaneous region of animals on maternal behavior and on Oprk1 gene activity in the PAG of female rats. Female Wistar rats weighing 200-250 g at the beginning of the study were randomly divided into 2 groups for maternal behavior and gene expression experiments. On day 5, pups were removed at 7:00 am and placed in another home cage that was distant from their mother. Thirty minutes after removing the pups, the dams were treated with U69593 (0.15 mg/kg, sc or 0.9% saline (up to 1 mL/kg and after 30 min were evaluated in the maternal behavior test. Latencies in seconds for pup retrieval, grouping, crouching, and full maternal behavior were scored. The results showed that U69593 administration inhibited maternal behavior (P < 0.05 because a lower percentage of kappa group dams showed retrieval of first pup, retrieving all pups, grouping, crouching and displaying full maternal behavior compared to the saline group. Opioid gene expression was evaluated using real-time reverse-transcription polymerase chain reaction (RT-PCR. A single injection of U69593 increased Oprk1 PAG expression in both virgin (P < 0.05 and lactating female rats (P < 0.01, with no significant effect on Oprm1 or Oprd1 gene activity. Thus, the expression of kappa-opioid receptors in the PAG may be modulated by single opioid receptor stimulation and behavioral meaningful opioidergic transmission in the adult female might occur simultaneously to specific changes in gene expression of kappa-opioid receptor subtype. This is yet another alert for the complex role of the opioid system in
Priority Questions and Horizon Scanning for Conservation: A Comparative Study
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
Geometric properties of magnetized black hole event horizons and ergosurfaces
International Nuclear Information System (INIS)
Esteban, E P
2009-01-01
In this paper we focus in the geometric properties of the magnetized Kerr-Newman metric. Three applications are considered. First, the event horizon surface area is calculated and from there we derive the first law of thermodynamics for magnetized black holes. We have obtained analytical expressions for the surface gravity, angular velocity, electric potential, and magnetic moment at the magnetized Kerr-Newman black hole event horizon. An approximate expression for the surface area of the magnetized black hole ergosurface was also obtained. Second, we study the magnetized Kerr-Newman black hole's circumferences. We found that for small values of the angular momentum the event horizon has a prolate spheroid shape. Increasing the value of the angular momentum will change the event horizon shape from a prolate ellipsoid to an oblate spheroid. For small values of the angular momentum and charge the ergosurface shape is an oblate spheroid. Increasing these two parameters will change the ergosurface shape from a oblate spheroid to a prolate spheroid. Third, analytical expressions for the magnetized Kerr-Newman event horizon and ergosurface Gaussian curvatures were obtained although not explicitly shown. Instead a graphical analysis was carried out to visualize regions where Gaussian curvatures take negative or positive values. We found that the Gaussian curvature at the event horizon poles has negative values and do not satisfy Pelavas condition. Therefore, these regions can not be embedded in E 3 . However, the magnetized Kerr-Newman ergosurface can be embedded in E 3 regardless the negative Gaussian curvature values in some regions of the ergosurface.
da Rocha-Neto, J. F.; Morais, B. R.
2018-04-01
In the context of the teleparallel equivalent of general relativity the concept of gravitational pressure and gravitational energy-momentum arisen in a natural way. In the case of a Friedmann-Lemaitre-Robertson-Walker space FLRW we obtain the total energy contained inside the apparent horizon and the radial pressure over the apparent horizon area. We use these definitions to written a thermodynamics relation TAdSA = dEA+PAdVA at the apparent horizon, where EA is the total energy inside the apparent horizon, VA is the areal volume of the apparent horizon, PA is the radial pressure over the apparent horizon area, SA is the entropy which can be assumed as one quarter of the apparent horizon area only for a non stationary apparent horizon. We identify TA as the temperature at the surface of the apparent horizon. We shown that for all expanding accelerated FLRW model of universe the radial pressure is positive.
Astrometry of 2014MU69 for New Horizons encounter
Buie, Marc
2017-08-01
We propose 12 orbits of time to make high-precision astrometric measurments of the New Horizons extendedmission target, (486958) 2014MU69. These observations are in direct support of the navigation of New Horizonsleading up to its encounter in Jan 2019. These visits represent an optimized plan for improved orbit estimates that willcomplete as the target becomes directly observable by New Horizons. This astrometry is a key element leadingup to a close investigation of a Cold-Classical Kuiper Belt Object, one of the most primitive members of our solarsystem.
Horizon strings and interior states of a black hole
Directory of Open Access Journals (Sweden)
K.P. Yogendran
2015-11-01
Full Text Available We provide an explicit construction of classical strings that have endpoints on the horizons of the 2D Lorentzian black hole. We argue that this is a dual description of geodesics that are localized around the horizon which are the Lorentzian counterparts of the winding strings of the Euclidean black hole (the cigar geometry. Identifying these with the states of the black hole, we can expect that issues of black hole information loss can be posed sharply in terms of a fully quantizable string theory.
The role of event horizons in quantum gravity
International Nuclear Information System (INIS)
Schiffer, M.
1990-01-01
We extend Bekenstein's result for the minimum variation of the black hole event horizon due to the absorption of an extended (classical) particle to the deSitter Universe. These classical equations are the bulk for the argument based on correspondence principle: for large energies the classical and quantum results are in correspondence with each other. The outcome of this reasoning could not be more fruitful: it leads to the quantization of the event horizon area (either B.H. or cosmological) in units of Planck's length square. Consequence are discussed. (author)
Quasilocal energy, Komar charge and horizon for regular black holes
International Nuclear Information System (INIS)
Balart, Leonardo
2010-01-01
We study the Brown-York quasilocal energy for regular black holes. We also express the identity that relates the difference of the Brown-York quasilocal energy and the Komar charge at the horizon to the total energy of the spacetime for static and spherically symmetric black hole solutions in a convenient way which permits us to understand why this identity is not satisfied when we consider nonlinear electrodynamics. However, we give a relation between quantities evaluated at the horizon and at infinity when nonlinear electrodynamics is considered. Similar relations are obtained for more general static and spherically symmetric black hole solutions which include solutions of dilaton gravity theories.
E(7) symmetric area of the black hole horizon
International Nuclear Information System (INIS)
Kallosh, R.; Kol, B.
1996-01-01
Extreme black holes with 1/8 of unbroken N=8 supersymmetry are characterized by the nonvanishing area of the horizon. The central charge matrix has four generic eigenvalues. The area is proportional to the square root of the invariant quartic form of E 7(7) . It vanishes in all cases when 1/4 or 1/2 of supersymmetry is unbroken. The supergravity nonrenormalization theorem for the area of the horizon in the N=8 case protects the unique U-duality invariant. copyright 1996 The American Physical Society
Earth, Meet Pluto: The New Horizons Education and Communications Partnership
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
Robust Consumption-Investment Problem on Infinite Horizon
Energy Technology Data Exchange (ETDEWEB)
Zawisza, Dariusz, E-mail: dariusz.zawisza@im.uj.edu.pl [Jagiellonian University in Krakow, Institute of Mathematics, Faculty of Mathematics and Computer Science (Poland)
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.
Perera, S.; Studenski, S.; Newman, A.; Simonsick, E.; Harris, T.; Schwartz, A.; Visser, M.
2014-01-01
Background: Meaningful change criteria help determine if function has improved or declined, but their magnitudes may vary across clinically relevant subgroups. We estimate meaningful decline in four common measures of physical performance in subgroups of older adults based on initial performance,
Galloway, Kelli R.; Bretz, Stacey Lowery
2015-01-01
Research on learning in the undergraduate chemistry laboratory necessitates an understanding of students' perspectives of learning. Novak's Theory of Meaningful Learning states that the cognitive (thinking), affective (feeling), and psychomotor (doing) domains must be integrated for meaningful learning to occur. The psychomotor domain is the…
Meaningful Experiences in Physical Education and Youth Sport: A Review of the Literature
Beni, Stephanie; Fletcher, Tim; Ní Chróinín, Déirdre
2017-01-01
The purpose of this research is to review the literature about young people's meaningful experiences in physical education and youth sport. We reviewed 50 empirical peer-reviewed articles published in English since 1987. Five themes were identified as central influences to young people's meaningful experiences in physical education and sport:…
Directory of Open Access Journals (Sweden)
H Jenaabadi
2014-07-01
Conclusion: Given a significant positive correlation between appeal to God and meaningful life, it is suggested including spirituality therapy sessions and teaching religious coping methods to reduce stress and thus make meaningful life in these parents by welfare, education of exceptional children, and radio and television organizations.
Eakman, Aaron M.; Carlson, Mike E.; Clark, Florence A.
2010-01-01
The Meaningful Activity Participation Assessment (MAPA), a recently developed 28-item tool designed to measure the meaningfulness of activity, was tested in a sample of 154 older adults. The MAPA evidenced a sufficient level of internal consistency and test-retest reliability and correlated as theoretically predicted with the Life Satisfaction…
A Continuum of Learning: From Rote Memorization to Meaningful Learning in Organic Chemistry
Grove, Nathaniel P.; Bretz, Stacey Lowery
2012-01-01
The Assimilation Theory of Ausubel and Novak has typically been used in the research literature to describe two extremes to learning chemistry: meaningful learning "versus" rote memorization. It is unlikely, however, that such discrete categories of learning exist. Rote and meaningful learning, rather, are endpoints along a continuum of…
Meaningful Watershed Experiences for Middle and High School Students
Landry, Melinda; Smith, Cynthia; Greene, Joy
2014-05-01
Prince William County Public Schools and George Mason University in Virginia, USA, partnered to provide Meaningful Watershed Educational Experiences (MWEEs) for over 25,000 middle and high school students (11-18 year olds) across 34 schools. This school district, situated in a rapidly growing region 55 km southwest of Washington DC, has over 82,000 K-12 students. As native forest cover has been replaced with farming and urbanization, water quality has significantly degraded in the 166,534 km2 Chesapeake Bay watershed. This project was designed to increase student awareness of their impact on the land and waters of the largest estuary in the United States. MWEE is a long-term comprehensive project that incorporates a classroom preparation phase, a hands-on outdoor field investigation, and a reflection and data-sharing component. Training and technical assistance enhances the capacity of teachers of 6th grade, high school Earth Science and Environmental Science to deliver MWEEs which includes schoolyard stewardship, inquiry driven field study, use of hand-held technology and computer based mapping and analysis, project sharing and outreach. George Mason University researchers worked closely with K-12 science educators to create a comprehensive watershed-focused curriculum. Graduate and undergraduate students with strong interests in environmental science and education were trained to deliver the field investigation component of the MWEE. Representative teachers from each school were provided 3 days of professional development and were responsible for the training of their school's science education team. A comprehensive curriculum provided teachers with activities and tools designed to enhance students' mastery of state science objectives. Watershed concepts were used as the unifying theme to support student understanding of curriculum and STEM objectives including: scientific investigation, data collection and communication, chemistry, energy, erosion, human
Knowledge horizons: the present and the promise of knowledge management
National Research Council Canada - National Science Library
Chauvel, Daniele; Despres, Charles
2000-01-01
... what has been written, Butterworth- Heinemann prints its books on acid-free paper whenever possible. Butterworth- Heinemann supports the efforts of American Forests and the Global ReLeaf program in its campaign for the betterment of trees, forests, and our environment. Library of Congress Cataloging-in-Publication Data Knowledge horizons : the present ...
Selective depletion of organic matter in mottled podzol horizons
Buurman, P.; Schellekens, J.; Fritze, H.; Nierop, K.G.J.
2007-01-01
Abstract: Some well-drained podzols on quartz sands in the Netherlands and neighbouring Belgium and Germany show mottling in all horizons due to selective removal of organic matter. Phospholipid analysis and morphology of the mottles suggests that this removal is due to activity of fungi.
Selective depletion of organic matter in mottled podzol horizons
Buurman, P.; Schellekens, J.F.P.; Fritze, H.; Nierop, K.G.J.
2007-01-01
Some well-drained podzols on quartz sands in the Netherlands and neighbouring Belgium and Germany show mottling in all horizons due to selective removal of organic matter. Phospholipid analysis and morphology of the mottles suggests that this removal is due to a combination of bacteria, fungi, and
Computing security strategies in finite horizon repeated Bayesian games
Lichun Li; Langbort, Cedric; Shamma, Jeff S.
2017-01-01
in the worst case. First, a security strategy that directly depends on both players' history actions is derived by refining the sequence form. Noticing that history action space grows exponentially with respect to the time horizon, this paper further presents a
Horizon structure of rotating Bardeen black hole and particle acceleration
International Nuclear Information System (INIS)
Ghosh, Sushant G.; Amir, Muhammed
2015-01-01
We investigate the horizon structure and ergosphere in a rotating Bardeen regular black hole, which has an additional parameter (g) due to the magnetic charge, apart from the mass (M) and the rotation parameter (a). Interestingly, for each value of the parameter g, there exists a critical rotation parameter (a = a E ), which corresponds to an extremal black hole with degenerate horizons, while for a < a E it describes a non-extremal black hole with two horizons, and no black hole for a > a E . We find that the extremal value a E is also influenced by the parameter g, and so is the ergosphere. While the value of a E remarkably decreases when compared with the Kerr black hole, the ergosphere becomes thicker with the increase in g.We also study the collision of two equal mass particles near the horizon of this black hole, and explicitly show the effect of the parameter g. The center-of-mass energy (E CM ) not only depend on the rotation parameter a, but also on the parameter g. It is demonstrated that the E CM could be arbitrarily high in the extremal cases when one of the colliding particles has a critical angular momentum, thereby suggesting that the rotating Bardeen regular black hole can act as a particle accelerator. (orig.)
Gravitational black hole hair from event horizon supertranslations
Energy Technology Data Exchange (ETDEWEB)
Averin, Artem [Arnold-Sommerfeld-Center for Theoretical Physics,Ludwig-Maximilians-Universität, 80333 München (Germany); Max-Planck-Institut für Physik, Werner-Heisenberg-Institut,80805 München (Germany); Dvali, Gia [Arnold-Sommerfeld-Center for Theoretical Physics,Ludwig-Maximilians-Universität, 80333 München (Germany); Max-Planck-Institut für Physik, Werner-Heisenberg-Institut,80805 München (Germany); Center for Cosmology and Particle Physics, Department of Physics, New York University,4 Washington Place, New York, NY 10003 (United States); Gomez, Cesar [Instituto de Física Teórica UAM-CSIC, C-XVI, Universidad Autónoma de Madrid,Cantoblanco, 28049 Madrid (Spain); Lüst, Dieter [Arnold-Sommerfeld-Center for Theoretical Physics,Ludwig-Maximilians-Universität, 80333 München (Germany); Max-Planck-Institut für Physik, Werner-Heisenberg-Institut,80805 München (Germany)
2016-06-16
We discuss BMS supertranslations both at null-infinity BMS{sup −} and on the horizon BMS{sup 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 A≡BMS{sup H}/BMS{sup −} 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 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.
advancing the frontiers of pharmacy profession to new horizons
African Journals Online (AJOL)
Prof.Thoithi
The practice of pharmacy has been changing over the years prompting pharmacists to explore new horizons. In many medical schools teaching of clinical pharmacology has been upgraded from the previous materia medica thus eroding the comparative advantage pharmacists previously enjoyed over their medical ...
Introductory essay: new horizons in cross cultural management
Zhu, Y.; Ulijn, J.M.
2005-01-01
In this special issue, we present a research forum on current issues in cross cultural management in New Zealand, Australia and the Asian-Pacific Region. Our theme is new horizons in cross cultural management, which is reflected in both topic and approach. Our topics are related to the Asia Pacific
Horizons in 2+1-dimensional collapse of particles
Indian Academy of Sciences (India)
A simple, geometrical construction is given for three-dimensional spacetimes with negative cosmological constant that contain two particles colliding head-on. Depending on parameters like particle masses and distance, the combined geometry will be that of a particle, or of a black hole. In the black hole case the horizon is ...
Application of capital replacement models with finite planning horizons
Scarf, P.A.; Christer, A.H.
1997-01-01
Capital replacement models with finite planning horizons can be used to model replacement policies in complex operational contexts. They may also be used to investigate the cost consequences of technological change. This paper reviews the application of these models in various such contexts. We also
Investment horizons : A time-dependent measure of asset performance
Ingve Simonsen; Anders Johansen; Mogens H. Jensen
2005-01-01
We review a resent {\\em time-dependent} performance measure for economical time series -- the (optimal) investment horizon approach. For stock indices, the approach shows a pronounced gain-loss asymmetry that is {\\em not} observed for the individual stocks that comprise the index. This difference may hint towards an synchronize of the draw downs of the stocks.
Promise Okekwe: Rising Star on the Nigerian Literary Horizon ...
African Journals Online (AJOL)
... a young and upcoming talent on the Nigeria literary horizon. Okekwe was first published in 1992. A resilient and dynamic writer, she has continued to produce texts at a pace akin to Buchi Emecheta's. Her works reveal a remarkable understanding of the human mind. She thus aims at a reconstruction of the wider society.
Gravitational black hole hair from event horizon supertranslations
International Nuclear Information System (INIS)
Averin, Artem; Dvali, Gia; Gomez, Cesar; Lüst, Dieter
2016-01-01
We discuss BMS supertranslations both at null-infinity BMS"− and on the horizon BMS"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 A≡BMS"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 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.
Pareto optimality in infinite horizon linear quadratic differential games
Reddy, P.V.; Engwerda, J.C.
2013-01-01
In this article we derive conditions for the existence of Pareto optimal solutions for linear quadratic infinite horizon cooperative differential games. First, we present a necessary and sufficient characterization for Pareto optimality which translates to solving a set of constrained optimal
Receding-horizon adaptive contyrol of aero-optical wavefronts
Tesch, J.; Gibson, S.; Verhaegen, M.
2013-01-01
A new method for adaptive prediction and correction of wavefront errors in adaptive optics (AO) is introduced. The new method is based on receding-horizon control design and an adaptive lattice filter. Experimental results presented illustrate the capability of the new adaptive controller to predict
Decentralized Receding Horizon Control and Coordination of Autonomous Vehicle Formations
Keviczky, T.; Borelli, F.; Fregene, K.; Godbole, D.; Bals, G.J.
2008-01-01
This paper describes the application of a novel methodology for high-level control and coordination of autonomous vehicle teams and its demonstration on high-fidelity models of the organic air vehicle developed at Honeywell Laboratories. The scheme employs decentralized receding horizon controllers
Stochastic Dynamics of Clay Translocation and Formation of Argillic Horizons
Calabrese, S.; Richter, D. D., Jr.; Porporato, A. M.
2017-12-01
The formation of argillic horizons in vertical soil profiles is mainly attributed to lessivage, namely the transport of clay from an upper E horizon to a deeper illuviated horizon. Because of the long timescales involved in this phenomenon, quantitative modeling is useful to explore the role of clay lessivage on soil formation and sub-surface clay accumulation. The limitations of detailed models of colloidal transport to short timescales make it necessary to resort to simple models. Here, we present a parsimonious model of clay transport in which lessivage is interpreted stochastically. Clay particles approach the soil surface at a speed equal to the erosion rate and are intermittently transported to deeper soil layers when percolation events occur or removed by erosion. Along with the evolution of clay particles trajectories, the model predicts the vertical clay profile, the depth of the B horizon, and the mean time to erosion. Dimensional analysis reveals the two dimensionless parameters governing the dynamics, leading to a new classification of soil types based on erosion rates and intensity of lessivage.
Canonical Ensemble Model for Black Hole Horizon of Schwarzschild ...
Indian Academy of Sciences (India)
Abstract. In this paper, we use the canonical ensemble model to discuss the radiation of a Schwarzschild–de Sitter black hole on the black hole horizon. Using this model, we calculate the probability distribution from function of the emission shell. And the statistical meaning which compare with the distribution function is ...
The Impact of Horizon 2020 on Innovation in Europe
Veugelers, R.; Cincera, M.; Frietsch, R.; Rammer, C.; Schubert, T.; Pelle, A.; Renda, A.; Montalvo Corral, C.; Leijten, J.
2015-01-01
The EU’s stagnation on many innovation indicators led to a number of efforts to spur a turnaround. One of most visible projects has been the Horizon 2020 strategy, which devotes unprecedented levels of funding to the promotion of R&D and innovation. But does this strategy address the right issues to
CFT/gravity correspondence on the isolated horizon
Energy Technology Data Exchange (ETDEWEB)
Ghosh, Amit, E-mail: amit.ghosh@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, 700064 Kolkata (India); Pranzetti, Daniele, E-mail: daniele.pranzetti@gravity.fau.de [Institute for Quantum Gravity, University of Erlangen-Nürnberg (FAU), Staudtstrasse 7/B2, 91058 Erlangen (Germany)
2014-12-15
A quantum isolated horizon can be modelled by an SU(2) Chern–Simons theory on a punctured 2-sphere. We show how a local 2-dimensional conformal symmetry arises at each puncture inducing an infinite set of new observables localised at the horizon which satisfy a Kac–Moody algebra. By means of the isolated horizon boundary conditions, we represent the gravitational flux degrees of freedom in terms of the zero modes of the Kac–Moody algebra defined on the boundary of a punctured disk. In this way, our construction encodes a precise notion of CFT/gravity correspondence. The higher modes in the algebra represent new nongeometric charges which can be represented in terms of free matter field degrees of freedom. When computing the CFT partition function of the system, these new states induce an extra degeneracy factor, representing the density of horizon states at a given energy level, which reproduces the Bekenstein's holographic bound for an imaginary Immirzi parameter. This allows us to recover the Bekenstein–Hawking entropy formula without the large quantum gravity corrections associated with the number of punctures.
Attractor horizons in six-dimensional type IIB supergravity
Energy Technology Data Exchange (ETDEWEB)
Astefanesei, Dumitru, E-mail: dumitru.astefanesei@ucv.cl [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Casilla 4059, Valparaiso (Chile); Miskovic, Olivera, E-mail: olivera.miskovic@ucv.cl [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Casilla 4059, Valparaiso (Chile); Olea, Rodrigo, E-mail: rodrigo.olea@unab.cl [Universidad Andres Bello, Departamento de Ciencias Fisicas, Republica 220, Santiago (Chile)
2012-08-14
We consider near horizon geometries of extremal black holes in six-dimensional type IIB supergravity. In particular, we use the entropy function formalism to compute the charges and thermodynamic entropy of these solutions. We also comment on the role of attractor mechanism in understanding the entropy of the Hopf T-dual solutions in type IIA supergravity.
Short-horizon regulation for long-term investors
Shi, Z.; Werker, B.J.M.
2012-01-01
We study the effects of imposing repeated short-horizon regulatory constraints on long-term investors. We show that Value-at-Risk and Expected Shortfall constraints, when imposed dynamically, lead to similar optimal portfolios and wealth distributions. We also show that, in utility terms, the costs
Visions for Horizon 2020 from Copenhagen Research Forum
DEFF Research Database (Denmark)
Brenneche, Nicolaj Tofte; Højgaard, Liselotte
2012-01-01
In January 2012, the Copenhagen Research Forum (CRF) gathered 80 European scientists to discuss the societal chal-lenges to be addressed by Horizon 2020, the next framework programme for European research and innovation, and consider how research could contribute the best solutions. This EFP brie...
Horizon geometry for Kerr black holes with synchronized hair
Delgado, Jorge F. M.; Herdeiro, Carlos A. R.; Radu, Eugen
2018-06-01
We study the horizon geometry of Kerr black holes (BHs) with scalar synchronized hair [1], a family of solutions of the Einstein-Klein-Gordon system that continuously connects to vacuum Kerr BHs. We identify the region in parameter space wherein a global isometric embedding in Euclidean 3-space, E3, is possible for the horizon geometry of the hairy BHs. For the Kerr case, such embedding is possible iff the horizon dimensionless spin jH (which equals the total dimensionless spin, j ), the sphericity s and the horizon linear velocity vH are smaller than critical values, j(S ),s(S ),vH(S ), respectively. For the hairy BHs, we find that jH
Rolling-horizon replenishment : Policies and performance analysis
Lian, Z.; Liu, L.; Zhu, Stuart X.
We consider a rolling-horizon (RH) replenishment modeling framework under which a buyer can update demand information and inventory status, modify order quantities committed previously, place an advanced order for a new period at the end of the RH, and move along in time seamlessly. We show that the
Shuster, W.; Schifman, L. A.; Herrmann, D.
2017-12-01
Green infrastructure represents a broad set of site- to landscape-scale practices that can be flexibly implemented to increase sewershed retention capacity, and can thereby improve on the management of water quantity and quality. Although much green infrastructure presents as formal engineered designs, urbanized landscapes with highly-interspersed pervious surfaces (e.g., right-of-way, parks, lawns, vacant land) may offer ecosystem services as passive, infiltrative green infrastructure. Yet, infiltration and drainage processes are regulated by soil surface conditions, and then the layering of subsoil horizons, respectively. Drawing on a unique urban soil taxonomic and hydrologic dataset collected in 12 cities (each city representing a major soil order), we determined how urbanization processes altered the sequence of soil horizons (compared to pre-urbanized reference soil pedons) and modeled the hydrologic implications of these shifts in layering with an unsaturated zone code (HYDRUS2D). We found that the different layering sequences in urbanized soils render different types and extents of supporting (plant-available soil water), provisioning (productive vegetation), and regulating (runoff mitigation) ecosystem services.
Cemented Horizons and Hardpans in the Coastal Tablelands of Northeastern Brazil
Directory of Open Access Journals (Sweden)
João Bosco Vasconcellos Gomes
Full Text Available ABSTRACT Horizons with varying degrees of cementation are a common feature of the soils from the coastal tablelands of Northeastern Brazil. In most cases, these horizons are represented by the following subsurface horizons: fragipan, duripan, ortstein, and placic. The aims of this study were to analyze differences regarding the development and the degree of expression of cementation in soils from the coastal tablelands of Northeastern Brazil: Planossolo Háplico (p-SX, Espodossolo Humilúvico (p-EK, Espodossolo Ferrihumilúvico (p-ESK, and Argissolo Acinzentado (p-PAC pedons. The pedons studied displayed features related to drainage impediments. The cemented horizons from p-SX and p-EK had the same designation (Btgm, displaying a duric character that coincided with gleization features and are under podzolized horizons. In the p-ESK, the podzolization process is of such magnitude that it leads to the cementation of its own spodic horizons, which were both of the ortstein type (Bhsx and Bsm. In the p-PAC cementation is observed in two placic horizons and in the Btx/Bt horizon, as well as in the upper parts of the Bt/Btx horizon. Analysis of the micrographies from the cemented horizons showed predominance of a low porosity matrix. Such porosity is relatively greater in the horizons of “x” subscript than in the horizons with duric character. The Fe segregation lines were notable in the cemented horizons from p-EK and p-PAC, which corroborates the presence of placic horizons in such pedons. The preponderance of kaolinite in the clay fraction was widely verified in all the cemented horizons analyzed. Water immersion tests were the criteria adopted to define the duric character of the Btgm horizons from p-SX and p-EK, and in the Bsm horizon from the p-ESK. These tests were also used to confirm field morphology. In most cases, the maximum values of Fe, Al, and Si, determined by different extractions, occurred in positions overlaying the cemented
Hematological indices of injury to lightly oiled birds from the Deepwater Horizon oil spill
Fallon, Jesse A.; Smith, Eric P.; Schoch, Nina; Paruk, James D.; Adams, Evan A.; Evers, David C.; Jodice, Patrick G. R.; Perkins, Christopher; Schulte, Shiloh A.; Hopkins, William A.
2018-01-01
Avian mortality events are common following large‐scale oil spills. However, the sublethal effects of oil on birds exposed to light external oiling are not clearly understood. We found that American oystercatchers (area of potential impact n = 42, reference n = 21), black skimmers (area of potential impact n = 121, reference n = 88), brown pelicans (area of potential impact n = 91, reference n = 48), and great egrets (area of potential impact n = 57, reference n = 47) captured between 20 June 2010 and 23 February 2011 following the Deepwater Horizon oil spill experienced oxidative injury to erythrocytes, had decreased volume of circulating erythrocytes, and showed evidence of a regenerative hematological response in the form of increased reticulocytes compared with reference populations. Erythrocytic inclusions consistent with Heinz bodies were present almost exclusively in birds from sites impacted with oil, a finding pathognomonic for oxidative injury to erythrocytes. Average packed cell volumes were 4 to 19% lower and average reticulocyte counts were 27 to 40% higher in birds with visible external oil than birds from reference sites. These findings provide evidence that small amounts of external oil exposure are associated with hemolytic anemia. Furthermore, we found that some birds captured from the area impacted by the spill but with no visible oiling also had erythrocytic inclusion bodies, increased reticulocytes, and reduced packed cell volumes when compared with birds from reference sites. Thus, birds suffered hematologic injury despite no visible oil at the time of capture. Together, these findings suggest that adverse effects of oil spills on birds may be more widespread than estimates based on avian mortality or severe visible oiling.
Implication of Negative Temperature in the Inner Horizon of Reissner-Nordström Black Hole
Directory of Open Access Journals (Sweden)
Yuant Tiandho
2017-12-01
Full Text Available This paper reconsiders the properties of Hawking radiation in the inner horizon of a Reissner-Nordström black hole. Through the correlation between temperature and surface gravity, it is concluded that the temperature of the inner horizon is always negative and that of the outer horizon is always positive. Since negative temperature is hotter than any positive temperature, it is predicted that particle radiation from the inner horizon will move toward the outer horizon. However, unlike temperature, entropy in both horizons remains positive. Following the definition of negative temperature in the inner horizon, it is assured that the entropy of a black hole within a closed system can never decrease. By analyzing the conditions of an extremal black hole, the third law of black hole thermodynamics can be extended to multi-horizon black holes.
Black hole and cosmos with multiple horizons and multiple singularities in vector-tensor theories
Gao, Changjun; Lu, Youjun; Yu, Shuang; Shen, You-Gen
2018-05-01
A stationary and spherically symmetric black hole (e.g., Reissner-Nordström black hole or Kerr-Newman black hole) has, at most, one singularity and two horizons. One horizon is the outer event horizon and the other is the inner Cauchy horizon. Can we construct static and spherically symmetric black hole solutions with N horizons and M singularities? The de Sitter cosmos has only one apparent horizon. Can we construct cosmos solutions with N horizons? In this article, we present the static and spherically symmetric black hole and cosmos solutions with N horizons and M singularities in the vector-tensor theories. Following these motivations, we also construct the black hole solutions with a firewall. The deviation of these black hole solutions from the usual ones can be potentially tested by future measurements of gravitational waves or the black hole continuum spectrum.
Approximate Receding Horizon Approach for Markov Decision Processes: Average Award Case
National Research Council Canada - National Science Library
Chang, Hyeong S; Marcus, Steven I
2002-01-01
...) with countable state space, finite action space, and bounded rewards that uses an approximate solution of a fixed finite-horizon sub-MDP of a given infinite-horizon MDP to create a stationary policy...
Horizons of description: Black holes and complementarity
Bokulich, Peter Joshua Martin
Niels Bohr famously argued that a consistent understanding of quantum mechanics requires a new epistemic framework, which he named complementarity . This position asserts that even in the context of quantum theory, classical concepts must be used to understand and communicate measurement results. The apparent conflict between certain classical descriptions is avoided by recognizing that their application now crucially depends on the measurement context. Recently it has been argued that a new form of complementarity can provide a solution to the so-called information loss paradox. Stephen Hawking argues that the evolution of black holes cannot be described by standard unitary quantum evolution, because such evolution always preserves information, while the evaporation of a black hole will imply that any information that fell into it is irrevocably lost---hence a "paradox." Some researchers in quantum gravity have argued that this paradox can be resolved if one interprets certain seemingly incompatible descriptions of events around black holes as instead being complementary. In this dissertation I assess the extent to which this black hole complementarity can be undergirded by Bohr's account of the limitations of classical concepts. I begin by offering an interpretation of Bohr's complementarity and the role that it plays in his philosophy of quantum theory. After clarifying the nature of classical concepts, I offer an account of the limitations these concepts face, and argue that Bohr's appeal to disturbance is best understood as referring to these conceptual limits. Following preparatory chapters on issues in quantum field theory and black hole mechanics, I offer an analysis of the information loss paradox and various responses to it. I consider the three most prominent accounts of black hole complementarity and argue that they fail to offer sufficient justification for the proposed incompatibility between descriptions. The lesson that emerges from this
The journey of primary care practices to meaningful use: a Colorado Beacon Consortium study.
Fernald, Douglas H; Wearner, Robyn; Dickinson, W Perry
2013-01-01
The Health Information Technology for Economic and Clinical Health Act of 2009 provides for incentive payments through Medicare and Medicaid for clinicians who implement electronic health records (EHRs) and use this technology meaningfully to improve patient care. There are few comprehensive descriptions of how primary care practices achieve the meaningful use of clinical data, including the formal stage 1 meaningful use requirements. Evaluation of the Colorado Beacon Consortium project included iterative qualitative analysis of practice narratives, provider and staff interviews, and separate focus groups with quality improvement (QI) advisors and staff from the regional health information exchange (HIE). Most practices described significant realignment of practice priorities and aims, which often required substantial education and training of physicians and staff. Re-engineering office processes, data collection protocols, EHRs, staff roles, and practice culture comprised the primary effort and commitment to attest to stage 1 meaningful use and subsequent meaningful use of clinical data. While realizing important benefits, practices bore a significant burden in learning the true capabilities of their EHRs with little effective support from vendors. Attestation was an important initial milestone in the process, but practices faced substantial ongoing work to use their data meaningfully for patient care and QI. Key resources were instrumental to these practices: local technical EHR expertise; collaborative learning mechanisms; and regular contact and support from QI advisors. Meeting the stage 1 requirements for incentives under Medicare and Medicaid meaningful use criteria is the first waypoint in a longer journey by primary care practices to the meaningful use of electronic data to continuously improve the care and health of their patients. The intensive re-engineering effort for stage 1 yielded practice changes consistent with larger practice aims and goals
Enhancing Collaborative and Meaningful Language Learning Through Concept Mapping
Marriott, Rita De Cássia Veiga; Torres, Patrícia Lupion
This chapter aims to investigate new ways of foreign-language teaching/learning via a study of how concept mapping can help develop a student's reading, writing and oral skills as part of a blended methodology for language teaching known as LAPLI (Laboratorio de Aprendizagem de LInguas: The Language Learning Lab). LAPLI is a student-centred and collaborative methodology which encourages students to challenge their limitations and expand their current knowledge whilst developing their linguistic and interpersonal skills. We explore the theories that underpin LAPLI and detail the 12 activities comprising its programme with specify reference to the use of "concept mapping". An innovative table enabling a formative and summative assessment of the concept maps is formulated. Also presented are some of the qualitative and quantitative results achieved when this methodology was first implemented with a group of pre-service students studying for a degree in English and Portuguese languages at the Catholic University of Parana (PUCPR) in Brazil. The contribution of concept mapping and LAPLI to an under standing of language learning along with a consideration of the difficulties encountered in its implementation with student groups is discussed and suggestions made for future research.
The Event Horizon of The Schwarzschild Black Hole in Noncommutative Spaces
Nasseri, Forough
2005-01-01
The event horizon of Schwarzschild black hole is obtained in noncommutative spaces up to the second order of perturbative calculations. Because this type of black hole is non-rotating, to the first order there is no any effect on the event horizon due to the noncommutativity of space. A lower limit for the noncommutativity parameter is also obtained. As a result, the event horizon in noncommutative spaces is less than the event horizon in commutative spaces.
On crossing the Cauchy horizon of a Reissner-Nordstroem black-hole
International Nuclear Information System (INIS)
Chandrasekhar, S.; Hartle, J.B.
1982-01-01
The behaviour, on the Cauchy horizon, of a flux of gravitational and/or electromagnetic radiation crossing the event horizon of a Reissner-Nordstroem black-hole is investigated as a problem in the theory of one-dimensional potential-scattering. It is shown that the flux of radiation received by an observer crossing the Cauchy horizon, along a radial time-like geodesic, diverges for all physically perturbations crossing the event horizon, even including those with compact support. (author)
Is thermodynamics of the universe bounded by event horizon a Bekenstein system?
International Nuclear Information System (INIS)
Chakraborty, Subenoy
2012-01-01
In this brief communication, we have studied the validity of the first law of thermodynamics for the universe bounded by event horizon with two examples. The key point is the appropriate choice of the temperature on the event horizon. Finally, we have concluded that universe bounded by the event horizon may be a Bekenstein system and Einstein's equations and the first law of thermodynamics on the event horizons are equivalent.
Is thermodynamics of the universe bounded by event horizon a Bekenstein system?
Chakraborty, Subenoy
2012-01-01
In this brief communication, we have studied the validity of the first law of thermodynamics for the universe bounded by event horizon with two examples. The key point is the appropriate choice of the temperature on the event horizon. Finally, we have concluded that universe bounded by the event horizon may be a Bekenstein system and the Einstein's equations and the first law of thermodynamics on the event horizons are equivalent.
International Nuclear Information System (INIS)
Zhang Jingyi; Zhao Zheng
2011-01-01
In this paper, with the Parikh-Wilczek tunnelling framework the positions of the event horizon of the Vaidya black hole and the Vaidya-Bonner black hole are calculated, respectively. We find that the event horizon and the apparent horizon of these two black holes correspond, respectively, to the two turning points of the Hawking radiation tunnelling barrier. That is, the quantum ergosphere coincides with the tunnelling barrier. Our calculation also implies that the Hawking radiation comes from the apparent horizon.
Values-led Participatory Design as a pursuit of meaningful alternatives
DEFF Research Database (Denmark)
Leong, Tuck Wah; Iversen, Ole Sejer
2015-01-01
Participatory Design (PD) is inherently concerned with inquiring into and supporting human values when designing IT. We argue that a PD approach that is led by a focus upon participants' values can allow participants to discover meaningful alternatives -- alternative uses and alternative...... conceptualizations for IT that are particularly meaningful to them. However, how PD works with values in the design process has not been made explicit. In this paper, we aim to (i) explicate this values-led PD approach, (ii) illustrate how this approach can lead to outcomes that are meaningful alternatives, and (iii...
Revisiting the ADT mass of the five-dimensional rotating black holes with squashed horizons
Energy Technology Data Exchange (ETDEWEB)
Peng, Jun-Jin [Guizhou Normal University, Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing, Guiyang (China)
2017-10-15
We evaluate the Abbott-Deser-Tekin (ADT) mass of the five-dimensional rotating black holes with squashed horizons on two different on-shell reference backgrounds, which are the flat background and the boundary matched Kaluza-Klein (KK) monopole. The mass on the former, identified with the one on the background of the asymptotic geometry, differs from the mass on the latter by that of the KK monopole. However, each mass satisfies the first law of black hole thermodynamics. To test the results in five dimensions, we compute the mass in the context of the dimensionally reduced theory. Finally, in contrast with the original ADT formulation, its off-shell generalisation is applied to calculate the mass as well. (orig.)
Revisiting the ADT mass of the five-dimensional rotating black holes with squashed horizons
International Nuclear Information System (INIS)
Peng, Jun-Jin
2017-01-01
We evaluate the Abbott-Deser-Tekin (ADT) mass of the five-dimensional rotating black holes with squashed horizons on two different on-shell reference backgrounds, which are the flat background and the boundary matched Kaluza-Klein (KK) monopole. The mass on the former, identified with the one on the background of the asymptotic geometry, differs from the mass on the latter by that of the KK monopole. However, each mass satisfies the first law of black hole thermodynamics. To test the results in five dimensions, we compute the mass in the context of the dimensionally reduced theory. Finally, in contrast with the original ADT formulation, its off-shell generalisation is applied to calculate the mass as well. (orig.)
Revisiting the ADT mass of the five-dimensional rotating black holes with squashed horizons
Peng, Jun-Jin
2017-10-01
We evaluate the Abbott-Deser-Tekin (ADT) mass of the five-dimensional rotating black holes with squashed horizons on two different on-shell reference backgrounds, which are the flat background and the boundary matched Kaluza-Klein (KK) monopole. The mass on the former, identified with the one on the background of the asymptotic geometry, differs from the mass on the latter by that of the KK monopole. However, each mass satisfies the first law of black hole thermodynamics. To test the results in five dimensions, we compute the mass in the context of the dimensionally reduced theory. Finally, in contrast with the original ADT formulation, its off-shell generalisation is applied to calculate the mass as well.
The influence of time horizon on results of cost-effectiveness analyses.
Kim, David D; Wilkinson, Colby L; Pope, Elle F; Chambers, James D; Cohen, Joshua T; Neumann, Peter J
2017-12-01
Debates persist on the appropriate time horizon from a payer's perspective and how the time horizon in cost-effectiveness analysis (CEA) influences the value assessment. We systematically reviewed the Tufts Medical Center CEA Registry and identified US-based studies that used a payer perspective from 2005-2014. We classified the identified CEAs as short-term (time horizon ≤ 5 years) and long-term (> 5 years), and examined associations between study characteristics and the specified time horizon. We also developed case studies with selected interventions to further explore the relationship between time horizon and projected costs, benefits, and incremental cost-effectiveness ratios (ICER). Among 782 identified studies that met our inclusion criteria, 552 studies (71%) utilized a long-term time horizon while 198 studies (25%) used a short-term horizon. Among studies that employed multiple time horizons, the extension of the time horizon yielded more favorable ICERs in 19 cases and less favorable ICERs in 4 cases. Case studies showed the use of a longer time horizon also yielded more favorable ICERs. The assumed time horizon in CEAs can substantially influence the value assessment of medical interventions. To capture all consequences, we encourage the use of time horizons that extend sufficiently into the future.
Factors influencing organic-horizon carbon pools in mixed-species stands of central Maine, USA
Joshua J. Puhlick; Shawn Fraver; Ivan J. Fernandez; Aaron R. Weiskittel; Laura S. Kenefic; Randy Kolka; Marie-Cecile Gruselle
2016-01-01
The overall goal of this study was to evaluate the correlation of multiple abiotic and biotic factors with organic-horizon (O-horizon) carbon (C) content on the Penobscot Experimental Forest in central Maine, USA. O-horizon samples were collected and their associated depths were recorded from stands managed with a range of silvicultural and harvesting treatments (i.e...
Weakly Isolated horizons: first order actions and gauge symmetries
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 the
Weakly Isolated horizons: first order actions and gauge symmetries
International Nuclear Information System (INIS)
Corichi, Alejandro; Reyes, Juan D; Vukašinac, Tatjana
2017-01-01
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
Virasoro algebra with central charge c=1 on the horizon of a two-dimensional-Rindler space-time
International Nuclear Information System (INIS)
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 hcoloneμ 2 /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
Nypaver, Cynthia F; Shambley-Ebron, Donna
2016-11-01
In the United States, African American babies die more than twice as often as White babies. The cause for this difference remains elusive, yet is likely complex with one factor being inadequate cultural care of pregnant African American women. The purpose of this study was to explore African American women's perspectives of meaningful prenatal care. Community-based participatory research was employed for this study using photovoice. The sample included 11 African American mothers in an urban community in Midwestern United States. Five themes were abstracted from the data: (1) Access to Care; (2) Soul Nourishment; (3) Companionship; (4) Help Me, Teach Me; and (5) The Future. Meaningful prenatal care is influenced by culture. African American women need physical, social, and soulful support to enhance meaningfulness of care during pregnancy. The findings support that meaningfulness of prenatal care for African American women may be enhanced by accessible and uniquely designed, culturally congruent models of prenatal care. © The Author(s) 2015.
Can Ausubel's Theory of Meaningful Learning Become an Alternative to Piagetian Psychology?
Albert, Edna
1979-01-01
Discusses Novak's views that Ausubel's meaningful learning can become an alternative to Piagetian psychology and argues that Ausubel does not provide a theory that can be an alternative to Piaget's developmental psychology. (HM)
Dezutter, Jessie; Dewitte, Laura; Thauvoye, Evalyne; Vanhooren, Siebrecht
2017-02-01
Trying to cope with chronic pain is a highly demanding and challenging task and pain patients often need to reformulate goals or aspirations due to their pain condition. This goal violation is often related with experienced distress and requires coping processes in order to decrease the distress and stimulate a healthy adaptation. Some scholars, however, argued that in so-called unsolvable or irreparable stressors such as chronic pain, conventional coping strategies like problem-focused coping might not be the most adaptive option. In these situations, meaningful coping strategies attempting to transform the meaning of the stressful experience would be more accurate. In this study, we aim to test if goal violation triggers meaningful coping strategies over time and whether engagement in these meaningful coping strategies result in improved life satisfaction, as an indicator of adaptation. A longitudinal three wave study in a sample of paint patients (n = 125) tests whether goal violation triggers positive reappraisal and downward comparison, two possible meaningful coping strategies. The study furthermore tests if engagement in these strategies results in a better adaptation to the pain condition, reflected in higher life satisfaction. Results partially supported our hypotheses by pointing to the benevolent role of downward comparison on life satisfaction via decreased goal violation of pain patients. Our findings however did also show that positive reappraisal predicted lower life satisfaction via increased levels of appraised goal violation which questions the role of positive reappraisal as a genuine meaningful coping strategy. Implications and limitations are discussed. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.
Can geodesics in extra dimensions solve the cosmological horizon problem?
International Nuclear Information System (INIS)
Chung, Daniel J. H.; Freese, Katherine
2000-01-01
We demonstrate a non-inflationary solution to the cosmological horizon problem in scenarios in which our observable universe is confined to three spatial dimensions (a three-brane) embedded in a higher dimensional space. A signal traveling along an extra-dimensional null geodesic may leave our three-brane, travel into the extra dimensions, and subsequently return to a different place on our three-brane in a shorter time than the time a signal confined to our three-brane would take. Hence, these geodesics may connect distant points which would otherwise be ''outside'' the four dimensional horizon (points not in causal contact with one another). (c) 2000 The American Physical Society
Connecting horizon pixels and interior voxels of a black hole
International Nuclear Information System (INIS)
Nicolini, Piero; Singleton, Douglas
2014-01-01
In this paper we discuss to what extent one can infer details of the interior structure of a black hole based on its horizon. Recalling that black hole thermal properties are connected to the non-classical nature of gravity, we circumvent the restrictions of the no-hair theorem by postulating that the black hole interior is singularity free due to violations of the usual energy conditions. Further these conditions allow one to establish a one-to-one, holographic projection between Planckian areal “bits” on the horizon and “voxels”, representing the gravitational degrees of freedom in the black hole interior. We illustrate the repercussions of this idea by discussing an example of the black hole interior consisting of a de Sitter core postulated to arise from the local graviton quantum vacuum energy. It is shown that the black hole entropy can emerge as the statistical entropy of a gas of voxels
Black hole event horizons — Teleology and predictivity
Bhattacharya, Swastik; Shankaranarayanan, S.
2017-11-01
General Relativity predicts the existence of black holes. Access to the complete spacetime manifold is required to describe the black hole. This feature necessitates that black hole dynamics is specified by future or teleological boundary condition. Here, we demonstrate that the statistical mechanical description of black holes, the raison d’être behind the existence of black hole thermodynamics, requires teleological boundary condition. Within the fluid-gravity paradigm — Einstein’s equations when projected on spacetime horizons resemble Navier-Stokes equation of a fluid — we show that the specific heat and the coefficient of bulk viscosity of the horizon fluid are negative only if the teleological boundary condition is taken into account. We argue that in a quantum theory of gravity, the future boundary condition plays a crucial role. We briefly discuss the possible implications of this at late stages of black hole evaporation.
Dynamical Formation of Horizons in Recoiling D Branes
Ellis, Jonathan Richard; Nanopoulos, Dimitri V; Ellis, John
2000-01-01
A toy calculation of string/D-particle interactions within a world-sheet approach indicates that quantum recoil effects - reflecting the gravitational back-reaction on space-time foam due to the propagation of energetic particles - induces the appearance of a microscopic event horizon, or `bubble', inside which stable matter can exist. The scattering event causes this horizon to expand, but we expect quantum effects to cause it to contract again, in a `bounce' solution. Within such `bubbles', massless matter propagates with an effective velocity that is less than the velocity of light in vacuo, which may lead to observable violations of Lorentz symmetry that may be tested experimentally. The conformal invariance conditions in the interior geometry of the bubbles select preferentially three for the number of the spatial dimensions, corresponding to a consistent formulation of the interaction of D3 branes with recoiling D particles, which are allowed to fluctuate independently only on the D3-brane hypersurface.
Evolution of the cosmological horizons in a concordance universe
Energy Technology Data Exchange (ETDEWEB)
Margalef-Bentabol, Berta; Cepa, Jordi [Departamento de Astrofísica, Universidad de la Laguna, E-38205 La Laguna, Tenerife (Spain); Margalef-Bentabol, Juan, E-mail: bmb@cca.iac.es, E-mail: juanmargalef@estumail.ucm.es, E-mail: jcn@iac.es [Facultad de Ciencias Matemáticas, Universidad Complutense de Madrid, Madrid (Spain)
2012-12-01
The particle and event horizons are widely known and studied concepts, but the study of their properties, in particular their evolution, have only been done so far considering a single state equation in a decelerating universe. This paper is the first of two where we study this problem from a general point of view. Specifically, this paper is devoted to the study of the evolution of these cosmological horizons in an accelerated universe with two state equations, cosmological constant and dust. We have obtained simple expressions in terms of their respective recession velocities that generalize the previous results for one state equation only. With the equations of state considered, it is proved that both velocities remain always positive.
Accelerated detectors and worldsheet horizons in AdS/CFT
Chernicoff, Mariano; Paredes, Angel
2011-03-01
We use the AdS/CFT correspondence to discuss the response of an accelerated observer to the quantum vacuum fluctuations. In particular, we study heavy quarks probing a strongly coupled CFT by analysing strings moving in AdS. We propose that, in this context, a non-trivial detection rate is associated to the existence of a worldsheet horizon and we find an Unruh-like expression for the worldsheet temperature. Finally, by examining a rotating string in global AdS we find that there is a transition between string embeddings with and without worldsheet horizon. The dual picture corresponds to having non-trivial or trivial interaction with the quantum vacuum respectively. This is in qualitative agreement with results of Davies et al.
Robust receding horizon control for networked and distributed nonlinear systems
Li, Huiping
2017-01-01
This book offers a comprehensive, easy-to-understand overview of receding-horizon control for nonlinear networks. It presents novel general strategies that can simultaneously handle general nonlinear dynamics, system constraints, and disturbances arising in networked and large-scale systems and which can be widely applied. These receding-horizon-control-based strategies can achieve sub-optimal control performance while ensuring closed-loop stability: a feature attractive to engineers. The authors address the problems of networked and distributed control step-by-step, gradually increasing the level of challenge presented. The book first introduces the state-feedback control problems of nonlinear networked systems and then studies output feedback control problems. For large-scale nonlinear systems, disturbance is considered first, then communication delay separately, and lastly the simultaneous combination of delays and disturbances. Each chapter of this easy-to-follow book not only proposes and analyzes novel ...
Horizon wave-function and the quantum cosmic censorship
Directory of Open Access Journals (Sweden)
Roberto Casadio
2015-07-01
Full Text Available We investigate the Cosmic Censorship Conjecture by means of the horizon wave-function (HWF formalism. We consider a charged massive particle whose quantum mechanical state is represented by a spherically symmetric Gaussian wave-function, and restrict our attention to the superextremal case (with charge-to-mass ratio α>1, which is the prototype of a naked singularity in the classical theory. We find that one can still obtain a normalisable HWF for α22, and the uncertainty in the location of the horizon blows up at α2=2, signalling that such an object is no more well-defined. This perhaps implies that a quantum Cosmic Censorship might be conjectured by stating that no black holes with charge-to-mass ratio greater than a critical value (of the order of 2 can exist.
New perspectives for European climate services: HORIZON2020
Bruning, Claus; Tilche, Andrea
2014-05-01
The developing of new end-to-end climate services was one of the core priorities of 7th Framework for Research and Technological Development of the European Commission and will become one of the key strategic priorities of Societal Challenge 5 of HORIZON2020 (the new EU Framework Programme for Research and Innovation 2014-2020). Results should increase the competitiveness of European businesses, and the ability of regional and national authorities to make effective decisions in climate-sensitive sectors. In parallel, the production of new tailored climate information should strengthen the resilience of the European society to climate change. In this perspective the strategy to support and foster the underpinning science for climate services in HORIZON2020 will be presented.
Distribution load forecast with interactive correction of horizon loads
International Nuclear Information System (INIS)
Glamochanin, V.; Andonov, D.; Gagovski, I.
1994-01-01
This paper presents the interactive distribution load forecast application that performs the distribution load forecast with interactive correction of horizon loads. It consists of two major parts implemented in Fortran and Visual Basic. The Fortran part is used for the forecasts computations. It consists of two methods: Load Transfer Coupling Curve Fitting (LTCCF) and load Forecast Using Curve Shape Clustering (FUCSC). LTCCF is used to 'correct' the contaminated data because of load transfer among neighboring distribution areas. FUCSC uses curve shape clustering to forecast the distribution loads of small areas. The forecast for each small area is achieved by using the shape of corresponding cluster curve. The comparison of forecasted loads of the area with historical data will be used as a tool for the correction of the estimated horizon load. The Visual Basic part is used to provide flexible interactive user-friendly environment. (author). 5 refs., 3 figs
Audio-Visual and Meaningful Semantic Context Enhancements in Older and Younger Adults.
Directory of Open Access Journals (Sweden)
Kirsten E Smayda
Full Text Available Speech perception is critical to everyday life. Oftentimes noise can degrade a speech signal; however, because of the cues available to the listener, such as visual and semantic cues, noise rarely prevents conversations from continuing. The interaction of visual and semantic cues in aiding speech perception has been studied in young adults, but the extent to which these two cues interact for older adults has not been studied. To investigate the effect of visual and semantic cues on speech perception in older and younger adults, we recruited forty-five young adults (ages 18-35 and thirty-three older adults (ages 60-90 to participate in a speech perception task. Participants were presented with semantically meaningful and anomalous sentences in audio-only and audio-visual conditions. We hypothesized that young adults would outperform older adults across SNRs, modalities, and semantic contexts. In addition, we hypothesized that both young and older adults would receive a greater benefit from a semantically meaningful context in the audio-visual relative to audio-only modality. We predicted that young adults would receive greater visual benefit in semantically meaningful contexts relative to anomalous contexts. However, we predicted that older adults could receive a greater visual benefit in either semantically meaningful or anomalous contexts. Results suggested that in the most supportive context, that is, semantically meaningful sentences presented in the audiovisual modality, older adults performed similarly to young adults. In addition, both groups received the same amount of visual and meaningful benefit. Lastly, across groups, a semantically meaningful context provided more benefit in the audio-visual modality relative to the audio-only modality, and the presence of visual cues provided more benefit in semantically meaningful contexts relative to anomalous contexts. These results suggest that older adults can perceive speech as well as younger
Sungkit, Flavia Norpina; Meiyanto, IJK Sito
2015-01-01
The purpose of the study is to investigate the influence of job enrichment toward employee engagement through psychological meaningfulness as the mediator. Research design used is a cross-sectional study of 112 employees. Data is analyzed by multiple linear regression analysis. Result shows job enrichment is able to influence employee engagement significantly through psychological meaningfulness as the mediator. The p=0,000 with significance level 0,05. The sig F change shows 0,006, which is
Invasion science: a horizon scan of emerging challenges and opportunities
Czech Academy of Sciences Publication Activity Database
Riccardi, A.; Blackburn, T. M.; Carlton, J. T.; Dick, J. T. A.; Hulme, P. E.; Iacarella, J. C.; Jeschke, J.M.; Liebhold, A. M.; Lockwood, J. L.; MacIsaac, H. J.; Pyšek, Petr; Richardson, D. M.; Ruiz, G. M.; Simberloff, D.; Sutherland, W. J.; Wardle, D. A.; Aldridge, D.
2017-01-01
Roč. 32, č. 6 (2017), s. 464-474 ISSN 0169-5347 R&D Projects: GA ČR GB14-36079G Grant - others:AV ČR(CZ) AP1002 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985939 Keywords : biological invsions * research topics * horizon scanning Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 15.268, year: 2016
New Horizons Regional Education Center 2001 FIRST Robotics Competition
2001-01-01
The New Horizons Regional Education Center (NHREC) in Hampton, VA sought and received NASA funding to support its participation in the 2001 FIRST Robotics competition. FIRST, Inc. (For Inspiration and Recognition of Science and Technology) is an organization which encourages the application of creative science, math, and computer science principles to solve real-world engineering problems. The FIRST competition is an international engineering contest featuring high school, government, and business partnerships.
New Horizons Regional Education Center 1999 FIRST Robotics Competition
Purman, Richard I.
1999-01-01
The New Horizons Regional Education Center (NHREC) in Hampton, VA sought and received NASA funding to support its participation in the 1999 FIRST Robotics competition. FIRST, Inc. (For Inspiration and Recognition of Science and Technology) is an organization which encourages the application of creative science, math, and computer science principles to solve real-world engineering problems. The FIRST competition is an international engineering contest featuring high school, government, and business partnerships.
Typical event horizons in AdS/CFT
Energy Technology Data Exchange (ETDEWEB)
Avery, Steven G.; Lowe, David A. [Department of Physics, Brown University,Providence, RI 02912 (United States)
2016-01-14
We consider the construction of local bulk operators in a black hole background dual to a pure state in conformal field theory. The properties of these operators in a microcanonical ensemble are studied. It has been argued in the literature that typical states in such an ensemble contain firewalls, or otherwise singular horizons. We argue this conclusion can be avoided with a proper definition of the interior operators.
Typical event horizons in AdS/CFT
Avery, Steven G.; Lowe, David A.
2016-01-01
We consider the construction of local bulk operators in a black hole background dual to a pure state in conformal field theory. The properties of these operators in a microcanonical ensemble are studied. It has been argued in the literature that typical states in such an ensemble contain firewalls, or otherwise singular horizons. We argue this conclusion can be avoided with a proper definition of the interior operators.
Does horizon entropy satisfy a quantum null energy conjecture?
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.
Formulation for less master production schedule instability under rolling horizon
Herrera , Carlos; Thomas , André
2009-01-01
International audience; In Manufacturing Planning and Control Systems, the Master Production Schedule (MPS) makes a link between tactical and operational levels, taking into account information provided by end items, demand forecast as well as Sales and Operations Planning (S&OP) suggestions. Therefore, MPS plays an important role to maintain an adequate customers service level and an efficient production system. In a rolling planning horizon, MPS is periodically computed over whole operation...
Observational signature of high spin at the Event Horizon Telescope
Gralla, Samuel E.; Lupsasca, Alexandru; Strominger, Andrew
2018-04-01
We analytically compute the observational appearance of an isotropically emitting point source on a circular, equatorial orbit near the horizon of a rapidly spinning black hole. The primary image moves on a vertical line segment, in contrast to the primarily horizontal motion of the spinless case. Secondary images, also on the vertical line, display a rich caustic structure. If detected, this unique signature could serve as a `smoking gun' for a high spin black hole in nature.
Near the horizon of 5D black rings
International Nuclear Information System (INIS)
Loran, Farhang; Soltanpanahi, Hesam
2009-01-01
For the five dimensional N = 2 black rings, we study the supersymmetry enhancement and identify the global supergroup of the near horizon geometry. We show that the global part of the supergroup is OSp(4*|2) x U(1) which is similar to the small black string. We show that results obtained by applying the entropy function formalism, the c-extremization approach and the Brown-Henneaux method to the black ring solution are in agreement with the microscopic entropy calculation.
Infinite Horizon Discrete Time Control Problems for Bounded Processes
Directory of Open Access Journals (Sweden)
2009-03-01
Full Text Available We establish Pontryagin Maximum Principles in the strong form for infinite horizon optimal control problems for bounded processes, for systems governed by difference equations. Results due to Ioffe and Tihomirov are among the tools used to prove our theorems. We write necessary conditions with weakened hypotheses of concavity and without invertibility, and we provide new results on the adjoint variable. We show links between bounded problems and nonbounded ones. We also give sufficient conditions of optimality.
Submesoscale dispersion in the vicinity of the Deepwater Horizon spill
Poje, Andrew C.; Özgökmen, Tamay M.; Lipphardt, Bruce L.; Haus, Brian K.; Ryan, Edward H.; Haza, Angelique C.; Jacobs, Gregg A.; Reniers, A. J. H. M.; Olascoaga, Maria Josefina; Novelli, Guillaume; Griffa, Annalisa; Beron-Vera, Francisco J.; Chen, Shuyi S.; Coelho, Emanuel; Hogan, Patrick J.
2014-01-01
Reliable forecasts for the dispersion of oceanic contamination are important for coastal 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 incident in the Pacific Ocean in 2011. Accurate prediction of pollutant pathways and concentrations at the ocean surface requires understanding ocean dynamics over a broad range of spatial scales. Fundamental questions concerning the structure of the velocity fi...
Summary and status of the Horizons ephemeris system
Giorgini, J.
2011-10-01
Since 1996, the Horizons system has provided searchable access to JPL ephemerides for all known solar system bodies, several dozen spacecraft, planetary system barycenters, and some libration points. Responding to 18 400 000 requests from 300 000 unique addresses, the system has recently averaged 420 000 ephemeris requests per month. Horizons is accessed and automated using three interfaces: interactive telnet, web-browser form, and e-mail command-file. Asteroid and comet ephemerides are numerically integrated from JPL's database of initial conditions. This small-body database is updated hourly by a separate process as new measurements and discoveries are reported by the Minor Planet Center and automatically incorporated into new JPL orbit solutions. Ephemerides for other objects are derived by interpolating previously developed solutions whose trajectories have been represented in a file. For asteroids and comets, such files may be dynamically created and transferred to users, effectively recording integrator output. These small-body SPK files may then be interpolated by user software to reproduce the trajectory without duplicating the numerically integrated n-body dynamical model or PPN equations of motion. Other Horizons output is numerical and in the form of plain-text observer, vector, osculating element, or close-approach tables, typically expected be read by other software as input. About one hundred quantities can be requested in various time-scales and coordinate systems. For JPL small-body solutions, this includes statistical uncertainties derived from measurement covariance and state transition matrices. With the exception of some natural satellites, Horizons is consistent with DE405/DE406, the IAU 1976 constants, ITRF93, and IAU2009 rotational models.
Surface tension of the horizon and Archimedes' principle for gravity
Shu, Liangsuo; Cui, Kaifeng; Liu, Xiaokang; Liu, Zhichun; Liu, Wei
2018-01-01
In this letter, by combining the holographic principle with the graviton Bose-Einstein condensates hypothesis of gravitational backgrounds, we provide a theory of gravity, which provides some kinetic details of how the gravitational coupling between matter and spacetime works. The effective radial potential energy of an object in a gravitational field is found to be the sum of the interfacial energy caused by its micro horizon and the energy required to make room for it by displacing graviton...
Horizon wave-function and the quantum cosmic censorship
Casadio, RobertoDipartimento di Fisica e Astronomia, Alma Mater Università di Bologna, via Irnerio 46, Bologna, 40126, Italy; Micu, Octavian(Institute of Space Science, Bucharest, P.O. Box MG-23, Bucharest-Magurele, RO-077125, Romania); Stojkovic, Dejan(HEPCOS, Department of Physics, SUNY at Buffalo, Buffalo, NY, 14260-1500, United States)
2015-01-01
We investigate the Cosmic Censorship Conjecture by means of the horizon wave-function (HWF) formalism. We consider a charged massive particle whose quantum mechanical state is represented by a spherically symmetric Gaussian wave-function, and restrict our attention to the superxtremal case (with charge-to-mass ratio $\\alpha>1$), which is the prototype of a naked singularity in the classical theory. We find that one can still obtain a normalisable HWF for $\\alpha^2 2$, and the uncertainty in t...
Reaping the benefits of meaningful work: The mediating versus moderating role of work engagement.
Johnson, Matthew J; Jiang, Lixin
2017-08-01
This study examined whether meaningful work may improve one's quality of life outside of the workplace (i.e., work-to-life enrichment). More importantly, we proposed and tested competing hypotheses regarding the role of work engagement in the relationship between meaningful work and work-to-life enrichment. Specifically, we investigated whether work engagement served as a mediator of this relationship, as suggested by the job demands-resources model, or instead a moderator, as suggested by conservation of resources theory. Two-wave survey data were collected from 194 respondents recruited via Amazon Mechanical Turk. Analyses showed that meaningful work was positively related to work-to-life enrichment over time (i.e., 3 months later). Additionally, work engagement mediated but did not moderate the relationship between meaningful work at Time 1 and work-to-life enrichment at Time 2. We suggest that organizations foster a sense of meaningfulness in employees to facilitate engagement and in turn enrich employees' lives beyond the workplace. Therefore, not only organizations, but individuals as well may reap the benefits of meaningful work. Copyright © 2016 John Wiley & Sons, Ltd.
EAKMAN, AARON M.; CARLSON, MIKE E.; CLARK, FLORENCE A.
2011-01-01
The Meaningful Activity Participation Assessment (MAPA), a recently developed 28-item tool designed to measure the meaningfulness of activity, was tested in a sample of 154 older adults. The MAPA evidenced a sufficient level of internal consistency and test-retest reliability and correlated as theoretically predicted with the Life Satisfaction Index-Z, the Satisfaction with Life Scale, the Engagement in Meaningful Activities Survey, the Purpose in Life Test, the Center for Epidemiologic Studies Depression Inventory and the Rand SF-36v2 Health Survey subscales. Zero-order correlations consistently demonstrated meaningful relationships between the MAPA and scales of psychosocial well-being and health-related quality of life. Results from multiple regression analyses further substantiated these findings, as greater meaningful activity participation was associated with better psychological well-being and health-related quality of life. The MAPA appears to be a reliable and valid measure of meaningful activity, incorporating both subjective and objective indicators of activity engagement. PMID:20649161
Hawking spectrum for a fiber-optical analog of the event horizon
Bermudez, David; Leonhardt, Ulf
2016-05-01
Hawking radiation has been regarded as a more general phenomenon than in gravitational physics, in particular in laboratory analogs of the event horizon. Here we consider the fiber-optical analog of the event horizon, where intense light pulses in fibers establish horizons for probe light. Then, we calculate the Hawking spectrum in an experimentally realizable system. We found that the Hawking radiation is peaked around group-velocity horizons in which the speed of the pulse matches the group velocity of the probe light. The radiation nearly vanishes at the phase horizon where the speed of the pulse matches the phase velocity of light.
Investment horizon heterogeneity and wavelet: Overview and further research directions
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.
Horizon Wavefunction of Generalized Uncertainty Principle Black Holes
Directory of Open Access Journals (Sweden)
Luciano Manfredi
2016-01-01
Full Text Available We study the Horizon Wavefunction (HWF description of a Generalized Uncertainty Principle inspired metric that admits sub-Planckian black holes, where the black hole mass m is replaced by M=m1+β/2MPl2/m2. Considering the case of a wave-packet shaped by a Gaussian distribution, we compute the HWF and the probability PBH that the source is a (quantum black hole, that is, that it lies within its horizon radius. The case β0, where a minimum in PBH is encountered, thus meaning that every particle has some probability of decaying to a black hole. Furthermore, for sufficiently large β we find that every particle is a quantum black hole, in agreement with the intuitive effect of increasing β, which creates larger M and RH terms. This is likely due to a “dimensional reduction” feature of the model, where the black hole characteristics for sub-Planckian black holes mimic those in (1+1 dimensions and the horizon size grows as RH~M-1.
Effective horizons, junction conditions and large-scale magnetism
Energy Technology Data Exchange (ETDEWEB)
Giovannini, Massimo [CERN, Department of Physics, Theory Division, Geneva (Switzerland); INFN, Milan (Italy)
2017-08-15
The quantum mechanical generation of hypermagnetic and hyperelectric fields in four-dimensional conformally flat background geometries rests on the simultaneous continuity of the effective horizon and of the extrinsic curvature across the inflationary boundary. The junction conditions for the gauge fields are derived in general terms and corroborated by explicit examples with particular attention to the limit of a sudden (but nonetheless continuous) transition of the effective horizon. After reducing the dynamics to a pair of integral equations related by duality transformations, we compute the power spectra and deduce a novel class of logarithmic corrections which turn out to be, however, numerically insignificant and overwhelmed by the conductivity effects once the gauge modes reenter the effective horizon. In this perspective the magnetogenesis requirements and the role of the postinflationary conductivity are clarified and reappraised. As long as the total duration of the inflationary phase is nearly minimal, quasi-flat hypermagnetic power spectra are comparatively more common than in the case of vacuum initial data. (orig.)
A Receding Horizon Controller for the Steam Generator Water Level
International Nuclear Information System (INIS)
Na, Man Gyun; Lee, Yoon Joon
2003-01-01
In this work, the receding horizon control method was used to control the water level of nuclear steam generators and applied to two linear models and also a nonlinear model of steam generators. A receding horizon control method is to solve an optimization problem for finite future steps at current time and to implement the first optimal control input as the current control input. The procedure is then repeated at each subsequent instant. The dynamics of steam generators is very different according to power levels. The receding horizon controller is designed by using a reduced linear steam generator model fixed over a certain power range and applied to a Westinghouse-type (U-tube recirculating type) nuclear steam generator. The proposed controller designed at a fixed power level shows good performance for any other power level within this power range. The steam generator shows actually nonlinear characteristics. Therefore, the proposed algorithm is implemented for a nonlinear model of the nuclear steam generator to verify its real performance and also shows good responses
Addressing the long time horizon for managing used nuclear fuel
International Nuclear Information System (INIS)
Hodge, R.A.
2006-01-01
The time horizon that must be considered in developing an approach to managing used nuclear fuel extends many thousands of years. Such a time horizon is without precedent in environmental, economic, social, technical and public policy terms. As a first step in addressing this issue, the Nuclear Waste Management Organization convened a team of 33 individuals to undertake a formal scenarios exercise. Such an exercise is a way of framing potential futures that might occur. There is no intent to predict the future. This exercise represents the first time that the scenarios technique has been used for such a long time horizon. The approach involved identifying two principle axes of potential change: (1) social - political - environmental well-being; and (2) magnitude of the used nuclear fuel challenge. Using this organizing template, four scenarios were developed reaching out 25 years, and an additional twelve were developed at 175 years branching out from the original four. In addition, a series of sixteen possible 'end-points' were identified to span conditions 500 years out and for 10,000 years a large number of 'what- ifs' were developed. The scenarios, end-points, and what- ifs were then used to identify a number of criteria that could be used for testing proposed management options and their capacity to deal with future conditions. This paper describes this work and the role that it has played in the deliberations of the Nuclear Waste Management Organization. (author)
Horizon effects with surface waves on moving water
Energy Technology Data Exchange (ETDEWEB)
Rousseaux, Germain; Maissa, Philippe; Mathis, Christian; Coullet, Pierre [Universite de Nice-Sophia Antipolis, Laboratoire J-A Dieudonne, UMR CNRS-UNS 6621, Parc Valrose, 06108 Nice Cedex 02 (France); Philbin, Thomas G; Leonhardt, Ulf, E-mail: Germain.Rousseaux@unice.f [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom)
2010-09-15
Surface waves on a stationary flow of water are considered in a linear model that includes the surface tension of the fluid. The resulting gravity-capillary waves experience a rich array of horizon effects when propagating against the flow. In some cases, three horizons (points where the group velocity of the wave reverses) exist for waves with a single laboratory frequency. Some of these effects are familiar in fluid mechanics under the name of wave blocking, but other aspects, in particular waves with negative co-moving frequency and the Hawking effect, were overlooked until surface waves were investigated as examples of analogue gravity (Schuetzhold R and Unruh W G 2002 Phys. Rev. D 66 044019). A comprehensive presentation of the various horizon effects for gravity-capillary waves is given, with emphasis on the deep water/ short wavelength case kh>>1, where many analytical results can be derived. A similarity of the state space of the waves to that of a thermodynamic system is pointed out.
Possible Evidence for an Event Horizon in Cyg XR-1
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.
Peering beyond the horizon with standard sirens and redshift drift
Jimenez, Raul; Raccanelli, Alvise; Verde, Licia; Matarrese, Sabino
2018-04-01
An interesting test on the nature of the Universe is to measure the global spatial curvature of the metric in a model independent way, at a level of |Ωk|limit of |Ωk|<10‑4 would yield stringent tests on several models of inflation. Further, improving the constraint by an order of magnitude would help in reducing "model confusion" in standard parameter estimation. Moreover, if the curvature is measured to be at the value of the amplitude of the CMB fluctuations, it would offer a powerful test on the inflationary paradigm and would indicate that our Universe must be significantly larger than the current horizon. On the contrary, in the context of standard inflation, measuring a value above CMB fluctuations will lead us to conclude that the Universe is not much larger than the current observed horizon; this can also be interpreted as the presence of large fluctuations outside the horizon. However, it has proven difficult, so far, to find observables that can achieve such level of accuracy, and, most of all, be model-independent. Here we propose a method that can in principle achieve that; this is done by making minimal assumptions and using distance probes that are cosmology-independent: gravitational waves, redshift drift and cosmic chronometers. We discuss what kind of observations are needed in principle to achieve the desired accuracy.
Anomalous current in periodic Lorentz gases with infinite horizon
Energy Technology Data Exchange (ETDEWEB)
Dolgopyat, Dmitrii I [University of Maryland, College Park (United States); Chernov, Nikolai I [University of Alabama at Birmingham, Birmingham, Alabama (United States)
2009-08-31
Electric current is studied in a two-dimensional periodic Lorentz gas in the presence of a weak homogeneous electric field. When the horizon is finite, that is, free flights between collisions are bounded, the resulting current J is proportional to the voltage difference E, that is, J=1/2 D*E+o(||E||), where D* is the diffusion matrix of a Lorentz particle moving freely without an electric field (see a mathematical proof). This formula agrees with Ohm's classical law and the Einstein relation. Here the more difficult model with an infinite horizon is investigated. It is found that infinite corridors between scatterers allow the particles (electrons) to move faster, resulting in an abnormal current (causing 'superconductivity'). More precisely, the current is now given by J=1/2 DE| log||E|| | + O(||E||), where D is the 'superdiffusion' matrix of a Lorentz particle moving freely without an electric field. This means that Ohm's law fails in this regime, but the Einstein relation (suitably interpreted) still holds. New results are also obtained for the infinite-horizon Lorentz gas without external fields, complementing recent studies by Szasz and Varju. Bibliography: 31 titles.
Anomalous current in periodic Lorentz gases with infinite horizon
International Nuclear Information System (INIS)
Dolgopyat, Dmitrii I; Chernov, Nikolai I
2009-01-01
Electric current is studied in a two-dimensional periodic Lorentz gas in the presence of a weak homogeneous electric field. When the horizon is finite, that is, free flights between collisions are bounded, the resulting current J is proportional to the voltage difference E, that is, J=1/2 D*E+o(||E||), where D* is the diffusion matrix of a Lorentz particle moving freely without an electric field (see a mathematical proof). This formula agrees with Ohm's classical law and the Einstein relation. Here the more difficult model with an infinite horizon is investigated. It is found that infinite corridors between scatterers allow the particles (electrons) to move faster, resulting in an abnormal current (causing 'superconductivity'). More precisely, the current is now given by J=1/2 DE| log||E|| | + O(||E||), where D is the 'superdiffusion' matrix of a Lorentz particle moving freely without an electric field. This means that Ohm's law fails in this regime, but the Einstein relation (suitably interpreted) still holds. New results are also obtained for the infinite-horizon Lorentz gas without external fields, complementing recent studies by Szasz and Varju. Bibliography: 31 titles.
Isolated Horizons and Black Hole Entropy in Loop Quantum Gravity
Directory of Open Access Journals (Sweden)
Jacobo Diaz-Polo
2012-08-01
Full Text Available We review the black hole entropy calculation in the framework of Loop Quantum Gravity based on the quasi-local definition of a black hole encoded in the isolated horizon formalism. We show, by means of the covariant phase space framework, the appearance in the conserved symplectic structure of a boundary term corresponding to a Chern-Simons theory on the horizon and present its quantization both in the U(1 gauge fixed version and in the fully SU(2 invariant one. We then describe the boundary degrees of freedom counting techniques developed for an infinite value of the Chern-Simons level case and, less rigorously, for the case of a finite value. This allows us to perform a comparison between the U(1 and SU(2 approaches and provide a state of the art analysis of their common features and different implications for the entropy calculations. In particular, we comment on different points of view regarding the nature of the horizon degrees of freedom and the role played by the Barbero-Immirzi parameter. We conclude by presenting some of the most recent results concerning possible observational tests for theory.
Euclidean scalar Green's functions near the black hole and black brane horizons
International Nuclear Information System (INIS)
Haba, Z
2009-01-01
We discuss approximations of the Riemannian geometry near the horizon. If a (D + 1)-dimensional manifold N has a bifurcate Killing horizon then we approximate N by a product of the two-dimensional Rindler space R 2 and a (D - 1)-dimensional Riemannian manifold M. We obtain approximate formulae for scalar Green's functions. We study the behavior of the Green's functions near the horizon and their dimensional reduction. We show that if M is compact then the Green's function near the horizon can be approximated by the Green's function of the two-dimensional quantum field theory. The correction term is exponentially small away from the horizon. We extend the results to black brane solutions of supergravity in 10 and 11 dimensions. The near-horizon geometry can be approximated by N=AdS p xS q . We discuss the Euclidean Green's functions on N and their behavior near the horizon.
Van Wingerden, Jessica; van der Stoep, Joost; Poell, R.F.
2018-01-01
This study examines the impact of meaningful work on employees’ level of work engagement as mediated by perceived opportunities to craft and job crafting. Based on the literature on meaningful work and job crafting, we hypothesize that meaningful work has a positive relationship with an employee’s
Department of Transportation — The Standard Reference Tables (SRT) provide consistent reference data for the various applications that support Flight Standards Service (AFS) business processes and...
Demands–abilities fit, work beliefs, meaningful work and engagement in nature-based jobs
Directory of Open Access Journals (Sweden)
Nellie de Crom
2018-03-01
Full Text Available Orientation: Meaningful work and personal engagement are important dimensions of flourishing of employees, especially when individuals work in challenging jobs. Research purpose: This study aimed to investigate the relationship between demands–abilities fit, work beliefs, meaningful work and engagement in individuals in nature-based jobs. Motivation for the study: Individuals working in nature often work under challenging circumstances without the necessary resources. A research gap exists regarding the effects of demands–abilities fit and work beliefs on meaningful work. It is also not clear how these antecedents and meaningful work will impact the engagement of individuals working in nature. Research approach, design and method: A cross-sectional survey was used with a convenience sample of 161 nature-based employees. Data were collected using a structured online questionnaire consisting of items from the demands–abilities fit scale, work–life questionnaire, work and meaning Inventory, work engagement scale and a biographical questionnaire. Main findings: Work beliefs (calling, career and job and demands–abilities fit predicted a large percentage of the variance in meaning making. Work beliefs (calling and job and demands–abilities fit also predicted a large percentage of the variance in greater good motivations. Demands–abilities fit and a calling work orientation indirectly affected work engagement via meaningful work. The scales which measured calling and job orientations showed insufficient discriminant validity in relation to the scales which measured positive meaning and work engagement. Practical and managerial implications: Managers should consider implementing interventions to affect the demands–abilities fit (through human resource management interventions and work beliefs of individuals working in nature (through job crafting. Promoting perceptions of meaningful work might contribute to higher personal engagement
Microbiomes structure and diversity in different horizons of full soil profiles
Chernov, Timofey; Tkhakakhova, Azida; Zhelezova, Alena; Semenov, Mikhail; Kutovaya, Olga
2017-04-01
Topsoil is a most common object for soil metagenomic studies; sometimes soil profile is being formally split in layers by depth. However, Russian Soil Science School formulated the idea of soil profile as a complex of soil horizons, which can differ in their properties and genesis. In this research we analyzed 57 genetic soil horizons of 8 different soils from European part of Russia: Albeluvisol, Greyzemic Phaeozem, three Chermozems (different land use - till, fallow, wind-protecting tree line), Rhodic Cambisol, Haplic Kastanozem and Salic Solonetz (WRB classification). Sampling was performed from all genetic horizons in each soil profile starting from topsoil until subsoil. Total DNA was extracted and 16S rRNA sequencing was provided together with chemical analysis of soil (pH measurement, C and N contents, etc.). Structure and diversity of prokaryotic community are significantly different in those soil horizons, which chemical properties and processes of origin are contrasting with nearest horizons: Na-enriched horizon of Solonetz, eluvial horizon of Albeluvisol, plough pan of Agrochernozem. Actinobacteria were abundant in top horizons of soils in warm and dry climate, while Acidobacteria had the highest frequency in soils of moist and cold regions. Concerning Archaea, Thaumarchaeota prevailed in all studied soils. Their rate was higher in microbiomes of upper horizons of steppe soils and it was reducing with depth down the profile. Prokaryotic communities in Chernozems were clustered by soil horizons types: microbiomes of A (organic topsoil) and B (mineral) horizons formed non-overlapping clusters by principal component analysis, cluster formed by prokaryotic communities of transitional soil horizons (AB) take place between clusters of A and B horizons. Moreover, prokaryotic communities of A horizons differ from each other strongly, while microbiomes of B horizons formed a narrow small cluster. It must be explaned by more diverse conditions in upper A horizons
Entropy bound of horizons for accelerating, rotating and charged Plebanski–Demianski black hole
International Nuclear Information System (INIS)
Debnath, Ujjal
2016-01-01
We first review the accelerating, rotating and charged Plebanski–Demianski (PD) black hole, which includes the Kerr–Newman rotating black hole and the Taub-NUT spacetime. The main feature of this black hole is that it has 4 horizons like event horizon, Cauchy horizon and two accelerating horizons. In the non-extremal case, the surface area, entropy, surface gravity, temperature, angular velocity, Komar energy and irreducible mass on the event horizon and Cauchy horizon are presented for PD black hole. The entropy product, temperature product, Komar energy product and irreducible mass product have been found for event horizon and Cauchy horizon. Also their sums are found for both horizons. All these relations are dependent on the mass of the PD black hole and other parameters. So all the products are not universal for PD black hole. The entropy and area bounds for two horizons have been investigated. Also we found the Christodoulou–Ruffini mass for extremal PD black hole. Finally, using first law of thermodynamics, we also found the Smarr relation for PD black hole.
Entropy bound of horizons for accelerating, rotating and charged Plebanski–Demianski black hole
Energy Technology Data Exchange (ETDEWEB)
Debnath, Ujjal, E-mail: ujjaldebnath@yahoo.com
2016-09-15
We first review the accelerating, rotating and charged Plebanski–Demianski (PD) black hole, which includes the Kerr–Newman rotating black hole and the Taub-NUT spacetime. The main feature of this black hole is that it has 4 horizons like event horizon, Cauchy horizon and two accelerating horizons. In the non-extremal case, the surface area, entropy, surface gravity, temperature, angular velocity, Komar energy and irreducible mass on the event horizon and Cauchy horizon are presented for PD black hole. The entropy product, temperature product, Komar energy product and irreducible mass product have been found for event horizon and Cauchy horizon. Also their sums are found for both horizons. All these relations are dependent on the mass of the PD black hole and other parameters. So all the products are not universal for PD black hole. The entropy and area bounds for two horizons have been investigated. Also we found the Christodoulou–Ruffini mass for extremal PD black hole. Finally, using first law of thermodynamics, we also found the Smarr relation for PD black hole.
Singularities and horizons in the collisions of gravitational waves
International Nuclear Information System (INIS)
Yurtsever, U.H.
1989-01-01
This thesis presents a study of the dynamical, nonlinear interaction of colliding gravitational waves, as described by classical general relativity. In the work on the collisions of exactly-plane waves, it is shown that Killing horizons in any plane-symmetric spacetime are unstable against small plane-symmetric perturbations. It is thus concluded that the Killing-Cauchy horizons produced by the collisions of some exactly plane gravitational waves are nongeneric, and the generic initial data for the colliding plane waves always produce pure spacetime singularities without such horizons. This conclusion is later proved rigorously (using the full nonlinear theory rather than perturbation theory), in connection with an analysis of the asymptotic singularity structure of a general colliding plane-wave spacetime. This analysis also proves that asymptotically the singularities created by colliding plane waves are of inhomogeneous-Kasner type; the asymptotic Kasner axes and exponents of these singularities in general depend on the spatial coordinate that runs tangentially to the singularity in the non-plane-symmetric direction. In the work on collisions of almost-plane gravitational waves, first some general properties of single almost-plane gravitational-wave spacetimes are explored. It is shown that, by contrast with an exact plane wave, an almost-plane gravitational wave cannot have a propagation direction that is Killing; i.e., it must diffract and disperse as it propagates. It is also shown that an almost-plane wave cannot be precisely sandwiched between two null wave-fronts; i.e., it must leave behind tails in the spacetime region through which is passes
Near horizon geometry of rotating black holes in five dimensions
International Nuclear Information System (INIS)
Cvetic, M.; Larsen, F.
1998-01-01
We interpret the general rotating black holes in five dimensions as rotating black strings in six dimensions. In the near-horizon limit the geometry is locally AdS 3 x S 3 , as in the non-rotating case. However, the global structure couples the AdS 3 and the S 3 , giving angular velocity to the S 3 . The asymptotic geometry is exploited to count the microstates and recover the precise value of the Bekenstein-Hawking entropy, with rotation taken properly into account. We discuss the perturbation spectrum of the rotating black hole, and its relation to the underlying conformal field theory. (orig.)
Receding Horizon Trajectory Optimization with Terminal Impact Specifications
Directory of Open Access Journals (Sweden)
Limin Zhang
2014-01-01
Full Text Available The trajectory optimization problem subject to terminal impact time and angle specifications can be reformulated as a nonlinear programming problem using the Gauss pseudospectral method. The cost function of the trajectory optimization problem is modified to reduce the terminal control energy. A receding horizon optimization strategy is implemented to reject the errors caused by the motion of a surface target. Several simulations were performed to validate the proposed method via the C programming language. The simulation results demonstrate the effectiveness of the proposed algorithm and that the real-time requirement can be easily achieved if the C programming language is used to realize it.
Accelerated detectors and worldsheet horizons in AdS/CFT
Chernicoff, Mariano; Paredes, Angel
2010-01-01
We use the AdS/CFT correspondence to discuss the response of an accelerated observer to the quantum vacuum fluctuations. In particular, we study heavy quarks probing a strongly coupled CFT by analysing strings moving in AdS. We propose that, in this context, a non-trivial detection rate is associated to the existence of a worldsheet horizon and we find an Unruh-like expression for the worldsheet temperature. Finally, by examining a rotating string in global AdS we find that there is a transit...
Backward Stochastic H2/H∞ Control: Infinite Horizon Case
Directory of Open Access Journals (Sweden)
Zhen Wu
2014-01-01
Full Text Available The mixed H2/H∞ control problem is studied for systems governed by infinite horizon backward stochastic differential equations (BSDEs with exogenous disturbance signal. A necessary and sufficient condition for the existence of a unique solution to the H2/H∞ control problem is derived. The equivalent feedback solution is also discussed. Contrary to deterministic or stochastic forward case, the feedback solution is no longer feedback of the current state; rather, it is feedback of the entire history of the state.
On cosmic censorship: do compact Cauchy horizons imply symmetry?
International Nuclear Information System (INIS)
Isenberg, J.; Moncrief, V.
1983-01-01
The basic idea of Cosmic Censorship is that, in a physically reasonable spacetime, an observer should not encounter any naked singularities. The authors discuss some new results which provide strong support for one of the statements of Cosmic Censorship: Strong Cosmic Censorship says that the maximal spacetime development of a set of Cauchy data on a spacelike initial surface (evolved via the vacuum Einstein equations, the Einstein-Maxwell equations, or some other 'reasonable' set) will not be extendible across a Cauchy horizon. (Auth.)
New worldwide horizons for the International Organization of Psychophysiology (IOP).
Mangina, C A
2000-12-01
This Presidential Address deals with the new challenges and horizons of the International Organization of Psychophysiology (IOP) as we are marching towards the 21st century. The importance of Clinical Psychophysiology to humanity is emphasized. The special contribution of the International Journal of Psychophysiology to the future of Psychophysiology as a world forum is underlined. The status of Psychophysiology as a leading neuroscientific discipline is described and the role and major contributions of the late Dr Herbert Jasper as Co-Founding Honorary Fellow of IOP is highlighted.
Gravitational entropy and thermodynamics away from the horizon
Energy Technology Data Exchange (ETDEWEB)
Brustein, Ram, E-mail: ramyb@bgu.ac.il [Department of Physics, Ben-Gurion University, Beer-Sheva 84105 (Israel); CAS, Ludwig-Maximilians-Universitaet Muenchen, 80333 Muenchen (Germany); Medved, A.J.M., E-mail: j.medved@ru.ac.za [Department of Physics and Electronics, Rhodes University, Grahamstown 6140 (South Africa)
2012-08-29
We define, by an integral of geometric quantities over a spherical shell of arbitrary radius, an invariant gravitational entropy. This definition relies on defining a gravitational energy and pressure, and it reduces at the horizon of both black branes and black holes to Wald's Noether charge entropy. We support the thermodynamic interpretation of the proposed entropy by showing that, for some cases, the field theory duals of the entropy, energy and pressure are the same as the corresponding quantities in the field theory. In this context, the Einstein equations are equivalent to the field theory thermodynamic relation TdS=dE+PdV supplemented by an equation of state.
Energy Technology Data Exchange (ETDEWEB)
Sanfilippo, Antonio P.; Calapristi, Augustin J.; Crow, Vernon L.; Hetzler, Elizabeth G.; Turner, Alan E.
2004-05-26
We present an approach to the disambiguation of cluster labels that capitalizes on the notion of semantic similarity to assign WordNet senses to cluster labels. The approach provides interesting insights on how document clustering can provide the basis for developing a novel approach to word sense disambiguation.
Lieff, Susan J
2009-10-01
Retention of faculty in academic medicine is a growing challenge. It has been suggested that inattention to the humanistic values of the faculty is contributing to this problem. Professional development should consider faculty members' search for meaning, purpose, and professional fulfillment and should support the development of an ability to reflect on these issues. Ensuring the alignment of academic physicians' inner direction with their outer context is critical to professional fulfillment and effectiveness. Personal reflection on the synergy of one's strengths, passions, and values can help faculty members define meaningful work so as to enable clearer career decision making. The premise of this article is that an awareness of and the pursuit of meaningful work and its alignment with the academic context are important considerations in the professional fulfillment and retention of academic faculty. A conceptual framework for understanding meaningful work and alignment and ways in which that framework can be applied and taught in development programs are presented and discussed.
Students’ Expectations and Experiences of Meaningful Simulation-Based Medical Education
Directory of Open Access Journals (Sweden)
Tuulikki Keskitalo
2016-11-01
Full Text Available This study aims to investigate students’ expectations and experiences of meaningful learning in simulation-based learning environments. We set the following research question: How do students’ experiences of meaningful simulation-based learning correspond to their expectations? The students’ (n = 87; male 51, female 36 pre- and post-questionnaires were analyzed using statistical methods. The results indicated that students’ expectations and experiences of meaningful learning were positive, and for most statements, there were statistically significant differences between the mean pre-questionnaire rating and the mean post-questionnaire rating, thereby indicating that students’ actual experiences of simulation-based learning were more positive than their expectations. Thus, students’ experiences exceeded their expectations.
"Meaningful use" of electronic health records and its relevance to laboratories and pathologists
Directory of Open Access Journals (Sweden)
Walter H Henricks
2011-01-01
Full Text Available Electronic health records (EHRs have emerged as a major topic in health care and are central to the federal government′s strategy for transforming healthcare delivery in the United States. Recent federal actions that aim to promote the use of EHRs promise to have significant implications for laboratories and for pathology practices. Under the HITECH (Health Information Technology Economic and Clinical Health Act, an EHR incentive program has been established through which individual physicians and hospitals can qualify to receive incentive payments if they achieve "meaningful use" of "certified" EHR technology. The rule also establishes payment penalties in future years for eligible providers who have not met the requirements for meaningful use of EHRs. Meaningful use must be achieved using EHR technology that has been certified in accordance with functional and technical criteria that are set forth a regulation that parallels the meaningful use criteria in the incentive program. These actions and regulations are important to laboratories and pathologists for a number of reasons. Several of the criteria and requirements in the meaningful use rules and EHR certification criteria relate directly or indirectly to laboratory testing and laboratory information management, and future stage requirements are expected to impact the laboratory as well. Furthermore, as EHR uptake expands, there will be greater expectations for electronic interchange of laboratory information and laboratory information system (LIS-EHR interfaces. Laboratories will need to be aware of the technical, operational, and business challenges that they may face as expectations for LIS-EHR increase. This paper reviews the important recent federal efforts aimed at accelerating EHR use, including the incentive program for EHR meaningful use, provider eligibility, and EHR certification criteria, from a perspective of their relevance for laboratories and pathology practices.
2002 reference document; Document de reference 2002
Energy Technology Data Exchange (ETDEWEB)
NONE
2002-07-01
This 2002 reference document of the group Areva, provides information on the society. Organized in seven chapters, it presents the persons responsible for the reference document and for auditing the financial statements, information pertaining to the transaction, general information on the company and share capital, information on company operation, changes and future prospects, assets, financial position, financial performance, information on company management and executive board and supervisory board, recent developments and future prospects. (A.L.B.)
Bowens, Felicia M; Frye, Patricia A; Jones, Warren A
2010-10-01
This article examines the role that clinical workflow plays in successful implementation and meaningful use of electronic health record (EHR) technology in ambulatory care. The benefits and barriers of implementing EHRs in ambulatory care settings are discussed. The researchers conclude that widespread adoption and meaningful use of EHR technology rely on the successful integration of health information technology (HIT) into clinical workflow. Without successful integration of HIT into clinical workflow, clinicians in today's ambulatory care settings will continue to resist adoption and implementation of EHR technology.
Directory of Open Access Journals (Sweden)
Felipe Damasio
2015-12-01
Full Text Available Researchers in science teaching have advocated concomitant education about and of science. To approach the nature and history of science in basic education is necessary to have an epistemological approach that can go between of rationalism of Bunge and relativism of Feyerabend. In this paper, it is argued that Feyerabend's epistemological stance is that more can help promote meaningful learning critical, so as to form inquiring, flexible, creative, innovative, tolerant and liberal people. In addition, the suggestions Feyerabend's epistemology also complement the Theory of Meaningful Learning Critical to propose a curriculum and a context for the principles of the theory are in science classrooms.
DEFF Research Database (Denmark)
Nicic, Sara; Nørby, Karina; Bruun Johansen, Clea
2014-01-01
of this study was to investigate the applicability of these concepts of positive psychological theory in a patient education setting. Methods: This pilot study combines participating observation of group based patient education and 8 qualitative interviews with 4 patients with type 2 diabetes. Meaning......Abstract Background: The aim of this pilot study was to explore patient experiences of meaningfulness and flow related to group based patient education in type 2 diabetes. Meaningfulness and flow are underexposed as psychological learning concepts in patient education, and the ambition...
Creating a meaningful infection control program: one home healthcare agency's lessons.
Poff, Renee McCoy; Browning, Sarah Via
2014-03-01
Creating a meaningful infection control program in the home care setting proved to be challenging for agency leaders of one hospital-based home healthcare agency. Challenges arose when agency leaders provided infection control (IC) data to the hospital's IC Committee. The IC Section Chief asked for national benchmark comparisons to align home healthcare reporting to that of the hospital level. At that point, it was evident that the home healthcare IC program lacked definition and structure. The purpose of this article is to share how one agency built a meaningful IC program.
Improving students' meaningful learning on the predictive nature of quantum mechanics
Directory of Open Access Journals (Sweden)
Rodolfo Alves de Carvalho Neto
2009-03-01
Full Text Available This paper deals with research about teaching quantum mechanics to 3rd year high school students and their meaningful learning of its predictive aspect; it is based on the Master’s dissertation of one of the authors (CARVALHO NETO, 2006. While teaching quantum mechanics, we emphasized its predictive and essentially probabilistic nature, based on Niels Bohr’s complementarity interpretation (BOHR, 1958. In this context, we have discussed the possibility of predicting measurement results in well-defined experimental contexts, even for individual events. Interviews with students reveal that they have used quantum mechanical ideas, suggesting their meaningful learning of the essentially probabilistic predictions of quantum mechanics.
On the membrane paradigm and spontaneous breaking of horizon BMS symmetries
International Nuclear Information System (INIS)
Eling, Christopher; Oz, Yaron
2016-01-01
We consider a BMS-type symmetry action on isolated horizons in asymptotically flat spacetimes. From the viewpoint of the non-relativistic field theory on a horizon membrane, supertranslations shift the field theory spatial momentum. The latter is related by a Ward identity to the particle number symmetry current and is spontaneously broken. The corresponding Goldstone boson shifts the horizon angular momentum and can be detected quantum mechanically. Similarly, area preserving superrotations are spontaneously broken on the horizon membrane and we identify the corresponding gapless modes. In asymptotically AdS spacetimes we study the BMS-type symmetry action on the horizon in a holographic superfluid dual. We identify the horizon supertranslation Goldstone boson as the holographic superfluid Goldstone mode.
Signalling, entanglement and quantum evolution beyond Cauchy horizons
International Nuclear Information System (INIS)
Yurtsever, Ulvi; Hockney, George
2005-01-01
Consider a bipartite entangled system, half of which falls through the event horizon of an evaporating black hole, while the other half remains coherently accessible to experiments in the exterior region. Beyond complete evaporation, the evolution of the quantum state past the Cauchy horizon cannot remain unitary, raising the questions: how can this evolution be described as a quantum map, and how is causality preserved? What are the possible effects of such non-standard quantum evolution maps on the behaviour of the entangled laboratory partner? More generally, the laws of quantum evolution under extreme conditions in remote regions (not just in evaporating black-hole interiors, but possibly near other naked singularities and regions of extreme spacetime structure) remain untested by observation, and might conceivably be non-unitary or even nonlinear, raising the same questions about the evolution of entangled states. The answers to these questions are subtle, and are linked in unexpected ways to the fundamental laws of quantum mechanics. We show that terrestrial experiments can be designed to probe and constrain exactly how the laws of quantum evolution might be altered, either by black-hole evaporation, or by other extreme processes in remote regions possibly governed by unknown physics
Computing security strategies in finite horizon repeated Bayesian games
Lichun Li
2017-07-10
This paper studies security strategies in two-player zero-sum repeated Bayesian games with finite horizon. In such games, each player has a private type which is independently chosen according to a publicly known a priori probability. Players\\' types are fixed all through the game. The game is played for finite stages. At every stage, players simultaneously choose their actions which are observed by the public. The one-stage payoff of player 1 (or penalty to player 2) depends on both players types and actions, and is not directly observed by any player. While player 1 aims to maximize the total payoff over the game, player 2 wants to minimize it. This paper provides each player two ways to compute the security strategy, i.e. the optimal strategy in the worst case. First, a security strategy that directly depends on both players\\' history actions is derived by refining the sequence form. Noticing that history action space grows exponentially with respect to the time horizon, this paper further presents a security strategy that depends on player\\'s fixed sized sufficient statistics. The sufficient statistics is shown to consist of the belief on one\\'s own type, the regret on the other player\\'s type, and the stage, and is independent of the other player\\'s strategy.
Minimal incorporation of Deepwater Horizon oil by estuarine filter feeders
International Nuclear Information System (INIS)
Fry, Brian; Anderson, Laurie C.
2014-01-01
Highlights: • Oil from the Deepwater Horizon oil spill entered Louisiana bays in mid-2010. • Oil was used minimally (<1%) in diets of mussels and barnacles. • Also, oil did not enhance planktonic respiration rates. • Use of oil carbon was relatively small in these productive estuarine food webs. - Abstract: Natural abundance carbon isotope analyses are sensitive tracers for fates and use of oil in aquatic environments. Use of oil carbon in estuarine food webs should lead to isotope values approaching those of oil itself, −27‰ for stable carbon isotopes reflecting oil origins and −1000‰ for carbon-14 reflecting oil age. To test for transfer of oil from the 2010 Deepwater Horizon spill into estuarine food webs, filter-feeding barnacles (Balanus sp.) and marsh mussels (Geukensia demissa) were collected from Louisiana estuaries near the site of the oil spill. Carbon-14 analyses of these animals from open waters and oiled marshes showed that oil use was <1% and near detection limits estimated at 0.3% oil incorporation. Respiration studies showed no evidence for enhanced microbial activity in bay waters. Results are consistent with low dietary impacts of oil for filter feeders and little overall impact on respiration in the productive Louisiana estuarine systems
Stability of black holes based on horizon thermodynamics
Directory of Open Access Journals (Sweden)
Meng-Sen Ma
2015-12-01
Full Text Available On the basis of horizon thermodynamics we study the thermodynamic stability of black holes constructed in general relativity and Gauss–Bonnet gravity. In the framework of horizon thermodynamics there are only five thermodynamic variables E, P, V, T, S. It is not necessary to consider concrete matter fields, which may contribute to the pressure of black hole thermodynamic system. In non-vacuum cases, we can derive the equation of state, P=P(V,T. According to the requirements of stable equilibrium in conventional thermodynamics, we start from these thermodynamic variables to calculate the heat capacity at constant pressure and Gibbs free energy and analyze the local and global thermodynamic stability of black holes. It is shown that P>0 is the necessary condition for black holes in general relativity to be thermodynamically stable, however this condition cannot be satisfied by many black holes in general relativity. For black hole in Gauss–Bonnet gravity negative pressure can be feasible, but only local stable black hole exists in this case.
The Thermodynamic Evolution of the Cosmological Event Horizon
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.
Black Hole Event Horizons and Advection-Dominated Accretion
McClintock, Jeffrey; Mushotzky, Richard F. (Technical Monitor)
2002-01-01
The work supported in part by this grant is part of a larger program on the detection of black hole event horizons, which is also partially supported by NASA grant GO0-1105A. This work has been carried out primarily in collaboration with Dr. M. Garcia and Prof. R. Narayan at the Harvard-Smithsonian Center for Astrophysics and with D. Barret and J. Hameury at Centre d'Etude Spoliate des Rayonnements, France. Our purpose is to confirm the existence of black-hole event horizons by comparing accreting black holes to secreting neutron stars in quiescent X-ray novae. Such a comparison is feasible because black holes and neutron stars are both present in similar environments in X-ray novae. Our second purpose is to assess the nature of accretion flows onto black holes at very low mass transfer rates. Observations of some XMM targets are still pending, whereas most of the Chandra observations have been completed. We anticipate further publications on this work in the future.
From Rindler horizon to mini black holes at LHC
Energy Technology Data Exchange (ETDEWEB)
Ghaffary, Tooraj [Islamic Azad University, Department of Science, Shiraz Branch, Shiraz (Iran, Islamic Republic of)
2017-02-15
Recently researchers (A. Sepehri et al., Astrophys. Space Sci. 344, 79 (2013)) have considered the signature of superstring balls near mini black holes at LHC and calculate the information loss for these types of strings. Motivated by their work, we consider the evolution of events in high energy experiments from lower energies for which the Rindler horizon is formed to higher energies in which mini black holes and string balls are emerged. Extending the Gottesman and Preskill method to string theory, we find the information loss for excited strings ''string balls'' in mini black holes at LHC and calculate the information transformation from the collapsing matter to the state of outgoing Hawking radiation for strings. We come to the conclusion that information transformation for high energy strings is complete. Then the thermal distribution of excited strings near mini black holes at LHC is calculated. In order to obtain the total string cross section near black holes produced in proton-proton collision, we multiply the black hole production cross section by the thermal distribution of strings. It is observed that many high energy excited strings are produced near the event horizon of TeV black holes. These excited strings evaporate to standard model particles like Higgs boson and top quark at Hagedorn temperature. We derive the production cross section for these particles due to string ball decay at LHC and consider their decay to light particles like bottom quarks and gluons. (orig.)
Horizon of quantum black holes in various dimensions
Directory of Open Access Journals (Sweden)
Roberto Casadio
2016-09-01
Full Text Available 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 PBH3. 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.
Time orientation, planning horizons and responsibility into the future
International Nuclear Information System (INIS)
Svenson, O.; Nilsson, G.
1988-01-01
Subjects of four categories (social science students, engineering students, retired people and nuclear waste experts) were asked about past events, planning, risks and future time with emphasis on energy related issues and in particular questions concerning spent nuclear waste. Among, the results reported it was found that events in the past were located more or less correctly and that events further back systematically too close to the present. Today's responsibility into the future was judged to cover 3 to 6 generations ahead and an adequate planning horizon for a local community to be on the average 11 to 14 years. Adequate planning horizons for the handling of spent nuclear fuel were judged to be from 100 to 500 years. The responsibility for effects of today's decisions was judged to be from about 100 to 300 years into the future for environmental pollution and from about 50 to 600 years for nuclear waste. However, non-negliqable proportions of the subjects choose a more moral standpoint and gave answers indicating that responsibility had to be unlimited. Some sex differences were found and an interaction with age offered as a hypothesis to be investigated in the future. Interrelations between clusters of questions revealed some links from past time and planning to judgements of environmental and nuclear power related risks. (orig.)
The Science and Prospects of Astrophysical Observations with New Horizons
Nguyen, Chi; Zemcov, Michael; Cooray, Asantha; Lisse, Carey; Poppe, Andrew
2018-01-01
Astrophysical observation from the outer solar system provides a unique and quiet vantage point from which to understand our cosmos. If properly designed, such observations enable several niche science cases that are difficult or impossible to perform near Earth. NASA's New Horizons mission includes several instruments with ~10cm telescopes that provide imaging capability from UV to near-IR wavelengths with moderate spectral resolution. A carefully designed survey can optimize the expendable propellant and limited data telemetry bandwidth to allow several unique measurements, including a detailed understanding of the cosmic extragalactic background light in the optical and near-IR, studies of the local and extragalactic UV background, measurements of the properties of dust and ice in the outer solar system, searches for moons and other faint structures around exoplanets, and determinations of the mass of planets far from their parent stars using gravitational microlensing. New Horizons is currently in an extended mission, that will conclude in 2021, designed to survey distant objects in the Kuiper Belt at high phase angles and perform a close flyby of KBO 2014 MU69. Afterwards, the astrophysics community will have a unique, generational opportunity to use this mission for astronomical observations at heliocentric distances beyond 50 AU. In this poster, we present the science case for an extended 2021 - 2026 astrophysics mission, and discuss some of the practical considerations that must be addressed to maximize the potential science return.
Afsarmanesh, H.; Camarinha-Matos, L.M.; Ermilova, E.; Camarinha-Matos, L.M.; Afsarmanesh, H.; Ollus, M.
2008-01-01
Defining a comprehensive and generic "reference framework" for Virtual organizations Breeding Environments (VBEs), addressing all their features and characteristics, is challenging. While the definition and modeling of VBEs has become more formalized during the last five years, "reference models"
CMS Statistics Reference Booklet
U.S. Department of Health & Human Services — The annual CMS Statistics reference booklet provides a quick reference for summary information about health expenditures and the Medicare and Medicaid health...
International Nuclear Information System (INIS)
Porteus, E.
1982-01-01
The study of infinite-horizon nonstationary dynamic programs using the operator approach is continued. The point of view here differs slightly from that taken by others, in that Denardo's local income function is not used as a starting point. Infinite-horizon values are defined as limits of finite-horizon values, as the horizons get long. Two important conditions of an earlier paper are weakened, yet the optimality equations, the optimality criterion, and the existence of optimal ''structured'' strategies are still obtained
A redefinition of Hawking temperature on the event horizon: Thermodynamical equilibrium
International Nuclear Information System (INIS)
Saha, Subhajit; Chakraborty, Subenoy
2012-01-01
In this Letter we have used the recently introduced redefined Hawking temperature on the event horizon and investigated whether the generalized second law of thermodynamics (GSLT) and thermodynamic equilibrium holds for both the event and the apparent horizons. Here we have considered FRW universe and examined the GSLT and thermodynamic equilibrium with three examples. Finally, we have concluded that from the thermodynamic viewpoint, the universe bounded by the event horizon is more realistic than that by the apparent horizon at least for some examples.
How to write a competitive proposal for Horizon 2020 a research manager's handbook
McCarthy, Sean
2013-01-01
Chapter 1: An Overview of Horizon 2020 ; Chapter 2: How the Research Priorities were Selected (How to Lobby) ; Chapter 3: The Research Priorities in Horizon 2020 ; Chapter 4: How Proposals are Evaluated ; Chapter 5: How to Write the ‘Impact’ of the project ; Chapter 6: The One Page Proposal ; Chapter 7: How to Streamline Proposal Writing ; Chapter 8: How to Find the Best Partners ; Chapter 9: How to Write the ‘Implementation' of the project ; Chapter 10: Legal and Financial Rules in Horizon 2020 ; Chapter 11: What is your Strategy for Horizon 2020?
Changing quantum reference frames
Palmer, Matthew C.; Girelli, Florian; Bartlett, Stephen D.
2013-01-01
We consider the process of changing reference frames in the case where the reference frames are quantum systems. We find that, as part of this process, decoherence is necessarily induced on any quantum system described relative to these frames. We explore this process with examples involving reference frames for phase and orientation. Quantifying the effect of changing quantum reference frames serves as a first step in developing a relativity principle for theories in which all objects includ...
Parent Perceptions of Time Spent Meaningfully by Young Adults with Pervasive Support Needs
Rossetti, Zachary; Lehr, Donna; Lederer, Leslie; Pelerin, Dana; Huang, Shuoxi
2015-01-01
This article describes a qualitative study that examined how 23 young adults with pervasive support needs and limited functional communication spent their time and how their parents (n = 23) and direct support professionals (DSPs; n = 2) defined meaningfulness in relation to the young adults' experiences. Data were collected through…
Galloway, Kelli R.; Bretz, Stacey Lowery
2015-01-01
Research on laboratory learning points to the need to better understand what and how students learn in the undergraduate chemistry laboratory. The Meaningful Learning in the Laboratory Instrument (MLLI) was administered to general and organic chemistry students from 15 colleges and universities across the United States in order to measure the…
Pedagogical Background for Technology Education--Meaningful Learning in Theory and Practice
Autio, Ossi
2009-01-01
One important theme in technology education is the growing need to develop the type of pedagogies that encourage pupils in authentic and meaningful learning experiences. Often, the teaching strategies of technology education are only a matter of teaching the handling of materials and tools, and the production of mere objects does not consider how…
Galloway, Kelli R.; Bretz, Stacey Lowery
2015-01-01
The Meaningful Learning in the Laboratory Instrument (MLLI) was designed to measure students' cognitive and affective learning in the university chemistry laboratory. The MLLI was administered at the beginning and the end of the first semester to first-year university chemistry students to measure their expectations and experiences for learning in…
Meaningful Gamification and Students' Motivation: A Strategy for Scaffolding Reading Material
Ling, Lynette Tan Yuen
2018-01-01
Gamification is an innovative pedagogical strategy where digital games are used in an educational setting and as an aid to learning. Recent publications on gamification in the classroom investigate the concept of "meaningful gamification," where, in line with Ryan and Deci's self-determination theory, competency, autonomy, and…
Vachliotis, Theodoros; Salta, Katerina; Tzougraki, Chryssa
2014-01-01
The purpose of this study was dual: First, to develop and validate assessment schemes for assessing 11th grade students' meaningful understanding of organic chemistry concepts, as well as their systems thinking skills in the domain. Second, to explore the relationship between the two constructs of interest based on students' performance…
What constitutes meaningful engagement for patients and families as partners on research teams?
Black, Agnes; Strain, Kimberly; Wallsworth, Christine; Charlton, Sara-Grey; Chang, Wilma; McNamee, Kate; Hamilton, Clayon
2018-01-01
Objective There is growing emphasis on health care organizations to ensure that lay people are meaningfully engaged as partners on research teams. Our aim was to explore the perspectives of patients, family members and informal caregivers who have been involved on health care research teams in Canada and elicit their recommendations for meaningful engagement. Methods We conducted a qualitative study guided by thematic analysis of transcripts of focus groups and interviews of 19 experienced patient research partners in Canada. Results We identified four main themes: research environment, expectations, support and value, which highlight participants' combined perspectives on important factors to ensure their engagement in research is meaningful. Conclusions Our findings add to the evolving evidence base on the perspectives of lay people involved in health care research and their recommendations for research leaders on meaningful engagement. Our study suggests that research leaders should provide a welcoming research environment, outline appropriate expectations for patient research partners on research teams, support patient research partners' engagement in projects and recognize the value patient research partners bring to health research.
ten Klooster, Peter M.; Drossaers-Bakker, K.W.; Taal, Erik; van de Laar, Mart A F J
2006-01-01
The assessment of clinically meaningful changes in patient-reported pain has become increasingly important when interpreting results of clinical studies. However, proposed response criteria, such as the minimal clinically important difference, do not correspond with the growing need for information
75 FR 28331 - Meaningful Access to United States Currency for Blind and Visually Impaired Persons
2010-05-20
... feature is used in some foreign currency, and the Study's data indicated that this feature was more... Currency for Blind and Visually Impaired Persons AGENCY: Bureau of Engraving and Printing, Department of... meaningful access to U.S. currency to people who are blind and visually impaired pursuant to section 504 of...
DEFF Research Database (Denmark)
Andresen, Mette
2014-01-01
, values and beliefs in the center formed the base in the development of the tool. Aim: To develop an observational tool which can identify meaningful activities among elderly demented nursing home residents and thereby provide staff with more knowledge and possibilities for inviting and engaging residents...
Callings, Work Role Fit, Psychological Meaningfulness and Work Engagement among Teachers in Zambia
Rothmann, Sebastiaan; Hamukang'andu, Lukondo
2013-01-01
Our aim in this study was to investigate the relationships among a calling orientation, work role fit, psychological meaningfulness and work engagement of teachers in Zambia. A quantitative approach was followed and a cross-sectional survey was used. The sample (n = 150) included 75 basic and 75 secondary school teachers in the Choma district of…
Kanter, David E.
2010-01-01
Project-based science curricula can improve students' usable or meaningful understanding of the science content underlying a project. However, such curricula designed around "performances" wherein students design or make something do not always do this. We researched ways to design performance project-based science curricula (pPBSc) to better…
Towards a More Meaningful Involvement of Librarians in Academic Program Reviews
Bowker, Lynne
2018-01-01
Purpose: Using a descriptive case study approach, this paper aims to validate academic librarians' perceptions that they are marginalized by faculty during academic program reviews, and recommends ways for the two groups to collaborate more effectively to make program reviews more meaningful. Design/methodology/approach: The paper describes a case…
Bush-Mecenas, Susan; Marsh, Julie A.; Montes de Oca, David; Hough, Heather
2018-01-01
School accountability and improvement policy are on the precipice of a paradigm shift. While the multiple-measure dashboard accountability approach holds great promise for promoting more meaningful learning opportunities for all students, our research indicates that this can come with substantial challenges in practice. We reflect upon the lessons…
Beyond Needs Analysis: Soft Systems Methodology for Meaningful Collaboration in EAP Course Design
Tajino, Akira; James, Robert; Kijima, Kyoichi
2005-01-01
Designing an EAP course requires collaboration among various concerned stakeholders, including students, subject teachers, institutional administrators and EAP teachers themselves. While needs analysis is often considered fundamental to EAP, alternative research methodologies may be required to facilitate meaningful collaboration between these…
Meaningfulness for creation of growth in Small- and Medium-sized enterprises
DEFF Research Database (Denmark)
Brink, Tove; Neville, Mette
2016-01-01
The research in this paper reveals how meaningfulness of growth can be created in Small- and Medium-sized Enterprises (SMEs). The research is conducted in a four-year period with 24 SMEs participating from different industry branches. The research is now in the late part of the 3rd. year starting...
Community-based medical education: is success a result of meaningful personal learning experiences?
Kelly, Len; Walters, Lucie; Rosenthal, David
2014-01-01
Community-based medical education (CBME) is the delivery of medical education in a specific social context. Learners become a part of social and medical communities where their learning occurs. Longitudinal integrated clerkships (LICs) are year-long community-based placements where the curriculum and clinical experience is typically delivered by primary care physicians. These programs have proven to be robust learning environments, where learners develop strong communication skills and excellent clinical reasoning. To date, no learning model has been offered to describe CBME. The characteristics of CBME are explored by the authors who suggest that the social and professional context provided in small communities enhances medical education. The authors postulate that meaningfulness is engendered by the authentic context, which develops over time. These relationships with preceptors, patients and the community provide meaningfulness, which in turn enhances learning. The authors develop a novel learning model. They propose that the context-rich environment of CBME allows for meaningful relationships and experiences for students and that such meaningfulness enhances learning.
Meaningful Learning in the Teaching of Culture: The Project Based Learning Approach
Kean, Ang Chooi; Kwe, Ngu Moi
2014-01-01
This paper reports on a collaborative effort taken by a team of three teacher educators in using the Project Based Learning (PBL) approach in the teaching of Japanese culture with the aim to investigate the presence of actual "meaningful learning" among 15 students of a 12-Week Preparatory Japanese Language course under a teacher…
Magnitude and meaningfulness of change in SF-36 scores in four types of orthopedic surgery
DEFF Research Database (Denmark)
Busija, Lucy; Osborne, Richard H; Nilsdotter, Anna
2008-01-01
BACKGROUND: The Medical Outcomes General Health Survey (SF-36) is a widely used health status measure; however, limited evidence is available for its performance in orthopedic settings. The aim of this study was to examine the magnitude and meaningfulness of change and sensitivity of SF-36...
Finding pathways to more equitable and meaningful public-scientist partnerships
Daniela Soleri; Jonathan W. Long; Monica D. Ramirez-Andreotta; Ruth Eitemiller; Rajul Pandyaǁ
2016-01-01
For many, citizen science is exciting because of the possibility for more diverse, equitable partnerships in scientific research with outcomes considered meaningful and useful by all, including public participants. This was the focus of a symposium we organized at the 2015 conference of the Citizen Science Association. Here we synthesize points made by symposium...
The categorisation of dysthymic disorder: Can its constituents be meaningfully apportioned?
Rhebergen, D.; Graham, R.; Hadzi-Pavlovic, D.; Stek, M.L.; Friend, P.; Barrett, M.; Parker, G.
2012-01-01
Background: Since its introduction in DSM-III, the validity of dysthymia has been debated. Our objective is to further examine the concept of dysthymia in an outpatient sample, and explore whether its constituents can be meaningfully apportioned. Methods: 318 patients attending the Black Dog
Kato, Fumie; Spring, Ryan; Mori, Chikako
2016-01-01
Providing learners of a foreign language with meaningful opportunities for interactions, specifically with native speakers, is especially challenging for instructors. One way to overcome this obstacle is through video-synchronous computer-mediated communication tools such as Skype software. This study reports quantitative and qualitative data from…
Meaningful Share Generation for Increased Number of Secrets in Visual Secret-Sharing Scheme
Directory of Open Access Journals (Sweden)
Mustafa Ulutas
2010-01-01
Full Text Available This paper presents a new scheme for hiding two halftone secret images into two meaningful shares created from halftone cover images. Meaningful shares are more desirable than noise-like (meaningless shares in Visual Secret Sharing because they look natural and do not attract eavesdroppers' attention. Previous works in the field focus on either increasing number of secrets or creating meaningful shares for one secret image. The method outlined in this paper both increases the number of secrets and creates meaningful shares at the same time. While the contrast ratio of shares is equal to that of Extended Visual Cryptography, two secrets are encoded into two shares as opposed to one secret in the Extended Visual Cryptography. Any two natural-looking images can be used as cover unlike the Halftone Visual Cryptography method where one cover should be the negative of the other cover image and can only encode one secret. Effectiveness of the proposed method is verified by an experiment.